Influencing the stoichiometry of Prussian blue analogues using mechanochemistry.

Prussian blue analogues of the general formula AxMn[Co(CN)6]y with A = K, Rb, Cs were synthesised using ball milling. Milling frequency f (10, 30 Hz), reaction time (30-120 min) and the hydration level of the starting material MnCl2·nH2O (n = 2, 4) were varied. Powder X-ray diffraction provides information about the progress of the reaction, as well as the A-site cation occupancy and order. Our results show that mechanochemistry has potential to tune the composition of Prussian blue analogues, and highlight the importance of starting material, frequency, time and identity of the A-site cation.