ALBERT

Notes: Summary The relation of melt viscosity to weight-average molecular weight and branching index has been derived for polydisperse polymers, with the most probable distribution of primary chains, having randomly distributed tri- or tetrafunctional branch points. The results are obtained by an extension of theKilb treatment for the intrinsic viscosity calculations. Numerical values of the viscosity functions are given for selected branching indices.

Notes: Summary A new calculation of the stability of elongational flow of a liquid filament is based on an idealized treatment of the effects of non-uniformity of filament diameter. Two uniform cylindrical filaments of different initial cross-sectional areas are connected by a fictitious deformable clamp which transmits tensile force without interfering with the assumed homogeneous elongational flow of each filament. A uniform tensile force is suddenly applied and kept constant. For a Newtonian liquid, the area ratio rapidly tends to infinity. For a “rubberlike liquid”, the area ratio at first increases but then becomes constant; this suggests that finite deformation of a “Gaussian” molecular network may provide a possible mechanism for “spinnability” at constant temperature and composition.

Notes: Summary The rheological characteristics of synovial fluid have been examined with aWeissenberg Rheogoniometer. Rheological evidence for the existence of a macromolecular complex in normal but not in inflammatory joint fluids has been deduced from experiments with hydrogen bond breaking agents. Further flow experiments with measurements of relaxation time and activation energy for viscous flow appear to support the contention that macromolecular complexes do exist in normal fluid and that dilution alone does not account for their dissolution in inflammatory joint diseases. Proteolytic enzyme extracts from inflammatory synovial fluid appear to have no effect on the flow characteristics of normal synovial fluid. Attempts to identify the nature of the macromolecular complex by analytical ultracentrifugation were not successful. It is concluded that rheological techniques offer a way of investigating macromolecular interactions when classical chemical methods may not be appropriate.

Notes: Conclusion The effect of mechanical working on polyethylene oxide suggests that, although this substance fulfils many of the criteria for an artificial lubricant in human joints, it is unlikely to be successful in vivo over a prolonged period. This is probably due to the weak linkages present. The simplicity of the structure might have led one to think that it would withstand mechanical degradation more satisfactorily than a more complex molecule, but the experiments demonstrate that this is not so. Sodium carboxymethyl cellulose, on the other hand, shows a high degree of resistance to mechanical degradation and a successful artificial lubricant is likely to be closer to this configuration in which bonds are less exposed.

Notes: Zusammenfassung Die Änderung der Viskosität von nativem Blut in Abhängigkeit von Zeit und Druck in einem Kapillarviskosimeter folgen einem bestimmten Schema: bei gesunden Versuchspersonen folgt einem starken Abfall ein Anstieg, bevor die Gerinnung einsetzt. Derartige Untersuchungen sind auch an Blutproben von Patienten, die an gewissen seltenen Krankheiten leiden, besonders solchen mit Mangel an Gerinnungsfaktoren, gemacht worden. Die erhaltenen Beziehungen entsprechen nicht dem normalen Verlauf. Da jedoch zu wenig Patienten zur Verfügung standen, ist es jedoch schwer zu sagen, ob diese Abweichungen für diese Krankheiten typisch sind. An Multiple Sklerose Erkrankten sind genügend Untersuchungen durchgeführt worden. Es ist wahrscheinlich, daß für diese Krankheit ein eigenartig systemloses Verhalten typisch ist. Dieses ist anscheinend unabhängig von der betreffenden Therapie. Es stellt sich nicht ein, wenn es zu schweren Komplikationen im Krankheitsverlauf gekommen ist. Dieser Test ist aber nicht genügend empfindlich für die Frühdiagnose. Nach Beginn der Gerinnung folgen alle normalen und pathologischen Zustände derselben Gleichung für die Gerinnungskinetik, aber natürlich nicht mit denselben Gleichungskonstanten.

Notes: Summary Stiffness is an important subjective phenomenon diagnostically and therapeutically in rheumatic diseases such as rheumatoid arthritis and osteoarthrosis. A quantitative and qualitative assessment of these phenomena have been made by arthrographs which impose a sinusoidal motion on the metacarpo-phalangeal and knee joints respectively and record the torque in relation to the displacement. The reproducibility with the joint in situ and moved is satisfactory. A hysteresis torque/ displacement plot is obtained with both joints. Reflex muscle activity may be measured at the joint, as in myotonia congenita and Parkinsonism. In patients without neuromuscular disorders electromyographic studies have shown that the muscles are electrically silent during sinusoidal motion and that active contraction distorts the tracing. The latter fact may be useful in the evaluation of patients with psychological factors producing muscle tension, which may be decreased with diazepam. Using the cat's wrist joint it has been shown that the passive stretching of muscles accounts for 41 per cent of the stiffness recorded at the joint and the capsule 47 per cent, a finding in keeping with work on the distal interphalangeal joint of the human finger. Stiffness increases with advancing age and decreased temperature. Conversely, warming the joint reduces its stiffness. Articular gelling in patients with osteoarthrosis may be demonstrated after periods of rest and the results suggest that such changes are due to alterations in the periarticular and muscle tissues. The rapid diminution in torque after rest in one position was not detected in normal joints even after longer periods of immobilisation.

Notes: Zusammenfassung Eine Kontinuumstheorie ist kürzlich entwickelt worden, die erwarten läßt, die Eigenschaften der flüssigen Kristalle zu beschreiben. Der Zweck dieser Arbeit ist es, erstens, diese Theorie vorzustellen, und, zweitens, ihre Anwendung auf die Viskosimetrie der nematischen flüssigen Kristalle zu diskutieren. Oftmals benutzt man magnetische Felder in den umfangreichen Experimenten, um die Orientierung der bevorzugten Richtung zu kontrollieren, und daher ist eine Diskussion dieses Falles eingeschlossen.

Notes: Summary The formulation of oil-in-water emulsions which have the mechanical properties of semi-solids, i. e. creams, involves both theoretical and practical problems. One solution is to use combinations of ionic or non-ionic surfactants with a fatty alcohol, as in Emulsifying Wax B. P., Cetrimide Emulsifying Wax B. P. C. and Cetomacrogol Emulsifying Wax B. P. C. By altering the total amount of such a mixed emulsifier in a formulation, the consistency may be varied from liquid to semi-solid. The rheological properties of such emulsions have been explained on the assumption that a viscoelastie network exists in the continuous phase, linking disperse phase globules. The nature, extent and strength of this network controls the flow properties of the system. This theory is discussed with particular reference to the anionic surfactant sodium dodecyl sulphate, the cationic surfactant cetrimide, and the long chain alcohols cetyl and stearyl and their mixtures. The importance of testing at small strains is emphasised e. g. creep and oscillatory testing, and it is shown that continuous shear methods, although theoretically less satisfactory, may also provide useful information.

Notes: Summary The physical decomposition of the system formed when sodium dodecyl sulphate, 1-hexadecanol and water are heated, mixed and cooled could be achieved at an accelerated rate by cycling the storage temperature between 5–7 °C and 20–25 °C. This decomposition caused the formation of “pearliness” and the systems became progressively more fluid with loss in rigidity. The changes in the rheological properties of the systems were investigated at 25 °C using a modifiedWeissenberg Rheogoniometer, anEpprecht Rheomat 15 viscometer, and a concentric cylinder air turbine viscometer. The systems are referred to by a code Rx where x is the molar ratio of 1-hexadecanol to sodium dodecyl sulphate. The systems R1–R10 were examined during temperature cycling for a maximum period of eight days. During this period, the systems R1–R4 progressively increased in consistency when examined in continuous shear using anEpprecht Rheomat 15, concentric cylinder viscometer. System R5 was also examined using anEpprecht Rheomat 15, but after increasing in consistency up to the fourth day, thereafter decreased in consistency. Systems R3 to R10 were investigated in creep mode. For R3 and R4, the compliance progressively decreased over a period of eight days, whereas for systems R5–R8 compliance was found to pass through a minimum about four days after preparation and the start of temperature cycling. Thereafter it increased. For R9 and R10, the creep compliance at one hour increased continuously during the eight day period.

