Synthesis and characterization of a novel modular cadmium-organic framework with biphenyl-4,4′-dicarboxylate

We report the synthesis and structural characterization of a thermally stable and highly crystalline novel metal-organic framework with cadmium(II) ions. The crystal structure is formed by a threefold interpenetration of identical three-dimensional modular frameworks, assembled by the repetition of a binuclear secondary building unit. This unit contains 1,2-bis(4-pyridyl)ethane and introduces biphenyl-4,4′-dicarboxylate as an effective rigid large spacer between metal centres. Water molecules are hydrogen bonded to carboxylate groups and act as bridges between each independent framework. To the best of our knowledge, CUmof-1 is the first structure in which the paddlewheel motif is associated with a distribution of cavities in a concertina manner.