A new olanzapine cocrystal obtained from volatile deep eutectic solvents and determined by 3D electron diffraction

A previously unknown cocrystal of olanzapine and phenol was identified from a volatile deep eutectic solvent as the intermediate species in the crystallization of olanzapine. This new nanocrystalline phase was investigated by electron diffraction, powder X-ray diffraction and differential scanning calorimetry. The structure was determined by simulated annealing using 3D electron diffraction data and confirmed using DFT-D optimizations. Olanzapine and phenol cocrystallize in the triclinic space group P (1) over bar, supporting the hypothesis of a dimeric growth unit, where a centrosymmetric dimer is stabilized by multiple weak C-H center dot center dot center dot pi interactions and forms double N-H center dot center dot center dot N hydrogen bonding with adjacent dimers.