Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
[Fe(OCH3)(2)(dbm)](12): synthesis, solid-state characterization and reactivity of a new molecular ferric wheel
Autore:
Abbati, GL; Caneschi, A; Cornia, A; Fabretti, AC; Gatteschi, D;
Indirizzi:
Univ Florence, Dept Chem, I-50144 Florence, Italy Univ Florence FlorenceItaly I-50144 Dept Chem, I-50144 Florence, Italy Univ Modena & Reggio Emilia, Dept Chem, I-41100 Modena, Italy Univ Modena & Reggio Emilia Modena Italy I-41100 , I-41100 Modena, Italy
Titolo Testata:
INORGANICA CHIMICA ACTA
fascicolo: 1-2, volume: 297, anno: 2000,
pagine: 291 - 300
SICI:
0020-1693(200001)297:1-2<291:[SSCAR>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
IRON(III) IONS; COMPLEX; IRON; CLUSTERS; LIGANDS; RINGS; COPPER;
Keywords:
supramolecular chemistry; magnetic properties; iron complexes; cluster complexes;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
37
Recensione:
Indirizzi per estratti:
Indirizzo: Caneschi, A Univ Florence, Dept Chem, Via Maragliano 75-77, I-50144 Florence, Italy Univ Florence Via Maragliano 75-77 Florence Italy I-50144 aly
Citazione:
G.L. Abbati et al., "[Fe(OCH3)(2)(dbm)](12): synthesis, solid-state characterization and reactivity of a new molecular ferric wheel", INORG CHIM, 297(1-2), 2000, pp. 291-300

Abstract

A novel iron(III) molecular alkoxide, [Fe(OCH3)(2)(dbm)](12) (1), was synthesized by the reaction of ferric chloride with dibenzoylmethane (Hdbm) andan excess of either potassium or cesium methylate in anhydrous methanol. The 12 octahedrally coordinated iron(III) ions are linked by double OCH, bridges in a nonplanar twisted-ring structure, to give the largest cyclic ferric cluster so far reported, containing chemically equivalent bridging units. The quantitative conversion of 1 into hexairon(III) rings [MFe6(OCH3)(12)(dbm)(6)](+) (M = Li, Na) by reaction with excess alkali-metal tetraphenylborates in CH2Cl2/CH3OH 3:1 was studied by H-1 NMR and UV-Vis spectroscopies. The reactions follow pseudo-first-order kinetics with respect to 1, with k(po)(Li) = 1.07(2) x 10(-2) and k(po)(Na) = 1.63(3) x 10(-2) s(-1) at 25 zeta degrees C. The magnetic susceptibility of 1 in the solid state is consistent with antiferromagnetic exchange interactions between the high-spin iron(III) ions and closely follows the behavior predicted for a Heisenberg s = 5/2 quantum-spin chain down to 50 K (J = 22.2 cm(-1) for H = J Sigma(i)S(i)S(i+1) and g = 2.00). At low temperatures the magnetic behavior is dominated by the energy gap between the ground S = 0 and the first excited S = 1 state, which is a consequence of finite-size effects. (C) 2000 Elsevier Science S.A. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 08/07/20 alle ore 07:45:30