Self-assembled supramolecular structure of 1-methyl piperazinium 4-nitrophenolate 4-nitrophenol monohydrate single crystal: Synthesis, growth, thermal and photo physical properties

A new photoactive organic crystal, 1-methyl piperazinium 4-nitrophenolate-4-nitrophenol monohydrate (MP4NPM) has been synthesised at 35 °C. Good quality single crystals of MP4NPM have successfully been grown by slow evaporation solution growth technique. Single crystal X-ray diffraction analysis shows that MP4NPM belongs to monoclinic crystal system with space group P21/n. The molecular structure was further confirmed by modern spectroscopic techniques like FT-NMR (both 1D and 2D), FT-IR, UV-Vis-NIR and fluorescence. The UV-Vis-NIR spectrum was performed to understand the range of optical transparency and the results showed its suitability for nonlinear optical applications. Fluorescence emission revealed that MP4NPM can serve as a photo active material. Thermal properties of MP4NPM were investigated using simultaneous TG-DSC analysis. Frequency and temperature dependent dielectric properties were studied in the frequency range 500 Hz-5 MHz and 40-50 °C, respectively. Vicker's microhardness measurements revealed that MP4NPM belongs to the category of soft material. Kurtz and Perry powder technique shows that MP4NPM has SHG efficiency 0.89 times that of potassium dihydrogen phosphate (KDP).