[Fe(µ 2 -OH) 6 ] 3- Linked Fe 3 O Triads: Mössbauer Evidence for Trigonal µ 3 -O 2- or µ 3 -OH - Groups in Bridged versus Unbridged Complexes.

The syntheses, coordination chemistry, and Mössbauer spectroscopy of hepta-iron(III) complexes using derivatised salicylaldoxime ligands from two categories; namely, 'single-headed' (H 2 L ) and 'double-headed' (H 4 L ) salicylaldoximes are described. All compounds presented here share a [Fe 3 -µ 3 -O] core in which the iron(III) ions are µ 3 -hydroxo-bridged in the complex C1 and µ 3 -oxo-bridged in C2 and C3 . Each compound consists of 2 × [Fe 3 -µ 3 -O] triads that are linked via a central [Fe(µ 2 -OH) 6 ] 3- ion. In addition to the charge balance and microanalytical evidence, Mössbauer measurements support the fact that the triads in C1 are µ 3 -OH bridged and are µ 3 -O bridged in C2 and C3 .