Accessing new polymorphs and solvates through solvothermal recrystallization

In high-pressure structural chemistry, recrystallization techniques have been shown to be a powerful way of generating new polymorphs and solvates. A recent study by Olejniczak et al. [IUCrJ (2022), 9, 49-54] on the pyridazine-based compound 6-chloro-1,2,3,4-tetrazolo[1,5-b]pyridazine (C(4)H(2)N(5)Cl or CTP) uses these solvothermal techniques to establish the phase behaviour of CTP and the effects of partial hydration.