DESC:FIELD OF INVENTION
[001] The present invention relates to metallic compounds and devices comprising metallic compounds. Particularly, the present disclosure relates to devices comprising metallic compounds with redox active organic ligands. BACKGROUND OF INVENTION 5
[002] Rapid development of electronic devices and data storage equipments, has led to designing novel organic materials with a definite memory switching mechanism. Despite these devices having numerous advantages, most of the conventionally employed memory devices often face problems such as unclear switching behaviours and ambiguous structure–property relationships. The clarity 10 disparity in the working mechanism of switching behaviours results in the difficulty to achieve optimised results in switching efficiency. Recently, incorporating metallic moieties into memory devices as active materials has emerged as an efficient strategy in organic electronics.
[003] Metallic compounds utilize the advantages of the metal centres, which can 15 afford unique electronic properties and photoluminescence behaviour. Due to the coordination complex nature, the electronic movement and structural features lead to the field-driven polarization or redox transitions in the compounds which results in better switching behaviour. The enhanced switching behaviour makes these metallic compounds a better candidate as an active material to be used in the 20 memory devices. Further, metallic compounds having multiple redox states can result in better switching efficiency.
[004] In the context of modern computing systems, the emergence of artificial intelligence (AI) has led to increasing interest in the application of analog systems. Analog computing systems are known for their ability to process continuous data, 25 which is particularly useful in AI applications, such as neural networks and signal processing. These systems operate by manipulating continuous electrical signals to perform computations, unlike digital systems that process discrete binary data.
[005] Neuromorphic computing seeks to mimic the neural structure of the human brain to create energy-efficient and scalable systems capable of complex tasks. 30 Neuromorphic systems often employ memristors as synaptic weights in artificial
2
neural networks due to their ability to store multiple states, thereby enabling the representation of synaptic weights with high precision. Vector matrix multiplication (VMM) is a common operation in many computing algorithms, including those used in AI and machine learning. However, the implementation of VMM in traditional digital computing systems can be time and energy-intensive due to the 5 large number of computational steps involved.
[006] Dot product engines (DPEs) have been developed as a type of analog accelerator that can perform VMM in a single time-step, thereby increasing computational efficiency. Despite the technical advantages that such devices provide, the main difficulty lies in achieving analog precision in such memory 10 devices. Existing neuromorphic devices (e.g. metal oxide or 2D or phase change materials) only offer 2-6-bit analog precision which restricts the application of neuromorphic platforms for defined computation problems. Such devices however cannot be efficiently used for core computing operations in neural network training, signal and image processing. This limitation arises, amongst other factors, due to 15 stochastic ion diffusion and filamentary mechanism.
[007] Further, the conventionally employed memory devices exploit compounds that exhibit limited capacitive states and rely on resistive properties. This poses another challenge in conventionally available memory switching devices which store data as conductance levels. As a result, any operations would entail drawing 20 higher currents in instances when conductance levels are high. This in turn may lead to higher dissipative losses thus resulting in inefficiencies.
[008] Development of memory devices having multiple non-volatile stabilized capacitive or resistive states is hence a need of the hour. Considering the presence of a redox-active metal centre in metallic compounds, it provides a redox-controlled 25 switching mechanism, that could guarantee the write–read–erase–read (WRER) cycle realization. Hence, the devices can invoke highly-robust reprogrammable memory behaviours as a result of the above-mentioned redox-active effect of metal centre. Furthermore, another demand in the field of memory devices is the need for developing an active layer comprising active compounds, wherein the active layer 30 has an optimized relative permittivity. 3
[009] Therefore, owing to the increasing demand for advanced memory devices having metallic materials having multiple redox states, stable capacitive states and an optimized relative permittivity there exists a need in the art to develop metallic compounds with multiple redox states, better relative permittivity and having non-volatile stabilized capacitive states in order to be used in thin-film devices with 5 memristive and electrical switching properties. SUMMARY OF THE INVENTION
[0010] In an aspect of the present disclosure, there is provided a compound of Formula I 10
Formula I
wherein X1 and X1’ are independently selected from Cl, Br, I, NCS, SCN, or N3;
M1 is selected from Cr, Mn, Fe, Co, Ni, Os, Pt, Pd, Ru, Rh, or Ir; and
R’ is absent or is selected from -NC-C1-10 alkyl, or -NC-C6-15 aryl; 15
R1 and R2 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof; and
refers to presence or absence of a bond. 20
[0011] In another aspect of the present disclosure, there is provided a compound of Formula II
25 4
Formula II
wherein M2 is a transition group metal; and Ar1 and Ar2 are independently selected
from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl, C1-15
5 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from
Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof.
X is independently selected from Cl, Br, I, SCN, or NCS.
[0012] In yet another aspect of the present disclosure, there is provided a device
comprising: a) two conductive films; and b) an active layer comprising a first
10 surface and an opposing surface, interposed between the two conductive films,
wherein the active layer comprises at least one compound selected from a group
consisting of the compound of Formula I as disclosed herein, the compound of
Formula II as disclosed herein, a compound of Formula III, and a compound of
Formula Ia, its salts, stereoisomers, or solvates thereof,
15
Formula III Formula Ia
5
wherein M3 and M4 are independently selected from Ru, Os, Rh, Cr, Fe, Co, Mn, Ni, Ir, or Zn; Y and Y’ are independently selected from -CH-, -C(C1-10 alkyl)-, or N; X2, X2’, X3 and X3’ are independently selected from Cl, Br, I, SCN, or NCS; Ar is selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected 5 from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof; R” is selected from -NC-CH3, H2O, or -NC-C6-15 aryl; R3 and R4 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, 10 or combinations thereof; and refers to presence or absence of a bond.
[0013] In yet another aspect of the present disclosure, there is provided a process for preparation of the device as disclosed herein, the process comprising: a) laminating an active layer on a bottom film with the opposing surface of the active 15 layer in contact with the bottom electrode; and b) depositing a top film on the first surface of the active layer to obtain the device.
[0014] In still another aspect of the present disclosure, there is provided a use of the compound as disclosed herein, or the device as disclosed herein, in electronic devices and electrical appliances. 20
[0015] These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope 25 of the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016]
The following drawings form a part of the present specification and are included to further illustrate aspects of the present disclosure. The disclosure may 30 6
be better understood by reference to the drawings in combination with the detailed description of the specific embodiments presented herein.
[0017] Figure 1 depicts the schematic representation of the device, in accordance with an embodiment of the present disclosure.
[0018] Figure 2 depicts the plot of (A) relative permittivity of compound 1, and (B) 5 Q-V plot of the compound 1, in accordance with an embodiment of the present disclosure.
[0019] Figure 3 depicts the (A) capacitive memory data of compound 2, and (B) Q-V plot of compound 2, in accordance with an embodiment of the present disclosure.
[0020] Figure 4 depicts the cyclic voltammetric plots of (A) compound 3 and (B) 10 compound 4, in accordance with an embodiment of the present disclosure.
[0021] Figure 5 depicts the Q-V plot of the device, in accordance with an embodiment of the present disclosure.
[0022] Figure 6 depicts the Q-V plot obtained from this second device configuration in accordance with an embodiment of the present disclosure. 15
[0023] Figure 7 depicts supplementary switching data for the compound 3 in accordance with an embodiment of the present disclosure
DESCRIPTION OF THE INVENTION
[0024]
Those skilled in the art will be aware that the present disclosure is subject to variations and modifications other than those specifically described. It is 20 to be understood that the present disclosure includes all such variations and modifications. The disclosure also includes all such steps, features, compositions, and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any or more of such steps or features.
Definitions 25
[0025]
For convenience, before further description of the present disclosure, certain terms employed in the specification, and examples are delineated here. These definitions should be read in the light of the remainder of the disclosure and understood as by a person of skill in the art. The terms used herein have the meanings recognized and known to those of skill in the art, however, for 30 7
convenience and completeness, particular terms and their meanings are set forth below.
[0026]
The articles “a”, “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.
[0027]
The terms “comprise” and “comprising” are used in the inclusive, open 5 sense, meaning that additional elements may be included. It is not intended to be construed as “consists of only”. Throughout this specification, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated element or step or group of elements, or steps but not the exclusion of any other element or step or 10 group of element or steps.
[0028]
The term “including” is used to mean “including but not limited to”. “Including” and “including but not limited to” are used interchangeably.
[0029]
In the structural formulae given herein and throughout the present disclosure, the following terms have been indicated meaning, unless specifically 15 stated otherwise.
[0030] The term “alkyl” refers to a saturated hydrocarbon chain having the specified number of carbon atoms. For example, which are not limited, C1-10 alkyl refers to an alkyl group having from 1–10 carbon atoms. Alkyl groups may be straight or branched chained groups which may be optionally substituted. 20 Representative branched alkyl groups have one, two, or three branches. Preferred alkyl groups include, without limitation, methyl, ethyl, n-propyl, and isopropyl, butyl, isobutyl and t-butyl.
[0031] The term “alkoxy” refers to an alkyl group attached to a molecule via an oxygen atom. For example, which are not limited, C1-10 alkoxy refers to an alkyl 25 group having from 1–10 carbon atoms attached to an oxygen atom. Alkyl groups may be straight or branched chained groups which may be optionally substituted. Preferred alkoxy groups include, without limitation, methoxy, ethoxy, n-propoxy, and isopropoxy, butoxy, isobutoxy and t-butoxy.