Notes: Summary The theory ofEyring of viscous flow, allows to describe the newtonian surface viscosity of a monolayer containing only one active component. This theory is extended to mixed monolayers with miscible components, allowing to calculate the surface viscosity of a surface mixture if the flow parameters of the single components are known. This theory is experimentally illustrated for the systems senegin/digitonin and cholesterol/phospholipids. The results of the last system are discussed in terms of the property of cholesterol being a liquifier in cell membranes. Next the surface viscosities of dilute cholesterol monolayers penetrated by digitonin are given. In this situation no agreement between theory and experiment is observed, indicating an interaction between these components as already known from other experimental techniques. This increased surface viscosity may be related to the strong hemolytic action of digitonin.

Notes: Summary The stability of oil-in-water emulsions depends ultimately on the physical nature of the oil-water interface. If a hydrocolloid or protein is used as an emulsifying agent an interfacial film is formed at the oil-water interface and this may be liquid or viscoelastic solid in properties. The film is formed by the two processes of diffusion from the bulk to the interface and the formation of secondary intermolecular cross-links. Gelatine solutions of up to 2% w/v were used to form an interface with light liquid paraffin over a restricted range of p h . For the 2% w/v gelatin solutions, the p h range was confined to the acid region p h 2.5–3.2 owing to the onset of gelation of the whole aqueous phase, at room temperature, if the p h was increased numerically above this range. At lower concentrations of gelatin, e. g., 0.5% w/v, the useful p h range could be extended to p h 4. The interfacial rheological properties were examined using the surface rheometer described in a previous paper. Preliminary results showed that, in the case of the 1% w/v gelatin solution at p h 3, the interfacial film was liquid up to the end of the first half-hour after formation. Solid properties then developed. After 4 hs it was possible to carry out a creep experiment on the film which exhibited a longest retardation time of several minutes. Further creep and recovery experiments conducted up to 200 h after the formation of the film clearly showed that the growth of solid properties of the film was continuing. The gelatin interfacial films were considerably more compliant than similar films of acacia Senegal, over a comparative period of time, and at the same bulk concentration. This difference in behaviour can be attributed to differences in the basic molecular structure of the two polymers.

Notes: Abstract The pressure dependencedT g /dP of glass transition temperatureT g has received considerable interest due to its connection with solid state thermodynamic properties and theories of glass transition. Free volume considerations (1, 2) led to an estimate of the pressure effect onT g , showing thatdT g /dP had to depend on thermal expansion and compressibility changes atT g through the equation: [1] $$\frac{{dT_g }}{{dP}} = \frac{{\Delta \beta }}{{\Delta \alpha }}$$ whereΔβ=β e −β g andΔα=α e −α g Later work (3, 4, 5, 6) has shown that eq. [1] is not verified by experimental facts, the ratioΔβ/Δα being much larger than (dT g /dP) exp. Recent analysis of the properties of glasses obtained under different pressures have complicated the situation, showing that the experimental value ofdT g /dP depends, of course, on the polymer usedbut also on the experimental procedure used in its determination. Since it is obvious that in order to measure anyΔT g -value we need to operate on at leasttwo glasses, these should be identical in all properties which could influenceT g except pressure. Any difference in morphology,which could lead to a change in T g at constant pressure, should therefore be avoided in order to get a sound value for the pure pressure effectdT g /dP. To reveal this effect, we have performed (7)dT g /dP determinations on two polymers, polyvinylacetate (PVAC) and polyvinylchloride (PVC), following three different procedures: A. Measurement of the changeΔT g induced by application of a pressure incrementΔP on the liquid polymer (T〉T g ). This is the procedure normally used; the liquid is cooled down at a fixed rate of temperature change (∼5 °C/day) andT g is dilatometrically recorded at 1 atmosphere. Then the polymer is taken again to the liquid state, pressure ΔP is applied and, at the same rate, the system is cooled down isobarically; the newT g is recorded anddT g /dP calculated. B. Measurement of the change ΔTg induced by application of a pressure increment ΔP on the glassy polymer (T〈T g ). Once determinedT g at 1 atmosphere, pressureΔP is applied on the glass, time is given to the system to equilibrate; then the glass is heated isobarically. Intersection of the glassy line to the liquid line in a volume/temperature plot gives the newT g and therefore allows the calculation ofdT g /dP. C. Measurement ofΔT g during the heating of a glass along an isochor (5, 8). Here the polymer glass is heated at constant volume, by application of an increasing pressure at increasing temperatures given by(∂P/∂T) v . By repeating this procedure two times, starting from two different specific volumes of the glass, two values ofT g at different pressures can be recorded anddT g /dP calculated. Table 1 shows the result of this work Polymer A dT g /dP, °C/atm B C PVAC 0.015 0.037 0.022 PVC 0.013 0.038 0.028 Comparison of values for different procedures shows quite convincingly howdT g /dP, at a given heating or cooling rate, is a property not only of the polymer but also of the experiment. Any information which, like the pressure effect onT g , is based on a comparison between two or more glasses, should be therefore carefully analysed in terms of other contributions, besides pressure, to the total change inT g .

Notes: Abstract The temperature-dependence of the viscosity η of a liquid can be described by means of an empirical equation suggested as early as 1921 byVogel: η=A exp.B/(T−T 0), which, besides the temperatureT, contains three adjustable structuredependent parametersA, B andT 0. An equation of the same form is suited for describing the temperature dependence of the most probable relaxation timeτ m in polymers, and can be easily transformed into the socalled WLF-equation, because the empirical parametersB andT 0 are simple functions of the WLF parameters. In many cases, the temperature-dependence of such quantities as mechanical or dielectric relaxation times, viscosities, diffusion coefficients etc, is regarded as a consequence of a thermal activation process ruled by a temperature-dependentGibbs Free Energy of activationΔG. On the basis of this concept both parametersB andT 0, can be related to the more fundamental high temperature limiting value of the activation energyΔH and the parameterT 0 to the temperature at whichΔG becomes infinite. The parameterA is normally taken to be temperature-independent; theoretically, however, it may just as well be temperature-dependent. Although it is difficult to decide from experimental evidence whether this is the case (accurate values over a large temperature range must be available), one should realize that analysis done by means of a temperature-independent pre-exponential factor gives a set of values for the parameters which differ greatly from those found when e.g.A is set proportional toT −1 orT −2. Literature values for the viscosities ofn-paraffins have been statistically analysed. It is concluded that η in theVogel-equation had better be replaced byη T 1.2/ϱ, whereϱ is the density of the liquid. Values are given for the modifiedVogel, WLF and activation parameters of the paraffins and ethylenecopolymers, those for the latter being obtained from our own dielectricτ m measurements. By analogy,τ m would then have to be replaced byτ m T 2.2. However with our dielectric data, such a refinement would not give any great improvement.

Notes: Abstract Since long it is settled that the elasticity of rubber must be attributed to the statistics of the polymer coils. The molecular basis of visco-elasticity, however, remained mysterious and is still considered by many as a complicated problem. In the first years after World War II phenomenological descriptions by means of models composed of springs and dashpots were popular but these models, and also their mathematical transcriptions intoLaplace series, are highly unsatisfactory (restriction to very small deformations, relaxation and retardation spectra, impossibility to account for the cross contractions connected with uniaxial strain, etc.). In the past years several attempts have been made to interprete the spring-dashpot model in terms of molecular structure. The springs have been identified with the entropy elasticity of the polymer coils and the dashpots with an intermolecular friction coefficient. Even if it is assumed that this interpretation should be justified then it is a matter of course that such a theory is afflicted with the same absurdities and frustrations as the spring-dashpot model itself. The necessity of another approach will be urged. As rubber elasticity, which refers always to equilibrium states, is an effect of changes of the reversible entropy, so the viscoelasticity of transient states is effected by changes of the irreversible entropy. The transformation of irreversible elastic energy into heat is essentially an increase of entropy and the rate of this process is entirely determined by the probability of the various states because probability of a state and life time of a state are identical expressions. The introduction of a molecular friction is a misconception.

