The CuI catalyzed dehydro-halogenation of 1',1'"-diethynylbiferrocene and {Pt(3)}Cl [{Pt(3)} = Pt(3)(mu-PBu(2)(t))(3)(CO)(2)] (1:2 molar ratio) in diethylamine gives in high yields the bicluster derivative [{Pt(3)I}CC-(eta(5)-C(5)H(4))Fe(eta(5)-C(5)H(4))](2), 3, in which two platinum triangles are connected by a diethynylbiferrocene spacer. In the structure of 3, confirmed by a diffractometric study, the two {Pt(3)} fragments lie, perfectly eclipsed, on the same side of the biferrocenyl moiety; this folded structure is also preferred in solution, as suggested by NMR Diffusion Ordered Spectroscopy (DOSY) and 1D Rotating-frame Overhauser Enhancement (ROE) measurements. Compound 3 exhibits a rich redox behavior, with a crowded sequence of six one-electron oxidation processes, the electrode potentials of which have been evaluated by digital simulations. On the basis of a spectroelectrochemical study, the first two oxidations are assigned to the iron centers of the diferrocenyl unit and the subsequent four electrons are removed from the {Pt(3)} units.
Synthesis, Structure and Electrochemistry of the Dicluster Molecular Pincer Pt3(mu-PBut2)3(CO)22(mu-1’,1’’’-diethynylbiferrocene)
LEONI, PIERO;MARCHETTI, LORELLA;BALZANO, FEDERICA;UCCELLO BARRETTA, GLORIA;
2010-01-01
Abstract
The CuI catalyzed dehydro-halogenation of 1',1'"-diethynylbiferrocene and {Pt(3)}Cl [{Pt(3)} = Pt(3)(mu-PBu(2)(t))(3)(CO)(2)] (1:2 molar ratio) in diethylamine gives in high yields the bicluster derivative [{Pt(3)I}CC-(eta(5)-C(5)H(4))Fe(eta(5)-C(5)H(4))](2), 3, in which two platinum triangles are connected by a diethynylbiferrocene spacer. In the structure of 3, confirmed by a diffractometric study, the two {Pt(3)} fragments lie, perfectly eclipsed, on the same side of the biferrocenyl moiety; this folded structure is also preferred in solution, as suggested by NMR Diffusion Ordered Spectroscopy (DOSY) and 1D Rotating-frame Overhauser Enhancement (ROE) measurements. Compound 3 exhibits a rich redox behavior, with a crowded sequence of six one-electron oxidation processes, the electrode potentials of which have been evaluated by digital simulations. On the basis of a spectroelectrochemical study, the first two oxidations are assigned to the iron centers of the diferrocenyl unit and the subsequent four electrons are removed from the {Pt(3)} units.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
