Non-conventional Liquid-Crystalline Columnar Assemblies Based on Organic Dyes

Abstract

Herein we present two new core N-substituted Naphthalene diimides (NDIs) (1 and 2) that form unprecedented columnar liquid-crystalline (LC) J-aggregates. NDI-1 spontaneously assembles into an unconventional columnar J-aggregate where the dyes organize with the cores parallel to the columnar axis via hydrogen bonds and slipped π-π interactions. On the other hand, NDI-2 self-assembles into conventional columnar LC H-aggregates, but its conversion into J-aggregates was achieved by mechanical shearing of the sample, which induces a blue shift of the main absorption band and a fluorescence light-up. We describe for a first-time the preparation of LC NDI J-aggregates with great potential as optical materials.