Smart composite films of nanometric thicknessbased on copper–iodine coordination polymersToward sensors

摘要

One-pot reactions between CuI and methyl or methyl 2-amino-isonicotinate give rise to the formation oftwo coordination polymers (CPs) based on double zig–zag Cu2I2 chains. The presence of a NH2 group inthe isonicotinate ligand produces different supramolecular interactions affecting the Cu–Cu distancesand symmetry of the Cu2I2 chains. These structural variations significantly modulate their physicalproperties. Thus, both CPs are semiconductors and also show reversible thermo/mechanoluminescence.X-ray diffraction studies carried out under different temperature and pressure conditions in combinationwith theoretical calculations have been used to rationalize the multi-stimuli-responsive properties.Importantly, a bottom-up procedure based on fast precipitation leads to nanofibers of both CPs. Thedimensions of these nanofibres enable the preparation of thermo/mechanochromic film compositeswith polyvinylidene difluoride. These films are tens of nanometers in thickness while being centimeters inlength, representing smaller thicknesses so far reported for thin-film composites. This nanomaterialintegration of CPs could represent a source of alternative nanomaterials for opto-electronic devicefabrication.