Controlling Self-Assembly Mechanisms through Rational Molecular Design in Oligo(p-phenyleneethynylene)-Containing Alkynylplatinum(II) 2,6-Bis(N-alkylbenz-imidazol-2′-yl)pyridine Amphiphiles

Abstract

The systematic control over association mechanisms of self-assembled materials has been demonstrated through the rational design and synthesis of a series of amphiphilic dinuclear alkynylplatinum(II) bzimpy (bzimpy = 2,6-bis(N-alkylbenzimidazol-2′-yl)pyridine) complexes containing the shape-persistent oligo(p-phenyleneethynylene)s. Multi-stage morphological transformations from plates to fibers and to spherical nanostructures under different solvent compositions have been demonstrated. The subtle balances between multiple noncovalent interactions including Pt···Pt, hydrophobic, hydrophilic, and  stacking interactions are found to have profound impact on the supramolecular assembly of the system, in which a change in the association mechanism from isodesmic to cooperative and back to isodesmic growth has been observed upon increasing hydrophilicity of the complexes.1 Reference: 1. Chan, M. H.-Y.; Leung, S. Y.-L.; Yam, V. W.-W. J. Am. Chem. Soc., 2018, 140, 7637.