[0032] The term “haloalkyl” refers to an alkyl group wherein one or more hydrogen 30 atoms are substituted with at a halogen atom. For example, which are not limited, 8
C1-10 haloalkyl refers to an alkyl group having from 1–10 carbon atoms having at least one halogen atom substituted at its hydrogen position. Alkyl groups may be straight or branched chained groups which may be optionally substituted. Preferred haloalkyl groups include, without limitation, fluoromethyl, difluoromethyl, trifluoromethyl, dichloromethyl, dichloroethyl, and the like. 5
[0033] The term “redox states” refers to the number of electrons an atom tends to lose, gain, or appear to use when combining with other atoms in compounds. In an aspect of the present disclosure, the compounds of the present disclosure have at least two redox states.
[0034] The term “capacitive states” refers to the amount of charge the material is 10 capable of holding while applied with a voltage window. In an aspect of the present disclosure, the compounds as disclosed herein exhibits one or more nonvolatile resistive states, or capacitive states which are stabilized by dipole interactions in the molecular structures of the compound.
[0035] The term “aryl” refers to aromatic systems having 6 to 15 carbon atoms, 15 which may be optionally substituted by one or more substituents. The aryl may be monocyclic, bicyclic or polycyclic and may be fused, bridged or spirocyclic rings. The aryl groups may be optionally substituted. Preferred aryl groups include, but not limited to phenyl, naphthyl and the like.
[0036] The term “heteroaryl” refers to an aryl ring system as defined above having 20 a heteroatom in the ring. The heteroaryl ring system may be attached to the main structure at any heteroatom or carbon atom resulting in the creation of a stable structure. The term “C1-15 heteroaryl” refers to an aromatic ring with one or more hetero atoms selected from N, O or S with carbon atoms ranging between 1 to 15.
[0037] The term “heterocyclyl” refers to a heterocyclic ring system that may be 25 optionally substituted by one or more substituents. The heterocyclyl ring system may be attached to the main structure at any heteroatom or carbon atom resulting in the creation of a stable structure. Furthermore, the term “C1-15 heterocyclyl” refers to a stable 1 to 15 membered ring system, which consists of carbon atoms and heteroatoms selected from nitrogen, phosphorus, oxygen and sulphur. For 30 purposes of this disclosure, the heterocyclic ring system may be monocyclic, 9
bicyclic or tricyclic ring systems, fused, bridged or spirocyclic rings, and the nitrogen, phosphorus, oxygen or sulphur atoms in the heterocyclic ring system, may be optionally oxidized to various oxidation states. The heterocyclic rings further include heteroaryl rings which are aromatic heterocyclic rings. In addition, the nitrogen atom may be optionally quaternized; and the ring system, may be partially 5 or fully saturated. The term “heterocyclyl” refers to monocyclic or polycyclic ring, polycyclic ring system refers to a ring system containing 2 or more rings, preferably bicyclic or tricyclic rings, in which rings can be fused, bridged or spirocyclic rings or any combinations thereof. A fused ring as used herein means that the two rings are linked to each other through two adjacent ring atoms common to both rings. The 10 fused ring can contain 1-4 hetero atoms independently selected from N, O, or S. The rings can be either fused by nitrogen, -CH- or -C- group.
[0038] The term "transition group metal" as used herein refers to elements in the d-block of the periodic table, including but not limited to Cr, Mn, Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Os, Ir, Pt, and other metals having partially filled d-orbitals that can 15 participate in coordination bonding.
[0039] The term “permittivity” refers to a measure of the electric polarizability of a dielectric material. A material with high permittivity polarizes more in response to an applied electric field than a material with low permittivity, thereby storing more energy in the material. In an aspect of the present disclosure, the active layer 20 has a relative permittivity in a range of 4 to 10 units depending on the applied voltage.
[0040] The term “switching time” refers to the time it takes for a sensor’s output signal to transition from a lower level to a higher level (rise time) or from a higher level to a lower level (fall time), typically measured in nanoseconds 25 (ns) or microseconds (µs). In an aspect of the present disclosure, there is provided a switching time in a range of 1 to 1 × 106 ns, in a voltage range in a range of -5 to 5V.
[0041] The term "active layer" as used herein refers to the functional layer in the device that comprises the metallic compounds and is responsible for the memory 30 10
and switching properties of the device. The active layer is interposed between two conductive films and has a first surface and an opposing surface.
[0042] The term "conductive films" as used herein refers to electrically conductive layers that serve as electrodes in the device structure. These films may be selected from materials such as indium tin oxide (ITO), fluorine doped tin oxide (FTO), 5 chromium, titanium, titanium nitride, platinum, gold, tungsten, nickel, or graphite.
[0043] The term "nonvolatile" as used herein refers to the ability of the device or compound to retain its state or stored information even when power is removed from the system.
[0044] The term "memristor" as used herein refers to a memory resistor, which is a 10 passive two-terminal electronic component that relates electric charge and magnetic flux linkage and can be used as a memory device.
[0045] The term "neuromorphic computing" as used herein refers to computing systems that mimic the neural structure and functioning of the human brain, often employing devices like memristors to create energy-efficient and scalable systems 15 capable of complex tasks such as pattern recognition and learning.
[0046] The term "device" as used herein refers to a multilayered electronic structure specifically designed for memory storage, neuromorphic computing, and analog processing applications. The device comprises a sandwich-type architecture consisting of at least three essential components arranged in a stacked 20 configuration: (a) two conductive films functioning as electrodes, and (b) an active layer interposed between the two conductive films. The active layer comprises a first surface and an opposing surface, with the first surface in contact with one conductive film and the opposing surface in contact with the other conductive film, creating a capacitive structure capable of storing and processing data through 25 voltage-controlled capacitive states rather than traditional resistive switching mechanisms. The active layer contains at least one metallic compound selected from compounds of Formula I, Formula II, Formula III, or Formula Ia, including their salts, stereoisomers, or solvates, which serve as the functional material responsible for the device's memory and switching properties. These metallic 30 compounds exhibit multiple redox states and are capable of undergoing controlled
11
molecular polarization changes in response to applied electric fields, thereby enabling the formation of multiple stable, non-volatile capacitive states that are stabilized by dipole-dipole interactions within the molecular structures. The two conductive films, which may be designated as top and bottom films, are independently selected from electrically conductive materials including but not 5 limited to indium tin oxide (ITO), fluorine doped tin oxide (FTO), chromium, titanium, titanium nitride, platinum, gold, tungsten, nickel, graphite, or multilayer stacks such as Cr/Au, Ti/Au, Ti/TiN, or Ti/TiN/Al/Ti/TiN. These conductive films have thicknesses typically ranging from 5 to 80 nm and serve as electrodes for applying voltage across the active layer and measuring the resulting charge 10 response. The device may further comprise a substrate selected from materials such as yttria stabilized zirconia (YSZ), hafnium oxide, silicon, silicon oxide, silicon nitride, or sapphire, which provides mechanical support and electrical isolation for the device structure. Additionally, the device may incorporate metal nanoparticles selected from gold, silver, platinum, tungsten, or chromium, with particle diameters 15 ranging from approximately 10 to 200 nm and thicknesses from 10 to 60 nm, which enhance the electrical contact and performance characteristics. The active layer exhibits specific dimensional and electrical characteristics, including a thickness in the range of 10 to 100 nm, a root mean square roughness in the range of 0.1 to 4 nm, and a relative permittivity in the range of 4 to 10 units depending on the applied 20 voltage. The device demonstrates switching times in the range of 1 to 1 × 106 nanoseconds within a voltage range of -5 to 5V, and exhibits sensitivity to electrical voltages in the range of -5 to 5V and optionally to electromagnetic radiation having wavelengths in the range of 200 to 1000 nm. The device operates as a memristor or memcapacitor, storing information in the form of different capacitive states that can 25 be accessed, modified, and retained without continuous power supply, making it suitable for non-volatile memory applications. The device is particularly adapted for use in neuromorphic computing systems, analog processing units, artificial intelligence hardware, dot product engines, vector matrix multiplication accelerators, and other advanced computing applications where energy efficiency, 30 high precision, and multiple stable states are required. The device architecture 12
enables write-read-erase-read (WRER) cycle operations with high durability, maintaining stable performance over extended periods and multiple switching cycles, typically up to 108 cycles or more.
[0047] Unless otherwise substituted, the valency of an atom such as carbon or nitrogen in the compounds of the present disclosure is understood to satisfy by the 5 presence of hydrogen atoms.
[0048] The compounds described herein can also be prepared in any solid or liquid physical form, for example the compound can be in a crystalline form, in amorphous form and have any particle size. Furthermore, the compound particles may be micronized or nanonized, or may be agglomerated, particulate granules, 10 powders, oils, oily suspensions, or any other form of solid or liquid physical forms.
[0049] Ratios, concentrations, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include 15 all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited.
[0050] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or 20 equivalent to those described herein can be used in the practice or testing of the disclosure, the preferred methods, and materials are now described.
[0051] As discussed in the background, there is a need in the art to develop metallic compounds with multiple redox states, better relative permittivity and having non-volatile stabilised capacitive states in order to be used in thin-film devices with 25 memristive and electrical switching properties. Further, there is a dire need to develop metallic compounds which enable functional scaling of logic and memory circuits. Owing to its diverse chemical and physical properties, organic radicals are employed in memory devices. However, high reactivity, and isolation occurring in the crystalline state are the major challenges of using such organic radicals in such 30 devices. In this view, utilizing transition-metal ions with multiple oxidation states
13
to obtain metallic compounds with organic ligands is an advantageous technique to achieve efficient memory devices, wherein these metal ions act as a carrier of these radical ligands. Such metallic compounds are then advantageously used in memristor devices.
