A General and Air‐tolerant Strategy to Conjugated Polymers within Seconds under Palladium(I) Dimer Catalysis

Abstract

While current M0/MII based polymerization strategies largely focus on fine‐tuning the catalyst, reagents and conditions for each and every monomer, this report discloses a single method that allows access to a variety of different conjugated polymers within seconds at room temperature. Key to this privileged reactivity is an air‐ and moisture stable dinuclear PdI catalyst. The method is operationally simple, robust and tolerant to air.

Photocontrolled Synthesis of n‐Type Conjugated Polymers

“…Literature reports of “transition‐metal‐free” cross‐coupling reactions inevitably must account for the high catalytic activity of Ni and Pd, which can promote reactions even at ppm levels . Inductively coupled plasma mass spectrometry (ICP‐MS) of crude reaction mixtures showed <2 ppm Ni and Pd.…”

“…Literature reports of "transition-metal-free" cross-coupling reactions inevitably must account for the high catalytic activity of Ni and Pd, which can promote reactions even at ppm levels. [38][39][40][41][42] Inductively coupled plasma mass spectrometry (ICP-MS) of crude reaction mixtures showed < 2ppm Ni and Pd. Dark control reactions doped with ppm levels of nickel showed that > 50 ppm of nickel was required to achieve comparable reactivity to the photoinduced polymerization (Table S13).…”

Air‐tolerant poly(3‐hexylthiophene) synthesis via catalyst‐transfer polymerization

“…Recognizing this challenge, several recent papers have described a more 'user‐friendly' conjugated polymer synthesis, in which the polymerization is performed in air 18,19 . For example, Kanabara and coworkers reported an oxygen‐ and moisture‐tolerant synthesis of thienopyrroledione‐based conjugated polymers through a step‐growth direct arylation polycondensation, wherein refluxing conditions effectively deoxygenated the solution 18,20 .…”

“…For example, Kanabara and coworkers reported an oxygen‐ and moisture‐tolerant synthesis of thienopyrroledione‐based conjugated polymers through a step‐growth direct arylation polycondensation, wherein refluxing conditions effectively deoxygenated the solution 18,20 . Most recently, Schoenebeck and coworkers demonstrated CP synthesis in air utilizing the high reactivity of a Pd(I) dimer‐based catalyst, which enabled high conversions to be reached before appreciable monomer deactivation via quenching 19 . One limitation of both studies is that control over the molar masses was not achieved, indicating non‐living processes.…”

“…Recognizing this challenge, several recent papers have described a more 'user-friendly' conjugated polymer synthesis, in which the polymerization is performed in air. 18,19 For example, Kanabara and coworkers reported an oxygen-and moisture-tolerant synthesis of thienopyrroledione-based conjugated polymers through a step-growth direct arylation polycondensation, wherein refluxing conditions effectively deoxygenated the solution. 18,20 Most recently, Schoenebeck and coworkers demonstrated CP synthesis in air utilizing the high reactivity of a Pd(I) dimer-based catalyst, which enabled high conversions to be reached before appreciable monomer deactivation via quenching.…”