A Stable Crystalline Triarylphosphine Oxide Radical Anion.
Triarylphosphine oxides (Ar3P=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.
Chair of Organic Chemistry I, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Henkestrasse 42, 91054, Erlangen, Germany.
Tobias A
TA
Schaub
Chair of General and Inorganic Chemistry, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany.
Eva M
EM
Zolnhofer
Chair of General and Inorganic Chemistry, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany.
Dominik P
DP
Halter
Computer Chemistry Center (CCC), University of Erlangen-Nürnberg, Nägelsbachstrasse 25, 91052, Erlangen, Germany.
Tatyana E
TE
Shubina
Chair of Organic Chemistry I, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Henkestrasse 42, 91054, Erlangen, Germany.
Frank
F
Hampel
Chair of General and Inorganic Chemistry, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany.
Karsten
K
Meyer
Chair of Organic Chemistry I, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Henkestrasse 42, 91054, Erlangen, Germany. milan.kivala@fau.de.
Milan
M
Kivala
cyclization; phosphorus heterocycles; polycyclic systems; radical anions