The polymn. of isobutene [115-11-7] with VOCl3 in heptane was investigated. In contrast to reports in the literature, the polymn. only started upon irradn. with light or when naphthalene [91-20-3] was added, and it ceased when the light source was switched off. The reaction proceeded like a photoinitiated cationic polymn., and the claim of a living system was not corroborated.