Co-crystalline hydrogen bonded solids based on the alcohol-carboxylic acid-alcohol supramolecular motif

The helical tubuland diol 4 forms 1:1 hydrogen bonded co-crystalline adducts with 2-propanol and propanoic acid in space group P2(1)/c, and with benzoic acid in C2/c. In the first of these compounds, the 2-propanol molecules contribute one hydroxy group to the intermolecular ...O-H...O-H...O-H... hydrogen bond repeat unit. The co-crystals formed with propanoic acid and benzoic acid both contain a ...O-H...O=C(R)-O-H...O-H... repeat unit with the hydrogen bonds surrounding a pseudo-threefold screw axis, and where the carboxylic acid group functions like an extended alcohol hydroxy group. Aromatic offset face-face associations also play a significant role in the crystal structure of the benzoic acid compound.