Spectral analysis of μ-bridging coordination in triphenyl Sn(IV)-Al(III)-μ-oxoisopropoxide derivatives of alkylpyruvate aroylhydrazone: Interpretation of pharmacophore geometries

Abstract

Triphenyl Sn(IV)-A(lII)-µ-oxoisopropoxide derivatives having different (NOONO and OONO) backbones were obtained by the reaction of triphenyltin acetate and aluminium isopropoxide with corresponding ligand. Through manipulation of reaction stoichiometry, varieties of coordination compounds featuring µ-bridging coordination were obtained. ¹¹⁹Sn NMR spectra of Ph₃SnOAl(OPrⁱ)L and Ph₃SnOAl(L)₂ exhibit a single resonance, in solution, which is a characteristic of four-coordinated triphenyl complex. There are quite close structural and architectural similarities between both series of complexes. Physicochemical analysis confirmed the formation of Ph₃SnOAl(OPrⁱ)L and Ph₃SnOAl(L)₂ derivatives. Both the derivatives of triphenyl Sn(IV)-Al(III)-µ-oxoisopropoxide showed tetra- and penta- coordination of metal centres with distorted tetrahedral and distorted trigonal-bipyramidal geometries for Sn(IV) and Al(III) respectively. These central metal ions are capable of organizing surrounding atoms to achieve pharmacophore geometries by the variation of architectural elements of concerned ligands which are not readily and rapidly achieved by other means. Five complexes from each series were screened for their anti-fungal and antibacterial properties.