Synthesis,Structures And Luminescent Properties Of Lanthanide/lanthanide-transition Metal Coordination Complexes

Lanthanide/lanthanide-transition metal coordination complexes not only have attractive structures,but also become a research hotspot because of their potential applications in the fields of single-molecule magnets and low-temperature thermometers.In the past ten years,most of the lanthanide/lanthanide-transition metal coordination complexes were synthesized by hydrothermal/solvothermal methods.we synthesized four lanthanide metal coordination polymers（compounds 1-4）,two zero-dimensional lanthanide-transition metal clusters（compounds 5 and 6）,and two cases of zero-dimensional lanthanide-transition metal complexes（compounds 7 and 8）under hydrothermal conditions.A 2D lanthanide metal coordination polymer,namely[Ho₂（C₄O₅H₄）₃（H₂O）₄]·2H₂O（1）,hydrothermal synthesis from rare earth metals Ho and 2,2’-oxybisaceticacid（C₄O₅H₆）ligand.Compound 1 crystallizes in the orthorhombic space group C222₁.This compound is a 2D layered structure by lanthanide Ho ion interconnecting with the carboxyl oxygen atom on the 2,2’-oxybisaceticacid ligand.A 3D lanthanide metal coordination polymer,namely Gd₂(C₁₄O₅H₈)₃（H₂O）₄（2）,hydrothermal synthesis from rare earth metals Gd and 4,4’-Diphenyl ethyl dicarboxylic acid(C₁₄O₅H₁₀)ligand.Compound 1 crystallizes in the monoclinic space group P2₁/c.The lanthanide Gd ion in the compound is connected to the oxygen atom on the 4,4’-Diphenyl ethyl dicarboxylic acid ligand to form a 2D layer,and the layer is connected through the ligand oxygen atom to form a 3D skeleton structure.A 3D lanthanide metal coordination polymer,namely[Dy2（ida）3]·H2O（3）,hydrothermal synthesis from rare earth metals Dy and Iminodiacetic acid（H₂ida）ligand.Compound 3 belongs to the tetragonal crystal system,the space group is I41/a.The lanthanide Dy ion in the compound is connected to the oxygen atom on theIminodiacetic acid ligand to form a 2D layer,and the layer is connected through the ligand oxygen atom to form a 3D network structure.A 3D lanthanide metal coordination polymer,namely[Ho₂（2,3-pzda）₃（H₂O）₅]·3H₂O（4）,hydrothermal synthesis from rare earth metals Ho and 2,3-Pyrazinedicarboxylic acid（2,3-pzdaH2）ligand.Compound 4 belongs to the triclinic system and the space group is P-1.The lanthanide Ho ion in the compound is connected to the oxygen atom on theIminodiacetic acid ligand to form a 2D layer,and the layer is connected through the ligand oxygen atom to form a 3D network structure.The use of 2-Hydroxy-2,2-diphenylacetic acid(C₁₄O₃H₁₂),Titanium（IV）oxysulfate dihydrate and rare earth nitrates has led two zero-dimensional lanthanide-transition metal clusters[LnTi（μ₃-O）(C₁₄O₃H₁₀)₃（H₂O）₄]·H₃O[Ln=Eu（5）,Tb（6）].Compounds 5 and 6belong to the monoclinic system,space group C2/c.Rare earth ions and titanium ions are linked by twoμ_3-O ions to form a tetra-nuclear[Ln₂Ti₂（μ₃-O）₂]cluster core,tetra-nuclear[Ln2Ti2（μ3-O）2]cluster core is surrounded by six 2-Hydroxy-2,2-diphenylacetic acid ligands.Aspects of the fluorescence properties and fluorescence-temperature response of compounds 5 and 6 are discussed.We synthesize two zero-dimensional lanthanide-transition metal coordination complexes Ln₂Ti₂(C₁₄O₃H₁₀)₆（C₄O₅H₄）₂（H₃O）₂[Ln=Eu（7）,Tb（8）],by employing the2,2’-oxybisaceticacid,2-Hydroxy-2,2-diphenylacetic acid,Titanium（IV）oxysulfate dihydrate and rare earth nitrates.Compounds 7 and 8 belong to the monoclinic system,space group P21/c.Rare earth ions and titanium ions are linked by ligand to form a tetra-nuclear[Ln₂Ti₂]coordination complexes,Compound 7 was tested for fluorescent properties.