Perfluorinated Ligands Induce Meridional Metal Stereochemistry to Generate M8L12, M10L15, and M12L18 Prisms

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• 作者：Marion Kieffer ; Ben S. Pilgrim ; Tanya K. Ronson ; Derrick A. Roberts ; Mina Aleksanyan ; Jonathan R. Nitschke
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：June 1, 2016
• 年：2016
• 卷：138
• 期：21
• 页码：6813-6821
• 全文大小：774K
• 年卷期：0
• ISSN：1520-5126

文摘

Meridional (mer) coordination promotes the generation of larger and lower-symmetry prismatic metallosupramolecular structures, in contrast with the facial (fac) coordination common to smaller and higher-symmetry polyhedra. Here, we describe a general route to the selective formation of large metallosupramolecular prisms that contain exclusively mer-coordinated metal vertices. The use of 2-formylpyridine subcomponents that contain perfluorophenylene substituents at their 5-positions resulted in stereoselective formation of the iron(II) complexes from these subcomponents. Only mer vertices were observed, as opposed to the statistical fac/mer mixture otherwise generated. This mer-selective self-assembly could be used to prepare tetragonal (M₈L₁₂), pentagonal (M₁₀L₁₅), and hexagonal (M₁₂L₁₈) prisms by taking advantage of the subtle selectivities imposed by the different anilines and counterions employed. The equilibrium between the tetragonal and pentagonal prism followed a linear free-energy relationship, with the ratio between structures correlating with the Hammett σ_p⁺ parameter of the incorporated aniline. The contrasting preferences of the fluorinated and nonfluorinated ligands to generate prisms and tetrahedra, respectively, were quantified energetically, with the destabilization increasing linearly for each “incorrect ligand” incorporated into either structure.