FORM 2
THE PATENTS ACT, 1970
(Act 39 of 1970)
COMPLETE SPECIFICATION
(See Section 10)
Title: "WATER DISPERSIBLE METAL NANOPARTICLES OBTAINED
FROM NOVEL CALIX[4]RESOCINARENE HYDRAZIDES AND APPLICATIONS THEREOF".
Applicants: 1. Jain Vinod kumar
2. Makwana Bharat Ambalal
3. Vyas Disha Jayantkumar
4. Bhatt Keyur Dineshchandra
5. Darji Savan Maheshbhai
6. Mishra Divya Ram
7. Agrawal Yadvendra Kumar**
Address: Department of Chemistry, School of Sciences, Gujarat
University, Ahmedabad-380009, Gujarat, India.
** Institute of Research and Development, Gujarat Forensic Sciences University, DFS Head Quarters, Sector 18-A, Near Police Bhavan, Gandhinagar-382007,Gujarat -India,
Nationality: Indian
The following specification describes the nature of the invention:

FIELD OF THE PRESENT INVENTION
The present invention relates to novel Calix[4]resorcinarene hydrazides of formula (X).

Particularly, the present invention relates to novel
Calix[4]resorcinarene polyhydrazide of formula (A),
Calix[4]resorcinarene tetrahydrazide formula (B) and formula (C).



The present invention also relates to the process for the preparation of
calix[4]resorcinarene polyhydrazide of formula (A),
calix[4]resorcinarene tetrahydrazide formula (B) and formula (C) and also for the preparation of water dispersible stable metal nano particles obtained from the calix[4]resorcinarene hydrazides of formula (A), formula (B) & formula (C).
BACKGROUND OF THE PRESENT INVENTION
There has been lot of research going on to prepare water dispersible and stable metal nanoparticles. Among these Au an Ag nanoparticles top the list.
In one of the references, i.e. "Journal of Nanoparticle Research, 13 (2011) 4997-5007", Hydrazine hydrate has been used to reduce the metal ions to form nanoparticles but the nanoparticles formed by this method lacks stability. To make them stable we have to use some capping agent or stabilizing agent which can increase the stability of nanoparticles by preventing them to agglomerate which is disclosed in the reference "Journal of Physics and Chemistry of Solids, 68 (2007) 2252-2261".
Previously, Resorcinarene and other calixarene derivatives have been used to enhance the dispersion of colloidal metal particles in various organic solvents, as well as their self-assembly into well defined nanostructures with novel collegative properties.

A large number of methods have been developed for the synthesis of meta] nanoparticles in last two decades, involving the use of different protecting reagents, such as alkylthiols, alkylamines, polymers and other ligands.
Recently, as per the disclosure of (i) "Langmuir 18 (2002) 3676" & (ii) "Supramol. Chem. 17 (2005) 173", Balasubramanian and co-workers made a study of the dispersion and stability of resorcinarene-encapsulated gold nanoparticles through extracting gold particles from gold hydrosol into toluene or chloroform using resorcinarene surfactant as an extractant, and they revealed that the resorcinarene surfactants with sulphur functionalized head groups could make the mid nanometer sized gold particles stably dispersed in organic solvents.
In the reference "Angew. Chem. 117 (2005) 2973", Tshikhudo et al. has reported the preparation and chemical properties of water-soluble gold nanoparticles protected by sulfanylalkyl oligo (ethylene glycol) and sulfur-containing calix[4]arene ligands.
In another reference "Colloids Surf. A 181 (2001) 255", Sastry and coworkers prepared the hydrophobic gold nanoparticles capped by fatty amine with the simplified Brust "twophase" method and made a research into the interaction between the surface-bound alkylamines and gold nanoparticles.
There are several other methods available to reduce the metal ions to form nanoparticles.
One of the reference "J Nanopart Res (2011) 13:4997-5007" has disclosed a method wherein hydrazine hydrate is used as a reducing agent but the nanoparticles formed by this method lack stability.
The other reference "Journal of Physics and Chemistry of Solids 68 (2007) 2252-2261" has disclosed a process of preparing stable gold

nanoparticles using aminoresoncinarene (TOMR) thus TOMR is used as capping/stabilizing agent which can increase the stability of nanoparticles by preventing them to agglomerate.
The inventors have thought of designing few molecules which have properties of hydrazine hydrate to act as reducing agent and must have web type of structure with inherent hollow cavity to encapsulate/cap/engulf/stabilize the reduced nanoparticles.
For this purpose, calix[4]resorcinarenes have been selected which can be easily obtained by acid catalysed condensation of resorcinol or 2-substituted resorcinol with various aromatic aldehyde, by heating the constituents to reflux in a mixture of ethanol and concentrated HC1 for several hours. Usually cyclo tetramer crystallizes out from reaction mixture, in a reasonable to high yields via simple one step reaction, without using template, although for different aldehyde, different optimal reaction conditions exist.
The compound of formula (1) has 12 hydroxy groups, Compounds of formula (2) and (3) have 4,8 hydroxy groups, respectively, on the periphery of basic calix platform. Compound (1) and compound (2) were further functionalized to give compound of formula (4) and (5). Compound (3), (4) and compound (5) were then treated with hydrazine hydrate to yield tetrahydrazide derivative (C) and (B) and polyhydrazide of formula (A).
Now, with this present invention, inventors have efficiently used
calix[4]resorcinarene polyhydrazide of formula (A),
calix[4]resorcinarene tetrahydrazide (B) and formula (C) for the preparation of water dispersible stable metal nano particles.
OBJECTS OF THE PRESENT INVENTION
It is an object of the present invention to provide novel calix[4]resorcinarene polyhydrazide of formula (A).

