Vibrationally hot emission and electronic relaxation of CO in Ne matrix

Vibrational progressions due to radiative decay of A 1Π (v′=0, 2, 3 5, 6, 8), e 3∑ (v′=0, 3, 5, 12), a′ 3∑ (v′=5, 14), d 3Δ (v′=3, 5), a 3Π (v′=0, 1, 2) to the ground state and of e 3∑ (v′=3, 5, 7, 9, 11, 12) and d 3Δ (v′=3, 7, 11) to the a 3Π state have been observed for selective excitation of A 1Π (v′=0, . . . ,8). The intersystem crossing rate constants, the bottle necks, pathways and rate constants for internal conversion in the triplet levels and the triplet–singlet radiative rate constants are explained by an intramolecular mixing of electronic states and electron–phonon coupling with the matrix.