Heterometallic Compounds Assembled from Ferrocene-Containing Bisthiosemicarbazone Clips

Heteropolynuclear organometallic compounds have been constructed by using the ferrocene-based ligand H₂L, [NH₂SCNHNC(CH₃)(C₅H₄)]₂Fe. Reaction of the ligand H₂L with the cobalt(II) salt gave a tetranuclear helicate Co₂Fe₂ (1) with two ferrocene-based clips wrapped around the two cobalt atoms. The chiral helicates recognized the neighbors with same chirality through intermolecular hydrogen bonding between the thiosemicarbazone moieties to form a one-dimensional chiral channel. Reaction of the ligand H₂L with the cadmium(II) salt afforded a tetranuclear dimeric compound Cd₂Fe₂ (2), with two symmetric related parts bridged through two sulfur atoms. Reaction of the ligand H₂L with the copper(I) salt, in the presence of triethylamine, resulted in a hexanuclear compound Cu₄Fe₂ (3) with a crownlike Cu₄S₄ octagon similar to that of S₈ sited inside and two ferrocene-containing ligands positioned outside. Electrochemical measurements were displayed to investigate the redox communications between the ferrocene moieties through metal centers.