Stereochemical and biochemical aspects of some organoboron complexes of sulphur donor ligands

Abstract

Synthetic, structural and biochemical aspects of some organoboron complexes of sulphur containing ligands having ONS and SNNS donor systems have been described. The ligands were prepared by the condensation of 1-phenyl-1,3-butanedione, 2,4-pentanedione, diphenylethanedione, 2,3-butanedione, ethanedial and 1,4-benzenedialdehyde with 2-mercaptoaniline. The unimolar reactions between phenyl-boronic acid and these thio-ligands have produced Ph.B (ONS) and Ph.B. (SNNS) type of biologically active complexes. These have been characterized by elemental analysis, molecular weight determinations, and conductivity measurements. Based on UV, IR, 1H NMR, 13C NMR and 11B NMR spectral studies, a tetracoordinated state of boron has been established in all the derivatives. The ligands and their corresponding organoboron complexes have been tested in vitro against a number of pathogenic fungi and bacteria and found to possess remarkable fungicidal and bactericidal properties.