Synthesis And Characterization Of Borates Guided By Organic Amines And Metal Complexes

Borates have attracted considerable interest because of their fascinating architectures and potential commercial applications in adsorption,separation,catalysis,especially in the field of nonlinear optical(NLO).By introducing different structure-directing agent(template),such as:inorganic cations,organic amine,transition metal complexes and so on,large numbers of borates have been synthesized and characterized.With the emergence of hydro/solvothermal synthesis method,new chance and challenge have been brought to the exploration of borates with novel structure and excellent properties.Our group aimes at the synthesis and characterization of borates by hydro/solvothermal method.Based on the previous work,we have successfully obtained a series of borate compounds by using organic amines(1,2-dap)and metal complexes as templates under mild solvothermal condition.Their structures have been determined by single crystal X-ray diffraction,and characterized by powder X–ray diffraction,thermogravimetric analysis,IR spectrum,Further characterizations of powder X-ray diffraction,UV–Vis spectroscopy.The non-centrosymmetric compounds with second-order nonlinear optical properties have been studied.These two groups are as follows:??Organic amines(1,2-dap=dap)templated borate.[H₂dap][B₃O₄(OH)₂B₃O₅](3-1)[H₂dap][B₅O₆(OH)B₂O₅](3-2)[H₂dap]₂[B₆O₁₀][B₆O₁₁B(OH)](3-3)[Hdap]₂[Al B₅O₁₀](3-4)[H₂dap][Al B₅O₁₀].H₂O(3-5)3-1?3-5 are ammonium borates.3-1 displays layer structure with 9-MR window,which uses B₃O₄(OH)₂B₃O₅{B₆-I}cluster as the fundamental building block(FBB).3-2contains a two-dimensional layer structure with 12-MR window.The FBB of 3-2 is B₅O₆(OH)B₂O₅{B₇-I}cluster.Although the presence of–OH prevents the expansion of these two structures,a three-dimensional supramolecular framework is formed via hydrogen bonds.The FBB of 3-3 is[B₆O₁₀][B₆O₁₁B(OH)]{B13}cluster which is formed by B₆O₁₂{B₆-II}cluster and B₆O₁₃BO(OH){B₇-II}cluster,further forming a three-dimensional structure with channels via O–B–O bonds.The guest molecules(1,2-dap)lacated in channels,which connect with the framework through hydrogen bonds,not only serve as template but also compensate for the negative charge that comes from oxoboron cluster.Based on the synthesis of 3-1?3-3,the Al(i-Pr O)₃ was added to the reaction system,we obtained 3-4 and 3-5.All of them use B₅O₁₀{B₅}cluster as FFB and exhibit the same connection mode.Each AlO₄ connects 11 AlO₄ through 4{B₅}clusters,and vice versa,forming an open-framework[Al B₅O₁₀]_n^2n-.The protonated 1,2-dap molecules locate in the diverse channels.??Metal complexes templated borate.1,2-dap=dap Zn(C₆N₅H₂₇)[B₅O₆(OH)₄](4-1)[Co(dap)₃][B₁₀O₁₃(OH)₆](4-2)[Ni(dap)₃][B₁₀O₁₃(OH)₆](4-3)[Co(dap)₃]₂[B₅O₇(OH)₃]Al[B₁₁O₁₇(OH)₄](4-4)[Ni(dap)₃]₂[B₅O₇(OH)₃]Al[B₁₁O₁₇(OH)₄](4-5)4-1 is an isolated pentaborate which uses Zn(C₆N₅H₂₇)as template.4-2 and 4-3 are isolated isomorphism compounds which tempaleted by M(dap)₃(M=Co,Ni).The isolated cluster:B₁₀O₁₃(OH)₆{B₁₀}is discovered for the fisrt time and fill the gap left by the absence of isolated structures in the borate family.4-4 and 4-5 are isolated isomorphism compounds with two different oxoborn clusters:[B₅O₇(OH)₂][B₅O₈(OH)BO₂(OH)]{B₁₁}cluster and[B₅O₇(OH)₃]cluster.These two isolated clusters are connected by AlO₄.The{B₁₁}clusters and AlO₄alternately connecte to form a thick layer with 19-MR window,forming three-dimensional supramolecular structure via hydrogen bonds.Noticed that three kinds of bridging mode of{B₅}clusters are displayed in 4-4 and 4-5.The second-order nonlinear optical properties of the non-centrosymmetric compounds 4-4 and 4-5 are studied.The SGH response are 1,3?and 0.9 times of KDP respectively.The UV cut-off edge of 4-5is below 200nm indicating that it is a deep UV NLO materal,while 4-4 is a UV NLO materal.