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1.
E. G. Mesropyan E. N. Dzhandzhapanyan M. T. Dangyan 《Chemistry of Heterocyclic Compounds》1968,4(6):695
In the reaction between -chloro--hydroxy--valerolactone and potassium phthalimide in dimethylformamide, -phthalimido--hydroxy-valerolactone is formed, alkaline hydrolysis of which gives -hydroxylevulinic acid. It is shown that oxidation of di(-chloroallyl)malonic acid with hydrogen peroxide in acetic acid gives the dilactone of bis(-hydroxy--chloro--hydroxy)malonic acid. 相似文献
2.
V. V. Martishonok O. A. Grinkevich V. I. Biba O. N. Bubel' 《Chemistry of Heterocyclic Compounds》1992,28(1):18-21
-(1-Ethoxyvinyl)- and -(1-ethoxyvinyl)--ethoxycarbonyl--butyrolactones were obtained by the reaction of 2-(1-ethoxyvinyl)oxiranes with sodiomalonic ester. Decarboxylation of the -(1-ethoxyvinyl)--ethoxycarbonyl-butyrolactones in DMSO leads to -(1-ethoxyvinyl)--butyrolactones, the hydrolysis of which gives -acetyl-butyrolactones. Ethyl trans-3-acetyl-3-pentenoate was obtained by decarboxylation of -methyl--(1-ethoxyvinyl)--ethoxycarbonyl--butyrolactone in DMSO.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 22–25, January, 1992. 相似文献
3.
A. Harada S. Takahashi 《Journal of inclusion phenomena and macrocyclic chemistry》1984,2(3-4):791-798
Inclusion compounds of ferrocene(FcH) and its derivatives with cyclodextrins(CDs; -CD, -CD, and -CD) were prepared. CD-ferrocene inclusion compounds were obtained in a crystalline state in high yield. -CD and -CD formed 11 stoichiometric inclusion compounds with ferrocene and its derivatives. -CD formed 21 (CD:guest) complexes with ferrocene and the monosubstituted derivatives, but did not form complexes with 1,1-disubstituted derivatives, -CD-FcH and -CD-FcH complexes are thermally stable and do not liberate ferrocene on heating at 100°C in vacuo. The cyclodextrin inclusion compounds were characterized by1H-NMR, IR, UV, and CD spectra. A large positive induced Cotton effect was observed in the case of -CD-FcH complex, while the -CD-FcH complex showed a negative spectrum. The binding mode is discussed. -Cyclodextrin was found to form inclusion complexes in ethylene glycol, diethylene glycol, triethylene glycol, methyl cellosolve, ethyl cellosolve, methyl alcohol, and glycerine solutions. -CD also formed complexes in ethylene glycol solution. The binding of ferrocene by -CD is stronger in ethylene glycol than in dimethyl sulfoxide and dimethyl formamide. 相似文献
4.
Robert L. Schiller Stephen F. Lincoln John H. Coates 《Journal of inclusion phenomena and macrocyclic chemistry》1987,5(1):59-63
Equilibrium and temperature-jump spectrophotometric studies show that the mono-cation of pyronine B (PB) is included by beta- and gamma-cyclodextrins (CD and CD) to form the labile complexes PB. CD, PB. CD and (PB)2. CD in water. The equilibrium, kinetic and structural aspects of these complexes and those formed by pyronine Y are discussed in conjunction with data characterizing the inclusion of other dyes by cyclodextrins. 相似文献
5.
Reaction of ,-dipyridyl with sulfur trioxide at room temperature gives ,-dipyridyld'isulfotrioxide, which latter on heating at 200° gives ,-dipyridyl-sulfonic acid. Salts of ,-dipyridyl-3-sulfonic acid are prepared, among them the potassium, sodium, barium, and 3-cyano-,-dipyridyl salts.For Part VI see [1]. 相似文献
6.
Iztok Turel Alojz Demšar Janez Košmrlj 《Journal of inclusion phenomena and macrocyclic chemistry》1999,35(4):595-604
The inclusion of titanocene dihalides (X = F, Cl) into -, - and -cyclodextrin hosts was studied by NMR spectroscopy, thermal analysis and mass spectrometry. It was found that -cyclodextrin does not form inclusion complexes with titanocene halides whereas - and -cyclodextrin do form such complexes. According to the changes in NMR spectra we propose that there is a shallow penetration of a guest molecule of titanocene dihalide into the cavity in the case of -cyclodextrin, but deeper penetration in the case of -cyclodextrin. The stability of the latter inclusion complexes was studied by NMR shift titration. 相似文献
7.
Xizhang Feng 《Journal of Radioanalytical and Nuclear Chemistry》1991,151(1):41-46
In the present paper, a new improved expression for -ray detection efficiency of Ge(Li) detectors,
0
, is given. It is represented as a continuous function of x (viz. E
–1) with a maximum and decreases very rapidly to a small positive value as -ray energy, E, drops to 40 keV or lower, but slowly as E rises to 1.7 MeV or higher. Since it can well represent the whole physical process of the -ray detection, this expression may be one of the simplest and most precise representations, for
0
at the present time. 相似文献
8.
