Synthesis And Catalytic Properties Of Carboxyquinone-Containing Ligand Complexes

The rational design and construction of novel functional coordination compounds have been one of the most intensive research topic in coordination chemistry,supramolecular chemistry,and crystallographic engineering.This is not only due to the diverse and novel topology of the coordination polymers,but also their applications in catalysis,molecular switches,gas adsorption,biomedicine,batteries and magnetism fields.It is important to synthesize coordination compounds with predictable structures and properties through the selection of reaction pathways.The properties and applications of coordination polymers are related to the choice of ligands and metal atoms.Therefore,it is very important to rationally design organic ligands,to select metal cations and to explore the reaction conditions.The idea of ligand functionalization was inspired by the important role of quinones in biological systems as photosensitizer and their rich redox properties involving processes such as single electron transfer and proton-coupled electron transfer.They have many potential applications in such fields as molecular catalysis,molecular probes and so on.Coordination polymers based on quinone ligands have been reported and their magnetic,proton conductivity and other properties have also been studied.However,their applications in photocatalytic organic transformations have been scarce.In this thesis,ligands 9,10-anthraquinone-1,4-dicarboxylic acid(1,4-H2AQDC),9,10-anthraquinone1,3-dicarboxylic acid(1,3-H2AQDC)and 9,10-phenanthrenequinone-2,7-dicarboxylic(2,7-H2PQDC)acid have been designed and synthesized.And 21 metal coordination compounds have been designed and constructed.All coordination polymers are characterized by X-ray single crystal diffraction,X-ray powder diffraction,IR spectra,thermal gravimetric analyses and their UV-visible spectra.We studied the photocatalysts for transition metal complexes synthesized with 1,4-H2AQDC as ligand.The thesis is divided into four chapters as follows:(1)In Chapter 1:The brief history of coordination chemistry and the basic concepts and application prospect of coordination compounds are simply introduced.Reviews on the research development of complexes containing of the benzene carboxylic acid and quinone compounds related with this dissertation were also brief depicted.(2)In chapter 2,the rigid ligand 9,10-anthraquinone-1,4-dicarboxylic acid(1,4H2AQDC)was designed and synthesized according to literature reports,and its structure was identified by NMR spectroscopy.We used 1,4-H2AQDC as a ligand and synthesized 14 metal complexes with different structural features.Among them,6 complexes were obtained with 1,10-phenanthroline and 4,4’-bipyridine as co-ligands.These compounds include {[Ca0.5(1,4-AQDC)0.5(H2O)]·(H2O)0.5}n(1),{[Mn(1,4AQDC)(H2O)4]·(H2O)4｝n(2),{[Co(1,4-AQDC)(H2O)3]·(H2O)2}n(3),{[Ni(1,4AQDC)(H2O)3]·(H2O)2}n(4),{[Zn 1.5(1,4-AQDC)(OH)(H2O)2]·(H2O)} n(5),{[Cu2(1,4-AQDC)2(DMF)(H2O)5]·(H2O)4}n(6),{Ag2(1,4-AQDC)(CH3OH)}n(7),{[Na0.5Zn0.5(1,4-AQDC)0.5(OH)0.5(H2O)0.5]·(H2O)0.5}n(8),[Mn0.5(1,4HAQDC)(phen)]2(9),{Co(1,4-AQDC)(phen)}n(10),{[Zn(1,4AQDC)(phen)2]·(H2O)6}n(11),{[Co0.5(1,4-HAQDC)(4,4’-bpy)0.5(H2O)]·(CH3OH)}n(12),{[Zn0.5(1,4-HAQDC)(4,4’-bpy)0.5(CH3OH)]·(CH3OH)}n(13),{[Zn(1,4AQDC)(4,4’-bpy)0.5(H2O)2]·(H2O)2}n(14).These compounds were characterized by single-crystal/powder X-ray diffraction,infrared spectra,thermal gravimertric analyses and UV-vis spectra.Among them,compound 9 comprises dimeric units,complexes 2,6,11,12,13 and 14 bear one-dimensional(1D)structures,compounds 3,4,7 and 10 are two-dimensional(2D)structures and compounds 1,5 and 8 are three-dimensional(3D)frameworks.(3)In chapter 3,the rigid ligand 9,10-anthraquinone-1,3-dicarboxylic acid(1,3H2AQDC)was designed and synthesized,and its structure was confirmed by NMR spectroscopy.Seven novel metal coordination polymers based on 1,3-H2AQDC,and divalent metal salts have been successfully synthesized,some of which have 1,10phenanthroline or 4,4’-bipyridine as auxiliary ligands.Among them,[Mg(1,3AQDC)(H2O)5·(CH3COOH)](15)exhibit monomeric structure,compounds {[Mn(1,3AQDC)(H2O)4]·H2O}2(16)and {[Ni(1,3-AQDC)(H2O)4]·(H2O)3}2(17)comporise dimeric units,{[Zn(1,3-AQDC)(H2O)4]·(H2O)}n(18),{Cu2(1,3AQDC)2(phen)(H2O)}n(19),{Co(1,3-AQDC)(4,4’-bpy)0.5(CH3OH)(H2O)2}n(20)and{Ni(1,3-AQDC)(4,4’-bpy)(CH3OH)(H2O)2}n(21)bear one-dimensional chains.These compounds were characterized by single-crystal/powder X-ray diffraction,infrared spectra and etc.(4)In chapter 4,photocatalytic properties of five transition metal complexes(3,4,5,6,7)with 1,4-H2AQDC as ligand have been studied.Both the ligand itself and its transition metal complexes are able to catalyze the visible-light driven oxidation reactions of alkynes into 1.2-di-ketones in air under mild conditions,in which compound 4 demonstrates the best activity.This catalyst can be easily isolated from the reaction mixture by filtration with trace amount of loss in solution and is ready for recycled use after simple washing and drying without any need for regeneration.Remarkably,the catalyst shows no loss of activity after five catalytic cycles and X-ray powder diffraction proves no change of structure after five runs.This designed metalorganic coordination polymer represents an environmentally friendly economic and recyclable photocatalyst,constituting a good candidate for photocatalytic organic syntheses in terms of green chemistry.(5)In chapter 5,the 9,10-phenanthrenequinone-2,7-dicarboxylic acid(2,7H2PQDC)ligand was synthesized:.Optimization of the synthesis route was done,and the nuclear magnetic resonance spectra of the some intermediates during the reaction process were identified.In addition,we have conducted a preliminary exploration of the synthesis of related complexes based on 2,7-H2PQDC.