Notes: Zusammenfassung Die Rolle der Struktur-Theorie des Theologischen Verhaltens nichtlinearer visko-elastischer Flüssigkeiten wurde diskutiert, und es wird eine solche Strukturtheorie für. verschiedene Polymer-Systeme angegeben.

Notes: Summary In continuation of an earlier investigation, the present paper discusses the stress distribution in the inertialess flow of a viscoelastic fluid confined between two plane parallel walls, in which the upper wall moves with a constant velocity while the lower is held at rest with a uniform constant suction applied on its surface. However, the stress field is discussed in detail for the case when the upper wall is also held at rest and the effects arising due to application of suction are pointed out. The most important difference in the behaviour of viscoelastic fluid, compared with that ofNewtonian fluid, lies in the fact that the gradient of the normal stress component in the horizontal direction depends on the distance from the walls. A short discussion has also been provided for the flow in a cylindrical tube with uniform constant suction applied on its surface. Though not evident from general considerations, it is seen that the situation here also is quite similar to that of plane flow.

Notes: Zusammenfassung Die dynamischen Eigenschaften eines Styrol-Butadien-Copolymers und eines Naturkautschuks sind als Funktion einer statischen Vorverstreckung gemessen worden. Die dynamische Viskositätη dieser Polymeren ändert sich nicht bis zu einer statischen Verstreckung von ca. 1,7, und die dynamische Spannungsamplitude ist der Steigung der statischen Spannungs-Dehnungs-Kurve proportional. Der Tangens des Verlustwinkels hängt nicht nur von der dynamischen Viskosität, sondern auch von der dynamischen Spannungsamplitude ab. Er ist deswegen nicht unbedingt von einer statischen Verstreckung unabhängig, wenn auchη konstant ist.

Notes: Summary Excess charges in negatively ionized membranes carried by the mass movement were determined experimentally from the data of electroosmosis and streaming potential for systems of collodion based polystyrene sulfonic acid membrane in KC1 solutions. The charge density effective to the mass movement in the membrane was found to be several percent of the stoichiometric density of charges fixed on the polyelectrolyte skeletons constituting the membrane. From this value together with the experimental data of the hydraulic permeability of the same membrane-electrolyte system, the effects of mass movement on the membrane potential and on the permeability of the electrolyte component were evaluated to be a few percent for the membrane potential and less than ten percent for salt permeability, respectively. Thus the mobilities of co- and counter-ions in charged membrane determined from the data of membrane potential and salt permeability of the membrane, as reported in Part I of this series, may be valid within ten percent. This was confirmed by comparing the experimental and theoretical values of the DC conductance for the membranes in various KC1 concentrations of the external solution.

Notes: Summary Theγ-irradiation of nylon-6 film in the presence of aqueous acrylic acid and cupric chloride at constant concentrations has been studied at different radiation intensities,I, and the following relationships found:R H ∞I 1.0 andR G ∞I 0.7. Here,R H andR G denote the initial rates of homopolymerisation and grafting respectively. The values of the exponents, 1.0 and 0.7, indicate that in homopolymerisation the termination is mainly by cupric ions, whereas in grafting there is a mixed form of termination, viz. by cupric ions and by bimolecular reaction between growing chains. Experiments have been conducted on the influence of film thickness, the rates of swelling of grafted and ungrafted films and the effect of regrafting to grafted films. The results show that a fast rate of grafting ac companied by a slower rate of monomer diffusion does not prevail in this system, and hence it is not a contributory factor to the fall-off observed in the grafting curves.

Notes: Zusammenfassung Die Wechselwirkung zwischen Polyvinylpyrrolidon (PVP) und dem Gemisch zweier Tensiden im wässerigen System wurde viskosimetrisch bei folgenden fünf typischen Paaren der Tenside in drei Kategorien untersucht, in welchen in jeder einzelnen Lösung das erstgenannte Tensid der Kombination eine starke Wechselwirkung mit PVP aufweist und das zweite dagegen, außer Guanidinium-Dodecylsulfat, gar keine oder nur eine schwache ist. 1. Verschiedene Tensidionen mit gleichen Gegenionen: Natrium-Dodecylsulfat (NaDS) und Natrium-Decylsulfat. 2. Gleiche Tensidionen mit verschiedenen Gegenionen: NaDS und Tetrabutylammonium-Dodecylsulfat; NaDS und Guandinium-Dodecylsulfat; Dodecylammonium-Thiocyanat (DASCN) und Dodecylammonium-Chlorid. 3. Ein ionisches und ein nichtionisches Tensid: NaDS oder DASCN und Polyoxyäthylendodecyläther. Die Kombinationen geben mit PVP mannigfaltige Wechselwirkungen, und die Neigungen wurden aus den Beziehungen von Tensid-Tensid und Polymer-Tensid und aus der Gegenionverteilung um den Polymer-Tensidkomplex diskutiert.

Notes: Zusammenfassung In wäßrigen Suspensionen zeigen hydrophile Aerosiltypen (Aerosil 200, 130, Ox 50) ein qualitativ ähnliches Sorptionsverhalten gegenüber kationischen Tensiden. Das Ausmaß der Bindung wird von der spezifischen Oberfläche des Aerosils bestimmt. Eine Wechselwirkung mit anionischen Tensiden kann an hydrophilem Aerosil nicht festgestellt werden. Dagegen adsorbiert hydrophobes Aerosil R972 sowohl anionische als auch kationische Tenside. Die den Sorptionsvorgängen an kolloider Kieselsäure zugrunde liegenden Mechanismen werden, ausgehend von den Oberfläeheneigenschaften der Aerosile und dem kolloidchemischen Verhalten der ionogenen Tenside diskutiert. Die sorptionssteigernde Wirkung von Elektrolyten findet dabei besondere Berücksichtigung.

Notes: Summary From measurements of electrocapillarity at oil-water interfaces, interfacial isoeleetric points, pHi * of phosphatidyl choline (PC), sphingomyeline (SM) and phosphatidyl ethanolamine (PE) were obtained as functions of the electrolyte concentration in the aqueous solutions. In the case of 10−4 M KNO3 the isoelectric point of PC was 3.3, which was in good agreement with that obtained from the electrophoresis of O/W type emulsions. The limiting values of pHi * at low electrolyte concentrations were characteristic to the lipids. They were 3.1, 2.3 and 1.4 for PC, SM and PE, respectively. The pHi * was influenced by the cationic species in the aqueous phase. For instance, for PC or SM it decreased with increasing Th4+ ion concentration. While, in the case of PE, an opposite tendency was observed. The former effect was explained by the adsorption of the Th4+ ion at the interface, thus increasing the interfacial potential. While, the latter could be ascribed to the competition between the hydrogen and metal ions for the phosphate sites of adsorbed lipid molecules.

Notes: Zusammenfassung Mit Hilfe der Paramagnetsondemethode wurden Strukturumwandlungen im System Tween-80-Wasser und Natriumdodecylsulfat-Wasser untersucht. Die Änderung der Relaxationszeit wird mit der Änderung der Makroeigenschaften des Systems verglichen.

Notes: Summary Membrane potentials across parchment supported manganese ferrocyanide membrane for various electrolytes over a wide concentration range have been studied. It was found that the membrane potential increases with dilution of the external electrolyte solutions. The fixed charge density of the membrane has been evaluated byAltug andHair's method and comes out to be −0.06 N. The variation of the transport number of the counterions in the membrane phase and perm-selectivity of the membrane with dilution have also been studied.

Notes: Abstract The kinetics of the silver (I)/silver (II) couple have been studied in 3 M nitric acid and 3 M perchloric acid at a platinum electrode. It has been found that silver (II) can be produced in high current yields in a fast electrode reaction although the conversion of silver (I) to silver (II) is limited by the chemical reaction of silver (II) with water. It has also been shown that silver (I) can successfully be used as a catalyst or ‘current carrier’ in the anodic oxidation of organic and inorganic substrates.

