Synthesis, EPR spectrum and X-ray structure of tetra-n-butylammonium bis(benzene-1,2-dithiolato(2−)-κ2S,S′)platinate(III)

The new salt, tetra-n-butylammonium bis(benzene-1,2-dithiolato(2−)-κ2S,S′)platinate(III), [NBu4][Pt(C6H4S2)2] (1), has been synthesized in ethanol/water, and fully characterized by single crystal X-ray structure determination. The central platinum in the complex ion [Pt(bdt)2]− is tetracoordinated by the S atoms of the bdt2− ligands (bdt2− is benzene-1,2-dithiolate) in a square-planar geometry. The well-resolved frozen solution EPR spectrum exhibits rhombic symmetry. The room temperature effective magnetic moment (μeff = 1.80 Bohr magneton) is in line with this spectrum and strongly supports the Pt(III) oxidation state in 1. This observation is in excellent agreement with previous results reported on closely related Ni(III), Pd(III) and Pt(III) species.

The reaction of tetra-n-butylammonium chloride (NBu4Cl), dipotassium tetrachloroplatinate(II) (K2[PtCl4]) and benzene-1,2-dithiol (H2bdt) in ethanol/water readily affords the 1:1 salt of general formula [NBu4][Pt(bdt)2]. Single crystal X-ray structure of this salt shows that the central platinum is in a square-planar coordination geometry of four S atoms, and the frozen solution EPR spectrum and the room temperature magnetic moment of μeff = 1.80 B.M. are in accord with the assignment of the Pt(III) oxidation state.Figure optionsDownload as PowerPoint slide