SYNTHESIS OF TIN OXIDE PRECURSORS AND RELATED GERMANIUM AND LEAD COMPOUNDS

The goals of this study were to synthesize volatile tin(II) hexafluoro isopropoxide complexes for use as precursors to tin oxide or fluorine- doped tin oxide and to prepare related germanium(II) and lead(II) comp ounds. M(N(SiMe(3))(2))2 reacts with 2 equiv of R(f)OH (R(f) = CH(CF3) (2)) and 1 equiv of added amine, L, to give M(OR(f))(2)L (M = Ge, L py or H(2)NPh; M = Sn, L = HNMe(2) or py; M = Pb, L p-pyNMe(2)) in high yield. Alternatively, Sn(OR(f))(2)(HNMe(2)) can be prepared by reactin g Sn(NMe(2))(2) with R(f)OH. X-ray crystallographic studies of Ge(OR(f ))(2)(H(2)NPh) and Sn(OR(f))(HNMe(2)) show they are monomers with trig onal pyramidal geometries. An X-ray structure of the Pb compound shows it is the dimer [Pb(mu-OR(f))(OR(f))(p-pyNMe(2))](2). Pb(NMe(2))(2) r eacts with 3 equiv of R(f)OH to give [Me(2)NH(2)][Pb(OR(f))(3)], which an X-ray structure shows is the dimer {[Me(2)NH(2)][Pb(mu-OR(f))(OR(f ))(2)]}(2). Both Pb dimers are held together by weak dative Pb-O inter actions. Sn(N(SiMe(3))(2))(2) reacts with 2 equiv of R(f)OH in the abs ence of added amine to give amine-free Sn(OR(f))(2). By analogy to kno wn tin(II) alkoxide and related compounds, Sn(OR(f))2 is proposed to b e a dimer with two bridging alkoxide ligands. The tin compounds are vo latile solids, an important criterion for their possible use as conven tional tin oxide precursors in chemical vapor deposition processes.