Pd/C as a Clean and Effective Heterogeneous Catalyst for C–C Couplings toward Highly Pure Semiconducting Polymers

Abstract

Conjugated polymers are the primary blocks for organic electronics. Traditionally, conjugated polymers synthesized via Suzuki, Heck, and Stille couplings are catalyzed by soluble homogeneous ligated palladiums, which suffer the contaminations of residual nano-palladium and phosphine impurity resulting from side reaction of aryl−aryl exchange. To overcome these drawbacks, a commercially available, clean, and ligand-free heterogeneous catalyst Pd/C for the C−C coupling polymerizations was developed in this work. The Pd/ C catalyst showed increases in catalytic activity for Suzuki and Heck polymerizations, as compared with the classical homogeneous catalyst Pd(PPh 3 ) 4 . Furthermore, the Pd/C catalyst exhibited advantage of much less Pd residue in the resulting polymers, leading to better charge transport properties as demonstrated by field effect transistors.

Plausible role of nanoparticle contamination in the synthesis and properties of organic electronic materials

“…Mostly acceptable values of 10 -100 ppm are utilized in many other synthetic applications and can also be suggested in organic electronics. As a representative example, the preparation of highly pure semiconducting polymers with a Pd content of only 34 ppm has been described [34].…”

“…A heterogeneous Pd/C catalyst was utilized in the synthesis of thiophene building blocks for organic electronics [39] and for the preparation of highly pure semiconducting polymers [34]. It was found that the supported Pd/C catalyst gives better selectivity and efficiency in the synthesis of desired products in comparison to common Pd catalysts.…”

Organometallic Approaches to Conjugated Polymers for Plastic Solar Cells: From Laboratory Synthesis to Industrial Production

“…[19] Polymerization was performed in a THF/water mixture as solvent, with addition of N-methylpyrrolidinone or dimethylformamide to stabilize the palladium center and with K 2 CO 3 as the base. Both polymers P16 and P17 have diketopyrrolopyrrole as the acceptor unit and carbazole as the donor.…”

Aziridine- and Azetidine-Pd Catalytic Combinations. Synthesis and Evaluation of the Ligand Ring Size Impact on Suzuki-Miyaura Reaction Issues

“…This reaction has become for decades a major methodological tool available to chemists to build molecular architectures especially based on a biaryl scaffold. The biaryl motif can be found in numerous natural products, agrochemicals, drugs, polymers, ligands and thus triggered the attention of the scientific community for a wide range of applications [2][3][4][5][6][7][8][9]. If the formation of a biphenyl motif belongs nowadays to a textbook knowledge, the past decade has witnessed spectacular innovations and improvements such as ligandless transformations [10], supported or nanostructured catalytic systems [11][12][13], performing additives [14,15], neat and/or aqueous conditions [2,13,15], MW activations [10] for example.…”