[0052] In the context of modern computing systems, it may be noted that such 5 computing systems have evolved over the years, transitioning from analog to digital and now, the emergence of artificial intelligence (AI) has led to increasing interest in the application of analog systems. As may be understood, analog computing systems are known for their ability to process continuous data, which is particularly useful in AI applications, such as neural networks and signal processing. These 10 systems operate by manipulating continuous electrical signals to perform computations, unlike digital systems that process discrete binary data.
[0053] Analog computing may be efficiently realized by memory devices (interchangeably referred to as memristors) as a described in the present disclosure. As may be generally understood, memristors are known for their ability to retain 15 information, even in the absence of power, making them ideal for non-volatile memory applications.
[0054] The above described memory devices may be used in neuromorphic computing. Neuromorphic computing seeks to mimic the neural structure of the human brain to create energy-efficient and scalable systems capable of complex 20 tasks. Neuromorphic systems often employ memristors as synaptic weights in artificial neural networks due to their ability to store multiple states, thereby enabling the representation of synaptic weights with high precision.
[0055] Vector matrix multiplication (VMM) is a common operation in many computing algorithms, including those used in AI and machine learning. However, 25 the implementation of VMM in traditional digital computing systems can be time and energy-intensive due to the large number of computational steps involved. To address this, dot-product engines (DPEs) have been developed as a type of analog accelerator that can perform VMM in a single time-step, thereby increasing computational efficiency. 30 14
[0056] Dot product engines are analog neuromorphic accelerators that facilitates vector-matrix multiplication with far more energy, space and time efficiency as compared to digital platforms. Despite the technical advantages that such devices provide, the main difficulty lies in achieving analog precision in such memory devices. Existing neuromorphic devices (e.g. metal oxide or 2D or phase change 5 materials) only offer 2–6-bit analog precision which restricts the application of neuromorphic platforms for defined computation problems. Such devices however cannot be efficiently used for core computing operations in neural network training, signal and image processing. This limitation arises, amongst other factors, due to stochastic ion diffusion and filamentary mechanism. 10
[0057] Furthermore, as described previously, the conventionally employed memory devices exploit compounds that exhibit limited capacitive states and rely on resistive properties. This poses another challenge in conventionally available memory switching devices which store data as conductance levels. As a result, any operations would entail drawing higher currents in instances when conductance 15 levels are high. This in turn may lead to higher dissipative losses thus resulting into inefficiencies
[0058] The current redox active organic ligands that are used for realizing the memory devices overcome the above mentioned technical problems and provide a number of technical advantages. The current devices store data in the form of 20 capacitive values. Since the devices store and process data though capacitive states with voltage being the input and charge being the output, data processing may be performed without drawing high current and thus would result in a highly energy efficient accelerator.
[0059] Accordingly, the present disclosure provides a compound comprising redox 25 active organic ligands which has at least two redox states and are capable of possessing multiple non-volatile capacitive states. The present disclosure employs active layers made of transition metal-organic complexes wherein the organic ligands are majorly azo-based aromatic ligands. The active layer having appropriate relative permittivity is placed between two electrodes that facilitate in can charge 30 storing and computing using non-volatile capacitance states. 15
[0060] The present disclosure provides heteroleptic complexes, wherein bidentate redox active organic ligands are coordinated to a metal ion along with multiple halide ligands. As a function of an electric field, the metal-halide bonds can undergo elongation and contraction resulting in substantial change in the polarization of the molecules causing changes in film permittivity and thus the capacitance states. The 5 present disclosure employs second and third row transition metal ions in these complexes because these complexes can then exist in multiple geometric isomers. Each of the isomers would then possess different effects in the electrostatic surface potential of the molecule as a function of electric field. Different metal centres of different isomers/compounds can facilitate different molecular geometries, 10 electrical polarization and electrostatic surface potential affecting their capacitive states. The present disclosure employs azo-based aromatic moieties as ligands which can substantially vary the polarization in the molecule affecting the capacitive states that the device can store. When the polarization is varied, the molecules interact differently with each other resulting in additional relaxation 15 energies due to dipole interactions. These dipole interactions may stabilize different non-volatile capacitive states depending on the molecular structures.
[0061] Accordingly, the present disclosure provides a compound of Formula I
Formula I 20
wherein X1 and X1’ are independently selected from Cl, Br, I, NCS, SCN, or N3; M1 is selected from Cr, Mn, Fe, Co, Ni, Os, Pt, Pd, Ru, Rh, or Ir; R’ is absent or is selected from -NC-C1-10 alkyl, or -NC-C6-15 aryl; R1 and R2 are independently
16
selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof; and refers to presence or absence of a bond.
[0062] In an embodiment of the present disclosure, there is provided a compound 5 of Formula II
Formula II wherein M2 is a transition group metal; and Ar1 and Ar2 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl, C1-15 10 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof.
[0063] In another embodiment of the present disclosure, there is provided a compound of Formula II as disclosed herein, wherein M2 is a transition group metal; and Ar1 and Ar2 are independently selected from C6-12 aryl, C1-12 heteroaryl, or C1-15 12 heterocyclyl, wherein the C6-12 aryl, C1-12 heteroaryl, or C1-12 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-5 alkyl, C1-5 alkoxy, C1-5 haloalkyl, cyano, or combinations thereof
[0064] In yet another embodiment of the present disclosure, there is provided a compound of Formula II as disclosed herein, wherein M2 is a transition group metal; 20 and Ar1 and Ar2 are independently selected from C6-10 aryl, C6-10 heteroaryl, or C6-
17
10 heterocyclyl, wherein the C6-10 aryl, C6-10 heteroaryl, or C6-10 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-3 alkyl, C1-3 alkoxy, C1-3 fluoroalkyl, C1-3 chloroalkyl, C1-3 bromoalkyl, C1-3 iodoalkyl, cyano, or combinations thereof.
[0065] In an embodiment of the present disclosure, there is provided a compound 5 of Formula I as disclosed herein, wherein R’ is absent, when refers to presence of a single bond, M1 is selected from Cr, Mn, Fe, or Co, R1 and R2 are independently C6 aryl, and X1 and X1’ are independently selected from Cl, Br, NCS, or SCN; and when refers to absence of a single bond, M1 is selected from Pt, or Pd; R1 and R2 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-10 15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof.
[0066] In an embodiment of the present disclosure, there is provided a compound of Formula I as disclosed herein, wherein R’ is absent, refers to presence of 15 a single bond, M1 is selected from Cr, Mn, Fe, or Co, R1 and R2 are C6 aryl, and X1 and X1’ are independently selected from Cl, Br, NCS, or SCN.
[0067] In an embodiment of the present disclosure, there is provided a compound of Formula I as disclosed herein, wherein R’ is absent, refers to absence of a single bond, M1 is selected from Pt, or Pd; R1 and R2 are independently selected 20 from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof.
[0068] In an embodiment of the present disclosure, there is provided a compound of Formula I as disclosed herein, wherein R’ is -NC-C1-10 alkyl, refers to 25 presence of a single bond; M1 is selected from Os, Ru, Rh, or Ir; R1 and R2 are C6 aryl; and X1 and X1’ are selected from Cl, Br or I.
[0069] In an embodiment of the present disclosure, there is provided a compound of Formula II as disclosed herein, wherein M2 is selected from Cr, Mn, Fe, Co, Ni, Zn, Ru, Rh, Os, or Ir; Ar1 and Ar2 are independently selected from C6-15 aryl, C1-15 30 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl, C1-15 heteroaryl, or C1-15
18
heterocyclyl is optionally substituted with one or more groups selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, or cyano.
[0070] In an embodiment of the present disclosure, there is provided a compound as disclosed herein, wherein the compound has at least two redox states. In another embodiment of the present disclosure, the compound has two to six redox states. 5
[0071] In an embodiment of the present disclosure, there is provided a compound as disclosed herein, wherein the compound is sensitive to an electrical voltage in a range of -5 to 5V; an electromagnetic irradiation having a wavelength in a range of 200 to 1000 nm.
[0072]
In an embodiment of the present disclosure, there is provided a compound 10 as disclosed herein, wherein the compound exhibits one or more nonvolatile resistive, capacitive states, or combinations thereof.
[0073]
In an embodiment of the present disclosure, there is provided a compound as disclosed herein, wherein the compound exhibits one or more nonvolatile resistive or capacitive states which are stabilized by dipole interactions in the 15 molecular structures of the compound.
[0074]
In an embodiment of the present disclosure, there is provided a device comprising: a) two conductive films; and b) an active layer comprising a first surface and an opposing surface, interposed between the two conductive films, wherein the active layer comprises at least one compound selected from a group 20 consisting of the compound of Formula I as disclosed herein, the compound of Formula II as disclosed herein, a compound of Formula III, and a compound of Formula Ia, its salts, stereoisomers, or solvates thereof,
Formula III Formula Ia 25 19
wherein M3 and M4 are independently selected from Ru, Os, Rh, Cr, Fe, Co, Mn, Ni, Ir, or Zn; Y and Y’ are independently selected from -CH-, -C(C1-10 alkyl)-, or N; X2, X2’, X3 and X3’ are independently selected from Cl, Br, I, SCN, or NCS; Ar is selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected 5 from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof; R” is selected from -NC-CH3, H2O, or -NC-C6-15 aryl; R3 and R4 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, 10 or combinations thereof; and refers to presence or absence of a bond.
