Hydrogen bond directed supramolecular arrays utilising hemimellitic acid: Solvent inclusion clathrates

Hemimellitic acid (benzene-1,2,3-tricarboxylic acid) has received surprisingly little attention in the field of crystal engineering, despite it possessing three carboxylic acid groups. Here we utilise this robust functionality in the creation of hydrogen bonding arrays within which solvent molecules (methanol, ethanol, 1-propanol, 2-propanol, 2-methylpropan-2-ol, acetonitrile and acetone) are enclosed. The nature of the solvent of crystallisation (and hence inclusion) allows the hydrogen bonding networks to adopt various architectures including the common brick-wall and herringbone arrangements. The supramolecular hydrogen bonding motifs within the arrays are identified using Etter's graph set analysis.