Strukturuntersuchungen an PF/cellulosepapier-verbunden mittels dynamisch-mechanischer analyse

This paper tries to connect the structure of tung oil and tricresyl phosphate modified phenolic paper-base laminates used for printed circuit boards in a large scale, with properties of these laminates by means of dynamic-mechanical analysis and dielectric measurements. The internal plasticization of tung oil is discussed. The modification of phenolic resin with tung oil causes in addition to flexibilisation, that a higher conversion of functional groups during the resit formation is attained by removal of steric hindrances, in this way the degree of cross-linkage is increased in comparison to the unmodified laminate. The measurements show that tricresyl phosphate is an external plasticizer which reduces the intermolecular interactions.     

Photochemie von Aminoketonen. V. Diastereoselektive Synthese von 3-Aryl-azetidin-3-olen durch Photocyclisierung von Aryl-α-amidoalkyl-ketonen

Photochemistry of Aminoketones. V. Diastereoselective Synthesis of 3-Aryl-azetidin-3-ols via Photocyclization of Aryl-α-amidoalkyl-ketones N-Acyl-azetidin-3-ols 3 and 4 are formed by diastereoselective cyclization of n,π*-excited N-benzyl-N-phenacyl-amides 1 and 2 in ether solution. Dependent on the nature of the p-and α-substituents of the phenacyl part and especially of the N-acylgroups in the amides 1 and 2 competing reactions occur, particularly the NORRISH II cleavage and an oxydative cleavage of the intermediate hydroxybiradicals A . N-Acylgroups with low energy barrier ΔG^≠ of internal rotation favour the diastereoselective photocyclization by intramolecular interaction between the amide oxygen atom and the n,π*-CO-group in 1 *, 2 * and the OH group in the biradicals A , respectively. An intramolecular hydrogen bonding enables the N-tosyl-azetidinols 3 to rearrange to the N-tosylamino-methyl-benzhydryl-ketones 6 by 1 -sensitized photoreaction.     

Azomethinimine. I. Zur Photoreversibilität des Systems Azomethinimin/Diaziridin,untersucht an Pyrazolidon-Azomethiniminen

Azomethine-Imines. I. To the Photoreversibility of the System Azomethine-Imine/Diaziridine,Investigated on Pyrazolidone-Azomethine-Imines Pyrazolidone-azomethine-Imines of the type 1 with polycyclic aromatic substituents R undergo a photoreversible reaction to diaziridines 2 . In the u.v./VIS-spectra of the two forms 1 and 2 the difference of the λ_max-values is about 100 nm. Therefore this system is suitable as a new reversible photochromic system. The influence of substituents R′ to the u.v./VIS-spectra of the 1.3-dipolar form 1 is discussed.     

Reverse ATRP of acrylonitrile with diethyl 2,3-dicyano-2,3-diphenyl succinate/FeCl3/iminodiacetic acid

The reverse atom transfer radical polymerization (RATRP) technique using FeCl₃/iminodiacetic acid (IMA) complex as a catalyst was applied to the living radical polymerization of acrylonitrile (AN). A hexa-substituted ethane thermal initiator, diethyl 2,3-dicyano-2,3-diphenylsuccinate (DCDPS), was firstly used as the initiator in this iron-based RATRP system. The polymerization in N,N-dimethylformamide not only shows the best control of molecular weight and its distribution but also provides rather rapid reaction rate with the ratio of [AN]:[DCDPS]:[FeCl₃]:[IMA] at 500:1:2:4. The rate of polymerization increases with increasing the polymerization temperature and the apparent activation energy was calculated to be 49.9 kJ mol⁻¹. The polymers obtained were end-functionalized by chlorine atom, and they were used as macroinitiators to proceed the chain extension polymerization in the presence of FeCl₂/IMA catalyst system via a conventional ATRP process. The resultant polyacrylonitrile fibers were obtained with the fineness at 1.16 dtex and the tenacity at 6.01cN dtex⁻¹.     

