Benzolactams. 4. Reaction of 3',4'- or 4',5'-dialkoxy-substituted 1-(2'-Bromobenzyl)-2-ethoxycarbonyl-1,2,3,4-tetrahydroisoquinolines with alkyllithium. 1,2 and 1,4 additions of alkyllithium to benzolactams

Treatment of 1-(2'-bromo-3',4'-dialkoxybenzyl)-1,2,3, 4-tetrahydroisoquinoline carbamates, 1a,c, with excess alkyllithium gave 8-oxoberbines, 2a,c, which were successively attacked in situ with another molecule of alkyllithium to give 1,2 and/or 1,4 addition products. A primary alkyllithium, such as MeLi or BuLi, gave a 1,2 addition product, 8-methyleneberbine 9a or 8-butylideneberbine 3a. t-BuLi preferred 1,4 addition, followed by elimination of the alkoxy group, to give 9-tert-butyl-8-oxoberbine 6a or 7c. s-BuLi gave a mixture of 1,2 and 1,4 addition products, 1-[2'-(2' '-methylbutyryl)benzyl]-1,2,3,4-tetrahydroisoquinoline 4a and 9-s-butyl-8-oxoberbine 5a. Similar treatments of carbamate 1b having no alkoxy group at its 3' position gave 1,2 addition products, 8-butylideneberbine 3b, 1-[2'-(2' '-methylbutyryl)benzyl]-1,2,3, 4-tetrahydroisoquinoline 4b, and 1-(2'-pivaloylbenzyl)-1,2,3, 4-tetrahydroisoquinoline 6b, in all cases. Reactions of 1a with s-BuMgCl and isoPrMgCl also gave the 1,4 adduct, 5a, and its 9-isoPr analogue, 12a. Treatment of 9a with excess NaBH(4) in AcOH gave (+/-)-coralydine (10b).     

The stability of silver iodide sols in the presence of polyacrylic acids of various molecular weights

Summary The effect of a series of polyacrylic acids, ranging in molecular weight from 1.67×10⁴ to 2.36×10⁶, on the stability of positively charged silver iodide particles has been examined. Flocculation of the sol occurred at a well defined concentration of polyacrylic acid,c _f , and a further increase in concentration of the polyelectrolyte caused restabilization of the sol. Over the range examinedc _f appeared to be related to the viscosity average molecular weight of the acid,M _v , by an equation of the form,c _f =a ·M _v ^{– b} wherea andb are constants.     

Action of photoreactivating light on pyrimidine heteroadduct in bacteria

Abstract— In stationary-phase Escherichia coli B/r, photoreactivation (PR) at 313 nm of ultraviolet (u.v.) killing is inefficient compared with PR at 405 nm, and can be explained solely by photoenzymatic reversal of pyrimidine dimers. In Staphylococcus epidermidis, PR shows a maximum at 313 nm, suggesting that this organism shows the Type III PR proposed by Jagger et al.[5] for Streptomyces strains. Reversal of pyrimidine dimers is not sufficient to explain this PR. The mechanism of Type III PR remains unknown. With both S. epidermidis and E. coli B/r, the amount of uracil–thymine heteroadduct in DNA hydrolysates decreases if the cells are given a post-u.v. treatment at 313 nm, but no decrease is observed if the post-u.v. treatment is at 405 nm. The biological significance of this adduct and of its removal is not clear. It may play a role in Type III PR.     

