Inhibitory regulation mechanism of naphthoquinone and its derivatives in radical polymerization. (25th February 2019)

• Record Type: Journal Article
• Authors: Ichihara, Kenta; Kawamura, Izuru; Sakakibara, Kazuhisa; Ikejiri, Yujirou; Himori, Shunichi
• Is Part Of: Journal of physical organic chemistry. Volume 32:Number 6(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-02-25
• Subjects: DFT B3LYP/6‐311+G** -- inhibitory regulation mechanism -- isolated reaction products -- methyl 2‐methylpropionate radical -- naphthoquinone; Chemistry, Physical organic -- Periodicals; 547.1
• DOI: 10.1002/poc.3941
• Languages: English
• ISSNs: 0894-3230

Abstract

Abstract: The inhibitory regulation mechanism towards the methyl 2‐methylpropionate radical (a model of the poly(methyl methacrylate) [MMA] propagation radical) by naphthoquinone derivatives in radical polymerization in an aerobic or anaerobic atmosphere has been studied experimentally by liquid chromatography, mass spectrometry, and nuclear magnetic resonance (NMR) measurements of the isolated reaction products, which were purified by preparative thin‐layer chromatography. In addition, we have carried out a theoretical analysis (DFT B3LYP/6‐311+G**) of the frontier orbital interactions and reaction Gibbs free energies (Δ G ) for the formation of the relevant reaction products and intermediates and activation free energies (Δ G # ) and frontier electron densities (fA (R) ) of the radical reactions. Consequently, the reaction mechanism where quinone products are formed by the attack of propagation radicals at the C2 carbon next to the carbonyl group in naphthoquinone was rationalized. Abstract : The inhibitory regulation mechanism towards the methyl 2‐methylpropionate radical (a model of the poly(methyl methacrylate) [MMA] propagation radical) by naphthoquinone derivatives in radical polymerization in an aerobic or anaerobic atmosphere has been studied experimentally by liquid chromatography, mass spectrometry, and nuclear magnetic resonance (NMR) measurements of the isolated reaction products in conjunction with DFT B3LYP/6‐311+G** theoretical consideration.