Structures and Electrical Properties of Some Biologically Active Nucleic Acid Constituents

Volume 3 - Issue 5

MS Masoud¹*, MSh Ramadana¹, AH Elsayedb², AM Sweyllamb² and MH Al-Saifyc³

Received: September 10, 2018;   Published: September 25, 2018

DOI: 10.32474/AOICS.2018.03.000172

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Abstract

Zinc II, cadmium II and mercury II complexes derived from barbituric acid (BA), 5-nitrobarbituric acid (NBA), phenobarbital (PB) and 2-thiouracil (TU) were synthesized. The analytical results assigned the formation of complexes with the stoichiometries 1:1 and 1:2. The infrared spectral measurements assigned, and bands. The tetrahedral geometries are given for these complexes. The capacitance (CP) and the dielectric constant of the complexes are decreased with increasing the applied frequency and increased with increasing temperature. The behavior of the dielectric loss (εs) indicated a polar polarization mechanism. The loss tangent (tan δ) is decreased with increasing frequency and increased with increasing temperature while the impedance (Z) is mostly decreased with increasing both of frequency and temperature. Cole-Cole diagrams for the complexes at different temperatures reveal non- Debye type of the complexes. The relaxation time (τ) for each relaxator becomes smaller as the temperature increases. In most complexes, the conductivity – temperature relationship is characterized by a phase transition temperature. Two pathways for the conduction of electricity may be expected at lower and upper temperature regions: n → Π* and Π → Π* transitions, respectively. The relative permittivity, dielectric loss and conductivity values for the complexes revealed semiconducting features based mainly on the hopping mechanism. The lower values of the activation energy (ΔE) may be understood assuming that the metal ion forms a bridge with the ligands, thus facilitating the transfer of current carriers with some degree of delocalization in the excited state.

Keywords: Ligands and Complexes; IR Spectra; Dielectric Properties; Electrical Conductivity; Cole-Cole Diagrams and Activation Energy

Abstract| Introduction| Experimental| Results and Discussion| B- Dielectric and Electrical Conductivity Measurements| References|