Synthesis of cationic palladium(II) and platinum(II) complexes with a monodentate trialkylphosphoniumdithiocarboxylate ligand: molecular structure of trans-[Pd(C6F5)(PEt3)2(S2C–PEt3)]ClO4·CHCl3

Abstract

Reaction of trans-[M(OClO₃)(C₆F₅)(PR₃)₂] with the zwitterion S₂C–PR′₃ affords the complexes trans-[M(C₆F₅)(PR₃)₂(S₂C–PR′₃)]ClO₄(M = Pd; R₃= R′₃= Et₃, Bu₃, or Et₂Ph; R = Bu, R′= cyclo-C₆H₁₁; R = Ph, R′= Et or cyclo-C₆H₁₁ M = Pt, R = R′= Et or Bu). trans-[Pd(C₆F₅)(PEt₃)₂(S₂C–PEt₃)]ClO₄ is also given by reaction of [Pd(C₆F₅)(PEt₃)₃]ClO₄ with CS₂. Reaction of [M(OClO₃)(C₆F₅)(bipy)](bipy = 2,2′-bipyridyl) with S₂C–PR′₃ affords [M(C₆F₅)(bipy)(S₂C–PR′₃)]ClO₄(M = Pd or Pt; R′= Et, Bu, or cyclo-C₆A₁₁). A crystallographic study of trans-[Pd(C₆F₅)(PEt₃)₂(S₂C–PEt₃)]ClO₄(as its 1:1 chloroform solvate) shows that the cation contains a unidentate triethylphosphoniumdithiocarboxylate ligand, and ³¹P n.m.r. spectra of all products with two terminal phosphine ligands are consistent with trans stereochemistries. Crystals of trans-[Pd(C₆F₅)(PEt₃)₂(S₂C–PEt₃)]ClO₄˙CHCl₃ are monoclinic, space group P2₁/a, with a= 14.596 5(18), b= 15.356(3), c= 19.324 2(16)Å, β= 109.257(8)°, and Z= 4. Using 4 093 amplitudes the structure has been refined to R= 0.1049. The non-bonding Pd ⋯ S distance is 3.644(4)Å.