Spectroscopic and catalytic studies of selected polyimines protonated with heteropolyacids

Aromatic poly(azomethines), namely unsubstituted polyazomethine (PPI) and ring substituted polyazomethine (PMOPI), prepared from p-phenylenediamine and the appropriate dialdehydes, have been protonated with heteropolyacids (H3PW12O40 and H3PMo12O40) in order to obtain new conjugated polymer supported catalysts. Detailed Raman and FTIR spectroscopic studies of the undoped and doped polymers have been performed. In i-propanol conversion these new catalysts exhibit predominantly redox activity producing acetone with high selectivity. The catalytic results are very similar to those obtained for polyaniline protonated with the same heteropolyacids showing that the insertion of HPA to the polymer matrix via the protonation reaction efficiently blocks their acid-base functions.