Crystal structure of (μ-oxo)bis{aquatris(2-pyridylmethyl)amine}iron(III) perchlorate

Abstract The complex [{Fe(tmpa)(H 2 O)} 2 O](ClO 4 ) 4 ·3H 2 O·0.25C 2 H 5 OH contains a near-linear, dinuclear cation (FeOFe ∠=176.1(5)°) with average Fe–μ-O 2− (1.783(7) A), Fe–apical N (2.244(11) A), Fe–pyridyl N (2.125(10) A) and Fe–O(aqua) (2.082(8) A) bond lengths that are essentially identical for the two iron centers. Both tmpa apical nitrogen atoms are trans to the oxo bridge, in contrast to the unsymmetric structure of [(OH)(tmpa)FeOFe(tmpa)(H 2 O)] 3+ , for which one apical N atom is trans to the μ-O 2− group while the other is trans to the hydroxo ligand.