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A facile synthetic approach to the π-expanded tetrathiafulvalene derivatives is described. The Suzuki reaction of 3,6-dichloropyridazine-fused tetrathiafulvalenes with phenyl boronic acid or biphenyl boronic acid gave a series of novel T-shaped organic π-conjugates. The electronic properties of the conjugates were studied experimentally by the combination of cyclic voltammetry and UV-vis spectroscopy. Their HOMO and LUMO energy levels are estimated to be about -5 eV and -3.2 eV, which are the air operating stability ranges in the p-channel and n-channel field effect transistors, respectively. Only one conjugate bearing the longer alkyl chain (n = 1, R = n-C18H37) was verified to self-assemble into lamellar structures in the mesogenic phase and the best measured charge carrier mobility of its thin-film devices was 4.5 × 10(-5) cm(2) V(-1) s(-1).

A series of monopyrrolotetrathiafulvalene-succinamide conjugates and their 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) charge transfer (CT) complexes have been synthesized and investigated as new low-molecular mass organogelators. The gelation capability of these conjugates is highly dependent on the length of the alkyl chain of the terminal amide. Thus, only the short alkyl chain derivatives and could efficiently gelate cyclohexane and methylcyclohexane (MCH). Surprisingly, these gelators react with TCNQ to form stable CT complex gels in both cyclohexane and MCH. The FE-SEM images of the native gels reveal the characteristic gelation morphologies of microporous or fibrous structures, whereas the morphologies of CT complex gels show the fibrillar and globular aggregates in cyclohexane and MCH, respectively. SAXS study of the native gel and the CT complex gel of in cyclohexane suggests that the molecules maintain rectangular and hexagonal columnar molecular packing models in the gel phase, respectively. The native gels undergo a reversible gel-sol phase transition upon exposure to external stimuli, such as temperature and chemical oxidation/reduction. Alternatively, the corresponding CT complex gels exhibit a complicated response to external stimuli. Chemical oxidation by I2 results in the destruction of the gel state. However, neither Fe(3+) nor Cu(2+) can induce the collapse of the gel phase. Interestingly, all the gels show an irreversible gel-sol transition on successively triggering with trifluoroacetic acid and triethylamine. The reformation of the gel from the sol state is achieved just by the addition of water, showing the phase-selective gelation of the solvents from their mixtures with water.

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Key indicators: single-crystal X-ray study; T = 290 K; mean (C-C) = 0.003 Å; R factor = 0.029; wR factor = 0.094; data-to-parameter ratio = 16.5.The asymmetric unit of the title compound, C 12 H 9 NO 2 S 4 , contains one half-molecule with the N, two S amd four C atoms lying on a mirror plane. The molecule exhibits a Vshaped conformation, with a dihedral angle of 87.00 (7) between the benzene and dithiolopyrrole rings. The methyl group was treated as rotationally disordered between two orientations in a 1:1 ratio. In the crystal, weak C-HÁ Á ÁO hydrogen bonds link the molecules into chains in [010]. Related literature ExperimentalCrystal data