A series of iron complexes featuring the pyridine dipyrrolide (PDP) pincer ligand [^Cl2PhPDP^Ph]²⁻, obtained via deprotonation of 2,6-bis(5-(2,6-dichlorophenyl)-3-phenyl-1H-pyrrol-2-yl)pyridine, H₂^Cl2PhPDP^Ph, is reported and structurally and spectroscopically characterized. While the bis-pyridine adduct (^Cl2PhPDP^Ph)Fe(py)₂ exhibits nearly identical features as previously reported (^MesPDP^Ph)Fe(py)₂ (H₂^MesPDP^Ph=2,6-bis(5-(2,4,6-trimethylphenyl)-3-phenyl-1H-pyrrol-2-yl)pyridine), the diethyl ether and tetrahydrofuran adducts (^Cl2PhPDP^Ph)Fe(OEt₂) and (^Cl2PhPDP^Ph)Fe(thf) show additional weak Fe−Cl interactions that impact the overall coordination geometries and result in strong deviations from planar coordination environments. The reaction of (^Cl2PhPDP^Ph)Fe(thf) with 1-adamantyl azide provided the isolable iron imido complex (^Cl2PhPDP^Ph)Fe(N¹Ad), highlighting the improved stability of [^Cl2PhPDP^Ph]²⁻ towards intramolecular nitrene group transfer from the high-valent iron-imido unit. The electronic structure of (^Cl2PhPDP^Ph)Fe(N¹Ad) was investigated by density functional theory (DFT) and complete active space self-consistent field (CASSCF) calculations. These computational studies suggest energetically close-lying diamagnetic and paramagnetic states and help to conceptualize the unusual magnetic properties of the complex observed by variable-temperature ¹H NMR spectroscopy.

中文翻译：

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2,6-二氯苯基取代基对吡啶二吡咯铁配合物配位化学的影响

通过 2,6-双(5-(2,6-二氯苯基)-3-苯基-1 H-吡咯的去质子化获得的一系列具有吡啶二吡咯烷 (PDP) 钳状配体 [ ^Cl2Ph PDP ^Ph ] ²⁻的铁配合物-2-基)吡啶，H ₂ ^Cl2Ph PDP ^Ph被报道并在结构和光谱上表征。虽然双吡啶加合物 ( ^Cl2Ph PDP ^Ph )Fe(py) ₂表现出与先前报道的几乎相同的特征 ( ^Mes PDP ^Ph )Fe(py) ₂ (H ₂ ^Mes PDP ^Ph =2,6-bis(5-(2 ,4,6-三甲基苯基)-3-苯基-1H -pyrrol-2-yl)pyridine)、乙醚和四氢呋喃加合物 ( ^Cl2Ph PDP ^Ph )Fe(OEt ₂ ) 和 ( ^Cl2Ph PDP ^Ph )Fe(thf) 表现出额外的弱 Fe-Cl 相互作用，影响整体配位几何并导致与平面协调环境的强烈偏差。( ^Cl2Ph PDP ^Ph )Fe(thf) 与 1-金刚烷基叠氮化物的反应提供了可分离的亚胺铁配合物 ( ^Cl2Ph PDP ^Ph )Fe(N ¹ Ad)，突出了 [ ^Cl2Ph PDP ^Ph ] ²⁻稳定性的提高从高价铁-亚氨基单元向分子内氮烯基转移。通过密度泛函理论（DFT）和完全活性空间自洽场（CASSCF）计算研究了（^Cl2Ph PDP ^Ph）Fe（N ¹ Ad）的电子结构。这些计算研究表明，在能量上存在紧密的反磁性和顺磁性状态，并有助于将变温¹ H NMR 光谱观察到的复合物的异常磁性概念化。