Polymorphs of a 1:1 cocrystal with tunnel and layer structures:: pp′-biphenol/dimethyl sulfoxide

Two polymorphs of the 1:1 cocrystal formed between p,p'-biphenol and dimethyl sulfoxide (DMSO) have been discovered. One polymorph has a tunnel type structure, which can be considered to comprise tunnels formed from p,p'-biphenol molecules accommodating the DMSO molecules as guests. The other polymorph has a layered structure, comprising layers of p,p'-biphenol molecules and layers of DMSO molecules. In both structures, there is direct hydrogen bonding between the p,p'-biphenol and DMSO components of the cocrystal. The general utility of the p,p'-biphenol molecule as a component in crystal engineering strategies is discussed.