Journal article

Publication year: 2009

Pages: 10385-10390

Journal: Physical Chemistry Chemical Physics

Volume number: 11

Issue number: 44

ISSN: 1463-9076

DOI Link: https://doi.org/10.1039/B912803D

Publisher: Royal Society of Chemistry

Abstract: 

The first definitive infrared signatures of the elusive NCCO radical
have been measured using a microwave discharge technique combined with
low-temperature matrix-isolation spectroscopy, resulting in a consistent set of vibrational assignments for six isotopologues. The infrared spectra
of these NCCO isotopologues were concomitantly established by rigorous
variational nuclear-motion computations based on a high-level
coupled-cluster quartic vibrational force field [ROCCSD(T)/cc-pCVQZ] and
cubic dipole field [ROCCSD/cc-pCVTZ]. Our experimental and theoretical
results for NCCO overturn the vibrational assignments in a NIST-JANAF
compilation and those from a recent two-dimensional cross-spectral
correlation analysis. For the parent isotopologue at 11 K in a nitrogen matrix, we find the signature bands ν₂(CO str.) = 1889.2 cm⁻¹ and ν₃(CC str.) = 782.0 cm⁻¹. Our variational vibrational computations reveal strong mixing of the ν₃ stretching fundamental and the ν₄ + ν₅
bending combination level for all isotopologues. These Fermi resonances
manifest a clear breakdown of the simple normal-mode picture of
molecular vibrations at low energies.

Harvard Citation style: Schreiner, P., Reisenauer, H., Matyus, E., Császár, A., Siddiqi, A., Simmonett, A., et al. (2009) Infrared signatures of the NCCO radical, Physical Chemistry Chemical Physics, 11(44), pp. 10385-10390. https://doi.org/10.1039/B912803D

APA Citation style: Schreiner, P., Reisenauer, H., Matyus, E., Császár, A., Siddiqi, A., Simmonett, A., & Allen, W. (2009). Infrared signatures of the NCCO radical. Physical Chemistry Chemical Physics. 11(44), 10385-10390. https://doi.org/10.1039/B912803D