Trifluoromethylation of Anthraquinones for n-Type Organic Semiconductors in Field Effect Transistors

Quantitative Prediction of Charge Mobilities and Theoretical Insight into the Regulation of Site-Specific Trifluoromethylethynyl Substitution to Electronic and Charge Transport Properties of 9,10-Anthraquinone

Herein, we systematically studied the electronic and conducting properties of 9,10-anthraquinone (AQ) and its derivatives and discussed the substitute-site effects on their organic field-effect transistor (OFET) properties in detail. Our calculation results show the influence of different substitute sites on the ionization potential (IP), electronic affinity (EA), reorganization energy (λ), electronic couplings (V), and anisotropic mobility (μ) of semiconducting materials, which mainly originates from the variations of the frontier molecular orbital charge distributions, the steric hindrance, and the conjugate degree. Combining quantum-chemical calculations with charge transfer theory, we simulated the intermolecular hopping rate in the organic crystals of AQ derivatives and predicted the fluctuation range of three-dimensional (3D) anisotropic charge carrier mobility for the first time. Our calculation results well reproduced the experimental observations and provided evidence for the determination of the optimal OFET conduction plane and channel direction relative to the crystal axis.

Amphipolar, Amphiphilic 2,4-diarylpyrano[2,3-b]indoles as Turn-ON Luminophores in Acidic and Basic Media

A versatile amphiphilic pyrano[2,3-b]indole for halochromic turn-ON luminescence in acidic or basic media is accessed by an insertion-coupling-cycloisomerization and adjusting solubilizing and phenolic functionalities. While almost non-emissive in neutral solutions, treatment with acids or bases like trifluoroacetic acid (TFA) or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) reveals distinct luminescence at wavelengths of 540 nm or 630 nm in propan-2-ol, respectively. Turn-ON emission can be detected at pH values as mild as pH = 5.31 or 8.70. Quantum yields in propan-2-ol are substantial for protonated (Φf = 0.058) and deprotonated (Φf = 0.059) species. Photometrically, pKa1 of 3.5 and pKa2 of 10.5 were determined in propan-2-ol. With lipophilic polyether sidechains and hydrophilic protonation and deprotonation sites the molecule can be regarded as amphipolar, which results in good solubility properties for different organic solvents. In aqueous media, an organic co-solvent like propan-2-ol (35%) or tetrahydrofuran (25%) is needed, and the solution can be diluted with pure water without precipitation of the compound. At higher concentrations of water, a turbid solution is formed, which indicates the formation of micellar structures or clusters. With dynamic light scattering we could show that these clusters increase in size with increasing water content.

New Avenues in Copper-Mediated Trifluoromethylation Reactions Using Fluoroform as the CF3 Source

Organic molecules containing the trifluoromethyl (CF3) group play a vital role in pharmaceuticals, agrochemicals, and materials. New trifluoromethylation methods should encompass capabilities to address issues in efficiency, selectivity, and CF3 source all at once. Fluoroform (CF3H), an industrial byproduct, has emerged as an attractive CF3 source. The reaction profile of the [CuCF3] reagent derived from fluo­roform has surpassed its original applications in cross-coupling-type trifluoromethylation. We have discovered a host of unique copper-mediated trifluoromethylation reactions using [CuCF3] from fluoroform, especially under oxidative conditions, to deliver efficient and selective synthesis of trifluoromethylated compounds.

1 Introduction

2 Construction of C–CF3 Bonds for the Synthesis of Trifluoromethylated Building Blocks

2.1 C(sp)–CF3 Bond Formation

2.2 C(sp2)–CF3 Bond Formation

2.3 C(sp3)–CF3 Bond Formation

3 Domino Synthesis of Trifluoromethylated Heterocycles

3.1 3-(Trifluoromethyl)indoles

3.2 3-(Trifluoromethyl)benzofurans

3.3 2-(Trifluoromethyl)indoles

4 Trifluoromethylative Difunctionalization of Arynes

4.1 Trifluoromethylation–Allylation of Arynes

4.2 1,2-Bis(trifluoromethylation) of Arynes

5 Pentafluoroethylation of Unactivated Alkenes

6 Conclusion

Synthesis and photophysical properties of donor-substituted phenyl-phosphachromones as potential TADF materials

A series of novel arylamine-substituted phenyl-phosphachromones were constructed via post-functionalization.