Dielectric transitions and relaxations in Ca(ii)Co(iii)-based cyanometallate frameworks with a rare (6,6)-connected nia topology.

A series of cyanometallate frameworks A[CaCo(CN)] (A = protonated guanidine, urea or thiourea guest) exhibit a rare (6,6)-connected nia topology with the Schläfli symbol of (4·6)(4·6) and thermally driven dielectric transitions and relaxations without evident structural phase transitions.