Synthesis, Spectroscopic, and DFT Study of a Novel Hydrogen Bonded Charge Transfer Complex Derived from Melamine and 1,4-Dinitrobenzene

This research involved spectroscopic and computational investigations of a new charge-transfer complex (CTC) formed through hydrogen bonding between melamine ( MA ) as the electron donor and 1,4-dinitrobenzene ( DNB ) as the electron acceptor. The obtained CTC has the general formula C 9 H 10 N 8 O 4 with a 1:1 acceptor: donor molar ratio. The structure and properties of the [MA(DNB)] complex were examined using 1 HNMR, 13 CNMR, FTIR, UV-vis techniques, and elemental analysis (CHN). The results confirm that this complex has been successfully produced and is stable. Density Functional Theory (DFT) studies, including FMO orbitals, quantum chemical parameter s , NLO, and spectral analysis, employed the B3LYP function with the 6-311G(d,p) basis sets for computational analysis. Additionally, the reduced density gradient (RDG), natural bonding orbital (NBO), and molecular electrostatic potential (MEP) surfaces were studied to understand intermolecular interactions in the gas phase of [MA(DNB)] complex molecules. Moreover, thermodynamic parameters, including Gibbs free energy change (ΔG 0 ), enthalpy change (ΔH 0 ), and entropy change (ΔS 0 ), were determined at room temperature.