Mossbauer effect spectroscopy, oxygen

The magnetic properties of the new solid solution series SrFe Rui 3 3, (0 < X < 0.5) with distorted perovskite structure, where iron substitutes exclusively as Fe(in) thereby causing oxygen deficiency, has also been studied by Greenwood s group [147] using both u and Fe Mossbauer spectroscopy. Iron substitution was found to have little effect on the magnetic behavior of Ru(IV) provided that X remains small (x < 0.2). 

A particular method for studying complexes of iron is Mossbauer spectroscopy [7]. For instance, a- and p modifications of Fe(Pc) were studied by this method [8], and the dioxygen derivatives, as well. It was found that the oxygen molecule interacts with the complex, and (p-Oxo)-bis-phthalocyaninato-iron(lll) is formed [9]. The stability of the complex depends strongly on the solvents, e.g. in presence of strong N-bases the Fe ll) form is restored at room temperature, even in presence of oxygen [10]. Further, the Y-zeolite encaged Fe(Pc) was also studied, namely stabilization of the pyridine complex, Fe(Pc)(Py)2, as well as the effects of preparation conditions and presence of various counterions in the framework (Na, K, Rb) on the formation of Fe(Pc)(Py)2 are reported [11-13]. 

Fuchsman and Caughey (1967), in order to examine the properties of oxygenated hemes, have prepared pure oxo-2,4-diacetyldeuteroporphyrin IX dimethyl ester iron. From ESR and Mossbauer spectroscopy and measurement of the infrared absorption of the acetyl carbonyl, the effective oxidation state of iron in the complex appeared to be +3. Infrared absorption attributable to oxygen was close to the expected frequency for free Oj, and was suggestive of binding parallel to the heme plane. 

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