TRENDS IN DELTA-]DELTA-STAR ENERGIES AND INTENSITIES IN BIS(ARYLIMINO)ISOINDOLINE COMPLEXES OF DIMOLYBDENUM

It has been found that the delta --> delta* band in the electronic absorption spectra of a series of bis(arylimino)isoindoline dimolybdenum complexes, Mo2(BAII)(OAc)3, follows three trends. First, as the energy of the band decreases across the series its intensity increases. Second, as electron-releasing groups are added to the aryl portion of the ligand the energy of the band increases, while addition of electron-releasing groups decreases its energy. Third, as the parent aryl group becomes a better pi-acceptor the band's energy decreases. These three trends are taken to indicate that the energy of the delta --> delta* band in this series of compounds is determined by mixing of a ligand-to-metal charge-transfer transition with the original delta --> delta* transition.