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In the present study, measurements of experimental density (ρ), viscosity (η) and speed of sound (u) of binary liquid mixtures of 2-methyl-1-butanol with ethylene glycol monomethyl ether, diethylene glycol monomethyl ether and triethylene glycol monomethyl ether have been carried out within the temperature range of 298.15–308.15 K with an interval of 5 K. Using the experimental data, excess properties such as excess molar volume ( V m E ), excess molar isentropic compressibility ( K s , m E ), excess speed of sound ( u E ), deviation in viscosity (Δη) and excess Gibbs free energy of activation for viscous flow ( Δ G * E ) have been calculated to study the intermolecular interactions present in these liquid mixtures. By comparing the standard deviation values the correlation ability of various proposed viscosity models has also been tested. Further, to rationalize the excess volume data Prigogine–Flory–Patterson (PFP) theory has also been studied. [ABSTRACT FROM AUTHOR]

In the present study, intermolecular interactions for binary liquid mixtures of 1-propoxy-2-propanol with amines namely diisopropylamine, dibutylamine and tributylamine have been examined through experimentally measured values of density (ρ ), speed of sound (u) and viscosity (η ). Measurements were carried out over entire the composition range and temperature range from 298.15 to 308.15 K. Various excess and deviation parameters have been calculated using measured data. These excess and deviation properties have been discussed in terms of intermolecular interactions in the mixtures. The presence of strong intermolecular interactions among unlike molecules in binary mixtures of 1-propoxy-2-propanol with diisopropylamine and dibutylamine while weak interactions in case of tributylamine have been revealed by these properties. Excess and deviation properties have been correlated with composition using Redlich–Kister polynomial. The Jouyban–Acree model was used to correlate the measured data with composition. Further, studies on Fourier-transform infrared spectroscopy were also carried out at room temperature. [ABSTRACT FROM AUTHOR]

Binary liquid mixtures of 1-butoxy-2-propanol with amines namely diethylamine, dipropylamine and triethylamine have been discussed in the present discussion. Measurements of density and speed of sound of pure liquids and their binary mixtures have been carried out over the entire composition range and temperatures (298.15, 303.15 and 308.15) K. To study the thermodynamic behaviour of these liquid mixtures, various parameters were calculated using the experimentally measured data. Strong intermolecular interactions among the components of binary liquid mixtures were confirmed by calculated parameters. Various excess and deviation properties were correlated to composition using the Redlich–Kister polynomial. Further, density and speed of sound data were correlated with composition using Jouyban–Acree model. The experimental results have been analysed by using Prigogine–Flory–Patterson (PFP) theory. 1H-NMR spectra of binary mixtures at equimolar composition has also been studied. [ABSTRACT FROM AUTHOR]

Experimental thermodynamic and spectroscopic investigations on binary liquid mixtures containing tri-n-butylamine with 2-propanol, 2-butanol and 2-pentanol have been discussed in this article. The aforesaid binary mixtures have been examined over the entire range of composition at a temperature range of 293.15–308.15 K with a temperature step of 5 K and at 0.1 MPa pressure. To explore the mixtures thermodynamically, the density ( ρ) and speed of sound (u) at various compositions and temperatures have been measured. Experimental values of these two properties have been used to find out various thermodynamic parameters, viz., excess molar volumes ( V m E ), excess isentropic compressibilities ( κ s E ), apparent molar volumes ( V φ ), partial molar volumes ( V ˉ m ), excess partial molar volumes ( V ˉ m E ) and partial molar volumes at infinite dilution ( V ˉ m E , ∞ ). These parameters are analysed in terms of form and degree of unlike interactions. Along with this, these parameters are also examined to figure out the effect of chain length and temperature on interactions. Further, the computed excess parameters have also been correlated with the compositions using the Redlich–Kister-type polynomial. Similar to excess parameters, the density and speed of sound have also been correlated to compositions using the Jouyban–Acree model. Apart from this, the mixtures were also analysed using FTIR spectroscopy studies. [ABSTRACT FROM AUTHOR]

In the present discussion, thermodynamic and spectral behaviour of binary mixtures of 1-tert-butoxy-2-propanol with amines namely dipropylamine, diethylamine and triethylamine have been studied. To achieve the objectives, density (ρ ) and speed of sound (u) of selected liquids and their binary mixtures were measured over entire composition range and different temperatures (298.15, 303.15 and 308.15) K. Using the experimentally measured data, various excess properties were computed. Variation of these properties with composition has been discussed in terms of intermolecular interactions. Presence of strong intermolecular interactions has been confirmed by these excess and deviation properties. Magnitude of these parameters reflects the order of interaction among these liquid mixtures. Using the Redlich–Kister polynomial equation, these excess properties were correlated with composition. Further, density and speed of sound values of these binary mixtures were correlated with composition using Jouyban-Acree model. FT-IR spectra of these liquid mixtures have also been recorded. Spectral analysis of these mixtures also confirms the presence of strong intermolecular interactions in studied liquid mixtures. [ABSTRACT FROM AUTHOR]

