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1.
The conductance of tetrabutylammonium tetraphenylboride, picrate, perchlorate, and nitrate has been measured at 25°C in mixtures ofi-butyronitrile with chlorobenzene,o-dichlorobenzene,p-dicholorobenzene, 1,2-dichloroethane, andn-pentanol covering the range of dielectric constants 10D20. In these mixtures of polar solvents, both association constants and ionic mobilities depend on ion-solvent interaction energies and on free volume in a manner that is specific for each system. This failure of the primitive model (rigid charged spheres in a continuum) is shown to be the consequence of short-range spatial and energetic interactions between ions and adjacent solvent molecules.  相似文献   

2.
The molecular complexation ofDDT (acceptor) with some compounds of biological interest as donors (e.g. indole, 2-methylindole, 3-methylindole, benzene and naphthalene) have been studied using refractive index,Guggenheim and dielectric titration plot methods. The interaction between these donors with solvents (CCl4 and C6H6) have also been observed by calculating ind through ind=solinert. These data have shown that the molecular interaction between polar solutes and non-polar aromatics is governed by dipole-induced dipole electrostatic attraction. The dipole moment obtained due to charge transfer (DA) has also been calculated and found that its value increases with the increase in the extent of interaction between donor and acceptor. These data support the charge-transfer complex formation hypothesis for the mode of action ofDDT on molecular level.
Dielektrizitäts-Untersuchungen an Molekülkomplexen von DDT mit einigen biologisch relevanten Verbindungen
Zusammenfassung Es wurden Molekülkomplexe vonDDT (als Acceptor) mit einigen Verbindungen von biologischem Interesse (als Donoren: Indol, 2-Methyl-indol, 3-Methyl-indol, Benzol und Naphthalin) mittels Brechungsindex,Guggenheim-Methode und dielektrischer Titration untersucht. Dipolmomentberechnungen ergaben, daß die intermolekulare Wechselwirkung von einer Anziehung induzierter Dipol-Dipol bestimmt wird; es wurde auch der charge-transfer-Anteil des Dipolmoments abgeschätzt. Alle diese Daten unterstützen die Annahme der charge-transfer-Komplexierung vonDDT.
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3.
Mo2Cl4 Pic 4·CHCl3 (A) (Pic=4-methylpyridine) and Mo2Br4 Pic 4 (B) crystallize in the monoclinic space group.A inC2/c (No. 15) witha=15.175 (4),b=10.847 (2),c=19.946 (6) and =104.52 (2)°;D o=1.71 (2),D c =1.72 gcm–3 forZ=4.B inP2l/n (No. 14) witha=9.270 (3),b=16.614 (5),c=9.305 (3) and =91.96 (5)°;D o=2.03 (3),D c =2.05 gcm–3 forZ=2.Two halogens and 4-methylpyridines of the MoX 2 Pic 2 group are in the trans position. Mo–Mo bond lengths are 2.153 96) forA and 2.150 92) forB. Both molecules are situated on the inversion center resulting in the eclipsed configuration of the ligands around the molybdenum pair. The structure ofB has been refined to the conventionalR factors of 0.08 and 0.098. Disorder on the part of 4-methylpyridines and chloroform molecules stopped the refinement ofA at the endR value of 0.175.Mean Mo–X and Mo–N bonding distances are 2.40 (2), 2.25 (5) forA and 2.53 (3), 2.25 (1) forB.
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4.
5-Hydroxy-p-menth-6-en-2-one (1) and 10-hydroxy-4-cadinen-3-one (2) were isolated from pyrolytic products of Incense Aden (gum resin ofBoswellia carteri Birdw.). The relative and absolute configurations of these compounds were determined on the basis of spectral and chemical evidences.
Für Darstellung und Auftrennung des Weihrauchpyrolysates einschließlich der SC-Vortrennung siehe  相似文献   

5.
Alkyl and alkenyl quinolines (so-called Pyo-substances) and theirN-oxides were isolated fromPseudomonas aeruginosa. Structures proposed earlier could be confirmed; a new representative (Pyo V) is described.
IV. Mitt.:A. Römer, H. Budzikiewicz, H. Korth undG. Pulverer, Tetrahedron Letters1979, 509.  相似文献   

6.
