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+.