Exploring the Effect of Temperature on a Mechanochemical Reaction by in Situ Synchrotron Powder X‑ray Diffraction

We describe the first in situ and real-time study of a mechanochemical reaction by variable-temperature synchrotron powder X-ray diffraction. Using the dry milling synthesis of a coordination polymer as a model system, we reveal a change in reaction mechanism if temperature is increased, and a strong dependence of the reaction rate on temperature, with a ca. 6-fold increase of the rate of reactant depletion for a 45 °C rise in temperature. These experiments provide also the first direct evidence how a formally dry milling reaction is facilitated by water released from a hydrated reactant.