Surface tensions along the homologues series of alpha,omega-dibromo- and dichloroalkanes in the temperature range 293.15-313.15 K have been measured by the pendant drop method. The new atmospheric pressure density data for some of these compounds have been reported as well. Based on the current experimental surface tension data, the surface entropy and surface enthalpy have been determined. It has also been demonstrated that SAFT-VR-Mie attached by a predictive corresponding states correlation based on the description of fluid phase properties by means of Mie intermolecular potential accurately estimates some of the reported surface tension data and correctly describes their trends. (C) 2018 Elsevier Ltd.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

A series of new ionic liquids of the formula Ax[CoII(NCO)4] with the [CoII(NCO)4]2– anion and nitrogen‐based organic cations (A) were synthesized. The single‐crystal structures of all of the compounds were determined by X‐ray diffraction, and the presence of discrete ions was revealed for all cases. At room temperature, these compounds exhibit paramagnetic behavior owing to the presence of high‐spin tetrahedrally coordinated CoII ions. The melting points or glass‐transition temperatures are in the range for ionic liquids for some of the compounds with singly charged cations and above 100 °C for all compounds with doubly charged cations and the bis(triphenylphosphine)iminium ([PPN]+) salt. Each compound was characterized by elemental analysis as well as NMR, IR, and UV/Vis spectroscopy. Measurements of the density, dynamic viscosity, conductivity, and surface tension of the low‐melting substance [EMIm]2[Co(NCO)4] ([EMIm]+ = 1‐ethyl‐3‐methylimidazolium) show that they differ slightly to the corresponding values for the isothiocyanato complexes but are generally comparable.

Partial molar excess enthalpies of mixing of the organic liquids methanol, acetonitrile, acetone and propan-1-ol in 1-ethyl-3-methylimidazolium ethyl sulfate ([EMIM][EtSO4]) have been measured using a titration calorimeter. Data have been obtained at 298K, in the case of methanol also at 308K, in the mole fraction range of the organic liquid x2 from 0.005 to 0.05. The results have been extrapolated to infinite dilution for determining enthalpies of dilution at infinite concentrations H¯2,∞E (x2=0). Alternatively values of H¯2,∞E can be obtained from measurements of activity coefficients γ2∞ at different temperatures using the gas chromatographic or the dilutor technique. However, according to our error analysis calorimetric results of H¯2E,∞ are by a factor 2–3 more reliable than the results obtained by the indirect methods.

Two new analytical methods using UV-spectroscopy and densimetry have been applied for measuring LLE of the following systems at lower temperatures in the region of restricted mutual solubilities: [CnMIM][NTf2] (n = 2,4,6), + n-butanol, + n-pentanol, + water. The data obtained agree very well with results obtained at higher temperatures for the same systems using the synthetic laser scattering method.

The surface tension, sigma, of binary mixtures of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [BMIm][NTf2] with tetrahydrofuran (oxolane, thf), acetonitrile, dimethylsulfoxide ((methylsufinyl)methane, dmso) and of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide [EMIm][NTf2] with dimethylsufoxide was measured between (293.15 and 313.15) K using the pendant drop method. On the basis of experimental sigma values and activity coefficients of solutes in their solutions with ionic liquid obtained from vapor pressure measurement, Gibbs excess surface concentrations of thf, acetonitrile or dmso in mixtures with [BMIm][NTf2] or [EMIm][NTf2] were determined. The results are discussed in terms of possible interactions between ILs and aprotic polar substances. (c) 2013 Elsevier Ltd. All rights reserved.

