Heteroleptic Copper Switches

摘要

Heteroleptic copper compounds have been designed and synthesized on solid supports. Chemical redox agents were used to change the oxidation state of the SiO_2-immobilized heteroleptic copper compounds from Cu(l) to Cu(ll) and then back to Cu(l). Optical spectroscopy of a dimethyl sulfoxide suspension demonstrated the reversibility of the Cu(l)/Cu(ll) SiO_2-immobilized compounds by monitoring the metal-to-ligand charge transfer peak at about 450 nm. Electron paramagnetic resonance spectroscopy was used to monitor the isomerization of Cu(l) tetrahedral to Cu(ll) square planar. This conformational change corresponds to a 90° rotation of one ligand with respect to the other. Conductive atomic force microscopy and macroscopic gold electrodes were used to study the electrical properties of a p~+ Si-immobilized heteroleptic copper compound where switching between the Cu(l)/Cu(ll) states occurred at -0.8 and +2.3 V.