Measurement of fracton dimensionality in liquids by four-photon Rayleigh-wing spectroscopy

Four-photon spectroscopy of the Rayleigh wing was applied to study distilled and Milli-Q water, liquid carbon tetrachloride (CCl4), 30% aqueous solution of hydrogen peroxide (H2O2) and 0.4 mm aqueous solution of a-chymotrypsin protein, in the spectral range from -10 to 10 cm(-1). The observed spectra allowed the measurement of the fracton dimensionality as d = 2.87 +/- 0.01 in Milli-Q water, 2.97 +/- 0.02 in the protein solution, 3.00 +/- 0.02 in CCl4 and H2O2 and 3.15 +/- 0.05 in distilled water. The variation of fractal dimensionality can be interpreted as indication of the structural differences in the investigated liquids. In the presence of protein and hydrogen peroxide molecules, this difference indicates that the hydrogen-bond network of Milli-Q water is restructured in the solution. Copyright (c) 2006 John Wiley & Sons, Ltd.