Summary In order to get better insight into the structural reasons for different properties of copper(II) complexes withL-threonine,L-allo-threonine,L-N,N-dimethyl-threonine, andL-N,N-dimethyl-allo-threonine, their EPR spectra were studied as a function ofpH and temperature. AtpD9.4, in all complexes a change in the copper(II) coordination sphere from the glycine to the hydroxy type was observed. Inbis(L-threoninato)copper(II), the hydroxy type formed atpD9.4 was found to be stablized by increasing the temperature of the solution from 280 to 320 K. In all other copper(II) complexes, the conformational change is accompanied by the disruption of the Cu-N bond of one chelate ring.
Vergleichende EPR-Untersuchungen von Kupfer(II)-Threonin-Komplexen
Zuzammenfassung Um einen besseren Einblick in die Beziehungen zwischen Struktur und Eigenschaften von Kupfer(II)-Komplexen mitL-Threonin,L-allo-Threonin,L-N,N-Dimethyl-Threonin undL-N,N-Dimethyl-allo-Threonin zu gewinnen, wurden ihre EPR-Spektren in Abhängigkeit vompH-Wert und von der Temperatur untersucht. Bei einempH-Wert von 9.4 (in deuterierter Lösung) wurde eine Veränderung in der Kupfer (II)-Koordinationssphäre festgestellt, die von einer Glycin-ähnlichen Konformation in eine vermutlich Hydroxy-ähnliche Konformation übergeht. Derbis(L-Threoninato)-Kupfer (II)-Hydroxy-Komplex wird durch eine Temperaturerhöhung von 280 auf 320K stabilisiert. Die Veränderung der Koordination vom Glycin-Typ wird von einem Bruch der Cu-N-Bindung eines Chelatrings begleitet.
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7.
Condensation of alkyl -haloacetoacetates (or -chloroacetoacetanilide) with triethoxymethane and primary (hetero)aromatic amines gives in a one step synthesis under mild conditions new ,-diacyl-enamines (2 a-m, 3 a-d). In contrast, the N-alkylsubstituted derivatives could be synthesized only in a two step procedurevia the enolethers6 a, b. According to their ir-specra, most of the aminomethylene--haloacetoacetic acid derivatives are stereochemically fixed either in theE- orZ-form. The pmr-spectra, however, show that they exist as mixtures of at least two isomers in solution.With KOH or sodium acetate, a ring closure to 3-hydroxy-pyrroles (8, 9) could be achieved whereas with pyridine only quarternary pyridinium salts (11) are formed. Acidic (orLewis acidic) condensing agents leave the chloroacetyl group unaffected and give either free carboxylic acids (2 p-r) pyrido-[1,2-a]pyrimidones (12) or 4-quinolones (13), depending on the type of the molecule and the reaction temperatures employed.
Synthesen von Aminomethylen--halogenacetessigsäurederivaten und deren Ringschlußreaktionen zu 3-Hydroxypyrrolen, Pyrido[1,2-a]pyrimidonen bzw. 4-Chinolonen ,-Diacyl-enamine und-enole, 5. Mitt.
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8.
Two ternary phase diagrams of the cationic perfluorosurfactant diethanolheptadecafluoro-2-undecanolmethylammonium chloride (DEFUMAC) with an anionic perfluorosurfactant lithium perfluorooctanesulfonate (LiFOS) and an anionic hydrocarbon surfactant lithium dodecyl sulfate (LiDS) have been established at 25°C. The total surfactant concentration was less than 20wt%. In a wide mixing region of the LiFOS/DEFUMAC system, a lamellar-type phase,P , was identified by its texture under a polarization microscope and by its x-ray diffraction pattern. Dispersed fragments ofP -phase are present in the dilute solutions in which one surfactant was in excess. The anisotropy of electrical conductivity, flow birefringence, dynamic light scattering, and electric briefringence demonstrate that theP fragments are disk-like with a radius of 0.7 m. The disk-likeP particles are transformed by shear into a spherical aggregate ofL above a critical shear gradient. LiDS/DEFUMAC mixed solution forms dispersed and precipitatedL in the dominant region. Radius and micropolarity of the dispersedL aggregates are decreased as the ratio of LiDS:DEFUMAC approaches 1:1. On the basis of x-ray diffraction measurement the structure of precipitatedL -phase seems to consist of monolayers.  相似文献   

9.
