Coordination-polymeric nanofibers and their field-emission properties^a

The large-scale fabrication of nanofibers of coordination polymers (CPs) is reported for the first time from CP gel precursors by the electrospinning method. In the absence of organic polymeric additives, viscous solutions suitable for drawing fibers have been made by diluting the gel precursors, which are obtained by mixing Ni(OAc)₂and 4-trifluoromethylbenzoic acid with 4,4′-bis(pyridyl)ethylene (bpe) or 4,4′-bipyridine (bpy) linear spacer ligands in organic solvents. One-dimensional polymeric structures have been proposed for these gels and nanofibers based on the crystal structures of the compounds isolated. These fibers show some interesting field-emission properties. The results described here may well be extended to other one-dimensional polymers, thus opening the door for processing of the coordination polymers.