Optical transitions of a D4h complex with one electron in a1g (≈3z2-r2):: study of RhCl4-6

Optical transitions of the elongated RhCl64- complex in NaCl have been calculated in the DFT framework together with the oscillator strength of allowed gamma --> a(1g) charge transfer (CT) transitions. The experimental peak at 3.66 eV is shown to arise from a jump from a(2u)(ax) mainly built from axial ligands and thus the onset of CT transitions for RhCl64- appears at a lower energy than that for RhCl63-. This fact is partially related to the Jahn-Teller effect in RhCl64- The present calculations on RhCl64- also explain the crystal field spectrum and predict the existence of additional CT transitions in the 4-5 eV range. (C) 2003 Elsevier Science B.V. All rights reserved.