The vibrational deactivation of N-2(v = 1) by H-2 and HD at low temperatures

Rate constants have been measured for the vibration-to-translation deactivation of N-14(2)(upsilon = 1) and N-15(2)(upsilon = 1) by H-2 and HD between 55-200 K. It is concluded that near-resonant (VR) coupling does not occur with H-2, but is significant for N-15(2) deactivated by HD above 100 K. Below 70 K, the rate constants for the deactivation of N-2(upsilon = 1) continue to fall with temperature, in contrast to those for the deactivation of CO(upsilon = 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. (C) 1997 Elsevier Science B.V.