title: Microwave dielectric spectra and molecular relaxation in formamide-N,N-dimethylformamide binary mixtures.
abstract: The dielectric dispersion and absorption spectra of formamide (FA), N,N-dimethylformamide (DMF) and their binary mixtures are investigated in the frequency range of 500 MHz to 20 GHz at 30°C in view of the organic synthesis by microwaves heating using amides solvents. The concentration dependent values of molecular reorientation relaxation times lower than that of the ideal mixing behaviour have been attributed to the cooperative dynamics of H-bonded FA-DMF structures. The molar ratio of stable adduct is 2:1 of FA to the DMF, which is determined from the concentration dependent excess static dielectric constant and the relaxation time plots of these binary mixtures. Electrode polarization effect and ionic conduction in FA and DMF were investigated from their dielectric dispersion spectra in the low frequency region of 20 Hz to 1 MHz.
authors.affiliation: Dielectric Research Laboratory, Department of Physics, J.N.V. University, Jodhpur 342005, India. rjsengwa@rediffmail.com
authors.forename: R J
authors.initials: RJ
authors.lastname: Sengwa
authors.forename: Shobhna
authors.initials: S
authors.lastname: Choudhary
authors.forename: Vinita
authors.initials: V
authors.lastname: Khatri
mesh_terms: D004126:Dimethylformamide / Q000737:chemistry*; D004566:Electrodes; D060733:Electromagnetic Radiation; D006860:Hydrogen Bonding; D007477:Ions; D008027:Light; D008872:Microwaves; D008968:Molecular Conformation; D012997:Solvents / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods; D013696:Temperature
chemical_list: D007477:Ions; D012997:Solvents; D004126:Dimethylformamide