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Tin forms stannous fluoride, stannic fluoride, and fluorostannates. Stannous fluoride is a white solid with mp 215C. It is soluble in water ∼ 30–39% and up to 72–82% in anhydrous hydrogen fluoride. It is commercially prepared by the action of hydrogen fluoride on stannous oxide or metallic tin. Stannous fluoride is used widely in dentifrices and dental preparations because of its anticaries effect. Complexes of the type MSnF3, where M Rb, Cs, etc, were obtained from the molten mixture of SnF2 with NaF, Rb, and CsF. Stannic fluoride is a white solid that sublimes at 705C. It can be prepared from the reaction of fluorine, chlorine trifluoride, or bromine trifluoride with tin(II) or tin(IV) compounds. It acts as a Lewis acid to form many complexes. It is used in the manufacture of glasses. Stannous fluoroborate, Sn(BF4)2, is produced in an electrochemical cell and is used in electroplating. |
