Near-Infrared Spectra of H2O—D2O Solutions

Publisher Website
Google Scholar
Abstract
Near‐infrared spectra have been obtained for HOD in D2O solutions containing a variety of solutes. A sharp band occurs at 1.416 μ (7062 cm−1) and other bands at 1.525 (6557 cm−1), 1.556 (6427 cm−1), and 1.666 μ (6002 cm−1). The absorbances at 1.416 and 1.556 μ increase and decrease, respectively, with increasing temperature. From this variation, a ΔH° of formation of −2.4 kcal/mole has been estimated for the O–H···O bond in these solutions. Nineteen electrolytes and one polymer, polyvinylpyrrolidone, have been examined for their effects on the spectra of water in this overtone region. No frequency shifts have been observed with added solute, only changes in absorbance. Sodium perchlorate shows the strongest structure‐breaking effect. Tetrabutylammonium bromide and polyvinylpyrrolidone exhibit structure‐making character. A definite correlation has been found to exist between the effects of salts on the aqueous solvent and their ability to affect the conformation of a macromolecule.