The curious case of proton migration under pressure in the malonic acid and 4,4'-bipyridine cocrystal.

ABSTRACT: In the search for new active pharmaceutical ingredients, the precise control of the chemistry of cocrystals becomes essential. One crucial step within this chemistry is proton migration between cocrystal coformers to form a salt, usually anticipated by the empirical ΔpK_a rule. Due to the effective role it plays in modifying intermolecular distances and interactions, pressure adds a new dimension to the ΔpK_a rule. Still, this variable has been scarcely applied to induce proton-transfer reactions within these systems. In our study, high-pressure X-ray diffraction and Raman spectroscopy experiments, supported by DFT calculations, reveal modifications to the protonation states of the 4,4'-bipyridine (BIPY) and malonic acid (MA) cocrystal (BIPYMA) that allow the conversion

SUBMITTER: Patyk-Kazmierczak E 

PROVIDER: S-EPMC10916288 | biostudies-literature | 2024 Mar

REPOSITORIES: biostudies-literature