Electroactive Ligands: The First Metal Complexes of Tetrathiafulvenyl−Acetylacetonate

The reaction of tris(alkylthio)tetrathiafulvalene thiolates with 3-chloro-2,4-pentanedione affords tetrathiafulvalene
(TTF) moieties substituted by the acetylacetone function (TTFSacacH), precursors of novel redox-active ligands: 
the acetylacetonate ions (TTFSacac). These TTFSacacHs have been characterized by X-ray diffraction analyses,
and similar trends have been observed, such as a TTF core almost planar and the acetylacetone substituent
located in a plane almost perpendicular to the plane formed by the TTF core. Their chelating ability has been
demonstrated by the formation of the corresponding M(TTFSacac)2(pyridine)2 complexes in the presence of MII(OAc)2·H2O (M = Ni2+, Zn2+). These complexes with TTFSacac moieties, Ni(TTFSacac)2(pyridine)2, 6b, and Zn(TTFSacac)2(pyridine)2, 7b, have been characterized by X-ray diffraction analyses, showing in all structures the
metal(II) center chelated by two TTFacac units in the equatorial plane and the octahedral coordination geometry
around the metal completed by two axial pyridine ligands. Cyclic voltammetry and UV−visible−near infrared
spectroscopic measurements have evidenced a sizable interaction between the two electroactive ligands and the
stabilization of a mixed-valence state in the one-electron oxidized complexes.