Dielectric properties of amino substituted pyridines in dilute solutions of some non-polar solvents at different temperatures

Abstract

Microwave dielectric absorption and relaxation behaviour of each of 2-aminopyridine and 4-dimethylaminopyridine in non-polar solvents benzene, carbon tetrachloride and 1,4-dioxane have been studied at 303.15 K, 313.15 K and 323.15 K temperatures. X-band microwave bench operating at 9.1 GHz has been used for determination of dielectric constant (ε') and dielectric loss (ε"). The static permittivity (ε₀) at 2 MHz and permittivity at optical frequency (ε_∞) have also been determined. The measured values of dielectric permittivity (ε') and dielectric loss (ε") have been used to evaluate relaxation time (τ), dipole moment (μ), molar volume (V_m) and molar polarization of solute (P₂). Present study suggests the existence of intra-molecular and overall rotation of the amino pyridine molecules in the non-polar solvents. The solute–solvent molecular associations have been predicted. The effect of solvent environments on the relaxation behaviour of the amino pyridines has also been discussed.