Trinuclear Oxo‐Centered Iron and Iron/Nickel Clusters – Ligand‐Controlled Homo/Hetero Valency

Abstract

Abstract Cleavage of the all‐iron( III ) μ 2 ‐O 2– ‐linked dimer [Fe III 3 O(L) 2 ‐(OAc) 4 ] 2 O ( 3 ) with lithium chloride yields [Fe III 3 O(L) 2 (OAc) 4 ]Cl ( 4 ) and with sodium benzoate, in combination with complete acetate‐to‐benzoate coligand exchange, gives [Fe III 3 O(L) 2 ‐(OBz) 4 ]OBz ( 5 ). Reduction of the all‐Fe III complex 5 [Fe/L/OBz = 3:2:(4+1)] with sodium iodide affords the homonuclear mixed‐valent cluster [Fe II Fe III 2 O(L) 3 (OBz) 3 ] ( 6 ) (Fe/L/OBz = 1:1:1) and requires fundamental coligand‐to‐ligand exchange. Likewise, when the all‐Fe III dimer [Fe III 3 O(L) 2 (OAc) 4 ] 2 O ( 3 ) (Fe/L/OAc = 3:2:4) is cleaved with nickel acetate, the mixed‐valent heteronuclear complex [Ni II Fe III 2 O(L) 3 (OAc) 3 ] ( 7 ) (M/L/OAc = 1:1:1) is formed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)