The physicochemical characteristics of two homologous room temperature ionic liquids (RTIL, IL) 1-methyl-1-propylpyrrolidinium bis[(trifluoromethyl) sulfonyl] imide [MPPyr][NTf2] and 1-butyl-1-methylpyrrolidinium bis[(trifluoromethyl) sulfonyl] imide [BMPyr][NTf2] are presented. Based on density, speed of sound, viscosity and surface tension measured in the temperature range of (288.15 to 323.15) K some related parameters, like isobaric coefficient of thermal expansion, isentropic compressibility coefficient, parameters of Vogel-Fulcher-Tamman (VFT) equation, surface entropy and enthalpy were calculated. These results were compared with those of some homologs from the 1-alkyl-3-methyl imidazolium bis[(trifluoromethyl) sulfonyl] imide [C(n)MIm][NTf2] family in order to systematize the knowledge about investigated substances. In the next part volumetric and surface properties, like excess molar volumes and Gibbs surface excess of methanol or acetonitrile in binary systems with [BMPyr][NTf2] were determined at three temperatures (288.15, 298.15 and 308.15) K. The results of these studies indicate that the volumetric quantities of binary mixtures and the surface properties obtained with same solvents in two different classes of ionic liquids pyrrolidinium bis[(trifluoromethyl) sulfonyl] imides and imidazolium bis[(trifluoromethyl) sulfonyl] imides are very similar. (C) 2013 Elsevier Ltd. All rights reserved.

The liquid-liquid equilibria of two binary systems containing 1-butyl-1-methylpyrrolidinium bis-(trifluoromethylsulfonyl)imide with butan-1-ol or hexan-1-ol at atmospheric pressure have been investigated. The two-phase line was observed as function of temperature using light scattering or visual detection. In addition, other physical properties such as the densities of phases in equilibrium and the interfacial tension were determined. The results obtained were compared with the literature and briefly discussed in terms of possible interactions that may occur in ionic liquid + alkan-1-ol solutions.

The surface tensions of binary mixtures containing the ionic liquid 1-ethyl-3-methyl-imidazolium bis[(trifluoromethyl)sulfonyl]imide ([EMIM][NTf2]) and the aprotic solvents tetrahydrofuran (THF) or acetonitrile were measured at temperatures in the range from (293.15 to 313.15) K (or to 308.15 K for the system with THF) using the pendant drop method. On the basis of these experimental results and activity coefficients taken from vapor pressure measurements, the Gibbs excess surface concentrations for mixtures were calculated. The results and their relationship to electrolyte solutions are discussed.

The interaction of natural α-, β-, and γ-cyclodextrins (CDs) with 14 hydrophobic ionic moieties of ionic liquids (ILs) was systematically examined in dilute aqueous solutions using isothermal titration microcalorimetry (ITC) and NMR spectroscopy. The studied cationic and anionic moieties involved some recently developed heavily fluorinated structures, as well as some others of common use. To isolate the effect of a given ion, the measurements were performed on salts containing the hydrophobic IL ion in question and a complexation-inactive counterion. Additional ITC experiments on ILs whose both cation and anion can interact appreciably with the CD cavity demonstrated that to resolve the effect of individual ions from such data is generally a tricky task and confirmed the superiority of the isolation strategy adopted for the purpose throughout this work. The binding constant, enthalpy and entropy determined at 298.15 K for the 1:1 (ion:CD) inclusion complex formation range in broad limits, being 0 < K < 2 × 10(5), 0 < -Δ(r)H°/(kJ·mol(-1)) < 44, and -28 < TΔ(r)S°/(kJ·mol(-1)) < 14, respectively. The stabilities of complexes of perfluorohexyl bearing ions with β-CD belong to the highest ever observed with natural CDs in water. The established binding affinity scales were discussed in both thermodynamic and molecular terms. The concepts of hydrophobic interaction and guest-host size matching supported by simple molecular modeling proved useful to rationalize the observed widely different binding affinities and suggest possible binding modes. Enthalpy and entropy contributions to the stability of the ion-CD complexes were found to compensate each other considerably obeying more or less the linear compensation relationship marked by existing literature data on binding other guests to natural CDs. As outliers to this pattern, the most stable complexes of -C(6)F(13) bearing ions with β-CD were found to receive an enhanced inherent entropy stabilization due to extraordinarily high extent of desolvation occurring in the course of binding.

