Configurational selectivity in benzyldimethylarsine complexes of palladium(II) and platinum(II): synthesis, spectroscopy and structures

Benzyldimethylarsine complexes of palladium(II) and platinum(II) with the formulae [MX2(BzAsMe(2))(2)] (X = Cl, Br, I), [M2Cl2(mu-Cl)(2)(BzAsMe(2))(2)], [Pd2Cl2(mu-OAc)(2)(BzAsMe(2))(2)], [Pd2Me2(mu-Cl)(2)(BzAsMe(2))(2)] and [Pd2X2(mu-N <^> N)(2)(BzAsMe(2))(2)] (M = Pd or Pt; N <^> N = pyrazolate (pz) or 3,5-dimethylpyrazolate (dmpz)) have been prepared. All complexes have been characterised by elemental analysis, IR, UV-Vis absorption and NMR (H-1, C-13, Pt-195) spectroscopy. The molecular structures of the complexes [MX2(BzAsMe(2))(2)] (M = Pt or Pd; X = Cl, Br or I) have been established by NMR spectroscopy and single crystal X-ray diffraction analysis and reveal a clear dichotomy in solution and in the solid between the compounds with X = Cl in a cis configuration and the trans configured bromide and iodide complexes. (C) 2002 Elsevier Science B.V. All rights reserved.