One-dimensional nanoporous M2L2 rhombohedral molecular square with strong blue fluorescent emission

The hydrothermal reactions of Zn(ClO4)2 · 6H2O and Cd(ClO4)2 · 6H2O with the ligand N,N′-bis(pyridylcarbonyl)-4,4′-diaminodiphenyl ether (L) afford two one-dimensional (1D) coordination polymers, ([CdL(ClO4)2 · (H2O)2] · 2H2O) (1) and [ZnL(ClO4)2 · (H2O)2] · 2H2O, (2) having a nanoporous M2L2 rhombohedral molecular square with an approximately accessible cavity of 12.9 × 12.9 (1) and 12.7 × 12.7 (2) Å without any interpenetrations. Both 1 and 2 are isostructural and display very strong blue fluorescent emission in the solid state at room temperature.