Angeles Alvarez M, Esther García M, García-Vivó Daniel, Ruiz Miguel A, Toyos Adrián
Departamento de Química Orgánica e Inorgánica/IUQOEM, Universidad de Oviedo, E-33071 Oviedo, Spain.
Dalton Trans. 2017 Nov 14;46(44):15317-15329. doi: 10.1039/c7dt03580b.
The title complex reacted with [Fe(CO)] to give the trinuclear derivative [FeWCp(μ-H)(μ-PPh)(CO)(NO)] (W-W = 3.044(1) Å) as a result of full insertion of the 16-electron Fe(CO) fragment into the tricentric W-H-W bond of the parent substrate. In contrast, the reactions with the THF adducts [M(CO)(THF)] (M = W, Mo) and [MnCp'(CO)(THF)] (Cp' = CHMe) yielded the μ-hydride derivatives [MWCp(μ-H)(μ-PPh)(CO)(NO)] (W-W = 3.006(1) to 3.164(1) Å for the W compound) and [MnWCpCp'(μ-H)(μ-PPh)(CO)(NO)] respectively, all of them resulting from addition (rather than insertion) of the corresponding 16-electron fragment to the WH moiety of the parent compound. Density Functional Theory calculations revealed that edge- and face-bridged hydride clusters were of similar energy in the WFe system, while the face-bridged structure was significantly more stable (by more than ca. 40 kJ mol) for the W system. Both clusters displayed fast rearrangement in solution involving a flapping movement of the puckered PWM core of these molecules. This was combined, in the WFe cluster, with fast exchange between the almost isoenergetic edge- and face-bridged hydride isomers. The reactions of the title compound with several carbonyl dimers were also examined as an additional synthetic approach to the rational synthesis of heterometallic clusters, but were unsuccessful except in the case of [Co(CO)], which reacted at 253 K in the dark to give a mixture of the binuclear complex [CoWCp(μ-PPh)(CO)(NO)] (Co-W = 2.8623(6) Å) and the trinuclear cluster [CoWCp(μ-PPh)(CO)(NO)] (W-W = 3.1654(4) Å; W-Co = 2.638(1), 2.829(1) Å), the latter resulting from formal replacement of the hydride ligand with the 17-electron fragment Co(CO), which displayed an asymmetric binding to the W centre.
标题配合物与[Fe(CO)]反应，由于16电子的Fe(CO)片段完全插入母体底物的三中心W-H-W键中，生成了三核衍生物[FeWCp(μ-H)(μ-PPh)(CO)(NO)]（W-W = 3.044(1) Å）。相比之下，与四氢呋喃加合物[M(CO)(THF)]（M = W、Mo）和[MnCp'(CO)(THF)]（Cp' = CHMe）的反应分别生成了μ-氢化物衍生物[MWCp(μ-H)(μ-PPh)(CO)(NO)]（对于W化合物，W-W = 3.006(1)至3.164(1) Å）和[MnWCpCp'(μ-H)(μ-PPh)(CO)(NO)]，所有这些都是由相应的16电子片段加到母体化合物的WH部分（而非插入）而产生的。密度泛函理论计算表明，在WFe体系中，边桥和面桥氢化物簇具有相似的能量，而对于W体系，面桥结构明显更稳定（比边桥结构稳定约40 kJ/mol以上）。这两种簇在溶液中都表现出快速重排，涉及这些分子褶皱的PWM核心的摆动运动。在WFe簇中，这与几乎等能量的边桥和面桥氢化物异构体之间的快速交换相结合。还研究了标题化合物与几种羰基二聚体的反应，作为合理合成异金属簇的另一种合成方法，但除了[Co(CO)]的情况外均未成功，[Co(CO)]在253 K黑暗中反应，生成双核配合物[CoWCp(μ-PPh)(CO)(NO)]（Co-W = 2.8623(6) Å）和三核簇[CoWCp(μ-PPh)(CO)(NO)]（W-W = 3.1654(4) Å；W-Co = 2.638(1)，2.829(1) Å）的混合物，后者是由氢化物配体被17电子片段Co(CO)正式取代而产生的，Co(CO)与W中心表现出不对称结合。
