نتایج جستجو برای: thiophene

تعداد نتایج: 3061  

2002
Sara Y. Yu Javier Garcia-Martinez Wei Li George D. Meitzner Enrique Iglesia

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 H2 on H-ZSM5 and Co/H-ZSM5. Infrared spectra showed that thiophene interacts with acidic OH groups in H-ZSM5 via hydrogen bonding a...

Journal: :The Journal of organic chemistry 2009
William S Jenks Melanie J Heying Stacey A Stoffregen Erin M Rockafellow

Photolysis of derivatives of dimethylmalonate thiophene-S,C-ylide provides dicarbomethoxycarbene, which can react with thiophene to form dimethyl (2-thienyl)malonate. By generation of dicarbomethoxycarbene from the dibenzothiophene-based ylide in neat thiophene, it is shown that the thienylmalonate is not a product of rearrangement of the thiophene ylide, in contrast to thermolysis results. For...

2005
Antonio Chica Karl G. Strohmaier Enrique Iglesia

The adsorption and desorption of thiophene and the reactions of thiophene-derived adsorbed species in He, H2, and O2 were examined on H-ZSM5, H-Beta, and H-Y with varying Si/Al ratios. Thiophene adsorption uptakes (per Al) were independent of Al content, but were above unity and influenced by zeolite structure (1.7, 2.2, and 2.9 on H-ZSM5, H-Beta, and H-Y). These data indicate that thiophene ol...

Journal: :Langmuir : the ACS journal of surfaces and colloids 2004
Antonio Chica Karl Strohmaier Enrique Iglesia

The dynamics and stoichiometry of thiophene adsorption and of rearrangements of thiophene-derived adsorbed species in O(2), He, H(2), and C(3)H(8) carriers were measured using chromatographic methods and mass spectrometry on H-ZSM5 and H-Y zeolites. Thiophene adsorption obeyed Langmuir isotherms on both zeolites. Adsorption uptakes were 1.7 and 2.8 thiophene/Al at 363 K on H-ZSM5 and H-Y zeolit...

2001
Robert A. Welch

We have examined the bonding and orientation of thiophene on Mo(100) following chemisorption at 180 K. At these temperatures, thiophene adsorbs predominantly molecularly, and a shift in the binding energy of peaks due to molecular a-orbitals in the photoelectron spectrum suggests that at least part of the bonding of the thiophene molecule to the surface involves these orbitals. Measurements of ...

Journal: :Dalton transactions 2012
Alessandro Abbotto Carmine Coluccini Elisa Dell'Orto Norberto Manfredi Vanira Trifiletti Matteo M Salamone Riccardo Ruffo Maurizio Acciarri Alessia Colombo Claudia Dragonetti Stefania Ordanini Dominique Roberto Adriana Valore

The first examples of thiocyanate-free thiophene-substituted Ru(II) cyclometalated complexes, based on thiophene-derived 2-(2,4-difluorophenyl)pyridine ligands, are presented and investigated as photosensitizers in DSCs. Upon thiophene substitution the complexes presented enhanced optical properties compared to the reference dye with no thiophene substitution. DSCs based on the dithienyl-derive...

Gholamhossein Shirvani Mohsen Javaheri Nader Saemian,

N-(7-chloro-1-methyl-2-oxo-5-phenyl-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl)thiophene-2 carboxamide-[14C-carboxy] was prepared as part of a 6-step sequence from thiophene-2-carbonitrile -[cyano-14C] as a keysynthetic intermediate which has been synthesized from 2-iodothiophene and zinc [14C]-cyanide in thepresence of tetrakis (triphenylphosphine) palladium.

Journal: :Organic & biomolecular chemistry 2014
Matteo Atzori Flavia Pop Thomas Cauchy Maria Laura Mercuri Narcis Avarvari

2,5-Bis(thiophene) and 2,5-bis(ethylenedioxy-thiophene) (EDOT) derivatives of 3,6-diethoxy-1,4-benzoquinone (para isomers) were prepared by Stille coupling between the 2,5-dibromo-3,6-diethoxy-1,4-benzoquinone precursors and (n-Bu)3Sn-R (R = 2-thiophenyl or 3,4-ethylenedioxy-2-thiophenyl) reagents. In a parallel series of experiments 2,6-bis(thiophene) and 2,6-EDOT-3,5-diethoxy-1,4-benzoquinone...

Journal: :Organic & biomolecular chemistry 2011
Soumyajit Das Anjan Bedi G Rama Krishna C Malla Reddy Sanjio S Zade

Selenophene and thiophene capped cyclopenta[c]selenophenes were synthesized and characterized. Crystal structure determination of some representative compounds revealed that the substitution at 3,4-position in the form of cyclopentane ring of selenophene or thiophene does not make any significant twist in the trimer backbone, making the cooligomer nearly planar. All the cooligomers were electro...

2001
Wei Li Sara Y. Yu Enrique Iglesia

Reaction pathways for the desulfurization of thiophene using alkanes as hydrogen sources were probed by measuring the chemical and isotopic composition of products formed from 13C-labeled C3H8 and unlabeled C4H4S mixtures on H-ZSM5 and Co/H-ZSM5. Aliphatic hydrocarbons formed only from propane carbon atoms while aromatic molecules contained carbon atoms from both propane and thiophene. Hydrogen...

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