Sulfoxide Binary Mixtures Research Articles

Understanding cellulose dissolution in ionic liquid-dimethyl sulfoxide binary mixtures: Quantification of the relative importance of hydrogen bonding and hydrophobic interactions

We studied the dissolution of microcrystalline cellulose (MCC) in mixtures of dimethyl sulfoxide (DMSO) with 32 ionic liquids (ILs), at a fixed temperature (70 °C) and mole fraction of DMSO (χDMSO = 0.6). Under these conditions, employing a recommended dissolution protocol, MCC dissolved in 19 IL-DMSO mixtures. In order to access quantitatively the relative importance (to biopolymer dissolution) of cellulose-solvent interactions, we correlated the mass fraction of dissolved cellulose (MCC-m%) with physicochemical properties of these mixtures. The solvent descriptors that gave the best correlations are Lewis acidity and Lewis basicity (calculated from the UV–Vis spectra of solvatochromic probes), the molar volume of the IL, and the Lorentz-Lorenz refractive index function of the IL-DMSO mixtures. This result is similar to that observed when solvent empirical polarities of these binary mixtures were correlated with the same descriptors. The multi-parameter correlations quantify, for the first time, the relative importance of cellulose-solvent interactions. Our results agree with the established opinion that an efficient cellulose solvent should disrupt the inter- and intramolecular hydrogen bonding in cellulose, and the hydrophobic interactions present due to the amphiphilic nature of the biopolymer.

Naphthalimide Imidazolium-Based Supramolecular Hydrogels as Bioimaging and Theranostic Soft Materials.

1,8-Naphthalimide-based imidazolium salts differing for the alkyl chain length and the nature of the anion were synthesized and characterized to obtain fluorescent probes for bioimaging applications. First, their self-assembly behavior and gelling ability were investigated in water and water/dimethyl sulfoxide binary mixtures. Only salts having longer alkyl chains were able to give supramolecular hydrogels, whose properties were investigated by using a combined approach of fluorescence, resonance light scattering, and rheology measurements. Morphological information was obtained by scanning electron microscopy. In addition, conductive properties of organic salts in solution and gel state were analyzed. Imidazolium salts were successfully tested for their possible application as bioimaging and cytotoxic agents toward three cancer cell lines and a nontumoral epithelial cell line. Characterization of their behavior was performed by MTT and cell-based assays. Finally, the biological activity of hydrogels was also investigated. Collectively, our findings showed that naphthalimide-based imidazolium salts are promising theranostic agents and they were able to preserve their biological properties also in the gel phase.

Comments on “Reply to comments on study of density, dynamic viscosity, excess property and intermolecular interplay studies for 1,4-butanediol + dimethyl sulfoxide binary mixture”

A polemic is given regarding the volumetric properties reported in the authors' reply to an earlier commentary. The recalculated partial molar volumes of the individual mixture components, given in the authors' reply, are found to be thermodynamically inconsistent with the experimental excess molar volumes.

Reply to “Comments on study of density, dynamic viscosity, excess property and intermolecular interplay studies for 1,4-butanediol + dimethyl sulfoxide binary mixture”

Reply to “Comments on study of density, dynamic viscosity, excess property and intermolecular interplay studies for 1,4-butanediol + dimethyl sulfoxide binary mixture”

Comment on “Density, dynamic viscosity, excess property and intermolecular interplay studies for 1,4-butanediol + dimethyl sulfoxide binary mixture”

A polemic is given regarding the calculated volumetric properties reported by Yue and coworkers for binary mixtures containing 1,4-butanediol and dimethyl sulfoxide. The calculated excess molar volumes reported by the authors for 293.15 K are not thermodynamically consistent with the calculated partial molar volumes of the mixture components. The calculated excess molar volumes at 293.15 K are negative, while the partial molar volumes suggest that the excess molar volumes should be positive. Thermodynamic inconsistencies were found at other temperatures as well.

Density, dynamic viscosity, excess property and intermolecular interplay studies for 1,4-butanediol + dimethyl sulfoxide binary mixture

The density (ρ) and kinematic viscosity (v) in the scope of T = (298.15 to 323.15) K were systemically studied for 1,4-butanediol (BDO) (1) + dimethyl sulfoxide (DMSO) binary mixture with various compositions at atmospheric pressure. From the ρ and v values, the dynamic viscosity (η) were also obtained. According to the above experimental values, viscosity deviation (∆η), excess molar volume (VmE), partial molar volumes (V1¯ and V2¯), apparent molar volume (Vφ,1 and Vφ,2) and isostatic pressing thermal expansion (αp) were determined. The ρ, VmE and ∆η values were fitted by using Jouyban-Acree model, Eyring equation, and Redlich-Kister equation, respectively. Additionally, the intermolecular interplay was analyzed using FTIR, NMR, and UV–vis spectra, which suggested the formation of hydrogen bonds between the hydroxyl H atoms in BDO and the O atoms in DMSO.

