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Plastics Properties and Testing
Published in Manas Chanda, Plastics Technology Handbook, 2017
Silicon-Containing Groups. Polymeric organosilicon compounds are commonly referred to as silicones, the most widely used silicone resin being polydimethylsiloxane, with the general formula –[–Si(CH3)2–O–]–. Methyl groups attached to a silicon atom undergo the same C–H stretching and bending vibrations as a CH3 attached to a carbon atom, but the positions of the bands for a Si–CH3 group are different from those for a C–CH3 group, because of electronic effects. The absorption attributed to the umbrella mode (symmetric bend) vibration of the Si–CH3 group produces a very intense band at 1260 ± 5 cm−1, and when a silicon atom has two methyl groups attached to it, denoted as Si(CH3)2, there appears a strong methyl rocking mode band at 800 ± 10 cm−1. The pattern of bands in the spectrum of polydimethylsiloxane is very characteristic—a series of four intense bands between 1200 and 800 cm−1 (see Figure 3.94c). Few other materials give rise to this pattern. The band attributed to the Si–H group occurs at about 2200 cm−1 and is exceedingly prominent. The absorption owing to the Si–O linkage, which forms the backbone of silicone resins, occurs between 1100 and 1000 cm−1, producing a broad, complex, and intense band.
Toxicological Chemistry of Chemical Substances
Published in Stanley Manahan, Environmental Chemistry, 2017
Silicon tetrachloride, SiCl4, is the only industrially significant compound of the silicon tetrahalides, a group of compounds with the general formula SiX4, where X is a halogen. The two commercially produced silicon halohydrides, general formula H4−xSiXx, are dichlorosilane (SiH2Cl2) and trichlorosilane, (SiHCl3). These compounds are used as intermediates in the synthesis of organosilicon compounds and in the production of high-purity silicon for semiconductors. Silicon tetrachloride and trichlorosilane, fuming liquids that react with water to give off HCl vapor, have suffocating odors and are irritants to eye, nasal, and lung tissue.
Toxicological Chemistry of Chemical Substances
Published in Stanley E. Manahan, Environmental Chemistry, 2022
Silicon tetrachloride, SiCl4, is the only industrially significant compound of the silicon tetrahalides, a group of compounds with the general formula SiX4, where X is a halogen. The two commercially produced silicon halohydrides, general formula H4−xSiXx, are dichlorosilane (SiH2Cl2) and trichlorosilane, (SiHCl3). These compounds are used as intermediates in the synthesis of organosilicon compounds and in the production of high-purity silicon for semiconductors. Silicon tetrachloride and trichlorosilane, fuming liquids that react with water to give off HCl vapor, have suffocating odors and are irritants to eye, nasal, and lung tissue.
Rhodium(I) complexes with N-heterocyclic carbene ligands: synthesis, biological properties and catalytic activity in the hydrosilylation of aromatic ketones
Published in Journal of Coordination Chemistry, 2021
Naceur Hamdi, Ichraf Slimani, Lamjed Mansour, Faisal Alresheedi, Ismail Özdemir, Nevin Gürbüz
Hydrosilylation is a vital industrial process which is employed to synthesize polysiloxanes and polysilanes, inter alia [31]. Moreover, it is employed in the conversion of ketones to secondary alcohols [32]. Generally, the term hydrosilylation refers to the addition of hydrosilanes to double and triple bonds within the laboratory. Hydrosilylation could be convenient to make a range of organosilicon compounds. The evolution of various hydrosilylation catalysts has already been summarized [33].