Synthesis and Optical Study of a New Oligophenylene

• Main Authors: Sadok Roudesli, Kamel Alimi, Eric Faulques, Jany Wéry, Mourad Chemek, Florian Massuyeau, Ayoub Haj Said, Sarra Ben Amor
• Format: Article
• Language: English
• Published: MDPI AG 2012-05-01
• Series: Polymers
• Subjects: conjugated polymers; oligophenylenes; photoluminescence
• Online Access: http://www.mdpi.com/2073-4360/4/2/1226

A new substituted oligophenylene was prepared by the Knoevenagel condensation of 4-methoxybezaldehyde with a functionalized oligophenylene (OMPA). The latter was obtained by (4-methoxy phenyl) acetonitrile electrochemical oxidation.<strong> </strong>The resulting modified oligomer was characterized by various spectroscopic techniques: NMR, FTIR and UV. The thermal study showed that the modified material exhibited a lower thermal stability compared with OMPA. Finally, the optical study revealed that in solution, the emission was red-shifted when compared with the non-modified oligomer emission and that the optical gap changed from 3.1 eV to 2.75 eV. In thin layer solid state, photoluminescence was again red-shifted by 120 nm, which is probably due to an interaction between the oligomer chains. In addition, a transient photoluminescence study was undertaken for the synthesized materials. It showed that the lifetimes of the photo-generated species were shortened by the conjugation extension in the modified oligomer and by the inter-chain interactions in the solid state.