Lanthanide Identity Governs Guest-Induced Dimerization in LnIII[15-MC
N(L-pheHA)-5])3+ Metallacrowns |
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| Authors: | Prof Carmelo Sgarlata Bernadette L Schneider Valeria Zito Dr Rossella Migliore Prof Matteo Tegoni Prof Vincent L Pecoraro Prof Giuseppe Arena |
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| Institution: | 1. Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale Andrea Doria 6, 95125 Catania, Italy;2. Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109 USA;3. Institute of Crystallography, National Research Council (CNR), S.S. Catania, Via P. Gaifami 18, 95126 Catania, Italy;4. Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17?A, 43124 Parma, Italy |
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| Abstract: | Series of lanthanide-containing metallic coordination complexes are frequently presented as structurally analogous, due to the similar chemical and coordinative properties of the lanthanides. In the case of chiral (LnIII15-MC N(L-pheHA)-5])3+ metallacrowns (MCs), which are well established supramolecular hosts, the formation of dimers templated by a dicarboxylate guest (muconate) in solution of neutral pH is herein shown to have a unique dependence on the identity of the MC's central lanthanide. Calorimetric data and nuclear magnetic resonance diffusion studies demonstrate that MCs containing larger or smaller lanthanides as the central metal only form monomeric host-guest complexes whereas analogues with intermediate lanthanides (for example, Eu, Gd, Dy) participate in formation of dimeric host-guest-host compartments. The driving force for the dimerization event across the series is thought to be a competition between formation of highly stable MCs (larger lanthanides) and optimally linked bridging guests (smaller lanthanides). |
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| Keywords: | calorimetry diffusion ordered NMR host-guest systems lanthanides metallacrowns |
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