Polycarboxylate-Templated Coordination Polymers: Role of Templates for Superprotonic Conductivities of up to 10-1 S cm-1.

Three coordination polymers (CPs) have been synthesized based on a [Co(bpy)(H2 O)4 ]2+ chain (bpy=4,4'-bipyridine) by a template approach. The frameworks are neutralized by different templated polycarboxylate anions (furan di-carboxylate (fdc) in Co-fdc, benzene tri-carboxylate (btc) in Co-tri and benzene tetra-carboxylate (btec) in Co-tetra). These templates with different degrees of protonation and ionic carrier concentration played significant role on crystal packing as well as formation of well-directed H-bonded networks which made these CPs perform well in proton conduction (PC). The PC value reaches to 1.49×10-1  S cm-1 under 80 °C and 98 % relative humidity (R.H.) for Co-tri, which is the highest among CPs/MOFs/COFs and is an example of conductivity in the order of 10-1  S cm-1 . Co-tri and Co-tetra are excellent proton conductors at mild temperature (40 °C) and 98 % R.H. (conductivities up to 2.92×10-2 and 1.38×10-2  S cm-1 , respectively).