Catti L, Aoyama S, Yoshizawa M. Facile access to pyridinium-based bent aromatic amphiphiles: nonionic surface modification of nanocarbons in water.
Beilstein J Org Chem 2024;
20:32-40. [PMID:
38230357 PMCID:
PMC10790643 DOI:
10.3762/bjoc.20.5]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/04/2023] [Indexed: 01/18/2024] Open
Abstract
Efficient water-solubilization of nanocarbons is desirable for both their biological and material applications, but so far has mainly relied on covalent modifications or amphiphiles featuring ionic side-chains. Here, we report a facile 2-4-step synthesis of pyridinium-based, bent aromatic amphiphiles with modular nonionic side-chains (i.e., CH3 and CH2CH2(OCH2CH2)2-Y (Y = OCH3, OH, and imidazole)). The new amphiphiles quantitatively self-assemble into ≈2 nm-sized aromatic micelles in water independent of the side-chain. Importantly, efficient water-solubilization and nonionic surface modification of various nanocarbons (e.g., fullerene C60, carbon nanotubes, and graphene nanoplatelets) are achieved through noncovalent encircling with the bent amphiphiles. The resultant imidazole-modified nanocarbons display a pH-responsive surface charge, as evidenced by NMR and zeta-potential measurements. In addition, solubilization of a nitrogen-doped nanocarbon (i.e., graphitic carbon nitride) in the form of 10-30 nm-sized stacks is also demonstrated using the present amphiphiles.
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