Axial and helical chirality in multinuclear group 13 complexes: pathways to functional optical materials

Main-group element complexes have emerged as promising functional dyes owing to their unique photophysical properties and potential applications in sensors, luminescent devices, and photocatalysis. Among these, multinuclear main-group complexes that incorporate multiple elements within a single ligand have garnered significant attention, particularly for their ability to exhibit chirality with optical functions. Axial and helical chirality, resulting from unique coordination geometries, represent a critical frontier in the design of functional materials. These complexes enable diverse functionalities, including circular dichroism and circularly polarized luminescence. This Frontier article highlights recent advances in the synthesis of multinuclear main-group element complexes with chirality, focusing on their structural uniqueness and photochemical characteristics. Particular emphasis is placed on group 13 element complexes, including boron(III), aluminum(III), gallium(III), and indium(III), which exhibited unique chiral properties and photophysical behaviors. Key topics include the design strategies for chiral multinuclear frameworks, their photophysical properties, and their integration into advanced functional materials.