Crystal structure, vibrational study and dielectric behavior of a new amino pyridinium selenate monohydrate [C5H7N2]2[SeO4].H2O

Abstract

The new organo-selenate compound [C5H7N2]2[SeO4].H2O abbreviate CNSe was synthesized and characterized by single-crystal X-ray diffraction at room temperature. This hybrid crystallizes in the triclinic space group P1¯ with lattice parameters: a = 6.597 (1) Å; b = 8.520 (1) Å; c = 12.684 (2) Å; α = 96.285 (8)°; β = 97.554 (6)°; γ = 95.082 (6)° v = 510.28 Å3 and Z = 2. The structure is formed by organic and mineral chains which are interlinked by two varieties of hydrogen bond, namely N–H … OT and Ow-H … OT. The two and antiparallel cations [C5H7N2]+ are arranged in a face-to-face pattern with a distance of 3.897 Å, indicating the existence of π-π interaction which makes the building of the crystal. The thermal properties studied by (TGA), (DTA) and (DSC) indicate the existence of a single mass loss which corresponds to the dehydration and decomposition of the title compound. The vibrational study confirms the presence of the different parts of this structure. The frequency-dependent electrical properties of the sample were investigated in the temperature range of 300–400 K and in the frequency range of 2–10 MHz by impedance spectroscopy. The ac conductivity has been fitted and studied using Jonscher's law, whose exponent n varied with the temperature, the conduction mechanism shows that the sample follows the non-overlapping small polaron tunneling (NSPT) model.