Synthesis, Characterization, and Reactivity of Iron Trisamidoamine
Complexes That Undergo Both Metal- and Ligand-Centered Oxidative
Transformations
Remle Çelenligil-Çetin
Patrina Paraskevopoulou
Rupam Dinda
Richard J. Staples
Ekkehard Sinn
Nigam P. Rath
Pericles Stavropoulos
10.1021/ic702154z.s020
https://acs.figshare.com/articles/dataset/Synthesis_Characterization_and_Reactivity_of_Iron_Trisamidoamine_Complexes_That_Undergo_Both_Metal_and_Ligand_Centered_Oxidative_Transformations/2959960
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 [(RNC<sub>6</sub>H<sub>4</sub>)<sub>3</sub>N]<sup>3-</sup> (L<sup>1</sup>). When R is the electron-rich 4-<i>t</i>-Bu−Ph moiety, the ligand can undergo oxidative
rearrangement and store oxidizing equivalents under specific conditions. Starting ferrous complexes of the general
formula [(L<sup>1</sup>)Fe<sup>II</sup>solv]<sup>-</sup> (solv = CH<sub>3</sub>CN, dimethylformamide) can be easily oxidized (a) by dioxygen to afford the
corresponding [(L<sup>1</sup>)Fe<sup>III</sup>OH]<sup>-</sup> complexes, featuring several cases of terminal hydroxo units, and (b) by organochlorides
(R−Cl) to provide [(L<sup>1</sup>)Fe<sup>III</sup>solv] congeners and coupled R−R products. Efforts to synthesize [(L<sup>1</sup>)Fe<sup>III</sup>−O−Fe<sup>III</sup>(L<sup>1</sup>)]<sup>2-</sup>
by using [Cl<sub>3</sub>Fe<sup>III</sup>−O−Fe<sup>III</sup>Cl<sub>3</sub>]<sup>2-</sup> indicate that intrinsic Fe<sup>III</sup>Cl units can oxidatively rearrange the ligand to afford
[(L<sup>1</sup><sub>re</sub>)(Cl)Fe<sup>II</sup>][Et<sub>4</sub>N]<sub>2</sub>, although the oxidizing equivalent is not retained. Compound [(L<sup>1</sup><sub>re</sub>)(Cl)Fe<sup>II</sup>][Et<sub>4</sub>N]<sub>2</sub> can be further
oxidized to [(L<sup>1</sup><sub>re-2</sub>)(Cl)Fe<sup>III</sup>][Et<sub>4</sub>N] by CH<sub>2</sub>Cl<sub>2</sub>. Finally, oxidation of [(L<sup>1</sup>)Fe<sup>III</sup>solv] by FeCl<sub>3</sub> affords [(L<sup>1</sup><sub>re</sub>H)(Cl)Fe<sup>II</sup>(<i>μ</i>-Cl)<sub>2</sub>Fe<sup>II</sup>(Cl)(L<sup>1</sup><sub>re-2</sub>H)], 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.
2008-02-04 00:00:00
Fe III solv
ligand rearrangement
Fe II solv
noninnocent ligands
CH 3 CN
L 1
Iron Trisamidoamine Complexes
chemical transformations
iron compounds ligated
trisamidoamine ligands
2 Fe II
RNC
chemical oddities
Fe III OH
CH 2 Cl 2
terminal hydroxo units
ferrous complexes
3 N
oxidative rearrangement
FeCl 3
oxidizing equivalent
store oxidizing equivalents
Fe III Cl units