Designing molecules for metal-metal electronic communication: synthesis and molecular structure of the couple of heterobimetallic isomers eta6-(2-ferrocenyl) indene]-Cr(CO)3 and eta6-(3-ferrocenyl)indene]-Cr(CO)3

The heterobinuclear isomers [è6-(2-ferrocenyl) indene]-Cr(CO)3 (1) and [è6-(3-ferrocenyl)indene-Cr- (CO)3 (2) have been prepared and the crystal structure determination showed that the Fe(C5H5) and Cr(CO)3 groups in the two molecules are disposed in different conformations with respect to the Cp-indene bridging ligand, cisoid in 1 and transoid in 2. Preliminary electrochemical (CV) and spectroscopic (IR and near-IR) results obtained for the corresponding monooxidized 1+ and 2+ demonstrate the existence of stronger electronic coupling in 1+ than in 2+.