| Coordination compounds have attracted considerable attention due to their intriguing structures and wide potential applications in molecular magnetism,luminescence,gas storage and separation,etc.Although lots of compounds has been made,the controllable synthesis of coordination compounds with unique structure and function still remains a long-term challenge because their self-assembly processes are often influenced by some factors.The derivatives of pyridine carboxylic acid containing carboxyl groups and nitrogen atoms have been widely used to construct coordination compounds due to their wide range of binding modes.In this paper,thirteen coordination compounds based on3-?3-carboxylphenyl?-6-carboxylpyridine?H2cppca?have been design and synthesis at room temperature under hydrothermal/solvothermal conditions.All the compounds were fully characterized by IR spectroscopy,thermal analysis and single-crystal X-ray diffraction.Moreover,magnetic,fluorescence properties and adsorption performance of the complexes have also been studied and applied.The main contents are as follows:1.Six new coordination compounds based on H2 cppca,{Ni?cppca??H2O?4·2H2O}n?1?,{Co?cppca??H2O?4·2H2O}n?2?,{Cd2?cppca?2?H2O?5}n?3?,{[Cd3?cppca?2?H2P2O7??H2O?6]·2-H2O}n?4?,{Cu?Hcppca?2}n?5?,{[Mn7?cppca?6?Hcppca?2?H2O?10]·2H2O}n?6?have been design and made at room temperature under solvothermal conditions.Compounds 1 and 2 are isomorphic frameworks with 0D mononuclear structure,and the 0D structures were further linked to form a 3D supramolecular framework through hydrogen-bond interaction.3 and 4are 1D chain with different structure due to pyrophosphoric acid methanol solution was added in synthetic process of 4.Complex 5 is 2D layer,in which 1D left-and right-handed helical chains alternately arrayed,and 6 is a complicated 3D network with an unprecedented?3,4,5?-connected topology net.Meanwhile,Variable-temperature magnetic susceptibility measurements indicate weak antiferromagnetic interactions between metal centers in 1,2,5and 6.The fluorescent properties of compounds 3 and 4 were investigated and we can see strong blue fluorescence of 3 and 4 directly under ultraviolet light.The fluorescence properties of 3 and 4 were investigated in various solvent emulsions,which indicated thatthey are both highly sensitive fluorescent probes for the acetone molecules.2.Three coordination compounds based on H2 cppca and zinc acetate,{Zn?cppca?2?H2O?2}n?7?,[Zn?cis-cppca??H2O?]n?8?,[Zn?trans-cppca??H2O?]n?9?have been design and made at room temperature under hydrothermal and solvothermal conditions.Compounds 7 and 8 were obtained under water solution at different temperature.7 is a mononuclear structure,and the units were further linked to form a 3D supramolecular framework through hydrogen-bond interaction.8 is an abnormal 2D puckered layer,and the2 D layers are interdigitated with each other into a 3D supramolecular network through ?···?interactions.The 3D framework 9 with 1D channels was obtained from the CH3CN/H2 O mixed solvent systems.Although 9 have same molecular formulas and coordination modes with compound 8,the different skeletal structure was discovered in 9 due to the C-C single bonds between phenyl and pyridyl rings of H2 cppca can rotate freely result in cis-and trans-conformations in the compound 8 and 9 respectively.The solid fluorescent properties of compounds 8 and 9 were investigated and the fluorescence properties of 8 and 9 were investigated in various solvent emulsions,which indicated that 9 is also highly sensitive fluorescent probes for the acetone molecules.Further,the dye adsorption properties of compound 9 were investigated,showing certain degree of absorption for MB and RhB dyes.3.Four homogeneous lanthanide complexes Ln2?cppca?2?OX??H2O?4?Ln = Eu?10?,Tb?11?,Pr?12?and Gd?13??have been synthesized by using H2 cppca as primary ligand,oxalic acid?H2OX?as subsidiary ligand and lanthanide nitrates by hydrothermal conditions.The single-crystal X-ray diffraction studies revealed that complexes 10-13 are isomorphic frameworks with a 3D network,in which the H2 cppca coordinate with metal ions to form tetragonal prism and the prisms are further linked by oxalic acid to form a 3D backbone.The complexes 10 and 11 emit red and green light respectively under ultraviolet light,indicating that the ligand can transfer the energy to Eu?III?ions and Tb?III?ions effectively and sensitized Eu?III?and Tb?III?resulted in fluorescene. |
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