Crystal structures of dichloridopalladium(II), -platinum(II) and -rhodium(III) complexes containing 8-(diphenylphosphanyl) quinoline

The crystal structures of dichloridopalladium(II), -platinum(II) and - rhodium(III) complexes containing 8-(diphenylphosphanyl) quinoline, (SP-4)-[PdCl₂(C₂₁H₁₆NP)], (1) [systematic name: dichlorido(8-diphenylphosphanyl-quinoline) palladium(II)], (SP-4)-[PtCl₂(C₂₁H₁₆NP)]·CH₂Cl₂, (2) [systematic name: dichlorido(8-diphenylphosphanylquinoline) platinum(II) dichlorometh-ane monosolvate], and (OC-6-32)-[RhCl2(C₂₁H₁₆NP)₂]PF₆·0.5CH₂Cl₂·-0.5CH₃OH, (3) [systematic name: cis-dichloridobis(8-diphenylphosphanyl-quinoline) rhodium(III) hexafluoridophosphate dichloromethane/methanol hemisolvate] are reported. In these complexes, the phosphanylquinoline acts as a bidentate ligand, forming a planar asymmetrical five-membered chelate ring. The palladium(II) and platinum(II) complex molecules in (1) and (2), respectively, show a typical square-planar coordination geometry and form a dimeric structure through an intermolecular π-π stacking interaction between the quinolyl rings. The centroid-centroid distances between the stacked six-membered rings in (1) and (2) are 3.633 (2) and 3.644 (2) Å, respectively. The cationic rhodium(III) complex in (3) has a cis(Cl),cis(P),cis(N) (OC-6-32) configuration of the ligands, in which two kinds of intramolecular π-π stacking interactions are observed: between the quinolyl and phenyl rings and between two phenyl rings, the centroid-centroid distances being 3.458 (2) and 3.717 (2) Å, respectively. The PF₆^- anion in (3) is rotationally disordered, the site occupancies of each F atom being 0.613 (14) and 0.387 (14). The CH₂Cl₂ and CH₃OH solvent molecules are also disordered and equal site occupancies of 0.5 are assumed.