THE EFFECTS OF HOST-CELL REACTIVATION ON ASSAY OF U.V.-IRRADIATED HAEMOPHILUS INFLUENZAE TRANSFORMING DNA

Abstract— The host cell reactivation (HCR) mechanism in Haemophilus influenzae cells is inhibited by sub-microgram concentrations of acriflavine (as is already known to be true for Escherichia coli ). Exposure of these cells to similar concentrations of the drug during bacterial transformation increases the apparent ultraviolet light (u.v.) sensitivity of previously irradiated transforming DNA, indicating a repair of this DNA after uptake by the cells under normal conditions. Repair is inhibited by applying acriflavine at any time up to one hour after competent cells contact the irradiated transforming DNA. The fraction of the u.v. damage repaired by HCR is very different for different genetic markers. Those markers which are most u.v. sensitive when assayed in the absence of acriflavine are most poorly repaired, suggesting that this is the reason for their higher sensitivity. For all markers the fraction of the damage repairable by in vitro photoreactivation is approximately constant, and strongly overlaps the damage repairable by HCR. The degree of HCR achieved can be altered by experimental treatment of the H. influenzae DNA prior to transformation. Thus treatment of irradiated DNA with an enzyme from Micrococcus lysodeikticus –known to attack u.v. damaged, but not undamaged DNA–prevents subsequent intracellular repair of the same u.v. lesions whose repair is inhibited by acriflavine. Similarly, partial replacement of the thymine in transforming DNA by 5-bromouracil (BU) strongly inhibits repair of subsequent u.v. damage. As in bacteriophage, the BU effect is relieved if the u.v. exposure occurs in the presence of cysteamine. It is clear that intracellular repair must be considered in interpreting experiments with u.v.-irradiated transforming DNA.     

Austausch von Chrom(III) mit Chrom(II) und Szilard—Chalmers-Reaktion von Kaliumchromat

Zusammenfassung Durch Versuche mit⁵¹Cr wird gezeigt, daß Cr³⁺ mit Cr²⁺ austauscht, wenn man ein Chrom(III)-Salz in wässeriger Cr²⁺-Lösung auflöst, d. h. die Hydratation zum reaktionsträgen [Cr(H₂O)₆]³⁺ verläuft relativ langsam. Die Bedeutung dieses Austausches für dieSzilard—Chalmers-Reaktion von Chromat wird diskutiert.

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Experiments with⁵¹Cr prove the exchange of Cr³⁺ with Cr²⁺ when a Cr(III)-salt is dissolved in an aqueous solution of Cr²⁺. This indicates that the hydration to the inert [Cr(H₂O)₆]³⁺ is relatively slow. The importance of this exchange for theSzilard—Chalmers reaction of chromate is discussed.

     

Synthesis, band structure, and optical properties of Ba2ZnV2O8

A novel compound Ba₂ZnV₂O₈ has been synthesized in high temperature solution reaction and its crystal structure has been characterized by means of single crystal X-ray diffraction analysis. It crystallizes in monoclinic system and belongs to space group P2₁/c with a=7.9050(16), b=16.149(3), , β=90.49(3). It builds up from 1-D branchy chains of [ZnV₂O₈⁴⁻]_∞, and the Ba²⁺ cations are located in the space among these chains. The IR spectrum, ultraviolet-visible diffuse reflection integral spectrum and fluorescent spectra of this compound have been investigated. The calculated results of energy band structure by the density functional theory method show that the solid-state compound of Ba₂ZnV₂O₈ is an insulator with direct band gap of 3.48 eV. The calculated total and partial density of states indicate that the top valence bands are contributions from the mixings of O-2p, V-3d, and Zn-3d states and low conduction bands mostly originate from unoccupied antibonding states between the V-3d and O-2p states. The V-O bonds are mostly covalence characters and Zn-O bonds are mostly ionic interactions, and the ionic interaction strength is stronger between the Ba-O than between the Zn-O. The refractive index of n_x, n_y, and n_z is estimated to be 1.7453, 1.7469, and 1.7126, respectively, at wavelength of 1060 nm for Ba₂ZnV₂O₈ crystal.     

Untersuchung der Temperaturabhängigkeit derg ik -Tensoren von Polyäthyleneinkristallen

Zusammenfassung Es wurden die Kristallitgröße und die Änderungen der parakristallinen Gitterstörungen aus den Linienbreiten des Röntgenweitwinkeldiagramms von lösungskristallisiertem linearem Polyäthylen bei den Temperaturen 15°K, 73°K, 173°K und Zimmertemperatur bestimmt. Es wurde eine Zunahme der Gitterstörungen mit fallender Temperatur gefunden.

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Summary The crystallite size and the paracrystalline distortions in polyethylene single crystals were evaluated by the measurement of the linewidth in the X-ray wide angle diagram at four different temperatures (15°K, 73°K, 173°K and 297°K). An increase of the lattice distortions with decreasing temperature was found.

