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991.
Benzo[b] thiophene derivatives. XVIII. The sulfur isosteres of harmaline,harmine and related isomers
T. R. Bosin R. P. Maickel A. Dinner A. Snell E. Campaigne 《Journal of heterocyclic chemistry》1972,9(6):1265-1266
The sulfur analogs of harmaline, 7-methoxy-3,4-dihydro-1-methyl[1]benzothieno[2,3-c]-pyridine (Ib), harmine, 7-methoxy-1-methyl[1]benzothieno[2,3- c ]pyridine (IIb), and corresponding 6-methoxy isomers (Ic and IIc) have been synthesized for pharmacological evaluation as monoamine oxidase inhibitors. 相似文献
992.
The results of allowing tetrahydro-as-triazine-3(2H)-thiones to react with various α,β-diiunctional compounds, such as, α-bromoethyl p-toluenesulfonate, chloroacetaldehyde, α-bromophenylacet-uldehyde, phenaeyl bromide, chloroacetonitrile, α-bromophenylaeelonitrile, and α-cyanobenzyl p-toluenesulfonate are discussed. These condensations give either a 5H-thiazolo[3,2-b]-as-triazine or a 2H-thiazolo[2,3-c]-as-triazine. 相似文献
993.
Quantitative measurement of both bulk and localized oxygen concentrations is of importance in the study of oxidation kinetics.
We describe the combined application of two nuclear techniques, fast neutron activation analysis and (d, p) nuclear microprobe,
to the determination of oxygen concentrations and surface profiles for steam-oxidized Zircaloy-4 cladding specimens. Results
of measurements using these techniques are presented.
Work partially supported by Electric Power Research Institute Contract T.S.A. No. 20. 相似文献
994.
Studies on Alkyl Metal Alkoxides of Aluminium, Gallium, and Indium. III. Properties and Vibrational Spectra of Dialkylgallium- and Indium Alkoxides The preparation and the properties of dialkyl metal alkoxides R2MOR′ (with R = CH3, CD3, C2H5; R′ = CH3, CD3 and M = Ga, In) are described. The vibrational data (IR and Raman) of the trimeric methyl derivatives point to puckered six-membered M3O3-ring systems. 相似文献
995.
A rapid, sensitive and selective method for the determination of carbamazepine and its major metabolite in plasma has been developed. Other commonly used anticonvulsants can be determined in the same procedure without interference. After extraction with dichloromethane, the components are separated by high-pressure liquid chromatography without further clean-up or concentration on a column packed with small-particle silica gel. The mean recovery from plasma is 98.6% with a relative standard deviation of 1.6%. The detection limit for carbamazepine is approximately 2 ng/ml, requiring 1 ml of plasma. 相似文献
996.
Oleg V. Mikhailov Marina A. Kazymova Tatyana A. Shumilova Galina A. Chmutova Svetlana E. Solovieva 《Transition Metal Chemistry》2005,30(3):299-304
The complexing process proceeding in the NiII–thiocarbohydrazide (H2N–H–NC(=S)–NH–NH2)–propanone triple system in EtOH solution and nickel(II)hexacyanoferrate(II) gelatin-immobilized matrix has been studied. It has been found that in the first case, template synthesis leading, as a minimum, to formation of three coordination compounds of NiII with (N,N,S,S)-donor tetradentate ligands having NiL1, NiL2 and NiL3compositions where L1 is 4,6,6-trimethyl-2,3,7,8-tetraazanonen-3-di(thiohydrazide)-1,9, L2 is 4,6,6,12-tetrametyl-1,9-dithio-2,3,7,8,10,11-hexaazatridekadien-3,11-hydrazide-1 and L3 is 2,8,10,10,16-pentamethyl-5,13-dithio-3,4,6,7,11,12,14,15-octaazaheptadekatrien-2,7,15 is observed, whereas in the gelatin-immobilized matrix, a complexing process in the system considered does not occur. 相似文献
997.