It is also an object of the present invention to provide novel calix[4]resorcinarene tetrahydrazide of formula (B) and formula (C).
It is further an object of the present invention to provide safe, industry viable process for the preparation of calix[4Jresorcinarene polyhydrazide of formula (A).
It is further an object of the present invention to provide safe, industry viable process for the preparation of calix[4]resorcinarene tetrahydrazide formula (B) and formula (C).
It is yet another object of the present invention to provide stable water dispersible metal nano particles derived from calix[4]resorcinarene polyhydrazide of formula (A).
It is yet another object of the present invention to provide stable water dispersible metal nano particles derived from calix[4]resorcinarene tetrahydrazide formula (B) and formula (C).
It is an object of the present invention to provide the usage of nanoparticles as selective chemo sensors and bio sensor also.
It is an object of the present invention to provide the usage of nanoparticles as antibacterial and antifungal agents in various pharmaceutical preparations.
Yet another object of the present invention to include use of nanoparticles in nonvolatile random access memory device or resistive random-access memory device (RRAM).
BRIEF DESCRIPTION OF DRAWINGS
FIG.l shows FT-IR of calix[4]resorcinarene hydrazide of formula (A) FIG.2 shows lH NMR of calix[4jresorcinarene hydrazide of formula (A) FIG.3 shows MASS Spectra of calix[4]resorcinarene hydrazide of formula (A)

FIG.4 shows FT-IR of calix[4]resorcinarene hydrazide of formula (B)
FIG.5 shows 1H NMR of calix[4]resorcinarene hydrazide of formula (B)
FIG.6 shows MASS Spectra of calix[4]resorcinarene hydrazide of
formula (B)
FIG.7 shows FT-IR of calix[4]resorcinarene hydrazide of formula (C)
FIG.8 shows !H NMR of calix[4]resorcinarene hydrazide of formula (C)
FIG.9 shows MASS Spectra of calix[4)resorcinarene hydrazide of
formula (C)
FIG. 10 shows a transmission electron micrograph (TEM) of the gold
nanoparticles produced in accordance with Example- Al.
FIG. 11 shows a transmission electron micrograph (TEM) of the gold
nanoparticles produced in accordance with Example- A2.
FIG. 12 shows a transmission electron micrograph (TEM) of the gold
nanoparticles produced in accordance with Example- A3.
FIG. 13 shows an energy dispersive graph (EDX) of the gold
nanoparticles produced in accordance with Example-Al.
FIG. 14 shows an energy dispersive graph (EDX) of the gold
nanoparticles produced in accordance with Example-A2.
FIG. 15 shows an energy dispersive graph (EDX) of the gold
nanoparticles produced in accordance with Example-A3.
FIG. 16 shows stability of the gold nanoparticles produced in
accordance with Example-Al at pH between 4 to 10.
FIG. 17 shows stability of the gold nanoparticles produced in
accordance with Example-A2 at pH between 4 to 10.
FIG. 18 shows stability of the gold nanoparticles produced in
accordance with Example-A3 at pH between 4 to 10.
FIG. 19 shows stability for 60 days, analyzed through Surface Plasmon
Resonance (SPR) of the gold nanoparticles produced in accordance
with Example-Al.
FIG.20 shows stability for 120 days, analyzed through Surface
Plasmon Resonance (SPR) of the gold nanoparticles produced in
accordance with Example-A2.

FIG.21 shows stability for 120 days, analyzed through Surface
Plasmon Resonance (SPR) of the gold nanoparticles produced in
accordance with Example-A3.
FIG.22 shows Surface Plasmon Resonance (SPR) of the gold
nanoparticles produced in accordance with Example-Al.
FIG.23 shows Surface Plasmon Resonance (SPR) of the gold
nanoparticles produced in accordance with Example-A2.
FIG.24 shows Surface Plasmon Resonance (SPR) of the gold
nanoparticles produced in accordance with Example-A3.
FIG.25 shows a transmission electron micrograph (TEM) of the silver
nanoparticles produced in accordance with Example- Bl.
FIG.26 shows a transmission electron micrograph (TEM) of the silver
nanoparticles produced in accordance with Example- B2.
FIG.27 shows a transmission electron micrograph (TEM) of the silver
nanoparticles produced in accordance with Example- B3.
FIG.28 shows an energy dispersive graph (EDX) of the silver
nanoparticles produced in accordance with Example-B 1.
FIG.29 shows an energy dispersive graph (EDX) of the silver
nanoparticles produced in accordance with Example-B2.
FIG.30 shows stability of the silver nanoparticles produced in
accordance with Example-B 1 at pH between 4 to 10.
FIG.31 shows stability of the silver nanoparticles produced in
accordance with Example-B2 at pH between 4 to 7.
FIG.32 shows stability of the silver nanoparticles produced in
accordance with Example-B3 at pH between 4 to 10.
FIG.33 shows Surface Plasmon Resonance (SPR) of the silver
nanoparticles produced in accordance with Example-B 1.
FIG.34 shows Surface Plasmon Resonance (SPR) of the silver
nanoparticles produced in accordance with Example-B2.
FIG.35 shows Surface Plasmon Resonance (SPR) of the silver
nanoparticles produced in accordance with Example-B3.

FIG.36 shows stability for 120 days, analyzed through Surface
Plasmon Resonance (SPR) of the silver nanoparticles produced in
accordance with Example-Bl.
FIG.37 shows stability for 160 days, analyzed through Surface
Plasmon Resonance (SPR) of the silver nanoparticles produced in
accordance with Example-B2.
FIG.38 shows stability for 120 days, analyzed through Surface
Plasmon Resonance (SPR) of the silver nanoparticles produced in
accordance with Example-B3.
FIG.39 shows fluorescence spectra of CPH-AuNps (Exp Al) on addition
of Cu(II) , Zn(II) , Cd(II), Mn(II), Pb(II), Ni(II) and Hg(II) ions (10 |iM).
FIG.40 shows fluorescence response of CPH-AuNps (Exp Al) on
addition of Hg(II) solution) 10 nM to 10 μM and the inset shows a Stern-
Volmer plot of intensity versus concentration of Hg(II) ions.
FIG.41 shows Fluorescence spectra of AuNps (Exp A2) in presence of
Zn(II), Ag(I), Hg(II), Cd(II), Co(II), Ni(II), Fe(II) and Cu(II) ions.
FIG.42 shows Fluorescence spectra of AuNps(Exp A2) Cu(II) ions on
addition of leucine (InM to 10μM).
FIG.43 shows Fluorescence spectra of AuNps (Exp A3) on addition
various amino acids (1 μM) at pH 7.0.
FIG.44 shows fluorescence response of CPH-AgNps (Exp Bl) on
addition of Fe(III) ions (0.1 nM to 10 nM) and the inset shows a Stern-
Volmer plot of intensity versus concentration of Fe(III) ions.
FIG.45 shows fluorescence response of OMRTH-AgNps (Exp B2) on
addition of Cd(II)(10 nM to 1 μM) and the Inset shows a stern-volmer
plot of intensity versus concentration of Cd(II).
FIG.46 shows Fluorescence response of CRTH-AgNps (Exp B3) on
addition of Pb(II)(l nM to 0.9μM) the Inset shows a stern-volmer plot
of intensity versus concentration of Pb(II).
FIG.47 shows Fluorescence response of CPH-AuNps(Exp Al) in
presence of L-Dopa (10 nM to 10 μM).

