The M-helicity of asymmetric N-triphenylamine-based supramolecular polymers was inverted to the P-helicity during heating.

We demonstrate the different origins of helical directions in polymeric gels derived from a hydrazone reaction in the absence and presence of Ni. The right-handed helicity of polymeric gels without Ni originates from the enantiomeric d-form alanine moiety embedded in the building block. However, the right-handed helicity is inverted to a left-handed helicity upon the addition of Ni, indicating that added Ni greatly affects the conformation of the polymeric gel by overcoming the influence of the enantiomer embedded in the building block on the helicity at the supramolecular level. More interestingly, the ratio of the right-toleft-handed helical fibers varies with the concentration of Ni, which converts from 100% right-handed helical fiber to 90% left-handed helical fiber. In the presence of Ni, both right- and left-handed helical fibers coexist at the supramolecular level. Some fibers also exhibit both right- and left-handed helicities in a single fiber.

This paper describes the peculiar co-assembly supramolecular polymerization behavior of triphenylamine trisamide derivatives with d-alanine (T-ala) or glycine (T-gly) moieties. Concentration and temperature-dependent circular dichroism (CD) spectroscopy revealed that the heating curves of co-assemblies obtained at various molar ratios of T-ala to T-gly exhibited two distinct transition temperatures. The first transition was due to the transformation from coiled helical bundles to single helical fibers without handedness. The second was due to a change from typical elongation to nucleation. These phenomena were confirmed by solvent-dependent decoiling of coiled helical structures and concentration-dependent morphological analysis. The two transitioning temperatures were dependent on the concentration of T-ala in the co-assemblies, suggesting that T-ala concentration plays an important role in the formation of coiled helical bundles. Our study demonstrated the first observation of two distinct transition temperatures in supramolecular polymers.

A mixture of the building blocks 1A and 2G, featuring d‐alanine moieties and glycine‐functionalized calix[4]arene moieties, respectively, formed a co‐assembled hydrogel. In particular, the remarkable enhancement of helical intensity of co‐assembled gel was controlled by achiral calix[4]arene 2G, which was attributed to the bridging effect between 1A and 2G, similar to a helical structure. Furthermore, the improvement of the mechanical strength (G′ and G′′ values) of the co‐assembled hydrogel prepared with 1.0 equivalent of 2G were around 7000 % and 4400 % stronger, respectively, compared to the gel prepared from the 0.25 equivalents of 2G. The improved mechanical strength was attributed to the formation of a network structure with a H‐bonding interaction between 1A and 2G. The results indicate that the enhanced helical and mechanical strength of the co‐assembled gel could be controlled by achiral component 2G.

A mixture of the bipyridine, phenyl and/or cyclohexanediamine-based building blocks 1, 2, and/or 3, having hydrazide, aldehyde or amine moieties, respectively, formed DMSO polymer gels by the hydrazone reaction under acidic conditions.