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11.
K. D. Duch M. Heel H. Kalinowsky F. Kayser E. Klempt B. May O. Schreiber P. Weidenauer M. Ziegler D. Bailey S. Barlag J. M. Butler U. Gastaldi R. Landua C. Sabev W. Dahme F. Feld-Dahme U. Schaefer W. R. Wodrich J. C. Bizot B. Delcourt J. Jeanjean H. Nguyen E. G. Auld D. A. Axen K. L. Erdman B. Howard R. Howard B. L. White S. Ahmad M. Comyn G. M. Marshall G. Beer L. P. Robertson M. Botlo C. Laa H. Vonach C. Amsler M. Doser J. Riedlberger U. Straumann P. Truöl ASTERIX Collaboration 《Zeitschrift fur Physik C Particles and Fields》1989,45(2):223-234
Antiproton-proton annihilation at rest in a gaseous H2 target at NTP into the final state π+ π? K ± π? (K 0) with an undetectedK 0 or \(\bar K^0 \) has been investigated. We observe theE(1420) resonance in the invariant mass spectrum (K 0)miss K ± π? with massM E =1413±8 MeV/c2 and widthГ E =62 ± 16MeV/c2 and find evidence for the production of thef 1(1285). The absolute branching ratio of \(\bar p\) p → π+ π? E 0,E 0 →K 0 L K ± π ? at (61±6)%P wave annihilation is (3.0±0.9)·10?4 of all annihilations. The observed suppression of theE production fromP wave with respect to theS wave together with some simple selection rules suggest that the quantum numbers of theE(1420) areJ pc=0?+ and not I++. 相似文献
12.
Th. Kappe E. Ziegler M. Ali A. Chirazi 《Monatshefte für Chemie / Chemical Monthly》1969,100(1):142-145
Zusammenfassung Perimidon (1) reagiert mit monosubstit. Malonsäure-trichlorphenylestern (2) bei 250° zu 9-Hydroxy-5,7-dioxo-4,5-dihydro-7H-pyrido[1,2,3-cd]perimidinen (3), die durch saure Hydrolyse zu 10-Amino-4-hydroxy-benzo[h]carbostyrilen (4) gespalten werden.
Syntheses of heterocycles, CXXII: Reaction of perimidone with reactive malonates
Perimidone (1) reacts with monosubstituted 2.4.6-trichlorophenyl malonates at 250° to 9-hydroxy-5.7-dioxo-4.5-dihydro-7H-pyrido[1.2.3-cd]perimidines (3), which are cleaved by acid yielding 10-amino-4-hydroxy-benzo[h]quinolin-2-ones (4).相似文献
13.
G. Ziegler S. V. K. Kumar P. Dittmann K. Bergmann 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1988,10(2-3):247-252
Differential cross sections for state-to-state rotationally inelastic electron-Na2 scattering, with the molecule being in the vibrational levelv′'=31, are measured at a collision energy of 150 eV. Angular momentum transfer of up to Δj=26 is observed, which is even more than previously obtained for the vibrational ground statev′'=0. Good agreement is found with theoretical results from a spectator scattering model. This work, in general, elucidates the role of vibrational excitation in collision dynamics under vibrationally sudden conditions. 相似文献
14.
