The fluorine effect: photophysical properties of borondipyrromethene (bodipy) dyes appended at the meso position with fluorinated aryl groups

Abstract

A small series of partially alkylated Bodipy dyes were prepared containing F n -aryl (n = 1,2,3,5) groups at the meso position. The effect of increasing the number of fluorines, and their position in the aryl ring, on the electrochemical and photophysical properties of the dyes is discussed. The highly electron withdrawing pentafluoroaryl group makes reduction of the Bodipy segment especially easy when compared to the basic phenylene derivative. High quantum yields of fluorescence in toluene solution are seen for derivatives with fluorine(s) substituted in the ortho position of the meso aryl group. This effect is also mirrored in the fluorescence lifetimes for the molecules. Pressure dependent fluorescence measurements carried out reveal subtle differences in the behaviour for the series of Bodipy derivatives.

Highly Fluorescent Magnetic Nanobeads with a Remarkable Stokes Shift as Labels for Enhanced Detection in Immunoassays

“…The donor (D) and acceptor (A) dyes incorporate a pentafluorophenyl substituent in the meso position. Such highly electron withdrawing unit confers BODIPY dyes a higher fluorescence quantum yield, longer emission lifetime, and bathochromic shifts in absorption and emission maxima with respect to the parent meso ‐phenyl derivative . To accomplish an efficient FRET process, we also have to keep in mind that the selected dyes must display the largest possible spectral overlap between the emission of D and the absorption of A.…”

Carbazole substituted BODIPY dyes: Synthesis, photophysical properties and antitumor activity

“…According to literature, the carbazole ring systems are easily functionalized and covalently linked to other molecules [30]. In particular, carbazole undergo Vilsmeier-Haack formylation to obtain an appropriate carbazole carbaldehyde using dimethyl formamide and phosphoryl chloride [29]. This reaction therefore provides a ready entry to suitable aldehyde precursors for the BODIPY synthesis.…”

“…This reaction therefore provides a ready entry to suitable aldehyde precursors for the BODIPY synthesis. The first step was the formylation of 9-ethylcarbazole 1 by Vilsmeier-Haack conditions using phosphoryl chloride and dimethyl formamide to get mono-and diformyl carbazoles 2 and 3 [29]. With the 9-ehtyl-9H-carbazole-3-carbaldehyde (2) and 9-ehtyl-9H-carbazole-3,6-dicarbaldehyde (3) in hand, it was of interest to use 9-ehtylcarbazole-3-carbaldehyde (2) as a monomeric model for the preparation of mono-BODIPY carbazole before extending the chemistry to bis-BODIPY carbazole.…”

“…The synthesis procedure of compound 6 was as follows based on literature with a minor revision [29] (Scheme 1).…”

Crystal structure of 5,5-difluoro-10-(4-fluorophenyl)-1,3,7,9-tetramethyl-5H-4l4,5l4-dipyrrolo[1,2-c:2′,1′-f][1,3,2]diazaborinine - a Z′ = 3 structure, C19H18B2F3N2

“…The title compound was synthesized according to the literature procedures [4,5]. The colorless crystals of the title compound were obtained by slow evaporation of a dichloromethane solution at room temperature.…”