Notes: Abstract An adiabatic calorimeter was used to measure the thermodynamics of the silver zinc cell. The charge and discharge reactions were shown to take place in two stages involving the production of argentous oxide and argentic oxide respectively. No thermal evidence was found to suggest the existence of a higher oxide of silver. The cell reactions were (1) $$2{\text{Ag + ZnO}} \leftrightharpoons {\text{Ag}}_{\text{2}} {\text{O + Zn, }}\Delta {\text{H = 158}} \cdot {\text{7 kJF}}^{ - {\text{1}}}$$ (2) $${\text{Ag}}_{\text{2}} {\text{O + ZnO}} \leftrightharpoons {\text{Ag}}_{\text{2}} {\text{O}}_{\text{2}} {\text{ + Zn, }}\Delta {\text{H = 176}} \cdot 1{\text{ kJF}}^{ - {\text{1}}}$$ If the cell was left on open circuit for a long period, or the positive electrodes heated, reaction (2) was suppressed and the discharge took place via reaction (1), without any reduction in capacity.

Notes: Abstract Electrodeposited manganese dioxide is finding increasing use as the cathode in high performance Leclanché cells. In this study a number of commercial and pilot plant materials together with experimental variants were examined in Leclanché R.20 size cells and found to have widely different performances on a simulated motor discharge. The initial X-ray diffraction diagrams of the manganese dioxides, viewed in order of decreasing discharge performance, show a gradual diminution of theγ phase peak and the emergence of aβ phase peak. X-ray diffraction thus provides a means of recognizing a preferred electrodeposited manganese dioxide for the simulated motor discharge.

Notes: Abstract Molten bisulphates form an interesting class of low-temperature fused salts which quench to form glasses; some technical and theoretical applications of these systems are discussed. The NaHSO4KHSO-4 eutectic (46.5% KHSO4, m.p. 125°C,T g 25°C) is easy to study since at lower temperatures decomposition of the melt is retarded and supercooling readily occurs. The solvent properties of this eutectic towards both inorganic and organic solutes have been investigated. The oxidation states available to transition and post-transition metals were studied spectrophotometrically and voltametrically; the results show a very restricted pattern of redox chemistry. The (abbreviated) electrochemical series is V(V)/V(IV)〉Mn(III)/Mn(II)〉H(I)/H2(O)〉Ag(I)/Ag(O)〉Mo(VI)/Mo(V)〉 Hg(I)/Hg(O)〉Cu(II)/Cu(O)〉Zn(II)/Zn(O). The Hammett acidity function,H 0, was measured as in the range −1 to −2. Various factors influencing redox reactions in the melt are discussed.

Notes: Abstract In this paper, electrochemical oxidation of glucose at the concentration level present in human venous plasma is discussed, with the object of determining the feasibility of constructing an implantable fuel cell for powering a prosthetic heart. The model anode considered consists of a diffusing membrane, to prevent blood contact, backed by a porous electrode structure. The latter is assumed to consist of parallel tubular pores of length equal to the electrode thickness. The variation of membrane and electrode parameters and rate constants for glucose oxidation are considered as functions of reaction order and oxidation product under different flow conditions. It is shown that the least optimistic case, oxidation of glucose only to gluconic acid, is apparently marginally feasible.

Notes: Abstract The effective resistivity of the discontinuous metal phase in a fluidized bed copper electrode is derived from measurements of the potential distribution in the solution. The values are similar to those which have been previously observed for a fluidized bed of silver-coated particles and are compared with a theoretical expression based on a model of charge sharing during single particle elastic collisions. It is shown that the metal resistivity follows the predicted dependence on bed expansion and solution resistivity; the constant of proportionality is, however, different and this is attributed to a stagnation zone close to the feeder electrode. Such a stagnant zone is also indicated by comparison of the experimental and theoretically predicted distribution of potential in the metal phase. The diffusion controlled removal of copper from 10−4 M copper sulphate is also shown to follow the theoretically predicted behaviour; the mass transfer coefficient indicates a high degree of turbulence within the bed. It is shown that scale-up factors of the order of 300 can be achieved in the processing of such dilute solutions. In view of the relatively high resistivity of the metal phase it is suggested that practical systems would arrange for a current and fluid flow to be at right angles to each other.

Notes: Abstract Consideration is given to four alternativein situ methods of determining the area of a dropping mercury electrode. These methods are particularly relevant to those conditions where ordinary calibration procedures are not possible, for example, in closed systems at elevated pressures and temperatures.

Notes: Abstract The rotating disk electrode has been used for the study of the electroless nickel plating from an acid bath strongly buffered by acetate. The variations of the mixed potential with the temperature have been investigated, and explained by means of polarization curves. These latter present an anodic peak which is typical of the electroless nickel deposition. The polarization resistance measurements allow a direct determination of the plating rate. All these experiments, related to mechanical measurements of plating rate, show the important inhibitor effect of the dissolved oxygen on the deposition reaction. The preliminary study of the faradaic impedance of the metal-electrolyte interface shows that the deposit occurs with not less than two heterogeneous steps, involving an adsorbed intermediate species, which could be NiOHads.

Notes: Abstract The passivation of horizontal and vertical porous zinc (unamalgamated) electrodes in aqueous KOH solutions has been studied. The results are interpreted in terms of the formation of a soluble anodic product which decomposes within the electrode forming an insoluble deposit. The ohmic resistance of the insoluble anodic product provides the major component of the electrode polarization and determines the useful duration of discharge of the electrode.

Notes: Abstract Data so far published on the thermodynamics of sodium amalgams and chloride solutions allow us to calculate the reversible potential for the electrolysis of brines at concentrations and temperatures corresponding to industrial processing. Data are also reported for the electrolysis of hydrochloric acid solutions. Kinetics of chlorine discharge and passivation phenomena on Pt, Pt-Ir and oxide-based electrodes are reviewed, in relation to the use of dimensionally stable electrodes, on titanium supports. The electronic conduction of RuO2 and other oxides is also discussed.

Notes: Abstract A new method of recovering chlorine from by-product hydrogen chloride is proposed and developed. Hydrogen chloride gas is led through a carbon pipe to a gas diffusion-type porous carbon cathode, which is immersed in a molten salt of lithium chloride (58 mol%)-potassium chloride (42 mol%) at 400°C. A graphite anode is immersed in the same electrolyte. By the direct electrolysis of gaseous hydrogen chloride, hydrogen is obtained from the cathode and chlorine is obtained from the anode. Bench scale tests were also carried out. The current capacity of the cell is 20 A. The cell voltage is 4.9 V at 20 A (500°C, electrode distance 3.8 cm) and in this case, more than 65% of it is the ohmic loss. Current efficiency is more than 90%. It can be concluded that this method is very promising.

Notes: Abstract The decomposition voltage on 75 kA aluminium reduction cells with Søderberg anodes was measured by extrapolation of current-voltage curves and by use of an aluminium reference electrode. Both methods yielded results in the range 1.50 V–1.85 V, although higher and lower values occasionally occurred. The anode-reference voltage as well as the cell voltage showed a marked increase when the alumina content in the bath decreased below 2 wt%, and the anode effect was approached. This behaviour is in good agreement with theoretical curves based on laboratory data on anodic over-voltage and electrical conductivity.

Notes: Abstract Two integration procedures for improving the precision of a.c. polarography have been studied. Both methods are single electrode techniques and involve integration of the rectified a.c. current over the complete peak or at the peak potential respectively. The time integration procedure was found to be seriously influenced by small variations in the reference electrode potential and applied voltage, resulting in poor reproducibility between different samples. In the area integration procedure, however, where the accurate control of potential is less critical, the standard deviation between replicate samples was found to be within the statistically expected limits and this method was therefore preferred. Standard deviations were measured for a range of inorganic and organic species and typical values of ±0.25% at the optimum concentration level (4.10−4M) were obtained.

Notes: Abstract The ‘Norbide’ boron carbide electrode has been satisfactorily applied to polarographic studies of Pd(II)−Pd° and some other systems involving deposition of metal. By its means the following thermodynamic and kinetic data have been established: standard oxidation-reduction potentials, Pd2+−Pd°, 0.91 V; Ag+−Ag°, 0.805 V; stability constants, PdCl 4 2− , logβ 4, 9·38; logK 4, 1·44; Pd(SO4) 2 2− , log β2, 3·16; activation energies, Pd2+−Pd°:Q D, 18·6; Q°, 188 kJ mole−1. Analytical applications have been briefly examined.

