NBN- and BNB-Phenalenyls: the Yin and Yang of Heteroatom-doped π Systems.

Autor: Scholz AS; Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße 7, 60438, Frankfurt am Main, Germany., Massoth JG; Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße 7, 60438, Frankfurt am Main, Germany., Stoess L; Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße 7, 60438, Frankfurt am Main, Germany., Bolte M; Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße 7, 60438, Frankfurt am Main, Germany., Braun M; Institut für Physikalische und Theoretische Chemie, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße 7, 60438, Frankfurt am Main, Germany., Lerner HW; Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße 7, 60438, Frankfurt am Main, Germany., Mewes JM; Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich Wilhelms-Universität Bonn, Beringstr. 4, 53115, Bonn, Germany., Wagner M; Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße 7, 60438, Frankfurt am Main, Germany., Froitzheim T; Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich Wilhelms-Universität Bonn, Beringstr. 4, 53115, Bonn, Germany.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2024 May 14; Vol. 30 (27), pp. e202400320. Date of Electronic Publication: 2024 Mar 19.
DOI: 10.1002/chem.202400320
Abstrakt: NBN- and BNB-doped phenalenyls are isoelectronic to phenalenyl anions and cations, respectively. They represent a pair of complementary molecules that have essentially identical structures but opposite properties as electron donors and acceptors. The NBN-phenalenyls 1-4 considered here were prepared from N,N'-dimethyl-1,8-diaminonaphthalene and readily available boron-containing building blocks (i. e., BH 3 ⋅SMe 2 (1), p-CF 3 -C 6 H 4 B(OH) 2 (2), C 6 H 5 B(OH) 2 (3), or MesBCl 2 /iPr 2 NEt (4)). Treatment of 1 with 4-Me 2 N-2,6-Me 2 -C 6 H 2 Li gave the corresponding NBN derivative 5. The BNB-phenalenyl 6 was synthesized from 1,8-naphthalenediyl-bridged diborane(6), PhNH 2 , and MesMgBr. A computational study reveals that the photoemission of 1, 4, and 5 originates from locally excited (LE) states at the NBN-phenalenyl fragments, while that of 2 is dominated by charge transfer (CT) from the NBN-phenalenyl to the p-CF 3 -C 6 H 4 fragment. Depending on the dihedral angle θ between its Ph and NBN planes, compound 3 emits mainly from a less polar LE (θ >55°) or more polar CT state (θ <55°). In turn, the energetic preference for either state is governed by the polarity of the solvent used. An equimolar aggregate of the NBN- and BNB-phenalenyls 3 and 6 (in THF/H 2 O) shows a distinct red-shifted emission compared to that of the individual components, which originates from an intermolecular CT state.
(© 2024 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)
Databáze: MEDLINE
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