Electron velocity map imaging and theoretical study on CuXH (X=O and S) anions.

Vibrationally resolved photoelectron spectra of CuOH- and CuSH- have been determined via velocity map imaging method to investigate the transitions of X1 A'←X2 A' at 532nm. Adiabatic detachment energies of CuOH- and CuSH- are assigned to 0.995(12) and 1.098(12) eV, respectively. Combined theoretical calculations with Franck-Condon simulations, it allows extracting the vibrational frequencies in neutral, which yields 629(32) cm-1 with CuO stretching mode and 387(24) cm-1 with CuS stretching mode for CuXH (X=O and S). Parallel transition properties of photoelectron angular distributions (PADs) for both species are correlated to the photodetachment of SOMO orbitals, which mainly involved in the Cu atom s orbital and partial s orbital in other atoms. Based on chemical bonding analyses (Wiberg, NAO, Mayer, NRT, and ELF), it is suggested that a trend is observed with a subtle variation of covalent component from weak covalent behavior between CuO in CuOH-1/0 to stronger covalent bonding between CuS in CuSH-1/0 (especially for non-ignorable covalent component in CuSH species) though ionic bonding dominates both in CuO and CuS bonds for the two systems.