Synthesis and Emergent Photophysical Properties of Diketopyrrolopyrrole-Based Supramolecular Self-Assembly

Abstract

Diketopyrrolopyrrole (DPP)-based molecular semiconductors exhibit intriguing optical and charge transport properties. Herein, we rationally design a series of electronically identical but structurally distinct Hamilton receptor (HR)-based supramolecular assembly of DPP. The HR endows supramolecular assemblies via hydrogen bonding with enhanced structural ordering and excitonic couplings. The mechanism of supramolecular self-assembly was probed by diffusion ordered spectroscopy (DOSY) nuclear magnetic resonance (NMR) and solid-state IR spectroscopy studies. We investigated the morphology of self-assembly, photophysical and electrochemical properties and compared them with the identical DPP molecular structures without HRs. The microstructure of self-assembly was probed with atomic force microscopy in thin films. Subsequently, the influence of solid-state packing was studied by single-crystal X-ray diffraction. The single-crystal structure of HR-TDPP-C 20 reveals slipped stack arrangements between the two neighboring chromophores with π–π stacking distance and slip angle of 3.55 Å and 35.4°, respectively. Notably, the slight torsional angle of 1° between thiophene and lactam rings and small π–π stacking distance suggest a significant intermolecular coupling between thiophene (D) and lactam (A) rings. This intramolecular coupling between two π–π chromophore stacks manifests in their optical properties. In this manuscript, we report rational design and synthesis of supramolecular self-assembly of DPP with a collection of compelling structural and optical properties.

Supramolecular Self-Assembly of Diketopyrrolopyrrole with Unprecedented Photoconductivity

“…The molecular backbone comprises the DPP core, planar thiophene, and twisted phenyl π-bridge covalently linked to the Hamilton receptors. The energy-optimized structure reveals the torsion angle of 31° between phenyl to DPP core and Hamilton receptors . The synthesis, characterization, and growth of the supramolecular self-assembly mechanism are discussed elsewhere .…”

“…The synthesis procedure was reported in our published work. 53 5.2. Protocol for FP-TRMC, and XRD Sample Preparation.…”

“…53 The synthesis, characterization, and growth of the supramolecular self-assembly mechanism are discussed elsewhere. 53 The single-crystal XRD structure of HR-TDPP-C 20 suggests that the intermolecular hydrogen bonding and π−π interactions are orthogonal directions to each other (Figure S1). The van der Waal interactions of the self-assembled structure were optimized by introducing different alkyl chains into the orthogonal position of the DPP core, as shown in Figure 1.…”

Boosting CO2-to-CO evolution using a bimetallic diketopyrrolopyrrole tethered rhenium bipyridine catalyst

“…DPP is amenable to π–π stacking and hydrogen-bonding, 48–50 making it an ideal motif to explore physisorption of DPP-based catalysts onto graphitic surfaces. Carbon-based hybrid electrodes were initially made using the bimetallic molecular catalyst ( 2 ) because the observed TOF was twice as large compared to the monometallic complexes in DMF solution ( vida supra ).…”

“…DPP is amenable to π-π stacking and hydrogen-bonding, [48][49][50] making it an ideal motif to explore physisorption of DPP-…”