Preparation of a-Quater-, a-Sexi-, and a-Octithiophenes

Nakayama, Juzo; Konishi, Toru; Murabayashi, Shigeru; Hoshino, Minoru

doi:10.3987/r-1987-07-1793

Cited by 84 publications

(23 citation statements)

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“…Fluorad FC 134 was obtained from 3M Company (St. Paul, MN, USA). Tetrahydrohexaoxapentacene (tridioxin, 3DIO ), α ‐sexithiophene ( α ‐6T),25,26 ET3T (Fig. 1) and tetrahydrooctaoxaheptacene ( 4DIO ) were synthesized in our laboratory (manuscripts in preparation).…”

Section: Methodsmentioning

confidence: 99%

Polymer‐assisted laser desorption/ionization analysis of small molecular weight compounds

Woldegiorgis¹,

Kieseritzky²,

Dahlstedt³

et al. 2004

Rapid Comm Mass Spectrometry

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The use of non-polar, small polymers as matrices for the analysis of low molecular weight compounds in polymer-assisted laser desorption/ionization mass spectrometry (PALDI-MS) is demonstrated. The matrices evaluated were either based on an oligothiophene or a benzodioxin backbone. Metallocenes, polycyclic hydrocarbons, a fluorosurfactant, and a subset of small organic compounds with various functionalities, served as model analytes. The mechanism of ionization charge transfer is discussed and ionization potentials for the matrices in the study have been estimated using density functional theory (DFT) calculations. Some of the results are possibly contradictory to the generally accepted limiting conditions for gas-phase charge-transfer reactions. These results are interpreted in the light of energy pooling. Also a new mass calibration procedure for the low-mass region in positive ion mode is presented, and some aspects of the ionization/desorption process leading to radical cations are studied.

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Section: Methodsmentioning

confidence: 99%

Polymer‐assisted laser desorption/ionization analysis of small molecular weight compounds

Woldegiorgis¹,

Kieseritzky²,

Dahlstedt³

et al. 2004

Rapid Comm Mass Spectrometry

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“…Oligomers shift from colorless dimers, to pale yellow trimers, and ultimately to red for larger structures. 28,29 The large amounts of thiophene formed and the color changes observed suggest the formation of oligomeric thiophene species during thiophene adsorption at ambient temperature on H-ZSM5 and Co/H-ZSM5, but not on Na-ZSM5.…”

Section: Temperature Programmed Desorption Of Pre-adsorbed Thiophenementioning

confidence: 99%

Kinetic, infrared, and X-ray absorption studies of adsorption, desorption, and reactions of thiophene on H-ZSM5 and Co/H-ZSM5

García‐Martínez

et al. 2002

Phys. Chem. Chem. Phys.

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Temperature programmed desorption and infrared and X-ray absorption near-edge spectroscopies were used during adsorption and reactions of thiophene in order to probe adsorbed intermediates and catalytic structures responsible for thiophene reactions with propane or H 2 on H-ZSM5 and Co/H-ZSM5. Infrared spectra showed that thiophene interacts with acidic OH groups in H-ZSM5 via hydrogen bonding at ambient temperature. No additional bands were detected on Co/H-ZSM5, suggesting the absence of specific interactions with Co cations. During adsorption at ambient temperatures, infrared bands assigned to CH 2 groups near C=C bonds or Satoms and to S-H species were detected and H-ZSM5 and Co/H-ZSM5 acquired colors typical of thiophene oligomers. Slightly above ambient temperatures, benzene and H 2 S formed from pre-adsorbed thiophene. These results indicate that hydrogen-bonded thiophene undergoes ring opening or oligomerization near ambient temperature on acidic OH groups in H-ZSM5. Some of the adsorbed thiophene (20-50%) interacts weakly with channel walls or with residual Na cations and desorbs unreacted. The remaining adsorbed thiophene desorbs as H 2 S, aromatic hydrocarbons, and organosulfur compounds, such as methylthiophene and benzothiophene, or forms irreversibly adsorbed unsaturated organic deposits. In situ infrared studies during thiophene and thiophene-propane reactions at 773 K on H-ZSM5 and Co/H-ZSM5 showed that surface coverages of thiophene-derived intermediates were low on acidic OH groups and Co cations. Co K-edge X-ray absorption near-edge spectra measured during these reactions confirmed that Co 2+ cations do not reduce or sulfide; their local environment, however, changes slightly, apparently because of interactions of strongly adsorbed species with Co cations. Sulfur K-edge X-ray absorption spectra detected small amounts of organosulfur species, but no inorganic sulfides, after thiophene, thiophene-H 2 , and thiophene-propane reactions, consistent with the observed stability of exchanged cations against reduction and sulfidation. S : Al ratios were less than 0.04 at. on all samples; these amounts represent less than 1% of the S-atoms removed from thiophene as H 2 S during catalytic propane-thiophene reactions.

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“…In search for better solubility and electronic properties, a number of other α,ω-disubstituted sexithiophenes have also been prepared and characterized. The Stille's coupling reaction was chosen as an alternative method of the Ni-catalyzed reaction for the syntheses because of its proven generality and versatility in preparing aromatic polymers with a variety of functional groups …”

Section: Introductionmentioning

confidence: 99%

Synthesis and Electronic Properties of Aldehyde End-Capped Thiophene Oligomers and Other α,ω-Substituted Sexithiophenes

1996

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A series of α,ω-aldehyde end-capped oligomers of thiophene with three, four, five, six, and eight thiophene units have been synthesized using the palladium-catalyzed Stille's coupling reactions. The UV−vis spectral data indicate that these aldehyde end-capped oligomers have longer conjugation lengths as evidenced by the higher λmax values than the corresponding unsubstituted oligothiophenes. The λmax value increases as the number of thiophene units is increased. The intrinsic conductivity of the solution-cast films of the aldehyde end-capped oligothiophenes is generally higher than that of their corresponding unsubstituted counterparts. Other α,ω-substituted sexithiophenes, such as n-dodecanoyl, tert-butyldimethylsilyl, hydroxymethyl, and [(n-butoxyethoxy)ethoxy]methyl sexithiophenes, have also been synthesized. α,ω-Bis([(n-butoxyethoxy)ethoxy]methyl)sexithiophene has a remarkably high solubility in chloroform (1.8 g/L) and a conductivity (1 × 10-6 S/cm) comparable to the unsubstituted sexithiophene.

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Preparation of a-Quater-, a-Sexi-, and a-Octithiophenes

Cited by 84 publications

References 0 publications

Polymer‐assisted laser desorption/ionization analysis of small molecular weight compounds

Polymer‐assisted laser desorption/ionization analysis of small molecular weight compounds

Kinetic, infrared, and X-ray absorption studies of adsorption, desorption, and reactions of thiophene on H-ZSM5 and Co/H-ZSM5

Synthesis and Electronic Properties of Aldehyde End-Capped Thiophene Oligomers and Other α,ω-Substituted Sexithiophenes

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