engleski

Flexibility of crystalline matter: Crystals of coordination polymers with a variety of mechanical responses

In addition, to be stiff and brittle, crystals have for a long been regarded as stationary objects. These days we are witnessing a paradigm shift in the percieving crystalline matter as static - crystals have been recently found to move, jump, flex, or explode, but lately also to respond to the applied external mechanical force. These latest observations were noticed only for a bunch of organic crystals and a sole single 0-D metal complex. Very recently, we reported on a class of crystalline coordination polymers of cadmium(II) capable of displaying exceptional mechanical elasticity in response to the application of external pressure. The structural 1-D spine was equipped with small and rigid heterocyclic ligands having halogen functionality adjacent to the heterocyclic nitrogen atom, thus producing a supramolecular moiety capable of forming both hydrogen and halogen bonds. We have shown that slight differences in the importance of intermolecular interactions in crystal packing together with substantial structural interlocking that is orthogonal to the direction of crystal elongation are critical for inducing the highly unusual mechanical responses of crystalline metal- based polymeric materials. To fully understand the structural features that need to be present for mechanical flexibility to be imparted to crystalline materials, we are reporting on a similar family of crystalline coordination polymers with a variety of responses to exerted external mechanical force. For tailoring the structural spine, here we are employing two different metal(II) cations cations in a combination with the halide anions, while for tuning the nature and extent of mechanical response we are using several supramolecular moieties.

coordination compounds, cadmium(II), flexible crystals

nije evidentirano