We introduce the formation of a dual responsive supramolecular star polymer system, displaying gated selfassembly behavior. The redox-and thermoresponsive star polymers are based on a 6-fold β-CD functionalized core molecule and RAFT-derived ferrocene end functionalized poly(N,N-dimethylacrylamide) (PDMA) and poly(N,N-diethylacrylamide) (PDEA) linear polymers. Complex formation is analyzed via various methods including dynamic light scattering (DLS). Chemical redox triggers, namely NaOCl and ascorbic acid, as well as electrochemical triggers can be utilized to shift the star polymers to the unbound state via CD/ferrocene complex dissociation. Moreover, heating above the lower critical solution temperature (approximately 34 °C) allows for a change from the coil to the globular state of the star polymers in the case of PDEA arms. For PDMA arms, heating to 70 °C allows shifting of the system to the unbound state. The response of the supramolecular star polymers is carefully studied via various methods including cyclic voltammetry (CV), DLS, and turbidimetry. Overall, the supramolecular star polymers can be transformed into predefined states via individually addressable temperature and/or redox stimuli, presenting a novel dual gated self-assembling supramolecular star polymer system in aqueous solution.
The combination of the Passerini reaction and olefin cross-metathesis is shown to be a very useful approach for the divergent synthesis of dendrimers. Castor oil-derived platform chemicals, such as 10-undecenoic acid and 10-undecenal, are reacted in a Passerini reaction with an unsaturated isocyanide to obtain a core unit having three terminal double bonds. Subsequent olefin cross-metathesis with tert-butyl acrylate, followed by hydrogenation of the double bonds and hydrolysis of the tert-butyl ester, leads to an active core unit bearing three carboxylic acid groups as reactive sites. Iterative steps of the Passerini reaction with 10-undecenal and 10-isocyanodec-1-ene for branching, and olefin cross-metathesis with tert-butyl acrylate, followed by hydrogenation and hydrolysis allow the synthesis of a third-generation dendrimer. All steps of the synthesis are carefully characterized by NMR, GPC, MS, and IR.
Front Cover: Renewable castor‐oil‐based dendrimers are synthesized combining the efficient Passerini three component reaction with olefin cross‐metathesis. After preparing the core molecule, iterative steps of the Pass erinireaction with 10‐undecenal and 10‐isocyanodec‐1‐ene for branching, and olefin cross‐metathesis with tert‐butyl acrylate, followed by hydrogenation and hydrolysis allow the synthesis of a third‐generation dendrimer. Further details can be found in the article by O. Kreye, D. Kugele, L. Faust, and M. A. R. Meier* on page 317.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.