Multichannel-Emissive V-Shaped Boryl-BODIPY Dyads: Synthesis, Structure, and Remarkably Diverse Response toward Fluoride

Abstract

Three new V-shaped boryl-BODIPY dyads (1-3) were synthesized and structurally characterized. Compounds 1-3 are structurally close molecular siblings differing only in the number of methyl substituents on the BODIPY moiety that were found to play a major role in determining their photophysical behavior. The dyads show rare forms of multiple-channel emission characteristics arising from different extents of electronic energy transfer (EET) processes between the two covalently linked fluorescent chromophores (borane and BODIPY units). Insights into the origin and nature of their emission behavior were gained from comparison with closely related model molecular systems and related photophysical investigations. Because of the presence of the Lewis acidic triarylborane moiety, the dyads function as highly selective and sensitive fluoride sensors with vastly different response behaviors. When fluoride binds to the tricoordinate borane center, dyad 1 shows gradual quenching of its BODIPY-dominated emission due to the ceasing of the (borane to BODIPY) EET process. Dyad 2 shows a ratiometric fluorescence response for fluoride ions. Dyad 3 forms fluoride-induced nanoaggregates that result in fast and effective quenching of its fluorescence intensity just for ∼0.3 ppm of analyte (i.e., 0.1 equiv ≡ 0.26 ppm of fluoride). The small structural alterations in these three structurally close dyads (1-3) result in exceptionally versatile and unique photophysical behaviors and remarkably diverse responses toward a single analyte, i.e., fluoride ion.

Fluorescent Sensing of Fluoride in Cellular System

“…The binding constants were 1.4×10 5 M -1 , 1.0×10 5 M -1 and 2.2×10 5 M -1 , respectively. The selectivity toward F - was quite remarkable against other interfering species such as CN - 72 .…”

“…With polychromophoric systems, many borane-BODIPY dyads Probe 47~49 were synthesized. Their two functionalities could be replaced at two positions of phenyl spacer (position 1 and position 3) 72 . The two fluorescent chromophores were remarkably close due to the unique “V” shape structure.…”

Advanced applications of chemo‐responsive dyes based odor imaging technology for fast sensing food quality and safety: A review

“…As shown in Figure 2b, the substituents are grafted on the core of BODIPY, and they can be forced to separate from each other without affecting the properties of the chromophore. This prevents the π‐π stacking to form a conformationally restricted cyclic structure, enabling the fluorobarpyrrole compounds to have simple single‐conjugated chemical structures (Swamy et al., 2014). This kind of compound has absorption mostly in the red to near‐infrared regions.…”

A Benzodithiophene‐Based Fluorescence Probe for Rapid Detection of Fluoride Ion

“…Upon the addition of F  to the solution, the fluorescence intensity at 460 nm gradually decreased, and 40% of the fluorescence intensity was quenched. [37,38] Moreover, the Si-C and Si-F bond dissociation energies were different (69 and 141 kcal/mol, [1] respectively), it is likely that the Si-C bond was splited and the short wavelength fluorescent product was released with the reaction between compound 1 and F  , which is responsible for the fluorescence decreasing and blue shifting. At the same time, the fluorescence color also changed, which maybe stem from the deprotection of electron-donating TMS group by F  .…”