A new family of air-stable sulfur-hetero oligoarenes based on the benzo[k]fluoranthene unit has been facilely developed as the active materials for thin film organic field-effect transistors. The Diels-Alder reaction between cyclopentadienone 1 and 2,2'-(ethyne-1,2-diyl)bisthiophene followed by decarbonylation afforded fluoranthene derivative 2. After bromination and subsequent substitution through Suzuki coupling reaction, the FeCl3-oxidative cyclization produced sulfur-hetero benzo[k]fluoranthene derivatives 8-12. In dilute chloroform solution, the absorption and emission behaviors of 2 and 4-7 showed characteristic features of the fluoranthene units, while their emission lambda(max) red-shifted with an increase of the effective conjugation length. The steady state absorption and emission spectra of these newly synthesized compounds were thoroughly investigated and discussed. Thin film organic field-effect transistors (OFETs) using 8-11 as active materials were fabricated in a "top contact" configuration. Substituents at the skeleton play an important role in the film morphologies, which lead to different mobilities, while the charge mobilities of 8-11 from OFETs were improved after thermal annealing of the thin films. A carrier mobility as high as 0.083 cm(2) V(-1) s(-1) and current on/off ratio of 10(6) were achieved through vacuum-deposited film followed by the thermal annealing process from 11.
Facilitated by arene-perfluoroarene interactions, a 1,3-dipolar cycloaddition between azide and alkyne proceeded in the crystals at room temperature in the absence of a copper(I) catalyst, and the reaction was confirmed to be a highly regioselective process giving the 1,4-triazole product.
The cycloaddition of azides and alkynes in the solid state was accelerated by high pressure. In situ Raman scattering and synchrotron X-ray diffraction were employed to study reaction kinetics at different pressures which revealed that the pressure acceleration originates from the elevated substrate energy and decreased activation energy.
We have designed a supramolecular system to pre-organize the azide and alkyne functional groups via electrostatic and arene-perfluoroarene interactions. After pre-organization, high pressure was applied to accelerate the copper-free cycloaddition of the azide and alkyne groups in the crystalline state. † Electronic supplementary information (ESI) available: Experimental details, 1 H NMR, 13 C NMR and 19 F NMR spectra, single crystal data and structure refinement of complexes 1′•2 and 2•3. CCDC reference numbers 874309 and 874310. For ESI and crystallographic data in CIF or other electronic format see
A phenyl and a 2,3,5,6-tetrafluorophenyl ring, each bearing a tris(n-dodecyloxy)benzylamine moiety via an amide bond, were tethered together through an imine linkage to give a non-covalent synthon (imine 1) with a strong capacity of supramolecular self-assembly. Gelation was observed in several organic solutions, within which fibrous aggregate morphologies were visualized by SEM and AFM. Both arene-perfluoroarene stacking and amide-amide hydrogen bonding interactions were responsible for such self-assembly behaviours, as evidenced by 1 H NMR studies. Hydrolysis of the imine linkage catalyzed by acid strongly weakened the intermolecular interactions, resulting in dissociation of the low molecular weight gelator and giving rise to an acid-mediated gel-sol transition.
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