The crystal and molecular structure of [Pd(TPAS)Cl]ClO3,C6H6[TPAS =o-phenylenebis-(o-dimethylarsinophenylmethylarsine)]: the stereochemistry of a pentaco-ordinate palladium complex ion

Abstract

A single-crystal X-ray structure analysis of [Pd(TPAS)Cl]ClO₄,C₆H₆[TPAS =o-phenylenebis-(o-dimethylarsinophenylmethylarsine)] is reported. The pentaco-ordinate complex [Pd(TPAS)Cl]⁺ crystallises with perchlorate ions in an ionic lattice in which benzene molecules are included as a clathrate. The complex ion has a square pyramidal co-ordination with a chlorine atom in the basal plane in which the palladium atom is coplanar with the four attached atoms. The apical palladium–arsenic bond is almost 0·5 Å longer than those in the basal plane which also differ significantly from each other. No hydrogen atom of the ligand can be closer than 3·5 Å to the palladium atom and so the possibility of completion of octahedral co-ordination by hydrogen is excluded. The preferred geometry of the complex ion is fully discussed.