Synthesis, characterization, structures, and DFT study of zinc(II) complexes with tributylphosphine chalcogenides

Abstract

Four new zinc(II) complexes of the type [ZnCl2(n-Bu3PE)2] (E = O ( 1 ), S ( 2 ), Se ( 3 ) or Te ( 4 )) have been synthesized from zinc(II) chloride and the ligands n-Bu3PE giving yields of 56-88%. The adducts were characterized by multinuclear (31P, 13C and 77Se) NMR, conductivity, IR spectroscopy and by X-ray analyses. The zinc complexes 1 – 4 are comprised of two ligands coordinated to the metal centre in a distorted tetrahedral arrangement. The P=E bond lengths of 1.497(7) (E = O), 2.000(4) (E = S) and 2.178(2) Å (E = Se) in these complexes are slightly elongated compared to those in the free ligand. In addition, a DFT/B3LYP theoretical study on the geometry optimization of the title ligands and their zinc complexes has been carried out in order to support and complement the experimental data and to further investigate the nature of the chalcogenide-metal interaction. The results show good agreement between the experimental and theoretical data.