8th Position BODIPY Chemistry

Abstract

The projects examined in this dissertation demonstrate how the meso substituents N and S lone pair-BODIPY core interaction influence the chemistry and properties of BODIPY fluorophores. Three objectives were completed experimentally and computationally. In the first project the meso amide substituent delocalizes the nitrogen lone pair into the carbonyl, preventing a hemicyanine resonance that causes blue emission in 8-amino-BODIPYs. The second and third projects substituting aniline or phenylthiol derivatives onto the 8^th position, respectively. The aniline and phenylthio lone pair interaction with the BODIPY core can be modulated by electron-donating (ED) or –withdrawing (EW) moieties placed para on the aryl group. Electron-donating derivatives hypsochromically shift the absorbance from the parent fluorophore, 8-[(C₆H₄)NH]BODIPY or 8-[(C₆H₄)S]BODIPY; while electron withdrawing derivatives bathochromically shift the absorbance and fluoresce. The EW substituents result in significant reduction of the lone pair delocalization to the BODIPY core and remove the normal co-planarity of the N and BODIPY core, both experimentally and computationally. The fourth project aimed to quickly and inexpensively synthesis a BODIPY to engage in thiolene-click-chemistry (TCC). The synthesis 8-(HS(CH₂)₃NH₂)BODIPY was accomplished from the reaction of 8-(MeS)BODIPY with HS(CH₂)₃NH₂, but in poor yields that prevented detailed study. However, the major product was the interesting disulfide 8-(MeSS(CH₂)₃NH₂)BODIPY which we characterized completely, and opens a realm of new chemistry to be explored.