Angular and Distance Dependence of the Magnetic Properties of Oxo-Bridged Iron(III) Dimers

Abstract

The magnetic properties of oxo-bridged oxo-(carboxylato)-bridged and oxo-bis(carboxylato)-bridged iron(III) dimers are found to depend on the iron−(μ-O) distance as well as on the iron−(μ-O)−iron angle. With an angular and radial overlap model we account for both these dependencies. The use of an angular overlap model allows us to separate the σ donor properties of oxide as a ligand into the sσ and pσ contributions.

Supramolecular Complexation of Polynuclear Aqua Ions: A Crown Ether Adduct of aμ-Oxo-Bridged Iron(III) Aqua Dimer

“…Weihe and Güdel [19] recently analyzed the dependence of J on the Fe-O-Fe angle f and the average FeÀO distance r by using the angular and radial overlap model. They found that calculated J values increased with decreasing values of r and f. Our values of r 1.784(1) and f 169.6(6)8 fit precisely on the J À 100 cm À1 curve in Figure 3 of reference [19], in very good agreement with the observed J value. The model is therefore able to predict J values for new Fe-O-Fe complexes such as 1.…”

The Molecular and Electronic Structure of Symmetrically and Asymmetrically Coordinated, Non-Heme Iron Complexes Containing [FeIII(μ-N)FeIV]4+ (S=3/2) and [FeIV(μ-N)FeIV]5+ (S=0) Cores

“…[b] Calculated coupling constant according to the expression given by Gorun and Lippard [39] and in parenthesis that of Weihe and Güdel. [40] [c] Paramagnetic impurity with S 5 2, given in molar percentage. (1.44 ± 1.39 mm s À1 for 5).…”

“…On the other hand, Weihe and Güdel [40] have recently derived a similar equation [Eq. (17)] which correlates J with R and F.…”

Salicylaldoxime-Supported Nona- and Tetrametallic Fe^III Cages

“…7). It is interesting to compare the exchange interactions for complexes 2 (mediated by oxime -N-O-and O 2-) and 6 (mediated by oxime -N-O-and -OR), with the former almost five times stronger than the latter [58]. We can also compare the data for 6 to that previously reported for the complex [Fe 4 F 4 (Ph-sao) 4 (py) 4 ].…”