Ligand Control of Manganese Telluride Molecular Cluster Core Nuclearity

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• 作者：Bonnie Choi ; Daniel W. Paley ; Theo Siegrist ; Michael L. Steigerwald ; Xavier Roy
• 刊名：Inorganic Chemistry
• 出版年：2015
• 出版时间：September 8, 2015
• 年：2015
• 卷：54
• 期：17
• 页码：8348-8355
• 全文大小：450K
• ISSN：1520-510X

文摘

We report the synthesis, structural diversity, and chemical behavior of a family of manganese telluride molecular clusters whose charge-neutral cores are passivated by two-electron donor ligands. We describe three different core structures: a cubane-type Mn₄Te₄, a prismane Mn₆Te₆, and a dicubane Mn₈Te₈. We use various trialkylphosphines and N-heterocyclic carbenes (NHCs) as surface ligands and demonstrate that the formation of the different cluster core structures is controlled by the choice of ligand: bulky ligands such as PⁱPr₃, PCy₃, or ⁱPr₂NHC (ⁱPr₂NHC = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) form the cubane-type core, while the smaller PMe₃ produces the prismane core. The intermediate-sized PEt₃ produces both cubane and prismane species. These manganese telluride molecular clusters are labile, and the capping phosphines can be replaced by stronger ligands, while the internal core structure of the cluster remains intact. The interplay of structural diversity and ligand versatility and lability makes these clusters potentially useful building blocks for the assembly of larger aggregates and extended structures. We demonstrate the simplest prototype of these solid-forming reactions: the direct coupling of two Mn₄Te₄(ⁱPr₂NHC)₄ units to form the dicubane Mn₈Te₈(ⁱPr₂NHC)₆. We also postulate the prismatic Mn₆Te₆ as the common ancestor of both Chevrel-type M₆E₈ and octanuclear rhombododecahedral M₈E₆ molecular clusters (M = transition metal and E = chalcogen), and we discuss the core structure of our molecular clusters as recognizable building units for the zinc blende and the hypothetical wurtzite lattices of MnTe.