Crystal Spectra of Hexaurea Complexes. II. Absorption and Emission in Crystals Containing the Hexaurea Chromium (III) Ion

Absorption and emission bands have been observed in crystals containing the hexaurea chromium(III) ion. The moderately sharp features in the region 14 160–14 250 cm⁻¹ have been examined in some detail in the temperature range 1.5°–300°K. A broad emission band has been seen at 12 300 cm⁻¹ and is considered to be the ${}^4{T}_{\text{2g}}{\mathrm{\hspace{0.17em}\to \hspace{0.17em}}}^4{A}_{\text{2g}}$ transition. Detailed radiative lifetime and quantum efficiency measurements lead to a proposal that includes the possible identification of the (0,0) ${}^4{T}_{\text{2g}}({\mathrm{O}}_h$ transition.