Synthesis, crystal structure, vibrational spectra, optical properties of disubstituted benzyl triphenylphosphinium picrate: Experiment and DFT/TDDFT calculations

Abstract

A new organic hybrid material, 2,4-dichlorobenzyl triphenylphosphinium picrate, [2Cl4ClBzTPP][PIC](1), has been grown by slow evaporation solution growth technique, and characterized by elemental analysis, spectroscopy, thermal analysis, powder and single crystal XRD. The composite belongs to monoclinic system with space group P2(1)/c, and consists of a pair of [2Cl4ClBzTPP]+ cations and picrate anions. The experimental vibrational bands (IR and Raman) have been discussed and assigned based on DFT calculations. The HOMO-LUMO energy gap explains the charge transfer interactions in the molecule. TG-TDA technique reveals that the title crystal was stable up to 168 °C. The fluorescence spectra reveal that the compound shows violet and green fluorescence emissions at 377 and 509 nm upon excitation at 250 nm in solid state at room temperature. The energy of weak interactions in the molecule and nonlinear optical properties were studied using DFT calculations.