<title>Temperature shifts of phenanthrene S<formula><inf><roman>2</roman></inf></formula>-S<formula><inf><roman>0</roman></inf></formula> spectrum in apolar solvents and in water</title>

Abstract

Phenanthrene, a three ring aromatic hydrocarbon, is used as a model substance for study of intermolecular interactions in dilute solutions of organic solvents and water by spectroscopic method. Temperature dependencies of shift of the S2 - SO spectrum of phenanthrene dissolved in apolar solvents and in liquid water are studied in this work. The spectroscopic data are used for analysis of the cavity radius R for phenanthrene molecule in solvents. It is shown that the value of R increases with temperature in organic solvents. In contrast, for water solution, the value ofR initially grows with temperature increase (in the interval of 273.3-296 K), but becomes constant at higher temperatures. The changes of water structure in the neighbourhood of a phenanthrene molecule and probable hypothesis about causes of R value constancy in high-temperature region are discussed. Conclusion about strengthening ofthe water structure in an aqueous cage with phenanthrene molecule inside is done.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.