Formation of an iron(III) oxo cubane core Fe4(μ4-O)4 from FeCl3 and the unsymmetrical tripodal ligand N[(CH2CH2NH2)(CH2CH2OH)(CH2CH2CH2OH)]

The coordination chemistry of the unsymmetric, aliphatic, tetradentate tripodal ligand N[(CH2CH2NH2)(CH2CH2OH)(CH2CH2CH2OH)] H-4-1 with iron chlorides was investigated. The disodium salt of the deprotonated ligand Na-2(H-2-1) reacts with FeCl3 to yield a yellow precipitate which upon recrystallization from DMSO/CH2Cl2 gives red crystals of the octanuclear iron(III) complex [{(FeCl)-Cl-III(H-2-1)}(4)Fe-4(III)(mu(4)-O)(4)Cl-4] 2 (.) 4CH(2)Cl(2) containing a central Fe-4(mu(4)-O)(4) cubane core. Crystals of 2 (.) 4DMF were obtained by slow oxidation of the green iron(II) complex obtained from ferrous chloride and Na2(H2-1) after recrystallization from DMF The structure determination of 2 (.) 4CH(2)Cl(2) also revealed the presence of the iron(III) oxo cubane core. The core is surrounded by four iron atoms each coordinated by eta(4)-(H-2-1)(2-) and Cl- ligands.