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491.
492.
Koucký J Kolesniková L Uhlíková T Varga J Kania P Beckers H Willner H Urban Š 《The Journal of chemical physics》2012,136(9):094309
The rotational spectra of the isotopically substituted free fluoroformyloxyl radical FC(18)O(2·) were measured using the Prague millimeter-wave high-resolution spectrometer. More than 110 rotational-fine-hyperfine transition lines were observed and assigned to appropriate quantum numbers in the frequency range of 235-270 GHz. The obtained transition frequencies were analyzed with standard effective Hamiltonians to acquire a set of precise rotational, centrifugal-distortion, fine, and hyperfine structure molecular constants. Merging the new FC(18)O(2·) isotopologue molecular parameters with those previously obtained for the ordinary FC(16)O(2)[middle dot] radical, the substitution molecular geometry in the ground vibronic state was evaluated. The molecular parameters for both radical isotopologues were also calculated by several quantum chemistry methods and their calculated mutual ratios are in remarkable agreement with the experimental FC(16)O(2·)/FC(18)O(2·) parameter ratios. The measurements, assignments of the 18-oxygen isotopologue FC(18)O(2·) radical millimeter-wave transitions, as well as the derivation of the fluoroformyloxyl radical ground-state geometry have been carried out for the first time. 相似文献
493.
Yan-Yan Song Zhida Gao Kiyoung Lee Patrik Schmuki 《Electrochemistry communications》2011,13(11):1217-1220
In the present work, we show how TiO2 nanotube layers that are decorated with a Pt-nanoparticle coating can be fabricated and operated as a reusable glucose sensing system. A critical amount of Pt coating is essential not only to provide an effective catalyst for glucose oxidation but also to establish a sufficient conductivity along TiO2 nanotube walls to allow an efficient amperometric operation of the electrode. On such an electrode the self-cleaning photocatalytic features of TiO2 can be maintained and used to re-establish poisoned activity of the Pt particles. 相似文献
494.
In the present work, we report on the formation of mesoporous thick tungsten trioxide films grown on tungsten foil by anodization in fluoride containing concentrated phosphoric acid (85%) electrolyte. Under optimized experimental conditions, mesoporous WO3 films with a thickness up to approximately 2 μm are formed. SEM shows the films to consist of a connected network with a typical pore and feature diameter of ca 50 nm. These films as formed are amorphous and can be annealed to orthorhombic WO3 structure. These thick porous films can show significant enhanced electrochromic and improved photocatalytic properties. 相似文献
495.
Lucie Benesova Milos Pesek Barbora Belsanova Patrik Sekerka Marek Minarik 《Journal of separation science》2010,33(15):2349-2355
The presence of activating mutations within the tyrosine kinase domain of the epidermal growth factor receptor gene has been attributed to a positive response to biological therapy of lung cancer by small‐molecular tyrosine kinase inhibitors, gefitinib and erlotinib. Among the two most significant mutation types are deletions in exon 19 and a single point substitution in exon 21 (termed L858R). The exon 19 deletions can readily be examined by fragment analysis, due to the characteristic length difference between the normal and mutated PCR product. Analysis of the L858R point mutation, however, presents a greater challenge. The current paper is aimed at developing a sensitive, yet simple, low‐cost mutation detection assay directed at the L858R mutation using a method based on CE of heteroduplexes under partial denaturing conditions. We perform optimization of separation conditions on different commercial instruments including ones equipped with 8, 16 and 96 capillaries. We present normalized migration reproducibility in the range from 1 (8 and 16) to 5% (96) RSD. A reliable distinction of the R836R silent polymorphism from a potential presence of the L858R mutation is also demonstrated. In its implementation, the presented assay is just another application running on a conventional CE platform without the need of dedicated instrumentation. 相似文献
496.
Doohun Kim Poulomi Roy Kiyoung Lee Patrik Schmuki 《Electrochemistry communications》2010,12(4):574-578
In the present work, we produce 15 μm thick titania mesosponge layers (TMSL) by a Ti anodization/etching process and use the layers in dye-sensitized solar cells (DSCs). We show that the solar cell efficiency can considerably be improved by a TiCl4 hydrolysis treatment (increase of approx. 40% to an overall value of 4.9% under AM 1.5 illumination). This beneficial effect is due to the decoration of the ~10 nm wide channels present in TMSL with TiO2 nanoparticles of approx. 3 nm diameter, which allow for a significantly higher specific dye loading of the TMS structure. 相似文献
497.
