Crystalline structure determination of selected polyimines

The crystalline structures of unsubstituted poly(azomethine) (PPI) and metoxy substituted PPI (PMOPI) were determined by X-ray diffraction and computer modelling. Both compounds exhibit relatively high degree of crystallinity (~ 30%). The calculated diffraction patterns (almost identical to the experimental ones) show that the polymers investigated crystallize in a pseudomonoclinic or a triclinic lattice, respectively. The influence of protonation with selected heteropolyacids on the structural properties of both systems was also investigated.