Structural, vibrational characterization and DFT calculations of urea: DL-malic acid (1:1) – co-crystal

•Urea - DL-malic acid 1:1 co-crystal has been synthesized.•It crystallizes in monoclinic crystal system and the space group is P 21/c.•Hirshfeld surface analysis and 2D-fingerprint plots were performed.•Experimental, theoretical, structural and spectroscopic studies have been carried out.•Electronic properties, MESP and energy of frontier molecular orbitals were calculated. The slow evaporation solution growth approach was used to generate a single crystal of urea-DL-malic acid (UDLMA). Single crystal X-ray diffraction was used for the structural analysis of obtained 1:1 co-crystal. A systematic study of structure, intra and intermolecular bonding interactions, vibration, excitation energies and electrostatic potential was carried out for the urea-DL-malic acid complex (UDLMA) using density functional theory (DFT) and the B3LYP/6-31+G* basis set. The estimated vibrational frequencies were compared to the experimental values, and they were found to be very similar. The HOMO–LUMO energy gap was calculated to be 7.152 eV, indicating that charge transfer occurs between the molecules. Descriptors of global chemical reactivity were also calculated. The molecular electrostatic potential and NBO charges were investigated. Hirshfeld surface analysis was used to visualize the many types of intermolecular interactions that govern the formation of supramolecular architecture. [Display omitted]