,-Dibromo--('-carbethoxyacetony)-,-butenolide (I) reacts with amines in diethyl ether solution to give -bromo-amino--('-carbethoxyacetony)-,-butenolides. Compounds n are converted to -bromo-amino--('-carbethoxyacetony)-,-butenolides on reaction with amines. The corresponding arylhydrazones (VI and VII) are obtained by the reaction of I and II with p-nitro- and 2,4-dinitrophenylhydrazines. Compound I reacts with phenylhydrazine to give furopyridazine VIII.See [1] for communication IV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 867–871, July, 1972. 相似文献
9.
Influence of sodium on the phase composition of bismuth-molybdenum oxide catalysts supported on SiO2
E. L. Sazonova L. P. Olenkova L. M. Plyasova D. V. Tarasova 《Reaction Kinetics and Catalysis Letters》1977,7(4):413-417
Using an x-ray phase analysis, it has been shown that the application of sodiumstabilized sols to the Bi2O3·2.75MoO3/SiO2 system leads to the interaction of molybdenum and bismuth oxides with sodium, and the formation of a double Na–Bi-molybdate.
, Bi2O3·2.75 MoO3/SiO2 , , Na–Bi-.相似文献
10.
L. Guczi Z. Schay J. Stoch J. Czeppe J. Haber 《Reaction Kinetics and Catalysis Letters》1982,18(1-2):199-202
Crystalline Ru3(CO)12 and Fe3(CO)12 carbonyl clusters were deposited on a Cu sample holder and core level binding energies (BE) for O 1s, C 1s Fe 2p 3/2, Fe 2p 1/2, Ru 3d 5/2 and Ru 3d 3/2 were measured before and after decomposition. Part of the carbonyl clusters remained in the original form even at a pressure of 10–5 Pa, indicated by a Fe satellite peak and high BE for C 1s. After decomposition, carbon is partly retained by iron, whereas the twin peak at Ru 3d 5/2 and Ru 3d 3/2 show no carbon left on the ruthenium surface.
Ru3(CO)12 Fe3(CO)12 (BE) O 1S, C 1S, Fe 2p 3/2, Fe 2p 1/2, Ru 3d 5/2 Ru 3d 3/2 . 10–5 Pa, Fe BE 1S. , Ru 3d 5/2 Ru 3d 3/2 , .相似文献
11.
M. Szögyi T. Cserháti J. Szejtli 《Journal of inclusion phenomena and macrocyclic chemistry》1987,5(4):433-437
Nonylphenyl-ethyleneoxide polymers containing 5, 9 and 30 ethyleneoxide groups per molecule build into the hydrophobic fatty acid chains of the cell membrane phospholipid dipalmitoyl-phosphatidylcholine (DPPC) resulting in a decreased main transition temperature, a decreased enthalpy of the main transition and in enhanced potassium permeability of DPPC liposomes. The -, - and -cyclodextrins form inclusion complexes with the tenzides lowering their free concentration. The complex formation lessens or sometimes totally prevents the membrane damaging effect of tensides. The effectivity order of cyclodextrins is CD>CD>CD.Presented at the Fourth International Symposium on Inclusion Phenomena and the Third International Symposium on Cyclodextrins, Lancaster, U.K. 20–25 July 1986. 相似文献
12.
Liquid-phase hydrogenation of cyclohexene by dihydrogen in the presence of dimolybdenum tetraacetate
Catalytic liquid-phase hydrogenation of cyclohexene in DMF by dihydrogen in the presence of dinuclear bridged complex Mo2(OAc)4 has been studied. A kinetic equation for the steady-state rate of cyclohexene hydrogenation and the activation parameters are suggested.
Mo2(OAc)4. .相似文献
13.
J. J. Bikerman 《Colloid and polymer science》1965,201(1):48-51
Summary Surface tension
e of mercury in equilibrium with crystals (floating on its surface) of octacosane, 1-hexadecanol, 1-octadecanol, ethyl palmitate, benzophenone and azoxybenzene at 7° is almost equal to that at 23° (measured earlier); also the difference between the surface tension (
0) of uncontaminated mercury and
e (i. e., equilibrium surface pressure) is independent of temperature within the limits of the experimental error. This shows that the hypothesis making
0-
e an analog of the vapor pressure of the solid is incorrect. The relation
e= (=cohesion of the crystal,=thickness of the surface layer of mercury) is in agreement with the negligible temperature coefficient of
e
. The calculated is approximately 9 angstroems.
Zusammenfassung Die Oberflächenspannung e von Quecksilber im Gleichgewicht mit Kristallen (schwimmend auf der Oberfläche) von Octosane, 1-hexadecanol, 1-octodecanol, Äthylpalmitat, Benzophenon und Azoxylbenzol bei 7 °C ist nahezu gleich der bei23 °C gemessenen. Auch die Differenz der Oberflächenspannung von reinstem Quecksilber ( 0) und ( e), d. h. dem Gleichgewichtsobderflächendruck ist unabhängig von der Temperatur innerhalb der experimentellen Fehlergrenze. Dies zeigt, daß die Hypothese, nach der man 0- e in Analogie zum Dampfdruck des Festen betrachtet, unkorrekt ist. Die Beziehung e= (=Kohäsion des Kristalls,=Dicke des Oberflächenfilms auf Quecksilber) ist in Übereinstimmung mit dem vernachlässigbaren Temperaturkoefifzienten von e. Das berechnete beträgt ungefähr 9 Å.相似文献
14.
