The Role of Electron‐Donating Subunits in Cross‐Linked BODIPY Polymer Films

Abstract

AbstractA new method for synthesizing cross‐linked 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacenes (BODIPYs) using a radical‐based thiol‐ene click reaction is developed. This method is simple, efficient, and cost‐effective, and it produces polymers with unique optical, electrochemical, and surface morphology properties. Significant blue shifts in absorption and photoinduced electron transfer in emissions are observed in the cross‐linked BODIPY thin films. Cross‐linking also leads to the restriction of conjugation, which results in the breakage of the terminal vinyl group, an increase in the oxidation potential, and a slight upshift in the HOMO position. As a result, the electrochemical band gap is widened from 1.88 to 1.94 eV for polymer bearing N,N‐dimethylamino‐BODIPY and from 1.97 to 2.02 eV for polymer bearing N,N‐diphenylamino‐BODIPY moieties. Monomer thin films form planar surfaces due to crystallinity, while amorphous cross‐linked BODIPY polymers form more rough surfaces. Additionally, photopatterning on the film surface is successfully performed using different patterned masks. This new method for synthesizing cross‐linked BODIPYs has the potential to be used in a variety of applications, including organic electronics, bioimaging, and photocatalysis.