Growth, structural, spectral, optical and thermal studies of a novel third-order nonlinear optical single crystal: Piperazine-1,4-diium bis(2, 4-dichlorobenzoate)

Abstract

A novel third-nonlinear optical (NLO) crystal, piperazine-1,4-diium bis(2,4-dichlorobenzoate) (abbreviated as PBDCB) was successfully synthesized and grown good quality crystal by slow evaporation solution growth technique by methanol as a solvent at room temperature. The formation of the grown crystal was carried out by single-crystal X-ray diffraction analysis. The analysis of a single crystal X-ray diffraction reveals that the title compound was crystallized in the monoclinic system with centrosymmetric space group P21/c and thereof lattice parameter are a = 11.166(6) Å, b = 8.160(5) Å, c = 12.085(6) Å, β= 113.18(3)°, Z = 4. Crystallographic studies also reveal that the molecules are linked via N—H···O and C—H···Cl hydrogen bonds. Pairs of intermolecular N—H···O hydrogen bonds generate R44(12) ring motifs. The powder X-ray diffraction study was completed and the peaks were indexed. UV–Vis spectral studies were revealed that the grown crystal is transparent in the entire visible region with a lower cut off the wavelength of 286 nm. The optical band gap of the title compound was measured by Tauc's plot method, and it was obtained to be 3.9 eV, which shows suitable applications of the optoelectronic device. In the photoluminescence study, the grown crystal was revealed violet emission radiation, and thereof peak has appeared at 312 nm. The functional groups of the grown crystal have been determined by Fourier Transform Infra-Red (FTIR) spectroscopy technique. In thermogravimetric (TGA) and differential thermal analysis (DTA) analysis, the title material was determined as thermally as stable up to 163 °C. The Vickers Microhardness test ascertained the mechanical properties of the grown crystal material, and it belongs to a soft material category. The dielectric measurements of the developed crystal material were also ascertained at various frequencies. The dielectric constant, dielectric loss, and A.C. the conductivity of title material was studied with different frequencies and temperatures. The laser damage threshold (LDT) of the grown crystal was then calculated by using Nd: YAG laser. The grown crystal has given the measured (LDT) value of 8.97 GW/cm2. The third-order nonlinear optical (NLO) properties characteristics, such as absorption coefficient (β ~ 0.02 × 10−4 cm/W), the refractive index (n2 ~ 4.06 × 10−8 cm2/W), and their susceptibility range values of (χ(3) ~ 2.17 × 10−6esu) of the grown crystal was estimated by Z-scan technique, suggests that the grown crystal material PBDCB was served as a promising source for nonlinear optical devices.