Ultrashort metal-metal distances and extreme bond orders

超短金属-金属距离和极端键阶

• 批准号: 172225015
• 负责人: Professor Dr. Rhett Kempe
• 金额: --
• 依托单位: Arbeitsgruppe Anorganische Chemie II
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/172225015?language=en
• 关键词: Ultrashort; metal; distances; extreme; bond; Ultrashort; metal; distances; extreme; bond

Three aspects have been investigated during the first period of support.1. The reactivity of Cr-Cr quintuple bondsStable molecules that contain extremely high bond orders (bond orders > 4) were found only recently. Thus, it is now possible to investigate their reactivity and by doing so we are enabled to understand such bonds better. Our contributions dominate the state of the art in the field of Cr-Cr quintuple bond reactivity worldwide.2. Ultra-short metal-metal distancesRecently, after 30 years of silence new records in terms of short metal-metal distances were obtained with chromium complexes having a formal quintuple bond. Rational ligand design is the key. Work carried our by us determines the state of the art in that field. During the first period of support, we could isolate a compound with a metal-metal distance similar to that of the longest C-C bond (1.706 and 1.704 Å, respectively).3. Bond orders > 4 for molybdenum and tungstenMolybdenum and tungsten complexes are better suited to form high (effective) bond orders. Accordingly, we aimed for transferring the chromium chemistry towards molybdenum and eventually towards tungsten. The state of the art for molybdenum is meanwhile determined by the Tsai group. Tungsten compounds are unknown. We could find an access to such compounds in the first period of support.The following aims have been defined for the second period of researchA. Finalization of the quintuple bond reactivity studiesB. Investigation of the reactivity of the primary activation productsMany products obtained by reacting substrates (or elements) with Cr-Cr quintuple bonds are themselves rather reactive organometallic compounds. Their reactivity especially in catalytic reactions is proposed to be investigated.C. Tungsten complexes with quintuple or sixtuple bondsTungsten complexes having bond orders > 4 are subject of the second period of support. Theoretical work on the instable M2 molecules (M = Cr, Mo and W), species that could only be isolated in an inert matrix, gave effective bond orders of six for Mo2 and W2. Cr2 is characterized by a strong size mismatch of the relevant s- and d-orbitals. Thus, only weakly binding interactions are partially possible. They lead to a low effective bond order. We plan to find an access to W complexes having quintuple (and/or sixtuple) bonds.D. Investigations of the reactivity of tungsten compounds having unusual high bond orders

在支持的第一阶段，已经研究了三个方面1。直到最近才发现含有极高键键（键顺序> 4）的CR-CR五重键键键键键的反应性。这是现在可以调查其反应性的，因此我们可以更好地理解这种纽带。我们的贡献在全球范围内CR-CR Quintuple Bond反应性领域中占主导地位。2。最近，在30年的沉默后，用具有正式的五重键键的铬配合物获得了超短金属金属距离。理性配体设计是关键。我们带来的工作决定了该领域的艺术状况。在支撑的第一阶段，我们可以分离具有类似于最长C-C键（分别为1.706和1.704Å的）金属距离的化合物。3。钼和钨瘤和钨络合物的键订单> 4更适合形成高（有效）粘结顺序。根据，我们旨在将铬化学转移到钼，并最终向钨传递。钼的最新技术是平均的，而由蔡组确定。钨化合物未知。我们可以在第一阶段的第一阶段找到获得此类化合物的途径。在第二阶段的研究中定义了以下目标。五重奏键反应性研究的最终确定。研究通过与CR-CR五重键键反应底物（或元素）获得的主要活化产物的反应性本身是反应性的有机化合物。提议研究它们的反应性，尤其是在催化反应中进行研究。具有五重奏或六块邦德斯坦复合物的钨络合物> 4> 4是第二阶段的支持。关于只能在惰性基质中分离的物种，对稳定的M2分子（M = Cr，MO和W）的理论工作给出了MO2和W2的6个有效键顺序。 CR2的特征是相关的S-和D轨道的强大不匹配。这是部分可能的弱结合相互作用。它们导致较低的有效债券订单。我们计划找到具有五重奏（和/或六个债券）债券的W复合物的访问权限。研究具有异常高键顺序的钨化合物的反应性