Color Tuning of Polyfluorene Emission with BODIPY Monomers

Abstract

Three fluorescent conjugated copolymers, comprised of alternating fluorene and BODIPY units in the main chain, have been prepared by palladium-catalyzed Suzuki polymerization of 9,9-dihexylfluorene-2,7-diboronic acid with each of three different 2,6-diiodo-substituted BODIPY monomers. The copolymers were characterized using FT-IR spectroscopy, UV-vis spectroscopy, photoluminescence (PL), and molecular weight studies. Low-band gap BODIPY comonomers are effective in expanding the emission wavelength to the orange region because of significant extension of π-conjugation and have significantly enhanced fluorescent intensity with fluorescent quantum yield of up to 85% in methylene chloride solution. The copolymers show absorption maxima between 547 and 557 nm and emission maxima between 585 and 588 nm in methylene chloride solutions. The copolymers possess high molecular weight, good solubility and readily dissolve in common organic solvents such as THF, CH 2 Cl 2 , CHCl 3 , and toluene. The copolymers display sensitive fluorescent responses to fluoride and cyanide anions through their multivalent interactions while they do not respond to chloride, bromide, and iodide anions.

4,4′-Difluoro-4-bora-3a,4a-diaza-s-indacenes (BODIPYs) as components of novel light active materials

“…50). 125 As seen in previous examples, the extension of the p-system delocalisation results in a bathochromic shift in the polymer absorption relative to the monomer. Electron-donating methoxy groups have a slight effect on the absorption, but there is an even lesser effect on the emission (98 and 99), while the methyl groups cause an increase in fluorescence quantum yield (100).…”

Spectroscopic, computational modeling and cytotoxicity of a series of meso-phenyl and meso-thienyl-BODIPYs

“…Eleven meso -aryl BODIPYs ( 1 – 11 ) were synthesized from commercially available 2,4-dimethylpyrrole and the corresponding aryl aldehyde, following a three-step one-pot procedure often used for BODIPY synthesis 46 (Scheme 1). First, two pyrrole units were condensed with the aryl aldehyde in dichloromethane in the presence of BF 3 ·OEt 2 , then the resulting dipyrromethanes were oxidized using DDQ and finally the dipyrromethenes were complexed with excess BF 3 ·OEt 2 under basic conditions.…”

Synthesis and spectroscopic properties of β,β′-dibenzo-3,5,8-triaryl-BODIPYs

“…31 The introduction of a 8-(3,5-dimethoxy)phenyl group in place of a 8-phenyl caused negligible shifts in the absorption and emission wavelengths, and slightly decreased the quantum yield, probably because of increased non-radiative decay to the ground state. 32 …”

“…20 Among these, the Pd(0)-catalyzed Suzuki coupling reactions are particularly convenient 32 due to the variety of commercially available boronic acids and the ready availability of 3,5-dichloro- and 3,5-dibromo-BODIPYs. Previously reported Suzuki couplings on 3,5-dichloro-BODIPYs require microwave irradiation, and produce the target BODIPYs in yields up to 68%.…”