Cadmium carboxycinnamate coordination polymers with dimensionality differences depending on dipyridyl ligand

Hydrothermal reaction of cadmium nitrate, carboxycinnamic acid (H2cca), and a tethering hydrogen-bonding capable dipyridyl ligand afforded three new crystalline coordination polymers, which were characterized by single-crystal X-ray diffraction. {[Cd(cca)(dpa)2]·2H2O}n (1, dpa = 4,4′-dipyridylamine) shows a (4, 4) coordination polymer layer, but with pendant dpa ligands curling in through the grid apertures. {[Cd(cca)(4-bpmp)(H2O)]·2H2O}n (2, 4-bpmp = bis(4-pyridylmethyl)piperazine) also has a 2-D coordination polymer layer structure, but with closely interdigitated (6, 3) herringbone motifs. [Cd(cca)(4-bpfp)]n (3, 4-bpfp = bis(4-pyridylformyl)piperazine) manifests a {Cd2(OCO)2} dimer-based 6-connected pcu 3-D network. All three materials undergo modest to strong blue-violet fluorescence under ultraviolet radiation. Thermal decomposition behavior is also probed.