Structure and thermal properties of a tungsten sulfide cluster with thiourea ligands

Abstract

The reaction of [W₃S₄(H₂O)₉]⁴⁺ with thiourea (tu) in hydrochloric acid produces a new cluster complex [W₃S₄(tu)₈(H₂O)]Cl₄∙2H₂O containing coordinated thiourea. The complex is characterized by elemental analysis, thermogravimetry, IR, NMR, UV-Vis spectroscopy, and mass spectrometry. The crystal structure is determined by X-ray analysis. The thermal decomposition of [W₃S₄(tu)₈(H₂O)]Cl₄∙2H₂O on heating from 20°С to 700°С in He gives WS₂, identified by the X-ray diffraction pattern. DFT calculations for [W₃S₄(tu)₈(H₂O)]⁴⁺ show that HOMO has a comparable contribution from metal- and ligand-centered atomic orbitals.