A sulfur-rich pi-electron acceptor derived from 5,5 '-bithiazolidinylidene: charge-transfer complex vs. charge-transfer salt

International audienceNovel pi-electron acceptors are still highly desirable for the formation of conducting salts or as n-dopable semiconductors. We describe here two synthetic approaches to substitute a dicyanovinylidene group, C=C(CN)(2) to a thioketone (C=S) in the recently described DEBTTT acceptor where DEBTTT stands for (E)-3,3'-diethyl-5,5'-bithiazolidinylidene-2,4,2',4'-tetrathione. These electron withdrawing groups enhance the electron accepting ability as demonstrated through electrochemical investigations, without hindering the formation of short intra-and intermolecular S center dot center dot center dot S contacts in the solid state. Association of this acceptor 1 with tetramethyltetrathiafulvalene (TMTTF) and decamethylferrocene (Fe(Cp*)(2)) afforded 1 : 1 adducts which were analyzed by single crystal X-ray diffraction. Combined with vibrational and magnetic properties, it appears that [TMTTF][1] behaves as a neutral charge-transfer complex while [Fe(Cp*)(2)][1] is an ionic salt. The concentration of the spin density on the exocyclic sulfur atoms in 1(-center dot) favors the setting of direct anti-ferromagnetic interactions in [Fe(Cp*)(2)][1

Opportunities for polymer-based nanowires in optoelectronics and nanophotonics

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Opportunities for polymer-based nanowires in optoelectronics and nanophotonics

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New Trends in Beverage Packaging Systems: A Review

New trends in beverage packaging are focusing on the structure modification of packaging materials and the development of new active and/or intelligent systems, which can interact with the product or its environment, improving the conservation of beverages, such as wine, juice or beer, customer acceptability, and food security. In this paper, the main nutritional and organoleptic degradation processes of beverages, such as oxidative degradation or changes in the aromatic profiles, which influence their color and volatile composition are summarized. Finally, the description of the current situation of beverage packaging materials and new possible, emerging strategies to overcome some of the pending issues are discussed

Acromegaly caused by growth hormone-releasing hormone-producing tumors: long-term observational studies in three patients

We report on three newly diagnosed patients with extracranial ectopic GHRH-associated acromegaly with long-term follow-up after surgery of the primary tumor. One patient with a pancreatic tumor and two parathyroid adenomas was the index case of a large kindred of MEN-I syndrome. The other two patients had a large bronchial carcinoid. The first patient is still in remission now almost 22 years after surgery. In the two other patients GHRH did not normalize completely after surgery and they are now treated with slow-release octreotide. IGF-I normalized in all patients. During medical treatment basal GH secretion remained (slightly) elevated and secretory regularity was decreased in 24 h blood sampling studies. We did not observe development of tachyphylaxis towards the drug or radiological evidence of (growing) metastases. We propose life-long suppressive therapy with somatostatin analogs in cases with persisting elevated serum GHRH concentrations after removal of the primary tumor. Independent parameters of residual disease are elevated basal (nonpulsatile) GH secretion and decreased GH secretory regularity

Structural Conformers of (1,3-Dithiol-2-ylidene)ethanethioamides: The Balance Between Thioamide Rotation and Preservation of Classical Sulfur-Sulfur Hypervalent Bonds

The reaction of N-(2-phthalimidoethyl)-N-alkylisopropylamines and S2Cl2 gave 4-N-(2-phthalimidoethyl)-N-alkylamino-5-chloro-1,2-dithiol-3-thiones that quantitatively cycloadded to dimethyl or diethyl acetylenedicarboxylate to give stable thioacid chlorides, which in turn reacted with one equivalent of aniline or a thiole to give thioanilides or a dithioester. Several compounds of this series showed atropisomers that were studied by a combination of dynamic NMR, simulation of the signals, conformational analysis by DFT methods, and single crystal X-ray diffraction, showing a good correlation between the theoretical calculations, the experimental values of energies, and the preferred conformations in the solid state. The steric hindering of the crowded substitution at the central amine group was found to be the reason for the presence of permanent atropisomers in this series of compounds and the cause of a unique disposition of the thioxo group at close-to-right angles with respect to the plane defined by the 1,3-dithiole ring in the dithiafulvene derivatives, thus breaking the sulfur–sulfur hypervalent bond that is always found in this kind of compounds.Ministerio de Economıá y Competitividad, Spain (Project CTQ2012- 31611), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (Project BU246A12-1), and the European Commission, Seventh Framework Programme (Project SNIFFER FP7-SEC-2012-312411