Unusual enhancement of degradation rate induced by polymer chain elongation in quaternized polyethyleneimine derivatives
Rafał Kopiasz , Michał Szczepańczyk , Dominik Jańczewski
AbstractOur study on antimicrobial ionenes revealed an unusual chemical property of quaternized linear polyethyleneimine (L-PEI) derivatives. The polymer backbone reactivity toward hydroxide strongly increases with the added number of repeating units. Methylated L-PEI and its oligomer containing four mers underwent rapid elimination in such mild alkaline conditions as 0.1 mol/L Na2CO3 solution at 25 °C, whereas two mer oligomer remained stable. The rigid oligomeric analog containing alkylated 1,4-diazabicyclo[2.2.2]octane subunits were even more reactive. The effect can be explained by the increased polarization of CeH bond that follows the chain elongation. Such hypothesis is well supported by a good correlation of reaction rates with 1 H NMR chemical shifts of eliminated hydrogens, what inspired discussion on possibly involved E1cB and E2 mechanisms. The observed correlation can be used to predict stability of polycations, which is an important issue in both biomedical and energy storage fields.
|Journal series||Reactive & Functional Polymers, ISSN 1381-5148|
|Publication size in sheets||0.5|
|Keywords in English||Polycation, Ionene, Polyethyleneimine stability, PEI, Hofmann elimination|
|ASJC Classification||; ; ; ; ;|
|Score||= 70.0, 26-06-2020, ArticleFromJournal|
|Publication indicators||= 1; = 2; : 2017 = 0.993; : 2018 = 3.074 (2) - 2018=3.076 (5)|
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