Anthracene- and Thiophene-Containing MEH-PPE-PPVs: Synthesis and Study of the Effect of the Aromatic Ring Position on the Photophysical and Electrochemical Properties
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Wild, Andreas; Egbe, Daniel A. M.; Birckner, Eckhard; Cimrova, Vera; Baumann, Reinhard R.; Grummt, Ulrich-Walter; Schubert, Ulrich S.
- Abstract:
- This contribution reports on the synthesis and characterization of thiophene-
(P1, P2, and P3) and anthracene- (P4 and P5) containing PPE-PPV copolymers.
The thermostable, soluble and film-forming polymers were fully characterized
by NMR, IR and ELEM. ANAL.; they exhibit high molar masses with polydispersity
indices below 2.5. The position of the thiophene in the polymeric backbone has insignificant
influence on the spectroscopic properties of the polymers. In contrast, the
anthracene-containing polymers reveal position dependent optical properties. A constant
bathochromic shift of 50 nm was observed going from P4, where anthracene is
surrounded by two double bonds, to P5, where anthracene is at the bridge between a
triple bond and a double bond, as well as from P5 to P6 where anthracene is surrounded
by two triple bonds. This correlates to the decrease of the observed anthracene
band around 255 nm going from P4 through P5 to P6, amounting to the degree
of contribution of the anthracene unit to the main chain conjugation. The phenomenon
known as CN-PPV effect was observed in the case of P4 [Uf (solution) ¼ 3%,
Uf (solid) ¼ 13%]. Electrochemical studies carried out under absolute inert conditions
revealed lower electrochemical band gap energies, Eec
g , than Eopt
g .
- Year:
- 2009
- Type of Publication:
- Article
- Keywords:
- bandgap; conjugated polymers; electrochemistry; fluorescence; UV vis
- Journal:
- Journal of Polymer Science: Part A: Polymer Chemistry
- Volume:
- 42
- Pages:
- 2243 - 2261