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71.
72.
smail
zdemir Yetkin Gk Nevin Gürbüz Engin etinkaya Bekir etinkaya 《Journal of heterocyclic chemistry》2005,42(2):303-306
The in situ prepared three component system Pd(OAc)2, 1,3‐dialkylbenzimidazolium halides ( 1a‐e ) and t‐BuOK catalyses quantitatively the Suzuki cross‐coupling of deactivated aryl chloride substrates. 1,3‐Dialkylbenzimidazolium salts ( 1a‐e ) were characterized by conventional spectroscopic methods and elemental analyses. 相似文献
73.
Using a rigid xanthene scaffold, a series of boradiazaindacene derivatives were synthesized. In some of these compounds, two boradiazaindacene derivatives were placed cofacially, resulting in significant inter-chromophoric interactions, including excimer emission. A simple modification of boradiazaindacene structure leads to formation of an ICT dye, which has distinct spectral properties. Energy transfer between two BODIPY dyes was demonstrated as well. In addition, the spectral properties of ICT dye can be modulated by the addition of the acid leading to an acid switchable energy transfer cassette. 相似文献
74.
[reaction: see text] Acylcyclopropanemethanol tosylates undergo rapid ring opening at room temperature by the action of lithium telluride to produce the enolate of a homoallylic ketone. The enolate can be protonated to yield the corresponding ketone or treated with benzaldehyde to give the aldol product with good syn or anti diastereoselectivity depending on the conditions. 相似文献
75.
Neslihan Saki Engin U. Akkaya 《Journal of inclusion phenomena and macrocyclic chemistry》2005,53(3-4):269-273
A novel dimeric calixpyrrole has been synthesized. The dimer forms stable complexes with p-nitrophenolate ion with a concomitant reduction in extinction coefficient. The chromogenic anion is displaced by the addition of various anions like fluoride and acetate. Effective optical sensing of these anions is accomplished using the calixpyrrole dimer. 相似文献
76.
Ismail Özdemir Nevin Gürbüz Yetkin Gök Bekir Çetinkaya Engin Çetinkaya 《Transition Metal Chemistry》2005,30(3):367-371
Six rhodium–carbene complexes (2a–f) have been prepared and the new compounds characterized by C, H, N analyses, 1H-n.m.r. and 13C-n.m.r. Phenylboronic acid reacts with aldehydes in the presence of a catalytic amount of rhodium(I)–carbene complex, RhCl(COD)(1,3-dialkylbenzimidazolidin-2-ylidene), (2a–f), to give the corresponding aryl secondary alcohols in good yields. 相似文献
77.
A novel distyryl-substituted boradiazaindacene (BODIPY) dye displays interesting properties as a sensitizer in DSSC systems, opening the way to further exploration of structure-efficiency correlation within this class of dyes. 相似文献
78.
Performance of a fast fiber based UV/Vis multiwavelength detector for the analytical ultracentrifuge
Holger M. Strauss Engin Karabudak Saroj Bhattacharyya Andreas Kretzschmar Wendel Wohlleben Helmut Cölfen 《Colloid and polymer science》2008,286(2):121-128
The optical setup and the performance of a prototype UV/Vis multiwavelength analytical ultracentrifuge (MWL-AUC) is described
and compared to the commercially available Optima XL-A from Beckman Coulter. Slight modifications have been made to the optical
path of the MWL-AUC. With respect to wavelength accuracy and radial resolution, the new MWL-AUC is found to be comparable
to the existing XL-A. Absorbance accuracy is dependent on the light intensity available at the detection wavelength as well
as the intrinsic noise of the data. Measurements from single flashes of light are more noisy for the MWL-AUC, potentially
due to the absence of flash-to-flash normalization in the current design. However, the possibility of both wavelength and
scan averaging can compensate for this and still give much faster scan rates than the XL-A. Some further improvements of the
existing design are suggested based on these findings. 相似文献
79.
The probabilities for vacancy transfer from the K to the L shell (ηKL), have been calculated for eleven high atomic number elements using the measured K and L shells X-ray production cross-sections. The targets were excited by 123.6 keV photon from a 57Co annular radioactive source. K and L X-rays emitted by samples were counted with a Si(Li) detector. The measured values of ηKL were compared with the theoretical values and our early papers. 相似文献
80.
Backes C Karabudak E Schmidt CD Hauke F Hirsch A Wohlleben W 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(44):13176-13184
We report on the extensive characterization of single-walled carbon nanotubes (SWCNTs) dispersed in a variety of surfactants, such as sodium dodecyl benzene sulfonate (SDBS), sodium cholate (SC), and three synthesized perylene-based surfactants, by using differential sedimentation in H(2)O and D(2)O. Multidimensional evaluation of the absorption profiles over radius, wavelength, and time allows the determination of the anhydrous specific volumes of the SWCNT-surfactant complexes as well as the concentration of the surfactant reservoir in free micelles with very slow sedimentation coefficients (<1 Svedberg). Among the perylene bisimide surfactants, the smallest derivative is densely adsorbed on the nanotube backbone with an anhydrous specific volume significantly above that of SC or SDBS. Bulky Newkome dendritic groups on one or both ends of the perylene moiety gradually reduce the adsorption density, in accord with the absolute adsorption between 0.66 and 1.7 mmol surfactant per gram SWCNTs. Furthermore, hydrodynamic analysis reveals that SDBS favors the "tails-on" configuration. The distribution of sedimentation coefficients of SWCNTs prepared by high-pressure carbon monoxide decomposition (HiPco) is broader and shifted to faster sedimentation than those prepared by using cobalt-molybdenum catalysis (CoMoCAT), which reflects the polydispersity in diameter and length. 相似文献