Growth, crystal structure, Hirshfeld surface, spectroscopy studies and DFT calculations of an organic cocrystal of 2-amino-4-hydroxy-6-methylpyrimidine (AHMP) and 2,4-dimethylbenzoic acid (DMBA)

Abstract

A newly synthesized organic cocrystal (AHMP.DMBA) of 2-amino-4‑hydroxy-6-methylpyrimidine (AHMP) and 2,4-dimethylbenzoic acid (DMBA) was successfully grown by the slow evaporation method. The current report focuses on the molecular structure, vibrational study, thermal analysis and electronic properties of the grown crystal. The crystal structure analysis of AHMP.DMBA cocrystal was done by single crystal X-ray diffraction (SCXRD) technique. The given cocrystal crystallizes in the orthorhombic system space group Pnma. 3D Hirshfeld surface map and its associated 2D fingerprint plots have been generated for understanding the noncovalent interactions which stabilized the crystal pacing. Further, FTIR spectroscopy and B3LYP-D3/6-311++G(d,p) theory have been used to examine the vibrational modes present in the synthesized complex. The observed and simulated 13C and 1H NMR spectral analyses have also supported the structural analysis. The experimental absorption spectra and optical band gap are obtained by UV–Vis absorption spectroscopy and the theoretical electronic spectrum is computed using time dependant density functional theory (TD-DFT) method. The thermal profiles of the given sample have been recorded by thermal gravimetric/differential thermal analysis (TG/DTA). Additionally, the molecular properties i.e., HOMO-LUMO, MEP and non-linear optical parameters are also discussed.