A new fused ring compound 2,9-dimethyl-1,10-dihydro-dicyclopenta[a,h]naphthalene (VI), (H2L), has been synthesized from naphthalic anhydride. Two organometallic binuclear complexes, [(CpFe)-Fe-*-L-FeCp*] (1) and the mixed valence compound, [(CpFe)-Fe-*-L-FeCp*](+)-BF4- (2) have been characterized by spectroscopic and electrochemical techniques. The structure resolution of (1) by single crystal X-ray diffraction shows that the two organometallic fragments (CpFe)-Fe-* are in an anti position. Cyclic voltammetry exhibits a potential difference of 348 mV between both redox peaks. The Mossbauer investigation at different temperatures shows a uniform environment for the neutral compound (1) and two sites, assigned to Fe2+ and Fe3+ for the compound (2). The information gathered by all the previously mentioned techniques indicates that the studied binuclear complex belongs to the mixed valence class II complexes according to the classification of Robin and Day. (c) 2004 Elsevier B.V. All rights reserved.