Transformations of Binuclear Iron(II) Pivalate, Fe2(µ-OOCBu ^t)4(NEt3)2, in the Reactions with Air Oxygen and 3,5-Dimethylpyrazole

The extraction of a suspension, which is prepared by mixing of iron dichloride, pivalic acid, and triethylamine, with hexane and keeping of the resulting solution at –5°С in a refrigerator result in the formation of single crystals of the binuclear dimeric lantern Fe2(µ-OOCtBu)4(NEt3)2 (I). The decantation of the single crystals at room temperature gives an orange product oxidized in air to form a red powder. The dissolution of the powder in a benzene–acetonitrile (10 : 1) mixture in air and the subsequent crystallization give single crystals of complex {[Fe3(µ3-O)(OH2)(µ-OOCtBu)5(η2-OOCtBu)[O(CtBu)OHNEt3)] ∙ MeCN} (II). The interaction of the mother liquor with 3,5-dimethylpyrazole (HDmpz) affords complex Fe3(µ3-O)(µ-OOCtBu)6(HDmpz)3 (III). Complexes I–III are characterized by elemental analysis, IR spectroscopy, and X-ray diffraction analysis (СIF files CCDC nos. 1959111 (I), 1959112 (II), and 1959110 (III)).