SYNTHESIS, SPECTROSCOPIC AND POLAROGRAPHIC STUDIES OF DIBUTYLTIN(IV) COMPLEXES OF SCHIFF-BASES DERIVED FROM 2-AMINOPHENOL

A series of dibutyltin(IV) complexes of Schiff bases derived from 2-am inophenol and benzaldehyde (HL1), anisaldehyde (HL2), 2-furfural (HL3) , acetophenone (HL4), benzylmethyl ketone (HL5), benzil (HL6), salicyl aldehyde (H2L7), 2-hydroxy-1-naphthaldehyde (H2L8) and 2-hydroxyacetop henone (H2L9) have been synthesized by the reaction of dibutyltin(IV) oxide with the preformed Schiff bases in 1:1 or 1:2 molar ratios in be nzene with azeotropical removal of water. The analytical data are in a greement with the proposed stoichiometries of the complexes. Molar con ductance values of the complexes (10(-3) M) in methanol indicate their non-electrolytic nature. Cis-trigonal bipyramidal or trans-octahedral geometries have been proposed for the complexes Bu2SnL2 (where HL = H L1 to HL6) and Bu2SnL (where H2L = H2L7 to H2L9), respectively, on the basis of electronic, infrared, far-infrared, H-1, C-13 and Sn-119 NMR , and Sn-119 Mossbauer spectral studies. All the Schiff bases and thei r dibutyltin complexes undergo reduction in the range -0.28 V to -2.5 V and their polarographic reduction is diffusion controlled and irreve rsible.