Synthesis And Properties Of Cycloiridium Metal Complex-functionalized MOFs

Metal-organic frameworks(MOFs),which also known as porous coordination polymers or PCPs,are an emerging class of porous materials.They are constructed by self-assembly of single metal cation(primary building unit(PBU))or metal cluster(secondary building unit(SBU))and organic ligands with multiple binding sites,forming one-dimensional,two-dimensional or three-dimensional extended coordination networks.MOFs have potential applications in many fields due to their unique characteristics,such as highly diverse structure,large surface area and adjustable pore size.Electrogenerated chemiluminescence(ECL),is a kind of light radiation produced by chemical reaction between electrode reaction products or between electrode reaction products and a certain component in solution when a certain voltage is applied on the electrode.With the advantages of high sensitivity,low background and wide linear range,ECL analysis has been widely used in cancer diagnosis,biosensor,DNA detection,clinical application,food and water safety detection,trace detection of explosives,fingerprinting and so on.Ru(bpy)32+ derivatives and cyclometalated iridium(?)complexes are the most commonly used ECL luminescent groups.At present,the commonly used MOFs-ECL system is Ru(bpy)32+and its derivatives ECL system.The design and synthesis of the MOFs-ECL system with high ECL properties,stable luminescence and controllable structure is an important content of ECL research.In the thesis,the synthesis and performance of functionalized MOFs were proposed.The zirconium based MOFs with controllable structure by changing the synthesis conditions.Based on encapsulation and coordination interaction between MOFs and cyclometalated iridium(?)complexes,the functionalized MOFs with ECL properties were formed by combining with cyclometalated iridium(?)complexes([(bt)2Ir(?-Cl)]2,[(dfppy)2Ir(?-Cl)]2,[(ppy)2Ir(?-Cl)]2,and[(3-pba)2Ir(?-Cl)]2).The effects of synthesis conditions on the morphology,optical and ECL properties of the functionalized MOFs were studied.The thesis is composed of three parts:introduction,research report,conclusion and prospect.This major contents consists of two parts:general introduction and research contents.The first part is the introduction.The reaction mechanism and system classification of ECL were introduced briefly.The metal organic frameworks and their classification were summarized.Then the research progress of metal organic frameworks with ECL behaviors was reviewed in details,and finally purpose and contents of the thesis were expounded.The second part is the research contents,which consists of the following three parts.First chapter,synthesis and properties of UiO-67 and its functionalized UiO-67 with[(bt)2Ir(?-Cl)]2.Seven kinds of zirconium based MOFs composed of 2,2'-bipyridine-5,5'-dicarboxylic acid(bpydc)linkers and zirconium clusters were synthesized by four methods.The shape and structure were studied.Furthermore,four kinds of UiO-67-(1-4)with good structure were selected as carrers to synthesize functionalized UiO-67-(1-4)bt with[(bt)2Ir(?-Cl)]2.The specific surface area,thermal stability,optical and other properties and ECL performances were also studied.It was found that UiO-67-4-Ir synthesized by adding acetic acid and reacting for 12 h has good ECL behaviors in dichloromethane.Second chapter,synthesis and properties of different cyclometalated iridium(?)complexes functionalized UiO-67.Based on the synthetic method of UiO-67-4,UiO-675 was synthesized by shortening the reaction time.Four different functionalized UiO-67Ir(UiO-67-5-bt,UiO-67-5-dfppy,UiO-67-5-ppy and UiO-67-5-(3-pba))with cyclometalated iridium(?)complexes([(bt)2Ir(?-Cl)]2,[(dfppy)2Ir(?-Cl)]2,[(ppy)2Ir(?Cl)]2 and[(3-pba)2Ir(?-Cl)]2)were synthesized by the "two-step”method.Their morphology and structure,specific surface areas,thermal stability,optical,ECL behaviors and the interaction were studied.It was found that the interaction between MOFs and cyclometalated iridium(?)complexes included encapsulation and coordination interaction.And the functionalized UiO-67-5-bt and UiO-67-5-dfppy with[(bt)2Ir(?-Cl)]2 and[(dfppy)2Ir(?-Cl)]2 apprently had good ECL behaviors.Third chapter,synthesis and properties of functionalized bio-MOF with different iridium complexes.A kind of biological MOF(bio-MOF)was synthesized,which contained 2,2'-bipyridine-5,5'-dicarboxylic acid(bpydc)linker.The functionalized bioMOF was introduced[(bt)2Ir(?-Cl)]2 and[(dfppy)2Ir(?-Cl)]2,which can produce better ECL signals.The effects of different synthesis methods on the morphology and structure,optical and ECL behaviors of the functionalized bio-MOF were studied.Two kinds of bio-MOF(bio-MOF-bt-1 and bio-MOF-dfppy)were synthesized by the"two-step"method,and bio-MOF-2 was synthesized by the "one-step" method.It was found that the bio-MOF-bt-2 synthesized by the "one-step" method had a better ECL behavior in aqueous phase.The third part is the conclusion and prospect.In this part,the research results was summarized and analyzed,and the future work was prospected.In the thesis,a series of functionalized MOFs with cyclometalated iridium(?)complexes were synthesized by using two different MOFs materials containing 2,2'bipyridine-5,5'-dicarboxylic acid(bpydc)linkers and four different cyclometalated iridium(?)complexes.The effects of synthesis conditions on the morphology,optical and other properties and ECL performances of the functionalized MOFs were studied.Eleven kinds of functionalized MOFs with certain morphology and ECL behaviors were obtained.The thesis provides a certain experimental basis for the synthesis of functionalized MOFs with good ECL properties and controllable morphology based on the encapsulation and coordination interaction.