Construction of supramolecular hexagonal metallacycles via coordination-driven self-assembly: Structure, properties and application

The formation and growth of natural objects are affected by the available space and materials. A regular hexagon is one of three regular polygons that can overlap without a plane. Among these three regular polygons (equilateral triangle, regular quadrilateral, and regular hexagon), the regular hexagon occupies the largest area with the smallest amount of material. The construction of supramolecular hexagonal architectures has been of great interest within supramolecular chemistry and materials science. Since supramolecular self-assembly enables the preparation of highly complex supramolecular systems from relatively simple building blocks, various metallosupramolecular hexagonal architectures have been successfully constructed under mild conditions by employing facile coordination-driven self-assembly strategy, and some of the architectures have exhibited wide ranges of applications in the fields of catalysis, electrochemistry, photochemistry, molecular sensing, etc. This review summarizes recent advances in the field of supramolecular hexagonal metallacycles. The design, self-assembly, and applications of various supramolecular hexagonal metallacycles, especially those incorporating functional moieties, will be discussed.