SYNTHESIS, REACTIONS AND SPECTROSCOPIC STUDIES OF SOME NOVEL HETERO (BI AND TRI)METAL ALKOXIDES OF TIN(IV) WITH NIOBIUM AND TANTALUM

Novel (chloro)isopropoxo niobates and -tantalates of tin(IV) with the formulae Cl4-nSn{M(OPri)6}n, (n = 1 - 3) have been synthesized by the reactions of SnCl4 with an appropriate potassium hexaisopropoxometalla te, KM(OPri)6 (M = Nb/Ta) in the required molar ratios. These chloro p recursors have been used to obtain derivatives of the types (RO)2Sn{M( OPri)6}2 (R = Me, Pr(i), Bu(t)), {Ta(OPri)6}2Sn{Nb(OPri)6}2 and {Al(OP ri)4}ClSn{Nb(OPri)6}2 by the replacement reaction of the chloride with appropriate potassium alkoxide or isopropoxometallate. Characterizati on of these novel complexes has been carried out on the basis of eleme ntal and alkoxo group analyses, IR and multinuclear (H-1, C-14, Al-27 and Sn-119) NMR data and molecular weight studies.