Detection of OH(X,v '',J '') via the B (2)Sigma(+)-X (2)Pi transition and properties of the B (2)Sigma(+) state

A number of OH B(2)Sigma (+)-X(2)Pi vibration-rotation spectra have been ob tained using laser-induced fluorescence (LIF). Vibrationally excited OH(X,v " = 6-9) was formed through the reaction of H with O-3. and the v ", J " - dependent populations were characterized through synthetic spectral fitting of the B-X 0-v " spectral data. The populations have been partially relaxe d by collisions in the source region. The OH(B-X) 0-v " relative band inten sities have been determined and agree with previous theoretical values. Sev eral OH(B,v " = 0) J ' -dependent collision-free lifetimes have been measur ed; the lifetimes decrease rapidly with J '. The B (2)Sigma (+) state is we akly predissociated through a combination of spin-orbit and L-uncoupling (" gyroscopic") perturbation interactions with the nearby 2 (2)Pi state. Altho ugh the OH B-X LIF technique cannot be used to monitor high rotational leve ls, it is well-suited for detecting the populations of high vibrational lev els of the X (2)Pi state because of favorable Franck-Condon overlap. it als o allows for operation at much lower reactant densities than is possible us ing the less sensitive OH chemiluminescence detection technique, mitigating the risk of unforeseen chemistry from metastable-metaslable reactions. The se results should add confidence in deriving accurate OH X (2)Pi v " ,J " - dependent populations from B-X spectra.