High-pressure vibrational study of the catalyst candidate cis-dimercaptobis(triphenylphosphine)platinum(II), cis-[(Ph3P)2Pt(SH)2]

Infrared and FT-Raman spectra of cis-dimercaptobis(triphenylphosphine)platinum(II), cis -[(PPh3)(2)Pt(SH)(2)], have been measured at high external pressures up to 55 kbar with the aid of a diamond-anvil cell (DAC). The wavenumber (v) versus pressure (P) plots from the Raman data indicate the occurrence of a pressure-induced phase transition at around 15 kbar. The metal-ligand stretching mode, v(Pt-S), and the C-H stretching mode of the phenyl rings, v(C-H), are highly sensitive to the application of pressure (dv/dP similar to 1.0 cm(-1)kbar(-1)). The IR results are generally consistent with the Raman data. The pressure-induced phase transition is most probably attributable to the reorientation of the phenyl rings in the complex; similar results have been obtained for other phenyl derivatives. (C) 2002 Elsevier Science B.V. All rights reserved.