Lifetime and deactivation of NH and ND (A 3Π, v=0 and 1)

A reinvestigation of the lifetime of NH(A,v=0) using ArF laser photolysis of NH3 to produce NH(A) is reported. In addition, the lifetime of NH(A,v=1) and ND(A,v=0 and 1) have been investigated. The lifetime of NH(A,v=0,J=8–12) is 424±8 ns and that for NH(A,v=1,J=4–6) is 461±10 ns. The lifetimes of protonated and deuterated A 3Π imidogen are the same within 5% suggesting no predissociation of the low rotational levels. Rate constants for quenching of NH/ND(A,v=0) and for deactivation of NH/ND(A,v=1) for a few selected collision partners have been measured and no isotope effect is found. The results of this work supersede those reported previously from this laboratory as the latter contain a small uncorrected systematic error.