Thin‐film transistors (TFTs) based on a new n‐channel organic semiconductor (DCMT; see Figure) are reported. An electron mobility as high 0.2 cm 2 /V s was observed, well ambipolar TFT behavior. Variable temperature measurements reveal that conduction is activated, with small activation energy of 35 ± 10 meV. These results demonstrate quinoidal oligothiophenes promising class semiconductors for TFTs.

A terthiophene-based quinodimethane, 3',4'-dibutyl-5,5' '-bis(dicyanomethylene)-5,5' '-dihydro-2,2':5',2' '-terthiophene (1) was synthesized and crystallized. Compound 1 has a planar quinoid geometry that is stabilized by dicyanomethylene groups at each end of the molecule. In crystal molecule part dimerized face-to-face π-stack, with intermolecular spacings 3.47 3.63 Å, respectively. Cyclic voltammetry showed could be reversibly reduced oxidized in methylene chloride solution. Thin film...

Complexes of amorphous tetraglyme (G4) and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) or bis(perfluoroethylsulfonyl)imide (LiBETI) were prepared as pol(yethylene) oxide-type electrolytes. Addition equimolar amounts LiTFSI results in a room temperature ionic liquid with the general formula [Li(G4)]TFSI. Differential scanning calorimetry analysis [Li(G4)]TFSI reveals that it has complex remains over wide range (−100 to 200°C), very low vapor pressure for at temperature. The...

A series of new quinodimethane-substituted terthiophene and quaterthiophene oligomers has been investigated for comparison with a previously studied quinoid oligothiophene that demonstrated high mobilities ambipolar transport behavior in thin-film transistor devices. Each quinoidal thiophene derivative shows reversible one-electron oxidation between 0.85 1.32 V, quasi-reversible second 1.37 1.96 two-electron reduction −0.05 −0.23 V. The solution UV−vis−NIR spectrum each compound is dominated...

Two quinonoid bis(dicyanomethylene) oligothiophenes, terthiophene and quaterthiophene analogues of TCNQ, have been investigated by spectroelectrochemical experiments density functional theory calculations. Electrochemical data show that the molecules can be both reduced oxidized at relatively low potentials, derivative forms four stable redox species, dianion, neutral, cation radical, dication. The neutral oligomers are characterized a strong electronic absorption in red or near-infrared...

A novel series of terthiophenes bearing electron-donor and electron-acceptor groups at the end α-positions has been prepared. The analysis UV−vis, infrared, Raman spectra, performed with aid density functional theory calculations, shows that asymmetrically substituted nitro compounds PhT3NO2 BrT3NO2 behave as push−pull systems present an intense photoinduced charge transfer in visible spectrum. symmetrically dinitro compound NO2T3NO2 displays a highly delocalized structure low single−double...

Two new oligothiophenes, the dinitro compound 3',4'-dibutyl-5,5' '-dinitro-2,2':5',2' '-terthiophene (1) and quinodimethane '-bis(dicyanomethylene)-5,5' '-dihydro-2,2':5',2' (2), have been synthesized studied with electrochemistry, UV-vis-NIR-IR spectroscopy, ESR, X-ray crystallography. These compounds, designed to be both electron hole carriers, show redox properties that are unusual for oligothiophenes. Cyclic voltammetry spectroelectrochemistry demonstrated each could oxidized a cation...

We have synthesized several new push-pull oligothiophenes based on the boron dipyrromethene (BODIPY) moiety as electron acceptor and more well-known substituted with N,N-dialkylamino functions to enhance their electron-donor ability. A complete characterization of electronic properties has been carried out; it consists photophysical, electrochemical, vibrational properties. The compounds studied after chemical treatment acids oxidation. In this regard, they can be termed NIR dyes amphoteric...

