Metal-Helix Frameworks Formed by μ 3 -NO 3 - with Different Orientations and Connected to a Heterometallic Cu II 10 Dy III 2 Folded Cluster.

Metal nanoclusters have a certain rigidity due to their specific coordination patterns and shapes; thus, they face extreme difficulty in folding into a specific direction to form a double-helix structure and in further interconnecting to form metal-helix frameworks (MHFs). To date, no MHFs have been produced by the formation of heterometallic clusters. Selecting the appropriate "bonding molecules" to bond metal nanoclusters in a specific multiple direction is one of the most effective strategies for designing synthetic MHFs. In this study, we realized for the first time the control of different orientations of μ ₃ -NO ₃ ^- to join heterometallic clusters (Cu ₁₀ Dy ₂ ) and subsequently form a left-handed double helix chain, which further joins to form MHFs. In the structure of the MHFs, four different directions of bridging μ ₃ -NO ₃ ^- exist, three of which are involved in the linkage of the double-helix chain. Each μ ₃ -NO ₃ ^- is connected to three adjacent Cu ₁₀ Dy ₂ . Herein, we extend a new method for designing synthetic double-helix structures and MHFs, thereby further laying the foundation for the development of similar DNA double-helix structures and nucleic acid secondary structures in vitro.
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