Competition between the hydrogen bond and the halogen bond in a [CH3OH–CCl4] complex: a matrix isolation IR spectroscopy and computational study

Halogen bonding interaction (X-Bond) is prevalent over hydrogen bonding (H-Bond) interaction in [CH3OH–CCl4] mixtures/clusters: consequence in polar/non-polar mixtures and/or corresponding complexes in atmosphere needs to be investigated.

Solution thermodynamics and preferential solvation of 3-chloro-N-phenyl-phthalimide in acetone + methanol mixtures

The thermodynamic properties of the 3-chloro-N-phenyl-phthalimide in acetone+ methanol cosolvent mixtures were obtained from solubility data report in literature. The solubility was higher in near acetone and lower in pure methanol at all temperatures studied. A non-linear plot of ∆ from pure acetone up to x 1 soln H° vs. ∆ soln 2, Gerson G° shows a negative slope = 0.691. Beyond this composition, a variable positive slope is obtained with the exception of mixtures with x 1 = 0.121, x1 = 0.272 and x 1= 0.356 which is a not common trend in these systems. The preferential solvation of 3-chloro-N-phenyl-phthalimide by the components of the solvents was estimated by means of the inverse Kirkwood–Buff integral method, showing the 3-chloro-Nphenyl-phthalimide is preferential solvated bymethanol in more polar mixtures and by acetone in less polar ones.

Relaxation phenomena of nicotinamide and benzamide with 1-propanol and 1-butanol in C6H6 under static and 9.385 GHz electric field

Dielectric relaxation behaviors of nicotinamide+1-propanol, benzamide+1-propanol, and nicotinamide+1-butanol dissolved in C6H6 at 0.990, 0.985, 0.980, 0.975, 0.970; 0.990, 0.985, 0.980, and 0.980 mol fraction xj of 1-propanol or 1-butanol at temperature 30 °C and 30, 40, 50, and 60 °C, respectively, are studied using the Debye model of binary polar–non-polar liquid mixture to predict double relaxation times τ2 and τ1 and dipole moments μ2 and μ1 from susceptibility measurement of concentration variation solution data under static and 9.385 GHz electric fields. Nineteen systems exhibit τ2, τ1 and μ2, μ1. τ2 are found to increase with temperature for all the binary polar mixtures, whereas τ1, most probable τ0, and measured τ from slope methods are almost the same. They agree well with the τ reported by Higasi. The plots of τjk–xj and μjk–xj curves reveal solute–solute and solute–solvent molecular association through H-bonding, and variation of μ with t (°C) is noted from the μjk–t curve. The associational aspects are taken into consideration from theoretical μtheo from the standpoint of inductive, mesomeric, and electromeric effects within the polar groups of the molecules. The estimated Debye factor τjkT/η and Kalman factor τjkT/ηγ reveal that the polar mixture obeys the Debye relaxation mechanism.

Comparative Study of Linear Co-Volume Based Mixing Rules for Equation of State/ Excess Gibbs Energy (EOS/GE) Models for CO2 – MEA and CO2 – MDEA Systems

With the advent of Equation of State/ Excess Gibbs Energy (EOS/GE) models, the linear co-volume based mixing rules have gained vast importance for predicting multi-component VLE for polar mixtures. Owing to their inherent ease of calculation and good prediction abilities, these mixing rules have been applied in extension, to a variety of systems especially for CO2-H2O-alkanolamine systems. However, no comparative study is available to select appropriate mixing rule for prediction of thermodynamic properties. In this study, pressure prediction of various linear co-volume mixing rules has been compared for CO2– MEA and CO2– MDEA systems, while effects of activity coefficients and process parameters have been kept constant. The infinite pressure mixing rules have heavily under – predicted and approximate zero reference pressure mixing rules have over – predicted, but latter are valid for low and medium pressure ranges. The linear combination of Vidal and Michelsen (LCVM) mixing rule have good predictions at high pressures.