Furan-Containing Singlet Oxygen-Responsive Conjugated Polymers

Abstract

This paper describes conjugated polymers with 2,5diarylfuran moieties as nonconjugated pendants that respond to singlet oxygen ( 1 O 2 ) by fluorescence quenching. By oxidizing the diarylfurans to more electron-poor moieties such as enol esters, singlet oxygen causes poly(fluorene-co-phenylene) conjugated backbones to donate excited electrons to the oxidized pendants, resulting in quenching of up to 93% of the initial fluorescence of the polymer, while an analogous furan-substituted poly(phenylene−ethynylene) showed no quenching upon furan− 1 O 2 reaction. All furan derivatives reacted rapidly with 1 O 2 (k = 10 7 −10 8 M −1 s −1 ), with more electron-poor furans reacting more slowly, but yielding more efficient fluorescence quenching, than less electron-poor furans.

Furans and singlet oxygen – why there is more to come from this powerful partnership

“…This is turning out to be true for 1 O 2 reactions with furan which are now starting to pop up all over the place -used in entirely novel ways in a diverse range of new research fields. For example; in sequence specific DNA/RNA cross-linking triggered by light (for achieving artificial control of gene expression, Scheme 29), 116 protein-RNA cross-linking, 117 1 O 2 -responsive conjugated polymers (new materials), 118 fluorescent probes for detection of intracellular oxygen, 119 the sustainable synthesis of herbicides, 120 and the sustainable synthesis of new surfactants. 121…”

Highly Efficient Singlet Oxygen Generation and High Oxidation Resistance Enhanced by Arsole-Polymer-Based Photosensitizer: Application as a Recyclable Photooxidation Catalyst

“…Such a sophisticated design is needed for highly efficient 1 O 2 generation. In addition, photosensitizers containing a conjugated backbone or heteroatom are often transformed into other chemical species because of the high oxidizability of the generated 1 O 2 . ,− This phenomenon potentially precludes the 1 O 2 generation capability of photosensitizers. From a practical application perspective, permanent 1 O 2 generation and high durability under an oxidation condition are necessary.…”

Designing photoluminescent molecular probes for singlet oxygen, hydroxyl radical, and iron–oxygen species

“…To maximize energy transfer, poly(phenylene-co-uorene) tethering 5,12-diarylated tetracene (6) and 2,5-diphenylfurane units (9) were prepared. 51,52 In addition to the acene derivatives, dienyl heterocycles can also serve as effective 1 O 2 traps. Tang and co-workers attached histidine onto a NIR-uorescent cyanine dye (8).…”