Dioxygen bound to copper and nickel halides: matrix-isolation FTIR and DFT studies on ClCu(O2) and ClNi(O2) molecules

Reaction of laser-ablated CuCl molecules with dioxygen upon condensation in excess argon results in IR absorption at 1175.0 cm−1, which is assigned to the O–O stretching vibration of the ClCu(O2) molecule based on isotopic substituted experiments. DFT calculations predicted a 3B1 ground state ClCu(O2), in which the O2 unit possesses a η2 binding mode to the metal center with C2v symmetry. Similar results were obtained in laser-ablated NiCl and O2 reactions. The O–O stretching vibration of the 4A1 ground state ClNi(O2) molecule was observed at 1097.7 cm−1 in solid argon.