Charge-Separated and Molecular Heterobimetallic Rare Earth-Rare Earth and Alkaline Earth-Rare Earth Aryloxo Complexes Featuring Intramolecular Metal-π-arene Interactions
Charge-Separated and Molecular Heterobimetallic Rare Earth-Rare Earth and Alkaline Earth-Rare Earth Aryloxo Complexes Featuring Intramolecular Metal-π-arene Interactions
复制标题
DOI：
10.1002/chem.200900229
复制
发表时间：
2009-01-01
影响因子：
4.3
通讯作者：
Zunig, Maria F.
中科院分区：
文献类型：
--
作者：
Deacon, Glen B.;Junk, Peter C.;Zunig, Maria F.
稀土金属(Ln)和潜在的二价稀土金属(Ln‘)或所有碱土金属(Ae)与2，6-二苯基苯酚(HOdpp)在高温(200-250℃)下处理得到了异双金属芳氧基配合物，其结构进行了表征。得到了一系列金属的电荷分离物种[(Ln‘/Ae)(2)(ODPP)(3)][Ln(ODPP)(4)]，证明了二价稀土金属和碱土金属的化学结构相似。异质双金属结构中的[(Ln‘/Ae)(2)(ODPP)(3)](+)阳离子是不寻常的，因为它只由桥联芳氧配体组成。用HODPP在高温下处理碱土金属和Eu金属，得到了分子异双金属物种[AEEu(ODPP)(4)](Ae=Ca，Sr，Ba)。类似地，用HODPP处理金属Ba和金属锶制备了[Basr(ODPP)(4)]。[Ba-2(ODPP)(4)]与[Mg(ODPP)(2)(THF)(2)]在甲苯中反应得到[Ba-2(ODPP)(3)][Mg(ODPP)(3)(THF)]。[(Ln‘/Ae)(2)(ODPP)(3)][Ln(ODPP)(4)][Ln’/Ae)(2)(ODPP)(3)][Ln(ODPP)(4)]络合物不可能进行类似的溶液合成，因为自由金属路线是必不可少的。由于没有额外的给体配体，异双金属配合物的晶体结构具有广泛的pi-Ph-金属相互作用，涉及ODPP配体的侧基苯基，从而使大的正电性金属原子达到配位饱和。在常温下用甲苯/四氢呋喃混合物萃取(含钡化合物)或在高于溶剂沸点的压力下用甲苯萃取(其他产品)可提纯电荷分离的异双金属物种。在给体溶剂中，除含钡外的异双金属络合物被发现裂解成同金属物种。
Treatment of a rare earth metal (Ln) and a potential divalent rare earth metal (Ln') or all alkaline earth metal (Ae) with 2,6-diphenylphenol (HOdpp) at elevated temperatures (200-250 degrees C) afforded heterobimetallic aryloxo complexes, which were structurally characterised. A charge-separated species [(Ln'/Ae)(2)(Odpp)(3)][Ln(Odpp)(4)] was obtained for a range of metals, demonstrating the similarities between the chemistry of the divalent rare earth metals and the alkaline earth metals. The [(Ln'/Ae)(2)(Odpp)(3)](+) cation in the heterobimetallic structures is unusual ill that it consists solely of bridging aryloxide ligands. A molecular heterobimetallic species [AeEu(Odpp)(4)] (Ae=Ca, Sr, Ba) was obtained by treating ail alkaline earth metal and Eu metal with HOdpp at elevated temperatures. Similarly, [BaSr(Odpp)(4)] was prepared by treating Ba metal and Sr metal with HOdpp. Treatment of [Ba-2(Odpp)(4)] with [Mg(Odpp)(2)(thf)(2)] in toluene afforded [Ba-2(Odpp)(3)][Mg(Odpp)(3)(thf)]. Analogous solution-based syntheses were not possible for [(Ln'/Ae)(2)(Odpp)(3)][Ln(Odpp)(4)] complexes, for which the free-metal route was essential. As a result of the absence of additional donor ligands, the crystal structures of the heterobimetallic complexes feature extensive pi-Ph-metal interactions involving the pendant phenyl groups Of the Odpp ligands, thus enabling the large electropositive metal atoms to attain coordination saturation. The charge-separated heterobimetallic species were purified by extraction with toluene/thf mixtures at ambient temperature (Ba-containing compounds) or by extraction with toluene under pressure above the boiling point of the solvent (other products). In donor solvents, heterobimetallic Complexes other than those containing barium were found to fragment into homometallic species.