| Metal organic framework(MOF)is a kind of porous organic-inorganic hybrid crystalline material formed by the self-assembly of coordination bonds between metal ions or clusters and organic ligands.MOF has the advantages of high porosity,large specific surface area,easy tuning of optical and electronic structures,etc.,which has promoted unprecedented exploration in the field of photoluminescence.Luminescence in MOF can be achieved by using luminescent connectors,metal clusters or rare earth elements,or through guest inclusions mediated by various antenna effects.Suitable MOF design can make it the best material in the fields of white light emission,LED,luminous thermometer and so on.This article uses carboxylic acid ligand 5-((3S)-3-carboxy-2,2,3-trimethylcyclopentane-1-carboxamide)isophthalic acid(H3L1),nitrogen-containing ligand 1,3,5-Tris(imidazol-1-ylmethyl)benzene(TIMB),1-(1-imidazolyl)-3,5-bis(imidazol-1-ylmethyl)benzene(IBIMB)and 4-(4-(1H-imidazol-1-yl)phenyl)-4H-1,2,4-triazole(ITB),self-assembled with lanthanide metal ions and transition metal ions to synthesize a series of complexes,[Ln2(L1)2(DMF)3](1-11)(Sm,Eu,Gd,Tb,Dy,Er,Tm,Yb,Y?Yb0.2Tb0.8?Yb0.5Tb0.5),{[Zn3(?2-OH)2(TIMB)(BDC)2]·0.25H2O)n(XXQ-1),{[Zn2(IBIMB)(BDC)2(H2O)]·5H2O}n(XXQ-2),[Co(ITB)(1,4-BDC)](12),{[Zn(ITB)(1,4-BDC)(HCOOH)]·H2O}n(13),[Zn(ITB)(1,3-BDC)(H2O)(14),[Cu(ITB)(1,4-BDC)](15),[Cu(ITB)(2-NO2-BDC)](16),[Zn(ITB)(1,4-BDC)](17)(BDC=1,4-benzenedicarboxylate).Complexes 1-11 have the same structural unit and have a two-dimensional structure.Fluorescence measurements show that the complexes1,2,4 and 5 have good down-conversion solid-state luminescence properties.The characteristic emission of Sm3+,Eu3+,Tb3+and Dy3+is shown.The upconversion luminescence properties of lanthanide complexes co-doped with Yb3+and Tb3+were also studied.With the increase of Yb3+doping concentration,the luminescence intensity of complexes 10 and 11increased gradually,and the mechanical properties of complexes 4.The complexes XXQ-1 and XXQ-2 have three-dimensional structures.XXQ-1 has a(3,7)-connected network with the dot symbol(3·4·5)(32·42·5·613·73),while the complex XXQ-2 has a(3,3,4)-connected network with the dot symbol(4·6·83·10)(4·6·8)(6·82).XXQ-2 has better electrical conductivity than XXQ-1,which may be due to the higher rigidity of IBIMB,which is beneficial to electron charge transfer.Complexes 12-17 are based on multiple coordination complexes of imidazole with triazole ligands and auxiliary ligands phthalic acid and derivatives.Complex 12 is a staggered two-dimensional structure.Complexes 13-14 are all one-dimensional chains,but the difference is that complexes 13 are coordinated by formic acid molecules,while complexes14 are coordinated by water molecules.Both complex 15 and complex 16have 2D structure.Complex 15 forms the sequential stacking of ABAB,while complex 16 forms the sequential stacking of AAA.Strong photoluminescence was observed in both complexes 13 and 17. |
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