Spectroscopy of interparticle interactions in ionic and molecular liquids: Novel approaches

Abstract

The paper deals with several novel approaches to the studies of interactions and dynamics in liquids. A new, flexible time-correlation function is introduced. It has an analytical counterpart in the frequency domain and enables one to fit even badly overlapped vibrational line profiles obtaining dynamical information at the same time. As examples, quantitative description of the interaction potential in molten salts containing halide complexes of zinc and manganese is presented, the dynamic criterion of complex entities in a melt is introduced, and the spectroscopic features of molten alkali and alkaline earth halides are explained in terms of short-lived collision complexes. Finally, the model treatment of "anomalous" noncoincidence effects in liquids is discussed, and the contribution of repulsion and attraction forces resulting in frequency non-coincidences is separated.

Recovery of the depolarization ratio of single lines from overlapping isotropic and anisotropic Raman profiles and assignment of molecular vibrations, with special reference to toluene and toluene‐d8

“…In the past, such studies have been performed mainly with I iso , and a large body of data regarding time-correlation functions of vibrational relaxation in liquids and glasses has been accumulated and analyzed. 5,6 Successful application of this algorithm to I aniso will enable one to model time-correlation functions of rotational relaxation. Problem-related comparative analysis of toluene and toluene-d 8 in the liquid state will be published elsewhere.…”

Possible spectroscopic manifestation of the angular group induced bond alteration (AGIBA) effect in toluene

“…This method has been successfully employed in numerous applications, 13,14 especially in studies of overlap lines since, unlike other methods that are empirical in nature, its theoretical basis is obvious. Its only limitation lies in the fact that vibrational line profiles at issue are considered symmetric.…”

Speciation in Solutions of Lithium Salts in Dimethyl Sulfoxide, Propylene Carbonate, and Dimethyl Carbonate from Raman Data: A Minireview

“…is the speed of light, ] 0 is the wavenumber of the line maximum, 1 and 2 are certain parameters, and 1 ( ) is the modified Bessel function of the second kind. This expression is more flexible than the commonly used Voight function and is widely used for the decomposition of overlap lines [43]. In order to find the dependence of the amount of particles present in solutions on the concentration of lithium salts, = ( salt ), it was considered that values are proportional to integrated intensities of isotropic lines.…”

“…[51] the absence of free ions in solutions of lithium salts in carbonate solvents and to prove the statement that the charge transfer in carbonate solutions is caused by SSIPs is an analysis of vibrational dynamics in the systems studied. To do so one has to use an approach based on time-correlation functions (TCFs) of vibrational dephasing described in detail in [42,43]. TCFs ( ) can be obtained by means of Fourier transforms of Raman spectra (]):…”