Claims:The scope of the invention is defined by the following claims:

Claims:
1. The structure of Bromodimethylsilylbis(trimethylsilyl)methane comprising:
a) A distorted tetrahedral structure with the bromine atom away from the central carbon atom.
b) A silicon atom retains their tetrahedral configuration.
c) Extracting the copyright content from the watermarked image.
2. As per claim 1, Phenylselenolatodimethylsilylbis(trimethylsilyl)methane, that has the distorted tetrahedral structure with the SePh group away from the central carbon atom and silicon atom retains their tetrahedral configuration.
3. As per claim 1, synthesis of phenylselenolatodimethylsilylbis(trimethylsilyl)methane could be extended to sulphur and tellurium analogues to compare the reactivity pattern , Description:Field of the invention
The present invention is related with the synthesis and characterization of a new class of bis bulky silyl compound [(Me3Si)2 Me2SiBr) CH], [{bromodimethylsilyl}bis(trimethylsilyl)methane]. This invention is further extended to synthesize a new family of bulky silyl substituted ligands bearing chalcogen donors, [(phenylselenatodimethylsilyl)bis(trimethylsilyl)methane].
Background of the Invention
The structures of simple compounds, (Me3C)2CH2 (J. Marmur, [1961], J. Mol. Biol., 3, p 208), (Me3C)3CH (M.F. Reichmann et al., [1954], J.Am.Chem., 76, p 3047), (Me3Si)3CH (T. Fjeldberg et al., [1983], J. Mol. Struct., 99, p 295) in which two or three bulky groups are attached to a central carbon atom were studied by electron diffraction. A substantial number of novel type compounds have been isolated with the attachment of bulky ligand (Me3Si)3C – (trisyl) or the related ligand (Si Me2Ph)3C – (trisyl -type) to the metal centre (C. Eaborn et al. [2001], Dalton Trans., p 1541), (A. Asadi et al. [2005], J. Organomet. Chem., 690, p 944). Meanwhile, the attention has been focussed to functionalize the silicon atom with halide substituents, (Me2SiBr)3CH (C. Eaborn et al., [1983], J. Organomet. Chem., 252, p 281) that was studied by X ray diffraction as well. Therefore, the structure of the related species [(Me3Si)2(Me2SiBr) CH], could then be determine and studied by X ray diffraction.
Moreover, the trisyl ligand is being increasingly used in organometallic chemistry (US20010007909 A1), (W02014093772A1) often bestowing unusual properties due to the bulky ligand (G. Fritz et al. [1977], Anorg. Allgm. Chem., 430, p 121). Thus, it was of interest to synthesize the bromide derivative [(Me3Si)2(Me2SiBr) CH] and examine whether it would have even greater bulk as expected.
Chemists are largely motivated by the challenges in synthesizing organochalcogen compounds and to explore their application in novel organic synthesis. Keeping this in view, there is still in need to develop some rational approach towards the synthesis and characterization of a new family bulky silyl-substituted ligand containing chalcogen donor such as [(SiMe3)2(SiMe2SePh) CH]. There is distinct sparsity in the activity of bulky silyl ligands containing chalcogen donors, therefore the objective of the invention is to understand the unusual structures and reactivity pattern of this new family of bulky silyl substituted ligands containing chalcogen donors.
Summary of the invention
The present invention provides the synthesis of bromo derivative, [(Me3Si)2(Me2SiBr)CH] [{bromodimethylsilyl}bis(trimethylsilyl)methane] whose analytical, spectral and crystal structure data suggest a distorted tetrahedral structure.
In another aspect, the present invention provides a method for producing the novel compound (US 5233069A) [(SiMe3)2(SiMe2SePh)CH] of the invention. The method comprises the steps of reacting [{bromodimethylsilyl}bis(trimethylsilyl)methane] with sodium phenyl selenolate in the presence of solvent at room temperature.

Brief Description of Drawings
The invention will be described in detail with reference to the exemplary embodiments shown in the figures wherein:
Figure 1 Reaction of benzene at room temperature
Figure 2 Molecular structure of [(Me3Si)2(Me2SiBr)CH]
Detailed description of the invention
The present invention at first provides the synthesis of bromo derivative, [(Me3Si)2(Me2SiBr)CH] [{bromodimethylsilyl}bis(trimethylsilyl)methane] which was then characterised by analytical, spectral and X ray diffraction studies.
