Heteroarylphosphorus ligands in platinum(II) complexes. The structure of trans-[Pt(P{2-(N-methylpyrrolyl)}iPr2)2Cl2]

Displacement of cod from [Pt(cod)Cl2] by 2 equiv. of heteroarylphosphorus ligand, PR2R′, in dichloromethane at ambient temperature afforded — but for one exception trans-[Pt(P{2-(N-methylpyrrolyl)}iPr2)2Cl2] (1) — the expected cis complexes, cis-[Pt(P{2-(N-methylpyrrolyl)}Ph2)2Cl2] (2), cis-[Pt(P{2-(5-methylthienyl)}R2)2Cl2] (R=Ph 3, iPr 4) and cis-[Pt(P{2-(5-bromopyridinyl)}iPr2)2Cl2] (5). The complexes were fully characterised and structural assignments were based on 1J(195Pt31P) coupling constants from the NMR data. The structure of 1 was determined by X-ray crystallography, which revealed that the two pyrrolyl substituents on the phosphine ligands were oriented on opposite sides of the PPtP axis.