Anthracene and pyrene containing fluorescent metallacycles/cages (MOCs) and their applications

Metal–organic cycle/cages (MOCs) are a class of molecular structures characterized by their unique shapes and dimensions, created using the systematic combination of an organic donor and a metal center. Due to their versatile properties, MOCs are highly useful in materials science. Owing to their unique structural and photoelectric properties, polycyclic aromatic hydrocarbons have significant application potential in optoelectronic devices, chemical sensing, and biomedical fields. Fluorescent MOCs constructed with aromatic units such as anthracene and pyrene as backbones show unique fluorescence properties and have broad applications in molecular recognition, sensing, bioimaging, and functional materials. This review highlights the latest research progress on these materials in multiple areas, including luminescence, resonance fluorescence energy transfer, host–guest chemistry, molecular recognition, and bioimaging. In addition, design strategies and related applications of MOCs involving conformational distortions and cycloaddition reactions are discussed. This review provides a summary of the advances in this field during the past three years.