The Synthesis,Structure And Properties Of The D¹⁰ Metal Coordination Polymers Based On Bipyridyl Ligands

Bipyridyl ligands have large?-conjugated bond in the molecule,which can form coordination bond,hydrogen bond and?-?stack of aromatic ring with the transition metal ions.Thereby constructing coordination polymers?CPs?with novel structure and special function.In this paper,five kinds of conjugated bipyridyl ligands with different degrees of electron delocalization with SCN^-and d¹⁰metal ions,is assembled into CPs with different structure under suitable conditions.Thesis mainly explores structure,optical performance,photoelectrochemical properties of target products,and the structure-activity relationship.1.Three CPs were obtained by using Bpb?1,4-bis?pyrid-4-yl?benzene?ligand:[Zn?SCN?₂?Bpb?]?CH₃CN?1?,[Zn?SCN?₂?Bpb?]?CH₃CN?2?,[Cd?SCN?₂?Bpb?]?CH₃CN?3?.CP 1 is one-dimensional zigzag chain which linked by chemical bond,and the chains are stacked into a two-dimensional layer by?-?interaction between ligands,the two-dimensional layer form three-dimensional skeleton by hydrogen bond;CP 2 show one-dimensional zigzag chain,which are further linked to two-dimensional layer structures by?-?interaction;CP 3 is three-dimensional framework structure that the Bpb ligands bridge two-dimensional neutral inorganic layer[Cd?SCN?₂]_n.CP 1,2 have different crystal structures witch have same molecular formula.The fluorescence and band gap of the two CPs are 30 nm and 0.15 eV apart,respectively;Its are n-type semiconductors,and having photoelectrochemistry response.The thermal stability of the three CPs are good,indicating that the materials have good practical value.Four CPs were synthesized by using Bpbp?4,4'-bis?Pyrid-4-yl?biphenyl?ligand:[Zn?SCN?₂?Bpbp?]?2CH₃CN?4?,[Cu?SCN??Bpbp?]?5?,[Cu₂?SCN?₂?Bpbp?]?6?,[Hg?SCN?₂?Bpbp?]?7?.The structure of CP 4 and 2 are similar,and all of them show one-dimensional zigzag chain which linked by chemical bond,the chain is stacked into wavy two-dimensional layer by?-?interaction;In CP 5,Cu⁺and SCN^-form one-dimensional zigzag chain,and the wavy two-dimensional skeleton structure formed by Bpbp ligand bridged one-dimensional chain;Firstly,CP 6 and 3 form a neutral two-dimensional inorganic layer,the inorganic layer is further formed three-dimensional skeleton by ligand;CP 7 exhibits one-dimensional zigzag chain,and chain form cross-stacked wavy two-dimensional layer by?-?interaction of ligands.Due to the Bbpb ligand has a large conjugation,the four polymers with the d¹00 metal exhibited better fluorescence properties.The thermal stability of the four CPs are good,and the polymer 4 has an excellent photoelectrochemistry response.2.Three CPs were synthesized by Zn²⁺and other Bipyridyl ligands:[Zn?SCN?₂?Bipy?]·CH₃CN?8?,[Zn?SCN?₂?Bpe?]?9?,[Zn?SCN?₂?Bpey?]?10?.CPs 8and 9 are one-dimensional zigzag chain,and the chains are further stacked into two-dimensional network structure by rich?-?action.The polymer 10 and 1 have similar two-dimensional structure.The fluorescence of all three polymers can be attributed to the ILCT charge transition.Inaddition,ThreeCPs have photoelectrochemistry response that is relatively stable.