Zs. Révay T. Belgya P. P. Ember G. L. Molnár 《Journal of Radioanalytical and Nuclear Chemistry》2001,248(2):401-405
HYPERMET PC is a user-friendly -ray spectrum analysis software package developed at Budapest, mainly for the purpose of prompt- neutron activation analysis (PGAA). The peak fitting algorithm is an improved version of the well-known HYPERMET code, and contains a partial peak-parameter calibration to describe peak shapes more accurately in the wide energy range typical for prompt- spectra. A nuclide identification routine has also been developed using a new PGAA library, shown in a parallel paper. The new module for quantitative PGAA includes all the features necessary to obtain concentration values for elements. 相似文献
15.
J. Major H. Schneider A. Seeger A. Siegle H. Stoll I. Billard M. Koch U. Lauff 《Journal of Radioanalytical and Nuclear Chemistry》1995,190(2):481-491
Correlated measurement of the lifetime and of the lineshape of the 511 keV annihilation radiation of positrons (age-momentum correlation, AMOC) has become a powerful tool for investigating reactions of positron or positronium in condensed matter as a function of time. The beam-based
+ AMOC method installed at the Stuttgart relativistic positron beam facility (E
kin
e+
4MeV) offers substantial advantages over the conventional E coincidence technique resulting in a fast data taking due to the unity detection efficiency of the
+ scintillator which provides the start signal for the lifetime measurement. In this paper the application of AMOC to positronium chemistry is illustrated by the study of spin conversion of positronium in the system methanol/HTEMPO as a function of HTEMPO (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, a paramagnetic solute) concentration. The same technique can be applied to other systems and other reactions in positronium chemistry, e. g., oxidation or complex formation. 相似文献
16.
A graph is said to be embedded in a graph if is isomorphic to a subgraph of . The embedding frequency for in ,N( , ), is the number of different subgraphs of to which is isomorphic. We use a computer program to calculate the embedding frequencies of subtrees within trees. We computeN(, ) for trees through 10 vertices and present the results in tabular form. When trees are partially ordered by valence class, their subtrees lie in corresponding order; we give a formal proof of this subtree embedding property. The structure of the embedding relation is exhibited in a topological picture of the zeta function showing the non-zero values ofN(, ). 相似文献
17.
A. A. Ziyaev O. S. Otroshchenko A. S. Sadykov G. A. Tolkacheva 《Chemistry of Heterocyclic Compounds》1969,5(2):276-276
In a study of the dimerization of N-methylanabasine in the presence of metallic sodium under conditions for the dimerization of pyridine, it was found that the reaction does not take place at room temperature while at 50–70° C it leads to the formation of,-di(1-methylpiperid-2-yl)-,-bipyridyl. Oxidation of the latter yielded 4,4-bipyridyl-5, 5-dicarboxylic acid, the decarboxylation of which gave,-bipyridyl. 相似文献
18.
The effects of the nature of the aryl substituents and the reaction conditions on the bromination of 3,5-diaryl-1,2-oxathiolane 2-oxides (-sultines) have been studied. The possible mechanisms for the bromination of the -sultines are discussed on the basis of the experimental data. 相似文献
19.
Maria Nowakowska Mirosława Smoluch Dorota Sendor 《Journal of inclusion phenomena and macrocyclic chemistry》2001,40(3):213-219
The effect of -, - and -cyclodextrin onthe photochemical stability of 7-amino-4-methylcoumarin (C120)was studied. Using spectroscopic techniques (UV/Vis absorption spectroscopy, fluorescence, fluorescence anisotropy and circular dichroism) combined with HPLC/MS and MS analysis it was demonstrated that addition of -cyclodextrin to the aqueoussolution of C120 markedly inhibits the photodegradation of that dye. This results from theformation of an inclusion complex between C120 and -cyclodextrin. 相似文献
20.
Joaquín Velasco Carmen Carmona María A. Muñoz Pilar Guardado Manuel Balón 《Journal of inclusion phenomena and macrocyclic chemistry》1999,35(4):637-648
The interactions between cyclodextrins and tetrahydroharmane, 1-methyl-1,2,3,4-tetrahydro-9H-pyrido/3,4-b/indole, have been investigated in pH 10.1 aqueous media. Absorption and fluorescence studies, together with lifetime measurements show that tetrahydroharmane forms ground state inclusion complexes with -CD and -CD but not with -CD. Steady state experiments detect only one kind of tetrahydroharmane--CD complex, whereas time resolved measurements reveal the existence of two different types of 1:1 association complexes. The results in -CD are very similar to those in -CD, but the interactions are much weaker. 相似文献