Experimental values of density (ρ ), speed of sound (u) and viscosity (η ) of binary mixtures of 2-isopropoxy ethanol with dipropylamine, diethylamine and triethylamine at temperatures (298.15, 303.15 and 308.15) K are reported. Various excess and deviation properties were calculated using these experimentally measured values. A stronger solute–solvent interaction compared to solute–solute or solvent–solvent interactions, due to formation of hydrogen bonding is confirmed by the trends of these parameters. The excess and deviation properties were correlated with composition using Redlich–Kister polynomial. Density, speed of sound and viscosity data were correlated to composition using Jouyban–Acree model. Further, change in enthalpy ( Δ H ∗ ) and change in entropy ( Δ S ∗ ) of viscous flow were calculated using the viscosity data. Various semi-empirical models of viscosity were tested. The correlation ability of tested models increases with increase in the number of adjustable parameters. FT-IR spectra of these mixtures also support the results obtained from calculated parameters. [ABSTRACT FROM AUTHOR]

In recent times, fused azaheterocycles emerged as impressive therapeutic agents. Binding studies of such azaheterocycles with biomolecules is an important subject for pharmaceutical and biochemical studies aiming at the design and development of new drugs. Fused heterocyclic scaffolds, such as thiazolopyrmidines have long been used in the pharmaceutical industry for the treatment of various diseases. In this study, we have accomplished a regioselective synthesis of 2-aroyl-3-methyl-6,7-dihydro-5H-thiazolo[3,2-a]pyrimidines by the reaction of tetrahydropyrimidine-2(H)-thione with α-bromo-1,3-diketones, generated in situ from 1,3-diketones and NBS, using visible light as an inexpensive, green and renewable energy source under mild reaction conditions with wide-ranging substrate scope. The regioisomer was characterized unambiguously by 2D-NMR [1H-13C] HMBC and [1H-13C] HMQC spectroscopy. In silico toxicity data analysis showed the low toxicity risks of the synthesized compounds. Computational molecular docking studies were carried out to examine the interaction of thiazolo[3,2-a]pyrimidines with calf-thymus DNA (ct-DNA) and Bovine Serum Albumin (BSA). Moreover, different spectroscopic approaches viz. steady-state fluorescence, competitive displacement assay, UV–visible and circular dichroism (CD) along with viscosity measurements were employed to investigate the binding mechanisms of thiazolo[3,2-a]pyrimidines with DNA and BSA. The results thus obtained revealed that thiazolo[3,2-a]pyrimidines offer groove bindings with DNA and showed moderate bindings with BSA. [ABSTRACT FROM AUTHOR]

In continuation to our previous publication, non-ideal behavior of 2-(2-butoxyethoxy) ethanol with amines namely dipropylamine, diethylamine and triethylamine has been discussed in present communication. Herein, the values of excess molar volume ( V m E ) calculated using Prigogine–Flory–Patterson theory have been compared with the experimental values. Using the density and speed of sound data, excess acoustic impedance ( Z E ) and excess intermolecular free length ( L f E ) have been computed. Various semi-empirical purposed relations of viscosity have also been tested. Their correlation ability has been compared using standard deviation values. Change in the enthalpy ( Δ H ) and change in the entropy ( Δ S ) of activation of viscous flow have been calculated to study to thermodynamic of viscous flow. Jouyban–Acree model was used to correlate density, speed of sound and viscosity with composition. 1H NMR spectra of binary liquid mixtures have also been studied at equimolar composition and interpretation in terms of chemical shift (δ ) has been discussed. [ABSTRACT FROM AUTHOR]

Densities and speeds of sound for the binary liquid mixtures of tri-n-butylamine with three solvents, namely 1-propanol, 1-butanol and 1-pentanol are measured. The measurements were done over the entire composition range at temperatures from 293.15 to 308.15 K with an interval of 5 K and at atmospheric pressure. Experimental data were used to calculate various thermodynamic parameters like excess molar volumes ( V m E ), excess isentropic compressibilities ( κ s E ), deviations in speed of sound ( u D ), apparent molar volumes ( V φ ), partial molar volumes ( V ˉ m ) and excess partial molar volumes ( V ˉ m E ). Intermolecular interactions present in these mixtures were studied with the help of the calculated data. Studies on Fourier-transform infrared spectroscopy were also done to support the conclusions. Redlich–Kister type polynomial was used to correlate the various excess and deviation parameters to the compositions. Further, the Jouyban–Acree model was used to correlate densities and speeds of sound data with the compositions. [ABSTRACT FROM AUTHOR]

Non-ideal behaviours of binary mixtures of 2-butoxy ethanol with 1-hexanol, 1-octanol and 1-decanol have been analysed at different temperatures and over the whole composition range. For this purpose, experimental densities were used to estimate apparent molar volumes, partial molar volumes, excess partial molar volumes. and their limiting values at infinite dilution,andrespectively. Experimental viscosities were used to calculate the deviations in viscosity, ∆η.The calculated properties were interpreted in terms of molecular interactions and structural effects. A volumetric result has been analysed in the light of Prigogine–Flory–Patterson (PFP) statistical mechanical theory. Interaction parameters have been calculated fromvalues for all the studied systems. The solute–solvent interactions have been investigated in terms of each of the three contributions, viz. interactional, free volume and P*obtained from PFP theory at equimolar concentration. The results ofcalculated from PFP theory are compared with thereported in our earlier communication. [ABSTRACT FROM PUBLISHER]