Triangles and tetrahedra: metal directed self-assembly of metallo-supramolecular structures incorporating bis-β-diketonato ligands
作者:Jack K. Clegg、Leonard F. Lindoy、Boujema Moubaraki、Keith S. Murray、John C. McMurtrie
DOI:10.1039/b403673e
日期:——
The interaction of six aryl-linked bis-β-diketones, including a new naphthylene linked species, with copper(II), iron(III) and, in one instance gallium(III), has been investigated with the aim of obtaining metallo-supramolecular assemblies exhibiting different geometries. New examples of two assembly types incorporating the above bis-β-diketones (L) were generated. The first type is represented by a range of molecular triangles of formula [Cu3(LâH2)3](solvent)n while the second is given by a corresponding selection of less-common neutral molecular tetrahedra of formula [Fe4(LâH2)6](solvent)n as well as [Ga4(LâH2)6]·8.5THF·0.5H2O; an example of each type has been characterised by X-ray crystallography. A magnetochemical investigation of [Fe4(3âH2)6]·6THF is reported. The susceptibility is Curie like and consistent with very weak coupling occurring between the iron(III) d5
(high spin) centres. The X-ray structures of two trinuclear copper(II) as well as a tetranuclear iron(III) and a tetranuclear gallium(III) assembly confirm their discrete triangular and tetrahedral geometries, respectively. The structure of the gallium(III) species is closely related to that of the corresponding iron(III) species. The tetrahedral structures provide rare examples of such assemblies encapsulating guest solvent molecules â in each case tetrahydrofuran is incorporated in the central cavity.
研究了包括一种新型萘烯连接物种在内的六种芳基连接的双β-二酮与铜(II)、铁(III)以及在某一种情况下的镓(III)的相互作用,旨在获得展现出不同几何结构的金属超分子组装体。生成了两种包含上述双β-二酮(L)的新组装类型实例。第一种类型由一系列分子三角形表示,分子式为[Cu3(L–H2)3](溶剂)n,而第二种类型由较少见的中性分子四面体组成,分子式为[Fe4(L–H2)6](溶剂)n以及[Ga4(L–H2)6]·8.5THF·0.5H2O;每种类型的例子通过X射线晶体学进行了表征。报道了[Fe4(3–H2)6]·6THF的磁化学研究。磁化率呈居里型,与铁(III) d5(高自旋)中心之间非常弱的耦合相一致。两种三核铜(II)以及一个四核铁(III)和一个四核镓(III)组装的X射线结构证实了它们分别是离散的三角形和四面体几何结构。镓(III)物种的结构与相应的铁(III)物种的结构密切相关。四面体结构提供了罕见的此类组装体封装客体溶剂分子的例子——在每种情况下,四氢呋喃都包含在中心腔体内。