Visible Light Induced Solubility Modulation of Polynorbornene Bearing Bridged 1, 2‐Diketones. Issue 5 (14th April 2021)

• Record Type: Journal Article
• Authors: Kim, Kyungrae; Seo, Donghwa; Kim, Dowan; Lim, Jeewoo
• Is Part Of: Asian journal of organic chemistry. Volume 10:Issue 5(2021)
• Page Start: 1081
• Page End: 1084
• Publication Date: 2021-04-14
• Subjects: photochemistry -- polymer solubility modulation -- 1, 2-diketones -- ROMP -- polymer nanoparticles; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; 547.005
• DOI: 10.1002/ajoc.202100099
• Languages: English
• ISSNs: 2193-5807

Abstract

Abstract: We herein report the synthesis and photoinduced solubility modulation of a poly(norbornene) bearing bridged 1, 2‐diketone units in the repeating unit. Selective irradiation of the n to π* absorption band of the monomer using a blue LED light source emitting at 455 nm lead to a rapid and quantitative decarbonylation at the diketone bridge, yielding the corresponding anthracene derivative. Identical photoinduced decarbonylation was observed in the polymer obtained from the ring‐opening metathesis polymerization (ROMP) of the photoreactive monomer. The polymer displayed photoinduced solubility change wherein irradiation of the polymer solution in various solvent systems with a blue LED light source led to the precipitation of the polymer, producing polymer nanoparticles. The solubility change is attributed to the change in the free volume of the polymer and constitutes a method of photoinduced solubility modulation in which only gaseous byproducts are generated from the photocleavage reaction. Abstract : Preparation of well‐defined polymer nanoparticles using visible light is reported . This non‐invasive method of polymer solubility modulation involves a rapid and quantitative photoinduced decarbonylation 1, 2‐diketones incorporated into the polymer structure. The photoinduced polymer precipitation takes place within a minute in an appropriate solvent system, and may be monitored by the rapid drop in the transmittance of the polymer solution.