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Mit 3 Abbildungen

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Vorgetragen auf der Arbeitssitzung des Fachausschusses Physik der Hochpolymeren in der Frühjahrstagung 1970 des Regionalverbandes Hessen-Mittelrhein-Saar der Deutschen Physikalischen Gesellschaft in Darmstadt, 10.–13. März 1970.     

Über die Stereochemie der Hydrogenolyse von N-Benzyl-Bindungen I. Die Hydrogenolyse von Derivaten der 2-Amino-2-phenyl-propionsäure.

The stereochemistry of the hydrogenolysis of benzyl-N bonds was studied using S(+)-2-dimethylamino-2-phenyl-propionic acid (I) and its derivatives, and R(?)-2-anilino-2-phenyl-propionic acid (II). The configuration of I was confirmed, that of II established by ORD. measurements, after transformation of the phenyl into cyclohexyl groups. On a palladium catalyst the hydrogenolysis of I, its methyl and ethyl esters and its amide proceeded with 72 to 99% inversion of configuration, that of II with at least 66% inversion. The ester of the quaternary ammonium derivative of I gave as much inversion as retention (= racemisation).     

The effect of metal oxides on the oxidation of polybutadiene

Carboxy-terminated polybutadiene (CTPB) was oxidised as a coating on various metal oxides by heating in air on a thermobalance. The oxidation was found to be free from diffusion control and was catalysed by certain of the oxides. The catalysis was shown to be independent of semiconductor type and to be associated with those oxides for which the width of the forbidden zone between the valence and conduction bands (U) is less than 1.9 eV. In general, low values of U result in high catalytic activity. It is proposed that catalysis occurs by a redox mechanism, viz. RO₂H + p → RO₂^. + H⁺, RO₂H + e → RO^. + OH^?.     

Thermal density fluctuations in amorphous polymers as revealed by small angle X-ray diffraction

Summary Thermal density fluctuations in amorphous polymethyl methacrylate, polycarbonate and polyethylene terephthalate were studied by means of small angle X-ray scattering. The measurements were performed in a temperature range from 20 °C up to about 50 °C above the glass transition temperatureT _g of the individual sample.AboveT _g the experimental values of the fluctuations are proportional to the isothermal compressibility and the temperature of the sample as predicted by the fluctuation theory for a system in thermodynamic equilibrium.At temperatures belowT _g this relation is no longer correct. The experimentally determined fluctuations are now proportional to the compressibility of the sample in the equilibrium state atT _g and to the actual temperature of the glassy sample. By considering a statistical ensemble with exchange of energy, particles and order between the systems of the ensemble an equation can be derived for the fluctuations of the number of particles per given volume which predicts the observed behaviour. The order parameter takes into account the fact that the properties of the glassy state depend on the way by which the state was produced.

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Zusammenfassung Es wurden thermische Dichtefluktuationen in amorphem Polymethylmethacrylat, Polycarbonat und Polyäthylenterephthalat mit Hilfe der Röntgenkleinwinkelstreuung untersucht. Die Messungen erstrecken sich über einen Temperaturbereich von 20 °C bis zu etwa 50 °C oberhalb der GlastemperaturT _g der jeweiligen Probe.In Übereinstimmung mit den Ergebnissen der Fluktuationstheorie sind die Fluktuationen oberhalb vonT _g proportional zur isothermen Kompressibilität und zur Temperatur der Probe.Unterhalb der Glastemperatur ist diese Beziehung nicht mehr erfüllt. Hier ist die Fluktuation proportional zur Kompressibilität der Probe im Gleichgewichtszustand beiT _g und zur Temperatur. Auf der Basis einer statistischen Gesamtheit mit der Austauschmöglichkeit von Energie, Partikel und Ordnung zwischen den Systemen der Gesamtheit kann eine Beziehung für die Dichtefluktuation abgeleitet werden, die mit den experimentellen Ergebnissen übereinstimmt. Der zusätzliche Ordnungsparameter berücksichtigt die Tatsache, daß die Eigenschaften im Glaszustand wegabhängig sind.