Controlling the self‐assembly morphology of π‐conjugated block copolymer is of great interesting. Herein, amphiphilic poly(3‐hexylthiophene)‐block‐poly(phenyl isocyanide)s (P3HT‐b‐PPI) copolymers composed of π‐conjugated P3HT and optically active helical PPI segments were readily prepared. Taking advantage of the crystallizable nature of P3HT and the chirality of the helical PPI segment, crystallization‐driven asymmetric self‐assembly (CDASA) of the block copolymers lead to the formation of single‐handed helical nanofibers with controlled length, narrow dispersity, and well‐defined helicity. During the self‐assembly process, the chirality of helical PPI was transferred to the supramolecular assemblies, giving the helical assemblies large optical activity. The single‐handed helical assemblies of the block copolymers exhibited interesting white‐light emission and circularly polarized luminescence (CPL). The handedness and dissymmetric factor of the induced CPL can be finely tuned through the variation on the helicity and length of the helical nanofibers.
Self-sorting playsacrucial role in living systems such as the selective assembly of DNAa nd specific folding of proteins.However,the self-sorting of artificial helical polymers such as biomacromolecules has rarely been achieved.I nt his work, single-handed helical poly(phenyl isocyanide)s bearing pyrene (Py) and naphthalene (Np) probes were prepared, which exhibited interesting self-sorting properties driven by both helicity and molecular weight (M n)insolution, solid state, gel, and on the gel surface as well. The polymers with the same helix sense and similar M n can self-sort and assemble into welldefined two-dimensional smectic architectures and form stable gels in organic solvents.I nc ontrast, mixed polymers with opposite handedness or different M n were repulsive to each other and did not aggregate.M oreover,t he gels of helical polymers with the same handedness and similar M n can recognizet hemselves and adhere together to form ag el.
Macroporous polymer frameworks with a tunable pore size were readily prepared using 4-arm rod-like polymers as building blocks. They showed excellent iodine capture performance with very high efficiency (1 minute) and high capacity (574%).
Inspired by highly efficient and enantioselective reactions catalyzed by biomacromolecules, developing artificial helical polymer-based catalysts for enantioselective reactions is an interesting work. In this work, a series of one-handed helical polyisocyanides bearing aryl iodine pendants were readily produced via asymmetric polymerization of achiral isocyanides using chiral Pd(II)-catalysts. Despite the inexistence of any stereogenic centers, these polymers showed large optical activity owing to the one-handed helicity. Remarkably, these polymers could catalyze asymmetric dearomatization spirocyclization of 1-hydroxy-N-aryl-2-naphthamide derivatives and gave chiral spirooxindole products with high enantioselectivity. The enantioselectivity was contributed by the helicity of the polyisocyanide backbone; helical polyisocyanides in opposite helicity produced the enantiomeric antipode products with comparable yields and similar high enantioselectivity. Thanks to the high molecular weight, the helical polymer catalysts could be recycled 10 times with maintained activity and stereoselectivity.
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