We report supramolecular AB diblock copolymers comprised of well-defined telechelic building blocks. Helical motifs, formed via reversible addition-fragmentation chain-transfer (RAFT) or anionic polymerization, are assembled with coil-forming and sheet-featuring blocks obtained via atom-transfer radical polymerization (ATRP) or ring-opening metathesis polymerization (ROMP). Interpolymer hydrogen bonding or metal-coordination achieves dynamic diblock architectures featuring hybrid topologies of coils, helices, and/or π-stacked sheets that, on a basic level, mimic protein structural motifs in fully synthetic systems. The intrinsic properties of each block (e.g., circular dichroism and fluorescence) remain unaffected in the wake of self-assembly. This strategy to develop complex synthetic polymer scaffolds from functional building blocks is significant in a field striving to produce architectures reminiscent of biosynthesis, yet fully synthetic in nature. This is the first plug-and-play approach to fabricate hybrid π-sheet/helix, π-sheet/coil, and helix/coil architectures via directional self-assembly.

Two chemically distinct monotelechelic helical polymers were synthesized using anionic and reversible addition−fragmentation chain-transfer (RAFT) polymerizations. A chiral poly(isocyanide) block was obtained using a palladium−ethynyl complex modified with the N 1 ,N 3 -bis(6-butyramidopyridin-2yl)-5-hydroxyisophthalamide (Hamilton wedge) moiety as a catalyst employing anionic polymerization. A complementary barbiturate-functionalized chain-transfer agent was used to polymerize chiral N-(1-(naphthalen-2-yl)ethyl)methacrylamides by RAFT polymerization. The assembly into helix−helix supramolecular block copolymers in chloroform via hydrogen bonding was analyzed by 1 H NMR spectroscopy, resulting in an average measured association constant of (9.5 ± 0.5) × 10 3 M −1 . After block copolymer formation, the secondary structures of both helical polymers were maintained within the block copolymer, as evidenced by circular dichroism and infrared spectroscopies. Films were prepared from a 1:1 mixture of polymers in solution and were analyzed by WAXS and DSC to evaluate organization in the solid state. While diblock formation in the solution phase is readily obtainable, there was little evidence supporting a self-assembly assisted microstructure in the solid state. This work demonstrates a synthetic methodology for obtaining two telechelic helical polymers capable of supramolecular assembly in solution toward the goals of developing multifunctional polymeric ensembles.

Coil-helix and sheet-helix block copolymers are synthesized by combining the ring-opening metathesis polymerization (ROMP) of norbornene or paracyclophanediene with the anionic polymerization of phenyl isocyanide. Key to the design is the use of an l-ethynyl palladium (II) functionalized chaintransfer agent (CTA) that can be exploited in a stepwise manner for the termination of ROMP and the initiation of the anionic polymerization. Both the coil-and sheet-macroinitiators, and the ensuing covalent block copolymers, are analyzed using 1 H NMR spectroscopy and gel-permeation chromatography. In all cases, the Pd-end group is maintained and all polymers demonstrate a monomodal distribution with dispersities ( -D) of 1.1-1.4. The resulting helix-coil and helix-sheet block copolymers formed by the macroinitiation route still demonstrate their intrinsic properties (fluorescence, preferential helixsense).

This contribution presents the synthesis of helical alkyne‐terminated polymers using a functionalized Nickel complex to initiate the polymerization of menthylphenyl isocyanides. The resulting polymers display low dispersities and controlled molecular weights. Copper‐catalyzed azide/alkyne cycloadditions (CuAAC) are performed to attach various azide‐containing compounds to the polymer termini. After azido‐phosphonate moiety attachment the polymer displays a signal at 25.4 ppm in the 31P NMR spectrum demonstrating successful end‐group functionalization. End‐group functionalization of a fluorescent dye allows to determine the functionalization yield as 89% (±8). Successful ligation of an azide‐functionalized peptide sequence (MKLA = 1547 g/mol) increases the Mn from 5100 for the parent polymer to 6700 for the bioconjugate as visualized by GPC chromatography. Analysis by CD spectroscopy confirms that the helical conformation of the poly(isocyanide) block in the peptide–polymer conjugate is maintained after postpolymerization modification. These results demonstrate an easy, generalizable, and versatile strategy toward mono‐telechelic helical polymers. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2766–2773

We report supramolecular AB diblockc opolymers comprised of well-defined telechelic building blocks.H elical motifs,f ormed via reversible addition-fragmentation chaintransfer (RAFT) or anionic polymerization, are assembled with coil-forming and sheet-featuring blocks obtained via atom-transfer radical polymerization (ATRP) or ring-opening metathesis polymerization (ROMP). Interpolymer hydrogen bonding or metal-coordination achieves dynamic diblock architectures featuring hybrid topologies of coils,h elices, and/or p-stacked sheets that, on ab asic level, mimic protein structural motifs in fully synthetic systems.T he intrinsic properties of eachb lock( e.g.,c ircular dichroism and fluorescence) remain unaffected in the wake of self-assembly.T his strategy to develop complex synthetic polymer scaffolds from functional building blocks is significant in af ield striving to produce architectures reminiscent of biosynthesis,y et fully synthetic in nature.This is the first plug-and-playapproach to fabricate hybrid p-sheet/helix, p-sheet/coil, and helix/coil architectures via directional self-assembly.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under http://dx.