Notes: Abstract Experiments have been carried out on the deposition of copper and zinc by imposing pulsating cathodic overpotentials of varying frequency on the electrodes. In the potential region, where the resulting currents were large enough to produce complete concentration polarization at the electrode, it was shown that at very low frequency (t~10 cps) deposits exhibited surface roughness increasing with time in a manner similar to that seen in d.c. deposition. With increasing frequency an ever smoother deposit was obtained, and at high frequencies (≈ 10,000 cps) no increase in surface roughness could be noted. A theory has been developed for reversible electrodes ascribing this effect to the capacity of the pulsating potential to give an effective diffusion layer of constant thickness determined primarily by the frequency. At very high frequencies the diffusion layer is thin and follows the micro-profile of the surface so closely that the diffusion flux and the resulting deposit are even and no surface irregularity is amplified.

Notes: Abstract Times to passivation have been measured for zinc electrodes in KOH-KF solutions at room temperature. A linear relationship betweeni andt −1/2 was obtained. The intercept of these lines is interpreted to be a limiting current density. This limiting current density reaches a maximum in solutions 5M in KOH. Beyond this concentration the limiting current density decreases. This phenomenon is explained in terms of the loss of unbound water as the ionic strength of the solution increases.

Notes: Abstract The mercury/mercuric oxide electrode is examined for its applicability to high temperature alkaline solutions. It is found to be stable and reliable at temperatures up to 250°C in solutions of up to 5 M sodium hydroxide. It has been calibrated against the hydrogen electrode at temperatures up to 200°C. Loss of hydrogen from the autoclave prevented the calibration being extended to higher temperatures. Tests for the practicability of the electrode for use in high temperature polarization cells indicate that contamination of the solution in the working compartment results from slight dissolution of mercuric oxide. This contamination can be suppressed by isolating the reference electrode with a porous p.t.f.e. separator.

Notes: Abstract When designing and building new mercury-based chlorine plants special attention must be given to features which will help reduce mercury pollution of the environment. The article describes a new Swedish chlorine plant including mercury emission limits set by the authorities, general principles and some specific details in the plant design to minimize mercury losses and practical experience after nearly one year of operations.

Notes: Abstract A method is proposed whereby electrode impedance data may be analysed to yield information about the structure and composition of porous electrode materials. The method is more suitable for comparative investigations than as a technique for obtaining absolute values of the total surface area of a porous solid in contact with an electrolyte.

Notes: Abstract The feasibility of the electrochemical generation of Fenton's reagent is demonstrated and the subsequent reaction of produced OH radical with benzene studied. Under the proposed working conditions, phenol is obtained as the main product, with current yield as high as 60% (on the basis of 3 F/mole of phenol) and with only traces of other higher oxidized compounds. At fixed H2SO4 concentration and with suitable [Fe3+]/[O2] ratio, a maximum in current yield is obtained; this yield may presumably be increased if continuous removal of phenol is employed during the electrolysis.

Notes: Abstract Based on the optimum conditions arrived at in the laboratory experiments, large-scale trials have been carried out for the preparation of sodium perchlorate by the direct oxidation of sodium chloride in a single step using a graphite substrate lead dioxide anode. Two cells of 75 A capacity and one 400 A cell were run continuously at an anode current density of 20 A/dm2 and a temperature of 45°–50°C. The cell performance with these anodes is given. Potassium and ammonium perchlorates formed by double decomposing the sodium perchlorate obtained by this method with the respective chlorides are pure and conform to the stringent specifications.

Notes: Abstract The mechanism of formation of barrier-type anodic films on alloys containing valve and non-valve metals is considered in terms of data yielded by electrochemical methods, a.c. impedance measurements, conventional and scanning electron microscopy and chemical and electron probe microanalysis. The alloying elements enter the film virtually in their alloy proportions. With alloys giving oxides essentially insoluble in the electrolytes, such as Nb-Zr, the metal constituent concentration profiles across the film are determined largely by the cationic and anionic transport numbers and the cationic mobilities. Where one of the alloying elements tends to give soluble compounds, such as vanadium in V-Nb alloys, this situation is complicated by preferential dissolution of that element. The film properties depend on the solution used but the main result, that relatively small additions of valve metals to metals such as vanadium permit thick barrier-type films to be formed, is unaffected. All the as-formed films are initially pore-free, but those produced on alloys rich in non-valve metal are prone to subsequent leaching, with detectable pore formation. Analysis proves that the films on V-Nb alloys are enriched in valve metal, particularly towards the outer surface. This explains why these films can be formed and also why the impedance characteristics and resistance to leaching improve as the film thickens, with the material rich in valve metal developing into an outer, more protective and possibly thicker sheath. The presence of a mass-transfer boundary layer, rich in nonvalve metal dissolution products, also promotes film formation. Films formed in certain nonaqueous electrolytes are richer in the non-valve metal and so are more readily leached in water subsequently, but apparently are also chemically different. Special experiments, involving leaching and reanodizing in various solutions, and the formation of duplex films, provide important data, appearing to indicate substantial anionic movement during film growth.

Notes: Abstract A method which treats the fuel cell anode as a chemical reactor is developed to predict fuel cell performance. The method is based on experimentally measured residence time distribution parameters and differential cell kinetic data. The apparatus and experimental technique used to obtain the gas-phase residence time distributions are described. Kinetic data obtained from differential cell tests of the electrodes are used to evaluate an empirical rate expression. Axial dispersion model solutions for flow with volume change are obtained, based on the measured Peclet numbers and empirical rate expressions, and compared with experimental data from operating large high-temperature molten carbonate fuel cells. Agreement between the model and the experimentally determined data is very good, but only for low conversions of the fuel.

Notes: Abstract A new method of recovering chlorine from by-product hydrogen chloride is proposed and developed. According to the reaction Me+2HC1 = MeCl2+Ho (Me = Metal) hydrogen chloride is reduced to give hydrogen and metal chloride. Gaseous hydrogen was drawn out from the reaction system and the metal chloride dissolved in the electrolyte, where it was electrolysed to give chlorine and metal using molten metal as a cathode. The metal was recovered on the cathode in a molten state and reused for the former reaction. Bench scale tests were also carried out, where zinc was used as a molten metal cathode and the cell capacity was about 50 A. The cell voltage was 6.5 V at 50 A (working temperature 560°C, distance between anode and cathode 5 mm) and in this case, the ohmic loss was about 70%. The current efficiency was about 90% (anodic current density 200 A/dm2) when the working temperature was 500°C and electrode distance between anode and cathode was 18 mm. This method seems very promising on the basis of the above-mentioned data.

Notes: Abstract Molten carbonate fuel cells operate at 600–700°C. At these high temperatures, high surface area nickel anodes lose their activity rapidly due to sintering. A study of the sintering kinetics of Ni, Ni-Ag and Ag powder revealed that when Ni and Ag particles are present in similar numbers, sintering is significantly inhibited. This is achieved by minimizing volume diffusion between adjacent particles — Ni and Ag have virtually no solid solubility at any temperature. Paste electrolyte cells using such electrodes gave 114 mA/cm2 at 0.65 V on 80% H2/20% CO2 fuel, compared to 80 mA/cm2 at 0.65 V for a cell using sintered nickel anodes.

Notes: Abstract The corrosion of 18% Cr, 8% Ni steel has been studied in alkali metal sulphate eutectic melts as a function of the partial pressures of oxygen and SO3 in equilibrium with the melt at 873°K. The rate of corrosion has been measured in terms of the corrosion current corresponding to the balanced rates of the anodic and cathodic processes at the unpolarized metal surface. The effect of SO3 on the rate of corrosion is interpreted in terms of its role as an oxidizing agent and also in terms of its effect on the solubility of the corrosion products in the melt. The difference in the relative importance of oxygen and SO3 as the oxidizing agent is interpreted in terms of their different solubilities in the sulphate melt.

