Designing Papercraft Models: Metal–Organic Cages Based on cis-Capped Palladium Building Blocks and Tridentate Bridging Ligands

This report outlines the creation of papercraft models designed to elucidate the rational design and characteristics of metal–organic cages tailored for first-year nonchemistry majors. Metal–organic cages are advanced materials formed by self-assembling metal ions and bridging ligands into cage-like structures. Notable examples include [(en)Pd]₆(4TPT)₄¹²⁺ (1) and [(en)Pd]₆(3TPT)₄¹²⁺ (2) [where en = ethylenediamine, 4TPT = 2,4,6-tri(4-pyridyl)-1,3,5-triazine, and 3TPT = 2,4,6-tri(3-pyridyl)-1,3,5-triazine], exhibiting isomeric properties. Compound 1 features a hollow octahedral structure, while compound 2 adopts a bowl-shaped form, allowing for the encapsulation of small molecules within its cavity. Using cardboard imprinted with molecular structures and supplemented with paper clips, students actively engaged in fabricating papercraft models of compounds 1 and 2. This hands-on approach deepened their comprehension of the rational design principles and small-molecule encapsulation mechanisms inherent in these compounds while reinforcing their understanding of coordination bonds and isomerism fundamentals.