A seven-coordinate iron platform and its oxo and nitrene reactivity

作者：Soo Han Sen; Sougrati Moulay T; Grandjean Fernande; Long Gary J; Chang Christopher J^*

来源：Inorganica Chimica Acta, 2011, 369(1): 82-91.

DOI：10.1016/j.ica.2010.12.040

• Pentagonal bipyramidal
• Seven-coordinate
• High-spin iron
• Mossbauer spectroscopy
• Oxo and nitrene transfer

We present a new structurally determined seven-coordinate iron platform supported by the tris(2-picolyl)amine ligand 6,6'-(pyridin-2-ylmethylazanediyl)bis(methylene) bis(N-tert-butylpicolinamide) (TPA(2C(O)NHtBu), 3) and its reactivity with oxo and nitrene transfer agents. Oxidation of the pentagonal bipyramidal, seven-coordinate iron(II)-triflate complex [TPA(2C(O)NHtBu)Fe(II)(OTf)][OTf] (4) with PhIO produces the corresponding diiron(III) mu-oxo complex [(TPA(2C(O)NHtBu)Fe(III))(2)(O)][OTf](4) (5). Mossbauer and magnetic measurements on 5 in the solid-state establish antiferromagnetic coupling between its two Fe(III) centers. Reactions of 4 with the nitrene transfer agents PhINTs (Ts = p-MeC6H4SO2) and PhINNs (Ns = p-NO2C6H4SO2) provide the corresponding iron(III)-amide congeners [TPA(2C(O)NHtBu)Fe(III)(NHTs)][OTf](2) (6) and [TPA(2C(O)NHtBu)Fe(III)(NHNs)][OTf](2) (7), respectively, affording a rare pair of isolable Fe(III)-amide compounds formed from nitrene transfer. By characterizing well-defined products in the crystalline form, derived from atom and group transfer to seven-coordinate iron, the collective data provide a starting point for the exploration of high-valent and metal-ligand multiply bonded species supported by approximate pentagonal-type ligand fields.

• 出版日期2011-4-15