Uv Photoelectron and Theoretical-studies of Organometal Carbonyl Clusters of Ruthenium and Osmium - Mu-hydrido-mu-3-allyl and Mu-hydrido-mu-3-allenyl Triangulo Cluster Compounds

.The electronic structures of p-hydr idep3- a l lyl and p-hydridep,-allenyl triangulo clusters of ruthenium and osmium a r e discussed on the basis of both H e I and H e I1 gas-phase UV-PE spectra and C N D O quantum-mechanical calculations. T h e theoretical results contribute t o t h e discussion of the P E d a t a and t o a deeper understanding of the bonding scheme in these very complex organometallic clusters. T h e description of the allyl cluster interactions in terms of one K and two u bonds seems to be adequate. On the other hand, t h e formal distinction into one u and two K bonds of the allenyl ligand cluster interaction is quite a n oversimplification of the a c tua l bonding scheme. T h e differences in thermodynamical stability between the allenyl and allyl derivatives a r e in agreement with the CNDO- comput ed total energies