| Polyoxometalates(POMs)have abundant structure and excellent physical and chemical properties,which make them have a broad application prospects in the hot fields of catalysis,medicine and proton conduction,and so on.In recent years,the combination of POMs and coordination polymers has been a hot field in the research of POMs-chemistry.POMs-based coordination polymers combine the advantages of POMs and coordination polymers,which make them possible to construct functional complexes with original structures and predominant performance.In this paper,different nitrogen heterocyclic ligands and transition metal ions were selected and modified by various types of POMs.Through continuous improvement of reaction conditions,fourteen novel POMs-based coordination polymers have been obtained successfully and characterized by X-ray single crystal diffraction,X-ray powder diffraction,infrared spectroscopy,elemetal analysis and thermogravimetric analysis.The electrochemistry,magnetism,photocatalysis and proton conduction of some compounds have been measured.The main contents in this thesis are as follows(1)Based on 4,4’-bis(4H-1,2,4-triazol-4-yl)diphenyl(btdp),1,3-bis(4H-1,2,4-triazol-4-yl)benzene(btb)nitrogen heterocyclic ligands and Keggin-polyacid anions,six novel coordination polymers have been successfully obtained,respectively:[M3(PW12O40)2(btdp)6]n(M=Co(1),Zn(2)),{[Cu3(btdp)3(OH)(PW12O40)(H2O)4]·8H2O}n(3),{[Fe2(btb)3Cl(H2O)(XO40)]·4H2O}n(4),{[Fe2(btb)3(H2O)2(XO40)]·3H2O}n(5),{[Fe2(btb)3Cl(H2O)(XO40)]·2H2O}n(6)(X=PW12(4),SiW12(5),PMo12(6)).Compounds 1 and 2 are isomorphous,which exhibit a rare diamond network structure with six-fold penetration.There are three different copper ions in compound 3,the metal ions are bridged by the btdp ligands to form 1D chains,which coordinate with polyacid anions to form the 2D layers,and further extended to the 3D structure by hydrogen bonding interactions.Compounds 4-6 have the same configuration,the Fe1 and Fe2 ions are coordinated with the terminal oxygen atoms of the polyacid anions and the nitrogen atoms of the btb ligands to form 2D layer,and further extends to 3D framework structures through multiple hydrogen bonding interactions.The properties of compounds 1-6 were tested.Compounds 1,2 and 4 have good ability to confront acid and alkali,compounds 3 and 5 have good stability in water.Compound 1 exhibits certain photocatalytic degradation effect on Rhodamine B organic dye,the degradation rate is up to 66.81%after 2.5 h in the light.Compounds 1,4 and 5 exhibit antiferromagnetic behaviors,Compound 3 exhibits paramagnetic behavior.Furthermore,at 85℃ and relative humidity of 98%,the proton conductivity of compounds 1,2,4 and 5 are up to the best,which respectively is 2.72×10-5 S cm-1,5.53×10-5 S cm-1,3.21×10-4 S cm-1 and 6.53×10-5 S cm-1,showing definite proton conductivity.(2)Based on 3,5-bis(imidazol-1-yl)-5-(benzimidazol-2-yl)benzene nitrogen heterocyclic ligands(bibb),four novel coordination polymers have been obtained through continuous improvement of reaction conditions,respectively:[M(H2bibb)2(H2O)3(α-P2W18O62)]·nH2O(M=Ni(7),Co(8),Cu(9)),[Zn(Hbibb)2(H2O)](α-P2W18O62)(H2bibb),5H2O(10).Compounds 7-9 have the same configuration,the metal ions are coordinated with the[α-P2W18O62]6-anions,water molecules and ligands to from mononuclear structure[M(H2bibb)2(P2W18O62)(H2O)3],and further expand to 2D layered structure by N-H...O hydrogen bonding interactions,the 3D framework is constructed by various C-H...O hydrogen bonding interactions.In compound 10,two metal ions are bridged by the ligands to form a metal organic ring {Zn2(H2bibb)4},[α-P2W18O62]6-anions are in free state,the 2D layers are constructed between[α-P2W18062]6-and ligands by N-H...O hydrogen bonding interactions,and further expand to 3D framework by C-H...O hydrogen bonding interactions.The properties of compound 7-10 were tested.Compounds 7-9 have good stability in water.Compounds 7-10 show definite proton conductivity.At 85℃ and relative humidity of 98%,the proton conductivity of compounds 7,9 and 11 are up to the best,which respectively is 5.94×10-5 S cm-1,1.57×10-5 S cm-1 and 3.68×10-5 S cm-1,at 65℃ and relative humidity of 98%,the proton conductivity of compound 8 is 2.23×10-5 S cm-1.Compound 7 exhibits certain photocatalytic degradation effect on Rhodamine B organic dye,the degradation rate is up to 55.01%after 2.5 h in the light.(3)Based on 3,5-bis(1-imidazole)pyridine(bip),1,3-bis(4H-1,2,4-triazol-4-yl)benzene(btb),1,3,5-(1-imidazolyl)benzene(tib)nitrogen heterocyclic ligands,four new coordination polymers have been successfully obtained,respectively:{[Co(Hbip)2(H2O)2(Mo8O26)]·3H2O}n(11),[Co2(btb)2(H2O)2(Mo8O26)]n(12),[Cu(tib)2(W6019)]n(13),[Ni(Htib)(H2O)3(H2W12O40)0.5·3H2O]n(14).In compound 11,polyacid anions[Mo8O26]4-are alternate connection with[Co(Hbip)2·2H2O]4+to form 1D chains,and the 1D chains are further extended to the 2D layers by the Mo-N bonds between the[Mo8O26]4-anions and btb ligands.In compound 12,polyacid anions[Mo8O26]4-are alternate connection with {Co2(btb)2} to form 2D layers,and further extended to the 3D structures by the connection of btb ligands.In compound 13,the metal ions are bridged by the tib ligands to form 3D frame structures,and the polyacid anions[W6O19]2-are filled in the cavity by electrostatic interaction.In compound 14,metal organic ring {Ni2(Htib)2} are alternate connection with[H2W12O40]6-to form 1D chains,and further extended to the 2D layers by N-H...O hydrogen bonding interactions,and further expand to 3D framework by C-H...O hydrogen bonding interactions.Compounds 11,12 and 14 have good stability in water.At 85℃ and relative humidity of 98%,the proton conductivity of compounds 11,12 and 14 are up to the best,which respectively is 1.51×10-3 S cm-1,1.34×10-5 S cm-1 and 2.35×10-5 S cm-1,Compound 11 shows good proton conductivity,and compounds 12 and 14 show definite proton conductivity.Compound 12 exhibits certain photocatalytic degradation effect on Rhodamine B organic dye,the degradation rate is up to 69.41%after 2.5 h in the light.Compound 12 is metamagnet,which exhibits antiferromagnetic and ferromagnetic behaviors.Compound 14 exhibits antiferromagnetic behaviors. |
