Cadmium carboxycinnamate coordination polymers with dimensionality differences depending on dipyridyl ligand

• Three new cadmium carboxycinnamate coordination polymers.
• Nature of dipyridyl coligand dictates dimensionality and topology.
• (4, 4) Grid with kinked dipyridyl ligands penetrating through the grid apertures.
• (6, 3) Herringbone and 3-D 6-connected topologies for longer dipyridines.
• Moderate to intense blue-violet emission upon UV irradiation.

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.

Three strongly luminescent cadmium carboxycinnamate coordination polymers with hydrogen-bonding capable dipyridyl ligands were prepared. {[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. Interdigitated (6, 3) herringbone layers and a dimer-based pcu 3-D network are seen for longer dipyridyl ligands.Figure optionsDownload as PowerPoint slide