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141.
Oshio H Nihei M Koizumi S Shiga T Nojiri H Nakano M Shirakawa N Akatsu M 《Journal of the American Chemical Society》2005,127(13):4568-4569
The tetranuclear complex [MnIII2NiII2Cl2(salpa)2] (salpa = N-(2-hydroxybenzyl)-3-amino-1-propanol) has a spin ground state of S = 6 and was confirmed to be an SMM based on a steplike feature of the magnetization hysteresis loop at 0.55 K. 相似文献
142.
The dynamic and laser characteristics of the self-Q-switched Cr,Yb:YAG laser were studied by solving the coupled rate equations; the effects of the pump rate, reflectivity of the output couplers and the concentrations of the saturable absorbers on the laser performance were investigated in detail and the numerical simulation of the Cr,Yb:YAG lasers was in good agreement with the experimental data. Better laser performance of the Cr,Yb:YAG self-Q-switched laser can be obtained by using high pump rate, higher concentration of the saturable absorber and suitable reflectivity of the output coupler according to our numerical calculations. A typical self-Q-switched laser pulse of 269.5 J pulse energy with 319 ps pulse width (FWHM) at a repetition rate of 3.1 kHz can be obtained with a monolithic laser cavity, which results in 843.5 kW peak power. 相似文献
143.
Electron nuclear double resonance (ENDOR) measurements were performed on stretched films of undoped cis-rich (CH)x at 77°K. The anisotropy of the hyperfine coupling was directly observed for the first time. The anisotropy shows the π-electron character and is consistent with the assumption of the bond alternation kink in the π-electron system in undoped (CH)x. 相似文献
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A simple and rapid simultaneous analytical method of four post-harvest fungicides, o-phenylphenol (OPP), diphenyl (DP), thiabendazole (TBZ), imazalil (IMZ) and its major metabolite R14821 (IMZ-M) in citrus fruits was developed. These compounds were extracted under basic conditions with diethyl ether. The organic layer was washed with water and evaporated at moderate pressure adding methanol. These compounds were determined by liquid chromatography-mass spectrometry (LC-MS) using atmospheric pressure photoionization (APPI). The recoveries of the five compounds added to citrus fruits at 1 microg/g ranged from 67 to 100%, with relative standard deviations (R.S.D.) ranging from 2 to 8%. The detection limits (S/N = 3) were 0.01 microg/g and 0.05 microg/g (DP). 相似文献
148.
Treatment of (E)-alk-1-enyldicyclohexylboranes 1 with diisobutylaluminium hydride (DIBAL-H) in the presence of hex-1-ene at room temperature results in transfer of the alk-1-enyl group from boron to aluminium to give (E)-alk-1-enyldiisobutylalanes 2 with retention of configuration at the double bond. 相似文献
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Gold(I)‐Catalyzed Asymmetric Desymmetrization of meso‐Alkynyl Diols and Kinetic Resolution of the Corresponding dl‐Diols: Effects of Celite Filtration and Silver Salts
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Yumi Sota Masaaki Yamamoto Masato Murai Prof. Dr. Jun'ichi Uenishi Prof. Dr. Motokazu Uemura 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(11):4398-4404
The asymmetric desymmetrization of meso‐2‐alkynylbenzenediols through the use of a combination of axially chiral diphosphine(AuCl)2 precatalysts and silver salt co‐catalysts gave optically active isochromene compounds with high enantioselectivities in good yields. The corresponding dl ‐diol isomers underwent efficient kinetic resolution to give the cyclized isochromenes and recovered diols with high enantioselectivities under similar conditions. The high reactivity and selectivity in the desymmetrization of the meso‐diols is independent of the combination of axially chiral diphosphine(AuCl)2 precatalyst and silver salt co‐catalyst, whereas the corresponding tricarbonylchromium complexes of alkynylbenzenediols were affected by the combination of the diphosphine(AuCl)2 and silver salt. The reactivity was largely dependent on the nature of the gold(I) species. 相似文献