| The focus of the research in the field of modern coordination chemistry is to design and construct the coordination polymers with novel structures and excellent functions.Related research scholars have been committed to this research topic for several years and turned their attention from synthesis to functionalization gradually.Coordination polymers are self-assembled by metal nodes and organic linkers.Therefore,metal ions/metal clusters and organic ligands play a decisive role in the structure of coordination polymers.Nowadays,more and more organic ligands have been widely used.In order to obtain more coordination polymers with novel structures,the in situ ligand formation reactions provide new possibilities for this.Inspired by this,in this thesis,by employing the hydrothermal in situ acylation of organic polycarboxylic acids with N2H4,7 examples of acylhydrazidate-based coordination polymers were constructed.In addition,we also select two new semi-rigid hexacarboxylic acid molecules as organic ligands,synthesizing 2 cases of polycarboxylate-based coordination polymers under solvothermal conditions.And the single crystal structure analysis and performance study of 9 compounds were carried out.This paper is divided into five chapters:Introduction is presented in the first chapter,which briefly introduces the concept,development history,classification and wide application in related fields of coordination polymers.The classification part focuses on the importance of organic ligands during the synthesis of coordination polymers,which introduces in situ synthesis reactions.Finally,it briefly lists the topics,significance,main research results,synthesis methods,testing instruments and experimental reagents of the selected topics in this thesis.In the second chapter,by employing the in situ acylation of organic acid with N2H4,twoacylhydrazinotetracarboxylate-basedcoordinationpolymers[Cd2(HL1)(phen)2(H2O)]·4.5H2O(1)and[Mn2(HL1)(phen)2]·7H2O(2)(H5L1=5,5'-(1,4-dioxo-1,2,3,4-tetrahydrophthalazine-6,7-diyl)-di-(oxy)diisophthalic acid,phen=1,10-phenanthroline)were obtained.1 and 2 both possess 1D structures.Both the auxiliary ligand phen and the uncoordinated acylhydrazine ring will prevent 1 and 2from forming dense networks.Fluorescence tests show that 1 and 2 both emit yellow light(originate from the large excitation wavelengths),corresponding to the charge transfer from?*anti-bonding orbitals of benzene ring moiety to?bonding orbitals of acylhydrazine ring moiety.Based on this,we investigated their sensing properties towards 2,4,6-trinitrophenol(TNP).It is turned out that 1 is not an ideal sensor,but 2can be considered as an excellent sensor for the detection of TNP.The difference of structure between 1 and 2 results in the difference of dispersant,then influence the light absorption capabilities of TNP.In addition,the energy of lowest unoccupied molecular orbitals(LUMOs)of ligand in the material may be also affected.These factors ultimately lead to the difference in the sensing results of the two compounds.In the third chapter,by employing the in situ acylation of organic acid with N2H4,five examples of diacylhydrazidate-based coordination polymers[Zn(L2)(2,2'-bpy)](3),[Cd(L2)(phen)(H2O)](4),[Pb(L2)(phen)](5),[Cd3(L3)3(H2O)4(N2H4)]·3H2O(6)and[Pb(L3)(4,4'-bpy)](7)(H2L2=6,6'-(2,2-diperfluoropropanyl)bis(2,3-dihydro-phthalazine-1,4-dione),H2L3=6,6'-sulfonyl bis(2,3-dihydrophthalazine-1,4-dione),phen=1,10-phenanthroline,2,2'-bpy=2,2'-bipyridine,4,4'-bpy=4,4'-bipyridine)were obtained.3,4,and 6 all present 1D chained structures,while 5 and 7 present 3D network and 2D layered structure,respectively.It is worth noting that the auxiliary ligand directly affects the final structure of these compounds.Fluorescence test showed that oligomers 3,4,and 6 all emit light,while 5 and 7 do not emit light.Since the light emission of the three compounds all originate from the larger excitation wavelength,we explored their chemical sensing properties.The results show that:(i)all three compounds can sense acetylacetone;(ii)3 can detect TNP in Et OH,while 4 can recognize TNP in Me OH;(iii)6 can stably exist in aqueous solutions with p H=3?11,but in a strong acid or a strong alkaline solution,the fluorescence is quenched due to the collapse of the framework.In the fourth chapter,under solvothermal conditions,two examples of polycarboxylate-basedcoordinationpolymers[(CH3)2NH2][Zn3(L4)(OH)(H2O)2]]·2DMF·0.5H2O(8)and[(CH3)2NH2]2[Cd2(L5)]·3DMA·2H2O(9)(H6L4=5,5'-(4,5-dicarboxyl-1,2-phenylene)-dioxo-diisophthalic acid,H6L5=5,5',5''-(benzene-1,3,5-triyltri(oxy))triisophthalic acid)were synthesized.Both compounds possess 3D porous anion frameworks,and[(CH3)2NH2]+exists in the pores.Rare earth ions are introduced by cation exchange method to obtain Eu0.6Tb0.4@8 and Eu0.6Tb0.4@9.Fluorescence test shows that both 8 and 9 emit blue light,and Eu3+and Tb3+are sensitized by organic ligands,emitting characteristic red light and green light respectively.By designing an appropriate molar ratio of Eu3+and Tb3+and adjusting the excitation wavelength of the composite material,it is finally found that Eu0.6Tb0.4@8 and Eu0.6Tb0.4@9 are not only the fluorescent photochromic materials but also the potential white-light emitting materials.In the fifth chapter,the work during the master's degree is mainly summarized and the future research direction of our research group is looked forward to. |
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