Notes: Abstract Anolytes adjacent to dissolving metal surfaces have been sampled after freezing using liquid nitrogen/ isopentane mixtures. Metal ion, anion and pH profiles were obtained after analysis of the samples. The results are discussed in terms of the solution flow rate and of the regimes obtaining at the time of freezing.

Notes: Abstract A study has been made of the passivating process at a zinc electrode in KOH solutions. Zinc electrodes were passivated at a constant overpotential and the current response during passivation was measured. The potential response after the passivating potential was removed was also measured. The current during passivation soon reached a semi-steady-state value which increased with increasing overpotential but varied only slightly with changing KOH concentrations. When electrodes were passivated at overpotentials 〉325 mV, the open circuit voltage decay showed an arrest, the duration of which decreased with increasing KOH concentration. This duration increased when ZnO was dissolved in the electrolyte, when the temperature was decreased, and when the passivating overpotential was increased. The results are interpreted by assuming that passivation is due to the formation of a film, possibly Zn(OH)2, which can dissolve in the electrolyte. The potential of the electrode is a mixed potential.

Notes: Abstract The preparation of lead chloride cathodes, and their discharge in magnesium-lead chloride batteries, is described. The lead chloride blended with graphite is pasted on grids of expanded copper, using urea formaldehyde solutions as the binder. One-, five-, and fifteen-cell batteries were discharged at temperatures between −40°C and +45°C, at low current drains. For five-cell batteries energy densities in the range 10–30 Wh/lb were obtained. Mechanical properties of the cathode, so far as investigated, were excellent. The main difficulty was cathode softening during prolonged runs at high temperatures. At −40°C the battery attained working voltage in about 5 minutes; although slower than the Mg-AgCl system, the Mg-PbCl2 system should meet many applications at this temperature.

Notes: Abstract Phosphate glasses are known to be mixtures of chain phosphates. The presence of the lower polymers has been confirmed by electrochemical techniques and the proportions of the orthophosphate monomer in sodium metaphosphate melts have been estimated at temperatures between 660–810°C. The orthophosphate had not been detected in phosphate glasses using paper chromatography, but it is considered that quenching tends to increase polymerization and thus causes loss of the monomer.

Notes: Abstract Galvanostatic polarization experiments, in which the current flow is interrupted and re-established, show that the process of passivation is controlled by the transport of mass in the solution phase.

Notes: Abstract Manganese dioxides which are suitable as cathodes for Leclanché cells need (a) a high MnO2 content and (b) battery activity. In this study it is shown that thermogravimetric analysis is a valuable method of screening manganese dioxides for battery activity. The parameter used is the temperature, under standard conditions, at which the rate of decomposition to Mn2O3 is maximum. This is called peak decomposition temperature. Battery activity, which was assessed from actual battery discharges, correlated well with peak decomposition temperature for the 20 manganese dioxides examined. A low peak decomposition temperature indicates high battery activity. As the total range of peak decomposition temperatures is only about 130°C, it is essential that the standard conditions are chosen to ensure decomposition of any one material over a narrow temperature range. For this reason the effects on sharpness of decomposition of gaseous environment, rate of gas flow, sample weight, particle size and rate of temperature rise have been examined. A significant improvement was effected by the use of an oxygen rather than a nitrogen environment.

Notes: Abstract The ‘Norbide’, boron carbide, electrode has been shown to be exceptionally good in terms of its chemical inertness, rapid response and high hydrogen overvoltage. It has been applied especially in potentiometric and polarographic studies of the Ir(IV)-Ir(III) system in various media. By its means, supported by evidence from use of other cathodes, certain previous work has been confirmed and standard or formal redox potentials of the following systems have been determined: Ir(IV)-Ir(III)-ClO 4 − (M HClO4, 1·27 V; Ir (IV)-Ir(III)-SO 4 2− (0·18M H2SO4), 1·08 V; Ir(IV)-Ir(III)-PO 4 3− (0·3M H3PO4), provisionally 0·99 V; IrCl 6 2− -IrCl 6 3− (0·1M NaClO4 or NaCl), 0·899 V; IrBr 6 2− -IrBr 6 2− (0·1M NaClO4or NaBr), 0·838 V. The potentials fall in the expected sequence. The possibility of analytical application of the ‘Norbide’ and rotating platinum electrode has also been examined.

Notes: Abstract The oxidation and reduction of a series of polycyclic aromatic hydrocarbons have been studied in molten tetrabutylammonium nitrate at 150°C. On the oxidation side nitrated products are formed and on the reduction side butyl-substituted products were obtained. In this solvent, which is slightly unstable at 150°C, limiting cathodic process is the reduction of the NBu4 + ion to tributylamine and butenes and the limiting anodic process is the oxidation of NBu4 + to carbon dioxide. Attempts to trap the reactive intermediates produced electrochemically with added substances were unsuccessful.

Notes: Abstract The electrical and structural properties of lithium compounds which present predominantly ionic conductivity are reviewed and relationships between structure and electrical properties are, where possible, discussed. A few results on lithium silico-aluminate glasses are also reported.

Notes: Zusammenfassung Das chromatographische Verhalten einiger Actinoide und Lanthanoide auf Dünnschichten aus Cellulose, Anionenaustauschern und Kationenaustauschern wird untersucht. Als Laufmittel wird eine Mischung von Isopropylalkohol, Wasser und HCl angewendet und die Abhängigkeit derR f-Werte von der Zusammensetzung dieser flüssigen Phase bestimmt. Aus den Ergebnissen kann geschlossen werden, daß die eingesetzten Ionen bei den gewählten Versuchsbedingungen in keinem Fall als anionische Komplexe vorliegen. Auf eine Trennmöglichkeit der eingesetzten Ionen wird hingewiesen.

Notes: Zusammenfassung 3-Amino-5-methylisoxazol wird mit Bernsteinsäureanhydrid in 3-Succinimido-5-methylisoxazol übergeführt, welches sich mit Oleum und rauch. HNO3 nitrieren läßt. Die Abnahme der Schutzgruppe zu 3-Amino-4-nitro-5-methylisoxazol erfolgt mit alkohol. HCl.

Notes: Zusammenfassung Die Festkörperelektronenspektren sowie die Infrarotspektren (im Bereich 4000−100 cm−1) der Verbindungen [Zn(NH3)4]-PtCl4 und [Cd(NH3)4]PtCl4 werden gemessen und kurz besprochen.

Notes: Zusammenfassung Das Verhalten von35S-markiertem Thioharnstoff bei der Elektrolyse in Kupfersulfatbädern wird mit Hilfe von Inkorporationsmessungen, dünnschichtchromatographischen Bestimmungen und Glanzmessungen untersucht. Die Inkorporationsmessungen zeigen, daß auf der Anode immer mehr Schwefelverbindungen eingebaut werden als auf der Kathode. Beim Versetzen des Elektrolyten mit Thioharnstoff bildet sich sofort der bekannte Kupfer—Thioharnstoff-Komplex. Durch dünnschichtchromatographische Untersuchungen wird festgestellt, daß dieser Komplex während der Elektrolyse zu Formamidinsulfin-und diese zu Formamidinsulfonsäure oxydiert wird. Aus Glanzmessungen ergibt sich, daß nur der Thioharnstoff als Glanzbildner wirkt. Die S-oxydierten Thioharnstoffabkömmlinge liefern nur matte Kupferabzüge.

Notes: Zusammenfassung Unter der Einwirkung von Polyphosphorsäure gehen Monoxime von Di- und Triketonen mit einem 7gliedrigen Ring (3 und8) in die Dibenzo[c, e]azocine4 bzw.9 über. Die Struktur der neuen Azocine wurde durch Elementar-, IR- und NMR-Analyse und einige chemische Umwandlungen bestätigt.

Notes: Zusammenfassung Die Ionisation vonPh 3CCl undPh 3CBr durch aprotische Donoren wurde in Nitrobenzol mit Hilfe von Leitfähigkeitsmessungen untersucht. Das Ausmaß der Ionisation ist proportional den Donizitäten. Ausnahmen werden auf sterische Hinderung zurückgeführt. Die Verbindung [Ph 3C·py]+Br− wurde isoliert.

