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

Abstract

The synthesis, structures and properties of five Cd(II) coordination networks: [Cd(bpdc)(L1)]n [L1 = N,N′-di(4-pyridyl)adipoamide; H2bpdc = 4,4′-biphenyldicarboxylic acid], 1; {[Cd2(1,4-ndc)2(L1)2(H2O)]·H2O·2DMF}n (1,4-H2ndc = naphthalene-1,4-dicarboxylic acid), 2; {[Cd(OBA)(L1)]·2H2O}n [H2OBA = 4,4′-oxybis(benzoic acid)], 3; {[Cd(SDA)(L1)]·1.5H2O}n (H2SDA = 4,4′-sulfonyldibenzoic acid), 4; and {[Cd(1,4-ndc)(L2)(H2O)]·2H2O}n [L2 = 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 N2 in the gas sorption for the desolvated product of 1.