A new fluorescent compound of p-[N,N-bis(2-chloroethyl) amino] benzaldehyde substituted with acetone (1) and acetylacetone (2) derivatives were synthesised by Claisen-Schmidt condensation reaction and their structures were characterised by spectroscopic and DFT techniques. The photophysical studies were examined in a DMSO medium for both, shows bright yellow emission. The solvatochromic behavior of compounds 1 and 2 was studied using optical and fluorescence spectroscopy in various solvents. DFT studies were performed to validate the photophysical characteristics of these compounds. Aggregation studies of compounds 1 and 2 in DMSO:H2O showed shifts in fluorescence and absorbance, indicating ACQ. The antioxidant activity of compounds 1 and 2 was also examined using the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging assay, in which compound 1 shows antioxidant activity reaching 75-78% inhibition at 50 & micro;M due to an effective conjugated system and in contrast compound 2 due to disturbed conjugation acts as powerful oxidant.
Time domain reflectometry (TDR) technique has been used to determine the complex permittivity, static dielectric constant (epsilon 0) and relaxation time for toluene + dimethylsuphoxide (DMSO) mixtures in the frequency range of 10 MHz to 50 GHz. Molecular interactions among toluene + DMSO mixtures have been explored utilising dielectric parameters. Alenka Luzar's hydrogen-bonded theory is used to establish theoretical estimates of the epsilon 0 that closely match the results of experiments. The findings of the present study focus on the intricate relationship between different components in binary mixtures of toluene + DMSO and their effect on dielectric properties, providing valuable insights for a wide range of applications.
Densities of dilute solutions of acetanilide, acetaminophen and phenacetin were measured as a function of molal drug concentration in some {ethanol (1) + water (2)} mixtures and neat ethanol (1) at T/K = 298.15 and T/K = 313.15. From these density values, apparent molar volumes, limiting apparent molar volumes and S V parameters of drug concentration-dependence of apparent molar volumes, limiting molar transfer properties, and limiting molar volumes of some substituent groups, were calculated and the results were interpreted in terms of structural effects, and possible solute-solvent interactions.
Experiment-based Abraham model solute descriptors have been determined for oxibendazole, 3,3'-diindolylmethane, meglumine, N-acetyl-L-phenylalanine and tranilast based on recently published mole fraction solubility data. The calculated descriptor values, when inserted into the respective Abraham model correlation, provided a reasonably accurate mathematical description of the observed solubility behaviour, with deviations between the measured and back-calculated values being on the order of +/- 0.17 log units (or less).
This research presents a comprehensive investigation upon thermophysical and physicochemical properties of binary liquid mixtures of 3-dimethylamino-1-propylamine (DMAPA) and three para-substituted propiophenones (4-methylpropiophenone, 4-methoxypropiophe-none and 4-chloropropiophenone). Measurements of density, viscosity and ultrasonic speed were conducted across the entire composition range at various temperatures under atmospheric pressure. The results show negative values for V E and kappa s E, and positive values for triangle eta and triangle G *E, suggesting strong intermolecular interactions between the amino groups of DMAPA and the carbonyl groups of ketones. Partial molar properties and molar volumes were derived to elucidate solute-solvent environment and packing efficiency within mixtures. The influence of para-substituents on the magnitude of these interactions showed distinct electronic effects on the mixture's volumetric behaviour. Experimental findings were validated using Jouyban-Acree model, which demonstrated excellent agreement with low deviations. These findings provide critical thermodynamic insights into structural effects of substituted aromatic ketones in amine-based systems, offering valuable data for applications involving chemical processing and solvent design.
The Bretonnet–Silbert (BS) pseudopotential with linearised Weeks–Chandler–Andersen (LWCA) perturbation on a hard-sphere reference and Rice–Allnatt (RA) transport theory is a standard sp-band liquid-metal viscosity pipeline. We apply it to the nine post-transition sp metals tabulated by Zahid et al. (Zn, Cd, Hg, In, Tl, Sn, Pb, Sb, and Bi) over the Assael IUPAC validity ranges. Two systematic features emerge. (i) For all nine metals the calculated viscosity ηcalc decreases with temperature a factor of 2.4–6.3 more slowly than experiment (ηexp). (ii) The ratio ηcalc/ηexp evolves coherently from 0.42–0.83 near the melting temperature to 1.07 ± 0.20 at the upper temperatures, a near-unity crossover reached by seven of the nine metals within their validity ranges. These findings delimit the pipeline’s applicability by quantifying a diagnostic stiffening of the temperature gradient, and provide a component-resolved benchmark for dynamic or many-body extensions of liquid-metal transport theory.
