The vibrational deactivation of N2(v=1) by H2 and HD at low temperatures

Rate constants have been measured for the vibration-to-translation deactivation of 14N2(v=1) and 15N2(v=1) by H2 and HD between 55–200 K. It is concluded that near-resonant (VR) coupling does not occur with H2, but is significant for 15N2 deactivated by HD above 100 K. Below 70 K, the rate constants for the deactivation of N2(v=1) continue to fall with temperature, in contrast to those for the deactivation of CO(v=1) by the same collision partners. Since the well-depths for the two cases are similar, the anisotropy of the attractive well must be important in governing low temperature rate constants.