Selective Self-Assembly of Hexameric Homo- and Heteropolymetallic Lanthanide Wheels: Synthesis, Structure, and Photophysical Studies
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- 作者：Xiao-Yan Chen ; Yann Bretonniè ; re ; Jacques Pé ; caut ; Daniel Imbert ; Jean-Claude Bü ; nzli ; Marinella Mazzanti
- 刊名：Inorganic Chemistry
- 出版年：2007
- 出版时间：February 5, 2007
- 年：2007
- 卷：46
- 期：3
- 页码：625 - 637
- 全文大小：284K
- 年卷期：v.46,no.3(February 5, 2007)
- ISSN：1520-510X
文摘
A rational approach to the formation of pure heteropolymetallic lanthanide complexes that uses a two-step assemblystrategy and exploits the different size requirements of the two metals included in the final structure is described.The investigation of the assembly of [LnL2](Otf) (L = 2,2':6',2' '-terpyridine-6-carboxylate) complexes into hexametallicrings hosting an additional hexacoordinated lanthanide cation was crucial for the development of this strategy. Theformation and size of the cyclic assembly are controlled by the ionic radius and by the coordination number of thelanthanides. The rather high luminescence quantum yield of the heptaeuropium complex (25%) indicates that thering structure is well adapted to include highly luminescent lanthanide complexes in nanosized architecture. Theuse of a stepwise synthetic strategy leads to the selective assembly of large heteropolymetallic rings. The additionof a smaller lanthanide ion to the [EuL2](Otf) complex in anhydrous acetonitrile leads selectively to heterometallicspecies with the Eu ions located on the peripheral sites and the smaller ion occupying only the central site. Thehigh selectivity is the result of the different size requirements of the two metal sites present in the cyclic structure.The heterometallic structure of the isolated [Lu
(EuL2)6](Otf)9 complex was confirmed by X-ray diffraction and byhigh resolution solid-state photophysical studies. The described synthetic approach allowed us to obtain the firstexample of selective assembly of two different lanthanide ions in a large polymetallic structure characterized insolution and in the solid state and will make the isolation of planned dimetallic combinations presenting differentlanthanide emitters in the peripheral sites possible.
(EuL2)6](Otf)9 complex was confirmed by X-ray diffraction and byhigh resolution solid-state photophysical studies. The described synthetic approach allowed us to obtain the firstexample of selective assembly of two different lanthanide ions in a large polymetallic structure characterized insolution and in the solid state and will make the isolation of planned dimetallic combinations presenting differentlanthanide emitters in the peripheral sites possible.