BIS(TRIPHENYLTIN) CHALCOGENIDES AS CONVENIENT PRECURSORS TO PHASE-PURE BINARY SEMICONDUCTORS

Bis(triphenyltin) chalcogenides, (Ph3Sn)2X (X = S, Se, and Te), were s ynthesized in good yield from Ph3SnCl and anhydrous Na2X made from ele mental Na and X with a catalytic amount of naphthalene in THF. When he ated to relatively modest temperatures (above 300-degrees-C) under an inert atmosphere, it is observed that these compounds undergo a series of phenyl migrations in the condensed (liquid) state. This pyrolysis results in the loss of tetraphenyltin and diphenylchalcogen as ''volat ile'' byproducts while leaving behind an inorganic powder. These powde rs are characterized by X-ray diffraction and found to be phase pure a nd highly crystalline SnS, SnSe, or SnTe. Combustion analysis detects less than 1% carbon contamination after rinsing with common solvents. Scanning electron micrographs show the powders to be polycrystalline a gglomerates having platy (SnS and SnSe) or cubooctahedral (SnTe) habit s.