Lichtabsorption und Substituenteneffekte bei Stilben-4-diazoniumionen

Light Absorption and Substituent Effects of Stibene-4-diazonium Ions Substituent effects on ṽ_max-values of 31 stilbene-4-diazonium ions are studied. With increasing donor strength of a substituent in 4′-position the long wave absorption band of stibene-4-diazonium ions shifts from the ultraviolet to the red region of the spectrum. The particular deep colour of diazonium compounds may be described by the very high σ_p-Hammett-constant of the diazonium group. The substituent effects found characterize stilbene diazonium ions as typical donor-acceptor chromogenes.     

Zur Regio- und Stereoselektivität nucleophiler Thioladditionen an Polyine

On the Regio- and Stereoselectivity of Nucleophilic Thiol Additions to Polyines Nucleophilic thiophenol additions to α,ω-diphenyl polyines Ph-(CC)_n-Ph (n = 2–4) (1–3) take a regio- and stereoselective course. The well-defined, crystalline addition products bind the phenylthio group in terminal position of the aliphatic chain, the resulting C, C-double bonds of the mono- (4, 6, 8) and bis-addition products (5, 7, 9) are (Z)-configurated, as unequivocally proved by ¹³C-n.m.r. analysis.     

Zur unterschiedlichen Wirksamkeit sauer und alkalisch eingestellter Tenside an der menschlichen Haut

Difference in the Action of Surfactants Adjusted to Acidic and Alkaline Conditions on Human Skin Sequel to previous investigations, the results of the examination of synthetic washing agents, which exhibit optimum washing action at pH 6–8, are reported. It was found that the side-effects, such as those involved in the alkali neutralisation test, are directly proportional to pH-value. The side-effects which are associated with the determination of wetting and water removal of skin are directly proportional to values between pH 6 and 8, depending on whether alkali soaps or surfactants of the type Na-laurylsulfate are employed. Unexpectedly, the roughness of the skin increased with increased alkalinity of the solutions. As observed in one particular case, the adjustment of a surfactant to a definite pH-value may result in totally unexpected changes in its action.     

MO-LCAO-Berechnungen an Polymethinen. IX. Zur Farbigkeit gekoppelter Oxonol- und Cyaninfarbstoffe

MO-LCAO Calculations on Polymethines. IX. On the Chromaticity of Coupled Oxonol and Cyanine Dyes Streptopolymethines display low-energy electronic transitions with a high transition probability and possess, moreover, a high capability to accept or to release electrons. These properties account for the absorption colour of polymethine dyes consisting of two molecular fragments. Scope and limitations of a composite-molecule approach can be recognized by subjecting the electronic wavefunctions to the so-called configuration analysis. Colour-structure relationships are derived from inspection of key orbital interactions between the molecular fragments.     

Zur Kombination von Desinfektionsmitteln und Waschmitteln Anforderungen an die Wäschedesinfektion

Combination of Disinfectants and Washing Agents: Requirements for the Disinfection of Laundry The general use of disinfectants in common washing processes is not recommendable, since the complete effectiveness of a disinfectant is achieved only if it is used under controlled conditions. The Swiss Microbiological Society has recommended specifications on the requirements which should be fulfilled in various processes of disinfection. On this basis, the various requirements in the disinfection of laundry are explained. They include the elimination of undesirable germs, non-injurious action on material and surroundings, non-toxic nature, compatibility with other accompanying substances, flexibility in application, desirable chemical and physical properties, as well as usual periods of action.     

Zur Untersuchung und Beurteilung fritierter Lebensmittel

Investigation and Assay of Fried Food A simple method for the detection of heated fats in fatcontaining foods is reported. The results obtained by this method on foods baked in fat and on fried fish are given. Based on the experience gained so far the limiting values for a possible assay are discussed.     

Zur Fleischartbestimmung aus Fettbestandteilen und Fettbegleitstoffen

Determination of the Nature of Meat from the Fat-Components and Substances Accompanying Fats Foodstuffs in a ready-to-serve state are more and more preferred by the consumer. In order to prevent adulteration as far as possible, investigations within the scope of general control must include the examination of the nature of meat as well. Taking the examples of beef, pork and meats of horse, cangaroo, hare, tiger and elefant, it is shown, that on the basis of polyunsaturated fatty acids (linoleic, linolenic, and arachidonic) along with cholesterol of the meat fat, a reasonably good assessment of the nature of the meat can be performed.     

Zur Probenvorbereitung und Homogenisierung pulverförmiger Wasch- und Reinigungsmittel

Sample Preparation and Homogenization of Solid Detergents. Solid detergents can be homogenized better than in other way by grinding in the ?Ultra-Zentrifugalmühle”?®. The better reproducibility after grinding is demonstrated with a cleaner for automatic dish washer and with a perborate containing detergent.     

Zur Adsorption von Dämpfen chlorierter C2-Kohlenwasserstoffe an Adsorberpolymeren und Aktivkohlen

Adsorption of Vapors of Chlorinated C₂-Hydrocarbons on Polymeric Adsorbents and Activated Carbons The adsorption (isotherms, kinetics, dynamics) of vapors of chlorinated ethanes and ethylenes from inert gas onto the novel crosslinked polymeric adsorbent Wofatit Y 77 was studied in comparison to traditional polymeric adsorbent Wofatit EP 61 and activated carbons B 23 and R 23 at 20°C. The crosslinked microporous polymeric adsorbent Wofatit Y 77 adsorbs the greatest amount. But the adsorption velocity is slightly lower than at activated carbons and the macroporous polymeric adsorbent Wofatit EP 61, respectively. The obtained steep adsorption breakthrough curves were evaluated according to the model of adsorption zone. Furthermore, the breakthrough curves were predicted from data of equilibrium and kinetics due to the equilibrium model and the model of film and pore diffusion by Rosen.