Direct addition of tetracyanoethylene to N-(p-hexylphenyl)dithieno[3,2-b:2',3'-d]pyrrole yields not only the aromatic mono- and bis-tricyanovinyl-substituted products but also a quinoidal product with dicyanomethylene groups. The analogous reaction dithieno[3,2-b:2',3'-d]thiophene exclusively mono-tricyanovinyl product. possess red-shifted absorptions, increased electron affinities, favorable pi-stacking motifs in comparison unsubstituted oligomers.

New stilbenoid and thiophenic compounds terminally functionalized with donor–donor, acceptor–acceptor, or donor–acceptor moieties possessing a central [2.2]paracyclophane unit have been prepared, their properties interpreted in terms of through-bond through space π-electron delocalization (i.e., π-conjugations). Based on photophysical data, excited-state described focus the participation competition conjugation side arms. To this end, two-photon one-photon absorption emission spectroscopy,...

Tricyanovinyl-capped oligothiophenes of up to six rings have been synthesized and characterized. The substituted oligomers display dramatic reductions in both their optical electrochemical band gaps comparison unsubstituted oligomers. solvatochromic behavior the terthiophene-substituted molecule was investigated a variety solvents. Stable oxidations were exhibited by sexithiophene-substituted on CV time scale. [structure: see text]

The infrared absorption and Raman scattering spectra recorded during the electrochemical oxidation of two sexithiophenes are reported. Using in situ spectroelectrochemical methods five states, neutral, radical cation, dication, trication, tetracation an α,α'-diphenyl sexithiophene, were studied. experimental agreement with predictions effective conjugation coordinate theory good accordance theoretical density functional calculations.

We report the structural and electrical characterization of thin films organic semiconductor molecules consisting an oligothiophene core capped with electron-withdrawing tricyanovinyl (TCV) groups. X-ray diffraction atomic force microscopy evaporated three different TCV-capped oligothiophenes showed that were highly crystalline. Electrical transport was measured in film transistors employing silver source drain contacts channel probes to correct for contact resistance. Three compounds...

Oligothiophene-substituted 1,1,4,4-tetracyanobutadienes (TCBDs) have been synthesized by [2 + 2] cycloaddition reactions between tetracyanoethylene and oligothiophene alkynes. The TCBD moiety is compared to other electron acceptors attached dibutylterthiophene including dicyanovinyl (DCV) tricyanovinyl (TCV). These donor−acceptor molecules (TCBD-3T, DCV-3T, TCV-3T) show red-shifted absorption spectra relative the unsubstituted as a result of intramolecular charge-transfer (ICT)....

The electronic and the Fourier transform Raman (FT-Raman) spectra of a novel well−barrier−well vinylene-bridged sexithiophene in neutral doped states have been recorded. samples were oxidized chemically, with trifluoroacetic acid or ferric chloride, electrochemically dichloromethane solutions. evolution spectral pattern upon oxidation at different anodic potentials has analyzed for thin solid film material. Experimental observations are explained by initial generation radical cation species...

We analyze the electronic and molecular structures for ground excited states of aromatic terthiophene (3T), quinodimethane 3',4'-dibutyl-5,5' '-bis(dicyanomethylene)-5,5' '-dihydro-2,2':5',2' '-terthiophene (3Q), isologues with middle ring S-oxidized (3TO2, 3QO2). These represent extremes electron rich deficient states, often exhibiting complementary properties. Oxidizing central sulfur atom affects structure, affinity, photophysical properties both pi systems. The consequences 3T include...

A series of eight conjugated oligomers consisting central dithieno[3,2-b:2',3'-d]pyrroles (DTPs) end-capped with either thienyl or phenyl groups have been prepared from N-alkyl-, N-aryl-, and N-acyl-dithieno[3,2-b:2',3'-d]pyrroles via Stille Suzuki cross-coupling. The DTP-based quaterthiophene, N-phenyl-2,6-bis(2-thienyl)dithieno-[3,2-b:2',3'-d]pyrrole was characterized X-ray crystallography found to crystallize in the orthorhombic space group Pna2(1) a = 10.8666(3) Å, b 22.8858(6) c...

