Dielectric relaxation phenomena of rigid polar liquid molecules under gigahertz electric field

The dielectric relaxation phenomena of rigid polar liquid molecules chloral and ethyltrichloroacetate (j) in benzene, n-hexane and n-heptane (i) under 4.2, 9.8 and 24.6 GHz electric fields at 30 degreesC are studied to show t he possible existence of double relaxation times tau (2) and tau (1) for ro tations of the whole and the flexible parts of molecules. The probability o f showing double relaxation is more in aliphatic solvents indicating their nonrigidity. The symmetric and asymmetric distribution parameters gamma and delta are obtained from chi (ij)'/chi (0ij) and chi (ij)"/chi (0ij) at w(j ) --> 0 where chi (ij)' and chi (ij)" are real and imaginary parts of the c omplex orientational susceptibility chi (ij)* and chi (0ij) is the low freq uency susceptibility which is real. chi (ij)'s are involved with the measur ed dielectric relative permittivities epsilon (ij)', epsilon (ij)", epsilon (0ij) and epsilon (infinity ij) of solutions. The theoretical weighted con tributions c(1) and c(2) towards dielectric dispersions by Frohlich's metho d are compared with the experimental ones obtained from the graphical varia tion of chi (ij)'/chi (0ij) and chi (ij)"/chi (0ij) with weight fractions w (j)'s at w(j --> 0). The measured dipole moments mu (2) and mu (1) of the w hole and the flexible part of a polar molecule in terms of the linear coeff icients beta 's of chi (ij)''s with w(j)'s and the estimated tau (2) and ta u (1) reveal their associations with aliphatic solvents. The theoretical di pole moments mu (theo)'s from the available bond angles and bond moments of the substituent polar groups of the molecules with the estimated mu 's sug gest the mesomeric, inductive and electromeric effects in them under GHz el ectric field.