Mn^IV-Oxo complex of a bis(benzimidazolyl)-containing N5 ligand reveals different reactivity trends for Mn^IV-oxo than Fe^IV-oxo species

Abstract

Investigations of a MnIV-oxo adduct supported by an N5 ligand with mixed pyridyl and benzimidazolyl ligation uncovers distinct reactivity trends for MnIV-oxo and FeIV-oxo adducts at parity of coordination sphere.

Structural Characterization of a Series of N5‐Ligated MnIV‐Oxo Species

“…The newly collected data were fit with two or three pseudo‐Voigt functions (Figure S1, Supporting Information), giving pre‐edge areas similar to those reported previously (Table ). The exception is the pre‐edge area for [Mn IV (O)(2pyN2B)] 2+ , which is now 22.2, a dramatic increase compared to the previously reported value of 14.6 . This increase in pre‐edge area, along with the higher‐edge energy of the present sample (6550.2 versus 6549.6 eV), leads us to propose that the former sample was more heterogeneous, consisting of the Mn IV ‐oxo center and secondary species.…”

Dispersion Forces Drive the Formation of Uranium–Alkane Adducts

“…This is typically achieved by using metal catalysis, which forms an intermediate with the hydrocarbon molecule before allowing it to undergo additional reactions to produce a functionalized molecule. While transition-metal complexes are notably known for being able to achieve such activation reactions, − only a few examples of f-element complexes are reported to date . Recently though, low-valent uranium compounds have emerged as good candidates for C−H and small molecule activation processes. − Even though very little is known about the molecular mechanisms involved, it is expected that metal–alkane adducts are key intermediates or intermediate states in activation processes, especially during the bond cleavage event.…”

Hydrogen-atom and oxygen-atom transfer reactivities of iron(iv)-oxo complexes of quinoline-substituted pentadentate ligands

“…7, vide supra). Given the relatively small BDE of the substrate, we posit that this reflects a tipping point where sterics become more important than electronics; as we have pointed out, 16,34 and as is confirmed by the crystal structures of 7 and [Fe IV (O)(N2Py2B)] 2+ , 10 the N2Py2B ligand is less sterically hindering than L2-Qn.…”

“…influence the relative reactivities of their iron(IV)-oxo and manganese(IV)-oxo systems quite differently. 34 While the tilt angle of the iron(IV)vO unit is a consequence of the steric influence of the various ligand substituents in the N4Py framework, and thus modulates the ligand field by virtue of affecting Fe-N distances, 10,15 it is clearly not the only factor that guides the reactivity of the iron(IV)-oxo species. In Fig.…”