Hydrogen peroxide adducts of triarylphosphine oxides

Five new hydrogen peroxide adducts of phosphine oxides ( p -Tol 3 PO·H 2 O 2 ) 2 ( 1 ), ( o -Tol 3 PO·H 2 O 2 ) 2 ( 2 ), ( o -Tol 2 PhPO·H 2 O 2 ) 2 ( 3 ), ( p -Tol 3 PO) 2 ·H 2 O 2 ( 4 ), and ( o -TolPh 2 PO) 2 ·H 2 O 2 ( 5 ), and the water adduct ( o -Tol 2 PhPO·H 2 O) 2 ( 6 ) have been synthesized and fully characterized. Their single crystal X-ray structures have been determined and analyzed. The IR and 31 P NMR data are in accordance with strong hydrogen bonding of the hydrogen peroxide. The mono- versus dimeric nature of the adduct assemblies has been investigated by DOSY NMR experiments. Raman spectroscopy of the symmetric adducts and the ν (O-O) stretching bands confirm the presence of hydrogen-bonded hydrogen peroxide in the solid materials. The solubilities in organic solvents have been quantified. Due to the high solubilities of 1-6 in organic solvents their 17 O NMR spectra could be recorded in natural abundance, providing well-resolved signals for the P&z.dbd;O and O-O groups. The adducts 1-5 have been probed regarding their stability in solution at 105 °C. The decomposition of the adduct 1 takes place by loss of the active oxygen atoms in two steps. Five new safe, solid, and soluble H 2 O 2 adducts of triarylphosphine oxides, including the displayed ( p -Tol 3 PO·H 2 O 2 ) 2 , have been synthesized and characterized.