Curing reactions in acetylene-terminated resins. Part 4.—IR and NMR study of catalysed polymerization of aryl prop-2-ynyl etherterminated monomers

Abstract

Partial polymerization of the aryl prop-2-ynyl ether-terminated monomer (pHCCCH₂OC₆H₄)₂CMe₂(1) and complete polymerization of the analogous model monomer pHCCCH₂OC₆H₄CMe₂Ph (2) in the presence of various catalysts afforded soluble polymers, the study of which enabled the effect of catalysts on resin structure to be determined. IR and NMR spectroscopy, in particular the chemical shift of the CH₂O protons, showed: (a)(η-Cp)Co(CO)₂ gives rise exclusively to acetylene cyclotrimerization; (b)(η-Cp)₂Ni and (PPh₃)₂NiCl₂ each result in both cyclotrimerization and non-aromatic polyene formation; (c)(PPh₃)₃RhCl gives linear polymers with backbone branched enyne groups which act as crosslink sites in further polymerization.