Influence of Non-Aqueous Solvents on Complexation and Selectivity of Complexes Formed Between 18-crown-6 with La3+, Ce3+, Pr3+ and Nd3+ cations in pure acetonitrile, pure dimethyl sulfoxide and acetonitrile-dimethyl sulfoxide binary mixtures at 298.15K, 308.15K and 318.15K using conductometric method

Influence of Non-Aqueous Solvents on Complexation and Selectivity of Complexes Formed Between 18-crown-6 with La3+, Ce3+, Pr3+ and Nd3+ cations in pure acetonitrile, pure dimethyl sulfoxide and acetonitrile-dimethyl sulfoxide binary mixtures at 298.15K, 308.15K and 318.15K using conductometric method

Viscosity Coefficients of KCl, NaCl, NaI, KNO3, LiNO3, NaBPh4 and Bu4NI in Water - Dimethyl Sulfoxide Binary Mixtures With a Low Organic Solvent Content

Viscosity Coefficients of KCl, NaCl, NaI, KNO3, LiNO3, NaBPh4 and Bu4NI in Water - Dimethyl Sulfoxide Binary Mixtures With a Low Organic Solvent Content

Solvation dynamics of tryptophan in water-dimethyl sulfoxide binary mixture: In search of molecular origin of composition dependent multiple anomalies

Experimental and simulation studies have uncovered at least two anomalous concentration regimes in water-dimethyl sulfoxide (DMSO) binary mixture whose precise origin has remained a subject of debate. In order to facilitate time domain experimental investigation of the dynamics of such binary mixtures, we explore strength or extent of influence of these anomalies in dipolar solvation dynamics by carrying out long molecular dynamics simulations over a wide range of DMSO concentration. The solvation time correlation function so calculated indeed displays strong composition dependent anomalies, reflected in pronounced non-exponential kinetics and non-monotonous composition dependence of the average solvation time constant. In particular, we find remarkable slow-down in the solvation dynamics around 10%-20% and 35%-50% mole percentage. We investigate microscopic origin of these two anomalies. The population distribution analyses of different structural morphology elucidate that these two slowing down are reflections of intriguing structural transformations in water-DMSO mixture. The structural transformations themselves can be explained in terms of a change in the relative coordination number of DMSO and water molecules, from 1DMSO:2H2O to 1H2O:1DMSO and 1H2O:2DMSO complex formation. Thus, while the emergence of first slow down (at 15% DMSO mole percentage) is due to the percolation among DMSO molecules supported by the water molecules (whose percolating network remains largely unaffected), the 2nd anomaly (centered on 40%-50%) is due to the formation of the network structure where the unit of 1DMSO:1H2O and 2DMSO:1H2O dominates to give rise to rich dynamical features. Through an analysis of partial solvation dynamics an interesting negative cross-correlation between water and DMSO is observed that makes an important contribution to relaxation at intermediate to longer times.

Thermodynamic Investigation of Dimethyl Sulfoxide Binary Mixtures at 293.15 and 313.15 K

Densities (ρ), speeds of sound (u), and isentropic compressibilities (kS) of binary mixtures of dimethyl sulfoxide (DMSO) with water, methanol, ethanol, 1-propanol, 2-propanol, acetone and cyclohexanone have been measured over the entire composition range at 293.15 and 313.15 K. The excess molar volumes (VE), the deviations in speed of sound (uE) and the deviations in isentropic compressibility (kSE) have been determined. The VE, uE and kSE values were fitted by the Redlich-Kister polynomial equation and the Ak coefficients as well as the standard deviations (d) between the calculated and experimental values have been derived. The results obtained are discussed from the viewpoint of the existence of interactions between the components of the binary mixtures.

Effects of medium on decarboxylation kinetics: 3-carboxybenzisoxazoles and their potential use as environmental probes in biochemistry.

The decarboxylation rate of the tetramethylguanidinium salt of 3-carboxy-6-nitrobenzisoxazole in 24 pure solvents and 36 dimethyl sulfoxide binary mixtures with diglyme, acetonitrile, benzene, dichloromethane, chloroform, and methanol was analyzed in the light of the SPP, SA, and SB pure solvent scales. The results allow one to rationalize the high sensitivity of this kinetics to the reaction medium and to assess the potential use of this compound as a probe in biochemical environments. The natural environment for comparison of this kinetics was found to be the gas phase rather than the aqueous medium. In the latter, the process is much faster owing to such high polarity, which, however, is strongly diminished by the high acidity of the medium. Based on our calculations, the rate constant for the decarboxylation kinetics in the gas phase must be in the region of 2 x 10(-10) s(-1) (i.e., 3 orders of magnitude smaller than in water).