A tetracarboxylate-bridged dicopper(II) paddle-wheel-based 2-D porous coordination polymer with gas sorption properties

The synthesis, crystal structure, and sorption properties of [Cu-2(bdc)(2)(dmf)]H2O center dot(dmf)(C2H5OH)(0.5) (2.g, g = dmf center dot H2O center dot(C2H5OH)(0.5), bdc = 1,3-benzenedicarboxylate, dmf = N,N'-dimethylformamide) are reported. 2.g features upended bowl cavities with an outer diameter of 9.4 angstrom, which are enclosed by four tetracarboxylate-bridged Cu-2 paddle-wheels and extended by dicarboxylate linkers into a two-dimensional (2-D) coordination polymer. The metal-organic layers are further stacked in a slipped manner through van der Waals interactions to generate a three-dimensional (3-D) supramolecular structure having 2-D channels that accommodate the solvent molecules. After removal of the solvent molecules, solid 2 exhibits permanent porosity verified by an N-2 sorption isotherm with a Langmuir surface area of 629 m(2).g(-1) and Brunauer-Emmett-Teller (BET) surface area of 374 m(2).g(-1). Moreover, solid 2 also displays interesting methanol and benzene vapor sorption behaviors with large hysteresis and incomplete desorption, which is attributed to the chemisorption.