Enhanced Fe-Centered Redox Flexibility in Fe–Ti Heterobimetallic Complexes
Enhanced Fe-Centered Redox Flexibility in Fe–Ti Heterobimetallic Complexes
复制标题
DOI：
10.1021/acs.inorgchem.9b00442
复制
发表时间：
2019-04
影响因子：
4.6
通讯作者：
James T Moore;S. Chatterjee;Maxime Tarrago;Laura J. Clouston;Stephen Sproules;E. Bill;Varinia Bernales;L. Gagliardi;Shengfa Ye;K. Lancaster;Connie C. Lu
中科院分区：
文献类型：
--
作者：
James T Moore;S. Chatterjee;Maxime Tarrago;Laura J. Clouston;Stephen Sproules;E. Bill;Varinia Bernales;L. Gagliardi;Shengfa Ye;K. Lancaster;Connie C. Lu
在此之前，我们报道了Ti[N（o-（NCH_2 P（iPr）_2）C_6 H_4）_3]和Fe-Ti配合物FeTi[N（o-（NCH_2 P（iPr）_2）C_6 H_4）_3]的合成，分别简称为TiL（1）和FeTiL（2）。在此，我们描述了完整的氧化还原家族的monostratios Ti和Fe-Ti化合物的合成和表征。FeTiL的循环伏安法研究表明，还原和氧化过程分别在−2.16和−1.36 V（相对于Fc/Fc+）。两个同构的氧化还原成员，[FeTiL]+和[FeTiL]−（分别为2 ox和2 red），沿着BrFeTiL（2-Br）和单金属[TiL]+配合物（1 ox）被合成和表征。[FeTiL]+/0/-系列的固态结构特征在于短的金属-金属键，范围为1.94-2.38 μ m，其全部短于Ti和Fe单键金属半径的总和（参见图1）。2.49）。为了阐明键合和电子结构，配合物的特征在于与一系列光谱方法，包括NMR，EPR，和57 Fe穆斯堡尔，以及Ti和Fe K边X射线吸收光谱（XAS）。这些研究，沿着与混合密度泛函理论（DFT）和含时DFT计算，表明在同构[FeTiL]+，0，-系列的氧化还原过程主要是铁为基础的，极化Fe-Ti π-键发挥作用，在离域的一些额外的电子密度从Fe到Ti（净13%）。
Previously, we reported the synthesis of Ti[N(o-(NCH2P(iPr)2)C6H4)3] and the Fe–Ti complex, FeTi[N(o-(NCH2P(iPr)2)C6H4)3], abbreviated as TiL (1), and FeTiL (2), respectively. Herein, we describe the synthesis and characterization of the complete redox families of the monometallic Ti and Fe–Ti compounds. Cyclic voltammetry studies on FeTiL reveal both reduction and oxidation processes at −2.16 and −1.36 V (versus Fc/Fc+), respectively. Two isostructural redox members, [FeTiL]+ and [FeTiL]− (2ox and 2red, respectively) were synthesized and characterized, along with BrFeTiL (2-Br) and the monometallic [TiL]+ complex (1ox). The solid-state structures of the [FeTiL]+/0/– series feature short metal–metal bonds, ranging from 1.94–2.38 Å, which are all shorter than the sum of the Ti and Fe single-bond metallic radii (cf. 2.49 Å). To elucidate the bonding and electronic structures, the complexes were characterized with a host of spectroscopic methods, including NMR, EPR, and 57Fe Mössbauer, as well as Ti and Fe K-edge X-ray absorption spectroscopy (XAS). These studies, along with hybrid density functional theory (DFT) and time-dependent DFT calculations, suggest that the redox processes in the isostructural [FeTiL]+,0,– series are primarily Fe-based and that the polarized Fe–Ti π-bonds play a role in delocalizing some of the additional electron density from Fe to Ti (net 13%).