Synthesis, crystal structure, vibrational spectra, nonlinear optical property of an organic charge-transfer compound―4-nitrobenzyl isoquinolinium picrate based on DFT calculations

Abstract

Single crystals of an organic charge-transfer compound, 4-nitrobenzyl isoquinolinium picrate, [4NO2BzIQl][PIC](1), were grown by slow evaporation technique at room temperature. Single crystal XRD and powder XRD studies conform the crystal structure and crystalline nature. In the title compound, the [4NO2BzIQl]+ cations and the [PIC]- anions stack into a columnar structure through π···π and CH···π interactions. The FT-IR and Raman spectra were recorded and analyzed with the aid of density functional theory calculations in order to make a suitable assignment of the observed bands. The simulated spectrum satisfactorily coincides with the experimental UV–visible spectrum. Thermal stability and the major gaseous products of decomposition at 293 °C were examined by TG-DTA-MS technique. The material shows three main emission peaks about 385, 467 and 538 nm upon excitation at 241 nm in solid state at room temperature. The excited state energy from theoretical UV–vis spectra, the total energy of intramolecular interactions and nonlinear optical properties were studied using DFT calculations.