We report an application of co-milling to the binary cocrystal (BZQ)·(HQ) or commonly known as quinhydrone. The co-milling is performed with either trans -bis(4-pyridyl)ethylene (4.4′-BPE) or 4-methoxyaniline (4-MA) . In both cases, the dark green color of (BZQ)·(HQ) in the sample undergoes discoloration with the co-milling. Sublimation of BZQ occurs with dismantling of (BZQ)·(HQ) to allow for formation of the targeted cocrystals (HQ)·(4,4′-BPE) and (HQ)·2(4-MA) .
Ezekiel et al. (Sun,) studied this question.