Notes: Zusammenfassung In unpolaren Lösungsmitteln kondensieren sich monomeres und “dimeres” Malonitril mit Dimethylamino-phenyl-propenon zu linearen Dienen bzw. Trienen. 2-Cyan-5-dimethylamino-3-phenyl-2,4-pentadienamid (4) kann als Zwischenprodukt für die Bildung von Pyridonen aus Enaminoketonen und Cyanacetamid aufgefaßt werden, da in saurem Medium die Cyclisierung zum 2-Oxo-4-phenyl-1,2-dihydro-pyridin-3-carbonitril bzw. dem Carbonsäureamid gelingt.

Notes: Zusammenfassung 3,4,5-Trimethoxyanilin wird mit 2-Fluornitrobenzol zu 3,4,5-Trimethoxy-2′-nitrodiphenylamin umgesetzt, das sich mit NaNH2/3-Chlor-N,N-dimethylpropylamin am N alkylieren läßt. Katalytische Reduktion der Nitrogruppe gibt das entsprechende Amin, das diazotiert wird und in acetatgepufferter Lösung sich unter intramolekularer Kupplung zum Triazepin cyclisiert.

Notes: Zusammenfassung Oxazole lassen sich nach einem neuartigen Prinzip gewinnen, welches in der gleichzeitigen Umsetzung von Triphenylphosphin, einer α-Azidocarbonylverbindung N3CH(R1)COR2 und einem Säurehalogenid R3COX besteht.

Notes: Zusammenfassung 5-Carboxylsubstituierte 3,3-Diphenyl-2-amino-1-pyrroline werden vorteilhaft durch Cycloaddition von α-Acetaminoacrylester an Diphenylacetonitril hergestellt. Ein zweiter Syntheseweg, ausgehend von den 4,4-Diphenyl-4-cyan-2-brombuttersäurederivaten1 b oder1 d, verläuft wegen der HBr-Eliminierung während der Aminierung mit schlechten Ausbeuten. Es werden einige Amide der 3,3-Diphenyl-2-aminopyrrolin-5-carbonsäure (2 c), darunter das β-Carbamidinoäthylamid (rac. Diphenylnoformicin) (2 h) hergestellt. Die Reduktion des Äthylesters2 f führt zum 3,3-Diphenyl-2-amino-5-hydroxymethyl-1-pyrrolin (3).

Notes: Zusammenfassung Der Wasserstoffaustausch zwischen Äthan und Deuterium bzw. Tritium wird an Nickelpulver als Katalysator untersucht. Die auf Wasserstoff bezogene Reaktionsordnung nimmt im Temperaturgebeit 147–323°C zu, während die in bezug auf Äthan sich konträr verändert. Auch die Aktivierungsenergie nimmt ein wenig ab. Die Ergebnisse der Untersuchungen mittels Deuterium zeigen, daß die Hauptprodukte des Austausches Äthan-d2 und Äthan-d6 sind. Das Verhältnis der Anfangsgeschwindigkeiten der Bildung beider Produkte hängt von der Katalysatoraktivität und der Temperatur ab. Auf Grund des Vergleichs dieser Ergebnisse mit denen des Methanaustausches kann der große Unterschied im Verhalten beider Stoffe durch die Verschiedenheit der Adsorptionsmechanismen erklärt werden.

Notes: Zusammenfassung Die nichtenzymatische Reaktion von Schwefelwasserstoff (Indol),l-Serin und Pyridoxal führt zudl-Cystin (dl-Tryptophan). Dieser sterische Ablauf ist am einfachsten mit einem Reaktionsweg über Pyridoxyliden-aminoacrylsäure zu deuten. β-Eliminierungen anSchiffschen Basen von β-Hydroxy-β-Dialkylamino- und β-Äthylthio-alaninestern werden untersucht. In Gegenwart stark basischer Ionenaustauscher wird aus Salicyliden-S-äthhylcystein-äthylester (3) Äthylmercaptan eliminiert. An die gebildete Acrylsäure addiert sich ein weiteres Mol3 zu4.

Notes: Zusammenfassung Lithiumsalze der 1-Alkoxy-1-buten-3-ine lassen sich mit Säureanhydriden in guter Ausbeute zu 1-Alkoxy-1-alken-3-in-5-onen (1) acylieren, die durch alkalisch katalysierte Methanoladdition in Carbonylderivate von 3,5-Diketoaldehyden übergehen.

Notes: Zusammenfassung Das Verhalten einer nicht-isomorphen Beimengung bei der Entwässerung von Na2SO4·10H2O bis zum wasserfreien Salz in gesätt. Lösung bei der Temp. des Übergangs wurde untersucht. Es wurde festgestellt, daß der Entwässerungsprozeß von einem Prozeß der Beimengungsverminderung begleitet wird. Dabei wird bei der Re-Hydratisierung des Na2SO4 bis zu Na2SO4·10 H2O die Beimengung wieder eingeschlossen. Bei einem geringeren Gehalt an Beimengung in Na2SO4·10 H2O ist der Reinigungseffekt beim Entwässerungsprozeß kleiner und umgekehrt. In der Reihe Cl′, Br′, J′ wird — bei sonst gleichen Bedingungen — J′ am schwierigsten beseitigt, Cl′ am leichtesten. Außerdem ist die Abhängigkeit zwischen dem Reinigungseffekt (ausgedrückt durch den Reinigungskoeffizienten,W) und dem Ionenradius linear. Die Wasserstoffionenkonzentration in der gesättigten Na2SO4·10 H2O-Lösung übt keinen wesentlichen Einfluß auf die Beseitigung der Beimengung aus.

Notes: Zusammenfassung Für oxydative Abbauversuche wurden verschiedene spezifisch14C-kernmarkierte Phenolderivate benötigt. Guajacol, in verschiedenen Positionen des aromatischen Ringes markiert, wurde — teils von [1-14C]-Phenol, teils von [2-14C]-Aceton ausgehend — synthetisiert.

Notes: Zusammenfassung Es wird über die Darstellung der Titelverbindungen durch Addition von Phenylvinylketon an Lactame, durch Amin-Amid-Austausch sowie durch Umsetzung von β-Chlorpropiophenon mit Lactamen berichtet. Eine Synthese entsprechender tertiärer Hydroxylactame wird beschrieben.

Notes: Zusammenfassung Kristallstrukturelle Untersuchungen an Zinkchlorid-Triäthanolaminverbindungen haben innermolekulare Triäthanolaminkomplexe mit koordinativer Metall-Stickstoffbindung ergeben. Dieses Resultat kann bei bestimmten Verbindungen verallgemeinert werden.

Notes: Zusammenfassung Bei der Reaktion von Bariummetall mit elementarem Bor bildet sich in Gegenwart von Wasserstoff zunächst Bariumhydrid (BaH2). Im zweiten Reaktionsschritt diffundiert Bor in BaH2 ein, wobei die Umsetzung zu Bariumhexaborid (BaB6) durch die α-β-Umwandlung des BaH2 begünstigt wird. Im Gegensatz zu Lanthanhexaborid zeichnet sich BaB6 durch einen weiten Homogenitätsbereich aus.

Notes: Zusammenfassung AgNCO (I) geht bei 120° C in eine Hochtemperaturmodifikation über, oberhalb 335° C findet Zersetzung statt. Als gasförmige Zersetzungsprodukte wurden CO, N2, CO2, (CN)2 und NCNCO gefunden. DieTGA-Kurve weist wesentliche Unterschiede zu der in der Literatur angegebenen auf. Die Vakuumthermolyse von I wird als einfache Darstellungsmethode von NCNCO vorgeschlagen.

