Investigation on interaction of quinoline with primary alcohols: An understanding on dielectric dispersion and relaxation dynamics over a wide frequency regime

Abstract

The complex dielectric properties of quinoline with methanol and ethanol in solution state were studied in the microwave frequency (10 MHz-30 GHz) at different temperatures (303 K- 288 K) by decreasing 5 K steps using Time Domain Reflectometry (TDR). The complex spectra obtained is used to elucidate the dielectric behaviour of quinoline with solvents. The relaxation time and static dielectric constant determined expresses the relaxing properties of solution. The dielectric permittivity over the entire frequency provides the dielectric dispersion of quinoline complex. The inter and intra molecular interactions are facilitated by the π-electron cloud of aromatic ring and replacement of hydrogen takes place in the nitrogen in the fused ring of quinoline. The correlation factors (g and geff), Bruggeman factor and excess permittivity of the complex mixture envisage the molecular orientation and interaction respectively. The thermal parameters enthalpy, entropy and Gibb’s free energy were determined from the obtained dielectric parameters. The FT-IR spectral assignments indicate the molecular interactions among the constituent of the complex mixture.