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In present communication, we report the experimental values of density (ρ), viscosity (η), and speed of sound (u) of binary mixtures of 4-methyl-2-pentanol with 2-ethoxyethanol, 2-propoxyethanol, and 2-butoxyethanol at T= (298.15, 303.15, and 308.15) K. The excess and deviation properties, such as excess molar volume (VmE), excess molar isentropic compressibility (Ks,mE), excess speed of sound (uE), deviation in viscosity (Δη), and excess Gibbs energy of activation for viscous flow (ΔG*E) were evaluated using the experimentally measured values of density (ρ), viscosity (η), and speed of sound (u). The variations in these properties with composition and temperature were used to study the interactions due to physical and chemical effects between the unlike components of the binary mixtures. Further, density values were used to estimate partial molar volumes (V¯m,i), excess partial molar volumes (V¯m,iE), and their limiting values at infinite dilution (V¯m,iE,∞). The excess properties were fitted to the Redlich–Kister polynomial equation. The correlation ability of various semiempirical relations of viscosity was also compared using standard deviation. The excess volume data have also been rationalized by the Prigogine–Flory–Patterson theory. Fourier transform infrared spectra of these liquid mixtures were also recorded. Spectral analysis of these mixtures also supports the results obtained from calculated parameters.

Densities, speeds of sound, and viscosity values have been experimentally measured at temperature ranges from (298.15 to 308.15 K) and a pressure of 0.1 MPa for the whole compositions for the binary mixtures of tetrahydrofuran with methyl acetate, propyl acetate, and pentyl acetate. Excess molar volume (VmE), excess molar isentropic compressibility (ΔKS,mE), viscosity deviation (Δη), excess Gibb’s free energy of activation for viscous flow (ΔG*E), and partial molar volume (V̅m,i) have been derived with the help of experimental results and fitted to an extended Redlich–Kister equation by the least-squares approach that simultaneously considers the dependency on composition and temperature. For the calculated and experimental data, the standard deviations are estimated. The magnitude and sign of these excess properties have been utilized to explain the results in terms of structural and intermolecular interactions. Various semiempirical viscosity relations were tested using the data of viscosity of binary mixtures.

In fuel reformulation, the thermodynamic properties of oxygenated compounds, such as ethers and alcohols, play a significant role. The excess thermodynamic properties reveal the various interactions taking place in the mixtures of oxygenates. So, here we determine the density (ρ), viscosity (η), and speeds of sound (u) of four liquids and binary combinations of 2-methyl-2-butanol with ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, and triethylene glycol monomethyl ether at temperatures of (298.15, 303.15, and 308.15) K. The experimental results were used to evaluate the excess properties such as excess molar volume (VmE), excess molar isentropic compressibility (Ks,mE), excess speed of sound (uE), deviation in viscosity (Δη), and excess Gibbs free energy of activation for viscous flow (ΔG*E). The variations in these properties with composition and temperature were used to study the interactions taking place in these binary liquid mixtures. The excess properties were fitted to the Redlich–Kister polynomial equation. The correlation ability of various proposed viscosity semiempirical relations was also compared using standard deviation. The excess volume data have also been rationalized by the Prigogine-Flory-Patterson (PFP) theory. The calculated values of VmEobtained from the PFP theory agree with the corresponding experimental results.

In the present paper, binary mixtures of 1-butoxy-2-propanol with diisopropylamine, di-n-butylamine, and tri-n-butylamine were studied. To achieve that goal, the density (ρ), speed of sound (u), and viscosity (η) of the binary mixtures were measured over the entire composition range and temperature range from 298.15 to 308.15 K. With the help of experimentally measured data, various excess and deviation thermodynamic parameters were calculated and discussed in terms of intermolecular interactions among studied mixtures. Strong interactions among unlike molecules were confirmed by calculated parameters. Excess and deviation parameters were correlated with composition using the Redlich–Kister equation. Various semi-empirical relations for viscosity were also tested for the binary liquid mixtures.

