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

Silicothio-urea, SiS(NH2)2

Silicothio-urea, SiS(NH2)2, is formed by the action of ammonia on silicon thiobromide by a reaction analogous to that by which the corresponding carbon compound is formed:

SiSBr2 + 4NH3 = SiS(NH2)2 + 2NH4Br.

Silico-urea is not known, for no simple silicon oxyhalide, SiOX2, exists from which it could be prepared.

Silicothio-urea differs from its carbon analogue in being decomposed by water; hence the reaction for its preparation is carried out in anhydrous solution, as follows: Silicon thiobromide is dissolved in benzene, and dry ammonia is passed into the solution at low temperature, when silicothio-urea separates, together with ammonium bromide. Liquid ammonia is employed to dissolve the latter, and the silicothio-urea then remains as a white powder, which slowly decomposes at atmospheric temperature, evolving ammonia and hydrogen sulphide.

Water hydrolyses this compound into silicic acid, ammonia, and hydrogen sulphide. It possesses feebly basic properties, and forms salts with the halogen hydracids.

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