Iron Complexes with the Alcoholato Donor‐Rich Ligand 4‐tert‐Butyl‐2,6‐bis(hydroxymethyl)phenol: Synthesis and Characterization of a Tetra‐Anionic Fe₂ Complex and a Neutral Fe₁₀Na₄ Complex

The reaction of 4‐ tert ‐butyl‐2,6‐bis(hydroxymethyl)phenol (H 3 L) with Fe III ions in methanol in the presence of an excess of NaOH afforded the tetra‐anionic dinuclear complex Na 4 [(HL) 4 Fe III 2 (CO 3 )]·11MeOH·3H 2 O ( 1 ). Changing the solvent to an ethanol/dme (dme = 1,2‐dimethoxyethane) mixture led to the formation of the decanuclear complex [(HL) 12 Fe III 10 Na 4 (µ 4 ‐O) 4 (µ 3 ‐OH) 2 (dme) 2 (EtOH) 2 ]·2dme·8EtOH ( 2 ). The Mössbauer spectra of 1′ and 2 at 80 K are consistent with high spin Fe III sites in distorted octahedral O 6 coordination environments. Compound 1 consists of a tetra‐anionic dinuclear iron complex with the unprecedented [Fe III (μ 2 ‐OBz) 2 (μ 2 ‐CO 3 )Fe III ] 2+ core. Compound 2 contains a core of hydrous ferric oxide produced by a modified hydrolysis of Fe III ions in the presence of the ligand. Eight benzyl alcohol groups are located on the surface of 2 leading to a 2D network structure by intermolecular hydrogen bonding. The temperature dependence of the magnetic susceptibilities of 1′ and 2 indicates antiferromagnetic interactions between the ferric ions. The data for 1′ were fitted with J = −4.4 cm −1 and g = 1.98, H = −2 J S 1 S 2 . (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)