Disiloxanes disilanes

Disilane, hexamethyl-. See Hexamethyidisilane Disilicane. See Disilane Disiloxane, 1,3-diethenyl-1,1,3,3-tetramethyl-. See Divinyltetramethyidisiloxane Disiloxane, hexamethyl-. See Hexamethyidisiloxane Disiloxane, 1,1,2,2,2-pentamethyl-1-(2-phenylethyl)-. See Phenethyl disiloxane Disiloxane, 1,1,3,3-tetramethyl-. Seel,1,3,3-Tetramethyldisiloxane... 

The structural comparison (Fig. 3) with both the twofold tris(trimethylsilyl)methyl substituted acetylene and 1,4-benzene derivatives (Fig. 1) as well as with the literature data [6a] for hexa-kis(rm.butyl)disilane [6b] containing a SiSi bond elongated to 270 pm ( ), for the linear ( ) hexa-kis(rm.butyl)disiloxane [6c] or for di(tris(trimethylsilyl)silyl)zinc [6d] is based advantageously on a model in which the two substituent half-shells are separated along their central C3 axes by spacers of different lengths. 

Disilanes 43-48 are allowed to react with BTSP to give the corresponding disiloxanes (equations 70 and 71), and the results are summarized in Table 15 . Compounds 44-47 and 48a react with BTSP exothermally at or below room temperature, while 44 reacted slowly at room temperature, and 48b and 48c and hexamethyldisilane required more drastic reaction conditions. The eight-membered ring 48d does not react with BTSP. 

From silanes 52 are obtained, in high yield, the corresponding silanols 53, which react further to produce disiloxanes 56 and 58-60. Silanes 54 alkoxysilanes 55 and disilanes 57 give high yields of disiloxanes 56. Ozonolysis of tetraethylsilane yields initially acetaldehyde and trimethylsilyl hydroperoxide 61. The latter is partially converted to bis(triethylsilyl) peroxide 62, which is hydrolyzed to silanol 63 and hydrogen peroxide. The ozonolysis is of first order, both in regard to the silanes, and to ozone. The ozonolysis starts with formation of 64 followed by formation of the trioxide 65, which decomposes to acetaldehyde and hydroperoxide 61 (Scheme 14)79 80. 

The structures of PhSiFs (by electron diffraction), bis(l,8-naphthylene)-dichloro-disilane and -disiloxane (by X-ray difffaction), and MesGeCl (from microwave rotational spectra) have been determined. PhSiFj and Me GeCl are tetrahedral molecules. The structures of the two chlorosilanes are shown in Figure... 

Figure 17 The structures of bis(l,8-naphthylene)dichloro-disilane and -disiloxane (Reproduced by permission from J. Struct. Chem., 1975, 16, 144)...

Minor products from the direct reaction, all normally produced in amounts less than 1%, include SiCU, HSiCH, Me4Si, Me(Et)SiCl2, disilanes, especially Me2Si(Cl)Si(Me)Cl2 and (MeSiCl2)2, disiloxanes, CH4 and other hydrocarbons, and H2. The reaction effluent contains all of these, plus excess MeCl, and finely divided silicon particles containing up to 20% copper as well as other metals. These solids are separated, and usually treated to recover the copper. Unreacted MeCl is separated, purified, and recycled. The monosilane fraction is distilled out and then separated into its components by careful fractional distillation. The disilane fraction can also be distilled out, and may be upgraded into useful chloromonosilanes by cleavage reactions, as shown in equation (8). 

We also prepared hybrid alkane-co-silicone polymers from precursor blocks containing Si-H or Si-OMe moieties, respectively, and a simple disiloxane or disilane, again in wet conditions (Fig. 17b) [70]. The best results were obtained using the precursor M, since the co-reactant crossreacted readily with the methoxy... 

Reactions between (1) and disilanes containing fluorine atoms or possessing ring strain proceed readily at ambient temperature to generate the corresponding disiloxanes. Oxidation of... 

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