HYDRIDE TO CARBENE MIGRATION AT PLATINUM(II) - SYNTHESIS AND X-RAY STRUCTURE OF CIS-((PPH3)2PT[C(H)SCH2CH2S])BF4

The hydrido-dithiocarbene complex trans-[(PPh3)2PtH(CSCH2CH2S)]BF4 (1) undergoes thermal rearrangement in CH3CN by hydride to carbene migration to form the complex cis-{(PPh3)2Pt[C(H)SCH2CH2S]}-BF4 (2), whose molecular structure has been determined by a single-crystal X-ray analysis (monoclinic, P2(1)/n; a = 16.255 (3) angstrom, b = 20.423 (3) angstrom, c = 11.406 (2) angstrom, beta = 94.42 (4)-degrees, V = 3773(1) angstrom3, Z = 4, R = 0.047, R(w) = 0.054 for 4447 measured reflections with I > 3sigma(I)). The rearrangement of 1 to 2 proceeds also with Cl- ions. In this latter reaction the neutral complex trans-[(PPh3)2PtCl[C(H)SCH2CH2S] (3) could be isolated in the solid state, but it isomerizes in solution by intramolecular displacement of Cl- by one sulfur atom of the dithiolane ring to give cis-{(PPh3)2Pt[C(H)SCH2CH2S]}Cl (2'), which is structurally similar to 2.