Supramolecular co-crystal of 4-dimethyl aminopyridine with Picric acid (4DMAP: PA): Synthesis, single crystal investigation, HF/DFT inspection, Hirshfeld surface and antifungal activity

4-Dimethylaminopyridine-Picric acid (4DMAP:PA) co-crystals were synthesized by slow evaporation technique using C 2 H 5 OH as the solvent. The molecular structure has been characterized using spectroscopic and single crystal X-ray diffraction techniques. The molecule contains O–H…O, O–H…N, C–H…O and π…π interactions. The C12–H12…O4A and C12A–H12A…O4 forms a dimer with a R22(10) graph set motif. Few intermolecular C–H…O and O–H…N bonds result in the formation of a R22(9) ring motif. The structure has been theoretically optimized by using Hartree-Fock (HF) and density functional theory (DFT) approaches. The DFT calculation led to the investigation of FMO, MEP, Mulliken charges and HOMO – LUMO, energy gap. The Hirshfeld surface (HS) and fingerprint plots analysis provided an insight in the molecular shape and visual assessment of the intermolecular interactions in the crystal structure. The co-crystal suggests antifungal activity against the fungal pathogens when compared with the standard antifungal drug fluconazole.