Highly emissive planarized B,N-diarylated benzonaphthoazaborine compounds for narrowband blue fluorescence† † Electronic supplementary information (ESI) available: Experimental, photophysical and computational data, and NMR spectra. See DOI: https://doi.org/10.1039/d2ra05163j

ABSTRACT: Highly fluorescent blue emitters with high color purity are of great significance for optical applications. Herein, a series of planarized B,N-diarylated benzonaphthoazaborine compounds, namely, BzNp (1), BuBzNp (2), Bu2BzNp (3), Bu2BzMeNp (4), and Bu2BzBuNp (5), where electron-donating tBu and Me groups are differently introduced into the B-Ph, N-Ph, or benzoazaborine rings, are prepared and characterized. All compounds exhibit low-energy absorptions (λabs = 462–467 nm) and emissions (λPL = 472–478 nm) remarkably red-shifted compared with those found for the pristine dibenzoazaborine compound (404 and 415 nm, respectively). Although the expansion of π-conjugation in the azaborine ring by replacing one phenyl ring with a naphthyl ring is mainly responsible for the redshifts, the emission is also fine-tuned by attached alkyl groups, which have a greater impact on the B-centered LUMO level at the azaborine ring than at the B-Ph ring. The bandgap control and emission tuning are further supported by electrochemical and theoretical studies. Notably, blue to sky-blue fluorescence of all compounds exhibits unitary photoluminescence quantum yields, narrow full width at half maximum values (∼20 nm), and small Stokes shifts (∼11 nm), indicating strong emissions with high color purity. The incorporation of a naphthyl ring into the azaborine core led to blue to sky-blue fluorescence with unitary photoluminescence quantum yields, narrow full width at half maximum values, and small Stokes shifts.

SUBMITTER: Nguyen N 

PROVIDER: S-EPMC9580519 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature