Xémard Mathieu, Zimmer Sébastien, Cordier Marie, Goudy Violaine, Ricard Louis, Clavaguéra Carine, Nocton Grégory
LCM, CNRS , Ecole polytechnique, Université Paris-Saclay , Route de Saclay , 91128 Palaiseau cedex, France.
Laboratoire de Chimie Physique , CNRS-Université Paris-Sud, Université Paris-Saclay , 15 avenue Jean Perrin , 91405 Orsay Cedex, France.
J Am Chem Soc. 2018 Oct 31;140(43):14433-14439. doi: 10.1021/jacs.8b09081. Epub 2018 Oct 22.
The Article presents the synthesis, structure, and bonding of a series of neutral and linear sandwich compounds with the cyclononatetraenyl (Cnt) ligand and divalent lanthanides. These compounds account for the emergence of the lanthanidocene series in reference to the ferrocene and uranocene. The synthetic strategy uses the solubility difference between two conformational isomers of the ligand, as well as the isomerization of the compounds induced by solvent coordination, yielding the isomorphous and isostructural neutral and rigorously linear sandwich complexes. The molecular structures feature a Cnt-Ln-Cnt angle of 180° and a ring size close to the Cnt-Cnt(centroid) distance. A qualitative molecular orbital diagram is provided, in D symmetry, and DFT calculations enforce the bonding model.
本文介绍了一系列含有环壬四烯基（Cnt）配体和二价镧系元素的中性线性夹心化合物的合成、结构和键合。参照二茂铁和铀茂，这些化合物解释了镧系茂类化合物系列的出现。合成策略利用了配体两种构象异构体之间的溶解度差异，以及溶剂配位诱导的化合物异构化，从而得到同晶型和同结构的中性且严格线性的夹心配合物。分子结构的特点是Cnt-Ln-Cnt角为180°，且环尺寸接近Cnt-Cnt（质心）距离。提供了一个D对称性的定性分子轨道图，密度泛函理论计算证实了该键合模型。
