Infrared Spectroscopy Of The V(1) + V(4) And 3v(4) Bands Of The Nitrate Radical

High-resolution Fourier transform infrared spectra of the v(1) + v(4) and 3v(4) bands of (NO3)-N-14 were observed in the 1414 and 1174 cm(-1) regions, respectively, and the corresponding ones of (NO3)-N-15 in the 1407 and 1159 cm(-1) regions, respectively, and analyzed as E'-A'(2) bands. The rotational constants of the upper states of (NO3)-N-14 are determined to be 0.457584 and 0.46089 cm(-1) for v(1) + v(4) and 3v(4), respectively, consistent with the vibrational assignment. Effective Coriolis coupling constants of the ground electronic state are partly explained by vibronic interaction from the (BE)-E-2' state, and a large change (37% decrease) in the value of the v(1) + v(4) state compared with that of the v(4) state is attributed to a mixing with the v(3) + v(4) state (1492 cm(-1)) through vibrational anharmonicity. (C) 2018 Elsevier Inc. All rights reserved.