Details

Autor(en) / Beteiligte

• Menduti, Luigi
• Baldoli, Clara
• Manetto, Simone
• Bolte, Michael
• Lerner, Hans‐Wolfram
• Longhi, Giovanna
• Villani, Claudio
• Licandro, Emanuela
• Wagner, Matthias

Titel

(BO)2‐Doped Tetrathia[7]helicene: A Configurationally Stable Blue Emitter

Ist Teil von

• Angewandte Chemie (International ed.), 2023-01, Vol.62 (5), p.e202215468-n/a

Ort / Verlag

Germany: John Wiley and Sons Inc

Erscheinungsjahr

2023

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Helicenes combine two central themes in chemistry: extended π‐conjugation and chirality. Hetero‐atom doping preserves both characteristics and allows modulation of the electronic structure of a helicene. Herein, we report the (BO)2‐doped tetrathia[7]helicene 1, which was prepared from 2‐methoxy‐3,3′‐bithiophene in four steps. 1 is formally derived by substituting two (Mes)B−O moieties in place of (H)C=C(H) fragments in two benzene rings of the parent tetrathia[7]helicene. X‐ray crystallography revealed a dihedral angle of 50.26(9)° between the two terminal thiophene rings. The (P)‐/(M)‐1 enantiomers were separated by chiral HPLC and are configurationally stable at room temperature. The experimentally determined enantiomerization barrier of 27.4±0.1 kcal mol−1 is lower than that of tetrathia[7]helicene (39.4±0.1 kcal mol−1). The circular dichroism spectra of (P)‐ and (M)‐1 show a perfect mirror‐image relationship. 1 is a blue emitter (λem=411 nm) with a photoluminescence quantum efficiency of ΦPL=6 % (cf. tetrathia[7]helicene: λem≈405 nm, ΦPL=5 %). A BO‐doped thiahelicene has been synthesized by a four‐step procedure and its optoelectronic and chiroptical properties investigated. The incorporation of two B−O bonds into the tetrathia[7]helicene framework has resulted in a configurationally stable (ΔGenant≠=27.4±0.1 kcal mol−1) blue emitter (ΦPL=6 %).