The first implementation of the intrinsic reaction coordinate (IRC ) method within the density functional theory (DFT ) framework is presented. The implementation has been applied to four different types of chemical reactions represented by the isomerization process, HCN ? HNC (A); the SN2 process, H? + CH4 ? CH4 + H? (B); the exchange process, H˙ + HX ? HX + H˙ (X ? F,Cl) (C); and the elimination process, C2H5Cl ? C2H4 + HCl (D). The present study presents for each process optimized structures and calculated harmonic vibrational frequencies for the reactant(s), the transition state, and the product(s) along with the IRC path connecting the stationary points. The calculations were carried out within the local density approximation (LDA ) as well as the LDA/NL scheme where the LDA energy expression is augmented by Perdew's and Becke's nonlocal (NL ) corrections. The LDA and LDA/NL results are compared with each other as well as the best available ab initio calculations and experimental data. For reaction (D), ab initio calculations based on MP 2 geometries and MP 4SDTQ energies have been added due to the lack of accurate published post-HF calculations on this process. A detailed discussion is provided on the efficiency of the IRC algorithms, the relative accuracy of the DFT and ab initio schemes, as well as the reaction mechanisms of the four reactions. It is concluded that the LDA/NL scheme affords the same accuracy as does the MP 4 method. The post-HF methods seem to overestimate activation energies, whereas the corresponding LDA/NL estimates are too low. The LDA activation energies are even lower than the LDA/NL counterparts. The incorporation of the IRC method into the DFT framework provides a promising and reliable tool for probing the chemical reaction path on the potential energy surfaces, even for large-size systems. IRC calculations by ab initio methods of an accuracy similar to the LDA/NL scheme, such as the MP 4 scheme, are not feasible. © John Wiley & Sons, Inc. 相似文献
15.
Zusammenfassung 4-Hydroxy-carbostyrile (1a–c) werden mit Benzylchlorid inDMF bevorzugt zu den 4-Benzyloxy-carbostyrilen (2a–c) alkyliert. In wäßr. NaOH dagegen erhält man aus1a und1c als Hauptprodukt das 3,3-Dibenzyl-2,4-dioxo-1,2,3,4-tetrahydrochinolin (3).
Alkylation of 4-hydroxy-quinol-2-ones (1a–c) with benzyl chloride inDMF in the presence of K2CO3 mainly gives the 4-benzylethers2a–c. However, carbon dialkylation takes place in aqueous NaOH and the main product of the reaction between benzylchloride and1a is 3.3-dibenzyl-2.4-dioxo-1.2.3.4-tetrahydro-quinoline3.相似文献
16.
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
17.
Zusammenfassung Kürzlich wurde in einer Publikation vonA. K. Bose undS. Garratt über eine neue Synthese von substituierten Barbitursäuren aus Malonsäuren und substituierten Malonsäuren mit Carbodiimiden berichtet. Hierdurch sehen wir uns veranlaßt, über unsere bisherigen Ergebnisse im Rahmen ähnlicher Untersuchungen kurz zu berichten. 相似文献
18.
Zusammenfassung Es werden einstufige Synthesen desGlomerins (2) [1,2-Dimethyl-4(1H)-chinazolinon] und desArborins (3) [1-Methyl-2-benzyl-4(1H)-chinazolinon] bekanntgegeben.
Syntheses of heterocycles, CXXX: Glomerine and arborine
A one step synthesis ofglomerine (2) [1.2-dimethyl-4(1H)-quinazolinone] andarborine (3) [1-methyl-2-benzyl-4(1H)-quinazolinone] is described.相似文献
19.
Max Ziegler und Horst Winkler 《Fresenius' Journal of Analytical Chemistry》1959,166(4):241-242
Zusammenfassung Durch die Anwendung eines H2S-haltigen Laufmittels werden die Ionen Cu2+, Pb2+, Bi3+ und Hg2+ am Startpunkt des Chromatogramms als Sulfide fixiert, während Cd2+ nach kurzer Laufzeit in scharf begrenzter Zone als Sulfid im Chromatogramm nachgewiesen wird. Als Arbeitsgefäße dienen Reagensgläser. Die Spezifitäten liegen für 5 g Cd bei Cd2+Cu2+=12000, Cd2+Pb2+=12000, Cd2+Bi3+=12000, Cd2+Hg2+=1100.Herrn Prof. Dr. O. Glemser, Direktor des Anorganisch-chemischen Insituts der Universität Göttingen, danken wir für Unterstützung der Arbeit. 相似文献
20.
Zusammenfassung Die Abhängigkeit der Struktur des o-Hydroxymandelsäurelactons von Lösungsmittel und Temperatur wird mit Hilfe IR- und NMR-spektroskopischer Methoden nachgewiesen.
The temperature and solvent dependence of the structures of 2-hydroxymandelic acid lactone and dioxindole have been shown by IR and NMR spectroscopy.相似文献