Remote Control of One‐Handed Helicity in Polyacetylenes through Flexible Spacers in Water: Impact of the Spacer Length

Abstract

We report the unprecedented sergeants and soldiers (S&S)‐type remote control of one‐handed helicity in copolymers of chiral/achiral biphenylylacetylenes bearing amphiphilic oligo(ethylene glycol) (OEG) side chains. A small amount of chiral binaphthyl residues (≤10 mol %) introduced at the terminal of the achiral OEG spacers as many as 80 bonds away from the polymer backbones induced a complete one‐handed helix in water through preferential intramolecular encapsulation of the binaphthyl groups within a cavity of the copolymers. A fully one‐handed helix can be induced virtually independent of the OEG spacer length and concentrations. At a specific spacer length, however, its helix‐sense was inverted. The copolymers also form an excess one‐handed helix in organic solvents in an OEG spacer‐length dependent manner, yet far from the polymer backbones. We show the superiority of the present covalent‐bond driven S&S‐type remote helicity control over the corresponding noncovalent helicity induction approach.

Chiral Polyacetylene with Thermally Activated Delayed Fluorescence Feature for High-Performance Circularly Polarized Light Detection

“…Moreover, the copolymerization of chiral monomers can result in chiral amplification with a helical architecture due to the "sergeants and soldiers" effect. 10 As a representative example, Ma and co-workers 11 isobutylphenyl-N-propanamide derivative with the phosphorescence chromophore of 4-bromo-1,8-naphthalimide derivative, which displays high absorption and luminescent dissymmetry factors up to 0.029 and 0.019, respectively. Regarding effective exciton generation and utilization in the photodetectors, the substituted chiral helical PAs require chirality-sensitive optical absorption with high exciton harvesting efficiency.…”

“…The prerequisite for realizing a high-performance CPL photodetector is the development of intrinsically chiral materials with superior optoelectronic properties. Substituted polyacetylenes (PAs), a type of prototypical conjugated polymers, have attracted considerable attention in chiroelectronics because of their tunable structural asymmetry, excellent semiconducting properties, and versatile modification. − The PA backbone could be regarded as an ideal platform for integrating optically active chiral side chains, enabling direct CPL identification. Moreover, the copolymerization of chiral monomers can result in chiral amplification with a helical architecture due to the “sergeants and soldiers” effect .…”

“…Substituted polyacetylenes (PAs), a type of prototypical conjugated polymers, have attracted considerable attention in chiroelectronics because of their tunable structural asymmetry, excellent semiconducting properties, and versatile modification. − The PA backbone could be regarded as an ideal platform for integrating optically active chiral side chains, enabling direct CPL identification. Moreover, the copolymerization of chiral monomers can result in chiral amplification with a helical architecture due to the “sergeants and soldiers” effect . As a representative example, Ma and co-workers constructed the helical polyacetylene films by copolymerizing the chiral 4-isobutylphenyl-N-propanamide derivative with the phosphorescence chromophore of 4-bromo-1,8-naphthalimide derivative, which displays high absorption and luminescent dissymmetry factors up to 0.029 and 0.019, respectively.…”

P/M Macromolecular Switch Based on Conformational Control Exerted by an Achiral Side Chain within an Axially Chiral Locked Pendant

“…Dynamic helical polymers are macromolecular switches − where the P/M screw sense control is achieved by resorting to different helix induction mechanisms that arise from the conformational manipulation of the pendant of a monomer repeating unit because of interactions with different stimuli. Thus, information from the chiral center to the main chain of the polymer can be transmitted directly, across space, through helical induction effects such as tele-induction, − chiral overpass, , or substituent overpass, or indirectly, in a two-step process, where information from a chiral group placed at a remote position on the pendant is first transmitted to an achiral spacer and then harvested by the polyene backbone (chiral harvesting). − In copolymers, Zentel et al designed an isocyanate copolymer that shows reversible helix-inversion induced by isomerization of an azobenzene group. , …”

Synthesis of Stereocontrolled Degradable Polymer by Living Cascade Enyne Metathesis Polymerization

“…[1][2][3][4][5][6] Highly ordered chiral polymers can be expressed as helical polymers, and most artificial helical polymers are prepared using asymmetric polymerizations, which provide one-handed helicity, from achiral monomers and chiral catalysts or initiators to form a stereocontrolled covalent linkage. [7][8][9][10][11][12][13][14][15][16][17] Preparation of chiral monomer is not easy. Previous work mostly relied on the chiral pool approach, which generally provides one enantiomer.…”