Abstract
<jats:p>The development of synthetic molecular receptors that selectively bind structurally complex, high-value cargoes remains a key challenge in supramolecular chemistry. Heteroleptic self-assembly is a promising approach for constructing complex metal-organic cages from simple subunits, however this technique requires precise ligand size matching to outcompete homoleptic self-assembly. Here, we present a strategy to overcome this constraint by leveraging the flexible quadrilateral geometry of a tetramine subcomponent with naphthalene arms that can change its geometry through rotary motion. By dynamically adjusting its side lengths, this tetramine can accommodate three triamines with increasingly larger sizes, leading to the favourable formation of three heteroleptic triangular prismatic cages over their homoleptic analogues. These structures demonstrate the ability of the tetramine to integrate into different structures by adopting a range of conformations with different edge lengths. This approach provides a strategy for constructing diverse molecular receptors from similar building blocks, reducing the effort required for design and synthesis.</jats:p>