Benzodithiophenes

More recently, OFETs were made with a dimer of another condensed molecule. dithieno[3,2-/j 2, 3 -c/ lhiophene 100, which presents a very similar structure lo that of benzodithiophene, except that the central benzene ring is changed lo a... 

An ab initio study using the 6-31G basis set was used to investigate the vibrational and electronic structures of a benzodithiophene and benzodifuran quinone as potential redox switches. The calculated and experimental data were... 

Gas-phase photoelectron spectroscopy (PES) has been used in conjunction with theoretical calculations to investigate the hole-vibrational and electron-vibrational couplings in fused benzodithiophenes. The first ionization energies of benzojl,2- 5,4- ]dithiophene 21 and benzo[l,2-A4,5- ]dithiophene 22 were found to be to be 7.585 and 7.573eV, respectively <2006CEJ2073>. 

Raman and near-visible IR spectroscopy has been used to characterize the radical cation of the bis-TTF 4 <1997PCB3665, 1997SM(86)1999>. FTIR has been used to confirm ab initio calculations for the radical cation of benzodithiophene 23 and benzodifuran 24. The bisthiophene was found to adsorb at lower wavelengths than the bisfuran <2000JEC24>. 

Iron(iii) chloride has been used as an oxidant to catalyze the cyclization of acyclic precursors to highly derivatized benzodithiophenes <2006TL1551>. Thus, thiophene-based polycyclic aromatics have been produced in high yield (Equation 75). 

Bis(phenylethynyl)-2,2 -bithiophene derivatives function as 1,6-diyne synthons for benzodithiophenes <1997HCA111>. Hence, treatment of 164 with chlorotris(triphenylphosphine)rhodium(l) provides an unstable... 

Benzodithiophene exhibits orange fluorescence in the solid state and a blue emission when irradiated in diluted solution with UV light (98JA2206). A HOMO-LUMO gap of 2.8 eV in dilute chloroform solution was observed from the absorption edge (440 nm), and 2.3 eV energy gap was obtained from the emission peak (547 nm) of a thin film. 

A p-type organic semiconductor 461 based on benzodithiophene building blocks which has exceptional thermal stability was reported (97AM36). The highest mobility ( aFFt = 0.04 cm2 V-1 s-1) was obtained for transistors prepared at Tsub = 100°C because of the accompanying changes in morphology at elevated temperatures. 

In the synthesis of 29 [78], axially chiral precursor was obtained via biaryl coupling between benzodithiophenes with chiral oxazoline [derived from (S)-valinol] as an auxiliary, e.g. Stille cross-coupling of 25 and 26 provided bis(benzodithio-phene) 27 in 68% yield with 49% de (Fig. 15.10). Although the diastereomers were not separable by silica gel column chromatography, crystallization of diastereomers from hexane-ethyl acetate gave crystals with an S-axial configuration. 

A CNDO study on benzo[l,2-c 4,5-c ]dithiophene predicted that it would be more polar than thieno[3,4-c]thiophene, and that excess electron density would be distributed at the bridgehead carbon atoms. A singlet ground state was also predicted <75ACR139>. The heats of atomization, charge densities, and resonance energies of a series of benzodithiophenes were calculated <80T27il>. A [c] fusion led to less resonance stabilization of a system than a [b] fusion. 

The carbocyclic ring in dihydrobenzodipyrazoles, benzodithiophenes, and benzodipyrroles may be aromatized by palladium on carbon <84IJC(B)918,87JOC1521,91H(32)4l>. 

Few reactions of this type are reported, but benzobis-l,2,3-trithioles are oxidized to the 2-oxides (44) by MCPBA (93TL673). Similarly, some tetrahydrobenzodithiophenes are oxidized to S,S -dioxides with periodate. Dehydration of these over alumina afforded aromatic conjugated systems such as the benzodithiophene (11) <84JOC1027>. 

Halogens on a benzodithiophene quinone analogue can be metallated by lithium. The resulting lithio compounds react with borate esters, eventually allowing conversion to the unhalogenated system <83CL905>. 

Spirobisoxiranes (47), formed from benzodithiophene quinones, rearrange to dialdehydes (48) by treatment with lithium bromide (Equation (2)) <88JHC1917>. 

The nature of vibronic coupling in fused polycyclic benzene-thiophene structures, including benzodithiophene 45, naphthodithiophene 111, and anthradithiophene 112, has been studied using an approach that combines high-resolution gas-phase photoelectron spectroscopy measurements with first-principles quantum-mechanical calculations <2006CEJ2073>. 

Ruthenium vinylidene 826 derived from terminal alkyne 825 with RuChl -cymenelPPhs undergoes 6rt-electro-cyclization to afford benzothiophene 827 (Scheme 125) <1996JA11319>. Pt-catalyzed double cyclization of diynes 828 gives polycyclic benzodithiophenes 829 <2005TL8153>. 

Benzodithiophenes 840 are synthesized by In-catalyzed annulation of 2,2 -bithiophenes 839 with methyl propargyl ether (Scheme 128) <2005AGE1336>. 

Benzodithiophene 31 was synthesized as a potential new drug against HIV infection, exploiting the DNA damaging profile of this intercalating substance <2001SC2997>. 

Synthesis of ultrapure, processable, and high-mobility organic transistor semiconductors (thiophene oligomers, anthradithiophenes, benzodithiophenes, phtalocyanins, polythiophenes) 01ACR359. 

J.G. Laquindanum et al., Benzodithiophene rings as semiconductor building blocks, Adv. 

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