Carbonyl compounds, electron charge transfer states

Charge Transfer States in Cr(CO)f,. The electronic spectrum of metal carbonyl compounds is usually dominated by charge transfer (MLCT) transitions from the metal 2d orbitals into the CO it orbitals. In the case of Cr(CO)g, the 12 CO tt orbitals are found in the molecular orbitals 9fi , 2t2u, 2t g, and 2t2g. The region 3.5-7 eV in its spectrum is therefore built from a broad range of charge transfer transitions [200], of which, however, only two transitions are both spin and symmetry... 

By 1967 the kinetic model for nondissociative thermal electron attachment and revised values for the electron affinities of 16 aromatic hydrocarbons and 7 aromatic carbonyl compounds were reported [24-26]. The ECD Ea values were correlated to theoretical calculations, electronegativities, spectroscopic data, and reduction potentials. The majority of these remain the most precise electron affinities for such compounds. Some values are assigned to excited states based on the multistate model of the ECD postulated in the 1990s [27, 28]. The electron affinities of atoms, molecules, and radicals were reviewed in 1966 [24]. The relative Ea of nitrobenzene, CS2, and SO2 were measured by the thermal charge transfer techniques and the Ea of O2 by photodetachment [30-32]. 

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