Ground Spin State Variation in Carboxylate‐Bridged Tetranuclear [Fe₂Mn₂O₂]⁸⁺ Cores and a Comparison with Their [Fe₄O₂]⁸⁺ and [Mn₄O₂]⁸⁺ Congeners

Abstract

Syntheses of ten new tetranuclear complexes containing the [M A (µ 3 -O) 2 M B ] 8+ butterfly core [M A = M B = Fe III (1 and 2), M A = M B = Mn III (3 and 4) and M A = Fe III , M B = Mn III (5−10)]using 1,4,7-trimethyl-1,4,7-triazacyclononane (L) as the capping ligand, salicylaldoximato dianion (salox 2− ) and six different carboxylate anions as bridging ligands, are described. (8) were determined by X-ray crystallography. The complexes are isostructural, with M III ions disposed in a butterfly core where bridging between the M III ions occurs via two µ 3 -oxo anions. In complexes 5, 6 and 8 the ''wing-tip'' positions of the butterfly are occupied by the LFe 3+ units, whereas the ''body'' metal ions are d 4 high-spin Mn III ions. Complexes 1−10 have been characterised by variable-tem- [a]

Iron(III)‐Pivalate‐Based Complexes with Tetranuclear {Fe4(μ3‐O)2}8+ Cores and N‐Donor Ligands: Formation of Cluster and Polymeric Architectures

“…[16,[19][20][21][22][23] . We have summarized several characteristic data of these compounds in [22] and [L 2 Fe 4 (μ 3 -O) 2 (Ph 2 C(OH)CO 2 ) 3 (sao) 2 ] (ClO 4 ), [25] in which L = 1,4,7-trimethyl-1,4,7-triazacyclononane and H 2 sao = salicylaldoxime, are the exceptions from this family. They have atypical values of both bond lengths and angles as well as unusual conformations of their basic cores.…”

A magnetostructural study of linear NiIIMnIIINiII, NiIICrIIINiII and triangular NiII3 species containing (pyridine-2-aldoximato)nickel(ii) unit as a building block

“…The manganese-containing complex 1 does not provide signals for unambiguous characterization which is in accord with our earlier experience. 21 Cyclic voltammograms (CV) of complexes 1-3 have been recorded in CH 2 Cl 2 solutions containing 0.1 M [(n-Bu) 4 N]PF 6 in the potential range −1.50 to +1.25 V vs Fc + /Fc. Only the CV of complex 3 afforded one reversible oxidation process, at +0.241 V vs Fc + /Fc, which is shown in Fig.…”

Asymmetric Heterodinuclear FeIIIMII (M = Zn, Cu, Ni, Fe, Mn), CoIIIFeII and FeIICoIII Species: Synthesis, Structure, Redox Behavior, and Magnetism

“…Analysis of the susceptibility data indicates the presence of antiferromagnetic exchange interactions that decrease in the following order: Fe III M A M B , [9] M A M B M A , [10] and M A M B M B M A [11] (M A , M B being two different metal ions). In addition, we have synthesized asymmetric heterotrinuclear complexes with cores M A M B M C [12] and butterfly cores [13] (M A ) 2 unit, where L represents the tridentate cyclic amine 1,4,7-trimethyl-1,4,7-triazacyclononane. [9,10] In this paper, we explore the effects of using Fe III …”