Advanced supramolecular initiator for nitroxide-mediated polymerizations containing both metal-ion coordination and hydrogen-bonding sites

Abstract

The synthesis of a new difunctional nitroxide initiator combining two orthogonal supramolecular entities is reported; controlled radical polymerization of styrene using this initiator is demonstrated to generate well-defined heterotelechelic polymers in a one-step procedure.

Biomimetische Selbstheilung

“…Andere Arten von Wasserstoffbrückenmotiven wurden von zahlreichen Arbeitsgruppen untersucht und führten zu vielfältigen weichen Materialien mit autonomer Selbstheilung (Abbildung 3). 52…”

Using Metallo‐Supramolecular Block Copolymers for the Synthesis of Higher Order Nanostructured Assemblies

“…Thus, in theory, upon self-assembly into triblock micelles, cross-linking to give nanoparticles and subsequent selective PS core removal, the targeted core hollowed, hydrophobic nanocages incorporating a new PMA internal shell layer could be accessed. An asymmetric SCS Pd(II) pyridine complex linked triblock terpolymer was synthesized with the structure: poly(acrylic acid)-b-poly(methyl acrylate)-[Pd)-PS or PAA 90 -PMA 45 -[Pd)-PS 35 , upon polymerization with functional CRP initiator species. [48] This strategy relies upon the established complexation chemistries of the previous system, but utilizes reversible addition fragmentation chain transfer (RAFT) polymerization to synthesize a covalently linked amphiphilic diblock (PAA 90 -PMA 45 -[Pd) which, when complexed to a second block bearing a pyridine functionality, Figure 11.…”

“…Rapid Commun. 35 (where the notation [Pd) represents the asymmetric linkage between the two homopolymers) via ligand functionalized NMRP initiator techniques. Upon self-assembly into welldefined micelles and cross-linking to give nanoparticles using previously established chemistries, selective bond cleavage of the pyridine-palladium(II) bond was achieved via protonation of the pyridine moiety at low pH.…”

“…[31,32] Recently, researchers have incorporated both non-covalent motifs into polymer architectures to potentially utilize their unique properties, in an attempt to achieve further advanced architectures and applications. [33][34][35] Metal-ligand coordination is a particularly attractive motif since the interaction is highly specific and directional, and its relative binding strength can be readily tuned via metal and ligand selection from a host of well-studied systems. [19,30,36] Moreover, transition metals also offer photophysical, electrochemical, catalytic, and magnetic properties which may further enhance their use and potential application in this field.…”

The power of prediction

“…End‐functional polymers are attractive synthetic targets because the functional moieties can serve as handles for the attachment to other polymers, biomolecules, fluorescent labels, and surfaces. Methods for preparing end‐functional polymers by NMP include postpolymerization modification33–38 or incorporation of functionality onto the initiator39–54 on either the initiating α‐fragment and/or the capping ω‐nitroxide group. The functional initiator method can be an easier route to end‐functional materials because the functionality is carried through the polymerization in a more quantitative manner than with postpolymerization modification.…”