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901.
Sunil Choudhary Cristian Gozalvez Alexander Higelin Prof. Ingo Krossing Prof. Manuel Melle‐Franco Prof. Aurelio Mateo‐Alonso 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(6):1525-1528
A synthetic strategy that allows the induction of twist angles of different sizes in 5,6,11,12,17,18‐hexaazatrinaphthylene (HATNA) chromophores is reported. The different twist angles are accompanied by measurable changes in the emission and electrochemical characteristics of HATNA. 相似文献
902.
Cristian Gómez-Canela Francesc Ventura Josep Caixach Silvia Lacorte 《Analytical and bioanalytical chemistry》2014,406(16):3801-3814
The occurrence of 26 commonly used cytostatic compounds in wastewaters was evaluated using an automated solid-phase extraction (SPE) method with liquid chromatography–high-resolution mass spectrometry (LC–HRMS). Detection was optimized using Oasis HLB SPE cartridges at pH 2. Two hospital effluents and their two receiving wastewater treatment plants were sampled over five days. In hospital effluents, eight cytostatics were detected at levels up to 86.2 μg L?1 for ifosfamide, 4.72 μg L?1 for cyclophosphamide, and 0.73 μg L?1 for irinotecan, the three most relevant compounds identified. Cyclophosphamide and megestrol acetate were found in wastewaters at concentrations up to 0.22 μg L?1 for the latter. The predicted environmental concentrations (PEC) in sewage effluents of ifosfamide (2.4–4.3 ng L?1), capecitabine (11.5–14.2 ng L?1), and irinotecan (0.4–0.6 ng L?1), calculated from consumption data in each hospital, published excretion values for the target compounds, and wastewater elimination rates, were in agreement with experimental values. 相似文献
903.
Cristian Paz Robles Darío Mercado Sebastin Suarez Ricardo Baggio 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(12):1112-1115
A cocrystal, C15H22O3·C15H22O3, (I), obtained from Drimys winteri, is composed of two isomeric drimane sesquiterpene lactones, namely valdiviolide, (Ia), and 11‐epivaldiviolide, (Ib), neither of which has been reported in the crystal form. Both diastereoisomers present three chiral centres at sites 5, 10 and 11, with an SSR sequence in (Ia) and an SSS sequence in (Ib). O—H...O hydrogen bonds bind molecules into chains running along [20] and the chains are in turn linked by π–π stacking interactions to define planar weakly interacting arrays parallel to (001). 相似文献
904.
Cristian Paz Robles Natalia Badilla Vidal Sebastin Suarez Ricardo Baggio 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(11):1075-1078
The natural compound hobartine {systematic name: (1R)‐3‐[(1S,5S)‐(4,4,8‐trimethylbicyclo[3.3.1]non‐7‐en‐2‐yl)methyl]‐2,3‐dihydro‐1H‐indole}, C20H26N2, (I), is an indole alkaloid isolated from Aristotelia chilensis as part of a study of secondary metabolites from Chilean flora. The colourless compound has a tetracyclic structure closely related to the strongly coloured polymorphic structures discussed in Paz et al. [Acta Cryst. (2013), C 69 , 1509–1512] and Watson et al. [Acta Cryst. (1989), C 45 , 1322–1324]. The main differences reside in the absence of a keto group in (I) compared with the previous structures, as well as an endo double bond in (I) contrasting with the exo double bond found in the previous structures. The supramolecular structure of (I) in strongly related to the twofold screw axis, around which isolated chains build up, internally linked by an N—H...N hydrogen bond which is the only significant intermolecular interaction present in the structure. 相似文献
905.
Cyclic gamma-silyloxy-beta-hydroxy-alpha-diazoesters undergo efficient rupture of the Cbeta-Cgamma bond when treated with tin tetrachloride to provide tethered aldehyde ynoate products in high yield. 相似文献
906.