All the reactions were carried out under an argon atmosphere and the compounds were manipulated on a double manifold vacuum line by the use of standard Schlenk techniques. The solvent used for the reaction process were dried and distilled over sodium - potassium alloy (benzene, heptane) or sodium – benzophenone (Et2O, THF) and stored over a sodium or potassium mirror under argon. Solvents and solutions were transferred by cannula under argon pressure, the cannula was kept in an oven and flushed with argon before use. Glass syringes were used to transfer air and moisture sensitive liquid compounds. For transfer of solids, two Schlenk tubes were connected to a bent tube which allowed the compound to be shaken from one into the other. In case of small amount, a Y-shaped adapter was used. The extra opening makes it possible to use a long spatula to do the actual transfer.
The precursor bis(trimethylsilyl)bromomethane was prepared from literature method by the reaction of of CHBr3, Me3SiCl and nBuLi in THF at –78 °C that was characterized by GC-MS and NMR spectroscopy. It is further reacted with HMe2SiCl and Mg turnings in THF at room temperature to give the hydride, [(Me3Si)2(Me2SiH) CH]. The bromination of the hydride (Me3Si)2(Me2SiH) CH in CCl4 gives the compound bromodimethylsilylbis(trimethylsilyl)methane, [(Me3Si)2Me2SiBr)CH] 1. The compound was obtained in good yield. The compound 1 is readily isolated as colourless crystalline solid by removing the solvent under reduced pressure. It is soluble in hydrocarbon solvents. Elemental analysis agreed well with the above formulation. The compound 1 is moisture sensitive and is easily hydrolysed. Characterization has been made by multinuclear NMR and single crystal X-ray diffraction studies.
The compound [{phenylselenatodimethylsily}lbis(trimethylsilyl)methane], [(Me3Si)2(Me2SiSePh)CH] 2 has been synthesized by the reaction of sodium phenyl selenolate, NaSePh (obtained from the triethylborohydride reduction of diphenyl diselenide, Ph2Se2) with the bromide, [(SiMe3)2(SiMe2Br) CH] in benzene at room temperature in good yield (figure 1). The compound 2 is readily isolated as a light-yellow oil under reduced pressure. It is soluble in hydrocarbon solvents. Elemental analysis agreed well with the above formulation. Characterization has been made by analytical and multinuclear NMR.
The invention will be further illustrated by the preparation of the following precursors. Preparation of Bis(trimethylsilyl)bromomethane, (Me3Si)2CHBr: A solution of CHBr3 (32 cm3, 0.37 mol; washed free of ethanol and dried) in THF (300 cm3) and Me3SiCl (96 cm3, 0.75 mol) were stirred with mechanical stirrer at –78°C. A 2.5 M nBuLi in hexane (300 cm3, 0.75 mol) was taken in dropping funnel of capacity 300 cm3 which was also cooled to –78 °C. Drop wise addition of nBuLi took over 5hr period maintaining –78°C. After addition, the mixture was allowed to rise to room temperature and continue overnight stirring with the bubbler open for flow of argon to yield a dense colorless precipitate. Ice was added to the precipitate to neutralize excess of BuLi. The organic layer was separated, dried over anhydrous MgSO4 and the solvent was evaporated. Fractional distillation of the residue gave (Me3Si)2CHBr (Yield: 32.7 g, 37%; b.p.75°- 80°C/ 20 mm Hg) which was characterized by GC-MS and NMR spectroscopy.
GC-MS: The purity of the product was assessed by GC-MS which showed 95% area of the main peak in the chromatograph corresponding to the following ion masses.
MS: m/z, (%): 238(5%) [M]+, 223(30%) [M–Me] +, 195(8%) [M−Me−Si] +, 150(15%) [M−Me−Si−H2SiMe] +, 137(15%) [M−Me−Si−H2SiMe−CH] +, 85(76%) [CSiMe3] +, 73(100%) [SiMe3,], 59(50%) [SiMe2H], 43(35%) [SiMe]+, 28(3%) [Si] (Fig 2.1 (a-c)).
1H NMR (CDCl3, 300 MHz): δ 2.15 (s, 1H, CH), 0.16 (s, 18 H, Me3Si)
13C {1H} NMR (CDCl3, 300 MHz): δ – 0.57(s, CH), 27.5 (s, SiMe3).
