Synthesis, Crystal Growth, Structure, Spectral, Optical and Thermal Characterization of M-Toluidinium Picrate Single Crystal

A new charge transfer molecular complex salt of picric acid with m-toluidine was synthesized and the structure confirmed by single crystal X-ray diffraction (XRD) and NMR spectral analyses. Single crystals of m-toluidinium picrate have been grown by slow solvent evaporation solution growth technique using ethanol as the solvent at ambient temperature. The single crystal XRD analysis of MTP salt confirms the formation of 1:1 charge transfer salt in which the constituent ions are held together by strong intermolecular N-H-O type hydrogen bonds. The title compound crystallizes in monoclinic crystal system with centrosymmetric space group P21/c. The optical properties were studied by the UV-Vis-NIR transmittance and the fluorescence emission studies. Fourier transform infrared (FT IR) spectral analysis was used to confirm the presence of various functional groups in the grown crystal. Thermal stability of the grown MTP crystal was established using the thermo gravimetric and differential thermal analysis.