Synthesis, structures, and DFT analysis of gold complexes containing a thiosemicarbazone ligand

• Published in: New journal of chemistry Vol. 45; no. 39; pp. 18433 - 18442
• Main Authors: Mageed, Ahmed Hassoon, Al-Ameed, Karrar
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 11.10.2021
• Subjects: Acetonitrile; Coordination compounds; Crystallography; Gold compounds; Ligands; Mass spectrometry; NMR spectroscopy; Solvation; Synthesis
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d1nj03647e

In this study, we report the synthesis of a series of new gold compounds in different solvation media. First, gold( i ) thiosemicarbazone (TSC) [Au-(TSC) 2 ]Cl was synthesized by reacting [Au(SMe 2 )]Cl with a thiosemicarbazone ligand in acetonitrile. Then, we successfully managed to replace one of the monodentate thiosemicarbazone ligands with Cl to prepare the TSC-AuCl complex by the reaction of KAuCl 4 with thiosemicarbazone in acetonitrile. In a different strategy, the reaction of KAuCl 4 with thiosemicarbazone in methanol formed a [TSC-AuCl]AuCl 2 complex of tridentate (NNS) thiosemicarbazone. All complexes were fully characterized by X-ray diffraction, 1 H and 13 C NMR spectroscopy, and mass spectrometry. The 1 H and 13 C NMR spectra of the [Au-(TSC) 2 ]Cl in DMSO- d 6 solution showed two sets of signals, suggesting the presence of two complexes formed from ( E )- and ( Z )-TSC, respectively. X-ray studies showed only one complex from ( Z )-TSC, and the ( Z )-TSC ligands provide an exactly linear coordination arrangement around the Au( i ) centres. X-ray crystallography showed [TSC-AuCl] + cations in the AuCl 2 salts to have a square pyramidal geometry. Complexes of TSC-AuCl and [TSC-AuCl]AuCl 2 had limited stability, decomposing rapidly in solution, while the [Au-(TSC) 2 ]Cl complex was stable in solution. A mixture of E , Z -thiosemicarbazone (TSC) allows the formation of two Au( i ) complexes; the reaction of TSC with KAuCl 4 yields two complexes in different solvents.