Spectroscopic investigation of host-guest interactions into clathrate phases of syndiotactic polystyrene containing chlorinated compounds

A Fourier transform infrared spectroscopy investigation relative to clathra te forms of syndiotactic polystyrene (s-PS) with chlorinated organic compou nds is presented. In particular, for 1,2-dichloroethane (DCE), 1,2-dichloro propane (DCP), and 1-chloropropane (CP), the absorption peaks which are mod ified as a result of clathrate formation have been identified and analyzed. The study has shown that in the polymeric clathrate phase, a nearly comple te conformational selectivity occurs for DCE and DCP, while the conformatio nal equilibrium of CP remains substantially unaltered. Both for DCE and DCP , the conformational selectivity is in favor of conformations leading to tr ans chlorine atoms and is associated with specific attractive interactions involving the chlorine atoms. The observation of shifts of C-Cl stretching bands indicates that attractive interactions are possibly established betwe en chlorine atoms and aromatic rings, both in amorphous and in clathrate ph ase of s-PS.