Synthesis of conjugated polymers. Polymerizability studies of bis-sulfonium salts

Abstract

Although the bis-sulfonium salt precursor route is one of the most versatile procedures available for the synthesis of conjugated polymers, little effort has been made to explore the scope of this polymerization reaction. In this study, a series of bis-sulfonium salts were synthesized and in order to assess their polymerizability, isotopic exchange at the benzylic positions as well as their reactivity was studied by ¹³C-NMR spectroscopy. Meanwhile the generation of the reactive intermediate was analyzed by UV spectroscopy. In addition, the reaction heats of the equilibria leading to the intermediate polymerizable species from the corresponding precursors were calculated by computational methods. The relationship between the chemical structure of the bis-sulfonium salts, their ability to polymerize, and the theoretical results was then analyzed in an effort to establish a reactivity pattern that could help to predict the type of bis-sulfonium salt that can be polymerized by this synthetic route and to contribute to the rational design of new conjugated polymers.

Keywords:

• Conjugated polymers
• poly(arylene vinylene)s
• precursor route
• bis-sulfonium salts