Synthesis,Polymorphism And Photoluminescence Of Bodipy Dyes

4-Methoxycarbonylphenyl-substituted BODIPY(boron-dipyrromethene)dyegives, in the solid state, three polymorphs. Possessing aunique combination ofimpressive spectroscopic featuresand flexibility with desired functionalities. Thespectroscopic characteristics of Bodipy dyes includestrong absorption cross sectionsin the visible to near-IR range with high extinction coefficients, large quantumyieldsand good solubility in organic solvents. In spiteof the absence of any strongintermolecular interactions in allcrystalline forms, the three polymorphs showdifferentphotoluminescence properties. This behavior highlights the importanceof moleculararrangements of the BODIPY moieties in the crystalline state in perturbing theirphotophysical propertiesA simple4-aniline boron-dipyrromethene (BODIPY) dye wasdeveloped as ahighly sensitive acidic pH fluorescent probe excitable with visible light based onphotoinduced electron transfer (PET) mechanism. The pH titration indicates thatthefluorescence intensity increases more than500-foldwithin the pH range of4.12-1.42with the pKavalue of3.24in methanolwater (1:1, v/v) solution, which isvaluable for studying strongly acidicconditions. Density functional theory (DFT)calculations10reproduce the fluorescence off-on behavior.1has also been used as afluorescent chemosensor for the visual detection of dissolved carbon dioxide (CO2)gas. The underlying mechanism of the sensing process is rationalized. This probe canbe recovered by bubbling nitrogen (N2) gas into CO2-treated solutions for over10cycles.