[0075]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the compound of Formula III is selected from
15 20
wherein M is selected from Ru, Os, Rh, Ir, Cr, Fe, Mn, Co, Ni, or Zn; Y is selected from -CH-, -C(C1-10 alkyl)-, or N; Xa, Xa’, Xb, Xb’, Xc, Xc’, Xd, Xd’, Xe, Xe’, Xf, Xf’, Xg, and Xg’ are independently selected from Cl, Br, SCN, NCS, or I; and Ara, Ara’, Arb, Arb’, Arc, Arc’, Ard, Ard’, Are, Are’, Arf, Arf’, Arg, and Arg’, are independently 5 selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof.
[0076]
In an embodiment of the present disclosure, there is provided a device as 10 disclosed herein, wherein the two conductive films are a top film and a bottom film.
[0077]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the bottom film is in contact with the first surface of the active layer, and the top film is in contact with the opposing surface of the active layer. 15
[0078]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the two conductive films are selected from a top film and a bottom film and the bottom film is in contact with the first surface of the active layer, and the top film is in contact with the opposing surface of the active layer.
[0079]
In an embodiment of the present disclosure, there is provided a device as 20 disclosed herein, wherein the active layer is coated on the bottom film.
[0080]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the device further comprises a substrate selected from
21
yttria stabilized zirconia (YSZ), hafnium oxide, silicon, silicon oxide, silicon nitride, or sapphire. In another embodiment of the present disclosure, the substrate is yttria stabilized zirconia (YSZ).
[0081]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the device further comprises metal nanoparticles selected 5 from gold, silver, platinum, tungsten, or chromium.
[0082]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the metal nanoparticles is gold. In another embodiment of the present disclosure, wherein the metal nanoparticles is Platinum.
[0083]
In an embodiment of the present disclosure, there is provided a device as 10 disclosed herein, wherein the metal nanoparticles is gold having an average particle diameter in the range of 10-200 nm, with a corresponding thickness ranging from 10 to 60 nanometers. This size distribution contributes to enhanced interfacial properties and improved charge transport within the device architecture.
[0084]
In an embodiment of the present disclosure, there is provided a device as 15 disclosed herein, wherein the active layer, the top film and the bottom film are arranged in series.
[0085]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the two conductive films are independently selected from indium tin oxide (ITO), fluorine doped tin oxide (FTO), chromium, titanium, 20 titanium nitride, platinum, gold, tungsten, nickel, or graphite. Conductive films other than indium tin oxide (ITO) may also be employed, including multilayer stacks such as Cr/Au, Ti/Au, Ti/TiN, and Ti/TiN/Al/Ti/TiN, depending on the desired electrical, optical, and structural properties of the device.
[0086]
In an embodiment of the present disclosure, there is provided a device as 25 disclosed herein, wherein the active layer has a relative permittivity in a range of 4 to 10 units depending on the applied voltage.
[0087]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the active layer has a thickness in a range of 10 to 100nm; and the top film and the bottom film independently have a thickness in a range of 5 30 to 80 nm. 22
[0088]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the active layer has a root mean square roughness in a range of 0.1 to 4 nm.
[0089]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the device exhibits a switching time in a range of 1 to 1 5 × 106 ns, in a voltage range of -5 to 5V.
[0090]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the device is sensitive to an electrical voltage in a range of -5 to 5V; an electromagnetic radiation having a wavelength in a range of 200 to 1000 nm. 10
[0091]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the active layer is configured to undergo capacitive switching, resistive switching, or a combination thereof, the switching being operable in digital mode with sharp capacitance or conductance transitions or in analog mode with gradual capacitance or conductance modulation depending on 15 the applied stimulus.
[0092]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the capacitive switching mode provides retention of distinct charge states for months without applied voltage, indicative of the stability of the underlying electronic states of the active material, that could also be used for 20 resistive switching mode as well.
[0093]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the device demonstrates endurance sufficient to withstand at least 10? switching cycles without substantial degradation of performance, while maintaining stable capacitive and/or resistive switching characteristics. 25
[0094]
In an embodiment of the present disclosure, there is provided a device as disclosed herein, wherein the device exhibits long-term operational stability under ambient conditions, maintaining switching performance over extended durations without significant loss of functionality
[0095]
In an embodiment of the present disclosure, there is provided a process for 30 preparation of the device as disclosed herein, the process comprising: a) laminating
23
an active layer on a bottom film with the opposing surface of the active layer in contact with the bottom electrode; and b) depositing a top film on the first surface of the active layer to obtain the device.
[0096]
In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the bottom film and top film are obtained by deposition 5 methods independently selected from a vacuum vapor deposition method, cluster ion beam method, pulsed laser deposition (PLD) method, chemical vapor deposition (CVD) method, plasma polymerization method, molecular beam epitaxy (MBE) method, thermal/ electron beam evaporation or sputtering method. In another embodiment of the present disclosure, the the bottom film and top film are 10 obtained by pulsed laser deposition (PLD) method, thermal/ electron beam evaporation or sputtering method. In another embodiment of the present disclosure, the the bottom film and top film are obtained by pulsed laser deposition (PLD) method.
[0097]
In an embodiment of the present disclosure, there is provided a process as 15 disclosed herein, wherein laminating the active layer is carried out by coating a solution comprising a solvent and at least one compound of Formula I, Formula II, Formula III or Formula Ia, upon the bottom film.
[0098]
In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the solvent is selected from CH3CN, dimethyl formamide 20 (DMF), dichloromethane (CH2Cl2), dichloroethane (ClCH2CH2Cl), chloroform (CH3Cl), methanol (CH3OH), ethanol (C2H5OH), or combinations thereof.
[0099]
In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the coating is carried out by spin coating, jet printing, sol-gel coating, drying, or combinations thereof. In another embodiment of the present 25 disclosure, the coating is carried out by spin coating and drying.
[00100]
In an embodiment of the present disclosure, there is provided a process as disclosed herein, wherein the coating is carried out by spin coating at a speed in a range of 1000 to 12000 rpm, for a period in a range of 20 to 120 seconds.
[00101]
In an embodiment of the present disclosure, there is provided a use 30 of the compound as disclosed herein, or the device as disclosed herein. 24
[00102]
In an embodiment of the present disclosure, there is provided a use of the compound as disclosed herein, or the device as disclosed herein, in electronic devices and electrical sensory and computing appliances.
[00103] Although the subject matter has been described in considerable detail with reference to certain examples and implementations thereof, other implementations 5 are possible.
EXAMPLES
[00104] The disclosure will now be illustrated with working examples, which is intended to illustrate the working of disclosure and not intended to take restrictively 10 to imply any limitations on the scope of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice of the disclosed methods, the exemplary methods, 15 devices and materials are described herein. It is to be understood that this disclosure is not limited to particular methods, and experimental conditions described, as such methods and conditions may apply. EXAMPLE 1 Preparation of compounds 20 General procedure for the preparation of Compound of Formula I
[00105] For the purpose of the present disclosure, the below compounds were prepared for the compound of Formula I. The compounds were prepared as described below. 2,6-bis(phenylazo)pyridine was refluxed with equivalent amount of metal(II) halide/pseudohalide (X) in methanol for 4h. The resultant solution was 25 evaporated to dryness and washed with hexane to yield crude product which upon crystallization from dichloromethane-hexane mixture (1:1) yielded pure compound M(2,6-bis(phenylazo)pyridine)X2. Preparation of Compound 1 ([Co(2,6-bis(phenylazo)pyridine)Cl2]): 25
[00106] 2,6-bis(phenylazo)pyridine was refluxed with equivalent amount of cobalt(II) chloride in methanol solvent for 4 hours. Subsequently, the resulting mixture was subjected to evaporation to remove the solvent and the obtained residue was washed using hexane to obtain the compound 1. Preparation of Compound 2 ([Co(2,6-bis(phenylazo)pyridine)Br2]): 5
[00107] 2,6-bis(phenylazo)pyridine was refluxed with equivalent amount of cobalt(II) bromide in methanol solvent for 4 hours. Subsequently the resulting mixture was subjected to evaporation to remove the solvent, yielded crude product which upon crystallization from dichloromethane-hexane (1:1) yielded pure compound 2. 10 Preparation of Compound 3 ([Co(2,6-bis(phenylazo)pyridine)(NCS)2]): 2,6-bis(phenylazo)pyridine was refluxed with equivalent amount of cobalt(II) isothiocyanate in methanol solvent for 4 hours. The resultant solution was evaporated to dryness and washed with hexane yielded crude product which upon crystallization from dichloromethane-hexane mixture (1:1) yielded pure compound 15 3.
[00108] Table 1: Compounds of Formula I
Compound
Structure
Characterization
Compound 1
26
Compound
2
Compound
3
Compound
4
27
Compound
5
Compound
6
General process of preparation of the Compound of Formula II
[00109] For the purpose of the present disclosure, the below compounds
were prepared as representative examples to Compound of Formula II.
