1. Karpov Institute of Physical Chemistry, Vorontsovo pole 10, Moscow 103064, Russia
2. Efremov Synthetic Rubber Plant, Stroitelei St. 2, Efremov, Tula Region 301860, Russia
3. Current address: Syntezkautschuk Company, Ltd., Myasnitskaya Street, 20, Moscow 101851, Russia.
4. Synthetic Rubber Research Institute, Gapsalskaya St. 1, St. Petersburg 198035, Russia