Theoretical Calculations for Highly Selective Direct Heteroarylation Polymerization: New Nitrile-Substituted Dithienyl-Diketopyrrolopyrrole-Based Polymers

Synthesis and Optoelectronic Properties of New Methoxy-Substituted Diketopyrrolopyrrole Polymers

The introduction of functional groups with varying electron-donating/-withdrawing properties at the β-position of diketopyrrolopyrrole (DPP) has been shown to affect the optoelectronic properties of the polymers. We report the synthesis of a new diketopyrrolopyrrole monomer wherein a strong electron-donating substituent, a methoxy group, was incorporated at the β-position in an effort to modulate polymer properties. Homopolymers and co-polymers of the new β-methoxy DPP and nonderivatized DPP were synthesized, and their properties were measured by cyclic voltammetry and UV-vis-near-infrared. Density functional theory computations also were employed to predict the degree of planarity of β-methoxy oligomers to probe the significance of the newly introduced S-O conformational lock. The combined experimental and computational results showed a reduction in the gap between highest occupied molecular orbital/lowest unoccupied molecular orbital levels, a redshift toward the near-infrared region, and an increased planarity in the β-methoxy polymers.

Novel Diketopyrrolopyrrole-Based π-Conjugated Molecules Synthesized Via One-Pot Direct Arylation Reaction

Diketopyrrolopyrrole (DPP) is an important type of π-conjugated building block for high-performance organic electronic materials. DPP-based conjugated materials are usually synthesized via Suzuki, Stille, or Negishi cross-coupling reactions, which require organometallic precursors. In this paper, a series of novel phenyl-cored DPP molecules, including five meta-phenyl-cored molecules and four para-phenyl-cored molecules, have been synthesized in moderate to good yields, in a facile manner, through the Pd-catalyzed direct arylation of C–H bonds, and their optoelectrical properties have been investigated in detail. All new molecules have been fully characterized by NMR, MALDI-TOF MS, elemental analysis, UV–visible spectroscopy, and cyclic voltammetry. This synthetic strategy has evident advantages of atom- and step-economy and low cost, compared with traditional cross-coupling reactions.