Hydrogen-atom photofragment spectroscopy. Photodissociation dynamics of H2O in the B–X absorption band
The photofragmentation dynamics of H2O molecules following vacuum ultraviolet laser excitation at wavelengths within the B1A1–X1A1 absorption band have been investigated using a novel from of photofragment translational spectroscopy. Analysis of the nascent H atom time-of-flight spectra confirms the importance of the dissociation channel leading to ground-state H + OH products. In addition, it reveals that the OH(X) fragments are formed predominantly in their zero-point vibrational level with a highly excited, inverted rotational-state population distribution. A consideration of the topology of the various potential-energy surfaces sampled by the H2O molecules during this electronically non-adiabatic dissociation process suggests a likely explanation for this observed pattern of energy disposal.
- This article is part of the themed collection: Celebrating the 150th anniversary of the German Chemical Society