Polarographic study of Pd(II) reveals that it reduces quasireversibly at d.m.e. in 0.2M-pyridine+0.1N-HCl medium. Kinetic parameters of Pd(II) in various concentrations of -resorcyclic acid were calculated usingGellings method and thus the effect of concentration of -resorcyclic acid on the kinetics of the reduction of Pd(II) has been explained.DeFord/Hume graphical extrapolation method and the mathematical method ofMihailov have been employed for the evaluation of overall formation constants of the complexes formed with -resorcyclic acid. The logarithmic values of overall formation constants 1, 2 and 3 obtained by the two methods are 7.47, 8.60, 9.66 (DeFord andHume Method) and 7.44, 8.64, 9.66 (Mihailov Method) at 298 K. Thermodynamic parameters of these complexes are reported.
Elektrodenkinetik und thermodynamische Untersuchungen an Pd(II)-Komplexen mittels polarographie
Zusammenfassung Pd(II) zeigt eine quasireversible Reduktion in 0,2M-Pyridin/0,1N-HCl. Kinetische Parameter wurden mittels der Methode vonGelling ermittelt und damit der Effekt verschiedener -Resorcylsäurekonzentrationen erklärt. Bildungskonstanten der entsperechenden Komplexe wurden nachDeFord/Hume und nachMihailov ermittelt. Die logarithmischen Werte der Gesamtbildungskonstanten 1, 2 und 3 bei 298 K betragen nach derDe Ford/Hume-Methode 7,47, 8,60 und 9,66, nach derMihailov-Methode 7,44. 8,64 und 9,66. Die thermodynamischen Parameter der Komplexbildung werden angegeben.
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10.
Reaction of methyl -D-galactopyranoside (1) with two equivalents oft-butyldimethylchlorosilane yields methyl 2,6-bis-O-(tBDMSi)--D-galactopyranoside (1 b), methyl 3,6-bis-O-(tBDMSi)--D-galactopyranoside (1 c) and methyl 4,6-bis-O-(tBDMSi)--D-galactopyranoside (1 d). Likewise methyl -D-mannopyranoside (6) affords methyl 2,6-bis-O-(tBDMSi)--D-mannopyranoside (6 d) and methyl 3,6-bis-O-(tBDMSi)--D-mannopyranoside (6 b), which can be isomerised withTPP/DEAD to methyl 4,6-bis-O-(tBDMSi)--D-mannopyranoside (6 f). Methyl 6-O-(tBDMSi)--D-galactopyranoside (1 a) and methyl 6-O-(tBDMSi)--D-mannopyranoside (6 a) can be prepared from1 or6 with one equivalent oft-butyldimethylchlorosilane.Without an external nucleophile the sugar derivatives1 a and1 b react withTPP/DEAD to form the 3,4-carbonato--D-galactopyranosides1 h and1 i and the 3,4-carbonato-2-O-ethoxycarbonyl--D-galactoside (1 j). In contrast to the formation of the compound1 i by means ofTPP/DEAD the reaction of1 a withTPP and Di-t-butyl-azodicarboxylate (DTBAD) yields the 2,3-anhydro--D-taloside (4 b) and only a small amount of1 i. The epoxide4 b can be cleaved withp-nitrobenzoylchloride/pyridine to the 3-chloro-3-deoxy-2,6-di-O-p-nitrobenzoyl--D-idoside (5). Reaction of1 c and1 d withTPP/DEAD yields the 2,3-anhydro--D-gulopyranoside (2), which can be transformed with NaN3/NH4Cl to the 2-azido-2-deoxy--D-idopyranoside (3).Likewise6 a and6 d can be converted to the 3,4-anhydro--D-talosides (7 a and7 b). Reaction of7 b or6 d withTPP/DEAD/NH3 leads to 3,4-anhydro-2-azido-2-deoxy--D-galactopyranoside (8) and 3-azido-3-deoxy--D-altropyranoside (10), resp.The epoxide7 b is opened with NaN3/NH4Cl to the 4-azido-4-deoxymannosides (11 a and11 c) and the 3-azido-3-deoxy--D-idopyranoside (12), while the epoxide8 affords the 2,4-di-azido-2,4-dideoxy--D-glucopyranoside (9).Structures were elucidated by1H-NMR-analysis of the corresponding acetates.
