Coherent laser spectroscopy of molecular motions in liquids in the maser range

✍ Scribed by A. F. Bunkin; S. M. Pershin; A. A. Nurmatov; A. P. Gorchakov

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 157 KB
• Volume: 38
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/jrs.1678

✦ Synopsis

Abstract

The terahertz and subterahertz four‐photon spectroscopy of liquids gives the opportunity to study large volume samples in native conditions. We present the experimental measurements by this technique of the low‐wavenumber molecular motion in water and some aqueous solution. In fact, the coherent librations of H~2~O molecules in liquid water as well as aqueous solutions of H~2~O~2~ and a protein in the microwave range (0.1–100 cm^−1^) are observed. A satisfactory correlation of the observed resonances with the rotational spectra of H~2~O molecule in the gas phase is found. Moreover the lines of ortho‐ and para‐isomers of H~2~O molecule were identified. We have found that the protein molecules in water interact selectively with the spin isomers of H~2~O. There is a strong suppression of the rotational motion of the para‐isomers and their respective line intensities, with a corresponding magnification by a factor of 8 by the ortho species. Copyright © 2007 John Wiley & Sons, Ltd.