Unique three‐component co‐assembly among AIEgen, L‐GSH, and Ag⁺ for the formation of helical nanowires

Abstract

Nature has selected, produced, and evolved numerous molecular architectural motifs over billions of years for particular bio-functions. During this process, molecular self-assembly plays a critically important role. Inspired by these delicate assemblies, scientists devote themselves to developing various sophisticated complexes assembled by diverse and numerous structural motifs. By far, most of the examples focus on single-molecule self-assembly or co-assembly between two molecules, seldom works report the co-assembly among three building blocks due to the substantially increased complexity and decreased controllability. Here we report a novel three-component co-assembly among L-glutathione (L-GSH), AgNO 3 , and an aggregation-induced emission luminogen (AIEgen), namely triphenylaminepyridinium (abbreviated to TPA-Py). TPA-Py, L-GSH, and Ag + co-assemble into numerous long and ordered nanowires with left-handed helices, which show remarkable AIE properties that can be observed by naked eyes. This effect is only detected in this system, the replacement of TPA-Py with other AIEgens, L-GSH with other cysteine derivatives or anions, Ag + with other metal ions, could not lead to the unique AIE effect, which endows this system with high specificity and controllability. This work provides new insight into the design of biomolecule recognition systems and discloses that ternary co-assembly could become a facile route to build sophisticated nanobiomaterials.

Synthesis of Helical Indolophenanthridines Showing Aggregation-Induced Emission

“…On the basis of these results, an aggregation-enhanced/-induced emission (AEE/AIE) behavior can be assumed. This behavior is studied extensively and attributed to various, not completely understood mechanisms inter alia to a restricted intramolecular rotation or motion (RIR or RIM) in the aggregates . While nonaggregated helicenes 13d and 22d should be prone to racemization at room temperature, this conformational change might be prevented by aggregation, which results in increased emission.…”