Reactions of laser-ablated Cu with NO: Infrared spectra and density functional calculations of CuNO+, CuNO, Cu(NO)(2), and Cu(NO)(2)(-) in solid neonand argon

Laser-ablated copper atoms react with NO molecules in excess neon and argon during condensation to form the CuNO and Cu(NO)(2) complexes as major prod ucts and Cu(NO)(2)(NO)* as a minor product. In addition, the CuNO+ cation a nd Cu(NO)(2)(-) anion are also formed. The product absorptions are identifi ed from isotopic shifts and splitting patterns in the matrix infrared spect ra and are supported by DFT calculations of isotopic frequencies. Sequentia l annealing increases CuNO and Cu(NO)(2), and then CuNO gives way to Cu(NO) (2) and Cu(NO)(2)(NO)*, a dinitrosyl with a third inequivalent NO subgroup. The isolated mononitrosyl and dinitrosyl species provide a scale to estima te local charge on CuNO and Cu(NO)(2) sites in Cu-exchanged zeolite catalys t systems.