Visible-Light-Induced Reversible Complexation Mediated Living Radical Polymerization of Methacrylates with Organic Catalysts

Abstract

Photoinduced reversible complexation mediated polymerization (photo-RCMP) was developed as a new photoinduced living radical polymerization (LRP). It consisted of an alkyl iodide as a dormant species and an amine as a catalyst, using visible light at 350−600 nm. The amine catalysts include such common compounds as tributylamine. Mechanistically, the polymerization is induced by the photolysis of the dormant species and dormant species/catalyst complex, which frequently occurs as the main activation process. The polymer molecular weight and its distribution (M w /M n = 1.1−1.4) were well controlled in the polymerizations of methyl methacrylate and some functional methacrylates up to fairly high conversions in many cases. Perfectly no polymerization took place without photoirradiation, meaning that the system is an ideal photo "on"−"off" switchable system. The polymerization rate was also finely tunable by the external irradiation power. Attractive features of photo-RCMP include the uses of inexpensive compounds and visible light, good polydispersity control, good tolerance to functional groups, and fine response to external photoirradiation.

Macromolecular Architectures Designed by Living Radical Polymerization with Organic Catalysts

“…RTCP and RCMP can be facile and pervasive methodologies for various applications. We previously reported the use of RTCP and RCMP in preparing well-defined linear polymers including homopolymers, random copolymers, and diblock copolymers [16][17][18][19][20][21][22][23][24][25][26][27]. In this paper, we report new examples of diblock copolymers and summarize the diblock copolymers prepared in previous and current works.…”

“…We developed two mechanistically different systems referred to as reversible chain transfer catalyzed polymerization (RTCP) [16][17][18][19][20][21][22][23] and reversible coordination mediated polymerization (RCMP) [24][25][26][27].…”

Living Radical Polymerization via Organic Superbase Catalysis

“…• from R-I with a superbase catalyst [34][35][36][37][38]. We used CP-I (Figure 1) as R-I and TMG and TiBP as catalysts.…”

“…We recently developed new LRP systems using iodine as a capping agent and organic molecules as catalysts. We developed two mechanistically different systems, referred to as reversible chain transfer-catalyzed polymerization (RTCP) [25][26][27][28][29][30][31] and reversible coordination-mediated polymerization (RCMP) [31][32][33][34][35]. These polymerizations are metal-free systems.…”

“…In this work, we focus on the latter system (RCMP). We previously employed amines, such as triethylamine (TEA) [32,34] and organic salts, such as tetrabutylammonium iodide (BNI) [35], as RCMP catalysts. RCMP involves reversible coordination of the catalyst to Polymer-I to generate Polymer We are pursuing more reactive catalysts to widen the scope of RCMP.…”