Vibrational spectra and normal coordinate analysis of bromochlorofluoromethane

Stohner

2001

Chirality

We introduce the topic of fundamental symmetries of physics in relation to molecular chirality by a brief review of the development and current status of the theory of parity violation in chiral molecules. We then discuss in some detail CHBrClF (bromochlorofluoromethane) as a test case, to which the work of André Collet has contributed importantly. For this molecule and its isotopomers, we report here the first detailed theoretical calculations of the influence of parity violation on statistical thermodynamic properties. High-quality ab initio calculations (RPA, random phase approximation, and CASSCF, complete-active-space self-consistent-field) were performed to determine the small energy difference between R- and S-enantiomers of H and D isotopomers of bromochlorofluoromethane (CHBrClF, CDBrClF), and fluorooxirane ((1)H(3)C(2)OF) introduced by the parity-violating weak interaction. Together with vibrational and rotational frequency shifts caused by parity violation, these were used to determine the statistical thermodynamic quantities from the corresponding partition functions within the separable harmonic and in part also anharmonic adiabatic approximation. Temperature-dependent equilibrium constants for the stereomutation were calculated and are discussed in relation to biochemical homochirality.

Section: Chbrclf: Chemistry High Resolution Spectroscopy and Paritymentioning

confidence: 99%

Molecular chirality and the fundamental symmetries of physics: Influence of parity violation on rovibrational frequencies and thermodynamic properties

Stohner

2001

Chirality

“…[51] In addition, CDBrClF has been investigated together with CHBrClF in the fundamental region at lower resolution. [52][53][54] Studies of its vibrational circular dichroism [55] and its Raman optical activity [56] have been reported. This molecule has also been investigated to study the effects of coupled anharmonic vibrations on molecular parity violation.…”

mentioning

confidence: 99%

High Resolution Rovibrational Spectroscopy of Chiral and Aromatic Compounds

Albert

2007

ChemPhysChem

The analysis of selected rovibrationally resolved infrared spectra of some relatively heavy and large polyatomic molecules is reviewed. A short historical summary of the development of high resolution interferometric Fourier transform infrared (FTIR) spectrometers is given and the possibilities of the currently most highly resolving FTIR spectrometer, which is commercially available in the Bruker IFS 125 series, are discussed. The computational tools necessary to analyse FTIR spectra are described briefly. As examples of rovibrational analysis the spectra of three selected molecules CHCl(2)F, CDBrClF, and pyridine (C(5)H(5)N) are discussed. The spectrum of CHCl(2)F, a fluorochlorohydrocarbon, is of interest for a better understanding of the chemistry of the Earth's atmosphere. CDBrClF is a chiral molecule and therefore the analysis of its rovibrational spectra provides the basis for carrying out further experiments towards the detection of molecular parity violation. The analysis of the pyridine FTIR spectra illustrates the potential of the new generation of FTIR spectrometers in the study of spectra and rovibrational dynamics of aromatic systems and molecules of potential biological interest.

“…The vibrational spectrum of CDBrClF has been analyzed from the FIR to the NIR region (Beil et al 2000). In addition, CDBrClF has been investigated together with CHBrClF in the fundamental region at lower resolution (Diem and Burow 1976, 1977, Diem et al 1978. Studies of its vibrational circular dichroism (Marcott et al 1977) and its Raman optical activity (Prasad and Burow 1979) have been reported.…”

Section: Overview Of the Articlementioning

confidence: 99%

High‐Resolution Fourier Transform Infrared Spectroscopy

Albert

Handbook of High‐resolution Spectroscopy

2011

Recent developments and applications of high‐resolution Fourier transform spectroscopy are reviewed. A short historical summary of the development of high‐resolution interferometric Fourier transform infrared (FTIR) spectrometers is given and the possibilities of the currently most highly resolving FTIR spectrometers, including a current prototype built for the Zürich group at the Swiss Light Source SLS as a synchrotron light source, are discussed. A short description of the principles of FTIR spectroscopy is given and the resolution of current spectrometers is illustrated by FTIR spectra of CO, CO 2 OCS, N 2 O, CS 2 , and CH 4 and its isotopomers. The computational tools necessary to analyze FTIR spectra are described briefly. As examples of rovibrational analysis of more complex spectra, selected molecules CHCl 2 F, CDBrClF, pyridine (C 6 H 5 N) and pyrimidine (C 4 H 4 N 2 ), and naphthalene (C 10 H 8 ) are discussed. The spectrum of CHCl 2 F, a fluorochlorocarbon, is of interest for a better understanding of the chemistry of the Earth's atmosphere. It also possesses an isotopically chiral isotopomer CH 35 Cl 37 ClF analyzed in natural abundance. CDBrClF is a chiral molecule and therefore the analysis of its rovibrational spectra provides the basis for carrying out further experiments toward the detection of molecular parity violation. The analyses of the pyridine, pyrimidine, and naphthalene FTIR spectra illustrate the potential of the new generation of FTIR spectrometers in the study of spectra and rovibrational dynamics of aromatic systems and molecules of potential biological interest. In particular, naphthalene is a prototype molecule useful in gaining an understanding of the unidentified infrared bands (UIBs) detected in several interstellar objects.