Hertler Phoebe R, Lewis Richard A, Wu Guang, Hayton Trevor W
Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States.
Inorg Chem. 2023 Jul 31;62(30):11829-11836. doi: 10.1021/acs.inorgchem.3c01109. Epub 2023 Jul 18.
Reaction of Fe(acac) with 3 equiv of Li[N═C(R)Ph] (R = Ph, Bu) results in the formation of the [Fe] complexes, [Fe(μ-N═C(R)Ph)(N═C(R)Ph)] (R = Ph, ; Bu, ), in low to moderate yields. Reaction of FeCl with 6 equiv of Li(N═CH) (HN═CH = 9-fluorenone imine) results in the formation of [Li(THF)][Fe(N═CH)] () in good yield. Subsequent oxidation of with ca. 0.8 equiv of I generates the [Fe] complex, [Fe(μ-N═CH)(N═CH)] (), along with free fluorenyl ketazine. Complexes , , and were characterized by H NMR spectroscopy, X-ray crystallography, Fe Mössbauer spectroscopy, and SQUID magnetometry. The Fe-Fe distances in , , and range from 2.803(7) to 2.925(1) Å, indicating that no direct Fe-Fe interaction is present in these complexes. The Fe Mössbauer spectra for complexes , , and are all consistent with the presence of symmetry-equivalent high-spin Fe centers. Finally, all three complexes exhibit a similar degree of antiferromagnetic coupling between the metal centers ( = -26 to -30 cm), as ascertained by SQUID magnetometry.
Fe(acac)与3当量的Li[N═C(R)Ph]（R = Ph，Bu）反应生成[Fe]配合物[Fe(μ-N═C(R)Ph)(N═C(R)Ph)]（R = Ph， ；Bu， ），产率低至中等。FeCl与6当量的Li(N═CH)（HN═CH = 9-芴酮亚胺）反应，以良好的产率生成[Li(THF)][Fe(N═CH)]（ ）。随后用约0.8当量的I氧化 生成[Fe]配合物[Fe(μ-N═CH)(N═CH)]（ ）以及游离的芴基酮嗪。配合物 、 和 通过1H NMR光谱、X射线晶体学、Fe穆斯堡尔光谱和SQUID磁强计进行了表征。 、 和 中的Fe-Fe距离在2.803(7)至2.925(1) Å范围内，表明这些配合物中不存在直接的Fe-Fe相互作用。配合物 、 和 的Fe穆斯堡尔光谱均与对称等效的高自旋Fe中心的存在一致。最后，通过SQUID磁强计确定，所有三种配合物在金属中心之间都表现出相似程度的反铁磁耦合（J = -26至-30 cm-1）。
