Synthesis of the Core Compound of the BODIPY Dye Class: 4,4′-Difluoro-4-bora-(3a,4a)-diaza-s-indacene

Abstract

We report the synthesis and characterization of the missing reference core compound 4,4-Difluoro-4-bora-(3a,4a)-diaza-s-indacene 1 of the BODIPY fluorescent dye class. The compound exhibits a fluorescence lifetime of 7.2 ns and has a high photostability.

Effect of the substitution position (2, 3 or 8) on the spectroscopic and photophysical properties of BODIPY dyes with a phenyl, styryl or phenylethynyl group

“…In both cases, abs(max) is more red-shifted in the more polarizable solvents toluene and chlorobenzene. In contrast, the values of abs(max) of 8-Ph (with a phenyl substituent at the meso-position) are blue-shifted in relation to those of 2-Ph and 3-Ph and are close to those of unsubstituted boron dipyrromethene, 3,[22][23][24] ranging from 489 nm in acetonitrile to 497 nm in toluene and chlorobenzene: the solvent dependence correlating with the refractive index. This absorption energy range is in good agreement with that of other BODIPYs substituted at the mesoposition with a weak electron acceptor or donor.…”

“…19 Boron dipyrromethenes, modified at the meso-position with strong electron withdrawing groups, possess large red shifts, [20][21] because the LUMO is highly stabilized 3 compared to unsubstituted BODIPY. 3,[22][23][24] In contrast, electron donating groups at the meso-position cause a blue-shift in the absorption and emission spectra, while keeping high fluorescence quantum yields and lifetimes. [25][26][27][28] Certain modifications at the meso-position may result in almost nonfluorescent compounds, as for meso-alkenyl- 29 or meso-formylBODIPYs.…”

Why Do TD-DFT Excitation Energies of BODIPY/Aza-BODIPY Families Largely Deviate from Experiment? Answers from Electron Correlated and Multireference Methods

“…Difluoro-boron-triaza-anthracene (6), BF 2 linked green fluorescent protein (GFP) chromophore analogs (7) and (9), and the BF 2 linked GFP chromophore itself (8) are also in the set of structures considered in this work; for the benchmark study on the GFP chromophore itself see the work of Uppsten and Durbeej. 85 In addition, substituted complexes of 1 and 6 were chosen to show the impact of substitution of both electron donor (amino (10) and thio (14)) and acceptor (cyano (11 and 12)) groups on the photophysical properties of these compounds. To investigate the effect of replacing the fluorine atoms and fusing different carbocyclic rings, compounds 13, 15, and 16 were chosen to be examined.…”

“…while the cyano(11) and thio(14) groups increase this value 84 (76) and 23 (−3.8), respectively. Attaching five-and six-membered rings to 1 results in formation of 15 and 16 which also show a bathochromic shift for the maximum absorption.…”

Isoindole‐BODIPY Dyes as Red to Near‐Infrared Fluorophores

“…BODIPY 3 aa in dichloromethane exhibits a vivid pink colour under ambient light and bright red colour when irradiated with a hand‐held UV lamp, whereas 3 ab , 3 ac and 3 ad show red, vivid blue and blue absorption colours and bright red fluorescence emission (Figure 4). In comparison with parent BODIPY A 15 (Figure 1) a significant spectral red‐shift (63 and 87 nm in absorption and emission, respectively) was observed for BODIPY 3 aa with good bright fluorescence emission ( ϕ =0.80) at 599 nm; this indicates enhancement in the π electron delocalisation due to the existence of uncoordinated third pyrrole unit. These excellent optical properties, especially the high quantum yield, were also observed in other solvents studied ( ϕ hexane =0.84, ϕ toluene =0.69, ϕ THF =0.81, ϕ MeCN =0.81, and ϕ MeOH =0.96).…”