The Synthesis,Structure And Properties Of The Co,Ni Coordination Polymers Based On Bipyridyl Ligands

Coordination polymers?CPs?based on bipyridyl ligands have important potential applications in the fields of catalysis,electrochemistry,gas adsorption,biomedicine,etc,research on such a polymer has gradually become one of the frontier research hotspots in related fields.In this paper,the larger electronic derivatized system1,4-di?4-pyridyl?benzene?Bpb?and 4,4'-di?4-pyridyl?biphenyl?Bpbp?were selected as the main ligand,SCN^-and halogen as an auxiliary ligand,after adjusting various reaction conditions,the transition metal cobalt and nickel ions were reacted under suitable conditions,and 11 target CPs were successfully prepared.The paper systematicallyexploredthecrystalstructure,luminescenceproperties,photoelectrochemical properties,thermal stability of various target CPs,and the structure-activity relationship between the structure and properties.The main research contents are as follows:1.SixtargetCPswereobtainedbysolvothermalreactionwith1,4-di?4-pyridyl?benzene?Bpb?as the main ligand and thiocyanate as the auxiliary ligand:[Co?SCN?₂?Bpb?₂]?1?,[Ni?SCN?₂?Bpb?₂]?2?,[Ni?SCN?₂?Bpb?]?3?,[Ni₂?SCN?₄?Bpb?₃]·2DMF?4?,[Ni₂?SCN?₄?Bpb?₃]·2CH₃CN?5?,[Ni₂?SCN?₄?Bpb?₃]·2CH₃CH₂OH?6?.Single crystal X-ray diffraction analysis reveals that CPs 1,2 exhibiting a two dimensional grid structure,and CP 3 exhibits a two dimensional layer structure.Solid UV diffuse reflectance indicates that the difference between band gap of CPs 1 and 2 are small,and the luminescence experiments show that their fluorescence property are similar.Compared with 2,the peak shape of the fluorescence emission of CP 3 is changed,and the band gap is narrower.The CPs 4,5,6exhibit two dimensional stair structure.For isomorphic substances 4,5 and 6 with only different solvent molecules,experiments have shown that the small difference in solid UV and fluorescence properties.Photoelectrochemical experiments show that CPs 1,4,5 have good photosensitivity and reproducible photoreactive current.2.Five target CPs are successfully obtained with 4,4'-di?4-pyridyl?biphenyl?Bpbp?as the main ligand,thiocyanate and halogen as auxiliary ligands,and reacted with cobalt andnickelions:[Co₂Cl₂?SCN?₂?Bpbp?₃]?7?,[Co₂Br₂?SCN?₂?Bpbp?₃]?8?,[Ni?SCN?₂?DMF?₂?Bpbp?]?9?,[Ni?SCN?₂?Bpbp?]?a Phase??10?,[Ni?SCN?₂?Bpbp?]?b Phase??11?.The crystal structure,luminescence properties of all target products were systematically characterized.CP 9 exhibits one dimensional linear structure,and other CPs exhibit two dimensional layer length structure.Experiments show that the peaks of fluorescence emission caused by the difference of halogen atoms in 7,8 are different,the band gap of 8 is narrower,and the thermal stability of 7 is higher.The band gap of 9is larger.The peaks of the fluorescence emission of 10 and 11 are different,and the band gap differs by 0.07 eV.Photoelectrochemical performance experiments show that CPs 7and 10 have good photosensitivity and stability,and are expected to be used to modify the electrode product oxygen.