Organoantimony Dihydroperoxides: Synthesis, Crystal Structures, and Hydrogen Bonding Networks

Area of Science:

• Inorganic Chemistry
• Materials Science
• Organometallic Chemistry

Background:

• The chemistry of inorganic hydroperoxides, particularly p-block hydroperoxo complexes, is underexplored.
• Single-crystal structures of antimony hydroperoxo complexes have not been previously reported.

Purpose of the Study:

• To synthesize and characterize novel antimony dihydroperoxide complexes.
• To investigate the structural features, specifically hydrogen bonding, within these complexes.
• To evaluate the potential of these compounds as oxidants in organic synthesis.

Main Methods:

• Synthesis of six triaryl and trialkylantimony dihydroperoxides via reaction of dibromide antimony(V) complexes with hydrogen peroxide and ammonia.
• Characterization using single-crystal and powder X-ray diffraction, spectroscopy (FTIR, Raman), and thermal analysis.
• Solid-state density functional theory (DFT) calculations to assess hydrogen bonding energy.

Main Results:

• Successfully synthesized six antimony dihydroperoxide compounds with varying organic substituents and solvent adducts.
• Crystal structures revealed extensive hydrogen-bonded networks, including novel infinite hydroperoxo chains.
• DFT calculations confirmed strong hydrogen bonding between hydroperoxo ligands (35 kJ/mol).
• Investigated the potential of Ph3Sb(OOH)2·0.75(C4H8O) as a two-electron oxidant for enantioselective epoxidation.

Conclusions:

• This study reports the first single-crystal structures of antimony hydroperoxo complexes.
• Novel hydrogen-bonding motifs, including infinite chains, were discovered in these compounds.
• Antimony dihydroperoxides show promise as oxidants in enantioselective epoxidation reactions.