Metallo-dithiolenes electronic-spectroscopic structural studies

The most detailed spectroscopic and electronic structure studies of metallo-mono(dithiolenes) have focused on the nature of ligand-to-ligand charge transfer (LLCT) excitations in [M(diimine)(dithiolene)] complexes (112, 250-257, 262, 264, 295-301) and in monooxo molybdenum dithiolenes (19, 20, 22, 23) as models for pyranopterin molybdenum enzymes such as sulfite oxidase (SO). Since metallo-mono(dithiolenes) generally possess little or no symmetry, detailed spectrosopic and electronic structure studies of this class of metallo-dithiolenes have only recently begun to appear. The analysis of the spectroscopic data has been aided by the fact that the dithiolene-to-metal charge... 

The electronic structure and spectroscopy of metallo-bis(dithiolenes) are considerably more complicated than that of the metallo-mono(dithiolenes) discussed in Section II.C because there are now two dithiolene donors, which result in twice as many sulfur-based MOs that contribute to the overall metal-ligand bonding scheme. The result is an increase in the density of states in the valence region, with a concomitant increase in the number of Sdithioiene — M CT excitations. Nevertheless, numerous spectroscopic studies and bonding calculations have been undertaken in order to explain the unique electronic properties of these molecules. The fact that two dithiolene ligands are now coordinated to... 

The best understood oxo-metallo-bis(dithiolenes) possess the general formula [MO(dithiolene)2]". Although dioxo [M02(dithiolene)2]2 (33, 34, 70, 314, 391-393) and desoxo [MX(dithiolene)2] (X = OR, SR, or SeR) (58, 327, 394) complexes have also been studied, considerably less is known of their spectroscopic properties and electronic structures. Therefore, they will not be... 

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