Syndiotactic polystyrene clathrates with polar guest molecules

Stable syndiotactic polystyrene (s-PS) co-crystals with highly polar guests have been prepared by sorption in delta or in co-crystalline phases of molecules dissolved in suitable solvent carriers. These co-crystals are clathrates, that is, isolated molecules are imprisoned as a guest into cavities formed between layers of polymer helices, and the maximum guest molecular volume is close to 0.25 nm(3). Infrared linear dichroism measurements show that molecules included in s-PS molecular complexes are oriented nearly perpendicular to the chain axes of the polymeric crystalline phase. These new materials present in their crystalline phases an ordered three-dimensional arrangement of highly polar molecules with large first-order hyperpolarizability.