EPR insensitivity of the metal-nitrosyl spin-bearing moiety in complexes [LnRuII-NO.]k
A survey of 18 paramagnetic species [LnRu(NO)]k, including seven new examples studied by in situ electrolysis, reveals a surprisingly narrow range of EPR parameters despite a wide variety of ligands such as pyridine, polypyridines, imines, amines, nitriles, phosphanes, carbonyl, cyclopentadienides,...
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2004
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14341948_v_n14_p2902_Frantz http://hdl.handle.net/20.500.12110/paper_14341948_v_n14_p2902_Frantz |
| Aporte de: |
| Sumario: | A survey of 18 paramagnetic species [LnRu(NO)]k, including seven new examples studied by in situ electrolysis, reveals a surprisingly narrow range of EPR parameters despite a wide variety of ligands such as pyridine, polypyridines, imines, amines, nitriles, phosphanes, carbonyl, cyclopentadienides, halides, hydride, hydroxide, thiocyanate or cyanide: g 1 = 2.015 ± 0.02, g2 = 1.990 ± 0.015, g 3 = 1.892 ± 0.03, gav = 1.968 ± 0.02, Δg = g1 - g3 = 0.122 ± 0.037, A 2(14N) = 3.3 ± 0.5 mT. This rather small variability, smaller still if the organometallic compounds are excluded, differs from the wider range of EPR data reported for nitrosyliron species with S = 1/2; apparently, the [RuNO]7 configuration involves a rather invariant and relatively covalent metal-NO interaction. DFT calculations were employed for [(NC)5Ru(NO)]3-to reproduce the EPR data, to evaluate the spin distribution (58% spin density on NO), and to reveal structural changes on reduction such as the Ru-N-O bending and Ru-NO bond lengthening. In addition, the possibility of staggered and eclipsed conformations is discussed. © Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004. |
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