The ground state electronic structures of [Fe^IIIX(L^ISQ)₂]⁰ where X is a halide (F⁻, Cl⁻, Br⁻, I⁻) or pseudo‐halide (N₃⁻, NCS⁻) and (LISQ)¹⁻ is the o‐iminobenzosemiquinonato π‐radical ligand, have been calculated using DFT at the B3LYP* level of theory. The modified functional with 15% Hartree‐Fock exchange is required to successfully reproduce the spin ground state of the complex as either S=³/₂ for X=F⁻, Cl⁻ and NCS⁻, or S=¹/₂ for X=Br⁻, I⁻ and N₃⁻. The difference in ground state stems from an S_Fe=⁵/₂→S_Fe=³/₂ spin transition at the iron ion, prompted by the donor properties of the apical ligand. The computational methodology was validated through accurate calculation of the Mössbauer parameters. The redox chemistry of the o‐aminophenolate ligand was examined for the putative five‐membered electron transfer series for [Fe^IIIF(L^ISQ)₂]^z and [Fe^IIII(L^ISQ)₂]^z (z=2+1+, 0, 1−, 2−). The redox chemistry is entirely ligand‐centered with retention of the ferric ion, where only the strong ligand field provided by a fully reduced o‐anilinophenolate(2−) ligand in conjunction with a soft apical donor will support an intermediate‐spin Fe(III) central ion.

中文翻译：

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用自由基配体调节铁的自旋态：密度泛函理论研究

[Fe的基态电子结构^III X（L ^ISQ）₂ ] ⁰，其中X是卤素（F ^{- ，}氯^- ，溴^- ，我^- ）或伪卤化物（N ₃ ^-，NCS ^- ）和（LISQ ）¹⁻是邻氨基亚氨基苯并半醌基的π自由基配体，已在理论上以B3LYP *水平使用DFT计算得出。修改后的，用15％的官能哈特里-福克交换才能成功地再现复杂的自旋基态如任一小号= ³ / ₂为X = F ^- ，氯^-和NCS ^- ，或小号= ¹ / ₂为X为Br ^- ，我^-和N ₃ ^- 。在基态的差异从茎小号_的Fe = ⁵ / ₂ →小号_的Fe = ³ / ₂在铁离子自旋转换，通过心尖配体的供体性质提示。通过精确计算Mössbauer参数验证了计算方法。对[Fe]的假定的五元电子转移系列检查了邻氨基酚酸酯配体的氧化还原化学^III F（L ^ISQ）₂ ] ^z和[Fe ^III I（L ^ISQ）₂ ] ^z（z = 2 + 1 +，0，1-，2-）。所述氧化还原化学完全配体为中心的与三价铁离子，其中只有强配位场被完全还原提供的保留ø -anilinophenolate（2-）配体与软顶端供体将支持的中间自旋铁结合（III ）中心离子。