Three new POM-based coordination polymers with 1,3,5-tris(1-imidazolyl)benzene ligand: syntheses, structures and proton conductivity

Three new POM-based coordination polymers, [Cu(timb)(2)(W6O19)](n) (1), {[Zn-3(Htimb)(2)(H(2)timb)(2)(H2O)(2)(ZnW12O40)(2)]center dot 2H(2)O}(n) (2), and {[Ni(Htimb)(H2O)(3)(H2W12O40)(0.5)]center dot 3H(2)O}(n) (3) (timb = 1,3,5-tris(1-imidazolyl)benzene), have been prepared under hydrothermal conditions. Compound 1 contains one 3D framework constructed by Cu-II atoms and timb ligands with a rare 3,6-connected pyr topology, while the polyoxoanions are situated in the cavities. For compound 2, the 3D framework is composed of a 2,4-connected network (A) and hcb network (B) in the BBABB mode. The 1D chains of compound 3 are arranged into a 3D framework by a variety of hydrogen bonding interactions between the [H2W12O40](6-) polyoxoanions, coordinated water molecules and free water molecules. Magnetic data of compounds 1 and 3 show the presence of antiferromagnetic behavior. In addition, the highest proton conductivities of compounds 2 and 3 reach 2.32 x 10(-5) S cm(-1) and 3.38 x 10(-5) S cm(-1) at 358 K and 98% RH, respectively.

Automated summary

Three new POM-based coordination polymers have been synthesized and characterized in this study. Compound 1 features a unique 3D framework structure, while compounds 2 and 3 have framework structures composed of different connectivity modes. In addition, high proton conductivity and antiferromagnetic behavior were observed in compounds 2 and 3.