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.     

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”.     

Modification chimique des polyalcadiènes par les composés du type CX3Z—I Addition catalysée des composés CCl3Z sur les polybutadiènes-1,2

The influence of catalysis on chemical modification of 1,2-polybutadienes (M_n < 10,000) by CX₃Z reagents (X = halogen; Z = functional group or halogen), in order to obtain polymers soluble in common solvents, has been studied. The work has been carried out with carbon tetrachloride, trichloromethylphosphonyldichloride (CCl₃POCl₂) and ethyl trichloroacetate (CCl₃CO₂Et) in the presence of solvents such as C₆H₆, CH₂Cl₂. Among the compounds tested as catalysts for the addition of CX₃Z to 1,2-polybutadiene (transition metal salts and complexes; radical initiators) only the systems formed with metal salts such as CuCl₂, FeCl₃, RuCl₃ 3H₂O, Fe₂(CO)₉ and Cl₂Ru(PPh₃)₃ were found to show high catalytic activity. The most active is Cl₂Ru(PPh₃)₃: used without or with cocatalysts (Et₃NHCl/benzôin, alcohols), it leads always, to the best yields whatever the nature of CX₃Z. The activity of the other catalysts is generally dependent on CX₃Z structure. Some secondary reactions (cross-linking, cyclization, transesterification) have been found.     

Use of reference pools to compare the qualitative and quantitative determination of polychlorinated biphenyls by packed and capillary gas chromatography with electron capture detection. Part 1. Serum

Serum for reference pools of in vivo polychlorinated biphenyls (PCBs) was obtained from four goats that had received one dose (100 mg kg-1) of a selected technical Aroclor (AR) (1016, 1242, 1254 or 1260) and were allowed to recover for 30 d. These pools were used to assess the differences in an analytical method that determines and quantifies PCBs using packed-column gas chromatography (PCGC) (quantified on the basis of mean mass percent. data for grouped PCB peaks) and capillary-column gas chromatography (CCGC) (quantified on the basis of percent. composition data for specific congeners). With CCGC, results were statistically significantly different (p less than or equal to 0.0002) from results with PCGC for ARs 1016, 1242 and 1254 but not for AR 1260 (p = 0.23). When comparing these gas chromatographic methods using bovine serum spiked in vitro with the same ARs at 17-25 p.p.b., it was found that the methods were not statistically significantly different for any of the ARs (p = 0.30-0.92). Levels of serum PCB determined by the two methods for 12 persons, divided into two groups according to exposure, were compared using the paired t-test. Group 1 consisted of three persons with dietary and/or environmental exposure; one with dietary and/or environmental exposure in addition to occupational exposure dating back 20 years. Group 2 consisted of eight persons with recent occupational exposure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Extractive spectrophotometric determination of uranium with Malachite Green

A sensitive spectrophotometric method based on the extraction of a uranium-benzoate-Malachite Green complex by chlorobenzene is described. The absorption maximum is at 635 nm and the molar absorptivity is 8.3 x 10(4) 1 mole(-1), cm(-1). A preliminary separation of uranium by extraction with methyl isobutyl ketone from acid-deficient aluminium nitrate solution is used to avoid interferences. An aliquot of the extract is then diluted with chlorobenzene and shaken with benzoate buffer containing Malachite Green (MG). The method has been applied for the determination of uranium in a synthetic leach solution. The complex extracted is probably [MG(2)(C(6)H(5)COO)(3)][MG(+)].     

The molecular structure of tetrathiofulvalene-13C (TTF) from proton magnetic resonance studies using nematic solvents

The molecular structure of TTF dissolved in nematic liquid crystalline solvents has been determined from the proton magnetic resonance including couplings due to ¹³C in natural abundance. The molecule is puckered in a boat conformation with the SCHCHS planes making a dihedral angle of 13 ± 2° with the S₂C  CS₂ plane. The other structural parameters obtained are r_CH = 1.085 ± 0.014 Å and the angel CCH = 123.7 ± 1.5°.     

Luminescence de l'Europium Divalent dans les Fluosilicates MSiF6 (M = Sr,Ba)

Luminescence of Eu²⁺ Ions in Fluosilicates MSiF₆ (M = Sr, Ba) A pure f → f emission is detected in Eu²⁺ doped SrSiF₆ and BaSiF₆. Because of the strong ionic bonding of europium a large gap occurs between the bottom of the 5d band and the ⁶P_7/2 emission level (3000 cm^?1 at 300 K). The emission is very intense under low pressure mercury excitation and decreases slowly with temperature.