Synthesis and characterization of half-sandwich N-heterocyclic carbene complexes of cobalt and rhodium
Synthesis and characterization of half-sandwich N-heterocyclic carbene complexes of cobalt and rhodium
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DOI：
10.1039/b408750j
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发表时间：
2004-01-01
影响因子：
4
通讯作者：
Tilset, M
中科院分区：
文献类型：
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作者：
Fooladi, E;Dalhus, B;Tilset, M
一系列带有 N-杂环卡宾配体 1,3-二甲基咪唑-2-亚基 (IMes) 的新型半夹心 M(I) 和 M(III) 配合物 (M = Co, Rh) 已被制备和表征。因此，(eta(5)-C5R5) M(IMes)(C2H4) (M = Co, Rh; R = H, Me)是从相应的双(乙烯)配合物(eta(5)-C5R5) M(C2H4)(2)获得的，除了CpRh(IMes)(C2H4)，它是通过新型16电子Rh(I)化合物制备的Rh(IMes)(C2H4)(2)Cl。通过(eta(5)-C5R5) Co(CO)(2)的热CO取代合成了羰基化合物(eta(5)-C5R5) Co(IMes)(CO) (R = H, Me)。从 CpCo(IMes)(CO) 和 I-2 获得抗磁性、明显的 16 电子 Co(III) 化合物 [CpCo(IMes)I](+)[I-3(-)]。最后，分别通过 [CpCo(IMes)I](+)[I-3(-)] 甲基化和 Cp* Rh(Me2SO) Me-2 上的配体交换制备 Co(III) 和 Rh(III) 配合物 CpCo(IMes) Me-2 和 Cp* Rh(IMes) Me-2。通过单晶X射线衍射测定了CpCo(IMes)(CO)、CpRh(IMes)(C2H4)、Cp*Rh(IMes)(C2H4)和Cp*Rh(IMes)Me2的分子结构。基于 X 射线晶体学、核磁共振和红外光谱分析，讨论了强供体和空间要求的 IMes 配体所施加的空间和电子因素。 Rh(I) N,N-杂环卡宾配合物的 (1)J(Rh-C(卡宾)) 和 dRh-C(卡宾) 数据之间的相关性非常差，包括文献数据和本工作。
A series of novel half-sandwich M(I) and M(III) complexes (M = Co, Rh) bearing the N-heterocyclic carbene ligand 1,3-dimesitylimidazol-2-ylidene (IMes) have been prepared and characterized. Thus, (eta(5)-C5R5) M(IMes)(C2H4) (M = Co, Rh; R = H, Me) were obtained from the corresponding bis(ethene) complexes (eta(5)-C5R5) M(C2H4)(2), except for CpRh(IMes)(C2H4) which was prepared via the novel 16-electron Rh(I) compound Rh(IMes)(C2H4)(2)Cl. The carbonyl compounds (eta(5)-C5R5) Co(IMes)(CO) (R = H, Me) were synthesized by thermal CO substitution of (eta(5)-C5R5) Co(CO)(2). A diamagnetic, apparently 16-electron Co(III) compound [CpCo(IMes)I](+)[I-3(-)] was obtained from CpCo(IMes)(CO) and I-2. Finally, Co(III) and Rh(III) complexes CpCo(IMes) Me-2 and Cp* Rh(IMes) Me-2 were prepared by methylation of [CpCo(IMes)I](+)[I-3(-)], and ligand exchange at Cp* Rh(Me2SO) Me-2, respectively. The molecular structures of CpCo( IMes)(CO), CpRh(IMes)(C2H4), Cp* Rh(IMes)(C2H4), and Cp* Rh( IMes) Me2 were determined by single crystal X-ray diffraction. Steric and electronic factors imposed by the strongly donating and sterically demanding IMes ligand are discussed on the basis of X-ray crystallographic, NMR, and IR spectroscopic analyses. Very poor correlations are found between values for (1)J(Rh-C(carbene)) and dRh-C(carbene) data for Rh(I) N,N-heterocyclic carbene complexes including literature data and this work.