Abstract

Time-resolved, fluorescence-detected infrared-ultraviolet double resonance (IR-UV DR) techniques have been used to investigate the spectroscopic and dynamical behaviour of acetylene (C₂H₂) molecules in two rovibrational manifolds: ν_CC + 3ν_ch at~11 600 cm^–1 [1] and 4ν_ch at ~12 700 cm^–1 [2]. The high symmetry and structural simplicity of the C₂H₂ molecule suggest that its behaviour at these 'chemically insignificant' levels of excitation should be regular and predictable. However, our IR-UV DR spectroscopic experiments in these regions reveal numerous puzzling anomalies.

© 2000 IEEE