Exchange Reactions in Selectively Excited Br2 (B3Piou+)

Laser - controlled bimolecular isotopic exchange reactions in bromine leading to alterations in natural isotopic abundance ratios have been directly observed using laser - modulated molecular beams and mass analysis. Several instances of selective excitation and subsequent rapid isotope exchange are observed within the 7 GHz gain curve of the exciting 514.5 nm line of an argon-ion laser. These exchange processes are attributed to the direct photochemical participation of excited molecular states in the B3Piou+ system of Br2.