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.

Venkatachalam Subramanian

Department Of Physics

Vemuri Rama Krishna Murthy

Amines

dipole moment

Hamiltonians

Organic solvents

Permittivity

Propanol

quantum theory

Relaxation time

COMPLEX PERMITTIVITY

Dielectric analysis

HAMILTONIAN CALCULATIONS

Binary mixtures

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

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.

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

The molecular interactions between the polar systems propan-2-ol with alkyl benzoates (methyl benzoate and ethyl benzoate), for various mole fractions and different temperatures, were studied by determining the dielectric permittivity using a LF impedance analyzer and Abbe's refractometer in the static and optical frequency regions, respectively. The effective Kirkwood correlation factor, corrective Kirkwood correlation factor, dipole moment, excess dipole moment, and excess Helmholtz free energy were calculated using the experimental data. Hamiltonian quantum mechanical calculations (ab initio and semiempirical)were performed using PC Spartan and Argus lab Modeling software for both pure and equimolar binary systems of propan-2-ol with alkyl benzoates. © Springer Science+Business Media, LLC 2011.

Journal of Solution Chemistry

Investigations on binary mixtures of propan-2-ol with methyl benzoate and ethyl benzoate

The dielectric relaxation time of liquids and the spin-lattice relaxation time from NMR studies are related to one another since the rotational correlation time (τc) is a function of the dielectric relaxation time τ. The present study attempts to correlate the observations from the two studies along with inputs from conformational analysis, for the binary systems of methanol + ketones. The results are analysed with respect to the rotation of the CH3 group. © 2005 Elsevier B.V. All rights reserved.

Journal of Molecular Liquids

Dielectric and 13C NMR studies of hydrogen-bonded binary systems of methanol + ketones

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.

Molecular Physics

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

A conformational study on the 1:1 binary complex of acetone-methanol involving hydrogen bonding has been carried out using ab initio calculations on three isomers. The optimization uses a 3-21G basis set and the single run calculation is done at the 4-31G and 6-31G basis set levels. The circular double hydrogen bonded six membered structure is found to be stable. The calculated dipole moment is compared with the experimental value. The dipole moment of the system was measured at three microwave and one r.f. frequencies using Guggenhiem's method. © 1995.

Journal of Molecular Structure: THEOCHEM

Conformational study on the binary mixture acetone-methanol involving H-bonding

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

To derive the expression for complex dielectric and magnetic susceptibilities, an easy and alternate approach is proposed. This analysis is based on the assumption that the cavity is equivalent to an isolated lumped resonant circuit. The results are identical with standard expressions. Results of a few samples are also tabulated. © 1989.

Journal	Journal of Molecular Structure
ISSN	00222860
Open Access	No