Fluorine-containing azoles. 2. Reaction of imidazole,benzimidazoles, and perimidines with difluorocarbene

The reaction of difluorocarbene, generated from difluorochloromethane in an alkaline medium or from sodium trifluoroacetate in a neutral medium, with imidazole, tetrahydrobenzimidazole, benzimidazoles, and perimidines leads to the production of their N-difluoromethyl-substituted derivatives.See [1] for communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 520–523, April, 1984.     

Analytical applications of picolinealdehyde salicyloylhydrazone: Spectrophotometric determination of nickel and zinc

With a view to the use of picolinealdehyde salicyloylhydrazone as analytical reagent, a study of the physical properties and chemical reactions of this substance has been carried out. It reacts with nickel (λ_max = 375 nm, ? = 3.9 × 10⁴M^?1cm^?1) or zinc (λ_max = 365 nm, ? = 4.8 × 10⁴M^?1cm^?1) to produce a yellow 1:2 complex in both cases. Spectrophotometric determinations of trace amounts of nickel and zinc have been established.     

Itinerant electron ferromagnetism in Sr2+-, Ca2+-, and Ba2+-doped rare-earth orthocobaltites (Ln3+1−xM2+xCoO3)

Electronic and magnetic properties of Ln_1?xSr_xCoO₃ (Ln = Pr, Nd, Sm, Eu, and Gd) systems show that above a critical value of x, the d electrons become itinerant while the materials become ferromagnetic at low temperatures. The ferromagnetic component increases with increase in x and decrease in temperature. The Curie temperature increases with x and decreases with decrease in the size of the rare-earth ion. Incorporation of Ba²⁺ in LaCoO₃ favors itinerant electron ferromagnetism relative to Sr²⁺ while Ca²⁺ is less favorable than Sr²⁺.     

Polystyrene resins with immobilized polyamines: Preparation,characterization, and ability to bind Cu(II) ions

Three polyamine ligands, ethylenediamine (EDA), diethylenetriamine (DTA), and triethylenetetramine (TETA), were bound to three chloromethylated “popcorn” polystyrene resins (16, 50, and 100% phenyl ring substitution) with the use of pyridine as the reaction medium. The rate of chloride displacement decreased with increasing molecular weight of the amine and higher degree of resin chloromethylation, while the extent of multiple attachments to the polymer matrix increased. The additional crosslinking, a result of multiple attachments, caused the polyamine resins to swell to a lesser extent in pyridine and water. The ability of the insoluble polyamine–polystyrene resins to chelate Cu²⁺ ions from dilute solutions (200 ppm) was determined at pH 5. With EDA resins the capacity for Cu²⁺ increased with increasing amount of the bound polyamine, with DTA it remained unchanged, while with TETA it was found to decrease.     

Zur Entwicklung der Oberflächenrauhigkeit während des Sputterns

Zusammenfassung Die zeitliche Entwicklung der Mikrorauhigkeit einer Oberfläche während des Sputterns wurde für verschiedene Größen der Oberflächendiffusionskoeffizienten untersucht. Das Modell berücksichtigt die Bedeckungsgradabhängigkeit der Diffusionsweglänge. Effekte der Korrelation zwischen Atomen beim Sputtern wurden diskutiert. Es wurde gezeigt, daß ab einem Schwellenwert des Oberflächendiffusionskoeffizienten die Tiefenauflösung nahezu konstant wird, statt mit der Quadratwurzel der Sputtertiefen anzuwachsen.

---

The development of surface roughness during sputtering

Summary The time-dependence of the micro roughness of a surface during sputtering is investigated for various values of the coefficient of surface diffusionD _s using a model of a coverage dependent diffusion length. Effects of correlation between atoms within the sputtered layer are discussed. It is shown that beginning at a threshold value ofD _s the depth resolution of sputtering becomes a constant instead of being proportional to the square root of the sputter depth.

---

---

Vorgetragen beim 10. Kolloquium über metallkundliche Analyse, Wien, 3.-5. November 1980. -Herrn Prof. Dr. Hanns Malissa zum 60. Geburtstag gewidmet.     

Photoinduced activation of molecular oxygen by various porphyrins,bis-porphyrins,phthalocyanines, pyridinoporphyrazins,and their metal derivatives

Aerobic irradiation of tetraphenylporphyrins, phthalocyanines, tetra-t-butylphthalocyanines, tetracarboxylphthalocyanines, tetrapyridinoporphyrazins and some of their metal derivatives with visible light (λ > 420 nm) give singlet oxygen by energy transfer and oxygen superoxide by electron transfer, but some of their Cu, Zn of Pt derivatives are efficient quenchers for superoxide formation.     

HOST CELL REACTIVATION BY FIBROBLASTS FROM PATIENTS WITH PIGMENTARY DEGENERATION OF THE RETINA

–Cockayne syndrome (CS) is an autosomal recessive disease characterized by numerous clinical abnormalities including acute sun sensitivity and primary pigmentary degeneration of the retina. Cultured fibroblasts from CS patients are hypersensitive to ultraviolet (UV) radiation. Since host cell reactivation of irradiated virus is a useful probe to evaluate repair in different host cells, we studied such host cell reactivation in CS and in other diseases with retinal degeneration. The survival of UV-irradiated Herpes simplex virus type 1 was determined in fibroblast lines from four normal donors. two patients with CS, one with both xeroderma pigmentosum (XP) and CS, and from several other patients with (Usher syndrome, olivopontocerebellar atrophy, retinitis pigmentosa) and without (XP, ataxia telangiectasia) primary pigmentary degeneration of the retina. The viral survival curves (log survival vs linear fluence) in all cell lines showed two components: a very sensitive initial component (not quantitated in this study) followed by an exponential, less sensitive component. The exponential component had greater sensitivity than normal in the case of the CS patients, the patient with both XP and CS. and the XP patient. We propose that patients with CS have defective repair of DNA which may be the cause of their retinal degeneration.     

Darstellung,thermisches Verhalten und Kristallstruktur des Calciumarsenidchlorids Ca3AsCl3

Preparation, Thermal Stability, and Crystal Structure of the Calcium Arsenide Chloride Ca₃AsCl₃ CaAsCa₃AsCl₃ was prepared as a grayish white, microcrystalline powder by the reaction of Ca, As, and CaCl₂ in the molar ratio 3:2:3 and by the reaction of “Ca₃As₂” and CaCl₂ in the molar ratio 1:3. Colourless single crystals of the compound were obtained. Ca₃AsCl₃ begins to decompose reversibly at 1 025°C by forming the phase Ca_{2? x}As_{1? x}Cl_1+x with x = 0.1₃ and CaCl₂. Single crystal investigations show that Ca₃AsCl₃ is isotypic with Mg₃NF₃; see: “Inhaltsübersicht”.     

Role of rhenium in bimetallic reforming catalysts

The influence of rhenium on the behavior of a Pt/Al₂O₃ catalyst was studied in n-hexane reaction by means of dilution of the catalyst bed with Re/Al₂O₃. Parallel to activity, selectivity and ageing data obtained in slug pulse and continuous flow reactors, the amount of the surface carbon formed during the reaction was determined and its reactivity in hydrogen atmosphere was also studied. It is suggested that in the presence of rhenium due to the increase in the amount of hydrogen available for hydrogen consuming reactions including hydrodepolymerization of the carbonaceous surface overlayer, the routes of ageing processes are changed, resulting in lower carbon content on the catalyst and less pronounced catalyst deactivation.

---

Pt/Al₂O₃ -, Re/Al₂O₃. , , , , . , , , , , , , .