BODIPY-based Sulfoxide:Synthesis, Photophysical Characterization And Application

BODIPYs (boron-dipyrromethene dyes) are of special interest as chromophores due to their valuable photophysical characteristicssuch, such as intense fluorescence quantum yields, sharp absorption and fluorescence emission spectra, and high photo-and chemostability. Furthermore, the parent structure of BODIPY is easy to modify chemically for the preparation of various derivatives. Consiquently, the preparation of sophisticated BODIPY dyes resolving specific problems have been established.Four BODIPY dyes bearing a sulfur containing function at the3-position are reported. The3-benzylthio compound shows spectroscopic features of the classical BODIPY platform, showing minor solvent dependent spectral shift, a relative small Stokes shift and a high fluorescence quantumyield. Oxidation of the sulfur atom to the sulfoxide leads to a large hypsochromic shift in absorption and emission. We also demonstrated that the sulfoxide derivative can be used as a ratiometric fluorescent chemodosimeter for highly toxic benzenethiols in aqueous media. In this dosimeter the sulfoxide is chemospecifically reduced by benzenethiols to obtain the original oxidation state of the sulfur atom, accompanied with a drastic ratiometric fluorescence response. Furthermore, the probe features excellent selectivity over other competing analytes, moderate signal response times and a good linearity range for quantification. All these features render the sensor suitable for detection of benzenethiols in environmental settings.Hypochlorous acid (HClO) is one of the biologically significant reactive oxygen species. Abnormal levels of HOCl are implicated with many kind of pathology. Therefore, the detection of HOCl is on demand. We here reported a BODIPY-based probe for HOCl, which containg2-mercaptoethanol at the3-position. This probe features a marked absorption and emission blue-shift upon oxidation with HOCl to give sulfoxide, enabling the highly selective detection and is promising for applications.There is great attention to the engineering of BODIPYs. We here also obtained a series of BODIPYs and evaluated their photophysical properties. A common strategy has been introduced to tune the photophyscial properties upon changing electron withdrawing effect of the substituent to electron donating.