Green synthesis, characterization and some physicochemical studies on cocrystal; 2-(4-(Dimethylamino) benzylideneamino) benzoic acid and p-nitroaniline system

摘要

Phase diagram of 2-(4-(Dimethylamino) benzylideneamino) benzoic acid (DMABAB) and p-Nitro aniline (PNA) system, determined by the thaw-melt method gives two eutectics and an inter-molecular compound (IMC)/cocrystal with congruent melting point. It was structurally characterized by X-ray crystallography methods. The cocrystal shows synthonic interactions with N[sbnd]H⋯O bridge to the centroid of an adjacent molecule. The synthon also shows interesting N[sbnd]H⋯C and H (N)⋯O interactions. It was noted to emit significantly high dual fluorescence with large Stokes shift and high quantum efficiency. Measurement of the solubility of the cocrystal was studied in the range from 300 to 315 K. Reasonably large sized cocrystal was grown by slow evaporation technique and optical band gap and refractive index were also calculated with the help of transmittance spectra. Some physicochemical properties (enthalpy of dissolution, entropy of dissolution and enthalpy of mixing) of cocrystal were also estimated with the help of solubility data.