Laser-induced fluorescence study of spin-orbit quenching of Cl(2P1/2) by H2, D2, and HD gases

► Rate constants for Cl atom spin-orbit quenching by H2, D2, HD were measured. ► Spin-orbit excited Cl atoms were detected by VUV laser-induced fluorescence. ► Kinetic isotope effects are attributed to near-resonant ER energy transfer processes.