The electron energyhyphen;loss spectra of Cr(CO)6, Mo(CO)6, and W(CO)6were measured at impact energies of 25, 50, and 100 eV and at scattering angles from 0deg; to 90deg;. The differential cross sections (DCSrsquo;s) were obtained for several features in the 3ndash;7 eV energyhyphen;loss region. The symmetryhyphen;forbidden nature of the1A1grarr;1A1g,2t2g(pgr;)rarr;3t2g(pgr;ast;) transition in these compounds was confirmed. Several low energy excitations were assigned to ligand field transitions on the basis of the energy and angular behavior of their associated DCSrsquo;s. No transitions which could clearly be assigned to singletrarr;triplet excitations involving metal orbitals were located in these molecules. In addition, a number of states lying above the first ionization potential were observed for the first time. Several of these excitations seem to correspond quite well to some of the transitions observed in free CO.
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