FIG.48 shows Fluorescence response of CPH-AgNps(Exp Bl) on
addition of histidine (10 nM to 10 μM) and the inset shows a Stern-
Volmer plot of intensity versus concentration of histidine.
FIG.49 shows absorption spectra of CT-DNA and S-DNA.
FIG. 50a & 50b show Absorption spectra of a) CPH-AuNps(Exp Al) and
b) CPH-AgNps(Exp Bl) with CT-DNA and S-DNA.
FIG. 51 shows DPPH antioxidant assay at (λmax 517) of CPH-
AuNps(Exp Al) and b) CPH-AgNps(Exp Bl) with compared to
standards.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
Inventors have thought of designing novel compounds which have all the chemical and physical properties of hydrazine hydrate to act as reducing agent and must have web type of structure with inherent hollow cavity to encapsulate/cap/engulf / stabilize the reduced nanoparticles.
Thus, the present invention is directed to calix[4]resorcinarene hydrazides of formula (X).


More particularly, the present invention is directed to
calix[4]resorcinarene polyhydrazide of formula (A),
calix[4]resorcinarene tetrahydrazide formula (B) and formula (C).


Further, the present invention is also directed to a process for the preparation of novel calix[4]resorcinarene polyhydrazide of formula (A), calix[4]resorcinarene tetrahydrazide formula (B) and formula (C).
A general process for the preparation of calix[4]resorcinarene
hydrazides of formula (X) may be provided as follows:
Suspending the desired compound selected from formula (4), formula
(3) or formula (5) with hydrazine hydrate in a mixture of
ethanol:toluene;
Refluxing the mixture under stirring to give corresponding
calix[4]resorcinarene hydrazide of formula (X);
Optionally purifying the calix[4]resorcinarene hydrazide of formula (X)
to obtain pure calix[4]resorcinarene hydrazide of formula (X).



Scheme-1, Scheme-2 and Scheme-3 have provided a schematic diagram for the preparation of novel calix[4]resorcinarene polyhydrazide of formula (A), calix[4Jresorcinarene tetrahydrazide formula (B) and formula (C) respectively.
Related closest reference for the preparation of calix[4]resorcinarene polyhydrazide of formula (A) is referenced in "D.J. Vyas, B.A. Makwana, H.S. Gupte, K.D. Bhatt, V.K. Jain, An Efficient One Pot Synthesis of Water-Dispersible Calix [4] arene Polyhydrazide Protected

Gold Nanoparticles-A Turn Off Fluorescent Sensor for Hg [II] Ions, Journal of nanoscience and nanotechnology, 12 (2012) 3781-3787",

Compounds of formula (1), (2) and (3) as disclosed in scheme-1, scheme-2 & scheme-3 have been reported in prior art references and the same have been prepared with the help of the following references: (i) M. Shen, W.-f. Chen, Y. Sun, C.-g. Yan, Synthesis and characterization of water-soluble gold colloids stabilized with aminoresorcinarene, Journal of Physics and Chemistry of Solids, 68 (2007) 2252-2261. (ii) S. Miao, R.D. Adams, D.-S. Guo, Q.-F. Zhang, Structural conformers of symmetry substituted resorcin[4Jarenes, Journal of Molecular Structure, 659 (2003) 119-128. (iii) Y.K. Agrawal, R.N. Patadia, Microwave-Assisted Synthesis of Calix[4]resorcinarene Hydroxamic Acids, Synthetic Communications, 36 (2006) 1083-1092.

Further, below references have been referred in the process for the preparation of compounds of formula (4), (5):
(a) S. Miao, R.D. Adams, D.-S. Guo, Q.-F. Zhang, Structural conformers of symmetry substituted resorcin[4]arenes, Journal of Molecular Structure, 659 (2003) 119-128.
(b) J. Han, Y.H. Cai, L. Liu, C,G. Yan, Q. Li, Syntheses, crystal structures, and electrochemical properties of multi-ferrocenyl resorcinarenes, Tetrahedron, 63 (2007) 2275-2282.
(c) J. Han, C.-G. Yan, Synthesis, crystal structure and configuration of resorcinarene amides, Journal of Inclusion Phenomena and Macrocyclic Chemistry, 61 (2008) 119-126.
In a first aspect, there is provided a novel calix[4]resorcinarene polyhydrazide of formula (A) and process for the preparation thereof.

Accordingly, a process for the preparation of calix[4]resorcinarene polyhydrazide of formula (A) comprises:
Suspending the compound of formula (4) with hydrazine hydrate in
a mixture of ethanol:toluene;
refluxing the mixture under stirring to give calix[4]resorcinarene
polyhydrazide of formula (A);
optionally purifying the calix[4]resorcinarene polyhydrazide of
formula (A) to obtain pure calix[4]resorcinarene polyhydrazide of
formula (A).

Reaction is carried out at a reflux temperature of a solvent used in the reaction. The preferred reaction temperature is comprised between 70°C and 100° C, more preferably between 70°C and 90° C.
Solvent used in the reaction is selected from the solvents like ethanol, toluene or mixtures thereof. Quantity of the solvent used in the reaction is as per the reaction requirement which may vary between 10 to 120 times volume that depend on the starting materials used in the reaction, preferably reaction proceeds faster if 40 to 120 times volume of solvent is used in the reaction. Further, in case if mixture of toluene:ethoanol is used in the reaction, the ratio of mixture may vary between 20:80v/v to 80:20v/v of toluenerethanol.
Hydrazine hydrate used in the reaction is added in a molar ratio selected from 5 to 20 compared to the molar ratio of the compound of formula (4). Preferably hydrazine hydrate is added in a molar ratio selected from 10 to 15 compared to the molar ratio of the compound of formula (4).
The process is typically carried out at atmospheric pressure. Of course, pressures below or above atmospheric pressure are not excluded by the present invention.
Reaction mixture is stirred for a period of 50-80 hrs and once the reaction is completed, the reaction mass is taken for solvent removal using distillation method, under vacuum. Solid product is obtained which is further suspended in dichloromethane, stirred for 15 minutes and filtered it to give calix[4jresorcinarene polyhydrazide of formula (A).
If desired, calix[4]resorcinarene polyhydrazide of formula (A) may be taken for purification. Purification stage is performed by recrystallization in water. Calix[4]pyrrole octahydrazide of formula (A) is dissolved in hot water, stirred it for 15-30 minutes, cooled to room temperature and then to 0-5°C. Reaction mass is then stirred to 0-5°C for 30 minutes, filtered to give pure calix[4]pyrrole octahydrazide of

formula (A). It is also possible to use other solvent for the purification purpose, the only condition to carry out purification stage is that the calix[4]pyrrole ocatahydrazide of formula (A) must be soluble and it gets reprecipitated once appropriate conditions applied.
In the second aspect, there is provided a novel calix[4]resorcinarene tetrahydrazide of formula (B) and process for the preparation thereof.