29Si {1H} NMR (CDCl3, 300 MHz): δ 3.81 (s, SiMe3)

Hydridodimethylsilyl)bis(trimethylsilyl)methane, [(Me3Si)2(Me2SiH)CH]: To a three necked 1L flask, 3.5 g of Mg turnings were transferred and the flask was flame dried. It was then stirred under argon for weekend to activate the magnesium. THF (300 cm3) and HMe2SiCl (16 cm3, 0.137 mol) were added and mixed in the flask. The compound, (Me3Si)2CHBr (32.7 g, 0.137 mol) diluted with 50 cm3 THF were added drop wise from the dropping funnel. The reaction is exothermic so cooling is required. The mixture after addition was stirred overnight at room temperature and refluxed for 2h. It is allowed to cool at room temperature and hydrolyzed with 200 cm3 water (or ice). The aqueous layer was separated and washed twice with petroleum ether (50 cm3). The organic fraction combined, dried over anhydrous MgSO4 overnight and solvent removed in vacuo, to leave a pale-yellow liquid. Fractional distillation of the residue gave [(Me3Si)2(Me2SiH)CH (Yield: 16.7g, 56%, b.p. 72°−74 °C/ 10 mmHg).
GC-MS: The purity of the product was assessed by GC-MS which showed 96% area of the main peak in the chromatograph corresponding to the following ion masses.
MS: m/z(%): 218(8%) [M]+, 217(20%) [M–H]+, 203(98%) [M–Me]+ 129(100%) [M−Me−SiMe3H]+, 115(35%) [M−Me−SiMe3H−CH2]+, 85(10%) [CSiMe3]+, 73(40%) [SiMe3], 59(50%) [SiMe2H], 43(20%) [SiMe]+ .
1H NMR (CDCl3, 300 MHz): δ – 0.796 (s, 1H, CH), 0.096 (s, 18 H, Me3Si), 0.167 (d, 6H, Me2Si, J 3.7 Hz), 4.10 (hept, 1H, SiH, J 3.7 Hz).
13C {1H} NMR (CDCl3, 300 MHz): δ – 0.63 (SiMe2), 1.95 (CH, DEPT 90), 2.40 (SiMe3)
29Si {1H} NMR (CDCl3, 300 MHz): δ 0.26 (SiMe3) and – 15.57 (SiMe2).
29Si (Proton-coupled) NMR (CDCl3, 300 MHz): 1J(29Si1H),182.5Hz (d), 2J(29Si1H), 10.0 Hz (d) and 2J(29Si1H), 16.8 Hz (hept).
Preparation of the bromo derivative, [(Me3Si)2(Me2SiBr)CH] from the precursor [(Me3Si)2(Me2SiH)CH] A solution of Br2 (12.15 g, 0.076 mol in CCl4 (50 cm3)) was added drop wise during 1h to a solution of [HC(SiMe3)2(SiMe2H)] (D. Seyferth and H. Lang, [1991], Organometallics, 10, 551). (16.70 g, 0.076 mol) in CCl4 (30 cm3) at 0°C, and the resulting orange solution was stirred at room temperature for 18h. The solvent was removed and the orange residue distilled (b.p 54°C/10–3) to give a colourless oil that crystallized on standing, mp 42°C. Yield: 16.704 g (75%). Anal. Calc. for C9H25BrSi3(%): C, 36.36; H, 8.41; Found: C, 36.65; H, 8.60.
MS: m/z(%): 281(100%) [M–Me]+, 217(88%) [M–Br]+, 203(15%) [M–Br–CH2]+, 129(75%) [M–Br–CH2–H–SiMe3]+, 73(45%) [SiMe3], 59(14%) [SiMe2H], 45(7%) [SiMe2H–CH2]+.
IR (Nujol, CsBr plates) (cm-1): 1251 m, δ(C−H); 1030 w; 845 vs, 730 w ρ(CH3)(Si); 670 w, as (SiC); 610 vw, s (SiC); 429 s,  (Si−Br).
1H NMR (300 MHz, C6D6): δ – 0.37 (1H, s, CH), 0.15 (18H, s, SiMe3), 0.54 (6H, s, SiMe2).
13C{1H} NMR (300 MHz, C6D6): δ 8.19 (Si3C, 1J(13Cmethine–1H) 100.11Hz), 3.16 (SiMe3, 1J(13Cmethyl–1H) 118.78 Hz), 7.82 (SiMe2), 1J (13Cmethyl–1H) 121.29 Hz).
29Si{1H} NMR (300 MHz, C6D6): δ – 0.37 (SiMe3); 24.69 (SiMe2Br).

