Quantum interference effect on collisional energy transfer within singlet similar to triplet mixed states of Na-2 A (1)Sigma(+)(u)(v = 8) similar to b (3)Pi(0u)(v=14)

Tn a previous study [G.-H. Sha, B. Jiang, J.-B. He, C.-H. Zhang, J. Chem. P hys. 102 (1995) 2772], the first evidence for collisional quantum interfere nce (CQI) in intramolecular energy transfer within CO singlet similar to tr iplet mixed states was obtained. We present here another evidence for CQI e ffect on energy transfer within the singlet similar to triplet mixed states of Na-2(A (1)Sigma(u)(+), v = 8 similar to b(3)II(0u), v = 14) + Na(3s) by optical-optical double resonance fluorescence spectroscopy. The measured s tate-to-state cross-sections show the unique feature of abnormal Delta J-de pendence of cross-sections due to constructive or destructive interference. Molecular rotation speed and interaction potential have important effect o n the extent of interference. (C) 2000 Elsevier Science B.V. All rights res erved.