The reaction of 4 equiv. of Li(NC(^tBu)Ph) with Fe^IICl₂ results in isolation of [Li(Et₂O)]₂[Fe^II(NC(^tBu)Ph)₄] (1), in good yields. The reaction of 1 with 1 equiv. of I₂ leads to formation of [Fe^IV(NC(^tBu)Ph)₄] (2), in moderate yields. ⁵⁷Fe Mössbauer spectroscopy confirms the Fe(IV) oxidation state of 2, and X-ray crystallography reveals that 2 has a square planar coordination geometry along with several intramolecular H⋯C interactions. Furthermore, SQUID magnetometry indicates a small magnetic moment at room temperature, suggestive of an accessible S = 1 state. Both density functional theory and multiconfigurational calculations were done to elucidate the nature of the ground state. Consistent with the experimental results, the ground state was found to be an S = 0 state with an S = 1 excited state close in energy.

中文翻译：

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具有低位激发态的同源 Fe（IV） 酮类络合物


4 当量的 Li（N C（^tBu）Ph）） 与 Fe^IICl₂ 反应导致分离出 [Li（Et₂O）_]2[Fe^II（N C（^tBu）Ph）₄] （1），收率良好。1 与 1 当量的 I₂ 反应导致形成 [Fe^IV（N C（^tBu）Ph）₄] （2），产率适中。⁵⁷ 元Fe Mössbauer 光谱证实了 Fe（IV）2 的氧化态，X 射线晶体学显示 2 具有方形平面配位几何形状以及几种分子内 H⋯C 相互作用。此外，SQUID 磁力计表示室温下的磁矩很小，表明 S = 1 状态可达。密度泛函理论和多构型计算都被用来阐明基态的性质。与实验结果一致，发现基态是 S = 0 态，其中 S = 1 激发态在能量上接近。