Branching and rate coefficients of the HBr+Â +Â HBr reaction through the isotope-resolved REMPI technique

The charge-, atom- and proton-transfer channels of the HBr+ + HBr reaction have been studied at low temperature in an HBr + Ar free jet. Exploring ordinary HBr gas with the natural H79Br + H81Br (1:1) isotope abundance, the H79Br+ and H81Br+ ions in specific spin-orbit and vibrational states were prepared by resonance multiphoton ionisation in an isotope-selective manner that gave the opportunity to analyse reaction branching ratios and mechanisms.