海滨稚子

The synergy of aromatic gain and hydrogen bonding in a supramolecular polymer is explored. Partially aromatic bis(squaramide) bolaamphiphiles were designed to self-assemble through a combination of hydrophobic, hydrogen-bonding, and aromatic effects into stiff, high-aspect-ratio fibers. UV and IR spectroscopy show electron delocalization and geometric changes within the squaramide ring indicative of strong hydrogen bonding and aromatic gain of the monomer units. The aromatic contribution to the interaction energy was further supported computationally by nucleus-independent chemical shift (NICS) and harmonic oscillator model of aromaticity (HOMA) indices, demonstrating greater aromatic character upon polymerization: at least 30 % in a pentamer. The aromatic gain–hydrogen bonding synergy results in a significant increase in thermodynamic stability and a striking difference in aggregate morphology of the bis(squaramide) bolamphiphile compared to isosteres that cannot engage in this effect.

Getting in tune: The synergy of aromatic gain and hydrogen bonding is observed in an aqueous supramolecular polymer consisting of squaramide-based bolaamphiphiles. The aromatic gain effect accounts for more than 30 % of the total interaction energy among squaramide pentamers. The interplay between polymer self-assembly and reciprocal hydrogen-bonding–aromaticity interactions is examined.

While great progress has been achieved in the synthesis of ordered mesoporous carbons in the past decade, it still remains a challenge to prepare highly graphitic frameworks with ordered mesoporosity and high surface area. Reported herein is a simple synthetic methodology, based on the conversion of self-assembled superlattices of Fe₃O₄ nanocrystals, to fabricate highly ordered mesoporous graphene frameworks (MGFs) with ultrathin pore walls consisting of three to six stacking graphene layers. The MGFs possess face-centered-cubic symmetry with interconnected mesoporosity, tunable pore width, and high surface area. Because of their unique architectures and superior structural durability, the MGFs exhibit excellent cycling stability and rate performance when used as anode materials for lithium-ion batteries, thus retaining a specific capacity of 520 mAh g⁻¹ at a current density of 300 mA g⁻¹ after 400 cycles.

Framed: The title frameworks were fabricated from self-assembled Fe₃O₄ nanocrystal superlattices. Because of their unique architectures and superior structure durability, the mesoporous graphene frameworks exhibit excellent electrochemical performance when used as anode materials for lithium-ion batteries.