Scheme-2 has provided a schematic diagram of compound of formula (B).
Accordingly, a process for the preparation of calix[4]resorcinarene tetrahydrazide of formula (B) comprises:
Suspending the compound of formula (5) with hydrazine hydrate in
a mixture of ethanol:toluene;
refluxing the mixture under stirring to give calix[4]resorcinarene
tetrahydrazide of formula (B);
optionally purifying the caIix[4]resorcinarene tetrahydrazide of
formula (B) to obtain pure calix[4]resorcinarene tetrahydrazide of
formula (B).
Reaction is carried out at a reflux temperature of a solvent used in the reaction. The preferred reaction temperature is comprised between 70°C and 100° C, more preferably between 70°C and 90° C.

Solvent used in the reaction is selected from the solvents like ethanol, toluene or mixtures thereof. Quantity of the solvent used in the reaction is as per the reaction requirement which may vary between 10 to 120 times volume that depend on the starting materials used in the reaction, preferably reaction proceeds faster if 40 to 120 times volume of solvent is used in the reaction. Further, in case if mixture of toIuene:ethoanol is used in the reaction, the ratio of mixture may vary between 20:80v/v to 80:20v/v of toluene:ethanol.
Hydrazine hydrate used in the reaction is added in a molar ratio selected from 5 to 20 compared to the molar ratio of the compound of formula (5). Preferably hydrazine hydrate is added in a molar ratio selected from 10 to 15 compared to the molar ratio of the compound of formula (5).
The process is typically carried out at atmospheric pressure. Of course, pressures below or above atmospheric pressure are not excluded by the present invention.
Reaction mixture is stirred for a period of 50-80 hrs and once the reaction is completed, the reaction mass is taken for solvent removal using distillation method under vacuum. Solid product is obtained which is further suspended in dichloromethane, stirred for 15 minutes and filtered it to give calix[4]resorcinarene tetrahydrazide of formula (B).
In the third aspect, there is provided a novel calix[4Jresorcinarene tetrahydrazide of formula (C) and process for the preparation thereof. Scheme-3 has provided a schematic diagram of compound of formula (C).


Accordingly, a process for the preparation of calix[4]resorcinarene tetrahydrazide of formula (C) comprises:
Suspending the compound of formula (3) with hydrazine hydrate in
a mixture of ethanol:toluene;
refluxing the mixture under stirring to give calix[4]resorcinarene
tetrahydrazide of formula (C);
optionally purifying the calix[4]resorcinarene tetrahydrazide of
formula (C) to obtain pure calix[4]resorcinarene tetrahydrazide of
formula (C).
Reaction is carried out at a reflux temperature of a solvent used in the reaction. The preferred reaction temperature is comprised between 70°C and 100° C, more preferably between 70°C and 90° C.
Solvent used in the reaction is selected from the solvents like ethanol, toluene or mixtures thereof. Quantity of the solvent used in the reaction is as per the reaction requirement which may vary between 10 to 120 times volume that depend on the starting materials used in the reaction, preferably reaction proceeds faster if 40 to 120 times volume of solvent is used in the reaction. Further, in case if mixture of toluene:ethoanol is used in the reaction, the ratio of mixture may vary between 20:80v/v to 80:20v/v of toluene:ethanol.
Hydrazine hydrate used in the reaction is added in a molar ratio selected from 5 to 20 compared to the molar ratio of the compound of formula (3). Preferably hydrazine hydrate is added in a molar ratio

selected from 10 to 15 compared to the molar ratio of the compound of formula (3).
The process is typically carried out at atmospheric pressure. Of course, pressures below or above atmospheric pressure are not excluded by the present invention.
Reaction mixture is stirred for a period of 50-80 hrs and once the reaction is completed, the reaction mass is taken for solvent removal using distillation method under vacuum. Solid product is obtained which is further suspended in dichloromethane, stirred for 15 minutes and filtered it to give calix[4]resorcinarene tetrahydrazide of formula (C).
Most related closest references for the preparation of compounds of formula (A), (B) and (C) are as follows:
(i) Tetrahedron, 63 (2007) 2275-2282.
(ii) Journal of Inclusion Phenomena and Macrocyclic Chemistry, 61 (2008) 119-126.
(iii) Journal of nanoscience and nanotechnology, 12 (2012) 3781-3787.
In the fourth aspect, the present invention has disclosed water dispersible stable metal nanoparticles and process for the preparation thereof.
Most of the methods using calix[4]resorcinarene for the formation of metal nanoparticles limit their potential application because they are prepared in organic solvents. This is due to poor solubility of calix[4]resorcinarene in aqueous media which results in nanoparticles with a poor shelf life. Compared with nanoparticles dispersed in organic phases, the resorcinarene-functionalized metal nanoparticles dispersed in water are expected to have better biocompatibility and more promising applications. Synthesised calix[4]resorcinarene

polyhydrazide of formula (A), calix[4]resorcinarene tetrahydrazide of formula (B) and formula (C) are water soluble and used the same for the preparation of water dispersible nanoparticles.
Further, Inventors have found that most of the earlier reported methods have used reducing agent and capping agent separately to prepare reasonably stable metal nanoparticles. Few reports are also available where only one compound has acted as reducing as well as stabilizing agent but the nanoparticles obtained by such agents lack stability. Table-1 shows these references wherein the comparison of stability of the formed metal nano particles is provided. Table-1: Comparison of stability of the formed metal nanoparticles:

Reference Compound Reducing Synthesized Stability
name agent Nanoparticles
Journal of Inclusion Tetrathiol Sodium AuNPs 8 days
Phenomena and Resorcinarenes borohydride
Macrocyclic Chemistry 41:
83-86,(2001)
Journal of Colloid and C- Trisodium AuNPs Good
Interface Science:297, 584- undecylcalix[4]- citrate
588 (2006) resorcinarene
J. Dispersion Science and Tetrabenzylthiol Trisodium AuNPs 8 days
Tech.: 22(5), 485-489 Resorcinarenes citrate
(2001)
ACS Nano. Vol: 4(4), 2129- Polyamine Sodium AuNPs, AgNPs, 1 month
2141 (2010) Resorcinarenes borohydride PtNPs, PdNPs
Whereas inventors in the present invention, have developed an efficient, eco-friendly and simple method for the preparation of metal nano particles (Metal Nps) in which compounds of the formula (A), formula (B) & formula (C) of the present invention acted as both reducing as well as stabilizing agent and no need to use reducing agent or stabilizing agent separately.

