Mechanochemical Reactions of Cocrystals: Comparing Theory with Experiment in Making and Breaking Halogen Bonds in Solid State

Mechanochemical re-investigation of the halogen-bonded cocrystallization of 1,4-diazabicyclo[2.2.2]octane and 1,2-diiodotetraflurobenzene revealed an unexpectedly complex system, with three distinct cocrystal compositions, one of which also exhibits temperature-dependent polymorphism. This provided an opportunity to experimentally test the ability of dispersion-corrected periodic density functional theory (DFT) not only to explain the formation, but also predict the interconversion between halogen-bonded cocrystals of different stoichiometries,