Syntheses, Structures And Properties Of A Series Coordination Polymers Based On The Di/tris-(tetrazol-5-yl)benzene

The5-substituted tetrazolate-based coordination polymers haveattracted a great deal of attention in recent years, mainly becausetetrazolates are unique for their highest number of N-donors andversatile coordination modes. They have been utilized to generate alarge variety of functional metrials with diversiform structures.Sharpless et al. reported that high-yielding5-substituted tetrazolescan be prepared very conveniently by the [3+2] cycloaddition reaction.This dissertation mainly focuses on the hydro(solvo)thermalsyntheses, structures and properties of series of coordinationcomplexes based on5,5’-(1,4-phenylene)bis(1H-tetra-zole)(H2BDT)and1,3,5-tris(tetrazol-5-yl)benzene(H3BTT) from [3+2] cycloadditionreactions. The thesis is divided into four chapters. The main contentsare summarized as below：In the first chapter, the research background is conciselyintroduced by illustrating recent advances on metal-organiccomplexes and mainly on synthesizing methods. In addition, summary of research progresses on the syntheses, structures, properties andapplications of polytetrazolate complexes in the past few decades,are presented. Finally, the aims and advances of this work are alsooutlined.The second chapter, a series of four coordination complexes:Cd(BDT)(H2O)4(1), Cd4(H0.667BDT)6·4H2O (2), Mn(BDT)(2,2’-bpy)(3)，Co3(ox)(H0.67BDT)3(H2O)·4DMA·4H2O (4) have been achieved byhydrothermal synthesis from5,5’-(1,4-phenylene)bis(1H-tetra-zole)(H2BDT) ligand with different metal salts, in which the ligand wassynthesized by [3+2] cycloaddition previously. Complex1is a1Dchain polymer from CdN2O4octahedron and BDT2-. Compound2and3contain similar {M(tetrazolate)}n chain connected by terminal μ4-BDT2-via the N2and N3atoms, the more common binding mode. The3Dporous MOF of2with1D triangle channel is constructed from theZig-Zag chain [Cd(ttz)]nbased on the N2and N3atoms of tetrazolebridged by terminal and crossover side-on μ4-BDT2-.3is also a3Dporous framework cross linked by the [Mn(ttz)]nchains, but auxiliarycoordinated2,2’-bpy occupied in the channel. Compound4exists alinear trinuclear [Co3(ttz)6] unit. Adjacent trinuclear [Co3(ttz)6] unitsare linked by ox2bridges into1D [Co3(ttz)6(ox)]nchains. And then the[Co3(ttz)6(ox)]nchains are extended by BDT2-ligands into aninteresting3D MOF structure with1D triangular channels along the c-axis and1D square channels along the a-axis. And adsorptionexperiment shows selectivity adsorption for H2and O2over CO2,possibly because of the preferential adsorption of moleculardynamics with small radius.In chapter3, firstly,1,3,5-tris(tetrazol-5-yl)benzene(H3BTT) wassynthesized by the reaction of [3+2] cycloaddition. Then two newcompounds，namely, Zn6(BTT)(OH)3(CO3)3(5), Cu3(Cu4O)3(BTT)8(H2O)12(6) obtained by solvo(hydro)thermal reactions. Compound5,crystallizing in the noncentrosymmetric space group, is a3Dloop-shaped MOF constructed from Zn ions linked by μ5-CO23-andμ3-OH with the coordinated μ6-BTT occupied in the channel.The SHGefficiency is about1.4times that of KDP and is phase-matchable,which could be a potential functional material for nonlinear opticalapplications. Compound6is a cubic structure in whichoxygen-centered square-planar [Cu4O]6+units are linked via BTT3-ligands to form the anionic, three-dimensional framework. The N2andN3atoms of two tetrazolate rings on individual BTT3-ligands bridgepairs of Cu2+ions along the edges of a square, such that each [Cu4O]6+moiety is surrounded by eight BTT3-ligands. In turn, each BTT3-ligandconnects three [Cu4O]6+units so that, overall, six squares and eightplanar BTT3-ligands define the faces of a truncated octahedron,reminiscent of a sodalite cage. Each cage shares its square faces with six neighboring cages, defining a network structure closelyrelated to that of sodalite. And the high adsorption for N2and O2molecules possibly owned to coordinatively unsaturated metal sites.The nitrogen and oxygen sorption isotherms display remarkablehysteresis between adsorption and desorption curves at77K. Thehysteretic desorption may indicates strong interaction between gasmolecules and host frameworks.In the last chapter, a concise conclusion was drawn and an outlookof this work was expected.