X-ray Structure Determination: Colourless crystals were obtained using vacuum sublimation at 65°C. The crystal size is 0.4x0.2x0.2 mm3. The crystal system is monoclinic with space group P21/c(No.14) and cell dimensions, a = 8.8476(4) Å, b = 14.8285(9) Å, c = 12.2137(5) Å, α = 90°, β = 104.038°, γ = 90°. Intensities for +h+k+l reflections were measured for 2994 unique reflection with I>2σ(I). The crystal structure of [(Me3Si)2(Me2SiSePh)CH] is given in figure 2.
Diphenyldiselenide, Ph2Se2: To a solution of phenylmagnesium bromide [prepared from bromobenzene (19.0 g, 121.5 mmol) and magnesium powder (2.9 g, 121.5 mmol) in anhydrous ether (70 cm3)] was added selenium powder (9.6 g, 121.4 mmol) at room temperature (K. B. Sharpless and M. W. Young, J. Org. Chem., [1975], 40, 1974). The mixture was vigorously stirred for 3 h and then poured over a mixture of ice-cold water (500 cm3) and concentrated HCl (18.7 cm3). The aqueous layer was removed and the product was extracted with ether. To this dark orange extract, 80 cm3 of ethanol and 1.0 g KOH were added and left overnight. The yellow slurry was filtered, washed several times with cold 95% ethanol and dried in vacuum. Yield: 67%; m.p. 63ºC (lit value 63-65 ºC).
Analysis: Found: C, 40.8; H, 3.3; Se, 53.7%; Calc. for C12H10Se2: C, 41.6; H, 3.5; Se, 54.8%.
MS: m/z (%) 314(56%) [M]+, 234(35%) [M–Se] +, 157(90%) [M–SePh]+, 77(100%) [C6H5]+, 51(62%) [C6H3]+
1H NMR (300 MHz, CDCl3): δ 7.50 (d, J(HH) 7.5 Hz, 4H, o-Ph); 6.85-6.87 (m, 6H, m- and p-Ph).
13C {1H} NMR (300 MHz, CDCl3): δ 131.70 (i-C), 129.37 (o-C), 128.30 (m-C), 127.75 (p-C).
77Se {1H} NMR (300 MHz, CDCl3): δ 459.71 (SePh).
Preparation of NaSePh: Diphenyl diselenide (1.56 g, 4.9 mmol) was dissolved in diethyl ether (60 cm3), and sodium triethylborohydride (10 cm 3 of a 1.0 M solution in THF, 10 mmol) was added by syringe. The yellow solution colour disappeared within seconds. The colourless solution was stirred for 30 min and taken to dryness to give a white solid of NaSePh [U. Schubert and C. Steib, J. Organomet. Chem., [1982], 238, C1]. Preparation of [(Me3Si)2(Me2SiSePh)CH] from the bromo derivative: To the benzene suspension of NaSePh (1.32 g, 7.40 mmol was added dropwise through cannula a benzene solution of [(SiMe3)2(SiMe2Br)CH] (2.0 g, 6.75 mmol) and the mixture was stirred overnight. The solvent was removed completely in an external trap and then extracted with hexane. The solution was filtered to remove NaBr and the solvent stripped off under reduced pressure to give a light-yellow oil. Yield: 3.25 g (80%).
Anal. Calc. for C15H30Si3Se(%): C, 48.13; H, 8.02; Found : C, 48.01; H, 7.84.
MS: m/z(%): 374(10%) [M]+, 359(50%) [M–Me]+, 282(20%) [M–Me–Ph]+, 217(85%) [M–SePh]+, 201(15%) [M–SePh–CH4]+, 187(7%) [M–SePh–CH4–CH2]+, 129(100%) [M–SePh–CH4–CH2–SiMe2]+, 73(75%) [SiMe3], 59(20%) [SiMe2H], 45(10%) [SiMe2H–CH2].
1H NMR (300 MHz, C6D6): δ–0.38 (1H, s, CH), 0.19 (18H, s SiMe3), 0.38 (6H, s, SiMe2), 7.57 (2H, d, Ph, J(HH) 8 Hz), 6.95 (3H, d, Ph, J(HH) 8 Hz);
13C{1H} NMR (300 MHz): δ 3.54 (SiMe3), 4.92 (SiMe2), 5.59 (CH), 126.83 (p-C), 127.47 (m-C), 129.01 (o-C), 137.42 (i-C);
29Si {1H} NMR (300 MHz, C6D6): – 0.33 (SiMe3), 13.736 (SiMe2), 1J(29Si77Se) 108.4 Hz ;
77Se {1H} NMR (300 MHz, C6D6): 112.268 (SePh).