engleski

Cadmium(II) coordination polymers with pyrazinamide ligand displaying different degree of flexibility

Mechanical responsiveness, a property that was considered highly uncharacteristic for crystalline material, recently showed to be the feature of a growing number of organic, and only a few metal- organic compounds. There are reports of crystals bending, jumping and even exploding upon applying different kinds of stimuli. Recently, for the first time, we reported on a class of coordination polymers of cadmium(II) with halopyrazine ligands that give elastic response upon application of mechanical stress that can be fine-tuned by implying slight structural changes. Such molecular crystals, that give flexible response upon applying mechanical force can find potential use in different fields of practical life such as flexible electronics, smart textile materials, and clever molecular machines. However, the mechanism that leads to this kind of behavior of crystalline materials is not yet understood. In order to investigate crystal bending of the metal-organic compounds and the link between the supramolecular structure and extent of the mechanical response, we synthesized another class of cadmium(II) coordination polymers with pyrazine ligand bearing amide functionality capable of forming hydrogen bonds of desired supramolecular connectivity. Crystals of appropriate morphology showed substantial elastic response upon application of mechanical force. The extent of the observed elastic bending was quantified and related to the structural characteristics of the crystals. Slight changes in unit cell parameters of bent crystals were mapped-out as well.

cadmium(II) coordination polymers, pyrazinamide, flexibile crystals

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