The molecular interaction between the polar systems of isobutanol and aniline for various mole fractions at different temperatures were studied by determining the frequency dependent complex dielectric permittivity by using the open-ended coaxial probe technique method in the microwave frequency range from 20 MHz to 20 GHz. The geometries are optimized at HF and B3LYP with 6-31G and 6-31G+ basis sets. Dipole moments of the binary mixtures are calculated from the dielectric data using Higasi's method and compared with the theoretical results. Conformational analysis of the formation of hydrogen bond between the isobutanol and aniline is supported by the FT-IR and molecular polarizability calculations. The average relaxation times are calculated from their respective Cole-Cole plots. The activation entropy, activation enthalpy and Kirkwood correlation 'g' factor, excess permittivities E), Bruggeman parameters (fB) have also been determined for isobutanol and aniline and the results were correlated. © 2012 Elsevier B.V. All rights reserved.

Vemuri Rama Krishna Murthy

Ab initio Calculations

ACTIVATION ENTHALPIES

ACTIVATION ENTROPIES

Basis sets

COLE-COLE PLOTS

COMPLEX DIELECTRIC PERMITTIVITIES

Conformational analysis

DIELECTRIC DATA

EXCESS PERMITTIVITY

Frequency dependent

HF AND B3LYP

ISOBUTANOL

KIRKWOOD CORRELATION

KIRKWOOD CORRELATION FACTORS

MICROWAVE DIELECTRIC RELAXATION

MICROWAVE FREQUENCY RANGES

Mole fraction

MOLECULAR POLARIZABILITIES

OPEN-ENDED COAXIAL PROBE

POLAR SYSTEMS

Theoretical result

Binary mixtures

dipole moment

Hydrogen bonds

Permittivity

Relaxation time

aniline

INSECTIVORA

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Molecular Structure

Complex dielectric permittivity measurements of propylene glycol (PG) in ethanol at various mole fractions were measured by using open-ended coaxial probe technique at different temperatures in the frequency range 0.02 &lt; ν/GHz &lt; 20. The dipole moment (μ), excess dipole moment (Δμ),excess permittivity (εE), excess inverse relaxation time(1/τ)E, Bruggeman parameter (fB), excess Helmholtz energy (ΔFE) are determined using experimental data. From the minimum energy based geometry optimization, dipole moments of individual monomers of propylene glycol and ethanol and their binary system have been evaluated theoretically at gaseous state as well as alcoholic medium by using PCM and IEFPCM solvation models from the Hatree-Fock (HF) and Density Functional Theory (DFT-B3LYP) methods with 6-311G* and 6-311G** basis sets. The obtained results have been interpreted in terms of the short and long range ordering of the dipoles, Kirkwood correlation factor (geff), thermodynamic parameters, mean molecular polarizability (αM) and interaction in the mixture through hydrogen bonding. © 2017 Elsevier B.V.

Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy

Microwave dielectric relaxation spectroscopy study of propylene glycol/ethanol binary mixtures: Temperature dependence

The dielectric behaviour of the polar liquids like propionaldehyde, isopropyl amine and their equimolar binary mixture in nonpolar solvent benzene is studied in the microwave frequency range using the cavity perturbation technique at 6.218 GHz (J band), 9.880 GHz (X band), 16.331 GHz (P band) and 24.951 GHz (K band). Hamiltonian quantum mechanical calculations such as AM1, PM3, and MNDO optimized converged geometry operation is performed by using Argus lab chemical modelling software 2004 for both pure and binary systems of propionaldehyde and isopropyl amine. Dipole moments of the binary mixtures are calculated from the dielectric data using Higasi's method and compared with the theoretical results. Conformational analysis of the formation of a hydrogen bond between the propionaldehyde and isopropyl amine is supported by FT-IR, proton NMR spectra and molecular polarizability calculations. The average relaxation times are calculated from their respective Cole-Cole plots.

Molecular Physics

Conformational and microwave dielectric relaxation studies of hydrogen bonded polar binary mixtures of propionaldehyde with isopropyl amine

The dielectric behavior of the polar liquids like propan-1-ol, isopropyl amine and their equimolar binary mixture in nonpolar solvent benzene is studied in the microwave frequency range using the cavity perturbation technique at 6.218 GHz (J band), 9.880 GHz (X band), 16.331 GHz (P band) and 24.951 GHz (K band). Hamiltonian quantum mechanical calculations such as AM1, PM3, and MNDO optimized converged geometry operation is performed by using Argus lab chemical modeling software 2004 for both pure and binary system of propan-1-ol and isopropyl amine. Dipole moments of the binary mixtures are calculated from the dielectric data using Higasi's method and compared with the theoretical results. Conformational analysis of the formation of hydrogen bond between the propan-1-ol and isopropyl amine is supported by the FT-IR and proton NMR spectra. The average relaxation times are calculated from their respective Cole-Cole plots. © 2008.

Conformational and dielectric analysis of hydrogen bonded polar binary mixtures of propan-1-ol with isopropyl amine

The reorientation activation energies of five methanol + ketone systems were determined from the study of the variation of dielectric permittivity with temperature between 303 to 333 K at X band frequency. The results of the activation parameters are interpreted in terms of the rotation of the molecules about the C-O-H hydrogen bond, using a previously reported conformation obtained from semi-empirical and ab initio calculations as the basic conformer. The ketones studied are acetone, 2 butanone, 3 pentanone, cyclohexanone and acetophenone.

Physics and Chemistry of Liquids

Effect of steric hindrance of ketones in the dielectric relaxation of methanol+ketone systems

The dielectric properties of the hydrogen bonded binary system of non-associated polar liquid methyl benzoate (ester) and associated polar liquid N-methylaniline (secondary amine) were studied on both pure and equimolar binary mixtures of methyl benzoate and N-methylaniline in dilute solutions of benzene. AM1 semi-empirical calculations were performed on various conformers of the hydrogen bonded complex. The minimum enery conformer was selected and self-consistent reaction field calculations were performed on the resultant geometry to include solvent effects. The experimental value of dipole moment is compared with the calculated value for the conformers.

Conformational and dielectric analysis of hydrogen bonded polar binary mixtures of methyl benzoate with N-methylaniline

The excess parameter studies in the microwave frequency region (X-band) on complex dielectric permittivity for the binary mixtures are reported. The methods employed are fixed cavity perturbation technique and adjustable plunger cavity technique. Also Gopalakrishna method is used to calculate the relaxation time of the polar solute in a non-polar solvent. The samples under study are acetonitrile, chlorobenzene, dimethyl formamide, carbon tetrachloride and benzene. © 1993 the Indian Academy of Sciences.

Pramana

Dielectric studies of some binary liquid mixtures using microwave cavity techniques

Microwave dielectric relaxation studies of hydrogen bonded polar binary mixtures of isobutanol and aniline

Journal	Journal of Molecular Structure
ISSN	00222860
Open Access	No