Cu, Ag, and Au atom-molecular oxygen complexes: Matrix isolation ESR study

ESR spectra of complexes generated between Cu, Ag, and Au atoms and oxygen molecules cocondensed in rare gas matrices were examined. Formations of mono(dioxygen) complexes, Cu(O2), Ag(O2), and Au(O2), and bis(dioxygen) complexes, Cu(O2)2 and Ag(O2)2, were established, and their g tensors and the metal nuclear hyperfine coupling tensors were determined. Qualitative analyses of the spin Hamiltonian parameters indicate that the complexes are ionic pairs of the form M+(O2)- and M+(O2)2-, but Cu(O2) and Ag(O2) have a bent end-on structure, whereas Au(O2) has a symmetric side-on structure. © 1986 American Chemical Society.