The gerade states of acetylene at 9‐10 eV have been studied by monitoring the C2 emission. Larger Δv2 excitations are seen than previously reported by Ashfold et al. The observed two‐photon resonant levels show extensive predissociation. Experimental evidence from the two‐color photofragment excitation measurement is given to support the conclusion that the excited‐state ethynyl radical and atomic hydrogen are the corresponding predissociation products. Most C2 emissions seen in this work are due to the subsequent photodissociation of the intermediate C2H to C2 (d3Πg).
- Photodissociation: Acetylene
- Photofragment Excitation Spectroscopy
- Two‐photon Spectroscopy