1. Strong Exchange Coupling in a Trimetallic Radical-Bridged Cobalt(II)-Hexaazatrinaphthylene Complex.
- Author
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Moilanen, Jani O., Chilton, Nicholas F., Day, Benjamin M., Pugh, Thomas, and Layfield, Richard A.
- Subjects
AMIDES ,MAGNETIC materials ,ANTIFERROMAGNETIC materials ,COBALT ,POTASSIUM - 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. [ABSTRACT FROM AUTHOR]- Published
- 2016
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