A combined microwave, infrared, and computational investigation of CHBrF2 is reported. For the vibrational ground state, measurements in the millimeter- and sub-millimeter-wave regions for CH79BrF2 and CH81BrF2 provided rotational and centrifugal-distortion constants up to the sextic terms as well as the hyperfine parameters (quadrupole-coupling and spin-rotation interaction constants) of the bromine nucleus. The determination of the latter was made possible by recording of spectra at sub-Doppler resolution, achieved by means of the Lamb-dip technique, and supporting the spectra analysis by high-level quantum chemical calculations at the coupled-cluster level. In this context, the importance of relativistic effects, which are of the order of 6.5% and included in the present work using second-order direct perturbation theory, needs to be emphasized for accurate predictions of the bromine quadrupole-coupling constants. The infrared measurements focused on the ν4 fundamental band of CH79BrF2. Fourier transform investigations using a synchrotron radiation source provided the necessary resolution for the observation and analysis of the rotational structure. The spectroscopic parameters of the v4 ) 1 state were found to be close to those of the vibrational ground state, indicating that the ν4 band is essentially unaffected by perturbations.
G. Cazzoli, L. Cludi, C. Puzzarini, P. Stoppa, A. Pietropolli Charmet, N. Tasinato, et al. (2011). Microwave, High-Resolution Infrared, and Quantum-Chemical Investigations of CHBrF2: the Ground and v4 =1 States. JOURNAL OF PHYSICAL CHEMISTRY. A, MOLECULES, SPECTROSCOPY, KINETICS, ENVIRONMENT, & GENERAL THEORY, 115, 453-459 [10.1021/jp110510v].
Microwave, High-Resolution Infrared, and Quantum-Chemical Investigations of CHBrF2: the Ground and v4 =1 States
CAZZOLI, GABRIELE;CLUDI, LINO;PUZZARINI, CRISTINA;
2011
Abstract
A combined microwave, infrared, and computational investigation of CHBrF2 is reported. For the vibrational ground state, measurements in the millimeter- and sub-millimeter-wave regions for CH79BrF2 and CH81BrF2 provided rotational and centrifugal-distortion constants up to the sextic terms as well as the hyperfine parameters (quadrupole-coupling and spin-rotation interaction constants) of the bromine nucleus. The determination of the latter was made possible by recording of spectra at sub-Doppler resolution, achieved by means of the Lamb-dip technique, and supporting the spectra analysis by high-level quantum chemical calculations at the coupled-cluster level. In this context, the importance of relativistic effects, which are of the order of 6.5% and included in the present work using second-order direct perturbation theory, needs to be emphasized for accurate predictions of the bromine quadrupole-coupling constants. The infrared measurements focused on the ν4 fundamental band of CH79BrF2. Fourier transform investigations using a synchrotron radiation source provided the necessary resolution for the observation and analysis of the rotational structure. The spectroscopic parameters of the v4 ) 1 state were found to be close to those of the vibrational ground state, indicating that the ν4 band is essentially unaffected by perturbations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