Now, a general process for the preparation of calix[4]resorcinarene hydrazide metal nanoparticles comprises the steps of:
(a) mixing aqueous solution of calix[4]resorcinarene hydrazide of formula (X) with aqueous solution of metal salt to get the reaction mass;
(b) stirring it to obtain metal colloids in the reaction mass;
(c) carrying out centrifugation of the colloidal reaction mass to get metal nano particles derived from calix[4]resorcinarene hydrazide of formula (X).
Accordingly, in step (a), mixing is done at a temperature between 20°C to 35°C. At the time of mixing the solutions, vigorous stirring is required. In case, if vigorous stirring is not applied then the metal nano particles with the desired particle size will not be obtained.
Calix[4]resorcinarene hydrazide of formula (X) is selected from compounds of formula (A), formula (B) or formula (C).
The aqueous solution of calix[4]resorcinarene hydrazide of formula (X) and aqueous solution of metal salt is mixed in a ratio of 1:1 for ex: Under vigorous stirring, ImMol aqueous solution of calix[4]resorcinarene hydrazide of formula (X) is mixed with ImMol solution of metal salt at a boiling temperature and stirred for half an hour to give metal colloids which is further taken for centrifugation atleast for three times to give desired metal nano particles.
With the help of the above said method, Silver (Ag) and Gold (Au) nano particles of caIix[4Jresorcinarene hydrazide of formula (X) may be obtained. To get the silver nanoparticles, silver nitrate (AgNO3) is used as the metal salt while to get the gold nanoparticles, HAuCU is used as the metal salt.
Silver and Gold Nanoparticles of calix[4]resorcinarene hydrazide of formula (X) were found to be stable at room temperature, at different pH and also over a long period of time. It was also found that silver

and gold nanoparticles of formula (A), formula (B) and formula (C) are selective and sensitive fluorescent chemo sensors.
The very high stability of silver nanoparticles is due to the web type architecture of all the compounds selected from formula (A), formula (B) and formula (C), which has eight hydrazide groups on its periphery and the inherent hollow cavity. Hydrazide group on periphery reduces the metal ions to metallic silver which further nucleates to form the nanoparticles which are engulfed in the inherent hollow cavity of compounds of formula (A), formula (B) and formula (C) to give more or less uniform spherical size. The web type structure of the compounds shields the nanoparticles so effectively that they do not aggregate and retain their size for months together.
The nanoparticles have shown good antimicrobial activity as well as interaction with DNA. Nanoparticles being stable in the aqueous system provides ample opportunity of their application in various biological systems.
EXAMPLES
Materials and methods:
All reagents were of analytical reagent grade and were used without further purification. Solvents employed were purified by standard procedure before use.
For the purpose of preparation of the compounds of formula (A), formula (B) and formula (C), the starting materials, reactants and solvents are commercially available in the market. Starting materials i.e. compounds of formula (3), formula (4) & formula (5) may also be prepared using any process which is reported in the prior art.
Melting points were determined in open capillary on Veego (Model: VMP-D) electronic apparatus and are uncorrected.

FTIR spectra (4000-400cm-1) recorded on Simadzu 8400-S spectrophotometer using KBr disk.
Nuclear magnetic resonance (1H NMR) spectra were recorded on Bruker 500 MHz model spectrometer using CDCl3 as a solvent and TMS as internal reference (Chemical shifts in 5 ppm).
Ex-1: Preparation of calix[4]resorcinarene polyhydrazide of formula (A):
A mixture of compound (3) (4.0 g, 2 mmol) and hydrazine hydrate (15
ml, 80%) in 20 ml of ethanol was refluxed for 24 hours, allowed to cool
at room temperature. Pink coloured solid precipitated out which was
washed with ethanol(lOml) to get pure compound of formula (A).
Melting point: >250°C.
IR as per Fig. 2.
(Fig. 3): MASS: (M+) 1776.6
Ex-2: Preparation of calix[4]resorcinarene tetrahydrazide of formula (B):
A mixture of compound (5) (5.0 g, 3.9 mmol) and hydrazine hydrate (20
ml, 80%) in 25 ml of ethanol was refluxed for 24 hours, allowed to cool
at room temperature. Ethanol and excess hydrazine hydrate is then
removed under vacuum to get the compound of formula (B). The
product was then recrystallized in ethanol (5ml) to give white solid
product of compound of formula (B).
Melting point: >300°C.
IR as per Fig. 4
(Fig. 5): 1HNMR
(Fig. 6): MASS: (M+) 1257.4

Ex-3: Preparation of calix[4]resorcinarene tetrahydrazide of formula (C):
A mixture of compound (4) (4.0 g, 3.9 mmol) and hydrazine hydrate (20 ml, 80%) in 15 ml of ethanol was refluxed for 24 hours, allowed to cool at room temperature. Pink coloured solid precipitated out which was washed with ethanol(8ml) to get pure compound of formula (C). Melting point: >245°C. IR as per Fig. 7 (Fig. 8): lH NMR (Fig. 9): MASS: (M+) 1023.5
Preparation of metal nanoparticles:
Ex-Al: Synthesis of gold nanoparticles of formula (A) (CPH-AUNps):
25 mL (ImM) solution of HAuCl4 was added to a 30 mL of conical flask and then 25 mL (1 mM) aqueous solution of calix[4]resorcinarene hydrazide of formula (A) was added rapidly under vigorous stirring. Calix[4]pyrrole octahydrazide stabilized gold colloids (AuNps) were obtained immediately but vigorous stirring was continued for 15 minutes to ensure complete homogenization. The transparent colourless solution was converted to the characteristic ruby red colour, indicating the formation of Gold nanoparticles of formula (A). The said solution was then subjected to repeated centrifugation (3 times) at 5000 RPM, washed with a copious amount of deionized water to remove uncoordinated molecules and again redispersed in deionized water for further studies. The stability of the colloidal solution at room temperature was observed to be more than four months.
Ex-A2 (OMTRH-AuNps): In a similar manner, gold nanoparticles of calix[4]resorcinarene hydrazide of formula (B) may also be obtained.
Ex-A3 (CRTH-AuNps): In a similar manner, gold nanoparticles of calix[4]resorcinarene hydrazide of formula (C) may also be obtained.

