Macromolecular helicity control of poly(phenyl isocyanate)s with a single stimuli-responsive chiral switch

Abstract

The macromolecular helicity of poly(phenyl isocyanate)s can be tuned by a conformational switch of the chiral initiator through a domino effect.

Preparation of poly(thiophene-alt-pyrrole) bearing chiral LC group

“…In other words, distance chirality of terminal optically active group in the mesogen induces main chain chirality. In the previous studies, main chain chirality of polymers was induced by chiral side chain located near position to the main chain, showing molecular functionalities [17][18][19][20][21][22][23]. The polymer prepared in this study is first founding in researches of aromatic LC conjugated polymers that the optically active group in the terminal induces main chain chirality from distance in molecular level.…”

From Sergeants and Soldiers to Chiral Conflict Effects in Helical Polymers by Acting on the Conformational Composition of the Comonomers

“…Dynamic helical polymers, such as poly(phenylacetylene)s (PPAs), are a fascinating family of long chain macromolecules whose helical scaffold (sense and/or elongation) can be modified by the action of different external stimuli [1–10] . This phenomenon has been shown to allow the selective conversion of axially racemic polymers, composed by chiral or achiral monomers, into either of its two helical sense stereoisomers ( M or P ) by the action of solvents (polarity and donor parameters), metal ions, chiral molecules, temperature, or pH [11–20] . On the other hand, if the starting polymer adopts a preferred M or P helix once is prepared, those stimuli can be used to produce structural modifications such as screw sense enhancement or helical inversion [1–20] …”

“…Dynamic helical polymers,such as poly(phenylacetylene)s (PPAs), are afascinating family of long chain macromolecules whose helical scaffold (sense and/or elongation) can be modified by the action of different external stimuli. [1][2][3][4][5][6][7][8][9][10] This phenomenon has been shown to allow the selective conversion of axially racemic polymers,c omposed by chiral or achiral monomers,i nto either of its two helical sense stereoisomers (M or P)b yt he action of solvents (polarity and donor parameters), metal ions,chiral molecules,temperature,o rp H. [11][12][13][14][15][16][17][18][19][20] On the other hand, if the starting polymer adopts ap referred M or P helix once is prepared, those stimuli can be used to produce structural modifications such as screw sense enhancement or helical inversion. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] An alternative way to induce as ingle-handed helical structure in an axially racemic polymer without altering the environmental conditions was described by Green and co-workers and denoted as sergeants and soldiers effect.…”

Chiral information harvesting in helical poly(acetylene) derivatives using oligo(p-phenyleneethynylene)s as spacers

“…1c). [29][30][31] For the rst mechanism-chiral tele-induction-, both exible and rigid spacers have been designed. [20][21][22][23][24][25][26][27][28] In all cases, supramolecular interactions, such as H bonding or p-p stacking, generate organized structures.…”

“…1c). [29][30][31] Herein we will demonstrate another remote chiral induction mechanism based on a different chiral harvesting process. In this case, the chiral center does not produce a conformational change at the achiral spacer, but affects its array within the helical scaffold.…”