Morishita Daiki, Itoh Yoshimitsu, Furukawa Ko, Arai Noriyoshi, Zhang Xu-Jie, Aida Takuzo
Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan
Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST) 4-1-8 Honcho Kawaguchi Saitama 332-0012 Japan.
Chem Sci. 2024 Feb 5;15(11):4068-4074. doi: 10.1039/d3sc06341k. eCollection 2024 Mar 13.
In the case of covalent polymers, immiscible polymers can be integrated by covalently linking them together, but such a strategy is not possible in supramolecular polymers. Here we report the supramolecular copolymerization of two porphyrin-based monomers, P and P with side chains bearing cyanobiphenyl (CB) groups at the ends of hydrophobic alkyl or hydrophilic tetraethylene glycol chains, respectively. These monomers undergo self-sorting supramolecular polymerization in highly diluted solutions ([monomer] = 3.4 × 10 mol% (2.0 × 10 mol L)) in nonpolar media due to the incompatibility of the side chains. Surprisingly, these monomers undergo supramolecular copolymerization under high concentration conditions ([monomer] = 7.7 mol%) in the medium of 4-cyano-4'-pentyloxybiphenyl (5OCB) to form a columnar liquid crystalline phase under thermodynamic conditions, where the individual columns are composed of supramolecular block copolymers. The combination of CB ends of both monomers and the 5OCB medium is essential for the two monomers to form an integrated structure in a condensed system without phase separation.
对于共价聚合物而言，不相容的聚合物可通过共价连接整合在一起，但这种策略不适用于超分子聚合物。在此，我们报道了两种基于卟啉的单体P和P*的超分子共聚反应，其侧链分别在疏水烷基或亲水四甘醇链末端带有氰基联苯（CB）基团。由于侧链不相容，这些单体在非极性介质中的高稀释溶液（[单体]=3.4×10⁻⁵mol%（2.0×10⁻⁵mol/L））中发生自分类超分子聚合。令人惊讶的是，这些单体在4-氰基-4'-戊氧基联苯（5OCB）介质中的高浓度条件（[单体]=7.7mol%）下发生超分子共聚反应，在热力学条件下形成柱状液晶相，其中各个柱体由超分子嵌段共聚物组成。两种单体的CB末端与5OCB介质的结合对于两种单体在凝聚体系中形成无相分离的整合结构至关重要。
