Interpenetrated and polycatenated nets of Cd(II) coordination networks from mixed N,N′-dipyridyladipoamide and dicarboxylate ligands

The synthesis, structures and properties of five Cd(II) coordination networks: [Cd(bpdc)(L-1)](n) [L-1 = N,N'-di(4-pyridyl)adipoamide; H(2)bpdc = 4,4'-biphenyldicarboxylic acid], 1; {[Cd-2(1,4-ndc)(2)(L-1)(2)(H2O)]center dot H2O center dot 2DMF}(n) (1,4-H(2)ndc = naphthalene-1,4-dicarboxylic acid), 2; {[Cd(OBA)(L-1)]center dot 2H(2)O}(n) [H(2)OBA = 4,4'-oxybis(benzoic acid)], 3; {[Cd(SDA)(L-1)]center dot 1.5H(2)O}(n) (H(2)SDA = 4,4'-sulfonyldibenzoic acid), 4; and {[Cd(1,4-ndc)(L-2)(H2O)]center dot 2H(2)O}(n) [L-2 = N,N'-di(3-pyridyl)adipoamide], 5, are reported. Complexes 1 and 2 show the pcu and fsd topologies with 2- and 3-fold interpenetrating modes, respectively, and complex 4 exhibits a 2-fold 2D -> 2D parallel interpenetration network containing a rotaxane-like motif. Complex 3 is a 1D -> 2D polycatenane derived from the helical channels, and the 2D layers are further mutually interdigitated, whereas complex 5 is a 2D -> 3D polycatenane based on the undulating sql sheets. These five complexes show different thermal and luminescent properties and the CO2 capture is preferable to N-2 in the gas sorption for the desolvated product of 1.