ELECTRONIC-STRUCTURE OF METAL-CLUSTERS .5. PHOTOELECTRON-SPECTRA AND MOLECULAR-ORBITAL CALCULATIONS OF HYDROGEN-BRIDGED AND HALOGEN-BRIDGED TRIOSMIUM DECACARBONYLS

The gas-phase, ultraviolet photoelectron (PE) spectra and molecular orbital (MO) calculations are reported for (-H)-(-X)Os3(CO)10 and (-X)2Os3(CO)10 (X = CI, Br, I). We observe a loss of intensity in the ionization region of the Os-Os bonds compared to that of Os3(CO)12. The MO calculations suggest that the only direct Os-Os bonds in both of these bridging series are the two (CO)4Os-Os(CO)3 bonds. The (CO)3Os-Os(CO)3 interaction in the (-H)(-X) series is weakly bonding, while that in the (-X)2 series is weakly antibonding. Shifts in the positions of the ionizations due to the t2g-like orbitals are observed. The MO calculations suggest that the t2g-like Os(CO)3 orbitals, which are usually considered only M-CO bonding, interact strongly with the bridging H and halogen atoms to produce the observed shifts. 1983, American Chemical Society. All rights reserved.

ELECTRONIC-STRUCTURE OF METAL-CLUSTERS .5. PHOTOELECTRON-SPECTRA AND MOLECULAR-ORBITAL CALCULATIONS OF HYDROGEN-BRIDGED AND HALOGEN-BRIDGED TRIOSMIUM DECACARBONYLS Academic Article