DL-Piperidinium-2-carboxylate bis(hydrogen peroxide): Unusual hydrogen-bonded peroxide chains

The title compound, C₆H₁₁NO₂·2H₂O₂, is the richest (by molar ratio) in hydrogen peroxide among the peroxosolvates of aliphatic α-amino acids. The asymmetric unit contains a zwitterionic pipecolinic acid molecule and two hydrogen peroxide molecules. The two crystallographically independent hydrogen peroxide molecules form a different number of hydrogen bonds: one forms two as donor and two as acceptor ([2,2] mode) and the other forms two as donor and one as acceptor ([2,1] mode). The latter hydrogen peroxide molecule forms infinite hydrogen-bonded hydroperoxo chains running along the c-axis direction, which is unusual for aliphatic α-amino acid peroxosolvates.