Luminescence and 4A2→2E, 2T1 absorption spectrum of Cr(urea)6I3 and Al(urea)6I3:Cr(urea) 3+6

Abstract

A re-examination of the luminescence and absorption spectrum of Cr(urea)₆I₃ and Al(urea)₆I₃: Cr(urea)³⁺₆ shows that the diluted material contains local concentrations of Cr(urea)³⁺₆ ions within which energy transfer processes from majority sites to minority sites occur. These processes also occur in pure Cr(urea)₆I₃. The absorption spectrum may be completely analysed as ⁴A₂→²E, ²T₁ electronic origins together with vibronic origins involving vibrational intervals similar to those observed in the luminescence, infrared and Raman spectra.