Chemistry from the Pilgrim group featured in IChO 2025 question

Chemistry from the Pilgrim group was featured in a final theory paper at the International Chemistry Olympiad (IChO) 2025. Students had to use their knowledge of stereochemistry to determine both the symmetry properties (chiral/achiral) and the number of possible isomers of various possible ligand combinations in lantern metal-organic cages. The question is based on an analysis conducted as part of our publication J. Am. Chem. Soc. 2024, 146, 28233-28241. Under exam conditions the best student got the final table almost correct (just a single mistake). Have a go yourself and see how you do... https://www.icho2025.ae/problems