H. H. Brandstetter undE. Zbiral, Helv., im Druck.  相似文献   

11.
The kinetics of oxidation of glycine and valine by chloramine-T in hydrochloric acid medium has been studied. The rate of disappearance of chloramine-T shows a first order dependence on both chloramine-T and the amino acid, and an inverse first order with respect to [H+]. The solvent isotope effect was studied using heavy water. The kinetic parameters,E a ,Arrhenius factorA, H and S and G have been calculated. A rate law in agreement with experimental results has been derived. A mechanism is proposed.
Über die Kinetik der Oxidation von Glycin und Valin mit Chloramin-T in salzsaurem Medium
Zusammenfassung Die Kinetik der Oxidation von Glycin und Valin mit Chloramin-T in Salzsäure wurde untersucht. Die Geschwindigkeitskonstante des Wegreagierens von Chloramin-T zeigt eine Abhängigkeit erster Ordnung sowohl von Chloramin-T als auch von der Aminosäure und ist invers erster Ordnung bezüglich [H+]. Der Lösungsmittel-Isotopeneffekt wurde mit D2O untersucht. Es wurden die kinetischen Parameter,E a , derArrhenius-FaktorA, H , S und G , bestimmt. Ein Mechanismus, der in Übereinstimmung mit den experimentenllen Daten ist, wird vorgeschlagen.
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12.
Isobaric expansibilities P and isothermal compressibilities T have been determined at 25 and 45°C for binary mixtures of ethylbenzene + n-tetradecane and + n-hexadecane and the corresponding excess functions (V E /T)P and (V E /P)T have also been obtained. With these data and supplementary literature values, the following second order mixing properties are also reported at 25°C: S E , (V E /P)T, CV and (VT). All mixing quantities have been compared with the results obtained at 25°C by using the Prigogine-Flory-Patterson theory of liquid mixtures. The predicted values suggest that the ability of ethylbenzene as a breaker of the pure n-Cn orientations is similar to what we found for toluene and higher than for p-xylene.  相似文献   

13.
Starting from (+) (2R) methyl 5-ethyl-2,2-spirobiindane-5-carboxylate of known enantiomeric purity 79 optically active, configurationally correlated 5,5,6-trisubstituted 2,2-spirobiindanes (2–7) were prepared for the purpose of testing a shortened polynomal Ansatz for chirality functions. Their optical rotations and1H-nmr spectra are reported.In this context several 6-substituted 5-ethylindanes (1) were prepared as model compounds for synthetic transformations.
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14.
Specimens of the system GeS x Se1–x were examined by means of X-ray and differential thermal analysis for 0x1. The activation energy of the specimens was calculated according to a semi-empirical method on the basis of the known thermodynamic parameters of the components.
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15.
Condensation of 1,1,2,2,-tetrabromomethylcyclopropane with 1,8-dihydroxynaphthalene yielded the (7.7.1)-type propellane. The peri effect on the reaction and the product conformation is discussed. As a result condensation of 1,1-dibromomethylcyclopropane withperi-dihydroxynaphthalene gives the diether-type compound2 instead of the expected spirane2.
Jamrozik, J., Propellanes III. J. für prakt. Chemie, im Druck (1980).  相似文献   

16.
Summary Crystals of (NH3OH)3GaF6 have been isolated from aqueous solution. The compound crystallizes triclinic, with cell parametersa=6.539(5) Å,b=6.924(5) Å,c=9.403(1) Å, =87.01(9)°, =83.98(8)°, =70.28(8)°. The thermal decomposition was studied by TG and DSC analysis.
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17.
Summary In contrast to hitherto published data, phenanthro[1,10,9,8,o,p,q,r,a]perylene-7,14-dione, the fundamental chromophoric system of hypericin type compounds, exhibits an absorption with a long wavelength band at 423 nm in aprotic solvents like dimethylsulfoxide (7000). Its fluorescence in these solvents is below the detection limit. In protic solvents like methanol, the long wavelength absorption is bathochromically shifted to 546 nm, and a fluorescence at 565 nm is observed. This behavior was interpreted from the reversal ofn – * and – * transitions. The data have not been recorded yet due to the very low solubility of this compound. Its monoprotonation in ground and excited states is characterized bypK a andpK* a values of –6 and 2; diprotonation occurs at apK a=–7.
