Synthesis, Growth And Properties Of KPbBP₂O₈, Rb₄[B₄O₅(OH)₄]₂·3H₂O And H₁₂B₅NO₁₂

The work in this dissertation consists of the compound synthesis, determination of crystal structure, crystal growth and measurement of properties for KPbBP₂O₈, Rb₄[B₄O₅(OH)₄]₂·3H2O and H₁₂B₅NO₁₂. The corresponding work and results are as follows:1. Single crystals of the nonlinear optical material, KPbBP₂O₈, with dimensions of 18 mm×13 mm×6 mm were grown by the top-seeded solution growth method. The crystal structure was determined by X-ray single-crystal diffraction. X-Ray analysis revealed that KPbBP₂O₈ crystallizes in the tetragonal system with space group I 4₂d. The BO4 and PO4 groups were connected to each other alternatively via corner-sharing O atoms, to form a 12-member ring. Each adjacent 12-member ring is connected by the BO4 tetrahedra, forming the three-dimensional (3D) anionic framework, delimiting large cages in which K and Pb cations reside to ensure the cohesion of the structure, resulting in the final 3D open framework. The compound KPbBP₂O₈ has a wide transmission range from 250 to 3000 nm with the UV absorption edge at about 250 nm, the transmission is above 81% between 340-3000 nm. The powder second harmonic generation (SHG) measurements show that KPbBP₂O₈ exhibits SHG efficiency of about 0.5 times that of KH2PO4 (KDP).2. Rb₄[B₄O₅(OH)₄]₂·3H2O has been grown by slow evaporation method with crystal sizes up to 11 mm×7 mm×4 mm. Its crystal structure has been determined by single crystal X-ray diffraction and further characterized by IR, and TGA. It crystallizes in the orthorhombic space group Pbcn, with a = 16.3984(14) (A|°), b = 7.7850(7) (A|°), c = 16.0763(16) (A|°), and Z = 4. It contains isolated [B4O5(OH)4]2- polyanions, free water molecules and Rb cations. The Rb(1) and Rb(2) atoms are coordinated by nine and ten oxygen atoms, respectively. Connections between isolated [B₄O₅(OH)₄]^2- polyanions are provided by Rb+ polyhedra and the hydrogen-bonding to form a three-dimensional network. 3. H₁₂B₅NO₁₂ has been grown by slow evaporation method at room temperature with crystal sizes up to 13 mm×8 mm×4 mm. Its crystal structure has been determined by single crystal X-ray diffraction.