Character (mathematics)

Chemical physics

Tetracene

Materials science

Graphene

Singlet fission

Atomic physics

Economics

Molecule

Triplet state

Physics

Nanotechnology

Organic chemistry

Mathematics

Singlet state

Computational chemistry

Zigzag

Geometry

Financial economics

Excited state

Crystallography

Chemistry

Diradical

Derivative (finance)

Angewandte Chemie International Edition

Peri-acenes are good model compounds for zigzag graphene nanoribbons, but their synthesis is extremely challenging owing to their intrinsic open-shell diradical character. Now, the successful synthesis and isolation of a stable peri-tetracene derivative PT-2ClPh is reported; four 2,6-dichlorophenyl groups are attached onto the most reactive sites along the zigzag edges. The structure was confirmed by X-ray crystallographic analysis and its electronic properties were systematically investigated by both experiments and theoretical calculations. It exhibits an open-shell singlet ground state with a moderate diradical character (y0 =51.5 % by calculation) and a small singlet-triplet gap (ΔES-T =-2.5 kcal mol-1 by SQUID measurement). It displays global aromatic character, which is different from the smaller-size bisanthene analogue BA-CF3.

A Peri‐tetracene Diradicaloid: Synthesis and Properties