The iodates of scandium

A dihydrate, a monohydrate, and three polymorphs of the anhydride Sc(IO₃)₃ have been prepared and studied. Sc(IO₃)₃·2H₂O was prepared by gel growth and by precipitation and evaporation at room temperature. The γ-anhydride can be crystallized from boiling water or nitric acid solution. The other compounds are formed on heating the dihydrate, which also dehydrates very slowly at room temperature. The α-anhydride is amorphous. The β-anhydride generates second harmonics, with about twice the efficiency of quartz. In addition differential thermal analysis (DTA), thermogravimetric analysis (TGA), infrared absorption, and powder X-ray diffraction results are presented.     

Arsenic speciation by capillary gas-liquid chromatography

Specific environmentally significant arsenic compounds are determined by capillary gas-liquid chromatography. Inorganic (arsenite, arsenate) and organic (monomethylarsonate, dimethylarsinate) arsenicals are measured as the corresponding methylthioglycolate derivatives, which are simultaneously separated on wide-bore borosilicate glass and fused-silica columns under conditions of temperature programming. Inorganic arsenate and arsenite cannot be differentiated by the derivatization technique. Flame-ionization and electron-capture detection are evaluated. A simple and rapid sample preparation procedure is used for water, urine, blood, and tissue.     

Alkylation of ethyl bromomalonate by alkylcobaloximes

Allylcobaloximes react under very mild conditions with ethyl bromomalonate to yield allyl-substituted ethylmalonates in good yield. In the case of crotyl-, 3,3 dimethyl, allyl- and cinnamyl-cobaloximes, the substitution occurs with total rearrangement of the allyl groups. Similar rearrangements are observed during the reactions of propargyl- and allenylcobaloximes with BrCH(CO₂Et)₂ yielding allenyl- and propargyl-malonic esters respectively.     

Photoelectron spectra of uranium(V) in mixed oxides showing characteristic satellite signals

Whereas uranyl compounds at most show electron transfer satellites at 3 eV higher I in the U4f region, mixed oxides containing uranium(V) show a characteristic satellite at 7.9 eV higher I. Uranium-cerium blue and certain U(IV) compounds are also discussed.     

Tritium in Lebensmitteln

In order to test the method of tritium determination and to determine the tritium activity, foods of known origin were investigated. The accuracy of the method over a prolonged period of time is confirmed by the statistical evaluation of the background values and of the counting efficiency. An average value of 600–800 pCi of tritium in one litre of water was found in milk, potatoes and apples. Drinking water contained very different activities of tritium, depending on its origin as ground or surface water. Food samples from the environment of nuclear reactors were not different in their tritium content when compared to those of other origin.     

Preparatory investigations of fast separation for heavy ion reaction products

A method for separation and chemical identification of products formed in nuclear reactions or nuclear decay is to slow down the recoil products in a gas and to transport them to a trap, where a detecting system is arranged. The sources for the recoil products are²⁵²Cf and²²⁴Ra. As transport phase we used nitrogen or argon and added chemical reagents such as methyl and ethyl radicals, chlorine, oxygen, carbon monoxide or methane. The chemical additives lead to selective and fast separation of certain elements. As examples the results of two experiments are presented:²²⁴Ra with ethyl radicals, and²⁵²Cf with chlorine-oxygen-nitrogen mixtures. The registration of the recoil products at the trap was measured as a function of temperature, pressure and composition of the reactive gas.     

Investigations in the field of vinyl ethers and esters of the furan series

Vinyl-furancarboxylate has been synthesized by the reaction of-furancarboxylic acid with acetylene and with vinyl acetate in the presence of various catalysts. The structure of the vinyl ester has been confirmed by IR spectra and by catalytic hydrogenation. The acid and alkaline hydrolyses of vinyl-furancarboxylate have been studied.     

Kettenlängeneffekte in Paraffinen, 4. Mitt.: Synthese von primären Carbonsäuren neben Alkylmalonsäuren aus n-Paraffinen durch Ummetallierung und anschließende Carboxylierung

Zusammenfassung Ausn-Paraffinen lassen sich mit Hilfe des Systems Quecksilberdialkyl/Kalium und nachfolgender Carboxylierung mit CO₂ primäre Monocarbonsäuren neben alkylierten Malonsäuren darstellen. Sekundäre Monocarbonsäuren bilden sich aus Paraffinen dabei höchstens in Spuren. Verzweigte Paraffine reagieren unter den beschriebenen Versuchsbedingungen schwer und stören als Verunreinigungen inn-Paraffinen nicht.Herrn ProfessorAsinger zu seinem 60. Geburtstag herzlichst zugeeignet. F. Korte, W. Klein undE. J. Schmid, Tetrahedron1966, Suppl.8, 93 (1966).     

Synthesis of monoethers by addition of aliphatic diols to bicyclo[2.2.1]hept-2-enes

Addition of aliphatic diols to bicyclo[2.2.1]hept-2-ene and its 5-alkyl-substituted derivatives in the presence of naphthalene-1,5-disulfonic acid leads to the formation of the corresponding bicyclo[2.2.1]hept-2-yl monoethers in high yields.     

Effect of oral pretreatment with antibiotics on the hydrolysis of salicylic acid-tyrosine and salicylic acid-methionine prodrugs in rabbit intestinal microorganisms.

We examined the hydrolysis mechanism of salicylic acid-tyrosine (salicyl-tyrosine) and salicylic acid-methionine conjugate (salicyl-methionine) in rabbits by exploring their behavior following intraduodenal and intracecal administration (72 and 36 mumol/kg, respectively: salicylic acid equivalent). A large amount of salicyl-methionine was absorbed following intraduodenal administration of salicyl-methionine, without being metabolized to salicylic acid in the small intestinal mucosa. On the contrary, salicylic acid was detected in the blood following intraduodenal administration of salicyl-tyrosine, suggesting that salicyl-tyrosine was metabolized in the small intestinal mucosa. After oral pretreatment of rabbits with kanamycin sulfate (6 x 400 mg) or tinidazole (6 x 160 mg), the hydrolysis of salicyl-tyrosine and salicyl-methionine following intracecal administration was inhibited significantly, indicating that the intestinal microorganisms were responsible for the biotransformation of these prodrugs. Furthermore, in rabbits orally pretreated with both kanamycin sulfate and tinidazole, a significant inhibition of salicylic acid formation from salicyl-tyrosine and salicyl-methionine following intracecal administration was observed.