Curing reactions in acetylene-terminated resins. Part 5.—Cyclotrimerization versus linear polyene formation in the catalysed cure of ethynylaryl-terminated monomers

Abstract

Structural differences in the polymers obtained by catalysed cure of the ethynylaryl-terminated monomer [1,4-(1,3-HCCC₆H₄CH₂O)C₆H₄]₂CMe₂(1) could not be detected by IR or NMR spectroscopy. However, a study of the solvent-free catalysed polymerization of the model monomer, phenylacetylene, showed that the extent of cyclotrimerization decreased in the order (η-Cp)Co(CO)₂≫(η-Cp)₂Ni≈(PPh₃)₂NiCl₂≫(PPh₃)₂PdCl₂ with an accompanying increase in the degree of linear polyene formation, suggesting that this is so also for the catalysed cure of 1.