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Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
Bonding Features and Magnetic Ordering in Thiolate-Bridged Copper-Nickel Clusters Synthesized at Elevated Temperature
Arijit Jana1, Yaofeng Wang1, Lukas Guggolz1
1Institute of Nanotechnology, Karlsruhe Institute of Technology (INT), Kaiserstraße 12, 76131, Karlsruhe, Germany.
Abstract:
Atomically-precise heterometallic nickel-based clusters are an emerging class of functional nanomaterials with intriguing optical and magnetic properties. However, synthetic challenges restrict their exploration in comparison to heterometallic coinage metal-based nanoclusters. This study presents a single-step synthesis of the two new thiolate-bridged copper-nickel cluster compounds [Cu2Ni6S3(MCP)6] (1) and [Cu2Ni6(MCP)12I2] (2) (MCPH = 2-mercaptopyridine; MCP = deprotonated 2-mercaptopyridine) at an elevated temperature. Single-crystal X-ray diffraction reveals that 1 is composed of polymeric strands of linked cluster units. Each of the units exhibit a bicapped trigonal prismatic {Cu2Ni6} core that is surrounded by three capping sulfide and six MCP ligands. Cluster 2 features individual clusters, each bearing a hexagonal bipyramidal {Cu2Ni6} core with twelve MCP units as well as two iodide ions as additional ligands. In spite of the different aggregation modes, both of these clusters exhibit molecule-like characteristic multiband optical absorption features. Temperature-dependent magnetic susceptibility measurements for 1 revealed dual antiferromagnetic and ferromagnetic coupling among six Ni(II) centers with an S = 2 ground state, while 2 exhibits strong ferromagnetic coupling, whereby the susceptibility increases with decreasing temperature to an S = 4 ground state. This study is an example of solvothermal synthesis of related ligand-supported copper-nickel cluster compounds with structure-specific optical and magnetic properties.
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