Ex-Bl: Synthesis of silver nanoparticles of formula (A) (CPH-AgNps):
25 mL (1 mM) aqueous solution of calix[4]resorcinarene hydrazide of formula (A) was added rapidly into 25 mL (ImM) boiling solution of AgN03 in a 30 mL of conical flask under vigorous stirring. Calix[4]resorcinarene hydrazide of formula (A) stabilized silver colloids (AgNps) were obtained immediately but vigorous stirring was continued for 30 minutes to ensure complete homogenization. The transparent colourless solution was converted to the characteristic pale yellow colour, indicating the formation of silver nanoparticles of calix[4]resorcinarene hydrazide of formula (A). The said solution was then subjected to repeated centrifugation (3 times) at 5000 RPM, washed with a copious amount of deionized water to remove uncoordinated molecules and again redispersed in deionized water for further studies. The stability of the solution at room temperature was observed to be more than four month.
Ex-B2 (OMTRH-AgNps): In a similar manner, silver nanoparticles of calix[4]resorcinarene hydrazide of formula (B) may also be obtained.
Ex-B3 (CRTH-AgNps): In a similar manner, silver nanoparticles of calix[4]resorcinarene hydrazide of formula (C) may also be obtained.
While the invention has been described and exemplified in sufficient detail for those skilled in this art to make and use it, various alternatives, modifications, and improvements should be apparent without departing from the spirit and scope of the invention.
CHARACTERIZATION OF NANOPARTICLES
(A) Gold nanoparticles as per examples (Al), (A2) & (A3):
The synthesized gold nanoparticles as per examples (Al), (A2) & (A3) were characterized by UV-Visible spectroscopy, transmission electron microscopy (TEM) and particle size analyzer (PSA). The

observations confirmed the high stability of gold Nanoparticle in aqueous solution over a long period of time and even at varied pH.
Characterization of Gold nanoparticles by particle size analyzer, Transmission Electron Microscope (TEM) and Energy Dispersive X-Ray (EDX):
A drop of dilute solution of aqueous nanoparticles was placed on carbon coated copper grids and was dried in vacuum and directly observed in the TEM. The morphology and particles size of gold nanoparticles of formula (A), formula (B) and formula (C) as shown in figure 10, figure 11 and figure 12 respectively revealed that the particles are roughly spherical in shape and uniform in size, as well as, well dispersed with a narrow size distribution with an average particles size of 8+2 nm which is less than 50nm.
The size distribution of the gold nanoparticles of formula (A), formula (B) and formula (C) were also determined using particle size analyzer where the average hydrodynamic diameter was found to be 16+3 nm. These higher values were due to the light scattered by the core particle and the layers formed on the surface of the particles.
Further, as shown in figure 13, figure 14 & figure 15, Energy-dispersive X-ray (EDX) analysis spectrum for gold nanoparticles of the products produced in accordance with the examples (Al), (A2) & (A3) respectively were recorded in the spot-profile mode from one of the densely populated gold nanoparticles regions on the surface of film. Strong signals from Au atoms while weaker signals from C, O, Si, Cu and Ca atoms were observed. The overall particles charge in a particular medium is denoted as their zeta potential value which is also responsible for deciding the fate of stability. Here, synthesized gold nanoparticles in accordance with the examples (Al), (A2) & (A3) had 15 ± 2 MeV zeta potential values, which is sufficient to keep the particles away from aggregation and maintained the stability, moreover positive value also suggests that

hydrazide groups were successfully introduced onto the surface of nanoparticles.
Gold nanoparticles of formula (A), formula (B) and formula (C) are water dispersible, highly stable for more than 60 days at neutral pH with a size of less than 10 nm and zeta potential of 15 ± 2 MeV makes these nanoparticles very potential candidate for various biological/biomedical applications.
Stability Study: Effect of pH and time on stability of gold nanoparticles of formula (A), formula (B) and formula (C):
Stability of gold nanoparticles as produced in accordance with the examples (Al), (A2) & (A3) have been investigated by change in their surface plasmon resonance (SPR) band and fluorescence intensity at different pH (4.0 to 10.0) (Figure-16, 17 & 18 respectively). SPR band of gold nanoparticles as produced in accordance with the examples (Al)(CPH-AuNPs), (A2)(OMTRH-AuNps) & (A3)(CRTH-AuNps) show slight change at pH other than 7.0 and tend to agglomerate. It is noteworthy that when their agglomerated form is sonicated for 10-15 minutes they retain their originality with a negligible compromise in their SPR band and thereby size.
Also Figure 19, figure 20 and figure 21 show that No change in SPR band of the gold nanoparticles of formula (A), formula (B) and formula (C) at pH 7.0 and the same was recorded for the days 60, 120 and 120 days respectively.
Further, as shown in figures 22, 23 & 24 of the gold nanoparticles as produced in accordance with the examples (Al), (A2) & (A3) respectively, Surface Plasmon Resonance (SPR) band show the colour change of Gold solution from yellow to Ruby Red colour occur at 526nm,550nm and 526nm respectively that confirm the successful formation of gold nanoparticles.

(B) Silver nanoparticles as per examples (Bl), (B2) & (B3):
The synthesized silver nanoparticles of the compounds of formula (A)(CPH-AgNps), (B)(OMTRH-AgNps) and (Cj(CRTH-AgNps) as obtained in examples (Bl), (B2) & (B3) respectively, were characterized by UV-Visible spectroscopy, transmission electron microscopy (TEM) and particle size analyzer (PSA). The observations confirmed the high stability of gold Nanoparticle in aqueous solution over a long period of time and even at varied pH.
Characterization of Silver nanoparticles by particle size analyzer, Transmission Electron Microscope (TEM) and Energy Dispersive X-Ray (EDX):
A drop of dilute solution of aqueous nanoparticles as obtained from examples (Bl), (B2) & (B3) was placed on carbon coated copper grids and was dried in vacuum and directly observed in the TEM. The morphology and particles size of silver nanoparticles as obtained from examples (Bl), (B2) & (B3) shown in figure 25, figure 26 & figure 27 respectively, revealed that the particles are roughly spherical in shape and uniform in size, as well as, well dispersed with a narrow size distribution with an average particles size of 18±2 nm which can considered as less than 50nm.
Further, as shown in figure 28 & figure 29, Energy-dispersive X-ray (EDX) analysis spectrum for silver nanoparticles of the products produced in accordance with the examples (Bl) & (B2) respectively, were recorded in the spot-profile mode from one of the densely populated gold nanoparticles regions on the surface of film. The overall particles charge in a particular medium is denoted as their zeta potential value which is also responsible for deciding the fate of stability. Here, synthesized silver nanoparticles in accordance with examples (Bl) & (B2), had a 3 ± 2 MeV zeta potential value which is sufficient to keep the particles away from aggregation and maintained the stability, moreover positive value also suggests that