This paper describes selected thermophysical properties of the newly obtained paramagnetic inky, opaque ionic liquid, 1-butyl-3-methylimidazolium tetraisothiocyanato-cobaltate(II) ((BMIm)(2)[Co(NCS)(4)]). Some properties of the homologous ionic liquid (IL), 1-ethy1-3-methylimidazolium tetraisothiocyanato-cobaltate(II) ((EMIm)(2)[Co(NCS)(4)]), have been presented earlier and are discussed here together with those for (BMIm)(2)[(Co(NCS)(4)]. On the basis of experimental densities, kinematic viscosities, conductivities, and surface tensions, some additional parameters have been determined, i.e., expansivity coefficients and surface thermodynamic properties. The influence of structural variation in the 1-alkyl-3-methylimidazolium cation is also discussed.

Magic ink: Ionic liquids that consist of paramagnetic [Co(NCS)4]2− anions and imidazolium-based cations have glass-transition temperatures below −60 °C. The ink-like liquids also have unexpected low viscosities, ion conductivities, and low heats of vaporization, along with high hydrolytic stability and insensitivity to air.

Cobalt im Tintenfass: Ionische Flüssigkeiten, die aus paramagnetischen [Co(NCS)4]2−-Ionen und Imidazolium-basierten Kationen aufgebaut sind, haben trotz ihrer zweifach negativ geladenen Anionen Glasübergangstemperaturen unter −60 °C. Die tintenähnlichen Flüssigkeiten zeigen unerwartet niedrige Viskositäten und Verdampfungsenthalpien sowie gute Hydrolyse- und Oxidationsbeständigkeit. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Using isothermal titration calorimetry heats of dilution of the aqueous ionic liquid solutions [C4MIM][C8SO4], [C12MIM]Cl, [C16MIM][BF4], and [C16MIM]Cl have been measured in the concentration range of (1–80, 1–35, 0.2–2.2, and 0.1–2.6)mmoldm−3 respectively at different temperatures between 283K and 338K. Formation of micelles has been observed. The CMC, the equilibrium constant of micellization as well as the enthalpy of micellization has been determined from the experimental data using a mass-action model with 3–5 parameters adjusted to the experimental data points of the heat of dilution over the whole concentration range. Three modified versions of the model have been tested providing similar results with exception of [C16MIM][BF4] solutions where one of the versions failed. The consistency of the model has been tested by comparing the model parameters of our own experimental results of Na[C12SO4] solutions with those obtained from experimental data of other authors in the literature. Our evaluation process shows that the CMC decreases in the order of [C4MIM][C8SO4], [C12MIM]Cl, [C16MIM]Cl and [C16MIM][BF4]. The enthalpy of micellization changes its sign with temperature in all cases studied in aqueous solutions. It is positive at lower temperatures and becomes negative at higher temperatures. Also solutions of [C16MIM][BF4] and [C16MIM]Cl in ethylammonium nitrate (EAN) have been studied in the same way. In contrast to the aqueous solutions the enthalpy of micellization is always negative without significant dependence on temperature.

Densities of six binary mixtures containing the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide or 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide mixed with tetrahydrofuran or acetonitrile or dimethyl sulfoxide were determined at atmospheric pressures in the temperature range between 293.15 K and 313.15 K. On the basis of the experimental densities, excess molar volumes were calculated. Comparison of excess molar volumes of six binary systems reveals the slight influence of the IL's cation on these physical properties and the small temperature dependence of VE for systems containing dimethyl sulfoxide.