The speed of sound (u), density (ρ), and viscosity (η) of binary mixtures including tetrahydrofuran (THF) and acetates, namely, butyl acetate (BA), tert-butyl acetate (TBA), and isobutyl acetate (IBA), were studied over the whole range of composition at temperatures of 298.15, 303.15, and 308.15 K. Thermodynamic parameters such as excess molar volume (VmE), excess molar isentropic compressibility (ΔKS,mE), viscosity deviation (Δη), excess Gibbs free energy of activation for viscous flow (ΔG*E), and partial molar volume (V̅m,i) have been calculated using the experimental data. The excess/deviation parameters were plotted against the mole fraction of THF. The measured negative and positive values of excess/deviation parameters were helpful for explaining the interactions in molecules of binary mixtures. The magnitude of these factors verifies the order of interaction of tetrahydrofuran with acetates. For the estimation of standard deviations and binary coefficients, excess and deviation parameters were correlated using a Redlich–Kister type polynomial equation. Further, to assess the correlation ability of various models for viscosity, standard deviations were also determined.

The nature of interaction of binary liquid mixtures of 2-butoxy ethanol with amines, namely, diisopropylamine, dibutylamine, and tributylamine, has been examined using the experimentally measured values of density (ρ), ultrasonic speed (u), and viscosity (η) over the temperature range from 298.15 to 308.15 K, in the present discussion. Using the experimentally measured values, various excess and deviation properties have been evaluated and discussed in terms of interaction among the studied binary mixtures. Strong intermolecular interaction among unlike components of binary mixtures is confirmed by these calculated properties. The order of the magnitude of these properties gives an insight into the order of interaction of mixtures of 2-butoxy ethanol with amines. Excess and deviation properties have been correlated with composition using the Redlich–Kister polynomial. The correlation ability of various viscosity models has also been compared. The Fourier transform infrared spectra of these liquid mixtures have also been studied at room temperature.

Organic transformations mediated by visible light have gained popularity in recent years as they are green, renewable, inexpensive, and clean and yield excellent products. The present study describes cyclo-condensation of 2-methylthiazole-4-carbothioamide with differently substituted α-bromo-1,3-diketones achieved by utilizing a white light-emitting diode (LED) (9W) to accomplish the regioselective synthesis of novel 5-aroyl/hetaroyl-2′,4-dimethyl-2,4′-bithiazole derivatives as DNA/bovine serum albumin (BSA)-targeting agents. The structure characterization of the exact regioisomer was achieved unequivocally by heteronuclear two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy [1H–13C] HMBC; [1H–13C] HMQC; and [1H–15N] HMBC. In silico toxicity studies indicated that the synthesized compounds exhibit low toxicity risks and adhere to the rules of oral bioavailability without any exception. Computational molecular modeling of the bithiazole derivatives with the dodecamer sequence of the DNA duplex and BSA identified 5-(4-chlorobenzoyl)-2′,4-dimethyl-2,4′-bithiazole 7gas the most suitable derivative that can interact effectively with these biomolecules. Furthermore, theoretical results concurred with the ex vivo binding mode of the 7gwith calf thymus DNA (ct-DNA) and BSA through a variety of spectroscopic techniques, viz., ultraviolet–visible (UV–visible), circular dichroism (CD), steady-state fluorescence, and competitive displacement assay, along with viscosity measurements.

Fused heterocyclic systems containing a bridgehead nitrogen atom have emerged as imperative pharmacophores in the design and development of new drugs. Among these heterocyclic moieties, the imidazothiazole scaffold has long been used in medicinal chemistry for the treatment of various diseases. In this study, we have established a simplistic and environmentally safe regioselective protocol for the synthesis of 5,6-dihydroimidazo[2,1-b]thiazole derivatives from easily available reactants. The reaction proceeds through in situformation of the α-bromodiketones ensuing trap with imidazolidine-2-thione to provide these versatile bicyclic heterocycles in excellent yields. The synthesized compounds were screened through the molecular docking approach for the most stable complex formation with bovine serum albumin (BSA) and calf thymus deoxyribonucleic acid (ctDNA). The selected compound was further studied using ex vivobinding studies, which revealed moderate interactions with BSA and ctDNA. The binding studies were performed using biophysical approaches including UV–visible spectroscopy, steady-state fluorescence, circular dichroism (CD), and viscosity parameters.

The ultrasonic velocities of binary liquid mixtures of 1,1,2,2-tetrachloroethane with benzene, toluene,p-xylene, acetone and cyclohexane have been evaluated at 298.15 and 308.15 K using Schaaff’s collision factor theory (CFT), Jacobson’s free length theory (FLT), Nomoto’s relation and Van Dael ideal mixing relation. The ideal mixing relation gives the minimum deviation for all the systems except with acetone. The intermolecular free length has also been evaluated using ultrasonic and thermodynamic methods and the limitations of both the methods have been discussed. The deviations in ultrasonic velocity and intermolecular free length are discussed in terms of weak interaction between unlike molecules.