Crystal structures of non-proteinogenic amino acid peroxosolvates: rare example of H-bonded hydrogen peroxide chains

Novel peroxosolvates of the non-proteinogenic amino acids sarcosine C₃H₇NO₂·H₂O₂ (1) and phenylserine C₉H₁₁NO₃·H₂O₂ (2) were prepared and their structures were determined by X-ray crystallography. All «active» hydrogen atoms (amino, hydroxo, and peroxo) in these adducts are involved in hydrogen bonding. All H₂O₂ molecules form two donor hydrogen bonds HOOH⋯⁻O₂C–. In contrast to the widely studied structures of natural amino acid peroxosolvates, in structure 2 charge-assisted NH⁺⋯O₂H₂ hydrogen bonds were not found. Crystal 2 represents a rare example of peroxide molecules combined in infinite H-bonded chains.