Metal-Ligand Interactions and Oligo(p-phenylene vinylene) Derivatives Based Supramolecular Polymer Possessing Variable Fluorescence Colors

Abstract

Fluorescent supramolecular polymers combine the benefits of supramolecular polymers in terms of dynamic nature with the optoelectronic features of incorporated fluorophores. However, the majority of fluorescent supramolecular polymers can only exhibit a single fluorescent state, restricting their applications. Incorporating J-type dyes into supramolecular monomers is expected to impart supramolecular polymers with variable fluorescence colors, because the aggregation mode of J-type dyes is closely related to the formation of supramolecular polymers. Herein, the authors report a supramolecular polymer [M1·Zn(OTf)₂ ]_n , in which the monomer M1 contains a J-type dye, oligo(p-phenylene vinylene) derivative, and two terpyridine ends. The M1 + Zn(OTf)₂ solutions exhibit fluorescence color changes varying from cyan to yellow-green in the monomer concentration ranging from 0.04 to 1.00 mm. Moreover, based on the outputs from laser scanning confocal microscopy, the fluorescence color transition during the formation of supramolecular polymers is intuitively proven. Additionally, considering the close relationship between the supramolecular polymer structure and the fluorescence color, the fluorescence color can be regulated by introducing tetraethylammonium hydroxide that can bind with Zn²⁺ competitively to break up the structure of the supramolecular polymer.

Keywords: J-aggregation; fluorescence; self-assemblies; supramolecular polymers.