Molecular scale organized polyconjugated polymer–heteropolyacid composites

A Kokorin,A Kulak,D Meissner,T Kulak

doi:10.3176/proc.2009.1.02

Abstract

Hybrid organic-inorganic molecular-organized materials based on a conductive polymer - poly(2-metoxy-5- (3',7'-dimethyloctyloxy)-p-phenylenevinylene) (MDMO-PPV) - doped with Keggin-type heteropolyacids (polyoxometalates) were synthesized. It is shown that the rate of chemical interaction between MDMO-PPV and heteropolyacids correlates with the oxidative activity and acidity of the latter and leads to the form ation of tertiary structures due to a strong electrostatic in teraction of each 4-6 monomer units of the polymer with the heteropolyacid anion cluster. This interaction manifests itself in the appearance of an intensive EPR signal characteristic of the unpaired electron localized in the conjugated polymer matrix as wel l as in the changes in optical, photoelectrochemical, and photoluminescence properties of the composite films.

Highlights

Hybrid organic–inorganic molecular-organized materials based on a conductive polymer – poly[2-metoxy-5(3′,7′-dimethyloctyloxy)-p-phenylenevinylene] (MDMO-PPV) – doped with Keggin-type heteropolyacids were synthesized
It is shown that the rate of chemical interaction between MDMO-PPV and heteropolyacids correlates with the oxidative activity and acidity of the latter and leads to the formation of tertiary structures due to a strong electrostatic interaction of each 4–6 monomer units of the polymer with the heteropolyacid anion cluster
The chemical elemental analysis of the organic moiety of the MDMO-PPV–heteropolyacid deposits indicated that MDMO-PPV did not undergo essential chemical transformations in its interaction with polyoxometalates, because the percentages of carbon (78.8%), hydrogen (9.7%), and oxygen (11.5%) in the organic moieties of the composite remained practically the same as in the untreated MDMO-PPV (79.1%, 9.8%, and 11.1%, correspondingly)

Summary

Introduction

Hybrid organic–inorganic molecular-organized materials based on a conductive polymer – poly[2-metoxy-5(3′,7′-dimethyloctyloxy)-p-phenylenevinylene] (MDMO-PPV) – doped with Keggin-type heteropolyacids (polyoxometalates) were synthesized. It is shown that the rate of chemical interaction between MDMO-PPV and heteropolyacids correlates with the oxidative activity and acidity of the latter and leads to the formation of tertiary structures due to a strong electrostatic interaction of each 4–6 monomer units of the polymer with the heteropolyacid anion cluster This interaction manifests itself in the appearance of an intensive EPR signal characteristic of the unpaired electron localized in the conjugated polymer matrix as well as in the changes in optical, photoelectrochemical, and photoluminescence properties of the composite films. Solutions of MDMO-PPV in a concentration of 0.01 mol/L calculated for the monomeric unit and 0.04 mol/L solutions of the heteropolyacid in a methanol–chloroform mixture (1 : 1, by volume) were used for the investigation of the interaction between the

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Conclusion