Chemical elements
    Physical Properties
    Chemical Properties
      Silicon Tetrahydride
      Silicon Tetrafluoride
      Hydrofluosilicic Acid
      Silicon Subfluoride
      Silicon Tetrachloride
      Silicon Tetrabromide
      Silicon Tetra-iodide
      Mixed Halides of Silicon
      Halogen Derivatives of Silico-ethane
      Halogen Derivatives of Silicopropane
      Halogen Derivatives of Silicobutane
      Halogen Derivatives of Silicopentane and Silicohexane
      Silicon Oxychlorides
      Silicon Dioxide
      Silicoformic Anhydride
      Silico-oxalic Acid
      Silicomes-oxalic Acid
      Silicon Disulphide
      Silicon Monosulphide
      Silicon Oxysulphide
      Silicon Thiochloride
      Silicon Thiobromide
      Silicon Chloroitydrosulphide
      Silicon Selenide
      Silicon Tetramide
      Silicon Di-imide
      Silicon Nitrimide
      Siliconitrogen Hydride
      Silicon Nitrides
      Crystalline Silicon Monocarbide
      Silicon Dicarbide
      Silicon Carboxide
      Borides of Silicon
    PDB 1fuq-4ehr

Silicofluoroform, SiHF3

The other three compounds of the type SiHX3 are formed by the action of the halogen hydracid on silicon; silicofluoroform, however, has not been prepared in this way, but is derived from silicochloroform by the replacement of its chlorine by fluorine. This may be done by heating the latter substance to 220° C. with tin tetrafluoride or to 100°-120° C. if titanium tetrafluoride is employed:

4SiHCl3 + 3TiF4 = 4SiHF3 + 3TiCl4.

The operation is carried out in a sealed copper flask or gun-barrel; and silicofluoroform is formed as a colourless gas which on strong cooling condenses to a liquid boiling at -80° C., from which a crystalline solid melting at -110° C. can be obtained. The vapour density of silico-fluoroform (air = 1) has been found to be 3.02, the theoretical value being 2.99.

Gaseous silicofluoroform is not very stable, but decomposes, slowly at atmospheric temperature, quickly on heating to 420° C. in accordance with the reaction: 4SiHF3 = 3SiF4 + 2H2 + Si.

It burns with a bluish flame, producing amorphous silicic acid, and forms an explosive mixture with air. Water and dilute alkalis decompose the gas thus:

2SiHF3 + 4H2O = Si(OH)4 + H2SiF6 + 2H2;

absolute alcohol produces, similarly, ethylorthosilicate:

2SiHF3 + 4C2H5OH = Si(OC2H5)4 + H2SiF6 + 2H2

(cf. reaction with silicochloroform), while ether yields the ester of the corresponding acid, orthosilicoformic acid:

SiHF3 + 3(C2H5)2O = SiH(OC2H5)3 + 3C2H5F.

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