Direct arylation polymerization (DArP) has gained interest in the field of materials chemistry as a method to simplify the formation of C-C bonds along conjugated polymer backbones with minimal use of harsh reagents, reaction conditions, and additional purifications. However, traditional direct arylation conditions do not readily yield ideal polymerization characteristics including chain-growth and low dispersities. It would be of great utility to advance DArP methodology to become competitive with traditional conjugated polymerization techniques. In this work, we have developed conditions for a dual-catalytic Ag-Pd system for the synthesis of poly(3-hexylthiophene) (P3HT) that exhibits chain-growth kinetics, low dispersities, and catalyst chain association by Pd. Specifically, the presence of Ag-carboxylate additives plays a beneficial role in the polymerization as a C-H activating agent, while PEPPSI-iPr is used as the Pd source for C-C coupling. The addition of pyridine was found to be necessary to inhibit Pd-mediated C-H activation in the interest of catalyst orthogonality, which can lower dispersities.

Dual-catalytic systems to achieve controlled polymerizations using direct arylation for the synthesis of semiconducting polymers

256th National Meeting (2018)

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