Synthesis, Characterization, and Reactivity of Iron(III) Complexes Supported by a Trianionic ONO3鈥?/sup> Pincer Ligand
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- 作者：Matias E. Pascualini ; Natali V. Di Russo ; Pedro A. Quintero ; Annaliese E. Thuijs ; Dawid Pinkowicz ; Khalil A. Abboud ; Kim R. Dunbar ; George Christou ; Mark W. Meisel ; Adam S. Veige
- 刊名：Inorganic Chemistry
- 出版年：2014
- 出版时间：December 15, 2014
- 年：2014
- 卷：53
- 期：24
- 页码：13078-13088
- 全文大小：632K
- ISSN：1520-510X
文摘
Synthetic and characterization results of a new family of Fe(III) compounds stabilized by a trianionic [CF3鈥揙NO]3鈥?/sup> pincer-type ligand are reported. The ligand possesses three negatively charged donors constrained to the meridional positions that provide sufficient electron density to stabilize high-valent metal complexes. Using the redox-insulated [CF3鈥揙NO]3鈥?/sup>, pentacoordinated square-pyramidal {[CF3鈥揙NO]FeCl2}{LiTHF2}2 (3), dimeric 渭-DME{[CF3鈥揙NO]FeDME}2 (4), trigonal bipyramidal [CF3鈥揙NO]Fe(bpy) (5), and octahedral [CF3鈥揙NO]Fe(bpy)H2O (5路H2O) complexes are synthesized. An interesting feature of the [CF3鈥揙NO]3鈥?/sup> pincer-type ligand is its ability to coordinate the metal center in both the more common meridional positions or occupying a face of a trigonal bipyramidal complex. The molecular structure of 3 contains structural features similar to those of a rare square-planar high-spin Fe(II) complex, and the important role of the counterions in stabilizing a square-plane is emphasized. SQUID magnetometry measurements of 3 reveal its high-spin character, and cyclic voltammetry measurements indicate high oxidation state species are unstable. However, all compounds can be reduced, and in particular 5 displays a reversible reduction event at 鈭?255 mV versus ferrocene (Fc+/Fc) that can be assigned to either the FeI/Fe0 couple or 2,2鈥?bipyridine reduction.