Synthesis,Structures And Properties Of Metal Borates Under Solvothermal Condition

Borates are of considerable interest because of their potential applications,such as nonlinear optics.In addition,inorganic microporous borate compounds are also important class of molecular sieve materials.These microporous materials not only have the characteristics of conventional zeolite materials,but also have the nonlinear optical properties of borate compounds.In the borate compounds,boron can generally take two coordination configuration:BO3(?)plane triangular and BO4(T)tetrahedron.And these BO3 triangles and BO4 tetrahedra can further link together via common oxygen atoms to form one-dimensional chain-like,two-dimensional layered,and three-dimensional network skeleton.The common synthetic methods of borate compounds have high temperature solid phase,boric-acid flux method and hydro/solve thermal method.In this paper,PEG-400as solvent to synthesis main group metal borates.In this paper,six novel main group metal borate compounds were synthe-sized under the solvothermal conditions.Which includes four alkali metal bor-ate compounds:Na2B9O15(H20)(H30)(1),NaB8O12(OH)2·0.5(H2OCH2CH2OH2)(2),Li3(B17O30H4)(CH3CH2NH3)2·2H20(3),K2B12O18(OH)2(NH2CH2CH2CH2NH2)2·H2O(4)and two aluminum boratecompounds:[Zn(N2H4)(H2O)3][AlB5O10](5),KAl(B5O10H)(BO3H2)(CH3NH3)(6).The structures and properties of thesemater ials were characterized by X-ray single crystal diffractometer,X-ray powderdif fraction,infrared absorption spectroscopy,thermogravimetric analysis,UV-visibl e diffuse reflectance spectroscopy and second harmonic generation(SHG)meas urement.Na2B9O15(H2O)(H3O)(1)crystallizes in the monoclinic space group P21,which have large 13-ring channels of boron oxide framework is constructed from different cluster units of B3O7 and B6O13.Compound 1 display a moderate secondharmonic generation(SHG)response comparable to that of KH2PO4(KDP).NaB8O12(OH)2·0.5(H2OCH2CH2OH2)(2)crystallizes in the monoclinic space groupP21/c,which consists of B3O6(OH)clusters and B5O9(OH)clusters bonded through B-O-B bonds to form a two-dimensional layered anion skeleton.The glycol molecules are located between the layers and layers,and play a role in charge balance and structural stability.Li3(B17O30H4)(CH3CH2NH3)2·2H2O(3)crystallizes in the monoclinic space groupC2/c,which have a large cluster of B12O16(OH)4 formed by four interconnected B3O5(OH)clusters.B12O16(OH)4cluster and B5O10 clusters are connected in turn to formea one-dimensional chain anion structure withoctahedral cage;lithium ions are lacate in the cage,supporting the cage structure.K2B12O18(OH)2(NH2CH2CH2CH2NH2)2·H2O(4)crystallizes in the monoclinic space groupP21/c,which is a two-dimensional layered anion structure formed by the interconnection of B6O11(OH)clusters through common oxygen atoms;1,3-Diaminoethanemolecules are alternately suspended on both sides of the layerthrough the B-N bond,and potassium ions and water molecules are located between the layers.[Zn(N2H4)(H2O)3][AlB5O10](5)crystallizes in the orthorhombic space groupC2221,which is mainly composed of AlB5O10 cluster,and Zn(N2H4)(H2O)3 complex as template.In the anionic network structure,this template with the formation of ammonia and Zn coordination has not been reported;Compound 5 has a noncentrosymmetric space group.KAl(B5O10H)(BO3H2)(CH3NH3)(6)rystallizes in the triclinic space group P-1.In the structure,an AlO4 tetrahedron connecting three B5O9(OH)clusters and one BO3H2 cluster,one B5O9(OH)connecting three AlO4 tetrahedron,through this connection to form a one-dimensional chain anion structure.Free potassium ions and protonated methylamine are located between the chain and the chain,can make the charge balance and structural stability.