Reversible switching of the electronic ground state in a pentacoordinated Cu(ii) complex

Abstract

An easy reversible switching of the electronic ground state in a pentacoordinated copper(II) complex is reported for the first time. The simple protonation of a carboxylic group in a Cu(II) complex with a {d_x²−y²}¹ electronic configuration leads to a flip of the ground electronic configuration from {d_x²−y²}¹ to {d_z²}¹ in the metal ion.