Studies of poly(3,4-ethylenedioxythiophene) (PEDOT) films containing cationic Mn porphyrins. A loading-dependent demetalation of Mn(III)TPP in PEDOT (Mn(III)TPP=5,10,15,20-tetraphenylporphyrinato manganese(III))

Authors

Danijel Boskovic, University of Wollongong
Sivakumar Balakrishnan, CSIRO, University of Wollongong
Jun Chen, University of WollongongFollow
Pawel W. Wagner, University of WollongongFollow
Gerhard F. Swiegers, University of WollongongFollow

RIS ID

111804

Publication Details

Boskovic, D., Balakrishnan, S., Chen, J., Wagner, P. & Swiegers, G. F. (2016). Studies of poly(3,4-ethylenedioxythiophene) (PEDOT) films containing cationic Mn porphyrins. A loading-dependent demetalation of Mn(III)TPP in PEDOT (Mn(III)TPP=5,10,15,20-tetraphenylporphyrinato manganese(III)). Journal of Porphyrins and Phthalocyanines, 20 (12), 1463-1476.

Abstract

Thin films of vapor-phase polymerized PEDOT incorporating various cationic Mn porphyrins were assessed for water oxidation catalysis under light illumination. Only Mn(III)TPP/PEDOT displayed a notable photocurrent and this was, counter-intuitively, greatest at the lowest loading levels examined. Studies revealed that a proportion of the Mn(III)TPP within the PEDOT became demetalated during polymerization, leaving free and protonated TPP. Despite the presence of an excess of chemical oxidant during the polymerization step, the Mn(III) ion was reduced - likely under the influence of light - to Mn(II), which was labilized out of the film. Whereas PEDOT films loaded with anionic Mn porphyrins may be active and selective water oxidation photocatalysts, their analogs containing cationic Mn porphyrins, like Mn(III)TPP, are catalytically inert.