|Title||Direct heteroarylation polymerization: guidelines for defect-free conjugated polymers.|
|Publication Type||Journal Article|
|Year of Publication||2017|
|Authors||Bura, Thomas, Serge Beaupré, Marc-André Légaré, Jesse Quinn, Etienne Rochette, Terence J Blaskovits, Frédéric-Georges Fontaine, Agnieszka Pron, Yuning Li, and Mario Leclerc|
|Date Published||2017 May 01|
Direct (hetero)arylation polymerization (DHAP) has emerged as a valuable and atom-economical alternative to traditional cross-coupling methods for the synthesis of low-cost and efficient conjugated polymers for organic electronics. However, when applied to the synthesis of certain (hetero)arene-based materials, a lack of C-H bond selectivity has been observed. To prevent such undesirable side-reactions, we report the design and synthesis of new, bulky, phosphine-based ligands that significantly enhance selectivity of the DHAP process for both halogenated and non-halogenated electron-rich and electron-deficient thiophene-based comonomers. To better understand the selectivity issues, density functional theory (DFT) calculations have been performed on various halogenated and non-halogenated electron-rich and electron-deficient thiophene-based comonomers. Calculations showed that the presence of bromine atoms decreases the energy of activation () of the adjacent C-H bonds, allowing undesirable β-defects for some brominated aromatic units. Both calculations and the new ligands should lead to the rational design of monomers and methods for the preparation of defect-free conjugated polymers from DHAP.
|Alternate Journal||Chem Sci|
|PubMed Central ID||PMC5578375|