28
Formula II
Compound Strcuture Characterization
Compound 7
Compound 8
Compound 9
29
Compound
10
Process of preparation for Compound 8 ([Co(2-(phenylazo)pyridine)2Br2])
[00110] 2-(phenylazo)pyridine was refluxed with cobalt(II) bromide in 2:1
molar ratio in methanol solvent for 4 hwours. Subsequently, the resulting mixture
5 was subjected to evaporation to remove the solvent, and the obtained residue was
washed using hexane to obtain the compound 8.
General process for the preparation of Compound of Formula III
[00111] Reaction between MX2 and 2 equiv of iminopyridines in THF at
room temperature afforded metal(II)(iminopyrdinine)2X2 complexes in high yields.
10 [00112]
Formula III
Table 3: Representative compounds of Formula III
Compound Structure Characterization (X-ray
structure)
30
Compound
11
(Formula
III)
Compound
12
(Formula
III)
Compound
13
(Formula
Ia)
Compound
14
(Formula
Ia)
31
Compound
15
(Formula
Ia)
Compound
16
(Formula
Ia)
32
Compound
17(Formula
III d)
Compound
18
(Formula
III b)
1H NMR (1H NMR (CD3CN, 300
MHz): d 9.27 (d, J = 6 Hz, 1H), 8.41
(d, J = 8 Hz, 1H), 7.88 (t, J = 8.2
Hz, 1H), 7.42 (t, J = 6 Hz, 1H), 7.17
(t, J = 7 Hz, 1H), 7.01 (t, J = 8.5 Hz,
2H), 6.72 (d, J = 7.3 Hz, 1H) ppm
EXAMPLE 2
Preparation of device
5 [00113] General process for the preparation of device: The device was
fabricated following a multi-step process comprising substrate preparation, bottom
electrode deposition, active layer coating, vacuum treatment, gold nanoparticle
deposition, and top electrode deposition. Specifically, yttria-stabilized zirconia
(YSZ) substrates were annealed to enhance surface uniformity, followed by
10 deposition of indium tin oxide (ITO) as the bottom electrode using pulsed laser
deposition (PLD). The active organic layer was applied via spin coating of
compound (of the present disclosure) solutions, with concentrations ranging from
5 mM to 50 mM, resulting in film thicknesses between 5 nm and 50 nm,
respectively. This established a direct correlation between solution concentration
15 and film thickness. Post-coating, the device underwent vacuum treatment to remove
residual solvents and improve film integrity. Gold nanoparticles were then
deposited to enhance charge transport and interfacial properties. Finally, a top ITO
electrode was deposited using PLD to complete the device architecture. This
33
process flow enabled precise control over layer thickness and composition, contributing to the device’s enhanced performance characteristics.
[00114] Using the process described above, devices can be fabricated employing any of the compounds 1 through 19 disclosed in the present invention. Each compound may be formulated into a solution with a concentration ranging 5 from 5 mM to 50 mM, which directly influences the thickness of the resulting active organic layer, typically ranging from 5 nm to 50 nm. The fabrication process involves sequential steps including substrate preparation through annealing of yttria-stabilized zirconia (YSZ), deposition of the bottom electrode using indium tin oxide (ITO) via pulsed laser deposition (PLD), spin coating of the compound 10 solution to form the active layer, vacuum treatment to enhance film integrity, deposition of gold nanoparticles to improve interfacial properties, and final deposition of the top ITO electrode via PLD. The compounds 1–19, which may exist as salts, stereoisomers, solvates, or combinations thereof, are suitable for forming the active layer due to their redox-active properties and responsiveness to 15 external stimuli such as voltage, light, and pH.
[00115] Stock solutions for each of compounds 1, 2, 3, and 7 were prepared in CH3CN or DMF with concentrations ranging from 5-50 mM, which provided active layer thicknesses in the range of 5-50 nm respectively.
[00116] Indium tin oxide (ITO; bottom conductive film) was grown on an 20 annealed yttria-stabilized zirconia (YSZ; substrate) via pulsed laser deposition technique and the thickness of the bottom film was found to be in a range of 5 to 80 nm.
[00117] The stock solution of the appropriate compound was filtered through a 0.2 µm syringe filter and subsequently spin-coated onto the bottom conductive 25 film ITO surface at a speed of 3000 rpm, for 2 minutes to obtain an active layer having root mean square roughness in a range of 0.3 to 4 nm and thickness of 10 to 50 nm coated on the bottom conductive film.
[00118] After coating, the samples were stored in a vacuum chamber with a pressure of ~10-8 torr for 12 h. Further, gold nanoparticles were deposited on the 30 ITO bottom conductive film, using electron beam evaporation. Subsequently, a top 34
conductive film of ITO was assembled by pulsed laser deposition (PLD) method upon the active layer.
[00119] Figure 1 depicted the general representation of the device (100), comprising: a top conductive film as described herein selected from ITO, fluorine doped tin oxide (FTO), chromium, titanium, titanium nitride, platinum, gold, 5 tungsten, nickel, or graphite (101); a bottom conductive film as described herein selected from ITO, fluorine doped tin oxide (FTO), chromium, titanium, titanium nitride, platinum, gold, tungsten, nickel, or graphite (102); an active layer (103) comprising a first surface (103a) and an opposing surface (103b); and a substrate (YSZ;104). The device structure demonstrates the sandwich configuration with the 10 active layer interposed between the two conductive films. EXAMPLE 3 Analysis of the compounds and Device Performance Relative permittivity measurement 15
[00120] The relative permittivity of the compound 1 was analysed in comparison to other salts and forms of similar compounds, as shown in Figure 2(A). The compound 1 is denoted as Co(L)Cl2, where L represents 2,6-bis(phenylazo)pyridine. The compounds Co(L2)(PF6)2 and Co[(L)(L•-)](PF6) refers to hexafluoro phosphate (PF6) salts of the cobalt based compound 1, wherein L is 20 2,6-bis(phenylazo)pyridine, L•- is one electron reduced 2,6-bis(phenylazo)pyridine. The relative permittivity measurements demonstrated that compound 1 exhibited enhanced permittivity values reaching approximately 8-9 units at specific voltage ranges, significantly higher than the comparison compounds. The chemical structures of the compounds Co(L2)(PF6)2 and Co[(L)(L.-)](PF6) are provided 25 below. 35
Figure 2(B) shows the Q-V (charge-voltage) plot of compound 1, which displayed characteristic hysteretic behavior with distinct capacitive states. The hysteresis loop demonstrated the non-volatile nature of the capacitive states, with the device maintaining different charge levels at the same voltage depending on the sweep 5 direction. Capacitive memory measurement
[00121] The capacitive memory exhibited by the compound 2 was observed to be enhanced, as demonstrated in Figure 3(A) and (B).
[00122] Figure 3(A) shows the capacitive memory data of compound 2, 10 displaying multiple stable capacitive states across the voltage range of -5V to +5V. The plot revealed distinct capacitance levels that could be accessed and maintained, demonstrating the multi-state memory capability of the device.
[00123] Figure 3(B) presents the Q-V plot of compound 2, which exhibited pronounced hysteretic behavior with an area under the curve of 2.67 × 10-11 C, 15 indicating substantial charge storage capability and stable switching between different capacitive states. Cyclic voltametric measurement:
[00124] Cyclic voltammetric (CV) experiments of the compounds 3 and 8, 20 were carried out in dried acetonitrile using tetraethylammonium hexafluorophosphate as the supporting electrolyte.
Co(L2)(PF6)2Co[(L)(L.-)](PF6)
36
[00125] All electrochemical measurements were performed using a CH electrochemical instrument (model number: CHI620E), keeping the CV-cell assembly inside a glove box maintained at an oxygen level and a moisture level each of less than 1 ppm. A three-electrode cell was used for the CV measurements where the working electrode was glassy carbon (area = 3.14 mm2) coated with the 5 compound 3 or 7, the reference electrode was saturated calomel electrode (SCE), the electrolyte was acetonitrile containing 0.1 M [Et4N]PF6 and the counter electrode was a Pt-wire (area = 220.69 mm2) dipped in a glass compartment having solution of 0.1 M [Et4N]PF6 in acetonitrile.
[00126] Figure 4 (A) shows the CV plot for compound 3, having multiple 10 reduction and oxidation peaks demonstrating the presence of multiple accessible redox states within the voltage window examined. The cyclic voltammogram revealed at least three distinct redox processes, indicating the compound's ability to exist in multiple stable oxidation states. Figure 4 (B) shows the CV plot of compound 8, having 2 well-resolved reduction peaks, confirming the presence of at 15 least two distinct redox states. The electrochemical analysis confirmed that compounds 3 and 8 were promising candidates for memory applications, as different redox states of these compounds offered different intermolecular coupling resulting in differences in conductance and hence electrical switching. EXAMPLE 4 20
Device Performance Characterization
Switching Behavior and Conductance Variation
[00127] The electrical switching behavior of the device prepared according to Example 2 was characterized using charge-voltage (Q-V) measurements. The device comprised compound 7 ([Co(PAP)2Cl2]) as the active material in a sandwich 25 structure between ITO conductive films on a YSZ substrate.
[00128] Figure 5 presented the Q-V plot obtained from this device configuration, which demonstrated distinctive hysteretic loop behavior characteristic of capacitive memory operation. The measurement was conducted by
37
applying a voltage sweep from -4V to +4V and recording the corresponding charge response. The hysteresis loop exhibited two distinct branches, indicating that the device maintained different charge states at the same voltage depending on the sweep direction.
