Persistence of oxidation state III of gold in thione coordination

• Published in: Solid state sciences 2017-05, Vol.67, p.37-45
• Main Authors: Jääskeläinen, Sirpa, Koskinen, Laura, Kultamaa, Matti, Haukka, Matti, Hirva, Pipsa
• Format: Article
• Language: English
• Subjects: DFT; Gold(III); QTAIM; Tetramethylthiourea; Thione
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2017.03.008

Ligands N,N'-tetramethylthiourea and 2-mercapto-1-methyl-imidazole form stable Au(III) complexes [AuCl3(N,N'-tetramethylthiourea)] (1) and [AuCl3(2-mercapto-1-methyl-imidazole)] (2) instead of reducing the Au(III) metal center into Au(I), which would be typical for the attachment of sulfur donors. Compounds 1 and 2 were characterized by spectroscopic methods and by X-ray crystallography. The spectroscopic details were explained by simulation of the UV-Vis spectra via the TD-DFT method. Additionally, computational DFT studies were performed in order to find the reason for the unusual oxidation state in the crystalline materials. The preference for Au(III) can be explained via various weak intra- and intermolecular interactions present in the solid state structures. The nature of the interactions was further investigated by topological charge density analysis via the QTAIM method. [Display omitted] •Thione derivatives of gold were synthesized and characterized.•Oxidation state III was atypically maintained.•Computational TD-DFT studies were used to explain spectroscopic data.•DFT and QTAIM methods were employed to clarify the oxidation state of the metal and the weak interactions in solid state.