Tin compounds are classified into two main groups; inorganic-tin and organo-tin compounds. The organo-tin compounds are defined as compounds in which at least one tin-to-carbon bond exist. But the inorganic-tin compounds do not contain carbon as the principal element. Inorganic-tin compounds are relatively simple in their molecular structure and, like tin itself, are not considered to be toxic. Tin atoms can replace carbon atoms in chemical compounds, and a great variety of organo-tin compounds are known.
INORGANIC TIN COMPOUNDS
The largest use for inorganic tin compounds is in electrolytes for plating tin and tin alloys. The more important plating chemicals are chlorides, sulfates, and fluoroborates in acidic electrolytes and stannates in alkaline solutions. Inorganic-tin compounds are divided into two series: stannous, or tin(II), compounds and stannic, or tin(IV), compounds.Chemically, tin exhibits valencies of 2 and 4. It resists attack by water but is dissolved by strong acids and alkalis. One of common compounds of tin(II) are stannous chloride (SnCl2) used in tin galvanizing, as a reducing agent in the manufacture of polymers and as a mordant in dyeing.; stannous oxide (SnO) employed in making tin salts for chemical reagents and for plating; and stannous fluoride (SnF2) is the additive in fluoride tooth-pastes. Inorganic tin chemicals are used as catalysts in a number of industrial processes. stannous octoate is the catalyst that produces the foaming action that turns the liquid plastic into a foamlike solid structure in the manufacture of polyurethane foam. Tin(IV) compounds of significance include stannic chloride (SnCl4) is widely used as a stabilizer for perfumes and as a starting material for other tin salts; and stannic oxide(SnO2) is a useful catalyst in certain industrial processes and a polishing powder for steel. Tin sulfide is used as a bronzing agent for wood colouring