Dyes for synthetic-polymer fibres: I72 I72 V 2 14H-naphtho[2,3-a]phenothiazine-8,13-diones I72 I72 V 3 and 1H-2,3-dihydroanthra[2,1-b][1,4]-thiazine-7,12-diones I72 I72 V 3

Condensation of 1-amino- or 1-hydroxy-2-bromoanthraquinones with 2-amino-benzenethiol, I72 I72 V 2 or of 1-amino-2-bromoanthraquinones with 2-nitrobenzenethiol I72 I72 V 3 gives 14H-naphtho[2,3-a]-phenothiazine-8,13-diones. The related 1H-2,3- I72 I72 V 3 dihydroanthra[2,1-b][1,4]thiazine-7,12-diones result from interaction of 1- I72 I72 V 3 amino-2-mercaptoanthraquinones with 1,2-dibromoethane or of 1-hydroxy-2- I72 I72 V 3 bromoanthraquinones with 2-aminoethanethiol. The colour, dyeing and fastness I72 I72 V 3 properties of these compounds on synthetic-polymer fibres are described. I72 I72 V 3     

Dyes for synthetic-polymer fibres: 14H-naphtho[2,3-a]phenothiazine-8,13-diones I72 I72 V 3 and 1H-2,3-dihydroanthra[2,1-b][1,4]-thiazine-7,12-diones I72 I72 V 3

Condensation of 1-amino- or 1-hydroxy-2-bromoanthraquinones with 2-amino-benzenethiol, or of 1-amino-2-bromoanthraquinones with 2-nitrobenzenethiol I72 I72 V 3 gives 14H-naphtho[2,3-a]-phenothiazine-8,13-diones. The related 1H-2,3- I72 I72 V 3 dihydroanthra[2,1-b][1,4]thiazine-7,12-diones result from interaction of 1- I72 I72 V 3 amino-2-mercaptoanthraquinones with 1,2-dibromoethane or of 1-hydroxy-2- I72 I72 V 3 bromoanthraquinones with 2-aminoethanethiol. The colour, dyeing and fastness I72 I72 V 3 properties of these compounds on synthetic-polymer fibres are described. I72 I72 V 3     

Oxidation of aroylthioureas during their reactions with 2,3-diphenylcyclopropenone resulting in (E/Z)-3-(aroylthioureido)-2-phenylcinnamic acids

Isolated (E/Z)-3-(aroylthioureido)-2-phenylcinnamic acids have been obtained from the reactions of N-substituted-aroylthioureas with 2,3-diphenylcyclopropenone in acetic acid. The abnormal behavior of the reaction was described as due to nucleophilic addition of N ³ followed by hydrolysis, ring opening and oxidation processes.     

Azomethinimine. VI. Zum thermischen Verhalten des Photochromiesystems Azomethinimin/Diaziridin,untersucht an Pyrazolidon-(3)-azomethiniminen und deren Photoprodukten

Azomethineimine. VI. On the Thermic Behaviour of the Photochromic System Azomethineimine/Diaziridine, Investigated by Means of the Photoproducts of Pyrazolidone-(3)-Azomethineimines The photochemically obtained cycloproducts 2 of pyrazolidone-(3)-azomethineimines 1 react thermically to 1 in aprotic solvents. This backreaction was investigated by following up the growth of the intensive long wave absorptionband of 1 . The kinetic analysis was carried out according to SWINBOURNE [5, 6]. The thermic backreaction is accelerated by factors favouring a polarization of the C N(2)-bond (C^δ+  N^δ−) of diaziridine 2 . Such factors are polar solvents, donors in the substituent R and extensive, easily polarizable π-electronic systems in R. The influence of substituents on the backreaction can be correlated by means of the σ⁺-Hammett-constants. For most compounds the values of E_A ≈ ΔH^≠, Δ^≠ and ΔG^≠ were determined. The possible reaction mechanism is discussed. The influence of steric factors on the thermic backreaction is regarded as a first indication of an exo-form of the bicyclic diaziridines 2 .     

A reversible oxygen electrode in an equimolar KNO3-NaNO3 melt saturated with sodium peroxide—I. An equilibrium study

A reversible graphite oxygen electrode has been found in molten (K-Na)NO₃ eutectic, saturated with sodium peroxide. The measured emf of ?1150 ± 5 mV at 503 K vs Ag|Ag⁺ (0.1 m) and its temperature dependence ?0.44 mV K^?1 are compared with theoretical values, obtained with thermodynamic data.An independent value of the superoxide disproportionation constant K_p = (5.3 ± 0.3) × 10^?2 kg atm mol^?1 at 503 K has been obtained. Our equilibrium experiments confirm the results of Zambonin et al.     

