STRUCTURAL CHARACTERIZATION OF THE ACETYLIDE BRIDGE IN DINUCLEAR (MU-C-EQUIVALENT-TO-CSIME3)-AL/AL AND (MU-C-EQUIVALENT-TO-CSIME3)-AL/ZR COMPLEXES
STRUCTURAL CHARACTERIZATION OF THE ACETYLIDE BRIDGE IN DINUCLEAR (MU-C-EQUIVALENT-TO-CSIME3)-AL/AL AND (MU-C-EQUIVALENT-TO-CSIME3)-AL/ZR COMPLEXES
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DOI：
10.1021/om00036a043
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发表时间：
1993-12-01
期刊：
影响因子：
2.8
通讯作者：
WERNER, S
中科院分区：
文献类型：
--
作者：
ERKER, G;ALBRECHT, M;WERNER, S
两个罕见的例子，含有乙炔配体桥接主族金属（铝）和过渡金属（锆）的配合物进行了描述。这样的络合物通过用2摩尔当量的（炔基）二甲基铝[（RC=C）AlMe 2]2（R = -SiMe 3、-环己基、-CMe 3、-CH 3; 2a-d）处理二甲基二茂锆来制备。在该反应中，可能原位形成（η 2-炔基）二茂锆络合物，其然后被过量的（炔基）二甲基铝捕获以产生络合物Cp 2 Zr（μ-η 1：η 2-RCCMe）（μ-C = CR）AlMe 2（6a-d）。通过X射线衍射对配合物6a（R = SiMe 3）和6 b（R =环己基）进行了表征。为了比较，我们还进行了[（三甲基硅基）乙炔基]二甲基铝二聚体2a的X射线晶体结构分析。配合物6含有一个双金属双环骨架。其中一个桥头位置是平面四配位的碳中心。在这些配合物中，锆和铝之间的-C = CR桥可以被描述为主要是mu-（σ-乙炔化物）特征。
Two rare examples of complexes that contain an acetylide ligand bridging between a main group metal (aluminum) and a transition metal (zirconium) are described. Such complexes are prepared by treatment of dimethylzirconocene with 2 molar equiv of (alkynyl)dimethylaluminum [(RC=C)AlMe2]2 (R = -SiMe3, -cyclohexyl, -CMe3, -CH3; 2a-d). In this reaction an (eta2-alkyne)zirconocene complex is probably formed in situ which is then trapped by the excess (alkynyl)dimethylaluminum to yield the complexes Cp2Zr(mu-eta1:eta2-RCCMe)(mu-C = CR)AlMe2 (6a-d). The complexes 6a (R = SiMe3) and 6b (R = cyclohexyl) were characterized by X-ray diffraction. For comparison, we have also carried out the X-ray crystal structure analysis of the [(trimethylsilyl)ethynyl]dimethylaluminum dimer 2a. The complexes 6 contain a dimetallabicyclic framework. One of the bridgehead positions is a carbon center which is planar-tetracoordinate. In these complexes the -C = CR bridge between zirconium and aluminum can be described as being mainly of mu-(sigma-acetylide) character.