Experimental and ab initio study of the molybdenum K and L edge excitation in Mo(CO)6 and MoF6 Original Research Article

The L inner-shell absorption spectra of molybdenum in gas phase Mo(CO)6 and MoF6 have been obtained at room temperature with a direct ion-yield technique at the LURE Super ACO storage ring in Orsay. Transitions from the 2p32 and 2p12 initial states, respectively, have pronounced “white line” features assigned to the allowed 2p → 4d transitions and as expected the Mo 2p spectra are found to be very sensitive to the nature of the ligands and their bonding. Most of the intensity in the Mo 2s excitation spectra goes above the ionization threshold. Ab initio calculations employing the 1h-1p CI scheme, performed for the K and L excitation of molubdenum, permit to assign spectral features below the ionization thresholds and to deduce from the oscillator strength the metal character of the vacant orbital.