Supramolecular Synthon Frustration Leads to Crystal Structures with Z′ > 1

A systematic study into frustration in compounds participating in more than one supramolecular synthon or simultaneously belonging to other categories such as hydrates, co-crystals or crystallizing in a chiral space groups has been undertaken using the Cambridge Structural Database (CSD). The study shows that the combination of more than one directional synthon or the combination of directional synthons with other particular categories of molecule results in markedly increased percentages of structures with Z ′ > 1. The majority of combinations show percentages higher than the CSD average of 8.8% and some cases have Z′ > 1 percentages in excess of 60% such as the combination of a carboxylic acid dimer and a molecule in a chiral space group (64.7%). Individual cases have been highlighted and outliers have been discussed and resolved.