Details

Autor(en) / Beteiligte

• Streifel, Benjamin C
• Zafra, José L
• Espejo, Guzmán L
• Gomez-Garcia, Carlos J
• Casado, Juan
• Tovar, John D

Titel

An Unusually Small Singlet-Triplet Gap in a Quinoidal 1,6-Methano[10]annulene Resulting from Baird's 4n [pi]-Electron Triplet Stabilization

Ist Teil von

• Angewandte Chemie International Edition, 2015-05, Vol.54 (20), p.5888

Auflage

International ed. in English

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Within the continuum of π-extended quinoidal electronic structures exist molecules that by design can support open-shell diradical structures. The prevailing molecular design criteria for such structures involve proaromatic nature that evolves aromaticity in open-shell diradical resonance structures. A new diradical species built upon a quinoidal methano[10]annulene unit is synthesized and spectroscopically evaluated. The requisite intersystem crossing in the open-shell structure is accompanied by structural reorganization from a contorted Möbius aromatic-like shape in S0 to a more planar shape in the Huckel aromatic-like T1. This stability was attributed to Baird's Rule which dictates the aromaticity of 4n π-electron triplet excited states.