Semester of Graduation

Fall 2025

Degree

Master of Science (MS)

Department

Chemistry

Document Type

Thesis

Abstract

This study explores the regioselective nitration of BODIPY dyes at the 2, 3- and 2,6-positions using nitronium tetrafluoroborate (NO₂BF₄), offering a high-yielding and mild synthetic route. The introduction of nitro groups significantly alters the dyes’ photophysical and self-assembly properties. Mono-nitrated BODIPYs exhibit hypsochromic shifts in absorption and emission spectra, increased dipole moments, enhanced Stokes shifts, and reduced molar absorptivity. In contrast, di-nitrated analogs show bathochromic shifts and decreased dipole moments in both ground and excited states. Spectroscopic characterization was performed using UV-vis and fluorescence spectroscopy, supported by density functional theory (DFT) calculations. Self-assembly behavior was investigated in polar (acetonitrile) and non-polar (toluene) solvents, revealing solvent-dependent fluorescence quantum yields and aggregation tendencies. Atomic force microscopy (AFM) confirmed aggregation in aqueous media and its absence in organic solvents. These findings demonstrate the tunability of BODIPY dyes through nitration and highlight their potential application as polarity-sensitive probes in diverse environments.

Date

10-31-2025

Committee Chair

Vicente Graca

Download

Share

COinS