Absorptions- und Emissions-Eigenschaften von Phenanthro[1,10,9,8,o,p,q,r,a]perylen-7,14-dion (Kurze Mitt.)
Zusammenfassung Im Gegensatz zu bislang publizierten Daten zeigt Phenanthro[1,10,9,8,o,p,q,r,a]perylen-7,14-dion, das fundamentale chromophore System der Hypericintyp-Verbindungen, in aprotischen Lösungsmitteln wie Dimethylsulfoxid eine Absorption mit einer langwelligen Bande bei 423 nm (7000). In diesen Lösungsmitteln ist Fluoreszenz nicht nachweisbar. In protischen Lösungsmitteln wie Methanol wird die langwellige Bande bathochrom verschoben (546 nm) und bei 565 nm tritt Fluoreszenz auf. Dieses Verhalten wurde mit der Umkehr in der Reihenfolge vonn – * und – * Übergängen interpretiert. Die Daten wurden wegen der extremen Schwerlöslichkeit dieser Verbindung bislang nicht erhalten. Die Monoprotonierung im Grund- und Anregungszustand ist durchpK a- undpK* a -Werte von –6 und 2 charakterisiert; die Diprotonierung tritt beipK a=–7 ein.
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18.
In the system U–La–N a new phase of composition La2U2N5 was observed. The differaction pattern of this phase can be indexed with a tetragonal unit cell:a=8.43 Å,c=8.50 Å andc/a=1.008. The pseudocubic sub-cell withaca/2 is closely related to the CsCl-type.
Auszug aus der von der Technisch-Naturwissenschaftlichen Fakuktät der TU Wien approbierten Diplomarbait des Herrn Dipl.-Ing.J. Waldhart.  相似文献   

19.
Summary A new method for the synthesis of 1,2-diaryl-1,2-dihydro-5-methyl-3H-pyrazol-3-ones3 and 4-acetyl-1,2-diaryl-1,2-dihydro-5-methyl-3H-pyrazol-3-ones5 is presented. The reaction of 4,4-disubstituted 1,2-diarylhydrazines1 with acetic anhydride in the presence of an equimolar amount of 4-(dimethylamino)pyridine leads to mixtures of the corresponding acetyl derivatives2 and3. Under the same conditions, 2,2-disubstituted 1,2-diarylhydrazines yield mixtures of3 and5.
4-(Dimethylamino)pyridin-katalysierte Reaktion von 1,2-Diarylhydrazinen mit Essigsäureanhydrid
Zusammenfassung Eine neue Methode zur Synthese von 1,2-Diaryl-1,2-dihydro-5-methyl-3H-pyrazol-3-onen3 und 4-Acetyl-1,2-diaryl-1,2-dihydro-5-methyl-3H-pyrazol-3-onen5 wird beschrieben. Die Reaktion von 4,4-disubstituierten 1,2-Diaryl-hydrazinen1 mit Essigsäureanhydrid führt in Gegenwart eines Äquivalentes 4-(Dimethylamino)pyridin zu Gemischen der entsprechenden Acetylderivate2 und3. Unter den gleichen Bedingungen werden aus 2,2-disubstituierten 1,2-Diarylhydrazinen Gemische aus3 und5 erhalten.
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20.
Reaction of the nitrile of 3,3-diphenyl-2-propenic acid with -branched nitriles in the presence of lithium amide in liquid ammonia does not give the correspondingMichael adducts but the ,-unsaturated nitriles6. Conc. sulfuric acid transforms these nitriles into the -lactones7.
Reaktion von 3,3-Diphenyl-2-propensäurenitril mit den Carbanionen einiger -verzweigter Nitrile (Kurze Mitteilung)
Zusammenfassung Die Reaktion von 3,3-Diphenyl-2-propensäurenitril mit -verzweigten Nitrilen in Gegenwart von Lithiumamid in flüssigem Ammoniak führt nicht zu den entsprechendenMichael-Addukten, sondern zu den ,-ungesättigten Nitrilen6. Durch Einwirkung von konz. Schwefelsäure entstehen aus diesen Nitrilen die -Lactone7.
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