Diphane: A Cage-like Compound Featuring Two Cavities

Diphane refers to cage-like compounds featuring two discrete cavities, which are capable of selectively encapsulating and/or discriminating multiple guest molecules. This unique dual-cavity design could enable versatile applications in molecular recognition, separation, multiphase catalysis, and adsorption. In this review, we present a timely overview of synthetic strategies for diphanes with diverse shapes and functions. We emphasize two main synthetic approaches: covalent (reversible and irreversible) and coordination-driven (metal-organic) strategies. By highlighting recent advances in the rational design and functional applications of diphanes, this review aims to inspire further exploration of double- and multiple-chambered molecular cages—particularly in developing new synthetic strategies and expanding their structural diversity and functions.