Laser induced fluorescence spectrum of matrix isolated CS⁺ ₂

The laser induced fluorescence spectrum of the CS₂ cation has been obtained in solid Ne and Ar matrices. The transitions observed originate in the X ²Π state and terminate in the A ²Π state. In the Ne matrix, sharp lines with well resolved vibrational structure are observed. There is only a very small difference between gas-phase and Ne matrix values for the electronic origin and vibrational frequencies, although the latter analysis can be extended somewhat in the matrix. In the Ar matrix only a poorly resolved and strongly shifted CS₂⁺ spectrum is observed. A qualitative explanation for this different behavior is advanced.