Abstract
One-electron reduction of the complex [(TPyA)2Fe II2(NPhL2-)]2+ (TPyA = tris(2-pyridylmethyl)amine, NPhLH2 = azophenine = N,N′,N″,Nâ€́-tetraphenyl-2,5-diamino-1, 4-diiminobenzoquinone) affords the complex [(TPyA)2Fe II2(NPhL3-•)]+. X-ray diffraction and Mössbauer spectroscopy confirm that the reduction occurs on NPhL2- to give an S = 1/2 radical bridging ligand. Dc magnetic susceptibility measurements demonstrate the presence of extremely strong direct antiferromagnetic exchange between S = 2 FeII centers and NPhL3-• in the reduced complex, giving an S = 7/2 ground state with an estimated coupling constant magnitude of |J| ≥ 900 cm-1. Mössbauer spectroscopy and ac magnetic susceptibility reveal that this complex behaves as a single-molecule magnet with a spin relaxation barrier of Ueff = 50(1) cm-1. To our knowledge, this complex exhibits by far the strongest magnetic exchange coupling ever to be observed in a single-molecule magnet.
Original language | English (US) |
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Pages (from-to) | 16845-16848 |
Number of pages | 4 |
Journal | Journal of the American Chemical Society |
Volume | 135 |
Issue number | 45 |
DOIs | |
State | Published - Nov 13 2013 |
ASJC Scopus subject areas
- Catalysis
- General Chemistry
- Biochemistry
- Colloid and Surface Chemistry
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CCDC 969355: Experimental Crystal Structure Determination
Jeon, I.-R. (Creator), Park, J. G. (Creator), Xiao, D. J. (Creator) & Harris, T. D. (Creator), Cambridge Crystallographic Data Centre, 2013
DOI: 10.5517/cc11jpjs, http://www.ccdc.cam.ac.uk/services/structure_request?id=doi:10.5517/cc11jpjs&sid=DataCite
Dataset
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CCDC 969356: Experimental Crystal Structure Determination
Jeon, I.-R. (Creator), Park, J. G. (Creator), Xiao, D. J. (Creator) & Harris, T. D. (Creator), Cambridge Crystallographic Data Centre, 2013
DOI: 10.5517/cc11jpkt, http://www.ccdc.cam.ac.uk/services/structure_request?id=doi:10.5517/cc11jpkt&sid=DataCite
Dataset