Infrared frequency-modulation measurements of absolute rate coefficients for Cl+HD→HCl(DCl)+D(H) between 295 and 700 K

Absolute rate coefficients and HCl branching fractions for the Cl+HD reaction have been measured. The rate coefficient for Cl+HD is fit well by k1=(1.28±0.18)×10−16 T1.67 e−(1646±60)/T cm3 molecule−1 s−1, approximately 30% smaller than the mean of literature rate coefficients for Cl+H2 and D2. The branching fraction into the HCl channel is 0.67±0.09 at 295 K and decreases at higher temperature. The present results agree well with literature measurements of relative rates, confirming different isotope effects in thermal conditions than in molecular beam measurements.