Synthesis, crystal structure, optical, thermal, mechanical, dielectric and DFT studies of 3, 5-dimethylprazole:1,3,5-benzene tricarboxylic acid molecular adduct crystal

An organic molecular adduct, 3, 5-Dimethylpyrazole:1,3,5-benzene tricarboxylic acid was synthesized and single crystals grown in methanol-acetone (1:1) solvent mixture by slow solvent evaporation solution growth technique at room temperature. The formation of the molecular adduct and crystal structure have been confirmed by single crystal X-ray diffraction studies and NMR spectroscopic techniques. Further, the title crystal belongs to monoclinic crystal system with space group, P21/c and the supramolecular architecture of adduct involves extensive intermolecular O-H�N, N-H�O, O-H�O and C-H�O hydrogen bonding interactions. UV�Vis-NIR spectrum was recorded to find out the lower cut-off wavelength, percentage transmission and optical band gap energy. The fluorescence properties of the title crystal were identified by Photoluminescence spectral studies. Fourier transform infrared (FT-IR) spectral analysis was carried out to confirm the presence of various functional groups in the grown crystal. The quantum chemical analyses were performed by density functional theory (DFT) using B3LYP/6-311G (d,p) basis set. The thermal and mechanical properties of the grown crystal have been investigated by TG/DTA analyses and Vickers micro hardness measurement, respectively. The dielectric behaviours of title single crystal have also been investigated as a function of frequency at different temperatures