3C-NMR-Untersuchungen an Steroiden,III. Sterische Effekte von 2,3-substituierten Cholestanderivaten und deren Anwendung zur Konfigurationsbestimmung

¹³C-N.M.R-Investigations of Steroids. III. Steric Effects of 2,3 Substituted Cholestane Derivatives and their Application for the Configurational Analysis The steric effects on ¹³C chemical shifts and their use for the determination of the substituent configuration of 5α and 5β-cholestane (cholestane and coprostane), their 3-OH derivatives and some 2-mono- and 2,3-disubstituted cholestanes are investigated. Because the substituent effect of the C₈H₁₇ group at C-17 of cholestane and coprostane is very small for the carbon atoms of the rings A and B of the steroid skeleton, the discussed results are useful also for androstane derivatives with and without substitutions at the ring D.     

Zur dynamik des katalytischen festbettreaktors bei katalysator-desaktivierung—I.

The influence of catalyst deactivation on the dynamic behaviour of a catalytic fixed-bed-reactor is investigated. Using the spatially one-dimensional two-phase-model and an additional differential equation for the activity, profiles of temperature and activity are shown and compared to experimental results. It turns out that, due to deactivation, moving reaction zones can occur even at constant inlet conditions and that, in case of rapid deactivation, serious overheating of the reactor may result.     

Oberflächenaktive Anlagerungsprodukte des Glycids I. Nonylphenolpolyglycerinether

Surface Active Products of Glycide: I. Nonylphenolpolyglyceroether The reaction of glycidol (2,3-expoxypropan-l-ol) with nonlylphenol yields surface active products with excellent stability to concentrated aqueous salt solutions even at high temperatures. The properties of this class of compounds is described in comparison to ethoxylated products.     

NMR-Untersuchungen an Dicyclopentadien-Derivaten. VII. Zur Abhängigkeit des γ-gauche Effektes von der sterischen Kompression eng benachbarter Protonen bei exo/endo-Isomerieumkehr

N.M.R. Investigations of Dicyclopentadiene Derivatives. VII. Dependence of the γ-Gauche Effect on the Steric Compression of Closely Neighbouring Protons during the Reversal of Exo/Endo-Isomerism The ¹³C-chemical shifts of the carbon atoms C¹, C⁶, C⁷, C⁸ and C¹⁰ of different substituted exo/endo-isomeric dicyclopentadiene derivatives are highly depending on the configuration of these compounds. The observed shift effects are discussed within the concept of the steric γ-gauche effect and are not only explained by nonbonding interactions of steric closely neighbouring protons.     

MO-Berechnungen an Heterocyclen. XXV. Zur Elektronenstruktur des Pyridin-N-Oxids

MO-Calculations on Heterocycles. XXV. On the Electronic Structure of Pyridin-N-Oxide MO calculations with different levels of sophistication (ab initio, HAM/3, INDO-, CNDO- and PPP-typ) are reported. The eigenvalues of the different methods are correlated with the experimentally known assignment of the PE spectrum on the basis of HeI/HeII intensities. The pattern of the PE spectrum and also the large dipole moment make this compound a very useful test molecule for quantumchemical calculations. Comments are made concerning the calculation of dipole moments within the point charge model especially in the PPP-approximation.     

Etude des systemes Na3AIF6Ta2O5 et Na3AIF6NaTaO3—I. Leur comportement chimique et leur diagramme d'equilibre

The behaviour of the Na₃AIF₆Ta₂O₅ system, as studied by means of thermal analysis, has been shown to be more complex than the simple binary system. The latter is due to the reaction

forming the sodium tantalate. The equilibrium diagram of the Na₃AIF₆NaTaO₃ system, which behaves as real binary system, was determined by different thermal analysis techniques and microprobe analysis.     

AgNO3-TLC/HPLC-Untersuchungen zur Struktur des chinesischen Talgbaumfettes

Investigations on the Structure of Chinese Tallow using AgNO₃-TLC and HPLC Chinese tallow is a vegetable fat with interesting properties, containing almost exclusively palmitic and oleic acid. With more than 80% of the total triacylglycerols, POP (symmetrical dipalmitoyl oleoyl glycerol) is the main component of chinese tallow. In this investigation, methodical details of an improved combination of silver nitrate complexation TLC and HPLC and their application to an analysis of the triglyceride composition of chinese tallow are described. Own results on fatty acid and triacylglycerol composition of chinese tallow are compared with data from the literature.