hydrazide groups were successfully introduced onto the surface of nanoparticles.
Stability Study: Effect of pH and time on stability:
Stability of silver nanoparticles obtained from examples (Bl}, (B2) & (B3) has been investigated by change in their SPR band and fluorescence intensity at different pH. According to the figures 30, 31 & 32, SPR band of silver nanoparticles obtained from examples (Bl), (B2) & (B3) respectively show negligible change at pH other than 7.0 for a day or two but silver nanoparticles tend to agglomerate after that. It is noteworthy that when their agglomerated form is sonicated for 15-20 minutes they retain their originality with a negligible compromise in their SPR band and thereby size.
As shown in figures 33, 34 & 35 of the silver nanoparticles as produced in accordance with the examples (Bl), (B2) & (B3) respectively, Surface Plasmon Resonance (SPR) band show the colour change of Silver solution from colourless to Yellow colour occur at 408nm, 415nm and 426nm respectively that confirm the successful formation of silver nanoparticles.
Further, no change in SPR band of silver nanoparticles obtained from examples (Bl), (B2) & (B3) at pH 7.0 was recorded up to 120 days which is shown in figure 36, 37 & 38 respectively.
APPICATION OF GOLD & SILVER NANOPARTICLES
Figure 39 & 40 shows application of Gold nanoparticles obtained from example Al(CPH-AuNps) as turn off fluorescent sensor. Gold nanoparticles have been investigated for its application as turn off fluorescent sensor for Hg(II) ions (Fig 39). A concentration of Hg(II) ions in the limit of 10 nM to 10 μM can be detected based on fluorescence quenching of the CPH-AuNps and it was also concluded from the spectroscopic data (Fig 40) that gold

nanoparticles possess excellent selectivity for Hg(II) ions over several metal ions like Pb(II), Cu(II), Cd(II), Mn(II), Zn(II) and Ni(II).
Figure-41 shows that using gold nanoparticles obtained from example A2(OMTRH-AuNps) as a selective and sensitive fluorescent probe, Cu(II) ions could be detected at a minimum concentration level of 1 nM in a facile way of fluorescence quenching i.e. by a turn off mechanism. Moreover, reversible simultaneous fluorescence recovery was observed when leucine was added in the same solution, which shows the turn off-on mechanism of gold Nanoparticles(Figure-42).
Figure-43 shows Fluorescence spectra of gold nanoparticles(CRTH-AuNps) obtained from example A3 on addition various amino acids (1 μM) at pH 7.0. Gold Nanoparticles(CRTH-AuNps) have been investigated for its application as turn off fluorescent sensor for phenylalanine amino acid. A concentration of phenylalanine in the limit of 1 nM to 0.9 μM can be detected based on fluorescence quenching.
Duly characterized silver nanoparticles obtained from example Bl(CPH-AgNps) were explored for their sensitivity and selectivity towards various metal ions by means of fluorescence quenching. It was found that fluorescent nanoparticles were selective and sensitive up to the detection limit of 10 μM for Fe(III) ions only(Fig-44).
As shown in figures-45 & 46, application of silver nanoparticles obtained from example B2(OMTRH-AgNps) and B3(CRTH-AgNps) as a simple, cost effective and sensitive fluorescent sensor for rapid detection of cadmium and lead respectively has been explored. Under optimum conditions, the fluorescence intensity of silver nanoparticles obtained from example B2 was inversely proportional to the cadmium concentration. Using silver nanoparticles as a

selective and sensitive fluorescent probe, cadmium can be detected at a minimum concentration level of 10-8M in a facile way of fluorescence quenching i.e. by a "turn off mechanism. The method has been successfully applied for determination of Cd(II) ions in ground water and industrial effluent waste water samples.
Gold nanoparticles of example Al(CPH-AuNps) and silver nanoparticles of example Bl(CPH-AgNps) were found to be the selective and sensitive fluorescent probe for L-Dopa and histidine, respectively (Figure 47 & 48). The minimum detectable limit for both L-Dopa and histidine was found at 10 nM by a facile way of fluorescence quenching i.e. by a turn off mechanism. Both the nanoparticles have also been studied for their antioxidant activity and interaction with DNA by UV-Visible spectrophotometry.
Furthermore, electrophoresis technique confirmed the interaction of EtBr intercalated CT-DNA and S-DNA with gold nanoparticles of example Al and silver nanoparticles of example Bl, respectively. The simplicity, sensitivity and specificity for the detection of amino acids by the said nanoparticles indicate that the synthesized nanoparticles can be used as nano biosensor, with a potential prospect in the biomedical analysis.
Interaction of gold nanoparticles of example Al(CPH-AuNps) and silver nanonaprticles of example Bl (CPH-AgNps) with CT-DNA and S-DNA:
Nanoparticles are well established test system to investigate DNA linking. For the investigation of the DNA mediated coupling of the nanoparticles, mainly absorption spectroscopy is employed. The absorption spectra of CT-DNA and S-DNA was recorded at 260 nm (Figure-49). The SPR band of CPH-AuNps (Al) was observed at 524 nm then, after conjugating with CT-DNA and with S-DNA it shifted towards higher wavelength at 545 nm (Figure-50a), whereas, in case of CPH-AgNps(Bl), after conjugating with CT-DNA and S-DNA,

