Cooperative Capture Synthesis Broadens Rotaxane Strategy to Improve Solubility, Stability, and Optical Properties of Organic Dyes

Organic dyes play indispensable roles across engineering, materials science, and biomedical technologies, and extensive efforts have been devoted to creating dyes with advanced optical functionalities. Unfortunately, many newly developed dyes suffer from poor stability and limited solubility, severely restricting their practical utility. A strategy based on rotaxane architecture offers a promising solution to these drawbacks by enabling irreversible encapsulation. Nevertheless, conventional rotaxane-type dyes are often difficult to synthesize, thereby narrowing the range of accessible dye structures and slowing progress in the field. To overcome this challenge, we recently established a versatile cooperative capture synthesis that enables efficient access to diverse rotaxane-type dyes. The resulting interlocked dyes exhibit high water solubility and exceptional stability while enhancing key optical properties such as circularly polarized luminescence and photosensitization. This account summarizes our development of rotaxane-type dyes and highlights the unique photophysical and functional advantages imparted by rotaxane architectures.