Preparation, characterization, structure determination of electrochemical studies and crystal salicylaldehyde-aroylhydrazone, ferrocenyl-aroylhydrazone and salicylaldehyde-ferrocenoylhydrazone complexes of indium

The reaction of triethylindium with salicylaldehyde-aroylhydrazone, C6H4(o- OH)-CHNNH-C(O)C6H4-X (X =p-H, p-OCH3, p-NO2, m-NO2, o-OH), yields the tetra hydrofuran (THF) adduct of (C14H9N2O2X)(2)InC2H5. With formylferrocenyl-aro ylhydrazones C5H5FeC5H4-CHNNH-C(O)C6H4-X (X=p-H, p-OCH3, p-NO2, m-NO2, P-Cl , o-Cl), the diethylindium-hydrazone complex, (C18H14N2OFeX)In(C2H5)(2), wa s formed. With salicylaldehyde-ferrocenoylhydrazone, C6H4(o-OH)-CHNNH-C(O)C 5H4FeC5H5, the monohydrazone complex (C18H15N2O2Fe)In(C2H5)(2) tetrahydrofu ran solvate was obtained. The crystal structures of the p-OCH3 derivatives of the first two series of complexes and of the ferrocenoylhydrazone deriva tive were determined. In the solid state, the three complexes are dimers, c ontaining a set of seven, three and five fused rings, respectively. In ever y case, it was observed a symmetric anti arrangement of fused rings in rela tion to a central In2O2 four-membered ring, resulting in a configuration th at resembles a chair. Cyclic voltammetric studies on the ferrocenylaroylhyd razone complexes revealed electron transference from the ferrocene group to wards the indium atom, while for the salicilaldehyde-ferrocenoyl complex th is was not observed. (C) 2001 Elsevier Science B.V. All rights reserved.