Molecular scale organized poly(MDMO-p-phenylene vinylene)–heteropolyacid composites

In this study, the interaction of phosphomolybdic acid (H3PMo12O40) with poly[2-metoxy-5-(3′,7′-dimethyloctyloxy)-p-phenylene vinylene] (MDMO-PPV) has been investigated by the methods of optical absorbance and luminescence spectroscopy, electrochemical, EPR and chemical analysis. It is shown that the interaction between MDMO-PPV and H3PMo12O40 leads to the formation of charge-transfer complex, which involves one heteropolyanion per four monomer units of the polymer chain. We have demonstrated that this interaction causes reversible changes in the electronic structure of the polymer as well as the appearance of an additional line in a long-wavelength region of optical absorbance spectra, a sharp decrease of the efficiency of luminescence and the emergence of pronounced EPR signal.