Time-Resolved Phosphrescence Spectra of Matrix-Isolated SO₂(³B₁)

Laser-induced emmision of SO₂ isolated in Ar, N₂ and CO matrices have been measured after its excitation to ¹B₁, ¹A₂ and ³B₁ states. The vibrational bands of the emission spectra of SO₂（³B₁ state） can be resolved in the Ar and N₂ matrices. The band width in CO matrix is so wide that the vibrational structure is barely seen. The dispersed fluorescence spectra of the ¹B₁ and ¹A₂ states are structureless. The fluorescence excitation spectra of the singlet and triplet are also measured. The similarity of the excitation spectra of the singlet and triplet states ranging from 276 to 284 um implies that the intersystem crossing could be observable. The time resolved emission of the singlet state and that of triplet state indicate that the time constant of the intersystem crossing is 2-3 μs.The matrix effect on the coupling of the singlet and triplet states is discussed.