Transient Formation and Reactivity of a High-Valent Nickel(IV) Oxido Complex

A reactive high-valent dinuclear nickel(IV) oxido bridged complex is reported that can be formed at room temperature by reaction of [(L)2Ni(II)2(mu-X)3]X (X = Cl or Br) with NaOCl in methanol or acetonitrile (where L = 1,4,7-trimethyl-1,4,7-triazacyclononane). The unusual Ni(IV) oxido species is stabilized within a dinuclear tris-mu-oxido-bridged structure as [(L)2Ni(IV)2(mu-O)3]2+. Its structure and its reactivity with organic substrates are demonstrated through a combination of UV–vis absorption, resonance Raman, 1H NMR, EPR, and X-ray absorption (near-edge) spectroscopy, ESI mass spectrometry, and DFT methods. The identification of a Ni(IV)-O species opens opportunities to control the reactivity of NaOCl for selective oxidations.The results were published today in Journal of the American Chemical Society (J. Am. Chem. Soc. 2017, 139, 8718-8724):
S.K. Padamati, D. Angelone, A. Draksharapu, G. Primi, D.J. Martin, M. Tromp, M. Swart, and W.R. Browne
“Transient Formation and Reactivity of a High-Valent Nickel(IV) Oxido Complex”
J. Am. Chem. Soc. 2017, 139, 8718-8724 [abstract]
DOI: 10.1021/jacs.7b04158