Palladium(II), platinum(II), and rhodium(III) complexes of o-phenylene-bis(diphenylarsine) and (o-diphenylarsinophenyl)diphenylphosphine

Abstract

Thirty five complexes of o-phenylenebis(diphenylarsine)(pdpa) and (o-diphenylarsinophenyl)diphenylphosphine (padpp) including types [M(L)X₂], [ML₂][ClO₄]₂, [M(L)₂X₂](M = Pd or Pt; L = pdpa or padpp; X = Cl, Br, I, or CNS), and [Pd(pdpa)₂X]ClO₄ have been prepared. The planar thiocyanates are formulated [Pd(pdpa)(NCS)(SCN)] and [Pt(padpp)(NCS)(SCN)]. In dichloromethane the [Pt(pdpa)(SCN)₂] complex partly isomerises to [Pt(pdpa)(NCS)(SCN)]. The five-co-ordinate [PdL₂(NCS)]CNS (L = pdpa or padpp) species also isomerise in solution. The diperchlorates are planar, whilst in solution the [M(L)₂X₂] complexes are predominantly five-co-ordinate. On heating, the [M(L)₂X₂](X = Cl, Br, or I) complexes dissociate in the solid state into [M(L)X₂] and free L. The tendency to five-co-ordination is Pd > Pt and pdpa > padpp. Rhodium(III) halides form adducts [Rh(pdpa)₂X₂]X (X = Cl, Br, or I), [Rh(padpp)₂X₂]X (X = Cl or Br), and [{Rh(padpp)I₃}₂].