Effects of molecular association on mutual diffusion: A study of hydrogen bonding in dilute solutions

Abstract

Influence of solute-solvent coordination on the orientational relaxation of ion assemblies in polar solvents J. Chem. Phys. 136, 014501 (2012) Theoretical study of the aqueous solvation of HgCl2: Monte Carlo simulations using second-order Moller-Plessetderived flexible polarizable interaction potentials J. Chem. Phys. 136, 014502 (2012) A two-dimensional-reference interaction site model theory for solvation structure near solid-liquid interface J. Chem. Phys. 135, 244702 (2011) On the solvation structure of dimethylsulfoxide/water around the phosphatidylcholine head group in solution JCP: BioChem. Phys. 5, 12B611 (2011) Additional information on J. Chem. Phys. Diffusivities of pseudoplanar molecules at trace concentration in methanol have been measured at 298.2 K using Taylor's dispersion method. The data of the polar and nonpolar aromatic solutes are compared, and the effects due to solute-solvent interactions on diffusion, together with the solvation numbers, are determined. In this study, the effects are combined with the recently developed solute hydrogen-bond scales to unravel hydrogen bonding between solute and solvent. It is found that the degrees of association of the solutes with methanol decrease in the sequence hydroquinoneϾaromatic acidsϾphenolsϾaromatic aminesϾaprotic aromatic compounds. Except for o-nitrophenol, which is capable of intramolecular hydrogen bonding, all aromatic acids, phenols, and amines studied behave more as hydrogen-bond donor than acceptor in methanol. The present work also indicates that motions of associated molecules can be understood in terms of the molecular behavior of nonassociated solutes and the hydrogen-bond acidity/basicity of polar solutes.

Diffusion of aromatic compounds in nonaqueous solvents: A study of solute, solvent, and temperature dependences

“…The uncertainty listed is the average absolute error. The reproducibility of data here is consistent with those reported in our previous works [33][34][35][36] using basically the same technique. In this study, we also report the tracer diffusivities of 1,2,4-trichlorobenzene and mesitylene in 1-butanol, which at 298.15 K are 0.730 ± 0.009 and 0.732 ± 0.008 × 10 −9 m 2 s −1 , respectively.…”

“…The present results are consistent with those found previously on the diffusivities of similar solutes in other solvents. 30,[32][33][34][35] The constants a and b for systems in this and previous works, together with their respective correlation coefficients and average % deviations of fit, are given in Table II. It is noteworthy that Eq.…”

“…Previously, we have reported the effects of molecular mass, 28,29 dipole moment, 28,29 shape, 29,30 and size 30,31 of solutes on diffusivities. Investigations of the effects of hydrogen-bonding [31][32][33][34][35] and the steric effects 36 of associated molecules on diffusion have also been published. In this work, we report new tracer diffusivities of some aromatic compounds in n-hexane and cyclohexane at 298.2 K. It should be noted that throughout this study the term tracer diffusivity refers to mutual diffusion coefficient of a solute at trace (very dilute) concentration in a molecular liquid, i.e., limiting mutual diffusion coefficient.…”

Molecular dynamics simulation of liquid methanol under the influence of an external electric field

“…Similar to water, methanol molecules are able to form hydrogen bonds among themselves, which are responsible for many of the abnormal properties of bulk solvent [1][2][3]. Since the first computer simulation of liquid methanol to determine the liquid structure were carried out by Jorgensen using the Monte Carlo method [4], much of the research effort has been devoted to examining the structural and dynamic properties of methanol and aqueous solution [5][6][7][8][9][10][11][12]. The changes of structural and dynamic properties of water and aqueous solutions under the influence of an external electric field are quite important regarding electrochemistry and biology [13].…”

The effect of hydrogen bonding on the diffusion of water in n-alkanes and n-alcohols measured with a novel single microdroplet method

“…This was in accordance with the results of studies, which also found a decrease in diffusion coefficient due to the possibility of hydrogen bonding between a diffusing solute and the surrounding solvent. 18,20,21,24,29,30 Interestingly, plotting the diffusion coefficients of water in the various alkanes and alcohols ͑Fig. 4͒ did reveal a fractional power viscosity dependence as expected for the diffusion of a small solute: D ϳ −␣ .…”