M. Guerra, Derek Jones, G. Distefano
1988
Citations
0
Influential Citations
12
Citations
Journal
Journal of the American Chemical Society
Abstract
The electron affinities in the 0-5 eV energy range have been determined for chromium hexacarbonyl and iron pentacarbonyl by means of multiple scattering X..cap alpha.. calculations. The total electron scattering cross sections have been estimated with the continuum MS-X..cap alpha.. method. The computational results are compared with the electron transmission spectra and used for the assignment of the experimental features. The ET spectrum of Fe(CO)/sub 5/ is presented and assigned for the first time and that of Cr(CO)/sub 6/ is reassigned. For both complexes, all the anion states associated with electron capture into the orbitals deriving from the ligand 2..pi..* MOs and into the metal empty d orbitals are assigned to resonances occurring in the 0.4-2.6 eV energy region of the ET spectra. A charge density analysis reveals that a net electronic charge transfer occurs from the ligands to the metal, owing to the acceptor capability of the metal 4s and 4p orbitals. This is consistent with the experimentally observed average stabilization of the anion states localized at the CO ligands with respect to the II anion state of free CO.