| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1441637 | Synthetic Metals | 2012 | 10 Pages |
Two thiophene monomers: 3-methyltetra(oxyethylene)oxy-4-methylthiophene (MT) and a monomer containing a meso-3,5-ditert-butyl-tetraphenylporphyrin unit linked via a tetra(ethylene glycol) spacer (MTP) were synthesized and characterized. Both monomers were copolymerized in different ratios MT:MTP (2:1 and 4:1), using FeCl3 as oxidizing agent, to give the corresponding copolymers (CTP-1 and CTP-2). MTP was also homopolymerized under the same reaction conditions to give the homopolymer (PTP). The obtained monomers and polymers were characterized by FTIR, 1H and 13C NMR spectroscopies. On the other hand, the optical properties of the polymers were studied by absorption and fluorescence spectroscopy in THF solution. All polymers exhibited the typical absorption bands of the porphyrin units: a Soret band at λ = 422 nm and four Q-bands between λ = 500 and 700 nm, as well as an additional band at λ = 451 nm, due to the polythiophene backbone. PTP, CTP-1 and CTP-2 showed fluorescence in the region between λ = 500 and 800 nm. Finally, the electrochemical properties of MTP and the obtained polymers were studied by cyclic voltammetry. Tetraphenylporphyrin (TPP) was used as model compound for comparative purposes. The obtained electrochemical data revealed the presence of the redox processes due to the porphyrin and the thiophene units. The reactivity of MTP toward electrochemical polymerization was studied.
► Novel polythiophenes containing free-base porphyrin units were synthesized. ► In these polymers, typical absorption bands of the porphyrin units were observed. ► The absorption band for the polythiophene backbone appeared at 451 nm. ► Beside emission at λ = 654 nm and 722 nm, copolymers show another band at 541 nm. ► An oxidation peak is observed at potentials close to that of the thiophene units.
