Supramolecular Diblock Copolymers Featuring Well‐defined Telechelic Building Blocks

Abstract

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.

Synthesis and Light‐Mediated Structural Disruption of an Azobenzene‐Containing Helical Poly(isocyanide)

“…GPC yielded dispersities in line with our previously reported poly(isocyanide) systems (Ð = 1.54, M n = 8500 g/mol). [12][13][14][15]34] 1 H NMR spectroscopy also confirmed polymer formation through the broadening of backbone peaks when going from monomer to polymer ( Figure S23). [35] Due to a limited signal, we were not able to verify the end-group functionalization with the alkyne group.…”

“…First discovered in the 1970s, helical poly(isocyanide)s have since been used in the fabrication of a number of materials including temperature-responsive hydrogels and supramolecular block copolymers that act as analogs to different tertiary structure motifs. [7][8][9][10][11][12][13][14][15] Poly(isocyanide)s are classified as 'static' helical systems due to their high inversion barrier when the side groups are sufficiently bulky. [3,9] As a result of this high inversion barrier, poly(isocyanide)s retain their helical handedness, left-or right-handed, at room temperature.…”

“…The dispersity obtained through GPC (Ð = 1.32, M n = 5500 g/mol) is in line with dispersity values of poly(isocyanide)s in the literature. [12][13][14][15]34] CD spectroscopy was performed to study the handedness of the helix and to see if the conformation could be affected using light as stimulus (Figure 3). Alanine-based poly(isocyanide)s featuring an amide bond in their side-chains, as is the case in our system (Figure 1), are well-studied and are known to form stable helical structures due to both side-chain bulk and the hydrogen bonding network along the side-chains at repeat units n and n + 4.…”

“…coil and sheet). [12][13][14][15]39,40] To synthesize alkyne-containing helix 7, we first synthesized an alkyne-functionalized nickel(II) initiator previously reported by our group. [34] The initiator and monomer were combined in DCM and reacted for 12 hours at room temperature.…”

Polymer Containing Multiple Secondary Structures—A Competition between Helical Induction and C‐T Complexation

“…[36] In addition, the same research group has developed a few other block copolymers that self-assembled into a complex folded structure. [37][38][39][40][41] This paper describes the design and synthesis of two triblock copolymers (A-B-A) that differ in the chain length of the "A" block. The block copolymers (A-B-A) feature block "A" at both ends displaying stable helical conformations while the secondary structure of the middle block (B) is tunable.…”