A solvent-free organic synthesis from solid-state reactants through autogenous fusion due to formation of molecular complexes and increasing alcohol nucleophilicity

Crystalline imidazole (IM, mp 361-364 K) fuses autogenously immediately after making contact at room temperature with menthol (MT, mp 316 K) as a consequence of the hydrogen bond. Autogenous fusion is triggered by the recombination of the hydrogen bonds from the homogeneous ones (MT-MT) stabilizing MT crystals to the heterogeneous ones between OH of MT and N of IM to form an intermediate molecular complex at a eutectic composition. Formation of molecular complex parallels the increase in the nucleophilic affinity of MT by the intermolecular hydrogen bonds, as confirmed by the peak shift of 1H NMR as well as by DFT computation.