847654-77-7Relevant academic research and scientific papers
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 (2005)
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.
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 (2007/10/03)
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
