Photoionization spectroscopy of metal dimers and weakly bound metal atom complexes

Electronic spectra are observed for three new heteronuclear metal dimers (LiAl, CuLi and AgLi) and four weakly bound metal atom complexes (AgAr, AgKr, AgXe and CuKr). LiAl is produced by laser vaporization of an alloy metal sample in a pulsed nozzle cluster source. The metal dimers CuLi and AgLi are produced in a supersonic molecular beam by laser vaporization of either a copper or silver rod coated with thin film of vacuum deposited lithium metal. Resonant two-photon ionization (R2PI) is employed to collect the spectra.; Two electronic band systems are observed and characterized for the heteronuclear metal dimer, LiAl. The analysis provides the ground and excited state frequencies and dissociation energies. The ground state frequency (318.3 cm{dollar}sp{lcub}-1{rcub}){dollar} and dissociation energy (0.75 eV) both agree well with the predictions of ab initio theory. Ionic contributions to the ground state bonding of LiAl is negligible. However, ionic bonding is significant in the ground states of CuLi and AgLi. Investigations of the ground state energetics of CuLi and AgLi reveal the dissociation energies are greater, and the bond lengths are shorter than expected if these dimers exhibited pure covalent bonding. These trends indicate that ionic character plays a leading role in the ground state bonding.; The Ag-RG (RG = Ar, Kr and Xe) and CuKr complexes are formed easily by laser vaporization of a Ag or Cu rod in an expansion containing argon, krypton or xenon. The laser technique R2PI is used to probe the electronic spectra of these van der Waals complexes. The observed spectra correspond to the {dollar}sp2Pisb{lcub}1/2,3/2{rcub}gets sp2Sigmasb{lcub}1/2{rcub}{dollar} band system, which correlates to the Ag (or Cu) {dollar}rmsp2Pgets sp2{dollar}S asymptote. Interesting trends in vibrational frequencies and dissociation energies as a function of rare gas are discussed. In addition, the vibrational state dependence of the spin-orbit splitting between the {dollar}sp2Pi{dollar} states of Ag-RG is examined. A comparison of the ground and excited state dissociation energies of CuKr and AgKr reveals interesting sd hybridization in the ground state of CuKr, and pd hybridization in the AgKr excited state.