A MOLECULAR ORBITAL TREATMENT OF THE SPECTRUM OF TiF6(3-),

Electronic energy levels for complex TiF6-3 ions have been calculated using a molecular orbital scheme, assuming ideal octahedral co ordination, taking into account pi-bonding, but not considering ligand-ligand interactions. The inclusion of pi-bonding is shown to be most important when the calculated energy levels are compared with the observed spectra of compounds containing the complex. The observed spectra of NH43TiF6, Na2KTiF6, and NaK2TiF6 show two bands at 15-16,000 and at 18,900 reciprocal cm. The value of 17,500 reciprocal cm for 10 Dq obtained from the calculated energy levels compares very favorably with the observed spectra, the split ting being attributed primarily to Jahn-Teller distortion of the excited state. Author