Distortions of a flexible metal-organic framework from substituted pendant ligands

Solvothermal crystallization of cobalt(II) 1,4-benzenedicarboxylates in the presence of substituted pyridine-N-oxides as co-ligands yields four new materials whose structures have been solved and refined from single-crystal X-ray diffraction data. The phases all have structures related to the metal-organic framework MIL-53 with the pyridine-N-oxide acting as a pendant ligand, projecting into the pores of the structure giving new distortions of the well known metal-organic framework (MOF) structure.