Three-dimensional porous Cd(II) coordination polymer with large one-dimensional hexagonal channels: high pressure CH4 and H2 adsorption studies.

A new porous and hydrothermally stable three-dimensional (3D) coordination polymer {[Cd(bpydb)] · 6H2O}n (1) has been synthesized under solvothermal condition from a new rigid ligand 4,4'-(4,4'-bipyridine-2,6-diyl) dibenzoic acid (H2bpydb) and Cd(NO3)2 · 6H2O. Single crystal X-ray analysis shows that 1 has a 5-connected 4(4)6(6) vma net with one-dimensional (1D) hexagonal channels filled with water molecules. Integrity of the framework is maintained upon removal of the water molecules by heating to result in a porous framework. Low pressure N2 and high pressure H2 and CH4 sorption studies along with water adsorption studies were performed on this framework.