Matrix isolation infrared spectroscopic and theoretical study of noble gas coordinated dipalladium-dioxygen complexes

The reaction products of palladium atoms with molecular oxygen in solid argon have been investigated using matrix isolation infrared absorption spectroscopy and quantum chemical calculations. In addition to the previously reported mononuclear palladium-dioxygen complexes: Pd(η2-O2) and Pd(η2-O2)2, dinuclear palladium-dioxygen complexes: Pd2(η2-O2) and Pd2(η2-O2)2 were formed under visible light irradiation and were identified on the basis of isotopic substitution and theoretical calculations. In addition, experiments doped with xenon in argon coupled with theoretical calculations suggest that the Pd(η2-O2), Pd2(η2-O2) and Pd2(η2-O2)2 complexes are coordinated by two argon or xenon atoms in solid argon matrix, and therefore, should be regarded as the Pd(η2-O2)(Ng)2, Pd2(η2-O2)(Ng)2 and Pd2(η2-O2)2(Ng)2 (NgAr or Xe) complexes isolated in solid argon.