Syntheses,Structures And Fluorescent Properties Of Metal-organic Coordination Polymers Containing Zn(?) And Pb(?)

Coordination polymers are made by metal ions or metal clusters with organic ligands through self-assembly.Because of the various structures and unique properties,Coordination polymers have widely been applied in the area of chemistry,material and bioscience.The main content of this paper is to study the syntheses,structures and fluorescence properties of six new Zn(II)/Pb(II)metal-organic coordination polymers,which are divided into four parts: In the part one,we discussed the in situ reaction of the formation of metal complexes.Firstly,the in situ reaction of transition metal zinc(II)was designed and explored.Interestingly,two new zinc(II)coordination polymers namely [Zn3(IPT)2(DPA)2](1),[Zn3(IPT)2(PYDC)2)·2H2O](2),were successfully isolated via the in situ reaction of zinc nitrate,sodium azide and the organic ligands,such as1-(4-cyanophenyl)imidazole(CPI),5-[4-(imidazol-1-yl)phenyl]tetrazole(HIPT),[1,1'-biphenyl]-2,2'-dicarboxylic acid(H2DPA),and pyridine-2,4-dicarboxylic acid(H2PYDC)under the hydrothermal conditions;Secondly,the in situ reaction of the main metal lead(II)is further studied,that is,through the reaction of pyrimidine-2-carbonitrile(2-Pm CN)as organic ligands,lead acetate and sodium azide under the solvothermal condition.Most interestingly,two new lead(II)coordination complpolymers,[Pb(L1)2](3)[Pb4(O)2(NO3)2(ox)](4)were successfully achived by adjusting the amount of sodium azide during the reaction progress;Thirdly,the effect of organic ligands on the in situ reaction was discussed.By hydrothermal synthesis method,[1,1'-biphenyl]-2,2'-dicarboxylic acid(H2DPA)2,2'-azanediyldibenzoic acid(H2L2)as ligand,with lead acetate and sodium azide,two complexes were synthesized: [Pb3O(DPA)2](5),[Pb7O2(OH)2(L2)4](6).In the part two,the solid fluorescence properties and thermal stabilities of six complexes were studied.In the part three,the fluorescence recognition properties of the complexes(5)and(6)for organic molecules,inorganic cations and inorganic anions were studied and studied.In the part four,the coordination model of complexes(1)and(2)was analyzed by using time-dependent density functional theory.It was found that two kinds of in situ reactions were able to obtain different in situ reaction coordination when changing ligand coordination mode and the possible reaction mechanism was put forward.At the same time,the luminescence mechanisms of the two complexes were investigated by the theoretical calculation results.