Notes: Zusammenfassung Am leicht zugänglichen Tris-(3-aminophenyl)-phosphinoxid (1) sind bisher nur wenige Reaktionen der Aminogruppen studiert worden. In direkter Umsetzung gelang uns die Formylierung zum Tris-(3-formamidophenyl)phosphinoxid und die Darstellung eines Sulfonamids, des Tris-(3-p-tosylamidophenyl)-phosphinoxids. Durch Diazotieren von1 gelangt man ferner zu Diazoniumsalzen, von deren weiteren Umwandlungsmöglichkeiten die Darstellung von Tris-(3-jodphenyl)-, Tris-(3-hydroxyphenyl)-und Tris-(3-acetoxyphenyl)phosphinoxid beschrieben wurden. Die Diazoniumsalze kuppeln zu Azofarbstoffen, die das Grundgerüst des Triphenylphosphinoxids enthalten. Als Kupplungskomponente für die Azofarbstoffe wurden α- und β-Naphthol, α-Naphthylamin, H-Säure und Naphthionsäure gewählt, um Vertreter der sauren, basischen und substantiven Farbstoffreihe zu studieren. Alle erhaltenen Farbstoffe sind in Substanz rot.

Notes: Zusammenfassung Amidoxim-äther lassen sich mit monosubstit. Malonsäurechloriden zu 6-Hydroxy-3,4-dihydro-4-pyrimidinonen (3 a−f) umsetzen. Malonylchlorid hingegen reagiert zu entsprechenden Pyrano-pyrimidinonen (5 a−d). Auch Kohlensuboxid kann als Cyclisierungskomponente eingesetzt werden (siehe3 g).

Notes: Zusammenfassung Optisch aktives Ferroceno[b]indenon (2) wurde durch kinetische Racematspaltung des gut zugänglichenendo-Ferroceno-indenols3 mit (+)-α-Phenylbuttersäure-anhydrid in optischen Ausbeuten um 20% erhalten. Aus den Ergebnissen dieser Racematspaltung (auch für dasexo-Carbinol5) ließen sich auf Grund der bekannten Absolutkonfiguration (+)-(1R)-2 die relativen stereochemischen Größen von Ferrocen und Benzol (Fc〉Phenyl) erstmals festlegen. Mehrere Folgeprodukte von (+)-2 (darunter Ferrocenohydrindene) wurden dargestellt und ihre chiroptischen Eigenschaften mit jenen von strukturell verwandten Ferrocenderivaten (wie13–18) verglichen (und diskutiert). DieCD-Kurven wurden einer Bandenanalyse unterworfen.

Notes: Zusammenfassung Das Verhalten verschiedener Komplexe von Metallen mit Dithiol-enen wird behandelt. Die photometrische Bestimmung, ein empfindlicher qualitativer Nachweis in drei Ausführungsformen und das Extraktionsverhalten von Antimon sowie eineDC-Trennung Sb−Sn−Bi−Pb mit Toluol-3,4-dithiol werden beschrieben. Versuche, die Struktur der Antimondithiolate aufzuklären, führen zu 2 Formeln. Die weitere analytische Verwendbarkeit dieser Verbindungsklasse wird diskutiert.

Notes: Zusammenfassung Es wird gezeigt, daß das Hydroxidion mit der α-Glucose auf zweierlei Weise reagiert. Einerseits bewirkt es durch Vermittlung der Hydrathülle Mutarotation der α-Glucose, andererseits reagiert es äußerst rasch als teilweise dehydratisiertes Hydroxidion unter Bildung des α-Glucosations, ohne Mutarotation der α-Glucose. Diese Erkenntnis in Verbindung mit der Bestimmung der Entropie der Wasserstoffbrückenbindung des hydratisierten Oxoniumions durch den Verfasser führt auch zu neuen Anschauungen über den Mechanismus sehr rascher Oxoniumion-reaktionen. Die Entropie der Wasserstoffbrückenbindung des hydratisierten Oxoniumions ΔS wurde vom Verfasser aus den Koeffizienten der Wasserkatalysek W und der Oxoniumionkatalysek H3O+ der Mutarotation der α-Glucose ermittelt: $$\Delta S = R ln {{k_w } \mathord{\left/ {\vphantom {{k_w } {k_{H_3 O^ + } }}} \right. \kern-\nulldelimiterspace} {k_{H_3 O^ + } }},$$ Da das Proton des hydratisierten Oxoniumions von den beiden Sauerstoffatomen gleich stark angezogen wird, ist (ΔS)/2 die Entropie der Wasserstoffbrückenbindung des einfach hydratisierten Protons, das sich als aktiviertes Oxoniumion der Reaktionen des Oxoniumions mit den Anionen erweist. Während für die Reaktion des Oxoniumions mit dem Hydroxidion nur die Aktivierung des Oxoniumions erforderlich ist, muß bei der Reaktion mit Acetation außerdem dieses Anion aktiviert werden (Trennung der inneren Wasserstoffbrückenbindung). Die Aktivierungsenthalpie des Acetations wird aus der Acetation-und Wasserkatalyse der Mutarotation der α-Glucose ermittelt. Die Aktivierungsenthalpie der Reaktion des Oxoniumions mit Acetation ist also die Summe der Aktivierungsenthalpien des Oxoniumions und des Anions. Die hohe Wanderungsgeschwindigkeit des Wasserstoffions in wäßriger Lösung ist auf den durch das einfach hydratisierte Proton initiierten Protonenaustausch zwischen den Wassermolekülen zurückzuführen.

Notes: Zusammenfassung Es wird gezeigt, daß mit einem starken Reduktionsmittel eineLewis-Säure bzw. mit einem starken Oxidationsmittel eineLewis-Base korrespondiert; dies erlaubt, das Prinzip der chemischen Funktionsfolge zu formulieren: Wird nach Ausübung einer Funktion die Kompensation der hiedurch veränderten Elektronenpopulation angestrebt, so erfolgt Funktionsumkehr, so daß eine Funktion induziert wird, die der unmittelbar vorher ausgeübten nicht korreliert ist. Die Anwendung des Prinzips führt zur zwanglosen Beschreibung der Stabilisierung verschiedener Oxidationsstufen, der Dynamik der koordinationsbedingten Ionisation und der Dynamik der Errichtung chemischer Bindungen.

Notes: Zusammenfassung Bei der Einwirkung von Äthylenimin und Schwefel auf Methyläthylketon, Methylisopropylketon und Äthylisopropylketon entstehen strukturisomere 5,6-Dihydro-1,4-thiazine (1–6) und als Nebenprodukte die dem jeweiligen Keton entsprechenden Thiazolidine (7–9). Die 5,6-Dihydro-1,4-thiazine werden mit Ameisensäure in N-Formylthiomorpholine (10–15) übergeführt, die mit verd. HCl glatt zu den entsprechenden Thiomorpholinen (16–21) hydrolysiert werden. Das Verhältnis der Thiomorpholin-Isomerenpaare wird gaschromatographisch quantitativ bestimmt.

Notes: Abstract Reaction of 14-bromo-codeinone dimethyl acetal (1) with methanol in presence of Na2CO3 yields 7-methoxy-neopinonedimethyl acetal (2 b) and 14-methoxy-codeinone dimethyl acetal (6 b). The structures of the new compounds are proved.

Notes: Abstract The synthesis of (7R)-7-Hydroxy-neopinone dimethyl acetal (6) has been performed by shaking on air a solution of 14-bromo-codeinone-dimethyl acetal (1 b) in alcoholic NaOH in the presence of an especially prepared hydrogenation catalyst in 75% yield. The by-products7, 8, 9, 10a, and10b were isolated by preparative thin layer chromatography. The structures and the configuration on C-7 were established on the basis of NMR-spectroscopy.

Notes: Abstract The complex formation between La(III) and 3.5-dinitrosalicylic acid in 0.1m-KNO3 medium has been studied potentiometrically and conductometrically. The formation of 1∶1 and 1∶2 complexes beyond 3.5 pH was investigated. 1∶1 complex is formed in solution while 1∶2 complex is precipitated. The stability constant of the 1∶1 complex was determined by applying the Calvin and Melchior's extension ofBjerrum's method. The logK values have been found to be 4.92, 5.00, and 5.12 at 25, 30 and 35°C, respectively. The values of ΔF, ΔH, and ΔS have also been evaluated at 30°C and found to be−6.97 Kcal/mole,−7.49 Kcal/mole, and−1.70 Kcal/mole/degree, respectively.