Geometric and electronic structure and reactivity of a mononuclear "side-on" nickel(III)-peroxo complex.
Metal-dioxygen adducts, such as metal-superoxo and -peroxo species, are key intermediates often detected in the catalytic cycles of dioxygen activation by metalloenzymes and biomimetic compounds. The synthesis and spectroscopic characterization of an end-on nickel(II)-superoxo complex with a 14-membered macrocyclic ligand was reported previously. Here we report the isolation, spectroscopic characterization, and high-resolution crystal structure of a mononuclear side-on nickel(III)-peroxo complex with a 12-membered macrocyclic ligand, [Ni(12-TMC)(O(2))](+) (1) (12-TMC = 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane). Different from the end-on Ni(II)-superoxo complex, the Ni(III)-peroxo complex is not reactive in electrophilic reactions, but is capable of conducting nucleophilic reactions. The Ni(III)-peroxo complex transfers the bound dioxygen to manganese(II) complexes, thus affording the corresponding nickel(II) and manganese(III)-peroxo complexes. The present results demonstrate the significance of supporting ligands in tuning the geometric and electronic structures and reactivities of metal-O(2) intermediates that have been shown to have biological as well as synthetic usefulness in biomimetic reactions.
Cho
Jaeheung
J
Department of Chemistry and Nano Science, Center for Biomimetic Systems, Ewha Womans University, Seoul, Korea.
Sarangi
Ritimukta
R
Annaraj
Jamespandi
J
Kim
Sung Yeon
SY
Kubo
Minoru
M
Ogura
Takashi
T
Solomon
Edward I
EI
Nam
Wonwoo
W
D018360:Crystallography, X-Ray; D004583:Electrons; D008024:Ligands; D047028:Macrocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D008345:Manganese / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry*; D011789:Quantum Theory
D008024:Ligands; D047028:Macrocyclic Compounds; D009942:Organometallic Compounds; D008345:Manganese; D009532:Nickel; D010100:Oxygen