The diverse structures of Cd(II) coordination polymers with 1,3,5-benzenetribenzoate tuned by organic bases

The reaction of CdCl2 center dot 1.5H(2)O with 1,3,5-benzenetribenzoic acid (H3BTB) in DMF gave {[Cd-3(BTB)(2)(DMF)(4)]center dot 3DMF}(n) (1), while the reactions of Cd(Ac)(2)center dot 2H(2)O with H3BTB in DMF/H2O (1 : 10) in the presence of py, bpy, and bib generated {(Hpy)[Cd(BTB)(py)]center dot 0.5DMF center dot 3H(2)O}(n) (2), {Cd [Cd-2(BTB)(2)(bpy)]center dot 2bpy center dot DMF center dot 19H(2)O}(n) (3), and {[Cd-3(BTB)(2)(bib)(3)(H2O)(2)]center dot 4H(2)O}(n) (4), respectively (DMF N,N'-dimethylformamide, py = pyridine, bpy 4,4'-bipyridine, bib = 1,4-bis(imidazol-1-yl) butane). X-Ray single-crystal analyses reveal that 1 contains a two-dimensional bilayer structure based on a carboxylate and DMF bridged Cd-3 cluster. In 2, two honeycomb-like [Cd(BTB)](n)(n-) sheets are interpenetrated with each other to form a 2D network. In 3, the 2D [Cd(BTB)](n)(n-) honeycomb-like sheets are pillared by bpy to form a 3D framework, and the 3D frameworks are three-fold interpenetrated to generate the framework of 3 with 1D open channels, which are occupied by disordered Cd ions, bpy, DMF and water molecules. Compound 4 consists of a 3D self-penetrated framework constructed by mu(2)-bib bridging five-fold interpenetrated 2D bilayers. The results of gas sorption measurements indicate that the desolvated 3 can selectively adsorb CO2 and H-2 over N-2, with a rare large hydrogen sorption hysteresis. The luminescent properties of 1-4 were also investigated.