Preparation And Application Of Transition Metal Complexes Based On 2-iodo-5-sulfobenzoic Acid

In recent years,because of the diversity of metal coordination polymer structures and attractive topology,as well as the potential application value in catalysis,fluorescence and other related aspects,the design and synthesis of new metal coordination polymer has attracted extensive attention of scientists.Sulfonic metal coordination polymers based on sulfonic acid ligands and nitrogen-containing flexible ligands and transition metal ions have been widely reported.In this thesis,six coordination polymers were successfully constructed solvo(hydro)thermally through the assembly between 2-iodo-5-sulfobenzoic acid(H2isba)and transition metal ions(Cd2+/Co2+/Cu2+/Zn2+)in the presence of the flexible bis(imidazole/triazole)-category ligand,namely {[Cd(isba)(bbbm)1.5(H2O)2]·4H2O·2DMF}n(1),{[Co(isba)(bbbm)1.5(H2O)2]·4H2O·2DMF}n(2),{[Cd(Hisba)2(bbtz)2]·bbtz}n(3),{[Cu(isba)(bbtz)3]-2H2O}n(4),{[Zn(isba)(bix)(H2O)]·H2O·DMF}n(5)and{[Zn(isba)(bix)1.5]·3H2O}n(6).The purity of six coordination polymers was confirmed by elemental analysis and powder X-ray diffraction analysis(PXRD).The fluorescence sensing properties of complexes 1 and 2 toward some metal ions,Cr(VI)anions(Cr2O72-/CrO42-)and some NACs were studied.The photocatalytic degradation properties of complexes 1,3,4,5 and 6 for dyes[methyl orange(MO),methylene blue(MB)and Rhodamine B(RB)]were investigated in detail.The main work is introduced briefly as follows:1.Two new coordination polymers,{[Cd(isba)(bbbm)1.5(H2O)2]·4H2O·2DMF}n(1)and{[Co(isba)(bbbm)1.5(H2O)2]-4H2O·2DMF}n(2),were obtained through the assembly between the mixed H2isba and bbbm ligands with the related Cd2+/Co2+ions,respectively[bbbm=1,1'-(1,4-butanediyl)bis-1H-benzimidazole].1 and 2 have different metal centers with similar structures.In 1 and 2,there are one and a half of crystallographic independent bbbm molecules in the asymmetric unit.Two kinds of crystallographic independent bbbm ligands link the adjacent Cd(II)ions alternatingly in TTT {Trans-,Trans-,Trans-)mode,leading to the formation of 1D chains.The adjacent chains are further joined by the other centrosymmetric bbbm ligand with GTG(Gauch-,Trans-,Gauch-)mode,resulting in a 2D framework with 66-membered macrometalcyclic ring.The isba-ligand shows monodentate coordination mode and occupies within the cyclic ring.From topological points of view,if the bbbm ligands were treated as linkers and the central metal ions were treated as nodes,the 2D framework of 1 and 2 can be simplified as a 2D(6,3)topological network.The fluorescence quenching titration experiments show that both complexes could be used as fluorescent probes to sensing of Fe3+ ions,chromate anions and NACs in water.1 is a highly efficient and universal photocatalyst for the degradation of the organic dyes like MO/MB/RB under UV light irradiation.2.Two novel coordination polymers,namely,{[Cd(Hisba)2(bbtz)2]·bbtz}n(3)and{[Cu(isba)(bbtz)3]·2H2O}n(4),were prepared through the reaction between bbtz,H2isba and Zn2+[bbtz=1,4-bis(triazol-1-ylmethyl)benzene].In 3,the central Cd(?)ions are bridged by the ligand bbtz,leading to the formation of 1D chain,in which Hisba-is not completely deprotonated.With the aid of the hydrogen bond(C13-H13...I1),an extended 2D planar structure was formed.In 4,the isba2-ligands link the adjacent Cu(?)ions into an elliptical 16-membered ring,which is further linked by bbtz in GG mode,resulting in a 1D tubular chain.The adjacent tubular chains are further connected by the other bbtz ligands in TT mode,leading to a 2D layered structure.The photocatalytic degradation properties as well as mechanisms of 3 and 4 for MO/MB/RB under UV light irradiation were investigated.The PXRD patterns showed that 3 and 4 are structurally stable during the catalytic process.3.Two temperature-dependent coordination polymers with different structure,namely,{[Zn(isba)(bix)(H2O)]·H2O·DMF}n(5)and {[Zn(isba)(bix)1.5]·3H2O}n(6),are self-assembled between 2-iodo-5-sulfobenzoic acid(H2isba)and Zn2+ion in the presence of the auxiliary ligand 1,4-bis(imidazolyl-1-methyl)benzene(bix).In 5,the neighboring Zn(?)ions are linked by the bix ligands,forming 1D chains.The chains are further linked together by the hydrogen bond(O1W-H1WB...O3),resulting in a 2D layered structure.With the aid of the hydrogen bonds:O2W-H2WB...O2,O2W-H2WA...O1 and O1 W-H1WA...O1,2D layered structure further expands to 3D supramolecular network architecture.The photocatalytic activity of 5 and 6 to dyes under UV-light irradiation was also studied.