New ferrocene based dithiolate ligands

The preparation and characterization of the three ferrocene based dithiolane complexes [(η5-C5H5)Fe(η5-C5H4)NHC(O)(CH2)4CHS2CH2CH2¯]1, [(η5-C5H5)Fe(η5-C5H4)CH2OC(O)(CH2)4CHS2CH2CH2¯]2 and [(η5-C5H5)Fe(η5-C5H4)NHC(O)(CH2)CHS2CH2CH2¯]3, with different spacer groups between the ferrocenyl moiety and the dithiolane unit, are reported. The complexation of 1 and 2, using the oxidative addition of the S–S bonds to Pt(0), is also described, leading to the square planar Pt(II) complexes [Pt(PPh3)2(S2CH2CH2CH-κ2-S,S)(CH2)4C(O)NH(η5-C5H4)Fe(η5-C5H5)] 4 and [Pt(PPh3)2(S2CH2CH2CH-κ2-S,S)(CH2)4C(O)OCH2(η5-C5H4)Fe(η5-C5H5)] 5, respectively. The reduction of the S–S bond in 1 and 2 yields the corresponding dithiols; these can be deprotonated and treated with ClSiMe3 to prepare [(η5-C5H5)Fe(η5-C5H4)NHC(O)(CH2)4CH(SSiMe3)CH2CH2(SSiMe3)] 7 and [(η5-C5H5)Fe(η5-C5H4)CH2OC(O)(CH2)4CH(SSiMe3)CH2CH2(SSiMe3)] 9, respectively. The complexes were characterized via NMR and UV–Vis absorption spectroscopy, cyclic voltammetry and single crystal X-ray diffraction for 1 and 4.

The preparation and characterization of the three ferrocene based dithiolane complexes with different spacer groups between the ferrocenyl moiety and the dithiolane unit, are reported. Complexation using the oxidative addition of the S–S bonds to Pt(0), is also described, leading to square planar Pt(II) complexes (illustrated).Figure optionsDownload as PowerPoint slideHighlights
► Ferrocenyl amide and ferrocenylesters from lipoic acid chloride.
► Oxidative addition to platinum(0) of disulfide linkage to yield cis-dithiolate complex.
► Structural characterization of dithiolane and Pt–dithiolate complex.