Synthesis, Spectroscopy, and Redox Studies of Ferrocene-Functionalized Coinage Metal Alkyne Complexes.

Ethynylferrocene (FcC≡CH) was utilized as a redox-active metalloligand for the synthesis of polynuclear coinage metal complexes. The reaction of [FcC≡CLi] with tri- tert-butylphosphine metal chlorides [tBu3P-MCl] (M = Au, Ag, Cu) yielded different heteronuclear ferrocene-funtionalized alkyne complexes featuring metallophilic interactions. Furthermore, the redox properties of the ferrocenyl-functionalized tetracopper complex were investigated by cyclic voltammetry and UV-vis-near-IR spectroelectrochemistry. They indicate the compounds' redox-rich nature and a weak electronic coupling between the redox-active ferrocenyl units over a large distance.