Molecular oxofluorides OMFn of nickel, palladium and platinum: oxyl radicals with moderate ligand field inversion
Molecular oxofluorides OMFn of nickel, palladium and platinum: oxyl radicals with moderate ligand field inversion
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DOI：
10.1039/d0qi01151g
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发表时间：
2021-03-07
影响因子：
7
通讯作者：
Riedel, Sebastian
中科院分区：
文献类型：
--
作者：
Li, Lin;Beckers, Helmut;Riedel, Sebastian
高价后过渡金属的末端含氧化合物因其独特的金属-氧键而引起人们的关注，其中含氧配体表现出亲电的、独特的氧自由基（O中心点-），而不是通常预期的亲核（O-2（-））特征。这些性质赋予后过渡金属含氧化合物在氧化反应以及H-原子转移（HAT）和O-原子转移（OAT）反应中有希望的高反应性。另一方面，由于它们的高反应性，直接的光谱证据，特别是高价镍氧代化合物是罕见的。在这项工作中，我们报告了第10族金属原子M = Ni，Pd和Pt的线性氧代单氟化物OMF（C-oov）和二氟化物OMF 2（C-2 v），以及次氟酸盐FOPdF（C-s）和氧代三氟化物OPtF 3（C-2 v）。这些分子通过金属原子与气态OF 2的反应制备，并在固体Ne和Ar基质中分离。在DFT、CCSD（T）、CASPT 2和MRCI水平上，通过IR基体分离光谱和电子结构计算的联合分析，对它们进行了研究。线性OMF分子具有（4）σ（-）基态并且带有末端氧自由基配体。氧代二氟化物在（3）A（2）电子态下具有平面T形结构。这些二氟化物中的末端氧代配体也具有>= 1.0的大自旋密度。关于最近报道的ONiF 2的电子基态的矛盾[Wei等人，无机化学，2019，58，9796-9810]可以通过观察更完整的振动光谱来实验解决。讨论了第10族过渡金属氟氧化物及其相关化合物中氧代配体上电子和自旋布居的关系。ONiF 2和OCuF 2中的金属-氧键存在显著差异。通过比较第10族（O[10]F）的线性氧代一氟化物与第9族（F[9]F）的二氟化物和第11族（O[11]O）的等电子二氧化物，显示了从主要离子场到反向配体场的连续过渡。
Terminal oxo compounds of high-valent late transition metals attracted attention because of their peculiar metal-oxygen bond in which the oxo ligand exhibits an electrophilic and distinct radical oxyl (O center dot-) rather than the commonly expected nucleophilic (O-2(-)) character. These properties confer the late transition metal oxo compounds their promising high reactivity in oxidation reactions, as well as H-atom transfer (HAT) and O-atom transfer (OAT) reactions. On the other hand, because of their highly reactive nature, direct spectroscopic evidence especially for high-valent nickel oxo compounds is rare. In this work, we report on linear oxo monofluorides OMF (C-oov) and difluorides OMF2 (C-2v) of the group 10 metal atoms M = Ni, Pd and Pt, as well as on the hypofluorite FOPdF (C-s) and the oxo trifluoride OPtF3 (C-2v). These molecules were prepared by the reaction of the metal atoms with gaseous OF2 and isolated in solid Ne and Ar matrices. They have been investigated by a joint analysis of IR matrix isolation spectroscopy and electronic structure calculations at the DFT, CCSD(T), as well as CASPT2 and MRCI levels of theory. The linear OMF molecules have (4)Sigma(-) ground states and bear a terminal oxyl radical ligand. The oxo difluorides have planar T-shaped structures in the (3)A(2) electronic states. The terminal oxo ligand in these difluorides also carries large spin densities of >= 1.0. A contradiction about the electronic ground state for the recently reported ONiF2 [Wei et al., Inorg. Chem., 2019, 58, 9796-9810] could be solved experimentally by the observation of a more complete vibrational spectrum. The relationship between the electron and spin population on the oxo ligand in the group 10 transition metal oxofluorides and related compounds will be discussed. Remarkable differences were found for the metal-oxygen bonds in ONiF2 and OCuF2. The continuous transition from a predominantly ionic to an inverted ligand field is shown by comparing the linear oxo monofluorides of group 10 (O[10]F), with the difluorides of group 9 (F[9]F) and the isoelectronic dioxides of group 11 (O[11]O).