Self‐Discriminating Termination of Chiral Supramolecular Polymerization: Tuning the Length of Nanofibers

Abstract

Directing the supramolecular polymerization towards a preferred type of organization is extremely important in the design of functional soft materials. Proposed herein is a simple methodology to tune the length and optical chirality of supramolecular polymers formed from a chiral bichromophoric binaphthalene by the control of enantiomeric excess (ee). The enantiopure compound gave thin fibers longer than a few microns, while the racemic mixture favored the formation of nanoparticles. The thermodynamic study unveils that the heterochiral assembly gets preference over the homochiral assembly. The stronger heterochiral binding over homochiral one terminated the elongation of fibrous assembly, thus leading to a control over the length of fibers in the nonracemic mixtures. The supramolecular polymerization driven by π-π interactions highlights the effect of the geometry of a twisted π-core on this self-sorting assembly.

Strong and Reversible Circularly Polarized Luminescence Emission of a Chiral 1,8‐Naphthalimide Fluorophore Induced by Excimer Emission and Orderly Aggregation

“…Kawai and coworkers have carried out some preeminent work on CPL materials . They designed and synthesized a novel bichromophoric perylene bisimide incorporating a chiral binanphthane diamine moiety that showed an enhanced CPL response signal due to the formation of nanostructures through the effective integration of individual bichromophoric molecules . Recently, our group synthesized two chiral 1,2‐DACH‐based polymers with strong mirror‐image Cotton effects and red‐colored CPL emission due to the effective chirality transfer from the 1,2‐diaminocyclohexane Schiff base to a BODIPY chromophore via the conjugated polymer chain backbone…”

Enhanced Circularly Polarized Luminescence in Emissive Charge‐Transfer Complexes

“…Then, the dimer and TCNB sandwiched one another with the CT interaction to form mixed-stack packing along the c axis (Supporting Information, Figure S24), which leads to the long-range ordered fibers.F urthermore,t he assembled CT fibers entangled with each to generate networks and supramolecular structures.I t should be emphasized that CT interaction in solution is too weak to form gel. [17] However,further discussion of fundamental analysis about CPL was seldom involved. TheC T interaction could be enhanced by the ultrasound (Figure 5d).…”

Circularly Polarized Luminescence of Chiral Perylene Diimide Based Enantiomers Triggered by Supramolecular Self‐Assembly

“…The structures of the obtained chiral d / l ‐PDI were found to be different to those of previously reported perylene diimide based chiral molecules with CPL properties even though a similar perylene diimide structure was employed as the self‐assembling group. In this work we compared the structures of our d / l ‐PDI with those of Kawai and Haino and their co‐workers (Scheme ) . Kawai and co‐workers chose chiral binaphthyldiamine or (dicyclohexylmethyl)amine as PDI substituents, which gave a PDI with a more rigid framework than our chiral molecule .…”

“…Perylene diimide (PDI) based derivatives, as a class of excellent chromophores, have been designed and successfully used as CPL emission materials . Recently, Kawai and co‐workers reported a chiral binaphthalene compound tethering two PDI moieties, the CPL properties of which could be controlled by the lengths of the fibrous structures through self‐assembly . Kawai and co‐workers also designed a novel chiral bichromophoric PDI derivative that could produce an enhanced CPL signal induced by the formation of chiral nanostructures by the effective integration of individual bichromophoric molecules …”