Sulfur‐Bridged BODIPY DYEmers

Abstract

Reactions of BODIPY monomers with sulfur nucleophiles and electrophiles result in the formation of new BODIPY dimers. Mono- and disulfur bridges are established, and the new dyestuff molecules were studied with respect to their structural, optical, and electrochemical properties. X-ray diffraction analyses reveal individual angulated orientations of the BODIPY subunits in all cases. DFT calculations provide solution conformers of the DYEmers which deviate in a specific manner from the crystallographic results. Clear exciton-like splittings are observed in the absorption spectra, with maxima at up to 628 nm, in combination with the expected weak fluorescence in polar solvents. A strong communication between the BODIPY subunits was detected by cyclic voltammetry, where two separated one-electron oxidation and reduction waves with peak-to-peak potential differences of 120-400 mV are observed. The qualitative applicability of the exciton model by Kasha for the interpretation of the absorption spectral shape with respect to the conformational state, subunit orientation and distance, and conjugation through the different sulfur bridges, is discussed in detail for the new BODIPY derivatives. This work is part of our concept of DYEmers, where the covalent oligomerisation of BODIPY-type dye molecules with close distances is leading to new functional dyes with predictable properties.

Synthesis, structure, and spectral, electrochemical and fluoride sensing properties of meso-pyrrolyl boron dipyrromethene

“…It has been observed a splitted absorption band in recently reported closely linked bis BODIPY systems [29][30][31][32] which was attributed to excitonic interactions that depends on relative orientation and distance between the two BODIPYs. It has been observed a splitted absorption band in recently reported closely linked bis BODIPY systems [29][30][31][32] which was attributed to excitonic interactions that depends on relative orientation and distance between the two BODIPYs.…”

New Two-Photon Absorbing BODIPY-Based Fluorescent Probe: Linear Photophysics, Stimulated Emission, and Ultrafast Spectroscopy

“…Purification by flash column chromatography using 1.0% methanol/CH 2 Cl 2 provided 7 as an off-white solid (6.34 g, 94%). 1 …”

“…The crude mixture was purified by flash column chromatography using 3.5% methanol/CH 2 Cl 2 , producing 1 as a purple solid (1.11 g, 77%). 1 2.2. Linear Spectroscopic Measurements and Instrumentation.…”

“…In this work, we present the synthesis of a new 2PA BODIPY-based fluorescence probe, 4,4-difluoro-8-(4-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}phenyl)-1,3,5,7-tetramethyl-2,6-di[ (9,9-di{2-[2-(2-methoxyethoxy)ethoxy]ethyl}-9H-fluoren-2-yl)ethynyl]-4-bora-3a,4a-diaza-s-indacene (1), and a comprehensive description of its linear spectroscopic, photochemical, and nonlinear optical properties, including 2PA and stimulated emission cross section measurements, femtosecond transient absorption pump−probe spectroscopy, and one-and twophoton pumped superluminescence. Probe 1 is a conjugate of BODIPY and fluorene moieties through triple bonds.…”

Thiocyanation of BODIPY dyes and their conversion to thioalkylated derivatives

“…5 To the best of our knowledge, thiocyanatosubstituted boron dipyrrins have not been previously reported, although they can be considered starting materials for BODIPY sulfides. [6][7][8][9][10] For this study, ten BODIPYs (Table 1) were synthesized using established procedures [11][12][13][14][15][16][17][18] and were used as starting materials for further reactions. …”