Exploring the Limits of Dative Boratrane Bonding: Iron as a Strong Lewis Base in Low-Valent Non-Heme Iron-Nitrosyl Complexes.
Exploring the Limits of Dative Boratrane Bonding: Iron as a Strong Lewis Base in Low-Valent Non-Heme Iron-Nitrosyl Complexes.
复制标题
DOI：
10.1021/acs.inorgchem.0c01686
复制
发表时间：
2020-10-19
影响因子：
4.6
通讯作者：
Lehnert N
中科院分区：
文献类型：
--
作者：
Dong HT;Chalkley MJ;Oyala PH;Zhao J;Alp EE;Hu MY;Peters JC;Lehnert N
我们之前报道了一系列独特的低自旋（ls）{FeNO}8 - 10配合物的合成和初步表征，这些配合物由两亲性三磷硼烷配体[Fe（TPB）（NO）]+/0/-支撑。在此，我们使用先进的光谱技术和密度泛函理论（DFT）计算来提取有关氧化还原系列中键合如何变化的详细信息。我们发现，尽管这些配合物的高度还原性，它们的特点是NO+配体与强Fe-NO π-backbonding和基本上封闭的壳层电子结构的FeNO单元。这是通过整个系列中存在的Fe-B相互作用实现的。特别是还原度最高的[Fe（TPB）（NO）]−络合物，是ls-{FeNO}物种的一个例子，具有真正的反向配位Fe→B键，其中Fe中心充当强路易斯碱。因此，该复合物实际上在电子上类似于ls-{FeNO}系统，其中两个额外的电子“存储”在Fe-B单键中的位置上。该系列中的异常值是ls-{FeNO}复合物，这是由于自旋极化（通过脉冲EPR光谱定量），其削弱了Fe-NO键。通过与相关的N2络合物[Fe（TPB）（N2）]−进行比较，这些数据被进一步上下文化，[Fe（TPB）（N2）] −是Fe（TPB）催化的N2固定的关键中间体。我们目前的研究发现，Fe→B的相互作用是关键的存储所需的电子，以实现在这些系统中的高度还原状态，并强调了陷阱与使用几何参数，试图评估反向配位相互作用，一个发现具有更广泛的影响过渡金属配合物的研究与硼氮杂三环和相关配体。我们使用先进的光谱方法和DFT计算来询问我们独特的氧化还原系列[Fe（TPB）（NO）]+/0/−复合物的电子结构。我们发现，Fe→B相互作用是关键的存储所需的电子，以实现在这些系统中的高度还原状态。进一步比较了相关的N2络合物[Fe（TPB）（N2）]−，它是Fe（TPB）催化的N2固定的关键中间体。
We previously reported the synthesis and preliminary characterization of a unique series of low-spin (ls) {FeNO}8−10 complexes supported by an ambiphilic trisphosphineborane ligand, [Fe(TPB)(NO)]+/0/−. Herein, we use advanced spectroscopic techniques and density functional theory (DFT) calculations to extract detailed information as to how the bonding changes across the redox series. We find that, despite the highly reduced nature of these complexes, they feature an NO+ ligand throughout with strong Fe-NO π-backbonding and essentially closed-shell electronic structures of their FeNO units. This is enabled by an Fe-B interaction that is present throughout the series. In particular, the most reduced [Fe(TPB)(NO)]− complex, an example of a ls-{FeNO} species, features a true reverse dative Fe→B bond where the Fe center acts as a strong Lewis-base. Hence, this complex is in fact electronically similar to the ls-{FeNO} system, with two additional electrons “stored” on site in an Fe-B single bond. The outlier in this series is the ls-{FeNO} complex, due to spin polarization (quantified by pulse EPR spectroscopy), which weakens the Fe-NO bond. These data are further contextualized by comparison with a related N2 complex, [Fe(TPB)(N2)]−, which is a key intermediate in Fe(TPB)-catalyzed N2 fixation. Our present study finds that the Fe→B interaction is key for storing the electrons needed to achieve a highly reduced state in these systems, and highlights the pitfalls associated with using geometric parameters to try to evaluate reverse dative interactions, a finding with broader implications to the study of transition metal complexes with boratrane and related ligands. We use advanced spectroscopic methods and DFT calculations to interrogate the electronic structure of our unique redox series of [Fe(TPB)(NO)]+/0/− complexes. We find that the Fe→B interaction is key for storing the electrons needed to achieve a highly reduced state in these systems. Comparison is further made to the related N2 complex, [Fe(TPB)(N2)]−, which is a key intermediate in Fe(TPB)-catalyzed N2 fixation.
登录
查看更多内容
影响因子：
15
作者：
Confer AM;McQuilken AC;Matsumura H;Moënne-Loccoz P;Goldberg DP
通讯作者：
Goldberg DP
影响因子：
62.1
作者：
Hoffman, Brian M.;Lukoyanov, Dmitriy;Yang, Zhi-Yong;Dean, Dennis R.;Seefeldt, Lance C.
通讯作者：
Seefeldt, Lance C.
影响因子：
4
作者：
Fujisawa, Kiyoshi;Soma, Shoko;Lehnert, Nicolai
通讯作者：
Lehnert, Nicolai
影响因子：
4
作者：
Braunschweig, Holger;Dewhurst, Rian D.
通讯作者：
Dewhurst, Rian D.
影响因子：
4.6
作者：
Burkhardt, Lukas;Vukadinovic, Yannik;Bauer, Matthias
通讯作者：
Bauer, Matthias