Characterization, NLO and theoretical studies of thallium hydrogen phthalate Available to Purchase

Single crystals of thallium (I) hydrogen phthalate (THP; TlC₈H₅O₄) were grown from an aqueous solution containing equimolar quantities of potassium hydrogen phthalate (KHP; KC₈H₅O₄) and thallium (I) sulfate (Tl₂SO₄) through the slow-evaporation solution growth technique. The crystal structure of THP was determined through single-crystal X-ray analysis. The THP complex is an orthorhombic system with non-centrosymmetric space group Pca2₁. Seven-coordinated thallium in a distorted pentagonal bipyramid was observed. The powder X-ray diffraction pattern revealed the crystallinity of the as-grown specimen. The bandgap energy was estimated using diffuse reflectance data by the application of the Kubelka–Munk algorithm. The functional groups were identified by Fourier transform infrared spectral analysis. The scanning electron microscopy study revealed the surface morphology of the grown crystal. Density functional theory (DFT) at the Becke three-parameter Lee–Yang–Parr level with the LanL2DZ basis set was used to derive the optimized geometry, dipole moment and polarizability. Hirshfeld surfaces, derived using single-crystal X-ray diffraction data, revealed that the close contacts are associated with strong interactions. Fingerprint plots were used to locate and analyze the percentage of hydrogen (H)-bonding interactions. The nonlinear optical (NLO) response is confirmed by the Kurtz and Perry technique gave the result that the efficiency of the complex is ∼0·6 times that of KHP.