title: Photofragment translation spectroscopy of ClN3 at 248 nm: determination of the primary and secondary dissociation pathways.
abstract: Photofragmentation translational spectroscopy was used to identify the primary and secondary reaction pathways in the KrF laser (248 nm) photodissociation of chlorine azide (ClN(3)) under collision-free conditions. Both the molecular channel producing NCl (X (3)Sigma,a (1)Delta) + N(2) and the radical channel producing Cl ((2)P(J)) + N(3) were analyzed in detail. Consistent with previously reported velocity map ion imaging experiments [N. Hansen and A. M. Wodtke, J. Phys. Chem. A 107, 10608 (2003)] a bimodal translational energy distribution is seen when Cl atoms are monitored at mz = 35(Cl(+)). Momentum-matched N(3) counterfragments can be seen at mz = 42(N(3) (+)). The characteristics of the observed radical-channel data reflect the formation of linear azide radical and another high-energy form of N(3) (HEF-N(3)) that exhibits many of the characteristics one would expect from cyclic N(3). HEF-N(3) can be directly detected by electron-impact ionization more than 100 mus after its formation. Products of the unimolecular dissociation of HEF-N(3) are observed in the mz = 14(N(+)) and mz = 28(N(2) (+)) data. Anisotropy parameters were determined for the primary channels to be beta = -0.3 for the NCl forming channel and beta = 1.7 and beta = 0.4 for the linear N(3) and HEF-N(3) forming channels, respectively. There is additional evidence for secondary photodissociation of N(3) and of NCl.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Santa Barbara, 93106, USA. nhansen@sandia.gov
authors.forename: N
authors.initials: N
authors.lastname: Hansen
authors.forename: A M
authors.initials: AM
authors.lastname: Wodtke
authors.forename: S J
authors.initials: SJ
authors.lastname: Goncher
authors.forename: J C
authors.initials: JC
authors.lastname: Robinson
authors.forename: N E
authors.initials: NE
authors.lastname: Sveum
authors.forename: D M
authors.initials: DM
authors.lastname: Neumark