Synthesis, structural, hirshfeld surface, spectroscopic studies and quantum chemical calculation of the proton transfer complex between 2-amino-4-hydroxy-6-methylpyrimidine and salicylic acid

The proton transfer (PT) complex of 2-amino-4-hydroxy-6-methylpyrimidine (AHMP) with salicylic acid (SA) has been synthesized and their crystal has been grown by slow evaporation technique. Further, the crystal has been investigated by single crystal X-ray diffraction (SCXRD). The complex crystallizes in the orthorhombic centrosymmetric space group Pbca. The vibrational spectra of PT complex and its constituents have been analysed in the solid phase. UV-Vis and (HNMR)-H-1 spectra of PT complex and its constituents (SA and AHMP have been studied in solution phase. Thermal stability of PT complex has been examined by thermal gravimetric and differential thermal analysis (TG/DTA). The intermolecular interactions and their contribution to the crystal formation have been analysed with the help of 3D Hirshfeld surface and 2D fingerprint plot. The theoretical calculations of the PT complex have been carried out using DFT/TD-DFT methods to support the experimental results as well as to explore various molecular properties such as frontier molecular orbitals, natural atomic charges, chemical reactivity and molecular electrostatic potential mapping (MEP). (C) 2018 Elsevier B.V. All rights reserved.