Synthesis, Growth, and Characterization of a New Thiourea and Bismuth Chloride Complex with Excellent Nonlinear Optical Properties

Abstract

Crystals of a new organometallic nonlinear optical (NLO) compound, di-μ-chloro-bis[chlorotri(thiourea)bismuth(III)]-pentachloro(thiourea)bismuth-ate(III) (DCBPB), have been successfully grown from formic acid aqueous solutions of thiourea and bismuth chloride by a slow evaporation technique. The crystal structure and atomic composition of DCBPB have been confirmed by single crystal X-ray diffraction (SCXRD), Fourier transform infrared spectra, and elemental analysis. The SCXRD results proved that DCBPB crystallizes in triclinic space group P1 with unit cell dimensions of a = 7.0606(2) Å, b = 8.8106(4) Å, c = 16.3247(8) Å, α = 99.242(4)°, β = 95.309(3)°, γ = 105.856(3)°, and Z = 2. DCBPB crystal exhibits excellent transmittance from 500 to 2500 nm and green fluorescence with maximum emission at 508 nm. The thermogravimetric-differential scanning calorimetry (TG-DSC) analysis indicates that a solid-phase reaction took place at 170.1 °C, whereas the decomposition temperature of the crystal material was 189 °C. The NLO property obtained by the Kurtz powder test showed that the second harmonic generation efficiency of DCBPB crystal is two-seventh of KDP crystal.