Water‐soluble fluorescent polymers that respond to singlet oxygen

Abstract

Although acenes with more than three fused rings can both fluoresce efficiently and react with singlet oxygen ( 1 O 2 ) rapidly, their hydrophobic nature presents a challenge to their use in aqueous environments. Herein we report a series of fluorescent, water-soluble random copolymers that each comprise (oligoethylene glycol) methacrylate (OEGMA) and one of several diarylacene methacrylates, including a tetracene methacrylate and a tetraceneothiophene methacrylate. Exposure to 1 O 2 in water oxidizes the pendant acenes, resulting in diminution of their fluorescence intensities. The observed rate of oxidation of the tetracene-containing polymers compares favorably with a commercial 1 O 2 -sensitive dye. Polymers that also include energy-donating coumarin side chains show ratiometric fluorescence changes in response to 1 O 2 .

Reductive Aromatization/Dearomatization and Elimination Reactions to Access Conjugated Polycyclic Hydrocarbons, Heteroacenes, and Cumulenes

“…Despite being amongst the first reported procedures to form substituted pentacenes, reductive aromatization using KI in acetic acid is rarely reported in the literature. Only a few examples, including the synthesis of a tetracene by Thomas and co‐workers and the synthesis of 6,13‐diarylated pentacene 93 by Swager and Ohira, are known (Scheme ). It should be noted that Swager and co‐workers observed degradation of the product when the reaction was conducted under ambient light, a common occurrence for reactions presented in this section.…”

Regioselective Synthesis of 5-Propyl-2-((trityloxy)methyl)thiophene-3-carbaldehyde

“…Alkylated thiophene-3-carbaldehyde is a widely used building block for organic synthesis of a myriad of materials with multiple applications. It has been used as the key starting material for organic field-effect transistors [1-5], glucagon antagonist [6], inhibitors of D-amino acid oxidase [7], dopamine 1 agonist ABT-431 (Figure 1) [8,9], and water-soluble fluorescent polymers [10]. Due to their strong luminescence properties, thiophene-based compounds have also been used for dye-sensitized organic solar cells and light emitting devices [11] as well as nonlinear optical chromophores [12].…”

Red-Emitting, Acene-Doped Conjugated Polymer Nanoparticles that Respond Ratiometrically to Photogenerated 1O2

“…The literature contains a number of 1 O 2 -reactive dyes for which the competitiveness of radiative relaxation of the dye increases due to an interruption of electron transfer quenching upon endoperoxide formation. Our own group has developed polymeric materialsorganic and water-soluble polymers, , CP films, and most recently CP nanoparticles that show ratiometric fluorescent responses to photogenerated 1 O 2 due to an interruption of energy transfer. , In addition, the modular nature of doping such nanoparticles with a range of acenes with different spectral properties and reactivities allows for broad tuning of the resulting responses …”