[00129] The device as claimed, wherein the operational voltage range 5 required to induce charge storage or switching behaviour is reducible (down to 1V) through molecular design and electrode–interface engineering, and wherein, in addition to charge–voltage [Q(V)] characteristics, current–voltage [I(V)] responses are tunable based on the choice of ligands and molecular structure of the active material. 10
[00130] The area under the curve was calculated to be 6.65 × 10-11 C, which represented substantial charge storage capability and confirmed the device's ability to function as a high-capacity memory element. The hysteretic behavior was attributed to the controlled elongation and contraction of Co-Cl bonds in response to the applied electric field, resulting in significant changes in molecular 15 polarization that directly affected the permittivity of the active layer.
[00131] The voltage range of the measurement (-4V to +4V) was well within the claimed sensitivity range of -5 to 5V, demonstrating the device's operational compatibility with standard electronic systems. The smooth, well-defined hysteresis loop indicated stable switching behavior without erratic fluctuations or 20 breakdown phenomena, confirming the robustness of the metallic compound under electrical stress.
[00132] A second device was prepared using identical fabrication procedures as described in Example 2, employing compound 8 ([Co(PAP)2Br2]) as the active material. This device was subjected to similar Q-V characterization to evaluate the 25 reproducibility of the switching behavior and assess the influence of different halide ligands on device performance.
[00133] Figure 6 displayed the Q-V plot obtained from this second device configuration, which exhibited similar hysteretic characteristics to the first device but with quantitatively different parameters. The hysteresis loop maintained the 30 characteristic shape and voltage range, confirming the consistency of the switching
38
mechanism across different compound compositions within the Formula I framework.
[00134] The area under the curve for this device was measured to be 2.67 × 10-11 C, which, while smaller than the first device, still represented significant charge storage capability. The difference in area values was attributed to the 5 substitution of bromide ligands for chloride ligands, which altered the electronic properties and polarization response of the metallic compound while maintaining the fundamental switching mechanism.
[00135] The reproducible hysteretic behavior across different halide compositions demonstrated the versatility of the Formula I compounds and 10 confirmed that systematic variation of the X1 and X1' ligands (Cl, Br, I, NCS, SCN, N3) could be used to tune the device performance while maintaining reliable switching characteristics. The consistent voltage range and loop morphology provided strong evidence for the predictability and controllability of the device behavior. 15
[00136] The devices prepared with compounds 1-3 and 7 demonstrated excellent switching behavior with switching times in the range of 1 to 1 × 106 nanoseconds within a voltage range of -5 to 5V. The electrical switching behavior was characterized by measuring the charge-voltage relationships, which showed distinct hysteretic loops indicating stable switching between different capacitive 20 states. EXAMPLE 5 Extended Performance Characterization and Stability Analysis
[00137] Additional electrical characterization was performed on devices prepared with compounds 3 and 7 to demonstrate the extended scope of switching 25 behavior across different Formula I and Formula II compounds. These measurements provided comprehensive data on switching time characteristics, cycle stability, and long-term performance reliability.
[00138] Figure 7 presented supplementary switching data for the compound 3 that included multiple consecutive Q-V measurements performed on the same 30 device to assess cycle-to-cycle consistency and long-term stability. The overlaid
39
plots demonstrated that the hysteretic behavior remained stable across multiple switching cycles, with minimal drift in the loop position or area.
[00139] The switching time measurements revealed that the devices achieved switching times in the range of 1 to 1 × 106 nanoseconds within the voltage range of -5 to 5V, confirming the claimed performance specifications. The fast 5 switching response was attributed to the rapid molecular reorganization of the metallic compounds in response to applied electric fields, enabled by the flexible coordination geometry around the metal centers.
[00140] Stability testing demonstrated that the devices maintained their switching characteristics over months, with no significant degradation observed 10 after millions of switching cycles which could further be carried out until billions or even trillions of cycles. The devices showed excellent retention of their capacitive states, maintaining distinct charge levels for extended periods without applied voltage, confirming their non-volatile memory characteristics.
[00141] The retention of distinct charge states in capacitive operation is 15 indicative of the stability of the underlying electronic states of the active molecular species, and wherein in resistive memory operation obtained through ligand substitution or ionic modification, comparable non-volatile retention is exhibited in the current or conductance state.
[00142] The comprehensive electrical characterization data presented in 20 herein provided definitive experimental evidence for the superior performance of the disclosed metallic compounds compared to conventional memory materials. The results demonstrated that the compounds successfully enabled: -Multiple stable capacitive states with well-defined switching thresholds -Substantial charge storage capability quantified by significant Q-V loop 25 areas - Reproducible performance across different compound compositions and device configurations -Fast switching response suitable for high-speed memory applications - Excellent stability and retention characteristics for non-volatile memory 30 operation. 40
[00143] These experimental results validated the technical advantages claimed in the patent application and confirmed that the disclosed metal complexes successfully overcame the limitations of prior art memory devices through their unique molecular design and capacitive switching mechanism. 5 ADVANTAGES OF THE PRESENT DISCLOSURE
[00144] The present disclosure provides significant technical advantages over conventional memory devices and neuromorphic computing systems through its novel metallic compounds and device architecture. The compounds disclosed in the present disclosure possess multiple redox states and enhanced capacitive states, 10 by virtue of which the devices comprising these compounds as active compounds exhibit better and efficient switching and memory effects. The present disclosure provides heteroleptic compounds having at least two types of ligands attached to the metal ion. The compounds of the present disclosure having varying ligands undergo elongation-contraction resulting in substantial change in the polarization 15 of the molecules causing changes in active layer permittivity and thus the capacitance. The compounds affect the electrostatic surface potential of the active layer, as a function of electric field thereby varying the capacitive states.
[00145] The device disclosed in the present disclosure has an active layer interposed between two conductive films, wherein the active layer comprises the 20 compounds which would interact with each other resulting in additional relaxation energies due to dipole-dipole interactions which stabilizes different non-volatile capacitive states depending on the molecular structures. The device has an enhanced relative permittivity which leads to possess a better capacitive behaviour.
[00146]
The device is operable as both a capacitive storage element and a 25 compute element, thereby enabling in-memory computing, and wherein the device is further integrable into a crossbar array architecture to perform complex mathematical operations including, but not limited to, matrix multiplication.
[00147]
Since the devices store and process data though capacitive states with voltage being the input and charge being the output, data processing may be 30 41
performed by drawing minimal current and thus would result in a highly energy efficient accelerator. 42
I/We Claim:
1. A compound of Formula I
Formula I
wherein X1 and X1’ are independently selected from Cl, Br, I, NCS, SCN, 5 or N3; M1 is selected from Cr, Mn, Fe, Co, Ni, Os, Pt, Pd, Ru, Rh, or Ir; R’ is absent or is selected from -NC-C1-10 alkyl, or -NC-C6-15 aryl; R1 and R2 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof; and refers to presence or absence of a bond.
2.
A compound of Formula II
Formula II 15 43
wherein M2 is a transition group metal; and Ar1 and Ar2 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof. 5
3. The compound of Formula II as disclosed herein, wherein M2 is a transition group metal; and Ar1 and Ar2 are independently selected from C6-12 aryl, C1-12 heteroaryl, or C1-12 heterocyclyl, wherein the C6-12 aryl, C1-12 heteroaryl, or C1-12 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-5 alkyl, C1-5 alkoxy, C1-5 haloalkyl, cyano, or combinations thereof 10
4. The compound of Formula II as claimed in claim 2, wherein M2 is a transition group metal; and Ar1 and Ar2 are independently selected from C6-10 aryl, C6-10 heteroaryl, or C6-10 heterocyclyl, wherein the C6-10 aryl, C6-10 heteroaryl, or C6-10 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-3 alkyl, C1-3 alkoxy, C1-3 fluoroalkyl, C1-3 15 chloroalkyl, C1-3 bromoalkyl, C1-3 iodoalkyl, cyano, or combinations thereof.
5. The compound of Formula I as claimed in claim 1, wherein R’ is absent, when refers to presence of a single bond, M1 is selected from Cr, Mn, Fe, or Co, R1 and R2 are independently C6 aryl, and X1 and X1’ are 20 independently selected from Cl, Br, NCS, or SCN; and when refers to absence of a single bond, M1 is selected from Pt, or Pd; R1 and R2 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 25 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof.
6. The compound of Formula I as claimed in claim 1, wherein R’ is absent, refers to presence of a single bond, M1 is selected from Cr, Mn, Fe, or Co, R1 and R2 are C6 aryl, and X1 and X1’ are independently selected from Cl, Br, NCS, or SCN. 30 44
7. The compound of Formula I as claimed in claim 1, wherein R’ is absent, refers to absence of a single bond, M1 is selected from Pt, or Pd; R1 and R2 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 5 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof.
8. The compound of Formula I as claimed in claim 1, wherein R’ is -NC-C1-10 alkyl, refers to presence of a single bond; M1 is selected from Os, Ru, Rh, or Ir; R1 and R2 are C6 aryl; and X1 and X1’ are selected from Cl, or Br.
9. The compound of Formula II as claimed in claim 2, wherein M2 is selected 10 from Cr, Mn, Fe, Co, Ni, Zn, Ru, Rh, Os, or Ir; Ar1 and Ar2 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with one or more groups selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, or cyano. 15
10. The compound as claimed in any one of the claims 1-9, wherein the compound has at least two redox states.
11. The compound as claimed in any one of the claims 1-9, wherein the compound is sensitive to an electrical voltage in a range of -5 to 5V; an electromagnetic irradiation having a wavelength in a range of 200 to 1000 20 nm.
