3D Coordination Polymer of Cd(II) with an Imidazolium-Based Linker Showing Parallel Polycatenation Forming Channels with Aligned Imidazolium Groups

A novel entangled architecture formed on solvothermal reaction of a imidazolium based bent ligand with Cd­(NO₃)₂, showing 1D channels decorated with imidazolium groups, is reported. The polymer, {[Cd₂(L)₃(DMF)­(NO₃)]­(DMF)₃(H₂O)₈}_n (1) (where H₂L = 1,3-bis­(4-carboxyphenyl)­imidazolium, DMF = dimethylformamide), shows an interesting 6,3-connected polycatenated structure with channels along the crystallographic b-axis occupied with large number of DMF and water molecules. On removal of these solvent molecules the compound maintains its overall structure. Proton conductivity investigation affords a proton conductivity of 1.3 × 10^–5 Scm^–1 at 25 °C and 98% RH when water molecules are introduced into the empty channels.