Hydrogen Peroxide Insular Dodecameric and Pentameric Clusters in Peroxosolvate Structures

Area of Science:

• Crystal engineering
• Supramolecular chemistry
• Hydrogen peroxide chemistry

Background:

• Hydrogen peroxide (H₂O₂) is a versatile chemical with diverse applications.
• Understanding the self-assembly of H₂O₂ in crystalline solids is crucial for controlling its properties.
• Peroxosolvates, crystalline structures incorporating H₂O₂, offer a unique platform for studying H₂O₂ behavior.

Purpose of the Study:

• To isolate and characterize novel peroxosolvates of 2-aminonicotinic acid and lidocaine N-oxide.
• To investigate the structural diversity of hydrogen peroxide clusters within these crystals.
• To explore new hydrogen bonding motifs involving hydrogen peroxide.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the precise atomic arrangements.
• Isolation and crystallization of peroxosolvates of 2-aminonicotinic acid (I) and lidocaine N-oxide (II).
• Analysis of hydrogen peroxide cluster topologies and hydrogen bonding networks.

Main Results:

• An unprecedented dodecameric hydrogen peroxide cluster was identified in 2-aminonicotinic acid peroxosolvate (I).
• An unusual cross-like pentameric hydrogen peroxide cluster was observed in lidocaine N-oxide peroxosolvate (II).
• New instances of double and triple cross-orientational disorder of H₂O₂ were discovered in both compounds. Cluster II represents the first peroxosolvate with a homoleptic H₂O₂ environment and features a novel hydrogen bond between H₂O₂ and a peptide group.

Conclusions:

• The study reveals novel supramolecular architectures of hydrogen peroxide in crystalline states.
• The findings expand the known structural diversity of hydrogen peroxide clusters and their interactions.
• This research provides new insights into the hydrogen bonding capabilities of H₂O₂ in organic crystal structures.