More Like this

1. 10 ⁶ -fold faster C–H bond hydroxylation by a Co ^III,IV ₂ (µ-O) ₂ complex [via a Co ^III ₂ (µ-O)(µ-OH) intermediate] versus its Fe ^III Fe ^IV analog

   https://doi.org/10.1073/pnas.2307950120  

   Li, Yan; Abelson, Chase; Que, Lawrence; Wang, Dong (December 2023, Proceedings of the National Academy of Sciences)

   The hydroxylation of C–H bonds can be carried out by the high-valent Co^III,IV₂(µ-O)₂complex2asupported by the tetradentate tris(2-pyridylmethyl)amine ligand via a Co^III₂(µ-O)(µ-OH) intermediate (3a). Complex3acan be independently generated either by H-atom transfer (HAT) in the reaction of2awith phenols as the H-atom donor or protonation of its conjugate base, the Co^III₂(µ-O)₂complex1a. Resonance Raman spectra of these three complexes reveal oxygen-isotope-sensitive vibrations at 560 to 590 cm⁻¹associated with the symmetric Co–O–Co stretching mode of the Co₂O₂diamond core. Together with a Co•••Co distance of 2.78(2) Å previously identified for1aand2aby Extended X-ray Absorption Fine Structure (EXAFS) analysis, these results provide solid evidence for their “diamond core” structural assignments. The independent generation of3aallows us to investigate HAT reactions of2awith phenols in detail, measure the redox potential and pK_aof the system, and calculate the O–H bond strength (D_O–H) of3ato shed light on the C–H bond activation reactivity of2a. Complex3ais found to be able to transfer its hydroxyl ligand onto the trityl radical to form the hydroxylated product, representing a direct experimental observation of such a reaction by a dinuclear cobalt complex. Surprisingly, reactivity comparisons reveal2ato be 10⁶-fold more reactive in oxidizing hydrocarbon C–H bonds than corresponding Fe^III,IV₂(µ-O)₂and Mn^III,IV₂(µ-O)₂analogs, an unexpected outcome that raises the prospects for using Co^III,IV₂(µ-O)₂species to oxidize alkane C–H bonds. 

   more » « less
2. Fe ₄ Cluster and a Buckled Macrocycle Complex from the Reduction of [(dmgBF ₂ ) ₂ Fe(L) ₂ ] (L = MeCN, ^t Bu ⁱ NC)

   https://doi.org/10.1021/ic202253v  

   Rose, Michael J.; Winkler, Jay R.; Gray, Harry B. (February 2012, Inorganic Chemistry)
3. Structural Motifs of [Fe(CO ₂ ) _n ] ⁻ Clusters ( n = 3–7)

   https://doi.org/10.1021/acs.jpca.7b02742  

   Thompson, Michael C.; Dodson, Leah G.; Weber, J. Mathias (May 2017, The Journal of Physical Chemistry A)
4. Pyrazolylborates and Their Importance in Tuning Single-Molecule Magnet Properties of {Fe ^III ₂ Ni ^II } Complexes

   https://doi.org/10.1021/ic2017825  

   Zhang, Yuan-Zhu; Mallik, Uma P.; Rath, Nigam P.; Clérac, Rodolphe; Holmes, Stephen M. (November 2011, Inorganic Chemistry)
5. First Structurally Characterized Tricyanomanganate(III) and its Magnetic {Mn ^III ₂ M ^II ₂ } Complexes (M ^II = Mn, Ni)

   https://doi.org/10.1021/ic1006605  

   Tang, Minao; Li, Dongfeng; Mallik, Uma Prasad; Withers, Jeffrey R.; Brauer, Shari; Rhodes, Michael R.; Clérac, Rodolphe; Yee, Gordon T.; Whangbo, Myung-Hwan; Holmes, Stephen M. (June 2010, Inorganic Chemistry)