Stepwise formation of a chemodynamic therapy agent of {Cu8} macrocyclic complex recognized by iodide ions

Abstract

An atomically precise Cu(I) macrocyclic complex Cu₈I was developed for chemodynamic therapy (CDT) research. The {Cu₈} macrocyclic skeleton gradually forms with the selective recognition of iodide ions, and the monitoring of intermediate fragments during Cu₈I formation using time-dependent electrospray ionization mass spectrometry indicates the following possible formation process: [Cu₁] → [Cu₂] → [Cu₃] → [Cu₄] → [Cu₅I] → [Cu₆I] → [Cu₇I] → [Cu₈I] when recognized by iodide ions. Furthermore, the Cu(I)-mediated Fenton-like reaction in Cu₈I catalyzes the production of toxic ˙OH from H₂O₂, which results in efficient tumor suppression.