The molecular and electronic structure of the asymmetric, trinuclear complex [LFe^III(μ-O) (μ-piv)₂Fe^III(μ-OH)(μ-piv)₂Fe^III(pi

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• 作者：Hummel ; Helga ; Bill ; Eckhard ; Weyhermü ; ller ; Thomas ; Wieghardt ; Karl
• 关键词：Crystal structures ; Iron complexes ; Oxo-bridged complexes ; Hydroxo-bridged complexes
• 刊名：Inorganica Chimica Acta
• 出版年：1999
• 出版时间：August, 1999
• 年：1999
• 卷：291
• 期：1-2
• 页码：258-265
• 全文大小：204 K

文摘

The synthesis and molecular structure as determined by single-crystal X-ray crystallography of the neutral complex [LFe^III(μ-O)(μ-piv)₂Fe^III(μ-OH)(μ-piv)₂Fe^III(piv)₂]·C₆H₅CH₃ (1) are described (L=1,4,7-trimethyl-1,4,7-triazacyclononane; piv=pivalate(1-)). The electronic structure of 1 has been established by temperature-dependent susceptibility measurements (2–295 K), UV–Vis, EPR, and Mössbauer spectroscopy. The molecule possesses an S_t=5/2 ground state. The two high-spin ferric ions bridged by an oxo group are strongly antiferromagnetically coupled (H=−2JS₁S₂; S₁=S₂=5/2; J₁₂=−100 cm⁻¹) whereas those bridged by a hydroxo group are less strongly antiferromagnetically coupled (J₂₃=−14 cm⁻¹). Complex 1 has been fully characterized by variable-temperature zero- and applied-field Mössbauer spectroscopy.