α-Monoacylated and α,α′- and α,β′-Diacylated Dipyrrins as Highly Sensitive Fluorescence “Turn-on” Zn²⁺ Probes

Abstract

With the purpose of developing readily synthesized CHEF (chelation-enhanced fluorescence) type Zn(2+) probes with relatively simple molecular structures and excellent sensing behavior, p-anisoyl chloride was used for the acylation of 5-(pentafluorophenyl)dipyrromethane. Interestingly, the α,β'-diacylated product PS2 with a unique substitution mode was obtained in high yield in addition to the normal α-substituted mono- and diacylated products PS1 and PS3. Further oxidation of PS1-PS3 afforded dipyrrins S1-S3. Crystal structure and (1)H NMR measurements of S2 demonstrate the existence of a pure tautomer, which is consistent with DFT calculations. S1-S3 show highly Zn(2+) selective "turn-on" fluorescence based on a CHEF mechanism by the formation of 2:1 (probe:metal) Zn(2+) complexes. The emission colors can be easily tuned from green to red by changing the dipyrrin substitution modes. Furthermore, these probes demonstrate fast responses and wide applicable pH ranges. Among them, S2 shows the highest Zn(2+) sensitivity, with a detection limit of 4.4 × 10(-8) M.

Novel Alkoxy‐Substituted Dipyrrins and Near‐IR BODIPY Dyes—Preparation and Photophysical Properties

“…The fairly large Stokes shifts of all dipyrrins in the range of 2000–2700 cm −1 make these compounds interesting for many applications . To our surprise, only a few studies on the fluorescence of dipyrrins are reported …”

Facile Preparation of 2,6‐Pyridinedicarb­oxylic Acid Protected Gold Nanoparticles with Sensitive Chromium‐Ion Sensing and Efficient Catalysis

“…[26] Therefore, an accurate and reliable method for the determination of chromium ions is important. The detection of chromium ions in water samples has been performed by a variety of techniques, including electrothermal atomic absorption spectrometry, [27,28] atomic absorption spectrometry, [29] fluorescence spectroscopy, [30][31][32] potentiometric membrane sensing, [33] and electrolysis. [34] Among the many detection methods, colorimetric detection based on gold nanoparticles is particularly attractive for point-of-use applications owing to its low cost, speed, and especially ease of readout (even with the naked eye).…”

An off–on fluorescent probe based on maleimide for detecting thiols and its application for bioimaging

“…Subsequent data analysis revealed an excellent linear relationship (R = 0.999) between the relative fluorescence intensity at 502 nm and the Hcy concentration (0-30 mol/L). The detection limit for Hcy, based on the definition by IUPAC (CDL = 3 Sb/m) [54][55][56][57][58][59], was calculated to be 0.017 mol/L. Similarly, the detection limits for Cys and GSH were evaluated to be 0.043 mol/L and 0.053 mol/L, respectively (Fig.…”