Rotation-vibration spectrum of hydrazoic acid in the near infra-red and in the visible

Abstract

Second and third overtones of N-H stretching vibration in HN3 have been investigated at higher rcsolving power and pathlength than previously, and the fourth overtone photographed for the first time. The rotational analysis of 3v1, where more than 500 lines were measured, gives accurate values of the rotational constants of both ground and upper states. A local perturbation was found in levels with K' = 2 and 4. The rotational analysis of 4v1, where lines are broader than in 3vl, indicates that the dependence of A from vibrational quantum number ul, is not linear. Owing to the large linewidth (-0.35 cm-') only the analysis of the K-structure is possible for 5vl. The diffuseness in 4vl and 5vl is discussed in terms of line broadening by case I1 predissociation.

Using Vector Correlation To Probe the Influence of Vibrational State Selection on the Photodissociation Dynamics of HN3

“…al. 12 at medium resolution appears to support this notion, and although their analysis reveals local perturbations in the spectra of the 3ν 1 level involving rotational states of the K a ) 2 and K a ) 4 stacks the other K stacks appear to be clean. In the present experiment the 0.4 cm -1 resolution of the IR laser results in the excitation of a range of rotational transitions within the 3ν 1 level.…”

“…The spectral analysis of Carlotti et. al . at medium resolution appears to support this notion, and although their analysis reveals local perturbations in the spectra of the 3ν 1 level involving rotational states of the K a = 2 and K a = 4 stacks the other K stacks appear to be clean.…”

“…In many ways the HN 3 molecule is an ideal system for investigating vibrationally mediated photodissociation. Its single-photon dissociation dynamics has been studied extensively at several different UV wavelengths, − its vibrational spectroscopy is well characterized, − and even its unimolecular decomposition has been investigated . In addition, several theoretical studies have been reported on HN 3 that address various aspects of the topology of its ground and low lying excited electronic potential energy surfaces. , Ab-initio calculations by Meier and Staemmler 17 show that for UV photolysis wavelengths longer than 220 nm the lowest excited singlet electronic surface, the 1 1 A‘‘ state, controls the photochemistry of HN 3 .…”

“…In many ways the HN 3 molecule is an ideal system for investigating vibrationally mediated photodissociation. Its single-photon dissociation dynamics has been studied extensively at several different UV wavelengths, 6-11 its vibrational spectroscopy is well characterized, [12][13][14] and even its unimolecular decomposition has been investigated. 15 In addition, several theoretical studies have been reported on HN 3 that address various aspects of the topology of its ground and low lying excited electronic potential energy surfaces.…”