A Stable Crystalline Triarylphosphine Oxide Radical Anion

Tobias A Schaub; Eva M Zolnhofer; Dominik P Halter; Tatyana E Shubina; Frank Hampel; Karsten Meyer; Milan Kivala

doi:10.1002/anie.201605963

A Stable Crystalline Triarylphosphine Oxide Radical Anion

Angew Chem Int Ed Engl. 2016 Oct 17;55(43):13597-13601. doi: 10.1002/anie.201605963. Epub 2016 Sep 27.

Authors

Tobias A Schaub¹, Eva M Zolnhofer², Dominik P Halter², Tatyana E Shubina³, Frank Hampel¹, Karsten Meyer², Milan Kivala⁴

Affiliations

¹ Chair of Organic Chemistry I, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Henkestrasse 42, 91054, Erlangen, Germany.
² Chair of General and Inorganic Chemistry, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany.
³ Computer Chemistry Center (CCC), University of Erlangen-Nürnberg, Nägelsbachstrasse 25, 91052, Erlangen, Germany.
⁴ Chair of Organic Chemistry I, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Henkestrasse 42, 91054, Erlangen, Germany. milan.kivala@fau.de.

PMID: 27671541
DOI: 10.1002/anie.201605963

Abstract

Triarylphosphine oxides (Ar₃ P=O) are being intensely studied as electron-accepting (n-type) materials. Despite the widespread application of these compounds as electron conductors, experimental data regarding the structural and electronic properties of their negatively charged states remain scarce owing to their propensity for follow-up chemistry. Herein, a carefully designed triarylphosphine oxide scaffold is disclosed that comprises sterically demanding spirofluorenyl moieties to shield the central phosphoryl (P=O) moiety. This compound undergoes chemical one-electron reduction to afford an exceptionally stable radical anion, which was isolated and characterized by X-ray crystallography for the very first time. The experimental data, corroborated by computational studies, shall allow for the construction of phosphine oxide materials with enhanced stability.

Keywords: cyclization; phosphorus heterocycles; polycyclic systems; radical anions.

Publication types

Research Support, Non-U.S. Gov't