Synthesis And Properties Of NIR Aza-BODIPYs With Aryl And Alkynyl Substituents On The Boron Center

Among the recent twenty years, Aza-BODIPY(eg. compd.1) as a family offluoresencence dyes has been attracting increasing interest. Aza-BODIPYs possesses distinctfluorescence characters, such as long absorption and emission wavelength, high molar extinctioncoefficient, high photostability, high stability at physiological conditions and so on. Modificationson the structures to improve their fluorescent performance, have led to potential applications inchemosensor, fluorescent switch, photosencitizer of photodynamic therapy, controllablefluorescence chemosensor and near infrared fluorescent probe and so on.Based on the parent compound Aza-BODIPY1, three series of Aza-BODIPY dyes weredesigned and synthsized. F-Aza-BODIPY as one of the most studied Aza-BODIPY dye wasselected as our target family. The modifications of1on boron atom were very straight forward. C-and E-Aza-BODIPYs can be made through nucleophilic attack of Grignard reagent. During thepreparation, by means of controlling the equivalence of Gridard reagent over Aza-BODIPY,products2-4can be obtained. Aza-BODIPY with two different subsitutients on boron atom4canbe obtained by judicious control of the equivalence of two different Gridard reagents.To better understand the discrepancy of structure and characteristic between the targetproduct and parent product, UV-Visible absorption and fluorescence spectra, stability underdifferent solutions of pH1-14, cyclic voltammetry of electrochemistry were measured; thestructures of compounds were analyzed by X-ray single crystal diffraction; Fluorescencemicroscope imaging was also carried out.