Facile Incorporation of Bu3Sn(IV) into Sterically Congested Schiff Bases of Heterocyclic β-Diketones: Synthetic Route and Structural Considerations Based Upon Multinuclear (1H, 13C and 119Sn) NMR studies

A series of new tributyltin(IV) complexes derived from sterically congested Schiff bases of heterocyclic beta-diketones possessing the general formula Bu3SnL [where LH = RC:ZC:C(OH)N(C6H5)N:CCH3, with R = -CH3, -C6H5, -C6H4Cl(p) and Z = >NC6H5, >NC6H4Cl(m), >NC6H4Cl(p)] was prepared by the interaction of Bu3SnCl with sodium salt of sterically congested Schiff bases of heterocyclic beta-diketones in 1:1 molar ratio in dry refluxing THF. These complexes were found to be monomeric in nature as revealed by molecular weight measurements. The structures of these complexes were suggested on the basis of elemental analyses, molecular weight measurements and spectral [IR and NMR (H-1, C-13 and Sn-119)] studies. These tributyltin(IV) complexes possess pentacoordinated tin centres as revealed by Sn-119 NMR spectral studies and a distorted trigonal bipyramidal geometry may be suggested for these derivatives with the help of 119Sn NMR spectral data.