Dioxygen oxidation of a carbonyl ligand to form a chelating peroxycarbonyl ligand: synthesis, structure, and reactions of Cl(NO)(PPh 3) 2

Abstract

Reaction between the carbonyl, nitrosyl complex, OsCl(CO)(NO)(PPh 3) 2 ( 1) and dioxygen results in combination of CO and O 2, forming a chelating peroxycarbonyl ligand in the yellow complex, ▪Cl(NO)(PPh 3) 2 ( 2). Confirmation of the unique peroxycarbonyl ligand arrangement in 2 is provided by crystal structure determination. When 2 is heated, as a suspension in heptane under reflux, there is a rearrangement to the regular chelating carbonate ligand in the orange complex, ▪Cl(NO)(PPh 3) 2 ( 3). The structure of 3 has also been determined by X-ray crystallography. Compound 2 also undergoes the following reactions: with water, releasing CO 2 and forming Os(OH) 2Cl(NO)(PPh 3) 2 ( 4); with HCl releasing CO 2 and forming Os(OH)Cl 2(NO)(PPh 3) 2 ( 5); and with excess triphenylphosphine releasing CO 2 and triphenylphosphine oxide forming OsCl(NO)(PPh 3) 3 ( 6).