Synthesis and Structure Diversity of Half‐Sandwich Rare Earth Dialkynyl Complexes
Synthesis and Structure Diversity of Half‐Sandwich Rare Earth Dialkynyl Complexes
复制标题
半夹心稀土二炔基配合物的合成及结构多样性
DOI：
10.1002/hlca.202100197
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发表时间：
2021
影响因子：
1.8
通讯作者：
Hou Zhaomin
中科院分区：
文献类型：
--
作者：
Xiong Gang;Tardif Olivier;Nishiura Masayoshi;Bingtao Guan;Hou Zhaomin
半夹心稀土二炔基配合物在结构和反应性方面都很感兴趣，但迄今为止仍有很多研究不足。在这里，我们报告了一个新的家庭的半夹心二炔基配合物的合成和转化轴承C5 Me 4SiMe 3配体，表现出不同的结构特征取决于金属离子的大小，炔取代基和有或没有THF的协调。半夹心稀土二烷基配合物（C5 Me 4SiMe 3）Ln（CH 2SiMe 3）2（THF）（Ln=Sc，Y，Lu）和两当量的末端炔如苯乙炔和三甲基硅基乙炔在THF中的酸碱反应通常得到相应的THF配位的单体稀土二炔基配合物，其在从甲苯中重结晶时产生进一步聚集的炔基配合物，其中THF配体部分或完全解离。在苯乙炔的情况下，形成三聚钇和镥六炔基配合物，其中每对金属原子在固态下由两个炔基配体桥接，但炔基配体在甲苯溶液中进行快速的位置交换。在三甲基硅基乙炔与钇和镥的情况下，从甲苯中得到带有两个末端和两个桥接炔基配体的二聚四炔基配合物。相反，从甲苯中重结晶的钪三甲基甲硅烷基乙炔络合物诱导炔基偶联，并产生二聚钪络合物与一个butatrienediyl和两个炔基桥接配体。在THF中溶解后，由于THF与稀土金属原子的配位，所有聚集的炔基/丁三烯二基络合物迅速再转化为单体二炔基络合物。
Half‐sandwich rare‐earth dialkynyl complexes are of much interest in both structure and reactivity but have remained much underexplored to date. Here we report the synthesis and transformation of a new family of half‐sandwich dialkynyl complexes bearing the C5Me4SiMe3ligand, which exhibited diverse structural features depending on metal ion size, alkyne substituent and with or without THF coordination. The acid‐base reactions between half‐sandwich rare earth dialkyl complexes (C5Me4SiMe3)Ln(CH2SiMe3)2(THF) (Ln=Sc, Y, Lu) and two equivalents of terminal alkynes such as phenylacetylene and trimethylsilylacetylene in THF generally gave the corresponding THF‐coordinated monomeric rare earth dialkynyl complexes, which upon recrystallization from toluene yielded further aggregated alkynyl complexes with partial or full dissociation of the THF ligands. In the case of phenylacetylene, trimeric yttrium and lutetium hexaalkynyl complexes were formed, in which each pair of the metal atoms was bridged by two alkynyl ligands in solid state but the alkynyl ligands underwent rapid site exchange in toluene solution. In the case of trimethylsilylacetylene with yttrium and lutetium, dimeric tetraalkynyl complexes bearing two terminal and two bridging alkynyl ligands were obtained from toluene. In contrast, recrystallization of the scandium trimethylsilylacetylide complex from toluene induced alkynyl coupling and yielded dimeric scandium complex with one butatrienediyl and two alkynyl bridging ligands. Upon dissolution in THF, all the aggregated alkynyl/butatrienediyl complexes were rapidly reconverted to the monomeric dialkynyl complexes as a result of THF coordination to the rare earth metal atoms.