The pendant drop method has been used for measuring the surface tension of the pure ionic liquids 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, butyltrimethylammonium bis(trifluoromethylsulfonyl)imide, methyltrioctylammonium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium ethylsulfate, and 1-butyl-3-methylimidazolium octylsulfate in the range of (278 to 333) K. In addition, densities and thermal expansion coefficients of these ionic liquids are presented. The values of surface tension lie between (25 and 48) mN . m(-1) and decrease with temperature. Surface tension a of the mixtures of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide + 1-propanol and + 1-butanol have also been determined as a function of the mole fraction at 298 K. Since the pendant drop method requires precise density measurements of the mixtures, densities were also measured.

Activity coefficients at infinite dilution γi∞ of methanol, 1-butanol, and 1-hexanol in the ionic liquid 1-hexyl-3-methyl-imidazolium bis(trifluoromethyl-sulfonyl) imide ([HMIM][NTf2]) have been determined by gas chromatography using the ionic liquids as stationary phase. The measurements were carried out at different temperatures between 298K and 396K. From the temperature dependence of the limiting activity coefficients partial molar excess enthalpies at infinite dilution HiE,∞ of the alcohol in the ionic liquid have been derived. Additionally, enthalpies of solution of the same alcohols in the [HMIM][NTf2] have been measured at T=298.15K in the range of low concentrations using titration calorimetry. Results at infinite dilution, HiE,∞, are compared with those indirectly obtained from activity coefficients in infinite dilution γi∞. Within the experimental error of both methods thermodynamic consistency has been confirmed.

Viscometry is an often applied method in clinical chemistry. A variety of studies demonstrate an association of parameters related to blood viscosity with human pathology of varying origin. Whole blood and plasma viscosity are considered to be clinically useful indicators in the diagnostic workup and therapy monitoring of certain diseases. In this study, we compare the "Waegeviskosimeter" (WV) described in previous publications with a newly developed device, the "Reverse Flow Viscometer" (RFV). Both viscometers are capillary flow viscometers. Both overcome the disadvantage of common viscometers of the Ubbelohde and Cannon-Fenske type which require large amounts of plasma and which can be only applied to Newtonian fluids. The accuracy of the measurements of both viscometers, requiring less than 1.0 ml sample volume, is superior to most conventional methods. The major distinction in the functionality of the WV and the RFV is that the WV measures the kinematic viscosity whereas the RFV directly estimates dynamic viscosity without the requirement of additional density measurement. We found good reproducibility of viscosity with coefficient of variation CV < or =1.1% for both viscometers. Quality assurance measures have been carried out. Because no quality assurance scheme according to the guidelines proposed by the German Medical Association exists for plasma or whole blood viscosity, we tested reference material Lyphochek Unassayed Chemistry Control Level 1 and Level 2 (Bio-Rad Laboratories). We determined the viscosities 1.40 mPa s and 1.08 mPa s (37 degrees C) and the between-run precision from daily quality control runs with CV of 1.4% and 1.2% for the WV, and 1.7% and 1.4% for the RFV. For direct comparison reasons, we determined the viscosity in seventy human plasma and serum samples by both methods. Using the regression analysis described by Passing-Bablok, the RFV and the WV methods are highly correlated and show only little variations (r = 0.990, tau = 0.896). The regression equation is y(WV) = 1.035x(RFV) - 0.056 with a mean deviation of 0.4+/-3.6%. We conclude that both new devices for viscosity assessment fulfill all quality requirements as prescribed for clinical chemical laboratories. One advantage RFV is to measure the dynamic viscosity directly.

Experimental densities were measured for the system 1-methyl-3-octyl-imidazolium tetrafluoroborate [OMIM][BF4] + butan-1-ol, + pentan-1-ol at 298.15 K and ambient pressure using a vibrating tube densimeter, taking into account the influence of the viscosity correction. Excess molar volumes VE have been determined. VE is quite small and negative in the alcohol-rich range of the mixture composition and positive in the alcohol-poor range. LLE data of [OMIM][BF4] + pentan-1-ol have been measured using a laser light scattering cell for detecting cloud points at different compositions in the temperature range of 282–292 K. A miscibility gap with an upper critical solution temperature (UCST) of 292 K has been found.