12. The compound as claimed in any one of the claims 1-9, wherein the compound exhibits one or more nonvolatile resistive, capacitive states, or combinations thereof.
13. The compound as claimed in any one of the claims 1-9, wherein the 25 compound exhibits one or more nonvolatile resistive or capacitive states which are stabilized by dipole interactions in the molecular structures of the compound.
14. A device comprising: a) two conductive films; and b) an active layer comprising a first surface and an opposing surface, interposed between the 30 two conductive films, wherein the active layer comprises at least one 45
compound selected from a group consisting of the compound of Formula I as claimed in claim 1, the compound of Formula II as claimed in claim 2, a compound of Formula III, and a compound of Formula Ia, its salts, stereoisomers, or solvates thereof,
5
Formula III Formula Ia
wherein M3 and M4 are independently selected from Ru, Os, Rh, Cr, Fe, Co, Mn, Ni, Ir, or Zn; Y and Y’ are independently selected from -CH-, -C(C1-10 alkyl)-, or N; X2, X2’, X3 and X3’ are independently selected from Cl, Br, I, SCN, or NCS; Ar is selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 10 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof; R” is selected from -NC-CH3, H2O, or -NC-C6-15 aryl; R3 and R4 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl 15 C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof; and refers to presence or absence of a bond.
15.
The device as claimed in claim 14, wherein the compound of Formula III is selected from 20 46
wherein M is selected from Ru, Os, Rh, Ir, Cr, Fe, Mn, Co, Ni, or Zn; Y is selected from -CH-, -C(C1-10 alkyl)-, or N; Xa, Xa’, Xb, Xb’, Xc, Xc’, Xd, Xd’, 5 Xe, Xe’, Xf, Xf’, Xg, and Xg’ are independently selected from Cl, Br, SCN, NCS, or I; and Ara, Ara’, Arb, Arb’, Arc, Arc’, Ard, Ard’, Are, Are’, Arf, Arf’, Arg, and Arg’, are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, 10 C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof. 47
16.
The device as claimed in claim 14, wherein the two conductive films are a top film and a bottom film.
17.
The device as claimed in claim 14, wherein the bottom film is in contact with the first surface of the active layer, and the top film is in contact with the opposing surface of the active layer. 5
18.
The device as claimed in claim 14, wherein the two conductive films are selected from a top film and a bottom film and the bottom film is in contact with the first surface of the active layer, and the top film is in contact with the opposing surface of the active layer.
19.
The device as claimed in claim 14, wherein the active layer is coated on the 10 bottom film.
20.
The device as claimed in claim 14, wherein the device further comprises a substrate selected from yttria stabilized zirconia (YSZ), hafnium oxide, silicon, silicon oxide, silicon nitride, or sapphire. In another embodiment of the present disclosure, the substrate is yttria stabilized zirconia (YSZ). 15
21.
The device as claimed in claim 14, wherein the device further comprises metal nanoparticles selected from gold, silver, platinum, tungsten, or chromium.
22.
The device as claimed in claim 14, wherein the active layer, the top film and the bottom film are arranged in series. 20
23.
The device as claimed in claim 14, wherein the two conductive films are independently selected from indium tin oxide (ITO), fluorine doped tin oxide (FTO), chromium, titanium, titanium nitride platinum, gold, tungsten, nickel, or graphite.
24.
The device as claimed in claim 14, wherein the active layer has a relative 25 permittivity in a range of 4 to 10 units depending on the applied voltage.
25.
The device as claimed in claim 14, wherein the active layer has a thickness in a range of 10 to 100nm; and the top film and the bottom film independently have a thickness in a range of 5 to 80 nm.
26.
The device as claimed in claim 14, wherein the active layer has a root mean 30 square roughness in a range of 0.1 to 4 nm. 48
27.
The device as claimed in claim 14, wherein the device exhibits a switching time in a range of 1 to 1 × 106 ns, in a voltage range of -5 to 5V.
28.
The device as claimed in claim 14, wherein the device is sensitive to an electrical voltage in a range of -5 to 5V; an electromagnetic radiation having a wavelength in a range of 200 to 1000 nm. 5
29.
The device as claimed in claim 14, wherein the active layer is configured to undergo capacitive switching, resistive switching, or a combination thereof, the switching being operable in digital mode with sharp capacitance or conductance transitions or in analog mode with gradual capacitance or conductance modulation depending on the applied stimulus. 10
30.
The device as claimed in claim 14, wherein the capacitive switching mode provides retention of distinct charge states for months without applied voltage, indicative of the stability of the underlying electronic states of the active material, that could also be used for resistive switching mode as well.
31.
The device as claimed in claim 14, wherein the device demonstrates 15 endurance sufficient to withstand at least 10? switching cycles without substantial degradation of performance, while maintaining stable capacitive and/or resistive switching characteristics.
32.
The device as claimed in claim 14, wherein the device exhibits long-term operational stability under ambient conditions, maintaining switching 20 performance over extended durations without significant loss of functionality.
33.
A process for preparation of the device claimed in any one of the claims 14-32, the process comprising: a) laminating an active layer on a bottom film with the opposing surface of the active layer in contact with the bottom 25 electrode; and b) depositing a top film on the first surface of the active layer to obtain the device.
34.
The process as claimed in claim 33, wherein the bottom film and top film are obtained by deposition methods independently selected from a vacuum vapor deposition method, cluster ion beam method, pulsed laser deposition 30 (PLD) method, chemical vapor deposition (CVD) method, plasma 49
polymerization method, molecular beam epitaxy (MBE) method, thermal/ electron beam evaporation or sputtering method. In another embodiment of the present disclosure, the the bottom film and top film are obtained by pulsed laser deposition (PLD) method, thermal/ electron beam evaporation or sputtering method. In another embodiment of the present disclosure, the 5 the bottom film and top film are obtained by pulsed laser deposition (PLD) method.
35.
The process as claimed in claim 33, wherein laminating the active layer is carried out by coating a solution comprising a solvent and at least one compound of Formula I, Formula II, Formula III or Formula Ia, upon the 10 bottom film.
36.
The process as claimed in claim 33, wherein the solvent is selected from acetonitrile (CH3CN), dimethyl formamide (DMF), dichloromethane (CH2Cl2), dichloroethane (ClCH2CH2Cl), chloroform (CH3Cl), methanol (CH3OH), ethanol (C2H5OH), or combinations thereof. 15
37.
The process as claimed in claim 33, wherein the coating is carried out by spin coating, jet printing, sol-gel coating, drying, or combinations thereof. In another embodiment of the present disclosure, the coating is carried out by spin coating and drying.
38.
The process as claimed in claim 33, wherein the coating is carried out by 20 spin coating at a speed in a range of 1000 to 12000 rpm, for a period in a range of 20 to 120 seconds.
39.
Use of the compound as claimed in any one of the claims 1-13, or the device. as claimed in any one of the claims 14-32.
40.
Use of the compound as claimed in any one of the claims 1-13, or the device 25 as claimed in any one of the claims 14-32, in electronic devices and electrical sensory and computing appliances. 50
ABSTRACT METALLIC COMPOUNDS AND MEMORY DEVICES COMPRISING THEREOF The present disclosure relates to metallic compounds and memory devices 5 comprising thereof. Disclosed are compounds of Formula I and II comprising transition metal centers (Cr, Mn, Fe, Co, Ni, Os, Pt, Pd, Ru, Rh, Ir) coordinated with halide ligands and optionally substituted aryl groups. Also disclosed are Formula III and Ia compounds with similar metal centers. These compounds exhibit multiple redox states and enhanced capacitive behavior. The present disclosure also provides 10 a device comprising two conductive films with an active layer containing the metallic compounds interposed therebetween. The device demonstrates switching times of 1 to 1×106 nanoseconds, multiple non-volatile capacitive states, and relative permittivity of 4-10 units. The capacitive switching mechanism enables energy-efficient operation suitable for neuromorphic computing and artificial 15 intelligence applications. 51 ,CLAIMS:I/We Claim:
1. A compound of Formula I
Formula I
wherein X1 and X1’ are independently selected from Cl, Br, I, NCS, SCN, 5 or N3; M1 is selected from Cr, Mn, Fe, Co, Ni, Os, Pt, Pd, Ru, Rh, or Ir; R’ is absent or is selected from -NC-C1-10 alkyl, or -NC-C6-15 aryl; R1 and R2 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof; and refers to presence or absence of a bond.
2.
A compound of Formula II
Formula II 15 43
wherein M2 is a transition group metal; and Ar1 and Ar2 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof. 5
3. The compound of Formula II as disclosed herein, wherein M2 is a transition group metal; and Ar1 and Ar2 are independently selected from C6-12 aryl, C1-12 heteroaryl, or C1-12 heterocyclyl, wherein the C6-12 aryl, C1-12 heteroaryl, or C1-12 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-5 alkyl, C1-5 alkoxy, C1-5 haloalkyl, cyano, or combinations thereof 10
4. The compound of Formula II as claimed in claim 2, wherein M2 is a transition group metal; and Ar1 and Ar2 are independently selected from C6-10 aryl, C6-10 heteroaryl, or C6-10 heterocyclyl, wherein the C6-10 aryl, C6-10 heteroaryl, or C6-10 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-3 alkyl, C1-3 alkoxy, C1-3 fluoroalkyl, C1-3 15 chloroalkyl, C1-3 bromoalkyl, C1-3 iodoalkyl, cyano, or combinations thereof.
