NEW POLYMERIC MATERIALS - PORPHYRINS ATTACHED TO PREFORMED POLYSTYRENE

Block-copolymers of styrene and vinylpyridine are microheterogeneous m edia where a separation occurs between the polar and the nonpolar phas es. The aim of our work was to encage zinc porphyrin chromophores in t he hydrophobic part of a polymer, polystyrene- block-poly(vinyl-2-pyri dine), in order to obtain a model of charge separation in energy trans fer. For this purpose, various porphyrins were attached to preformed p olystyrene using two different methods: the Friedel-Crafts reaction be tween polystyrene and porphyrins monofunctionalized by an acid chlorid e and the Williamson reaction starting from polystyrene-co-poly(vinyl- 4-benzylchloride) and porphyrin monofunctionalized by a phenol substit uent. The amount of grafted porphyrins was evaluated by visible and NM R spectra and elemental analysis. The grafted porphyrins were then coe vaporated with the block-copolymers to obtain thin films. The location of the porphyrins was determined by electron microscopy and fluoresce nce spectra. The results proved that the process is successful and the se supported materials are under further investigation.