Further studies on the chemistry of tetramethylthiourea-platinum complexes: Evolution of cis-[PtCl{S=C(NMe2)(2)}(PPh3)(2)](+) to the dinuclear monothiocarbamato-sulfido complex [Pt-2(mu-S){mu-SC(O)NMe2}(PPh3)(4)](+)
Document Type
Article
Publication Date
1-1-2015
Abstract
Reaction of cis-[PtCl2(PPh3)(2)] with tetramethylthiourea (tmtu) in methanol under various conditions has been re-investigated. In the absence of base, the simple ligand substitution product [PtCl(tmtu)(PPh3)(2)]PF6 can be isolated by addition of excess NH4PF6. The complex was characterised by positive-ion ESI mass spectrometry, NMR spectroscopy and an X-ray structure determination. In refluxing methanol with excess Me3N, cis-[PtCl2(PPh3)(2)] reacts with tmtu to give a yellow solution containing the dinuclear monothiocarbamato complex [Pt-2(mu-S){mu-SC(O)NMe2}(PPh3)(4)](+); the complex was isolated as BPh4- or PF6- salts. The X-ray structure of [Pt-2(mu-S){mu-SC(O)NMe2}(PPh3)(4)]BPh4 center dot CHCl3 is described. ESI mass spectrometry has been used to identify various reaction intermediates and by-products in the synthesis of [Pt-2(mu-S){mu-SC(O)NMe2}(PPh3)(4)](+). [Pt-2(mu-S){mu-SC(O)NMe2}(PPh3)(4)](+) acts as a metalloligand, e. g. towards PhHg+, but a pure product was unable to be isolated. DFT calculations suggest the presence of a Hg center dot center dot center dot O=C interaction. (C) 2014 Elsevier B.V. All rights reserved.
Keywords
Platinum complex, Thiourea ligand, Monothiocarbamato ligand, Electrospray mass spectrometry, X-ray crystal structure, DFT calculations
Publication Title
Inorganica Chimica Acta
Volume
425
Publisher
Elsevier
Publisher Location
PO BOX 564, 1001 LAUSANNE, SWITZERLAND