494843-67-3Relevant academic research and scientific papers
Heterolytic H2 activation mediated by low-coordinate L 3Fe-(μ-N)-FeL3 complexes to generate Fe(μ-NH)(μ-H)Fe species
Brown, Steven D.,Mehn, Mark P.,Peters, Jonas C.
, p. 13146 - 13147 (2005)
The diiron μ-nitride complexes, {L3FeII(μ-N)FeIIL3}- and L3FeIII(μ-N)FeIIL3, heterolytically activate hydrogen (1 atm) at ambient temperature in solution (L3 = [PhB(CH2PPh2)3]-). These transformations lead to structurally unique {L3FeII(μ-NH)(μ-H)FeIIL3}- and L3FeIII(μ-NH)(μ-H)FeIIL3 products. X-ray data establish a marked reduction in the Fe-Fe distance upon H2 uptake, and spectroscopic data establish both FeIIFeII species to be diamagnetic, whereas the FeIIIFeII species, L3FeIII(μ-N)FeIIL3 and L3FeIII(μ-NH)(μ-H)FeIIL3, populate doublet ground states with thermally accessible higher spin states. Copyright
A low-spin d5 iron imide: Nitrene capture by low-coordinate iron(I) provides the 4-coordinate Fe(III) complex [PhB(CH2PPh2)3]Fe≡N-p-tolyl
Brown, Steven D.,Betley, Theodore A.,Peters, Jonas C.
, p. 322 - 323 (2003)
Entry into [PhBP3]Fe chemistry affords a rare, pseudotetrahedral iron(I) complex, [PhBP3]Fe(PPh3), with an S = 3/2 ground state. This precursor undergoes rapid oxidation by aryl azide to produce the d5 imide [PhBP3]FeNAr (Ar=p-tolyl). The Fe (III) imide is significant in that it is low-spin and represents the first mononuclear imide of iron. Doublet [PhBP 3]FeN≡Ar reacts rapidly and quantitatively with CO at room temperature to release isocyanate and [PhBP3] Fe(CO)2. The [PhBP3]Fe(CO)2 byproduct is also precursor to [PhBP3]FeN≡Ar upon addition of aryl azide. Copyright
CO2 reduction by Fe(i): Solvent control of C-O cleavage versus C-C coupling
Saouma, Caroline T.,Lu, Connie C.,Peters, Jonas C.
, p. 4042 - 4051 (2013/09/23)
This manuscript explores the product distribution of the reaction of carbon dioxide with reactive iron(i) complexes supported by tris(phosphino)borate ligands, [PhBPR3]- ([PhBPR3]- = [PhB(CH2PR 2)3]-; R = CH2Cy, Ph, iPr, mter; mter = 3,5-meta-terphenyl). Our studies reveal an interesting and unexpected role for the solvent medium with respect to the course of the CO2 activation reaction. For instance, exposure of methylcyclohexane (MeCy) solutions of to CO2 yields the partial decarbonylation product. When the reaction is instead carried out in benzene or THF, reductive coupling of CO2 occurs to give the bridging oxalate species. Reaction studies aimed at understanding this solvent effect are presented, and suggest that the product profile is ultimately determined by the ability of the solvent to coordinate the iron center. When more sterically encumbering auxiliary ligands are employed to support the iron(i) center (i.e., [PhBPPh3]- and [PhBPiPr3]-), complete decarbonylation is observed to afford structurally unusual diiron(ii) products of the type {[PhBPR3]Fe}2(μ-O). A mechanistic hypothesis that is consistent with the collection of results described is offered, and suggests that reductive coupling of CO2 likely occurs from an electronically saturated FeII-CO2- species.
Ground-state singlet L3Fe-(μ-N)-FeL3 and L 3Fe(NR) complexes featuring pseudotetrahedral Fe(II) centers
Brown, Steven D.,Peters, Jonas C.
, p. 1913 - 1923 (2007/10/03)
Pseudotetrahedral iron(II) coordination complexes that contain bridged nitride and terminal imide linkages, and exhibit singlet ground-state electronic configurations, are described. Sodium amalgam reduction of the ferromagnetically coupled dimer, {[PhBP3]Fe(μ-1,3-N 3)}2 (2) ([PhBP3] = [PhB(CH2PPh 2)3]-), yields the diamagnetic bridging nitride species [{[PhBP3]Fe}2(μ-N)][Na(THF)5] (3). The Fe-N-Fe linkage featured in the anion of 3 exhibits an unusually bent angle of approximately 135°, and the short Fe-N bond distances (Fe-Nav ≈ 1.70 A) suggest substantial Fe-N multiple bond character. The diamagnetic imide complex {[PhBP3]Fe∥≡N(1-Ad)} {nBu4N} (4) has been prepared by sodium amalgam reduction of its low-spin iron(III) precursor, [PhBP3]FeIII≡N(1-Ad) (5). Complexes 4 and 5 have been structurally characterized, and their respective electronic structures are discussed in the context of a supporting DFT calculation. Diamagnetic 4 provides a bona fide example of a pseudotetrahedral iron(II) center in a low-spin ground-state configuration. Comparative optical data strongly suggest that dinuclear 3 is best described as containing two high-spin iron(II) centers that are strongly antiferromagnetically coupled to give rise to a singlet ground-state at room temperature.
