Synthesis, Characterization And Properties Of New Metal Borates

Borates are an important family of second-order nonlinear optical (NLO) materialswhich have been widely used in the field of photonic technologies. Generally, the B atom iscoordinated by O atoms not only in three-fold (triangular, BO3) but also in fourfoldcoordinations (tetrahedral, BO4). These triangular or tetrahedral groups can further connectto each other through common vertices to build different isolated B O clusters, which canbe used as the structural building units (SBUs) to further polymerize into infinite chains,sheets, and frameworks. Three series of borates were synthesized in this paper：Alkali-alkaline earth metal borates， main group metal borates and transition metalcomplexes borates. These new crystals are characterized by single crystal X-raydiffraction, X-ray powder diffraction, infrared spectroscopy, ultraviolet spectroscopy andthermogravimetric analyzer. We also tested the SHG efficiency of acentric structurecrystals.The first chapter is the literature review, and introduces the research progress ofalkali-alkaline earth metal borates, transition metal borates, main group metal borates, rareearth metal borates and inorganic-organic hybrid nonmetal borates.The second chapter introduces the synthetic methods, the experimental materials andexperimental apparatus.The third chapter describes six new alkali-alkaline earth metal borates which aresynthesized under hydrothermal or solvothermal conditions：LiBa1.5[B5O8(OH)3](3-1),K4Ba2[B14O20(OH)10]·3H2O (3-2), LiSr2[B10O16(OH)3](3-3), BaPb[B5O9(OH)]·H2O (3-4),Mg[B6O9(OH)2]·4H2O (3-5), LiBa[B9O15](3-6). Compounds (3-4) and (3-5) have NLOproperties. Compounds (3-1) and (3-2) have1D B-O chain structure, compounds (3-3),(3-4)and (3-5) have2D B-O layer structure, compound (3-6) has3D B-O frameworksstructure.Compound (3-5) has framework topology with the total Schl fli symbol of(32.4.53)(34.46.510.68), compound (3-6) has NbO framework topology. The SBUs of sixcompounds are different, we discussed the result of different dimensions B-Ostructure caused by different SBUs. The fourth chapter reports three new main group metal borates which aresynthesized under hydrothermal or solvothermal conditions：[NH3(CH2)2NH(CH2)2NH3][AlB5O10]·2H2O (4-1), Li7Sr[Al(B12O24)](4-2),Ba3Al2[B3O6(OH)]2[B4O7(OH)2](4-3). Compounds (4-1) and (4-3) have NLO properties.Compound (4-1) has Traditional framework structure which built up from strictlyalternating [B5O10] clusters and AlO4tetrahedra. Compound (4-2) has1D B-O chainstructure, then Connected by AlO6octahedron. Compound (4-3) is a aluminoborate whichhas double-layer structure, single layer composed of B-O-Al, two single layers connectedtogether by [B4O7(OH)2] cluster.The fifth chapter reports two new transition metal complexes borates which aresynthesized under solvothermal condition:[Zn(en)2][B8O11(OH)4](5-1),[Co(en)3]2[B4O5(OH)4]2(C2H2O4)·6H2O (5-2). Compound (5-1) has1D B-O chain structureand [Zn(en)2] complexes, the complexes and B-O chains linked together by hydrogen bond.Compound (5-2) has isolate [B4O5(OH)4] cluster and [Co(en)3], the [B4O5(OH)4] clusterand [Co(en)3] also linked together by hydrogen bond.Based on the former study of borates, we adopt hydrothermal or solvothermalconditions, change the alkali-alkaline earth metal, main group metal, transition metal andorganic ligands to make different borate structures, and research the NLO properties.