Structural, FTIR, FT-Raman, optical and nonlinear optical properties of organic nonlinear optical crystal –3,5-diisopropyl-2-hydroxybenzoic acid

Abstract

• The 3,5-diisopropyl-2-hydroxybenzoic acid (35D2HBA) was grown using ethanol. • The structure of the crystal grown by slow evaporation solution growth method is triclinic. • FTIR and the FT-Raman spectral analysis confirmed the purity of the samples. • Thermal stability and the melting point of the 35D2HBA grown crystal were 126 °C and 256 °C. • The band gap value of the 35D2HBA is measure as 5.649 eV. • The Second Harmonic Generation efficiency, Z-Scan, Antibacterial activities were studied. This paper mainly investigates the structural, FTIR, FT-Raman, thermal, optical and nonlinear optical properties of organic nonlinear optical crystal 3,5-diisopropyl-2-hydroxybenzoic acid (35D2HBA) . The 3,5-diisopropyl-2-hydroxybenzoic acid was grown using ethanol as solvent using a slow evaporation solution growth method. The grown crystal was characterized by structural, vibrational, thermal, optical and antibacterial analysis. XRD analysis confirmed that the grown crystal belongs to the triclinic crystal system, which belongs to the space group of p-1 with the lattice parameters a = 9.20 Å, b = 14.83 Å, c = 15.36 Å, α = 72.71°, β = 78.60°, γ = 77.10° and V = 1932 Å. The crystallinity of the grown 35D2HBA crystal was put forward through the extreme diffraction peaks of the Miller Planes. The range of functional groups and the corresponding vibrational frequencies are established using FTIR and the FT-Raman spectral analysis. Thermal stability and the melting point of the 35D2HBA-grown crystal were 126 °C and 256 °C, respectively. The UV cutoff wavelength of the grown 35D2HBA crystal was around 316 nm to confirm the benefits of the grown crystal. The band gap (5.649 eV) of the grown 35D2HBA crystal is calculated from the Tauc plot. The nonlinear optical (NLO) property is studied from the Kurtz-Perry method. The Second Harmonic Generation efficiency for the grown crystal 35D2HBA was 0.375 times that of the reference material KDP. As Z-Scan results provide a better transmittance, this crystal can be suggested for IR-switching applications. The sample exhibited strong antibacterial activity against K. Pneumoniae, E.Coli and S. Pneumoniae bacteria.