Strong Exchange Coupling in a Trimetallic Radical‐Bridged Cobalt(II)‐Hexaazatrinaphthylene Complex |
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| Authors: | Dr. Jani O. Moilanen Dr. Nicholas F. Chilton Dr. Benjamin M. Day Dr. Thomas Pugh Prof. Dr. Richard A. Layfield |
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| Affiliation: | 1. School of Chemistry, The University of Manchester, Manchester, UK;2. Department of Chemistry, University of Jyvaskala, Jyvaskala, Finland |
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| Abstract: | Reducing hexaazatrinaphthylene (HAN) with potassium in the presence of 18‐c‐6 produces [{K(18‐c‐6)}HAN], which contains the S=1/2 radical [HAN].?. The [HAN].? radical can be transferred to the cobalt(II) amide [Co{N(SiMe3)2}2], forming [K(18‐c‐6)][(HAN){Co(N′′)2}3]; magnetic measurements on this compound reveal an S=4 spin system with strong cobalt–ligand antiferromagnetic exchange and J≈?290 cm?1 (?2 J formalism). In contrast, the CoII centres in the unreduced analogue [(HAN){Co(N′′)2}3] are weakly coupled (J≈?4.4 cm?1). The finding that [HAN].? can be synthesized as a stable salt and transferred to cobalt introduces potential new routes to magnetic materials based on strongly coupled, triangular HAN building blocks. |
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| Keywords: | cobalt hexaazatrinaphthylene magnetism non-innocent ligands radicals |
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