Emission of CrO₂Cl₂ in rare gas solids: Excitation spectra and photoselection studies

Study of matrix emission and excitation spectra shows that the singlet state which dominates the gas phase visible spectrum of chromylchloride does not emit in low temperature solids. It undergoes a fast vibrational relaxation and radiationless transition into a lower lying electronic state. The two emission systems previously assigned to the lowest singlet and triplet respectively are shown to be emissions from the lower lying electronic state of CrO₂Cl₂ isolated in two distinct trapping sites. A partial reassignment of the upper state vibrational frequencies is proposed.