wavelength shifted from 408 nm to 420 nm (Fig.50b). The successful interaction of the particles leads to a red shift and broadening of the UV-Visible spectrum as observed in the present case.
Antioxidant activity of nanoparticles:
Free radical is an unstable atom or molecule with an outer most electron unpaired and is highly reactive. The free radicals always strive to form a stable bond, by gaining or losing an unpaired electron. Nanoparticles of gold and silver based on reaction conditions are ready to accept/donate an electron to quench radicals
The DPPH is a stable and well characterized radical for evaluation of antioxidant potential of compounds. The DPPH is reduced by accepting the hydrogen or electron, the DPPH reducing ability of gold and silver nanoparticles was quantified spectrophotometrically by changing the DPPH colour from purple to yellow. A comparative study of antioxidant activity with standard antioxidant reference materials, quercetin and ascorbic acid (AA) were conducted. Although the antioxidant activity of CPH-AgNps and CPH-AuNps is slightly lower than that of standard antioxidant quercetin and ascorbic acid (AA), it is therefore, reasonable to propose that CPH-AuNps and CPH-AgNps hold the potential of their use as a good antioxidant agent (Fig. 51).
ADVANTAGES OF THE PRSENT INVENTION
Now, without limiting the scope of the present invention, advantages of the present invention may be provided as follows:
Calix[4]resorcinarene polyhydrazide of formula (A),
calix[4jresorcinarene tetrahydrazide formula (B) and formula (C) are used in the preparation of metal nanoparticles and the formed nanoparticles are having below mentioned applications:

Nanoparticles exhibit the electrical switching properties at a reasonably low voltage suggesting its potential application in nonvolatile random-access memory device or resistive random-access memory device (RRAM)."
Silver and Gold Nano particles of calix[4]resorcinarene polyhydrazide of formula (A), calix[4]resorcinarene tetrahydrazide formula (B) and formula (C) were found to be stable at room temperature, at different pH for long period of time. Further, nanoparticles are selective and sensitive fluorescent chemo sensors and bio sensor also.
The nanoparticles have shown good antimicrobial activity as well as interaction with DNA. Nanoparticles being stable in the aqueous system and of size 5± 2nm provides ample opportunity of their application in various biological systems.

We Claim:
1. Calix[4]resorcinarene hydrazides of formula (X).

2. Calix[4]resorcinarene hydrazides of formula (X) as claimed in claimed in claim 1 wherein formula (X) is calix[4]resorcinarene polyhydrazide of formula (A)

3. Calix[4]resorcinarene hydrazides of formula (X) as claimed in claimed in claim 1 where in formula (X) is calix[4]resorcinarene polyhydrazide of formula (B)


4. Calix[4]resorcinarene hydrazides of formula (X) as claimed in claimed in claim 1 where in formula (X) is calix[4]resorcinarene polyhydrazide of formula (C)

5. A process for the preparation of calix[4Jresorcinarene hydrazides of formula (X) may be provided as follows:
Suspending the desired compound selected from formula (4), formula (3) or formula (5) with hydrazine hydrate in a mixture of ethanol:toluene;
refluxing the mixture under stirring to give corresponding calix[4]resorcinarene hydrazide of formula (X);

optionally purifying the calix[4]resorcinarene hydrazide of formula (X) to obtain pure calix[4]resorcinarene hydrazide of formula (X).
6. The process as claimed in claim 5 wherein calix[4]resorcinarene hydrazide is selected from compounds of formula (A), formula (B) or formula (C).
7. A process for the preparation of calix[4]resorcinarene polyhydrazide of formula (A) comprises:
Suspending the compound of formula (4) with hydrazine
hydrate in a mixture of ethanohtoluene;
refluxing the mixture under stirring to give
calix[4]resorcinarene polyhydrazide of formula (A);
optionally purifying the calix[4]resorcinarene polyhydrazide of
formula (A) to obtain pure calix[4]resorcinarene polyhydrazide
of formula (A).
8. A process for the preparation of calix[4]resorcinarene
tetrahydrazide of formula (B) comprises:
Suspending the compound of formula (5) with hydrazine hydrate in a mixture of ethanol:toluene;
refluxing the mixture under stirring to give calix[4]resorcinarene tetrahydrazide of formula (B); optionally purifying the calix[4]resorcinarene tetrahydrazide of formula (B) to obtain pure calix[4]resorcinarene tetrahydrazide of formula (B).
9. A process for the preparation of calix[4]resorcinarene
tetrahydrazide of formula (C) comprises:
Suspending the compound of formula (3) with hydrazine hydrate in a mixture of ethanol: toluene;
refluxing the mixture under stirring to give calix[4]resorcinarene tetrahydrazide of formula (C);

optionally purifying the calix[4]resorcinarene tetrahydrazide of formula (C) to obtain pure calix[4]resorcinarene tetrahydrazide of formula (C).
10. CPH-AuNps (Gold nanoparticles) prepared using calix[4]resorcinarene polyhydrazide of formula (A).
11. CPH-AgNps (Silver nanoparticles) prepared using calix[4]resorcinarene polyhydrazide of formula (A).
12. OMTRH-AuNps (Gold nanoparticles) prepared using calix[4]resorcinarene tetrahydrazide of formula (B).
13. OMTRH-AgNps (Silver nanoparticles) prepared using calix[4]resorcinarene tetrahydrazide of formula (B).
14. CRTH-AuNps (Gold nanoparticles) prepared using calix[4]pyrrole octahydrazide of formula (A).
15. CRTH-AgNps (Silver nanoparticles) prepared using calix[4]pyrrole octahydrazide of formula (A).
16. A process for the preparation of calix[4]resorcinarene hydrazide metal nanoparticles comprises the steps of:
mixing aqueous solution of calix[4]resorcinarene hydrazide of formula (X) with aqueous solution of metal salt to get the reaction mass;
stirring it to obtain metal colloids in the reaction mass; carrying out centrifugation of the colloidal reaction mass to get metal nano particles derived from calix[4]resorcinarene hydrazide of formula (X).
17. The process as claimed in claim 16 wherein calix[4]resorcinarene
hydrazide is selected from the compounds of formula (A),
formula (B) or formula (C).

18. The process for the preparation of calix[4]resorcinarene hydrazide metal nanoparticles as claimed in claim 16 wherein ratio of mixing of calix[4]resorcinarene hydrazide and metal salt is 1:1 wt/wt.
19. The process for the preparation of calix[4]resorcinarene hydrazide metal nanoparticles as claimed in claim 16 wherein mixing is done at a temperature between 20°C to 35°C.
20. The process for the preparation of calix[4]resorcinarene hydrazide metal nanoparticles as claimed in claim 16 wherein metal salt in step (a) is selected from AgN03 or HAuCl4.
21. The process for the preparation of calix[4]resorcinarene hydrazide metal nanoparticles as claimed in claim 16 wherein centrifugation at 5000 rpm is done for three times.