Reinholdt Anders, Vibenholt Johan E, Morsing Thorbjørn J, Schau-Magnussen Magnus, Reeler Nini E A, Bendix Jesper
Department of Chemistry , University of Copenhagen , Universitetsparken 5 , DK-2100 , Denmark . Email:
Chem Sci. 2015 Oct 1;6(10):5815-5823. doi: 10.1039/c5sc02077h. Epub 2015 Jul 7.
The π-accepting character of a terminal carbide complex acting as a ligand is demonstrated experimentally and corroborates earlier theoretical predictions. As a result, coordination of a terminal ruthenium carbide complex to electron-rich metal centres is shown to provide a facile and versatile route to carbide-bridged heterometallic complexes. Synthesis, reactivity, spectroscopic and structural characterization are reported for heterobimetallic systems with auxiliary metals from groups : Rh(i), Ir(i), Pd(ii), Pt(ii), Ag(i), and Au(i) coordinated by [Ru(C)Cl(PCy)] (). This encompasses the first example of a homoleptic carbide-ligated transition metal complex: [{(CyP)ClRuC}Au]. Kinetics of substitution on Pt(ii) by ranks the carbide complex as having intermediate nucleophilicity. The C-NMR signals from the carbide ligands are significantly more shielded in the bridged heterobimetallic complexes than in the parent terminal carbide complex. Structurally, forms very shorts bonds to the heterometals, which supports the notion of the multiple bonded complex acting as a π-backbonding ligand. Reactions are reported where displaces CO coordinated to Rh(i) and Ir(i). A strong influence exerted by indicates it to be a stronger σ-donor than CO. The geometries around the carbide bridges resemble those in complexes of electron-rich metals with carbonyl or bridging nitride-complex-derived ligands, which establishes a link to other strong π-acceptor ligands.
作为配体的末端碳化物配合物的π-接受特性通过实验得到证实，并证实了早期的理论预测。结果表明，末端钌碳化物配合物与富电子金属中心的配位为制备碳化物桥连的异金属配合物提供了一种简便且通用的途径。报道了由[Ru(C)Cl(PCy)]（）配位的含第 族辅助金属（Rh(i)、Ir(i)、Pd(ii)、Pt(ii)、Ag(i)和Au(i)）的异双金属体系的合成、反应性、光谱和结构表征。这包括首例全同配位碳化物配体的过渡金属配合物：[{(CyP)ClRuC}Au]。用 对Pt(ii)进行取代反应的动力学将碳化物配合物的亲核性列为中等。在桥连异双金属配合物中，来自碳化物配体的C-NMR信号比在母体末端碳化物配合物中屏蔽得多。在结构上， 与异金属形成非常短的键，这支持了多重键合配合物作为π-反馈键合配体的观点。报道了 取代与Rh(i)和Ir(i)配位的CO的反应。 施加的强烈 影响表明它是比CO更强的σ-供体。碳化物桥周围的几何形状类似于富电子金属与羰基或桥连氮化物配合物衍生配体的配合物中的几何形状，这建立了与其他强π-受体配体的联系。
