Benzodipyrrole‐based Donor–Acceptor‐type Boron Complexes as Tunable Near‐infrared‐Absorbing Materials

Abstract

Benzodipyrrole-based donor-acceptor boron complexes were designed and synthesized as near-infrared-absorbing materials. The electron-rich organic framework combined with the Lewis acidic boron co-ordination enabled us to tune the LUMO energy level and the HOMO-LUMO gap (i.e.,the absorption wavelength) by changing the organic acceptor units, the number of boron atoms, and the substituents on the boron atoms.

4,7‐Bis[3‐(dimesitylboryl)thien‐2‐yl]benzothiadiazole: Solvato‐, Thermo‐, and Mechanochromism Based on the Reversible Formation of an Intramolecular B−N Bond

“…Recently, Ingleson and co‐workers reported BT derivatives with intramolecular B−N coordination bonds as far‐red/near‐infrared (NIR)‐emitting materials . Focused on the structures of such boryl‐substituted C=N‐containing π systems, the boryl‐substituted BT unit has major strain for the formation of an intramolecular B−N bond relative to that in quinoxaline derivatives (Figure a) . The introduction of steric bulkiness into boryl‐substituents, for example, by using the Mes 2 B group (Mes=2,4,6‐Me 3 C 6 H 2 ), in such boryl‐substituted BT units can be expected to induce reversibility for the formation of B−N coordination bonds.…”

“…[23] Focused on the structures of such boryl-substituted C=N-containing p systems, the boryl-substituted BT unit has major strain for the formation of an intramolecular BÀNb ond relative to that in quinoxalined e-rivatives ( Figure 1a). [25] The introduction of steric bulkiness into boryl-substituents, for example, by using the Mes 2 Bg roup (Mes = 2,4,6-Me 3 C 6 H 2 ), in such boryl-substituted BT units can be expected to induce reversibility fort he formationo fB ÀN coordination bonds. Based on this idea, we designed and synthesized Mes 2 B-substituted BT derivative 1 (Figure1b).…”

π-Extended Ladder-Type Conjugated Polymers via BN-Annulation

“…The synthetic routes to the target cLPs PolyBN-1 and PolyBN-2 are depicted in Scheme 1. The key monomer 2,5-dibromo-N,N-bis(2-hexyldecyl)benzene-1,4-diamine (2) was initially synthesized in 65% isolated yield, by attaching alky side chains to the amino groups of 2,5-dibromobenzene-1,4-diamine (1) 47 through typical nucleophilic substitution reaction. 2,5-Bis(trimethylstannyl)thieno [3,2-b] thiophene (3) and 1,1'- [4,8-…”

B←N Coordination: From Chemistry to Organic Photovoltaic Materials

“…Nakamura et al conducted borylation reactions on benzodipyrrole‐quinoxaline (50a) and benzodipyrrole‐benzothiadiazole (51a) chelates, respectively, leading to a series of anti‐ladder‐type boron complexes 50b‐d and 51b‐d. [ 100 ] Introducing boron into the parent precursors shifted the absorption from visible region to NIR region up to 1100 nm. Moreover, the absorption and energy levels were tuned by changing B numbers and installing fluorines on the diarylboron.…”