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101.
Selective formation of thecis isomer of the nitridotechnetium(V) complex with 2,2′:6′,2″-terpyridine
T. Takayama S. Oshikiri T. Sekine H. Kudo 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(2):397-400
The reaction of [TcNCl2(PPh3)2] with 2,2′:6′,2″-terpyridine producedcis-[TcNCl2(terpy)] selectively. The resulting complexes were characterized by1H NMR and IR spectroscopy. The geometries of thecis andtrans isomers were estimated by theoretical calculations following a density functional method. Thecis isomer is likely more stable than thetrans one with respect to thetrans influence of the nitrido ligand. Furthermore, the behavior of nitridotechnetium complexes in polar solvents was compared
to Os-analogues. 相似文献
102.
103.
Shigehisa Endoh Yoshikazu Kuga Hitoshi Ohya Chihiro Ikeda Hiroyuki Iwata 《Particle & Particle Systems Characterization》1998,15(3):145-149
This study was conducted to establish a simple method for evaluating the morphology of fine anisometric particles using size measurement techniques. The size distributions of mica particles and carbon fibers classified into narrower size ranges were measured by gravitational sedimentation and laser diffraction techniques. The ratio of mean diameters determined for flaky particles strongly depended on the aspect ratio, i.e. flatness. The relationship between particle shape and diameter is discussed theoretically. The experimental results were similar to those predicted. The flatness of fine particles can be evaluated by the ratio of the median diameter determined by laser diffraction to that determined by sedimentation. 相似文献
104.
Tsukano C Okuno M Takemoto Y 《Angewandte Chemie (International ed. in English)》2012,51(11):2763-2766
Quite select: a new strategy was developed for the synthesis of various oxindoles from carbamoyl chlorides. Under the optimum reaction conditions, with Ad(2)PBu as a ligand, tBuCONHOH as an additive, and a CO atmosphere, selective C(sp(3))-H activation proceeded in the presence of a C(sp(2))-H bond. Ad=adamantyl. 相似文献
105.
M Kamitani M Itazaki C Tamiya H Nakazawa 《Journal of the American Chemical Society》2012,134(29):11932-11935
The first catalytic double hydrophosphination of alkynes was achieved by reaction with diarylphosphines in the presence of an iron catalyst. The double hydrophosphination proceeded regioselectively and effectively for various secondary arylphosphines and terminal alkynes to give 1,2-bisphosphinoethane derivatives. 相似文献
106.
Cheng DF Urata C Masheder B Hozumi A 《Journal of the American Chemical Society》2012,134(24):10191-10199
Seamless control of resistance to liquid drop movement for polar (water) and nonpolar alkane (n-hexadecane, n-dodecane, and n-decane) probe liquids on substrate surfaces was successfully demonstrated using molten linear poly(dimethylsiloxane) (PDMS) brush films with a range of different molecular weights (MWs). The ease of movement of liquid drops critically depended on polymer chain mobility as it relates to both polymer MW and solvent swelling on these chemically- and topographically identical surfaces. Our brush films therefore displayed lower resistances to liquid drop movement with decreasing polymer MW and surface tension of probe liquid as measured by contact angle (CA) hysteresis and tilt angle measurements. Subsequently, while mobility of water drops was inferior and became worse at higher MWs, n-decane drops were found to experience little resistance to movement on these polymer brush films. Calculating CA hysteresis as Δθ(cos) = cos θ(R) - cos θ(A) (θ(A) and θ(R) are the advancing and receding CAs, respectively) rather than the standard Δθ = θ(A) - θ(R) was found to be advantageous for estimation of the actual dynamic dewetting behavior of various probe liquids on an inclined substrate. 相似文献
107.
Kamada K Hara C Ogawa K Ohta K Kobuke Y 《Chemical communications (Cambridge, England)》2012,48(64):7988-7990
The two-photon absorption properties of a self-organized dimer of a free-base and zinc(II) porphyrins tandem linked with an ethynylene group and terminated by imidazolyl and phenylethynyl groups were investigated. The self-organized dimer was found to exhibit strong two-photon absorption and furthermore the saturation of the two-photon absorption owing to the intense transition. 相似文献
108.
Uchida T Sekine Y Matsui T Ikeda-Saito M Ishimori K 《Chemical communications (Cambridge, England)》2012,48(53):6741-6743
HutZ, one of the crucial proteins of the iron uptake system in Vibrio cholerae, was purified, which binds to heme at a stoichiometry of 1 : 1. In the presence of ascorbic acid, the HutZ-bound heme degrades via the same intermediates observed in heme oxygenase, suggesting that HutZ works as a heme degradation enzyme. 相似文献
109.
Bahng HW Kim P Sung YM Maeda C Osuka A Kim D 《Chemical communications (Cambridge, England)》2012,48(35):4181-4183
It has been demonstrated that the direction and magnitude of transition dipole moments, and hence rates in the excitation energy hopping in the self-assembled porphyrin boxes can be tuned by insertion of ethynyl groups as well as the dielectric constant of solvent. 相似文献
110.
Escribano-Cuesta A Pérez-Galán P Herrero-Gómez E Sekine M Braga AA Maseras F Echavarren AM 《Organic & biomolecular chemistry》2012,10(30):6105-6111
1,6-Enynes with electron-donating substituents at the alkyne undergo gold(I)-catalysed single cleavage skeletal rearrangement, whereas substrates with electron-withdrawing substituents evolve selectively to double cleavage rearrangement. Theoretical calculations provide a qualitative rationale for these effects, and suggest that bicyclo[3.2.0]hept-5-enes are involved as intermediates. We provide the first X-ray structural evidence for the formation of a product of this class in a cycloisomerisation of a 1,6-enyne. 相似文献