5. The compound of Formula I as claimed in claim 1, wherein R’ is absent, when refers to presence of a single bond, M1 is selected from Cr, Mn, Fe, or Co, R1 and R2 are independently C6 aryl, and X1 and X1’ are 20 independently selected from Cl, Br, NCS, or SCN; and when refers to absence of a single bond, M1 is selected from Pt, or Pd; R1 and R2 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 25 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof.
6. The compound of Formula I as claimed in claim 1, wherein R’ is absent, refers to presence of a single bond, M1 is selected from Cr, Mn, Fe, or Co, R1 and R2 are C6 aryl, and X1 and X1’ are independently selected from Cl, Br, NCS, or SCN. 30 44
7. The compound of Formula I as claimed in claim 1, wherein R’ is absent, refers to absence of a single bond, M1 is selected from Pt, or Pd; R1 and R2 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 5 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof.
8. The compound of Formula I as claimed in claim 1, wherein R’ is -NC-C1-10 alkyl, refers to presence of a single bond; M1 is selected from Os, Ru, Rh, or Ir; R1 and R2 are C6 aryl; and X1 and X1’ are selected from Cl, or Br.
9. The compound of Formula II as claimed in claim 2, wherein M2 is selected 10 from Cr, Mn, Fe, Co, Ni, Zn, Ru, Rh, Os, or Ir; Ar1 and Ar2 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with one or more groups selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, or cyano. 15
10. The compound as claimed in any one of the claims 1-9, wherein the compound has at least two redox states.
11. The compound as claimed in any one of the claims 1-9, wherein the compound is sensitive to an electrical voltage in a range of -5 to 5V; an electromagnetic irradiation having a wavelength in a range of 200 to 1000 20 nm.
12. The compound as claimed in any one of the claims 1-9, wherein the compound exhibits one or more nonvolatile resistive, capacitive states, or combinations thereof.
13. The compound as claimed in any one of the claims 1-9, wherein the 25 compound exhibits one or more nonvolatile resistive or capacitive states which are stabilized by dipole interactions in the molecular structures of the compound.
14. A device comprising: a) two conductive films; and b) an active layer comprising a first surface and an opposing surface, interposed between the 30 two conductive films, wherein the active layer comprises at least one 45
compound selected from a group consisting of the compound of Formula I as claimed in claim 1, the compound of Formula II as claimed in claim 2, a compound of Formula III, and a compound of Formula Ia, its salts, stereoisomers, or solvates thereof,
5
Formula III Formula Ia
wherein M3 and M4 are independently selected from Ru, Os, Rh, Cr, Fe, Co, Mn, Ni, Ir, or Zn; Y and Y’ are independently selected from -CH-, -C(C1-10 alkyl)-, or N; X2, X2’, X3 and X3’ are independently selected from Cl, Br, I, SCN, or NCS; Ar is selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 10 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof; R” is selected from -NC-CH3, H2O, or -NC-C6-15 aryl; R3 and R4 are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl 15 C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof; and refers to presence or absence of a bond.
15.
The device as claimed in claim 14, wherein the compound of Formula III is selected from 20 46
wherein M is selected from Ru, Os, Rh, Ir, Cr, Fe, Mn, Co, Ni, or Zn; Y is selected from -CH-, -C(C1-10 alkyl)-, or N; Xa, Xa’, Xb, Xb’, Xc, Xc’, Xd, Xd’, 5 Xe, Xe’, Xf, Xf’, Xg, and Xg’ are independently selected from Cl, Br, SCN, NCS, or I; and Ara, Ara’, Arb, Arb’, Arc, Arc’, Ard, Ard’, Are, Are’, Arf, Arf’, Arg, and Arg’, are independently selected from C6-15 aryl, C1-15 heteroaryl, or C1-15 heterocyclyl, wherein the C6-15 aryl C1-15 heteroaryl, or C1-15 heterocyclyl is optionally substituted with a group selected from Cl, Br, I, 10 C1-10 alkyl, C1-10 alkoxy, C1-10 haloalkyl, cyano, or combinations thereof. 47
16.
The device as claimed in claim 14, wherein the two conductive films are a top film and a bottom film.
17.
The device as claimed in claim 14, wherein the bottom film is in contact with the first surface of the active layer, and the top film is in contact with the opposing surface of the active layer. 5
18.
The device as claimed in claim 14, wherein the two conductive films are selected from a top film and a bottom film and the bottom film is in contact with the first surface of the active layer, and the top film is in contact with the opposing surface of the active layer.
19.
The device as claimed in claim 14, wherein the active layer is coated on the 10 bottom film.
20.
The device as claimed in claim 14, wherein the device further comprises a substrate selected from yttria stabilized zirconia (YSZ), hafnium oxide, silicon, silicon oxide, silicon nitride, or sapphire. In another embodiment of the present disclosure, the substrate is yttria stabilized zirconia (YSZ). 15
21.
The device as claimed in claim 14, wherein the device further comprises metal nanoparticles selected from gold, silver, platinum, tungsten, or chromium.
22.
The device as claimed in claim 14, wherein the active layer, the top film and the bottom film are arranged in series. 20
23.
The device as claimed in claim 14, wherein the two conductive films are independently selected from indium tin oxide (ITO), fluorine doped tin oxide (FTO), chromium, titanium, titanium nitride platinum, gold, tungsten, nickel, or graphite.
24.
The device as claimed in claim 14, wherein the active layer has a relative 25 permittivity in a range of 4 to 10 units depending on the applied voltage.
25.
The device as claimed in claim 14, wherein the active layer has a thickness in a range of 10 to 100nm; and the top film and the bottom film independently have a thickness in a range of 5 to 80 nm.
26.
The device as claimed in claim 14, wherein the active layer has a root mean 30 square roughness in a range of 0.1 to 4 nm. 48
27.
The device as claimed in claim 14, wherein the device exhibits a switching time in a range of 1 to 1 × 106 ns, in a voltage range of -5 to 5V.
28.
The device as claimed in claim 14, wherein the device is sensitive to an electrical voltage in a range of -5 to 5V; an electromagnetic radiation having a wavelength in a range of 200 to 1000 nm. 5
29.
The device as claimed in claim 14, wherein the active layer is configured to undergo capacitive switching, resistive switching, or a combination thereof, the switching being operable in digital mode with sharp capacitance or conductance transitions or in analog mode with gradual capacitance or conductance modulation depending on the applied stimulus. 10
30.
The device as claimed in claim 14, wherein the capacitive switching mode provides retention of distinct charge states for months without applied voltage, indicative of the stability of the underlying electronic states of the active material, that could also be used for resistive switching mode as well.
31.
The device as claimed in claim 14, wherein the device demonstrates 15 endurance sufficient to withstand at least 10? switching cycles without substantial degradation of performance, while maintaining stable capacitive and/or resistive switching characteristics.
32.
The device as claimed in claim 14, wherein the device exhibits long-term operational stability under ambient conditions, maintaining switching 20 performance over extended durations without significant loss of functionality.
33.
A process for preparation of the device claimed in any one of the claims 14-32, the process comprising: a) laminating an active layer on a bottom film with the opposing surface of the active layer in contact with the bottom 25 electrode; and b) depositing a top film on the first surface of the active layer to obtain the device.
34.
The process as claimed in claim 33, wherein the bottom film and top film are obtained by deposition methods independently selected from a vacuum vapor deposition method, cluster ion beam method, pulsed laser deposition 30 (PLD) method, chemical vapor deposition (CVD) method, plasma 49
polymerization method, molecular beam epitaxy (MBE) method, thermal/ electron beam evaporation or sputtering method. In another embodiment of the present disclosure, the the bottom film and top film are obtained by pulsed laser deposition (PLD) method, thermal/ electron beam evaporation or sputtering method. In another embodiment of the present disclosure, the 5 the bottom film and top film are obtained by pulsed laser deposition (PLD) method.
35.
The process as claimed in claim 33, wherein laminating the active layer is carried out by coating a solution comprising a solvent and at least one compound of Formula I, Formula II, Formula III or Formula Ia, upon the 10 bottom film.
36.
The process as claimed in claim 33, wherein the solvent is selected from acetonitrile (CH3CN), dimethyl formamide (DMF), dichloromethane (CH2Cl2), dichloroethane (ClCH2CH2Cl), chloroform (CH3Cl), methanol (CH3OH), ethanol (C2H5OH), or combinations thereof. 15
37.
The process as claimed in claim 33, wherein the coating is carried out by spin coating, jet printing, sol-gel coating, drying, or combinations thereof. In another embodiment of the present disclosure, the coating is carried out by spin coating and drying.
38.
The process as claimed in claim 33, wherein the coating is carried out by 20 spin coating at a speed in a range of 1000 to 12000 rpm, for a period in a range of 20 to 120 seconds.
39.
Use of the compound as claimed in any one of the claims 1-13, or the device. as claimed in any one of the claims 14-32.
40.
Use of the compound as claimed in any one of the claims 1-13, or the device 25 as claimed in any one of the claims 14-32, in electronic devices and electrical sensory and computing appliances.