Synthesis, growth, structural characterization and biological investigation of hydrogen bonded organic molecular salt: N, N-diethylanilinium-5-sulphosalicylate

Abstract

N, N-diethylanilinium-5-sulphosalicylate was successfully synthesized and good optical quality single crystals were grown employing slow solvent evaporation solution growth technique at ambient temperature. The CHN analysis indicates that the titled crystal is composed of stoichiometric proportion of the constituent ions, free from impurities and devoid of water molecules. The UV–Visible absorption spectrum exhibits the bands due to π-π* and n- π* transitions occurring in the salt. FT-IR spectral studies were performed to identify the different vibrational modes present in the titled crystal. The formation of salt and the molecular structure were initially confirmed by 1H and 13C NMR spectroscopic Studies. Single crystal XRD analysis indicates that the titled crystal belongs to monoclinic crystal system with centrosymmetric space group, P21/c. The hydrogen bonding parameter reveals that the salt crystal possesses N–H⋯O, O–H⋯O and C–H⋯O types of hydrogen bonding which are responsible for the stabilization of the crystal structure. TG/DTA Analyses reveal that the crystal is thermally stable up to 270 °C. The Vickers microhardness study reveals the soft nature of the titled crystal. Further, the titled salt was screened for its antimicrobial and antioxidant activities. The antimicrobial studies reveal that the synthesized salt has significant antibacterial and antifungal activities comparable to the standard compounds. The antioxidant activities of the titled salt show that the synthesized salt exhibits moderate activity against DPPH radical.