Crystallographic, dynamic and Hirshfeld surface studies of charge transfer complex of imidazole as a donor with 3,5-dinitrobenzoic acid as an acceptor: Determination of various physical parameters

摘要

The peculiar charge (CT) complex is synthesized by mixing the 1: 1 ratio of the donor, imidazole (IZ) and acceptor, 3,5-dinitrobenzoic acid (DNBA) in ethanol at room temperature. The stoichiometry of the 1: 1 proton transfer complex is obtained by using the Benesi-Hildebrand equation, which is used to determine the molar extinction coefficient (epsilon(CT)), formation constant (K-CT) and the other physical parameters. The CT complex was investigated using various spectral techniques, such as UV-visible, FTIR, (HNMR)-H-1 and powder XRD that confirm the formation of N+-H center dot center dot center dot O- bond between donor and acceptor. The Numerous thermodynamics parameters such as energy (E-CT), Ionization potential (I-D), resonance energy (RN), free energy (Delta G), oscillator strength (f) and transition dipole strength (mu(EN)) have been determined by using UV-visible spectroscopy. Structure of the synthesized CT complex has also been investigated by using X-ray crystallography. The formation of CT complex occurred by transfer of lone pair of electrons from donor to the acceptor through N+-H center dot center dot center dot O- type of hydrogen bond and structure of the CT complex has been found to be monolclinic [(IZ)(+)(DNBA)(-)] as investigated by X-ray crystallographic and other studies. The thermal decomposition and mass loss of the CT complex were analyzed by TGA-DTA studies. The Hirshfeld surfaces of the CT complex have been mapped over a d(norm), shape_index and curvedness range of -0.79 to 1.7, -0.99 to 1.0 and -4.0 to 4.0 respectively.