Silicon halides fluorination

Higher silicon halides Si X +2 with n > 2 but of limited molecular weight have been known for a long time, above all from chlorine, but a few from bromine, and none from iodine. In the case of fluorine, some higher silicon fluorides derived from difluorosilylene have been recently discovered (see p. 60). 

Silicon halides can be easily prepared by the reaction of silicon or silicon alloys and the respective halogens (24). Fluorine and silicon react at room temperature to produce silicon tetrafluoride. Chlorine reacts with silicon exothermally, but the mixture must be heated to several hundred degrees centigrade to initiate the reaction (25). Bromine and iodine react with silicon at red heat. 

Halogens, halides. Hydrogen fluoride, hydrogen chloride, chlorine, fluorine, silicon tetrafluoride... 

Silicon, like carbon, is relatively inactive at ordinary temperatures. But, when heated, it reacts vigorously with the halogens (fluorine, chlorine, bromine, cmd iodine) to form halides and with certain metals to form silicides. It is unaffected by all acids except hydrofluoric. At red heat, silicon is attacked by water vapor or by oxygen, forming a surface layer of silicon dioxide. When silicon and carbon are combined at electric furnace temperatures of 2,000 to 2,600 °C (3,600 to 4700 °F), they form silicon carbide (Carborundum = SiC), which is an Importeint abrasive. When reacted with hydrogen, silicon forms a series of hydrides, the silanes. Silicon also forms a series of organic silicon compounds called silicones, when reacted with various organic compounds. 

Titanium can be etched in fluorine-, chlorine-, or bromine-containing gases, because all the halides are volatile. Chlorides and bromides have been studied to a great extent since they result in high selectivity over silicon- containing films, and do not promote staining on gold (77). 

Elements determined by indirect means bromine, chlorine, fluorine, iodine (although bromine, chlorine and fluorine can be determined by their metallic halide spectra), phosphorus, and silicon. 

Fluorination of the inorganic halide probably occurs in accordance with the following equation (e.g., with silicon tetrachloride) ... 

Although trimethyl(vinyl)silane undergoes the coupling reaction with aryl halides in the presence of TASF and a palladium catalyst as described in Section 1 (Eq. 3), those having an aliphatic substituent on vinyl fail to couple with aryl iodides under similar conditions, probably because they are not capable of affording pentacoordinate silicates efficiently owing to the electron-donating nature of the substituent. To assist the formation of the pentacoordinated intermediates, the methyl on silicon was replaced by fluorine [13]. The cou-... 

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