12b,24b-Diborahexabenzo[a,c,fg,l,n,qr]pentacene: A Low-LUMO Boron-Doped Polycyclic Aromatic Hydrocarbon
Journal
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
Journal Volume
61
Journal Issue
8
Pages
e202115746
Date Issued
2022
Author(s)
Abstract
Herein we devise and execute a new synthesis of a pristine boron-doped nanographene. Our target boron-doped nanographene was designed based on DFT calculations to possess a low LUMO energy level and a narrow band gap derived from its precise geometry and B-doping arrangement. Our synthesis of this target, a doubly B-doped hexabenzopentacene (B2-HBP), employs six net C−H borylations of an alkene, comprising consecutive hydroboration/electrophilic borylation/dehydrogenation and BBr3/AlCl3/2,6-dichloropyridine-mediated C−H borylation steps. As predicted by our calculations, B2-HBP absorbs strongly in the visible region and emits in the NIR up to 1150 nm in o-dichlorobenzene solutions. Furthermore, B2-HBP possesses a very low LUMO level, showing two reversible reductions at −1.00 V and −1.17 V vs. Fc+/Fc. Our methodology is surprisingly selective despite its implementation of unfunctionalized precursors and offers a new approach to the synthesis of pristine B-doped polycyclic aromatic hydrocarbons. © 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH
Subjects
Aromaticity; Boron; Near infrared emitter; Pentacene; Polycycles
SDGs
Other Subjects
Boron; Energy gap; Mineral oils; B-doping; Boron-doped; Borylation; DFT calculation; Hydroboration; LUMO energy levels; Narrow bandgap; O-dichlorobenzene; Pentacenes; Visible region; Polycyclic aromatic hydrocarbons
Type
journal article