Organometallic chemistry of homoleptic carbonylmetal cations.: 1.: Stereospecific tetramerization of 2-propynol and polymerization of arylacetylenes by means of [Pt(CO)4][Sb2F11]2

Neat 2-propynol was treated with 7 x 10(-3) mol % of solid [Pt(CO)(4)][Sb2F11](2) (1) in a carbon monoxide atmosphere to afford 2,5-dimethyl-2,5-bis(2-propynoxy)-1,4-dioxane (2) in high yield. The bis-alkyne derivative was converted into its bis(hexacarbonyldicobalt)complex 3 by reaction with 2 equiv of [Co-2(CO)(8)]. Compound 3 was fully characterized by a single-crystal X-ray analysis. In contrast to this, selected arylacetylenes were polymerized by 1 to afford poly(arylacetylenes) with an all-trans transoidal microstructure. With 2.1 x 10(-2) up to 2.7 x 10(-2) mol % of catalyst average molecular weights (M-W) between 3000 and 4300 were obtained.