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Abstract The fabrication of truly hierarchically folded single‐chain polymeric nanoparticles with primary, secondary, and defined 3D architecture is still an unfulfilled goal. In this contribution, a polymer is reported that folds into a well‐defined 3D structure from a synthetic sheet‐helix block copolymer. The sheet‐like poly(p‐phenylene vinylene) (PPV) block is synthesized via the ring‐opening metathesis polymerization of a thymine‐bearing dialkoxy‐substituted [2.2]paracyclophane‐1,9‐diene. The PPV block is terminated with a Pd complex using a Pd‐containing chain‐terminating agent. The terminal Pd complex catalyzes the polymerization of isocyanide monomers with side‐chains containing either a chiral menthol or an achiral diaminopyridine resulting in the formation of a helical poly(isocyanide) (PIC) random copolymer. The PIC side‐chains are capable of engaging in complementary hydrogen‐bonding with thymine units along the PPV block resulting in the folding of the two secondary structural domains into a well‐defined 3D structure. The folding and unfolding of the polymer in both chloroform and THF are monitored using dynamic light scattering and NMR spectroscopy. This work is the first example of a hierarchically folded synthetic polymer featuring a defined 3D structure achieved by using two different polymer backbones with two distinct secondary structures.
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Intramolecular Folding of Coil‐Helix Block Copolymers Induced by Quadrupole Interactions
Abstract True tertiary architectures with defined local secondary structures are rare in synthetic systems. Adapting well‐developed synthetic building blocks and controlling their folding through diverse interactions can be a general approach toward this goal. In this contribution, the synthesis of 3D hierarchical assemblies with distinct secondary domains formed through the intramolecular folding of a block copolymer containing a coil‐like poly(styrene) (PS) block with a helical poly(isocyanide) block induced by phenyl‐pentafluorophenyl quadrupole interactions is reported. The PS block is prepared via atom‐transfer radical polymerization and end functionalized with a nickel complex that serves as a macroinitiator for the polymerization of chiral isocyanides bearing pentafluorophenyl pendants. The folding behavior of the coil‐helix block copolymers is investigated by dynamic light scattering, NMR spectroscopy, wide‐angle X‐ray scattering, and differential scanning calorimetry.
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- Award ID(s):
- 1902917
- PAR ID:
- 10449475
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Macromolecular Rapid Communications
- Volume:
- 42
- Issue:
- 19
- ISSN:
- 1022-1336
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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