Synthesis, crystal structure, growth, optical and third order nonlinear optical studies of 8HQ2C5N single crystal - An efficient third-order nonlinear optical material

A neoteric organic third order nonlinear optical material 8-hydroxyquinolinium 2-chloro-5-nitrobenzoate dihydrate (8HQ2C5N) was grown by slow cooling technique using ethanol: water (1:1) mixed solvent. The calculated low value of average etch pit solidity (4.12 × 103 cm−2) indicated that the title crystal contain less defects. From the single crystal X-ray diffraction data, it was endowed that 8HQ2C5N crystal belongs to the monoclinic system with centrosymmetric space group P21/c and the cell parameters values, a = 9.6546 (4) Ǻ, b = 7.1637(3) Ǻ, c = 24.3606 (12) Ǻ, α = γ = 90°, β = 92.458(2)° and volume = 1683.29(13) Ǻ3. The FT-IR and FT-Raman spectrum were used to affirm the functional group of the title compound. The chemical structure of 8HQ2C5N was scrutinized by 13C and 1H NMR spectral analysis and thermal stability through the differential scanning calorimetry study. Using optical studies the lower cut-off wavelength and optical band gap of 8HQ2C5N were found to be 364 nm and 3.17 eV respectively. Using the single oscillator model suggested by Wemple – Didomenico, the oscillator energy (Eo), the dispersion energy (Ed) and static dielectric constant (εo) were estimated. The third-order susceptibility were determined as Im χ(3) = 2.51 × 10−5 esu and Re χ(3) = 4.46 × 10−7 esu. The theoretical third-order nonlinear optical susceptibility χ(3) was calculated and the results were compared with experimental value. Photoluminescence spectrum of 8HQ2C5N crystal showed the yellow emission. The crystal had the single shot laser damage threshold of 5.562 GW/cm2. Microhardness measurement showed that 8HQ2C5N belongs to a soft material category. [Display omitted] •A new organic single crystals were grown and the crystal structure was reported.•Crystal possess, good transmittance, thermal and mechanical stability.•Single shot LDT value is found to be higher than that of KDP and Urea.•Large χ(3) suggests the material for high frequency ultrafast optical switches.•PL study suggests that it can be used as a new yellow light emitting material.