Absorption spectrum of Yb3+(4f13) in [(C6H5)3PH]3YbCl6

Optical absorption spectra taken at 300 and 77 K are reported for six-fold octahedrally coordinated Yb3+(4f13) in [(C6H5)3PH]3YbCl6. In addition to vibronic spectra the authors observe electronic transitions which suggest that inversion symmetry is lifted by a small distortion similar to that reported for the Nd3+(4f3) spectrum of the corresponding salt. The vibronic as well as the electronic transitions have been analyzed on the basis of six-fold octahedral symmetry. The analysis appears reasonable and consistent in comparison with other rare-earth ions that have been studied in similar cubic and octahedral environments. (Auth.)