Nonclassical Oxygen Atom Transfer as a Synthetic Strategy: Preparation of an Oxorhenium(V) Complex of the Bis(3,5-di-tert-butyl-2-phenoxo)amide Ligand

Oxo­(triphenylphosphine)­[bis­(3,5-di-tert-butyl-2-phenoxo)­amido]­rhenium­(V) [(ONOCat)­ReO­(PPh3)] is prepared by the reaction of iododioxobis­(triphenylphosphine)­rhenium­(V) [ReO2(PPh3)2I] with lead bis­(3,5-di-tert-butyl-1,2-quinone-1-(2-oxy-3,5-di-tert-butylphenyl)­imine) [Pb­(ONOQ)2]. In this reaction, the ONO ligand undergoes a two-electron reduction, with concomitant oxidation of PPh3 to OPPh3 and transformation of the dioxorhenium­(V) fragment into a monooxorhenium­(V) fragment, constituting a net nonclassical oxygen atom transfer. (ONOCat)­ReO­(PPh3) adopts a square pyramidal geometry with an apical oxo group [dReO = 1.6873(14) Å] and a highly folded ONO ligand [O–Re–O = 129.55(6)°]. The fully reduced, trianionic oxidation state of the ONO ligand is confirmed by spectroscopic and metrical data.