Establishing the Analogy between Hydrates and Peroxosolvates: Cambridge Structural Database Analysis of Pyridyl Hydrates Yields New Peroxosolvates
Taylor A. Bramlett, Leila M. Foroughi, Adam J. Matzger
Abstract
Non-covalent interactions are critical components in the synthetic toolbox to modulate self-assembly processes and molecular recognition. Hydrogen bonding is most commonly employed because of the strong and directional interactions that can be designed. In recent years, studies to improve the properties of active pharmaceutical ingredients (APIs) and energetic materials have explored incorporating hydrogen peroxide into molecular design strategies to improve physical and chemical properties relative to hydrates. Herein, the structural similarities between water and hydrogen peroxide were leveraged using hydrate identification from the Cambridge Structural Database (CSD) to identify hydrogen peroxide solvate (peroxosolvate) formation with pyridines. The CSD search yielded eight commercially available pyridine hydrates that, under various crystallization conditions, successfully produced eight new peroxosolvates (pyridyl or derived from the corresponding N -oxides). The obtained solvates were characterized by Raman spectroscopy, and for six peroxosolvates the structures were determined by single-crystal X-ray diffraction. The peroxosolvate structural data were compared with the known hydrate structures to analyze hydrogen bonding and packing motifs. The success in obtaining new peroxosolvates validates the predictive power of hydrate structures for identifying potential peroxosolvate formation.