Collect. Czech. Chem. Commun. 2003, 68, 1094-1104

First Examples of Homogeneous Catalytic Cyclotrimerization and Polymerization of Phenylacetylene and Copolymerization of Phenylacetylene and Norbonene with Dinuclear Complexes Containing Unbridged Metal-Metal Quadruple Bond

Konstantinos Mertisa,*, Stavros Arbiliasa, Demos Argyrisa, Nikos Psaroudakisa, Jiří Vohlídalb, Olivier Lavastrec and Pierre H. Dixneufc

a University of Athens, Inorganic Chemistry Laboratory, Panepistimiopolis, 15701 Athens, Greece
b Charles University, Department of Physical and Macromolecular Chemistry, Laboratory of Specialty Polymers, Albertov 2030, CZ-12840 Prague 2, Czech Republic
c Université de Rennes 1, Laboratoire de Chimie de Coordination et Catalyse, 35042 Rennes, France


First examples of application of dinuclear complexes containing unbrigded metal-metal quadruple bond as catalysts in cyclotrimerization, oligomerization and polymerization of substituted acetylene are reported. The d4-d4 dinuclear complexes (Bu4N)2[Re2X8] (1) (1a, X = Cl; 1b, X = Br and 1c, X = I) show low activity and the complex [Mo2Cl4(MeOH)2(PPh3)2] (2) medium activity in cyclotrimerization and oligomerization of phenylacetylene (PA). In contrast, the tungsten-based d4-d4, complex Na4[W2Cl8] (3) exhibits high polymerization activity (polymer yield above 90%) and ca 75% cis-selectivity in tetrahydrofuran. The activity and cis-stereoselectivity of these single-component catalysts decrease in the order 3 >> 2 >> 1, which is proportional to the metal-metal quadruple bond propensity towards ligand addition reactions. Complex 3 induces metathesis polymerization of norbornene (NBE) to poly(cyclopentene-1,3-diylvinylene) with 82% cis-selectivity and copolymerization of PA and NBE to almost all-cis high-molecular-weight copolymer containing cyclopentene-1,3-diylvinylene units, which is free of longer sequences of both PA and NBE units. This suggests that also homopolymerization of PA with 3 proceeds by the metathesis mechanism and that the PA/NBE copolymer structure is close to the alternating one.

Keywords: Cyclotrimerizations; Dinuclear complexes; Metal-metal quadruple bond; Alkenes; Alkynes; ROMP; Metathesis polymerizations; Single-component catalysts; Rhenium; Tungsten; Molybdenum.

References: 47 live references.