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The preparation of a new class of electron deficient organic compounds is of great interest for the development of high‐performance n‐type organic semiconductors. Herein, the facile synthetic protocol for the isolation of the first examples of truxenone triimide (TTI) is reported. The electrochemical analysis of the resulting TTIs confirms that the multi‐imidization helps in lowering the LUMO energy level, tailoring prerequisite optoelectronic and/or semiconducting properties. Their microscopic charge carrier transport properties and dynamics are screened by flash‐photolysis time‐resolved microwave conductivity measurements. Compound 2D exhibited an electron mobility of 0.27 cm2 V−1 s−1 under ambient conditions. [ABSTRACT FROM AUTHOR]

In principle, polymerization tends to produce amorphous or poorly crystalline materials. Efficiently producing high-quality single crystals by polymerization in solvent remains as an unsolved issue in chemistry, especially for covalent organic frameworks (COFs) with highly complex structures. To produce μm-sized single crystals, the growth time is prolonged to >15 days, far away from the requirements in practical applications. Here, we find supercritical CO2 (sc-CO2) accelerates single-crystal polymerization by 10,000,000 folds, and produces two-dimensional (2D) COF single crystals with size up to 0.2 mm within 2~5 min. Although it is the fastest single-crystal polymerization, the growth in sc-CO2 leads to not only the largest crystal size of 2D COFs, but also higher quality with improved photoconductivity performance. This work overcomes traditional concept on low efficiency of single-crystal polymerization, and holds great promise for future applications owing to its efficiency, industrial compatibility, environmental friendliness and universality for different crystalline structures and linkage bonds. Rapid growth of highly crystalline Covalent organic framework (COF) materials remains challenging. Here, the authors accelerate single-crystal polymerization using supercritical CO2 and realize the fabrication of two-dimensional COF single crystals within several minutes. [ABSTRACT FROM AUTHOR]

Abstract: Organogels based on self‐assembled low band gap organic semiconductors are of great interest in the field of optoelectronics, although there are not many such systems known. Herein, we report a diketopyrrolopyrrole derivative (DPP‐Amide) with H‐bonding terminal groups that promote one‐dimensional (1D) assembly. This design leads to the formation of an organogelator having a low band gap of 1.5 eV, and near‐infrared (NIR) emission in the self‐assembled state. Furthermore, in the film state self‐assembled DPP‐Amide showed enhanced intrinsic photoconductivity when compared to isolated molecules upon the addition of different weight ratio of phenyl‐C71‐butyric acid methyl ester (PC71BM). [ABSTRACT FROM AUTHOR]

The formation of coaxial p-n heterojunctions by mesoscale alignment of self-sorted donor and acceptor molecules, important to achieve high photocurrent generation in organic semiconductor-based assemblies, remains a challenging topic. Herein, we show that mixing a p-type π gelator (TTV) with an n-type semiconductor (PBI) results in the formation of self-sorted fibers which are coaxially aligned to form interfacial p-n heterojunctions. UV/Vis absorption spectroscopy, powder X-ray diffraction studies, atomic force microscopy, and Kelvin-probe force microscopy revealed an initial self-sorting at the molecular level and a subsequent mesoscale self-assembly of the resulted supramolecular fibers leading to coaxially aligned p-n heterojunctions. A flash photolysis time-resolved microwave conductivity (FP-TRMC) study revealed a 12-fold enhancement in the anisotropic photoconductivity of TTV/PBI coaxial fibers when compared to the individual assemblies of the donor/acceptor molecules. [ABSTRACT FROM AUTHOR]