Zusammenfassung Der Vorgang der thermischen Umlagerung des 4-Hydroxy-5-acetyl-6-phenyl-pyrons-(2) (1) zum 4-Hydroxy-5-benzoyl-6-methyl-pyron-(2) (4) wird an Hand weiterer Beispiele studiert und ferner der Einfluß der Substituenten am C-5 bzw. C-6 des Lactonringes untersucht.
An investigation of more examples of the thermal rearrangement of 5-acetyl-4-hydroxy-6-phenyl-pyrone-(2) to 5-benzoyl-4-hydroxy-6-methyl-pyrone-(2) was carried out, it showed the influence of substituents at C-5 and C-6 of the lactone ring.相似文献
998.
Zusammenfassung Eine dünnschichtchromatographische Trennung des Wismuts von einem Überschuß an Metallen der Schwefelwasserstoffgruppe wurde beschrieben. Als Laufmittel dient ein Gemisch von tert.-Butanol, Salzsäure und Wasser. Nach Absaugen der Sorptionsschicht wird das Wismut mit MDCM spektralphotometrisch bestimmt. Standardabweichung und Varianz des Verfahrens werden angegeben.
Summary A thin layer Chromatographic separation of the bismuth from an excess of metal ions of the hydrogen sulfide group is described. A mixture of tert. butanol, hydrochloric acid and water serves as mobile phase. After sucking off the sorption layer, the bismuth is determined spectrophotometrically with MDCM. The standard deviation and the variance of the procedure is given.
Résumé On décrit une séparation par Chromatographie en couche mince du bismuth de métaux en excès du groupe de l'hydrogène sulfuré. On utilise comme éluant un mélange de butanol tert., d'acide chlorhydrique et d'eau. Après aspiration de la couche de sorption, on dose par spectrophotométrie le bismuth par le MDCM. On communique l'écart-type et le coefficient de variation du procédé.相似文献
999.
H. B. STEEN 《Photochemistry and photobiology》1967,6(11):805-816
Abstract— The lumincscence arising from L-tryptophane and L-tyrosine in aqueous solutions at 77K during irradiation with u.v.-light and with X-rays has been studied. The spectra obtained with the two types of radiation were largely similar, differing only in that the yields of phosphorescence relative to fluorescence were considerably enhanced in the case of X-irradiation. The decay times observed for the exponentially decaying phosphorescence, being 6.6 sec and 2.7 sec for tryptophane and tyrosine respectively, were the same for both kinds of irradiation. The G-value of the X-ray induced luminescence was about 10 for both tryptophane and tyrosine. Thus, about 30 per cent of the total energy absorbed from X-rays in these compounds was re-emitted as light.
It was concluded that the X-ray induced fluorescence and phosphorescence originate from the same levels as does the luminescence caused by u.v.-light, i.e. the lowest excited singlet and the lowest triplet level of the aromatic structure of these compounds. In the case of X-irradiation the enhanced ratios between the yields of phosphorescence and fluorescence indicated that some process other than excitation directly from the ground state contributed considerably to the luminescence yields. Assuming this process to be a recombination between the ionized molecule and its electron, it was calculated that the contribution to the luminescence yield from excitations directly from the ground state relative to that from ionizations, was negligible for both compounds. 相似文献
It was concluded that the X-ray induced fluorescence and phosphorescence originate from the same levels as does the luminescence caused by u.v.-light, i.e. the lowest excited singlet and the lowest triplet level of the aromatic structure of these compounds. In the case of X-irradiation the enhanced ratios between the yields of phosphorescence and fluorescence indicated that some process other than excitation directly from the ground state contributed considerably to the luminescence yields. Assuming this process to be a recombination between the ionized molecule and its electron, it was calculated that the contribution to the luminescence yield from excitations directly from the ground state relative to that from ionizations, was negligible for both compounds. 相似文献
1000.
The C2H4 was investigated ab initio for the equilibrium distance of the centers, taking all 16 electrons into account, using the Allgemeines Programmsystem/SCF ? MO ? LC (LCGO ) Methode. A total energy of ?76.77 a.u. and an ionization energy of 10.55 eV were found. 相似文献