Ring-down cavity absorption spectroscopy of the very weak HCN overtone bands with six, seven, and eight stretching quanta

Romanini, D.; Lehmann, K. K.
November 1993
Journal of Chemical Physics;11/1/1993, Vol. 99 Issue 9, p6287
Academic Journal
A nonstandard, high sensitivity, absorption detection technique has been applied to the investigation of the very weak fifth, sixth, and seventh overtones of HCN at 100 Torr and 296 K. The frequency range covered is from 17 500 to 23 000 cm-1. We report high resolution, absolute absorption spectra with a noise equivalent sensitivity as low as ∼2×10-9/cm (recently improved to 7×10-10/cm). Band origins, rotational constants, and band intensities are reported and compared with calculated values. The HCN overtone spectra in the present study are not affected by any kind of perturbation, despite the high excitation energy involved.


Related Articles

  • Trajectory studies of unimolecular reactions of Si2H4 and SiH2 on a global potential surface fitted to ab initio and experimental data. Agrawal, Paras M.; Thompson, Donald L.; Raff, Lionel M. // Journal of Chemical Physics;7/15/1988, Vol. 89 Issue 2, p741 

    The unimolecular decomposition dynamics of Si2H4 have been investigated using classical trajectory methods on a global potential-energy surface fitted to the results of ab initio calculations and the available experimental data. The required phase-space averages are computed using Metropolis...

  • Unimolecular dynamics following vibrational overtone excitation of HN3 v1=5 and v1=6: HN3(X;v,J,K)→HN(X 3Σ-;v,J,Ω)+N2 (X 1Σ+g). Foy, B. R.; Casassa, M. P.; Stephenson, J. C.; King, D. S. // Journal of Chemical Physics;7/1/1988, Vol. 89 Issue 1, p608 

    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...

  • State-specific unimolecular reaction dynamics of HFCO. I. Dissociation rates. Choi, Young S.; Moore, C. Bradley // Journal of Chemical Physics;7/15/1992, Vol. 97 Issue 2, p1010 

    Rovibrationally resolved unimolecular reaction rates of highly vibrationally excited HFCO (S0) are measured and found to be strongly state specific in the energy range of 14 500 cm-1–23 000 cm-1. HFCO molecules are excited to single rovibrational levels in the tunneling region by...

  • A new technique for state-to-state studies of unimolecular reactions. Luo, X.; Rieger, P. T.; Perry, D. S.; Rizzo, T. R. // Journal of Chemical Physics;10/1/1988, Vol. 89 Issue 7, p4448 

    A double-resonance technique which combines infrared excitation of a fundamental vibration of a light atom oscillator with vibrational overtone excitation of that same oscillator selectively prepares molecules in individual quasibound vibrational–rotational states at energies above their...

  • Formation mechanism of polycyclic aromatic hydrocarbons in benzene combustion: Quantum chemical molecular dynamics simulations. Saha, Biswajit; Irle, Stephan; Morokuma, Keiji // Journal of Chemical Physics;6/14/2010, Vol. 132 Issue 22, p224303 

    High temperature quantum chemical molecular dynamics simulations on the polycyclic aromatic hydrocarbon (PAH) formation during combustion of benzene were performed using the density-functional tight-binding (DFTB) method. Systems with varying H/C of 0.8, 0.6, 0.4, and 0.2 and temperatures of...

  • Nonstatistical inversion dynamics of T-shaped Ar3. Dumont, Randall S.; Jain, Shashi // Journal of Chemical Physics;7/15/1992, Vol. 97 Issue 2, p1227 

    Numerical computations reveal nonstatistical characteristics of microcanonical T-shaped Ar3 inversion at energies associated with strongly chaotic dynamics. Nonstatisticality is most pronounced at higher energies where internal relaxation time scales are comparable to the inversion time. At such...

  • Method for predicting IVR-limited unimolecular reaction rate coefficients. Shalashilin, Dmitrii V.; Thompson, Donald L. // Journal of Chemical Physics;10/22/1997, Vol. 107 Issue 16, p6204 

    Focuses on intramolecular dynamics diffusion theory based on diffusion theory for calculating unimolecular reaction rates at high energies where reaction is limited by the intramolecular vibrational energy redistribution rate. Use of short-time classical trajectory results to determine the...

  • State-to-State unimolecular reaction dynamics of HOCl neat the dissociation threshold: The role... Callegari, A.; Rebstein, J. // Journal of Chemical Physics;10/22/1999, Vol. 111 Issue 16, p7359 

    Studies state-to-state unimolecular reaction dynamics of hypochlorous acid (HOCl) molecules in rotational levels of high OH stretching states. Monitoring of the dependence of unimolecular dissociation rate on the angular momentum, total energy and vibrational character of the state of the...

  • On the classical theory of the rate of isomerization of HCN. Tang, Hui; Jang, Soonmin; Zhao, Meishan; Rice, Stuart A. // Journal of Chemical Physics;11/15/1994, Vol. 101 Issue 10, p8737 

    We report the results of calculations, using classical mechanics, of the rate of the isomerization reaction HCNCNH. The three purposes of the calculations are (i) to test whether or not the Zhao–Rice approximate version of the Davis–Gray theory provides an accurate description of...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics