ELECTRONIC-STRUCTURE AND PHOTOBEHAVIOR OF HEXAAMMINECHROMIUM(III) ION

The electronic structures of the hexaamminechromium (III) ion [Cr(NH3)6]3+ in its quartet ground state and in its lower excited quartet and doublet states have been investigated through theoretical models based upon a combination of MS-LSD, LCGTO-LSD and ligand-field procedures. The calculations have been carried out in the contexts of O(h) and D4h microsymmetries, the latter being applicable to consideration of the first quartet excited state, which is known from experiment to undergo distortion to a tetragonal geometry. The calculated results in conjunction with spectroscopic findings have provided new insight into examining the photobehavior of this complex ion with specific reference to internal conversion between lower excited quartet states, promoted by spin-orbit interaction, and to the potential involvement of a back intersystem crossing from the lowest excited doublet state [2E(g)(O(h))] to the lowest excited quartet [4E(g)(D4h)].