Work

A Dicationic Diradicaloid through Intramolecular One‐Electron Transfer from a B‐B σ‐Bond to an Aromatic π‐System

Year: 2026

Type: article

Abstract: ABSTRACT Herein we report on a novel type of main group diradicaloid with the triplet state arising from unprecedented reversible intramolecular one‐electron transfer from a B‐B σ‐bond (HOMO) into a boron‐bound organic π‐acceptor orbital (LUMO of pyrazine). The deep‐red bis(diboranyl)pyrazine dication, with a bridging pyrazine between two diboranyl units and sp 3 ‐hybridised boron atoms, represents also the first example for a fully‐reversible thermal redox equilibrium between a diborane as electron donor and an organic π‐acceptor. The compound is stable in solution and in the solid state under ambient conditions. Two modified systems were synthesised, demonstrating that a decrease of the B‐B σ‐bond orbital energy as well as an increase of the π*‐acceptor orbital energy leads to an extinction of the diradicaloid character.

Source: Angewandte Chemie

DOI: 10.1002/ange.2253264

Authors: Lea Haas, Maximilian Schulz, Olaf Hübner, Elisabeth Kaifer, Hans‐Jörg Himmel

Institution: Heidelberg University

Language: English

Topic: Organoboron and organosilicon chemistry

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $5,790

Funder: Deutsche Forschungsgemeinschaft