Theobromine and direct arylation: a sustainable and scalable solution to minimize aggregation caused quenching

Abstract

Green chemistry and a natural product together provide a cost-effective, safe and scalable solution to create luminophores with suppressed aggregation quenching in organic semiconductors.

Advances in applying C–H functionalization and naturally sourced building blocks in organic semiconductor synthesis

“…60,61 Our group also reported small molecule organic luminophores with high photoluminescence quantum yields prepared by direct arylation, which will be detailed in the later section. 62 2.1.2 Oxidative C-H/C-H coupling. Oxidative C-H/C-H coupling has received a lot of attention in the organic materials space since its initial report by Fagnou et al 63 In terms of atom economy, it is superior to direct arylation since no pre-halogenation step is needed.…”

“…This worked to suppress aggregation caused quenching (ACQ) in pyrene's solid state (Scheme 16a). 62 The resulted pyrene-theobromine thin films exhibited a photoluminescence quantum yield (PLQY) of almost 100%. After that, we synthesized theobromine-based organic dyes (Theo-green and Theo-red) (Scheme 16b) using alkylated theobromine via direct arylation.…”

Naturally Derived Organic Dyes for LED Lightings of High Color Rendering and Fidelity Index

“…Reactions were run under N2 atmosphere using standard Schlenk techniques and detailed synthesis procedures are described below. Theo8 [1] and 4,9-dibromonaphtho[2,3c][1,2,5]selenadiazole [2] were prepared according to literature procedures. NMR was taken with Bruker 500 MHz spectrometer.…”

Naturally Derived Organic Dyes for LED Lightings of High Color Rendering and Fidelity Index

“…[ 2 ] However, the prices of industrially available fluorescent dyes are significantly higher than inorganic phosphors due to their complicated structures that require long synthetic routes and explosive and toxic reagents. [ 7 ] In addition, the light converting materials should have high photoluminescent quantum yields (PLQYs) to improve the energy efficiencies of LED devices. For example, cerium doped yttrium aluminum garnet (YAG:Ce) is the most applied REE phosphor in LED lighting partially because it has PLQYs of around 90%.…”

“…Recently, our group reported several organic dyes with broad‐band emissions from theobromine, an abundant natural product originally found in cacao beans. [ 7 ] The syntheses of these theobromine dyes are streamlined and eco‐friendly. The resultant dyes possess high PLQYs when blended with an inexpensive industrial polymer, poly(styrene‐butadiene‐styrene) (SBS), that serves as the host matrix to enable device integration.…”