The acoustic nonlinearity parameter and its excess values were evaluated for binary mixtures of 2-ethoxyethanol with 2-pyrrolidinone and N-methylacetamide over the complete composition range at 303.15, 313.15 and 323.15 K using Tong - Dong, Beyer, Beyer - Tong - Dong, Hartmann, Ballou, Lu, Endo, Moelwyn - Hughes, and Sharma models. The excess nonlinearity parameter exhibited predominantly negative deviations for most models, indicating significant heteromolecular interactions and non-ideal mixing behaviour in both systems. The observed nonlinear acoustic behaviour therefore reflects the combined influence of molecular compressibility, structural rearrangement and relaxation effects. The magnitude of deviations increased with temperature, indicating weakening of molecular association due to thermal agitation. Redlich - Kister polynomial fitting was employed to correlate the excess values, and the fitted coefficients showed good agreement. The results demonstrate the usefulness of acoustic nonlinearity parameters in understanding nonlinear compressibility behaviour, structural rearrangement and intermolecular association in associating liquid mixtures.
This study involved the measurements of density (rho), speed of sound (c) and refractive index (nD) for three binary liquid mixtures of Bromobenzene (BB) with 1-heptanol, 1-octanol, and 1-nonanol. The measurements were conducted over a temperature range from 298.15 to 323.15 K, with an interval of 5 K and a pressure of 0.1 MPa. The excess volume (VE), isentropic compressibility (ks), excess isentropic compressibility $(k_s<<^>>E)$(ksE) and excess refractive index $(n_D<<^>>E)$(nDE) were derived from experimental results and fitted to the Redlich-Kister polynomial equation. Furthermore, PC-SAFT method was used to estimate the theoretical densities of BB + 1-alkanol binary systems. Moreover, the measured data were also analyzed with Fourier Transform Infrared (FT-IR) spectroscopy, an effective technique for elucidating the molecular interactions in binary liquid mixtures. Adopting the DFT/B3LYP/6-311++ G(d, p) level of theory was employed to ascertain the optimised geometric structures of the pure compounds along with their complexes.
This study investigates the thermophysical and transport properties of binary liquid mixtures of 3-dimethylamino-1-propylamine (DMAPA) with three cyclic ketones: 2,6-dimethylcyclohexanone (DMCN), 2-methylcyclohexanone (MCN) and cyclohexanone (CN). Density, viscosity, and speed of sound were measured over 303.15-313.15 K at atmospheric pressure. From these data, excess molar volume (VE), isentropic compressibility deviation (kappa sE), viscosity deviation (triangle eta) and excess Gibbs free energy of activation (triangle G*E) were evaluated. The results are interpreted in terms of intermolecular interactions, emphasising hydrogen bonding between the amino (-NH2) group of DMAPA and the carbonyl (C = O) group of ketones, along with dipole - dipole interactions and charge-transfer complex formation. The effect of methyl substitution on the cyclohexanone ring is analysed to assess steric hindrance and packing efficiency. The Jouyban - Acree model was applied to correlate density and speed of sound data, and its reliability was confirmed using mean relative deviation (MRD) and individual relative deviation (IRD), showing excellent agreement.
Refractive indices (n(D)) and densities (rho) of ternary mixtures of sucrose, alcohol and water were experimentally determined at 293.2 K in all the possible homogeneous mixing regions. From densities the specific volumes (v(sp)) of the mixtures were calculated and reported. All these properties were correlated by means of the Jouyban-Acree model. The computed sub-binary model constants of the Jouyban-Acree model were used to predict the physicochemical properties of the ternary mixtures. The proposed models were tested using the experimentally measured data of the binary/ternary mixtures. The mean relative deviations (MRDs) between computed and experimental data are used as an accuracy criterion. The overall MRDs for n(D), rho and v(sp) of the investigated mixtures are 0.028%, 0.088% and 0.088%, respectively.
Mole fraction solubilities have been spectrophotometrically determined at 298.15 K for dehydroacetic acid dissolved in cyclohexane, methoxycyclopentane, in nine more alcohols (1-hexanol, 1-heptanol, 1-octanol, 2-butanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-pentanol, 4-methyl-2-pentanol, 2-ethyl-1-hexanol), and in four more alkyl alkanoates (isopropyl acetate, tert-butyl acetate, pentyl acetate and methyl butyrate) based on the Beer-Lambert law. The measured mole fraction solubilities, combined with the published solubility data retrieved from the chemical literature, are used to calculate Abraham model solute descriptors. The experiment-based descriptor values indicate that the hydrogen atom on the hydroxyl functional group forms an intramolecular hydrogen bond with one of the lone electron pairs on the oxygen atom of a neighbouring carbonyl (>C=O) functional group.
Thermophysical properties and FTIR spectra of n-propyl acetate + glycol mixtures are examined to explore the molecular interactions existing therein. By using, the measurements of densities and speeds of sound of n-propyl acetate (PAc) + diethylene glycol (DEG), + triethylene glycol (TEG) and + tetraethylene glycol (TTEG) binary mixtures across the entire range of composition at temperatures, T/K= (293.15-323.15) and pressure, p = 100 kPa. Various excess properties were evaluated using the experimental data. The partial molar volume/compressibility; excess partial molar volume/compressibility of the components over entire composition range and at infinite dilution were also calculated. These parameters were interpreted in terms of molecular interactions in these systems. Also, the speeds of sound were estimated theoretically using various theories/relations and the results were equated to experimental data. Furthermore, the FT-IR spectra of pure PAc, pure TEG and near equimolar PAc + TEG mixture were examined to confirm intermolecular interactions.
