| Metal-organic frameworks?MOFs?have attracted the attention of researchers and become one of the popular research subjects in the realms of chemistry and materials in recent years because of their excellent properties,such as optics,electricity,magnetism and catalysis.Polyoxometalates?POMs?are regarded as one kind of outstanding inorganic building block for the design and synthesis of new POM-based MOFs with a variety of structural motifs and potential applications due to their attractive discrete,nanoscale-sized,and an unmatched range of physical and chemical properties.So the design and synthsis of POM-based MOFs?POMOFs?is one of the important parts of coordination chemistry and crystal engineering.Compared with the POMOFs built by Keggin-type and Dawson-type POM anions,it is still less than that of other building blocks,such as,{V18} and {MnMo9}.In recent years,people have successfully synthesized a large number of molecular sieve and MOFs under ionothermal conditions,but it is limited in POM-based MOFs.Many studies have shown that ionothemal synthesis is an effective way to get novel structure.Therefore,it is an effective way to design and construct multifunctional POM-based componds under ionothermal conditions.In this paper,12 new POMOFs were synthesized by hydrothermal method/ionothermal method and characterized by IR,UV-Vis,elemental analysis,XRPD and single-crystal X-ray diffraction analysis,where POM building blocks are {V18} and {MnMo9}.The electrochemical,photocatalytic,and organic catalytical properties of the related products have also been investigated in detail.The contents of this paper are divided into two chapters,as follows:Five new POMOFs 1-5 were first synthesized by ionothermal synthesis method with {V18} as building block.According to the organic ligand is divided into the following two sections:?EMIm?[{Co?en?2}4(V18O42Br)]?1??EMIm?[{Ni?en?2}3(V18O42Br)]?2??EMIm?[{Mn?en?2}3(V18O42Br)]?3?H[Cu?1,2-pn?2]4(V18O42Br)·H2O?4?[Ni?1,2-pn?3]{[Ni?1,2-pn?·H2O]0.5[Ni?1,2-pn?][Ni?1,2-pn?2]3(V18O42Br)}Br2?5?Three POMOFs 1-3 were synthesized based on ethlenediamine,vanadium,[EMIm]Br and TM?CH3COO?2?TM= Co,Ni,Mn?.Singel-crystal X-ray diffraction analysis reveals that the structure of 1 exhibits novel 3D structure,both 2 and 3 exhibit 2D structure.They were constructed by the coordination interaction between polyoxoanions(V18} and Co-en species.The energy band?Eg?of compands 1-3 is 1.69,1.62 and 1.74 eV,respectively.Compounds 1-3 have good adsorption effect on MB.The adsorption rate of compound 3 is 98%in 10 min for MB solution(30mL,3.5×10-5 mol·L-1).Compounds 1-3 exhibit good catalytic performance for the cyanosilylation.Two POMOFs 4-5 were synthesized based on 1,2-diaminopropane ligand,vanadium,and TM?CH3COO?2?TM = Cu,Ni?.Compound 4 is a porous three-dimensional framework.The energy bands?Eg?of compounds 4-5 is 1.68 and 1.75 eV respectively.In addition,compounds 4-5 have good adsorption effect for MB solution and catalytic performance for the cyanosilylation.Seven new POMOFs 6-12 were synthesized by hydrothermal method with[MnMo9O32]6-as building block.According to the organic ligand is divided into the following two sections:H4[Pr2?H2O?6?IMDc?2(MnMo9O32)]·8H2O?6?H4[Nd2?H2O?6?IMDc?2(MnMo9O32)]·8H2O?7?H4[Sm2?H2O?6?IMDc?2(MnMo9O32)]·8H2O?8?H4[La2?H2O?6?IMDc?2(MnMo9O32)]·8H2O?9?H4[Gd2?H2O?6?IMDc?2(MnMo9O32)]·8H2O?10?H3(C4N2H10)[Pr?H2O?3(MnMo9O32)]·11H2O?11?H3(C4N2H10)[Nd?H2O?3(MnMo9O32)]·11H2O?12?Five 3D chiral POMOFs 6-10 were synthesized based on 4,5-imidazoledicarboxylic acid ligand,?NH4?6MnMo9O32·9H2O and Ln?Ac?3?Ln= Pr,Nd,Sm,La,Gd?.The energy band?Eg?of compounds 6-10 is 3.4,3.5,3.3,3.4 and 3.3 eV respectively.Compounds 6-10 have good effect on photodegradation of organic dye of RhB and MB.Two new chiral POM-based rare earth metal-organic frameworks 11-12 were synthesized by hydrothermal method using piperazine ligand,?NH4?6MnMO9O32·9H2O and Ln?CH3COO?3?Ln= Pr,Nd?as the starting materials.The energy band?Eg?of compands 11-12 is all 3.5 eV.Compounds 11-12 have good effect on photodegradation of organic dye.Compounds 6-12 have good catalytic performance for the cyanosilylation.Complexes 13-19 were synthesized by hydrothermal method with compounds 6-12 and ?-Al2O3 as the starting materials and have good effect on photodegradation of organic dye MB.Photocatalytic measurements show that the decolorization rate of complex 14 can achieve 95%in 90 min for MB solution. |
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