Reactivity of copper(i) complexes supported by tripodal nitrogen-containing tetradentate ligands toward gaseous diatomic molecules, NO, CO and O2†

Abstract

Series of Cu(I) complexes supported by nitrogen-based tetradentate ligands were examined for their reactivity toward nitric oxide (NO). The copper complexes generated the corresponding Cu(II)–nitrite complexes in the presence of an excess molar amount of NO. A higher reactivity of the Cu(I) complexes toward NO was observed with a more negative Cu(I/II) redox potential, same as their reactivity toward O₂ and CO, while [Cu^I(tepa)]⁺ with the most positive oxidation potential only reacted with NO among the diatomic gaseous molecules (NO, O₂, and CO) examined in this study. DFT studies explained that the reactivity of the Cu–NO complex was the key to its selectivity rather than its coordination bond stability.