A heptanuclear Fe(II)-Fe(III)6 system with twelve unpaired electrons

The pentadentate ligand (LH2)-L-5 = saldptn = N,N'-bis(1-hydroxy-2-benzyliden)-1,7-diamino-4-azaheptane has been prepared by a Schiff base condensation between 1,7-diamino-4-azaheptane and the corresponding salicyaldehyde. Its complexation with Fe(III) gave the high-spin (S = 5/2) complex of [Fe-III(L-5)Cl]. This precursor was combined with [Fe(CN)(6)](4-) and a blue heptanuclear complex [Fe-II{(CN)Fe-III(L-5)}(6)]Cl-2 resulted. This system belongs to the class of high-spin molecules possessing twelve unpaired electrons (S = 6) as proven by the magnetic susceptibility measurements and Mossbauer spectra. (C) 2000 Elsevier Science S.A. All rights reserved.