Synthesis and characterization of mercury(II) mixed ligands complexes derived from 5-(4-pyridyl)-1,3,4-oxadiazole-2-thione with tertiary phosphines ligands

And Shihab A O Ahmed,Saleh A Ahmed,Ahmed S M Al-Janabi

doi:10.32894/kujss.2017.124913

Abstract

Many new mixed ligand mercury complexes have been synthesized with LH = 5(4-pyridyl)-1,3,4-oxadiazole-2-thione and tertiary phosphines as co-ligands. The compounds have been characterized by elemental analyses, IR, molar conductivity, and NMR spectroscopy. In the binuclear complexes (2-5), both Hg atoms have tetrahedral geometry, the Hg atom bonded to three halide ions and one thione ligand (LH) through the sulfur atom. The complex (6) show that thionlate ligand(L) is coordinated as monodentate through the sulfur atom. The bis(diphenylphosphino)methane (dppm) behave as bidentate bridging ligand to bonded two Hg(II) ions in the complex (7), Whereas in the complexes (7-10), the thionlate ligand bonded as a monodentate fashion via the sulfur atom, while the diphosphines ligands coordinated as bidentate chelating ligands, and the geometry around the Hg center ion is tetrahedral. And in the complexes (11 and 12), the phosphine bonded as monodentate ligand, and the thionlate bonded via the sulfur atom as monodentate to give tetrahedral complexes.

Highlights

The reaction of metal ions with heterocyclic thiones has been the subject of several investigations as these ligands Contain chemically active groups [-N(H)C(=S)- ↔ -N=C(-SH)-], and are useful model compounds for sulfur containing analogues of heterocyclic bases[1,2,3,4,5]
The ligand (Hpot) behaves as a monodentate neutral ligand coordinated through the sulfur atom for Hpot ligand
Whereas the treatment of ethanolic solution of Hg(oAc)2 with Hpot ligand present few drops of the Et3N gave Complex of the type [Hg(pot)2], and the anionic ligand(pot ) behave as monodentate bonded to mercury ion through the sulfur atom.(See Fig. 1)

Summary

INTRODUCTION

The reaction of metal ions with heterocyclic thiones has been the subject of several investigations as these ligands Contain chemically active groups [-N(H)C(=S)- ↔ -N=C(-SH)-], and are useful model compounds for sulfur containing analogues of heterocyclic bases[1,2,3,4,5]. Heterocyclic -2-thione bind to a metal in several ways, leading to formation of monomeric or polymeric complexes [1,2,3,4,5,6,7,8,9,10,11,12]. The aim of the present work, preparation of new mercury(II) complexes with 5-(4-pyridyl)-1,3,4-oxadiazole-2-thione (Hpot) ligand and tertiary diphosphines as co-ligands, and characterization of its. The 1H NMR spectra were recorded on Varian unity 500 spectrometer with DMSO-d6 as solvent and Me4Si as internal reference. 31P NMR spectra were recorded on Gemini 2000 spectrometer with DMSO-d6 as solvent and H3PO4(85%) as external reference. Element analyses were measured at the Al-Bayt University- Jordan

Starting materials

Results and discussion

IR SPECTRA

Conclusions & Recommendation