Rhenium carbonyl compounds with (diphenyl)phosphinoalkynes and a sterically hindered phosphinoalkyne
The synthesis and characterization of two series of rhenium carbonyl complexes with P-coordinated phosphinoalkynes are reported. The anionic fac-[ReBr2(CO)3(Ph2PCCR)]− and neutral fac-[ReBr(CO)3(Ph2PCCR)2] (R = Ph, Tol, tBu) complexes have been prepared and the crystal structures of fac-[ReBr2(CO)3(Ph2PCCTol)]− and fac-[ReBr(CO)3(Ph2PCCtBu)2] have been determined by X-ray crystallography, evidencing the presence of the uncoordinated alkyne in all these compounds. The phosphinoalkyne (o-Tol)2PCCPh with bulky groups linked to the phosphorus atom was prepared in order to avoid the coordination of two phosphinoalkynes in cis-position around the rhenium metal. As a result, surprisingly the complex fac-[ReBr(CO)3{(o-Tol)2PCCPh}2] was obtained. The crystal structure of this compound was determined confirming the cis-coordination of two bulky phosphinoalkynes in an octahedral rhenium atom. The electronic properties of the uncoordinated alkyne in these new rhenium complexes was analyzed, based on 13C NMR data and was compared with reported data on iron complexes. The results obtained indicate that the electronic characteristics of uncoordinated alkynes are similar in both families of complexes. Thus, the different reactivity observed between rhenium and iron complexes is related to the different nature of metallic fragments rather than to electronic features of uncoordinated alkynes. 相似文献
907.
Hessel Cristian Perini Nickson Sitta Elton 《Journal of Solid State Electrochemistry》2023,27(3):705-714
Journal of Solid State Electrochemistry - The cadmium sulfide (CdS) is one of the most applied chalcogenides to the water splitting (WS) on photoelectrochemical cells (PEC). The CdS bandgap is... 相似文献
908.
In recent years, 3D printing of carbon-based conductive filaments has received growing attention for assembling electrodes to be used in a wide variety of electroanalytical devices and applications. Despite the large amount of work present in literature concerning the development of three-dimensional (3D) conductive structures, its potential as dry deposition method for assembling two-dimensional (2D) electrodes to be used in planar configuration is still largely unexplored. In fact, the possibility to rapidly change the geometry of the electrochemical circuits, associated with the reduction of waste and the absence of solvents, which are instead important components of ink and paste formulations, makes this strategy a valid green and efficient alternative to other deposition approaches such as screen-printing technology. We report here a rapid and solvent-free method for assembling fully 3D printed flexible planar electroanalytical platforms (3DEPs) to be used with microliters of liquid. At the same time, a novel protocol for the surface pre-treatment of 3D printed electrodes based on ultrasonication in aqueous NaOH solution followed by electrochemical activation using the same medium, is presented. In addition, the same procedure has proved to be efficient for cleaning the electrode surface after electrochemical passivation, thus confirming the validity of both time-efficient and environmentally-friendly assembling and activation/cleaning procedures developed which allow efficient and reusable electrodes to be produced. Finally, 3DEPs were tested by a proof-of-concept quantification of a commonly used food dye (Brilliant Blue, E-133) in commercial solutions used for homemade food coloring. 相似文献
909.
910.
Chemoselective transfer hydrogenation to nitroarenes mediated by cubane-type Mo3S4 cluster catalysts
Sorribes I Wienhöfer G Vicent C Junge K Llusar R Beller M 《Angewandte Chemie (International ed. in English)》2012,51(31):7794-7798
Chemoselective cubes: Cubane-type [Mo(3)S(4)X(3)(dmpe)(3)](+) clusters (dmpe = 1,2-(bis)dimethylphosphinoethane), in combination with an azeotropic 5:2 mixture of HCOOH and NEt(3) as the reducing agent, act as selective cluster catalysts (X = H) or precatalysts (X = Cl) for the transfer hydrogenation of functionalized nitroarenes, without the formation of hazardous hydroxylamines. 相似文献