Synthesis and properties of N-substituted maleimides conjugated with 1,4-phenylene or 2,5-thienylene polymers

Abstract

π-Conjugated polymers are particularly interesting in the field of electro-optic materials because of their desirable properties such as electrical conductivity, nonlinear optics and electroluminescence. Coupling polymerizations of 2,3-dibromo-N-substituted maleimide (DBrRMI) (Rbenzyl, phenyl, cyclohexyl, n-hexyl and n-dodecyl) were carried out using palladium or nickel catalysts. The number-average molecular weights of poly(RMI-alt-Ph) obtained by Suzuki-Miyaura cross-coupling polymerizations of DBrRMI with benzene-1,4-boronic acid or 2,5-thiophene diboronic acid were 680-1270 by gel permeation chromatographic analyses. By contrast, Yamamoto coupling polymerizations of DBrRMI with diiodobenzene gave random poly(RMI-co-Ph) results. Poly(RMI-co-Ph)s exhibited a higher thermal stability than monomer and poly(RMI-alt-Ph). Copolymers showed strong photoluminescence from yellow to light blue colors in tetrahydrofuran. © The Society of Polymer Science, Japan (SPSJ) All rights reserved.