The structure around lithium counterions in polyacrylate solutions has been investigated by neutron diffraction, and it is concluded that small cations remain hydrated when they accumulate around a highly charged polymer. Interactions between the polyion and the counterions over a range outside the hydration shell are also observed. The relaxation rate of 7Li due to dipolar coupling to 17 0 was obtained by nuclear magnetic resonance. The results indicate that the polyion exerts a moderate influence on the reorientational dynamics of the lithium aqua-ion.

Macromolecules 1990,23, 959-963 959 tion product between them. However, it may be said that this catalyst system is very different from the usual Kaminsky-Sinn catalysts composed of MA0 and Cp,TiCl, etc., which effectively catalyze olefin polymerization.As is well-known, heterogeneous catalyst systems usually give polymers having molecular mass distributions with a broad polydi~persity.~ However, the polydispersity of syndiotactic polystyrene obtained with the present heterogeneous catalysts was very narrow, indicating that these catalysts contain not multiple but single, equivalent active species.In conclusion, we have prepared a new supported Kaminsky-Sinn catalyst useful for the syndiotactic polymerization of styrene.A more detailed study is now being carried out, mainly to clarify the nature of active species in the present catalyst system, and the precise results will be published in another paper. References and Notes(1) Ishihara, N.; Seimiya, T.; Kuramoto, M.; Uoi, M. Macromol-(2) Sinn, H.; Kaminsky, W.; Vollmer, H.-J.; Woldt, R.ABSTRACT: The relaxation rates of D and 1 7 0 and the rate of H due to dipolar coupling to " 0 were obtained in a series of poly(acry1ic acid) solutions completely neutralized with lithium and cesium hydroxide. From these data the intramolecular 0-H bond distance and quadrupole coupling constants have been derived. It is found that the changes in 0-H bond distance and quadrupolar coupling constants induced by the charged polymer and its counterions are moderate.