Metal-Helix Frameworks Formed by μ₃ -NO₃ ^- 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 μ₃ -NO₃ ^- to join heterometallic clusters (Cu₁₀ Dy₂ ) 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 μ₃ -NO₃ ^- exist, three of which are involved in the linkage of the double-helix chain. Each μ₃ -NO₃ ^- is connected to three adjacent Cu₁₀ Dy₂ . 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.