Macro‐scale helices co‐assembled from chirality‐transferring temperature‐responsive carbohydrate‐based bolaamphiphiles and 1,4‐benzenediboronic acid

Using small molecules to assemble well-controlled macro-sized helices is still a great challenge and highly desired for advanced materials. Here, we present the first example of the macro-scale helices co-assembled from temperature-responsive carbohydrate-based bolaamphiphiles (CHO-Bolas) and 1,4-benzenediboronic acid (BDBA). The CHO-Bolas contained hydrophilic glucose or mannose moieties and hydrophobic coumarin dimer. They showed temperature-responsive reversible micelle-to-vesicle transition (MVT) in aqueous solutions. After the binding of carbohydrate moieties with boronic acids of BDBA in their alkaline solutions, right-handed helices were formed via the temperature-driven chirality transfer of D-glucose or D-mannose from molecular to supramolecular level. The helices with the length of hundreds of microns had helical pitches of 5.4-6.3 μm and lamellae thickness of 0.2-0.3 μm. These helices were co-assembled by unreacted BDBA, boronate esters (B-O-C bonds) between CHO-Bolas and BDBA, as well as boroxine anhydrides (B-O-B bonds) of self-condensed BDBA. After heating treatment at 300 °C in nitrogen gas, helices displayed excellent morphological stability. Moreover, they emitted bright blue luminescence caused by strong self-condensation of BDBA and decomposition of coumarin dimers.