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101.
The total synthesis of (±)-11a-methano- 9,11-thiathromboxane A2(1), the sulfur analog of thromboxane A2 is described 相似文献
102.
Masakatsu Saeki Masami Nakada Nobuyuki M. Masaki Zenko Yoshida Kazutoyo Endo Yoshitaka Minai Toshiyuki Yamashita Hiroshi Mutoh Masaaki Magara 《Hyperfine Interactions》1994,92(1):1177-1181
Experiments on the57Fe Mössbauer effect in frozen solutions were carried out in order to demonstrate the capabilities of a cryostat which was developed for the emission Mössbauer spectroscopy of237Np. We confirmed the existence of an aliovalent state of57Fe in the temperature range from 5.5 to 35 K. However, the relative amounts of Fe(II) and Fe(III) in the frozen matrix were almost constant for the temperature range from 5.5 to 150 K. The design, operation and capabilities of the cryostat are also described. 相似文献
103.
Photocatalytic synthesis of ammonia from water and nitrogen was performed. Binary wafered catalysts prepared with semiconductor powder (TiO2, SrTiO3, CdS or GaP) and platinum black, where the copolymer of ethylene and vinylalcohol was used as a binder, were found to be more effective to yield ammonia than the semiconductor powders alone. 相似文献
104.
Mikio Yagi Nobuyuki Nishi Minoru Kinoshita Saburo Nagakura 《Chemical physics letters》1976,39(2):240-244
Using microwave induced delayed phosphorescence techniques we determined the populating and depopulating rate constants for the individual spin-sublevels of the phosphorescent states of tetracyanobenzene (TCNB) and its charge-transfer complexes with benzene and hexamethylbenzene (HMB) in n-hexane at 1.25 K. It was shown that the non-radiative decay process from the shortest lifetime sublevel is most responsible for the previously observed shortening in the phosphorescence lifetime of the TCNBHMB complex. 相似文献
105.
Thiocarbonyl ylide was found to be generated by thermolysis of bromo(trimethylsilylmethylthio)methyltrimethylsilane and its 1,3-cyclo-addition provided a new method for synthesis of tetrahydrothiophenes. 相似文献
106.
Masahiro Kawasaki Kazuo Kasatani Hiroyasu Sato Hisanori Shinohara Nobuyuki Nishi 《Chemical physics》1984,88(1):135-142
Molecular beams of halogenated hydrocarbons containing chlorine and bromine atoms were photodissociated using an excimer laser at 193 nm. Molecules photodissociated were HCCBr, HCCCH2Br, HCCCH2Cl, CH3Cl, C2H5Cl and i-C3H7Cl. The time-of-flight distributions of the photofragments were measured in order to study the primary processes and the dissociation dynamics. Generalizations consistent with the data are that atomic products (RX → R + X) result from direct dissociation of the CX repulsive singlet state, molecular elimination (RX → R′ + HX) is a result of a crossover to the ground state and triplet states are involved in the photodissociation of alkyne compounds. 相似文献
107.
108.
109.
LiCl acts as a highly effective catalyst for cyanosilylation of various aldehydes and ketones to the corresponding silylated cyanohydrins. The reaction proceeds smoothly with a substrate/catalyst molar ratio of 100-100,000 at 20-25 degrees C under solvent-free conditions. alpha,beta-Unsaturated aldehydes are completely converted to the 1,2-adducts. The cyanation products can be isolated by direct distillation of the reaction mixture. 相似文献
110.
[Structure: see text]. Molecular devices incorporating azobenzene units represent active components of smart systems, as they are capable of exhibiting photoregulated cooperative molecular motion. Herein, we describe the synthesis, X-ray crystal analysis, and photochemical and thermal studies of a xanthene based cyclic azobenzene dimer and its precursor. The trans-trans isomer of the azobenzene dimer upon photoirradiation transforms to the cis-cis isomer through an intermediate trans-cis isomer. The X-ray crystal structures of the trans-trans isomer (open) and the cis-cis isomer (closed) provide unambiguous proof for the hinge-like molecular motion in this class of molecules. The inferences drawn from photochemical and thermal studies shed light on the effect of varied substitution and cyclic structures on the different transitions. The lifetime of the cis-cis isomer is estimated to be 6.43 years, whereas the trans-cis isomer is short-lived (2.73 min) at 303 K. A rational explanation for the relative stability of the different isomers is derived from the isokinetic plot and theoretical calculations. 相似文献