Platinum complexes having redox-active PPh2CCFc and/or CCFc as terminal or bridging ligands

Abstract

A series of heteronuclear-Pt(ii) complexes containing ferrocenylethynyl units linked directly (Pt-C[triple bond]CFc) or through a phosphorous atom (Pt-PPh(2)C[triple bond]CFc) to the platinum center is reported. The reaction of derivative [cis-Pt(R(F))(2)(PPh(2)C[triple bond]CFc)(2)] (R(F) = C(6)F(5)) with the solvate complex [cis-Pt(R(F))(2)(thf)(2)] leads to the formation of an asymmetrical heteronuclear diplatinum complex [{Pt(R(F))(2)(mu-1kappaP:2eta(2)-PPh(2)C[triple bond]CFc)(2)}Pt(R(F))(2)] having the "cis-Pt(R(F))(2)" fragment coordinated to the triple bonds of both ferrocenylethynylphosphine units, while treatment of [cis-Pt(C[triple bond]CFc)(2)(PPh(2)C[triple bond]CR)(2)] (R = Fc , Ph , tBu ) with the same solvate [cis-Pt(R(F))(2)(thf)(2)], affords double ferrocenylacetylide-bridged diplatinum systems [{Pt(PPh(2)C[triple bond]CR)(2)(mu-eta(1):eta(2)-C[triple bond]CFc)(2)}Pt(R(F))(2)] . The solid-state structures of [cis/trans-Pt(R(F))(2)(PPh(2)C[triple bond]CFc)(2)] /, [cis-Pt(R(F))(2)(PPh(2)C[triple bond]CFc)(tht)] (tht = tetrahydrothiophene), [{Pt(R(F))(2)(mu-1kappaP:2eta(2)-PPh(2)C[triple bond]CFc)(2)}Pt(R(F))(2)] and [{Pt(PPh(2)C[triple bond]CtBu)(2)(mu-eta(1):eta(2)-C[triple bond]CFc)(2)}Pt(R(F))(2)] have been determined by X-ray diffraction methods. The electronic spectra and the electrochemical behaviour of all monoplatinum derivatives are discussed, showing a different extent of interaction between the remote ferrocenyl groups when they belong to PPh(2)C[triple bond]CFc or C[triple bond]CFc ligands. For the diplatinum systems and , containing bridging (kappaP:eta(2)-PPh(2)C[triple bond]CFc ) or (eta(1):eta(2)-C[triple bond, length as m-dash]CFc ) ligands, their electrochemical properties were also compared with the parent precursors.