THE CHEMISTRY OF PYRIDINE THIOLS AND RELATED LIGANDS - 8 - SYNTHESIS,NMR-SPECTROSCOPY AND CRYSTAL-STRUCTURE OF FIRST -THIOLATO-S)-BIS(TRIPHENYL-PHOSPHINE)PLATINUM(II)]

Reaction of bis(pyridine-2-thiolato-N, S)platinum(II) (1) in acetonitr ile (obtained from PtCl2 and Na+C5H4NS-) with two equivalents of PPh3 forms monomeric Pt(C5H4NS)(2)(PPh3)(2) (2) whose X-ray structure has b een determined. It crystallises from a acetonitrile-chloroform mixture and exists as a centrosymmetric square planar monomer. Pyridine-2-thi olate binds to Pt via S-atoms in a trans-configuration and the other t wo positions are occupied by P atoms of PPh3. The interatomic importan t parameters are: Pt-S = 2.343(2), Pt-P=2.3147(13), C-S = 1.739(6) Ang strom, bond angles P-Pt-P and S-Pt-S* each-=180.0 degrees, P-Pt-S, P* -Pt-S = 85.24 degrees (acute) and P-Pt-S, P*-Pt-S = 94.76 degrees (ob tuse). It represents the first example of a structurally characterised S-bonded pyridine-2-thiolato Pt(II) complex. The NMR data (H-1, C-13, P-31) suggest dissociation of 2 in CDCl3 as follows: Pt(C5H4NS)(2)(PP h3)(2) (2)-->Pt(C5H4NS)(2)CPPh3) (2a)+ PPh3. Both N,S- and S-bonded C5 H4NS- moieties are confirmed from H-1 and C-13 NMR. (C) 1998 Elsevier Science Ltd. All rights reserved.