Raman spectroscopy rotational isomerism

Selected physical properties of chloroprene are Hsted in Table 1. When pure, the monomer is a colorless, mobile Hquid with slight odor, but the presence of small traces of dimer usually give a much stronger, distinctive odor similar to terpenes and inhibited monomer may be colored from the stabilizers used. Ir and Raman spectroscopy of chloroprene (4) have been used to estimate vibrational characteristics and rotational isomerization. 

Keywords /er/-Butyldisilane / Rotational Isomerism / Raman Spectroscopy /... 

It is well known that variable-temperature Raman spectroscopy is a useful technique for the investigation of the rotational isomerism of substituted di- or oligosilanes as the frequencies of skeletal modes are usually highly sensitive to the conformation around Si-Si bonds. Energy differences between rotational Isomers can then be determined from variable-temperature spectra by applying van t Hoff s equation ... 

To observe particular rotational isomeric states, the method must be much more rapid than the rate of conformational isomerization. Optical methods such as absorption spectroscopy or light-scattering spectroscopy provide a short-time probe of the molecular conformation. If the electronic states of the molecule are strongly coupled to the backbone conformation, the ultraviolet or visible spectrum of the molecule can be used to study the conformational composition. The vibrational states of macromolecules are often coupled to the backbone conformation. The frequencies of molecular vibrations can be determined by infrared absorption spectroscopy and Raman scattering spectroscopy. The basic principles of vibrational spectres-... 

Rotational isomerism and Raman spectroscopy are historically related. The trans/gauche rotational isomerism with respect to a C—C single bond was discovered by Mizushima et al. 

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