Elusive Trimethyllanthanum: Snapshots of Extensive Methyl Group Degradation in La-Al Heterobimetallic Complexes
Elusive Trimethyllanthanum: Snapshots of Extensive Methyl Group Degradation in La-Al Heterobimetallic Complexes
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DOI：
10.1002/chem.200801174
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发表时间：
2008-01-01
影响因子：
4.3
通讯作者：
Anwander, Reiner
中科院分区：
文献类型：
--
作者：
Gerber, Laura C. H.;Le Roux, Erwan;Anwander, Reiner
[La(AlMe4)(3)]和[Y(AlMe4)(3)]与PMe3的反应表明膦可以裂解Ln-CH3-Al键，分离出Me3Al(PMe3)。 PMe3（3摩尔当量）与[Y(AlMe4)(3)]反应生成被含有磷和铝的副产物污染的[(YMe3)(n)]。 La基类似物。 [(LaMe3)(n)]在[La(AlMe4)(3)]与PMe3或Et2O反应之前不会选择性地形成，而是产生不溶性的La/Al异双金属产物。通过[La(AlMe4)(3)]与PMe3（1当量）的反应获得了三个多核La基团簇，并通过X射线结构分析进行了鉴定。每个簇都表现出广泛的甲基降解并包含亚甲基、次甲基或碳化物部分。 [La4Al8(CH)(4)(CH2)(2)(CH3)(20)(PMe3)]具有由AlMe3、Me2AlCH2AlMe2和PMe3配体支撑的{La-4(CH)(4)}长方体核心。 [La4Al8(C)(CH)(2)(CH2)(2)(CH3)(22)-(toluene)]还包含一个长方体核，{La3Al(C)(CH)(2)(CH2)}，其中包含一个外型立方镧原子，并由 AlMe3、Me3AlCH2AlMe2、(AlMe4)(-) 和甲苯配体支撑。 [La5Al9(CH)(6)(CH3)(30)] 中的镧原子以三角双锥体方式排列，每个面均带有 (CH) 官能团。 {La-5(CH)(6)}(3-) 核心由三个 AlMe2+ 部分形式平衡，并另外由六个 AlMe3 配体支持。该晶胞包含两个独立的 La-5 簇，一个具有伪 C-3h 对称性，另一个具有伪 D-3 对称性，以及两个分离副产物 Me3Al(PMe3) 分子。
Reactions of [La(AlMe4)(3)] and [Y(AlMe4)(3)] with PMe3 show that the phosphine can cleave Ln-CH3-Al linkages, separating Me3Al(PMe3). PMe3 (3 mol equiv) reacts with [Y(AlMe4)(3)] to give [(YMe3)(n)] contaminated with by-products containing phosphorus and aluminum. The La-based analog. [(LaMe3)(n)], is not formed selectively front the reaction of [La(AlMe4)(3)] with PMe3, or Et2O, which rather yields insoluble La/Al heterobimetallic products. Three multinuclear La-based clusters were obtained from a reaction of [La(AlMe4)(3)] with PMe3 (1 equiv) and identified by X-ray structure analyses. Each cluster exhibits extensive methyl group degradation and contains methylene, methine, or carbide moieties. [La4Al8(CH)(4)(CH2)(2)(CH3)(20)(PMe3)] has a {La-4(CH)(4)} cuboid core supported by AlMe3, Me2AlCH2AlMe2, and PMe3 ligands. [La4Al8(C)(CH)(2)(CH2)(2)(CH3)(22)-(toluene)] also contains a cuboid core, {La3Al(C)(CH)(2)(CH2)}, which includes one exo cubic lanthanum atom, and is supported by AlMe3, Me3AlCH2AlMe2, (AlMe4)(-), and toluene ligands. The lanthanum atoms in [La5Al9(CH)(6)(CH3)(30)] are arranged in a trigonal bipyramidal fashion with (CH) functionalities capping each face. The {La-5(CH)(6)}(3-) core is formally balanced by three AlMe2+ moieties and is additionally supported by six AlMe3 ligands. The unit cell contains two independent La-5 clusters, one with pseudo-C-3h and the other with pseudo-D-3 symmetry, as well as two molecules of the separation co-product Me3Al(PMe3).