A new series of bipyridine-capped oligothiophene ligands and their binuclear Ru(II) complexes the general formula [(bpy)(2)Ru-bpy(th)(x)bpy-Ru(bpy)(2)](4+) (where bpy = 2,2'-bipyridyl, th 2,5-thienyl, x 1, 3, or 6) has been synthesized. Comparison oligothiophenes to corresponding uncapped oligomers shows that there is coupling bipyridine oligothiophene-conjugated pi-system. Each reduces at a cap potentials less negative than those free bipyridine. The lambda(max) values lowest pi-pi*...

Abstract The UV/Vis, infrared absorption, and Raman scattering spectra of 3′,4′‐dibutyl‐5,5″‐bis(dicyanomethylene)‐5,5″‐dihydro‐2,2′:5′,2″‐terthiophene have been analyzed with the aid density functional theory calculations. compound exhibits a quinoid structure in its ground electronic state presents an intramolecular charge transfer from terthiophene moiety to C(CN) 2 groups. molecular system therefore consists electron‐deficient backbone end‐capped electron‐rich molecule is characterized...

In this project, an alternative approach to synthesize ammonia electrochemically from wind energy, nitrogen gas, and ethanol is reported. Initial electrolyses have been attempted using room temperature ionic liquids (RTILs) as the electrolyte solvent in presence of lithium ions. Bis(trifluoromethanesulfonyl)imide salts 1-Ethyl-3-methylimidizolium (EMI-TFSI) 1-Butyl-1-methylpyrrolidinium (PYR14-TFSI) were tested investigation. These results are compared use tetrahydrofuran solvent. The data...

ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTPBC-DFT Applied to Donor−Acceptor Copolymers in Organic Solar Cells: Comparisons between Theoretical Methods and Experimental DataTed M. Pappenfus*, Jennifer A. Schmidt, Ryan E. Koehn, Joseph D. AliaView Author Information Division of Science Mathematics, University Minnesota, Morris, Minnesota 56267, United States*E-mail [email protected]; Fax 320-589-6371; Ph 320-589-6340.Cite this: Macromolecules 2011, 44, 7, 2354–2357Publication Date (Web):March...

[structure: see text] A series of thiophene-based homologues with an aromatic core surrounded by terthiophene "arms" acetylene linkages has been synthesized using Sonogashira coupling methods. The were investigated spectroscopically in solution and the solid state. They display extended pi-conjugation through that affects strong emission redox properties.

A series of tricyanovinyl (TCV)-substituted oligothiophenes was synthesized and investigated with a number physical methods including UV/Vis, IR, Raman spectroscopy, nonlinear optical (NLO) measurements, X-ray diffraction, cyclic voltammetry. Mono- or disubstituted oligomers were prepared by the reaction tetracyanoethylene mono- dilithiated oligomers. The comparative effects symmetric asymmetric substitutions in electronic molecular properties have been addressed. These display dramatic...

Abstract We have prepared a new series of mixed thiophene–pyrrole oligomers to investigate the electronic benefits arising from combination these two heterocycles. The are functionalized with several hexyl and aryl groups improve both processability chemical robustness. An analysis their spectroscopic (absorption emission), photophysical, electrochemical, solid state, vibrational properties is performed in quantum‐chemical calculations. This provides relevant information regarding use...

Abstract This study reports the scalability of direct arylation polymerization (DArP) batch reactions for preparation poly(3‐hexylthiophene) (P3HT) using Herrmann–Beller catalyst combined with a tertiary phosphine in green solvent 2‐methyltetrahydrofuran on scales ranging from 0.5 to 10 g. The physical properties these DArP polymers are compared those resulting P3HT prepared via Grignard metathesis (GRIM) 130 g scale. Both and GRIM methods found produce highly regioregular no evidence...