Work

The crystalline radical anion salt of a free N-heterocyclic carbene

Year: 2026

Type: article

Abstract: Free N-heterocyclic Carbene (NHC) radical ions have remained short-lived, mostly elusive, intermediates so far. We probed the square schemes for proton-coupled electron transfers of representative redox-active free NHC. We found that NHC radical anions NHC •– and/or the conjugated acid NHC•H • could be persistent. In the case of a benzoquinone-based NHC, both radical forms were isolated as stable crystalline compounds, characterized, including with single-crystal X-ray diffraction studies, and were engaged in the straighKorward divergent syntheses of NHC-based radicals.

Source: Chemical Science

DOI: 10.1039/d6sc05617b

Authors: Preslav Smits, Jacques Pecaut, Christian Philouze, Jérome Fortage, Eder Tomás-Mendivil, David Martin