title: A novel linkage-isomeric pair of dinuclear Pd(II) complexes bearing a bis-bidentate tetraphos ligand.
abstract: The tetraphosphane all trans tetrakis-(di(2-methoxyphenyl)phosphanyl)cyclobutane) (o-MeO-dppcb) has been employed to coordinate metal dichlorides (metal = Ni(II), Pd(II) and Pt(II)), stereoselectively yielding the dinuclear complexes [Ni(2)Cl(4)(micro-(kappaP(1):kappaP(2):kappaP(3):kappaP(4)-o-MeO-dppcb))] and [Pt(2)Cl(4)(micro-(kappaP(1),kappaP(2):kappaP(3),kappaP(4)-o-MeO-dppcb))], characterized by two six and two five-membered metallacycles, respectively. Conversely, the reaction with PdCl(2) led, under comparable synthetic conditions, to the formation of the linkage-isomeric pair [Pd(2)Cl(4)(micro-(kappaP(1),kappaP(2):kappaP(3),kappaP(4)-o-MeO-dppcb))] and [Pd(2)Cl(4)(micro-(kappaP(1):kappaP(2):kappaP(3):kappaP(4)-o-MeO-dppcb))] in a ca. 4 : 1 ratio. The compounds obtained have been characterized in solution by multinuclear NMR spectroscopy and in the solid state by CP-MAS NMR spectroscopy, XRPD and single crystal X-ray diffraction. Compounds and have been tested as catalyst precursors for the CO-ethene-propene co-and terpolymerization in water-acetic acid mixtures. Their catalytic performance has been compared to that of [PdCl(2)(o-MeO-dppe)] (o-MeO-dppe = 1,2-(bis(di(2-methoxyphenyl)phosphanyl))ethane) and of [PdCl(2)(o-MeO-dppp)] (o-MeO-dppp = 1,3-bis(di(2-methoxyphenyl)phosphanyl)propane). The most striking result that emerged from the CO-ethene copolymerization study was that was three times more productive than , outperforming, under identical catalytic conditions, even 1b and 1c, that are classified amongst the most active catalysts for the CO-ethene copolymerization reaction.
authors.affiliation: Institut für Allgemeine, Anorganische und Theoretische Chemie der Universität Innsbruck, Innrain 52a, 6020 Innsbruck, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Fessler
authors.forename: Georg
authors.initials: G
authors.lastname: Czermak
authors.forename: Sylvia
authors.initials: S
authors.lastname: Eller
authors.forename: Barbara
authors.initials: B
authors.lastname: Trettenbrein
authors.forename: Peter
authors.initials: P
authors.lastname: Brüggeller
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Bettucci
authors.forename: Claudio
authors.initials: C
authors.lastname: Bianchini
authors.forename: Andrea
authors.initials: A
authors.lastname: Meli
authors.forename: Andrea
authors.initials: A
authors.lastname: Ienco
authors.forename: Werner
authors.initials: W
authors.lastname: Oberhauser