Unimolecular dynamics following vibrational overtone excitation of HN3 <i>v</i>1=5 and <i>v</i>1=6: HN3(<i>X</i>;<i>v</i>,<i>J</i>,<i>K</i>)→HN(<i>X</i> 3Σ−;<i>v</i>,<i>J</i>,Ω)+N2 (<i>X</i> 1Σ+<i>g</i>)

Abstract

Excitation of the NH-stretch overtone transitions of HN3 to v1=5 and 6 resulted in predissociation to HN(X) and N2(X) with lifetimes of 80+60−30 and ≤3 ns, respectively. Following excitation of either overtone, the HN fragments were formed predominantly in the symmetric F1, F3 spin–rotation states, with less than 4% population in the antisymmetric F2 levels. Fragment Doppler profiles confirmed that most of the available energy (&amp;gt;96%) went into translational motion.