Bal Krishna

Experimental and Theoretical Aspects of Higasi's Equation for a Quick Determination of Electric Dipole Moment in Solution

In the present investigation the authors have determined the electric dipole values for twenty‐three organic solutes according to Higasis method. Except for two substances, viz., iodoform and ethylene dibromide, the dipole values so obtained agree fairly well with those obtained by usual methods. A reassessment of Higasis equation has been made on theoretical grounds and a more general equation has been obtained.

Range of Validity of Higashi's Equation for a Quick Determination of Dipole Moment in Solution

The present authors have discussed the range of validity of Higashis equation for determining the electric dipole moment of a substance in a nonpolar solvent. Mathematical analysis shows that Higashis equation is valid for the straight part of the curve showing the variation of the dielectric constant of the solution with the mole fraction of the solute. With the six organic solutes examined the above conclusion is found to be valid for four, viz., chlorobenzene, ortho‐dichlorobenzene, nitrobenzene, and methylene chloride. Ethylene dichloride and ethylene dibromide whose molecules are subject to restricted rotation, show anomalous results. It is likely that Higashis equation may not be applicable to such molecules. Benzene was used as a solvent throughout.

Dielectric study of esters: electric dipole moments and molecular configuration

Abstract Electric dipole moments of ethyl isobutyrate, ethyl cyanoacetate, dibutyl o -phthalate, and diethyl butylmalonate (diethyl 2- n -butyl-propanedioate) in benzene solution and those of phenyl acetate and ethyl bromoacetate in carbon tetrachloride solution have been determined at 30 °C, using Halverstadt—Kumlers standard method. The moments of these esters have also been calculated theoretically and the results interpreted in terms of their molecular configuration.

Calculation of ionization potential of some alternant hydrocarbon molecules and radicals by extended Hückel theory

The extended Huckel theory developed by F. E. Harris has been used to calculate the ionization potential of some alternant hydrocarbon molecules and radicals; the values so obtained have been compared with those calculated by Poples SCF MO theory and also with the ones obtained experimentally.

Dielectric study of amines: electric dipole moments, solute–solvent interactions, and molecular configuration

The electric dipole moments of di-s-butylamine, 2,3-dichloroaniline, N-ethyl-o-toluidine, and N-ethyl-m-toluidine have been determined in benzene and carbon tetrachloride at 30 °C. The effect of solvents on the dipole moments has been examined in the light of Higasis theory of solute–solvent interaction. The molecular moments have also been calculated by vector-summation methods and the results discussed in terms of the molecular configuration.

Dielectric study of esters in benzene: internal rotation and molecular configuration

Electric dipole moments (µ) at 25° have been determined for phenethyl butyrate, phenethyl phenylacetate, pentyl benzoate, pentyl formate, and pentyl butyrate at a frequency of 1 MHz, and for phenethyl butyrate, phenethyl phenylacetate, phenylpropyl butyrate, pentyl phenylacetate, and pentyl cinnamate at a microwave frequency of 3·38 GHz. Relaxation times (τ) at 25° have been calculated, and Eyrings equation has been used to obtain values for the heat (ΔH*) and free energy (ΔG*) of activation. The values of µ and τ have been interpreted in terms of internal rotation and molecular configuration.