@article{2928862,
    title = "Synthesis, Characterization, and Reactivity of Iron Trisamidoamine Complexes That Undergo Both Metal- and Ligand-Centered Oxidative Transformations",
    author = "Remle Celenligil-Cetin and Patrina Paraskevopoulou and Rupam Dinda and Richard J. Staples and Ekkehard Sinn and Nigam P. Rath and Pericles Stavropoulos",
    journal = "International Journal of Inorganic Chemistry",
    year = "2008",
    volume = "47",
    number = "3",
    pages = "1165--1172",
    publisher = "American Chemical Society (ACS)",
    doi = "10.1021/ic702154z",
    abstract = "Functional systems that combine redox-active metals and noninnocent
ligands are no longer rare chemical oddities; they are instead emerging
as significant components of catalytic and enzymatic reactions. The
present work examines the synthetic and functional aspects of iron
compounds ligated by a family of new trisamidoamine ligands of the type
[(RNC6H4)(3)N](3-) (L-1). When R is the electron-rich 4-t-Bu-Ph
moiety, the ligand can undergo oxidative rearrangement and store
oxidizing equivalents under specific conditions. Starting ferrous
complexes of the general formula [(L-1)Fe(II)solv](-) (solv = CH3CN,
dimethylformamide) can be easily oxidized (a) by dioxygen to afford the
corresponding [(L-1)(FeOH)-O-III](-) complexes, featuring several
cases of terminal hydroxo units, and (b) by organochlorides (R-Cl) to
provide [(L-1)Fe(III)solv] congeners and coupled R-R products. Efforts
to synthesize [(L-re(1))Fe-III-O-Fe-III(L-1)](2-) by using
[Cl3FeIII-O-(FeCl3)-Cl-III](2-) indicate that intrinsic (FeCl)-Cl-III
units can oxidatively rearrange the ligand to afford
[(L-re(1))(Cl)Fe-II][Et4N](2), although the oxidizing equivalent is
not retained. Compound [(L-re(1)) (Cl) Fe-II][Et4N](2) can be
further oxidized to [(L-re-2(1))(Cl)Fe-III][Et4N] by CH2Cl2.
Finally, oxidation of [(L-1)Fe(III)solv] by FeCl3 affords
[((LreH)-H-1)(Cl)Fe-II(mu-Cl)(2)Fe-II(Cl)((Lre-2H)-H-1)], which
features a similar ligand rearrangement that also gives rise to a
diamagnetic, doubly oxidized moiety. These results underscore the
complexity of chemical transformations available to systems in which
both the metal and the ligand are redox-active entities."
}