Li Chen Yinglin Zhou Shihong Jiang Julia Kunze Patrik Schmuki Steffi Krause 《Electrochemistry communications》2010,12(6):758-760
The resolution of photocurrent measurements at field-effect capacitors as used in light-addressable potentiometric sensors (LAPS) and scanning photo-induced impedance microscopy (SPIM) has been investigated using silicon on sapphire (SOS) substrates illuminated at different wavelengths. Using a two-photon effect in silicon (λ = 1250 nm) to generate the photocurrent, genuine submicrometer resolution has been demonstrated for LAPS and SPIM. Improved sensitivity for both LAPS and SPIM was obtained using a 6.7 nm thick gate oxide on SOS anodically grown in 0.1 M HCl. 相似文献
498.
Paul Binger Patrik Müller Petra Philipps Barbara Gabor Richard Mynott Albert T. Herrmann Franz Langhauser Carl Krüger 《欧洲无机化学杂志》1992,125(10):2209-2212
Bis(trimethylphosphane)titanocene ( 1 ) reacts with 2-methylene-1,1-diphenylcyclopropane ( 2 ) to give red crystalline (η2-2-methylene-1,1-diphenylcyclopropane)(trimethylphosphane)titanocene ( 3 ). In solution complex 3 degrades smoothly to form the new Cp2Ti(PMe3) – C2 – Ti(PMe3)Cp2 complex 4 , the crystal structure of which has been elucidated by an X-ray analysis. 相似文献
499.
Xiaoqing Zeng Dr. Helmut Beckers Dr. Helge Willner Prof. Dr. Patrik Neuhaus Dirk Grote Dr. Wolfram Sander Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(48):13466-13473
Triplet difluorophosphoryl nitrene F2P(O)N (X3A′′) was generated on ArF excimer laser irradiation (λ=193 nm) of F2P(O)N3 in solid argon matrix at 16 K, and characterized by its matrix IR, UV/Vis, and EPR spectra, in combination with DFT and CBS‐QB3 calculations. On visible light irradiation (λ>420 nm) at 16 K F2P(O)N reacts with molecular nitrogen and some of the azide is regenerated. UV irradiation (λ=255 nm) of F2P(O)N (X3A′′) induced a Curtius‐type rearrangement, but instead of a 1,3‐fluorine shift, nitrogen migration to give F2PON is proposed to be the first step of the photoisomerization of F2P(O)N into F2PNO (difluoronitrosophosphine). Formation of novel F2PNO was confirmed with 15N‐ and 18O‐enriched isotopomers by IR spectroscopy and DFT calculations. Theoretical calculations predict a rather long P? N bond of 1.922 Å [B3LYP/6‐311+G(3df)] and low bond‐dissociation energy of 76.3 kJ mol?1 (CBS‐QB3) for F2PNO. 相似文献
500.
Traditionally, the choice of acid/base additives used in chiral preparative chromatography has not been considered very important. However, it was recently demonstrated that strongly adsorbing additives can result in the most unexpected enantiomer band shapes in modern chiral preparative chromatographic systems. In the present study we demonstrate that, depending on the choice of additive, it is actually possible to obtain the following four binary band-shape compositions when a racemic mixture is injected: (i) anti-Langmuir/anti-Langmuir, (ii) anti-Langmuir/Langmuir, (iii) Langmuir/Langmuir and (iv) Langmuir/anti-Langmuir. Further, we made an advanced numerical investigation, in order to ascertain which one of the four band-shape compositions, is the most favourable one in preparative batch chromatography of a racemic mixture. We found that if the target for purification is either the first eluting enantiomer or both ones, the traditional Langmuir/Langmuir band-shape composition should be chosen. But, if only the second eluting enantiomer is to be purified the optimal situation is the anti-Langmuir/Langmuir band-shape composition. Thus, it was concluded that the best choice of additive depends on which enantiomer is of interest and it is useful to perform a thorough additive screening to find the optimal additive, giving the most advantageous peak shape composition and accordingly the best process performance for a particular separation problem. 相似文献