Intermolecular Dynamics and Structure of Carbon Disulfide in Isoviscous Alkane Solutions:  An Optical Kerr Effect Study

Abstract

Optical Kerr effect spectroscopy has been used to study mixtures of CS 2 with 2-methylhexane and with n-hexane, in each case at a temperature at which the two components and all of their mixtures at different volume fractions have the same viscosity. Obtaining data in isoviscous mixtures allows us to make a direct comparison of orientational and intermolecular dynamics as a function of the CS 2 volume fraction, as well as to gain insight into the structure of the mixtures. In both cases the inhomogeneity in the intermolecular spectrum is found to stay roughly constant and the intermolecular potential to soften as the CS 2 volume fraction is decreased.

Molecular dynamics investigation with the time resolved optical Kerr effect on the CS2–C6H6 mixtures

“…In this case a "noninteracting" solvent is often chosen as the second com- ponent, ideally one which hardly contributes to the OHD-OKE signal. 20,27,31 The second motive is to understand better the dynamics of liquid mixtures themselves, in which case it is interesting to choose components that present appreciable interactions, and that is the trend we want to follow. Figure 4 shows the OHD-OKE transient signals for a series of decreasing benzene molar fraction mixtures in carbon disulfide.…”

“…In the recent past, many papers were published concerning investigations of the dynamics of pure simple liquids, such as carbon disulfide and benzene. [2][3][4][5] The aim of those investigations was to disclose the dynamical behavior underlying the molecular motions in liquids. Neat liquid systems were extensively studied under the limitations of optical Kerr effect ͑OKE͒ and, therefore the picture of a molecular probe has added new perspectives into the intermolecular dynamics.…”

“…These studies are mostly associated with investigations of a strongly anisotropic component ͑i.e., CS 2 or C 6 H 6 ͒ diluted in an isotropic solvent ͑such as CCl 4 and alkanes͒. 2,4,[20][21][22] In this situation, the analysis of the spectra is simplified by the fact that only reorientational fluctuations of the anisotropic component contribute to the spectra of the mixtures. On the other hand, the OHD-OKE transient signal of CS 2 -C 6 H 6 mixtures appear as a sum of the contributions of the "total permanent" as well as of the "interaction induced" polarizability anisotropies arising from fluctuations of each liquid, complicating the results analysis.…”

Factorized time correlation diagram analysis of Raman induced Kerr effect spectroscopy using noisy light

“…͓RIKES is often used synonymously with the term optical Kerr effect ͑OKE͒ spectroscopy in the modern literature.͔ The initial use of ultrashort pulses to study such phenomena began in the 1980s [1][2][3][4][5][6][7] and much work is still being done. [8][9][10][11][12][13][14][15][16][17] Optical heterodyne detected RIKES ͑OHD-RIKES͒ is one on the primary methods currently in use to study liquid phase dynamics. [8][9][10][11][12][13][14][15][16][17] There are still many open questions dealing with how reorientational energy is distributed among the inter-and intramolecular modes.…”

“…[8][9][10][11][12][13][14][15][16][17] Optical heterodyne detected RIKES ͑OHD-RIKES͒ is one on the primary methods currently in use to study liquid phase dynamics. [8][9][10][11][12][13][14][15][16][17] There are still many open questions dealing with how reorientational energy is distributed among the inter-and intramolecular modes. The open questions along with the experimental and theoretical aspects of OHD-RIKES are the subject of an excellent and very recent review.…”