QUENCHING OF B1-SIGMA-G+ OXYGEN IN SOLUTION

b1SIGMA(g)+O2 has been directly monitored by its fluorescence at 1926 nm (b1SIGMA(g)+O2 --> a1DELTA(g)O2). Stern-Volmer quenching studies have been performed for seven organic molecules in a host solvent of CCl4. The quenching of b1SIGMA(g)+O2 follows some of the same trends observed for the quenching of a1DELTA(g)O2, as expected for a pr defined, in part, by electronic-to-vibrational energy transfer. Deuterium isotope effects for quenching, however, differ substantially for b1SIGMA(g)+O2 and a1DELTA(g)O2. The data are interpreted within the context of an exchange mechanism for energy transfer.