Triphenylamine-Based Supramolecular Coordination Metallacycles.

Over the past two decades, triphenylamine (TPA)-based supramolecular coordination metallacycles, constructed by incorporating TPA and its derivatives as key building blocks into two-dimensional (2D) coordination-driven assemblies, have gradually received considerable attention and emerged as an important research topic within the field of discrete supramolecular coordination complexes (SCCs). Leveraging the synthetic accessibility and outstanding optoelectronic properties of TPA units, the resulting TPA-based metallacycles exhibit well-defined topological structures, excellent emission characteristics, and unique functions. In this review, we systematically and comprehensively discuss the design strategies, synthetic methodologies, and practical applications for TPA-based supramolecular metallacycles, with an emphasis on five key aspects: (i) coordination-driven self-assembly, (ii) hierarchical self-assembly, (iii) supramolecular polymers, (iv) tunable fluorescence, and (v) diverse applications. Finally, future perspectives and challenges in this rapidly evolving field are presented.