Über die Konzentrationsabhängigkeit der Viskosität bei organischen Hochpolymeren

Zusammenfassung Es wird eine Korrekturformel zur 8. Potenzformel von Philippoff-Heß vorgeschlagen, die auch die Fälle gut wiedergibt, wo die einfache 8. Potenzformel ebenso wie andere Viskositätsgleichungen bisher versagten. Im einzelnen wird die Gleichung geprüft an folgenden bisherigen Ausnahmen: Cellit in Eisessig (Philippoff-Heß), polymere-Hydroxydekansäuren in sym-Tetrachloräthan(Kraemer-von Natta), polymere Polystyrole in Benzol (Dane). In jedem Falle stellen diek-Werte gute Konstanten dar.Die charakteristische Viskositätskonstantek zeigt eine lineare Zunahme mit dem Molekulargewicht der Polymerhomologen.Die Temperaturabhängigkeit vonk unda wird geprüft.     

Spectroscopic Study of Reaction of Propargyl Bromide with Pyridine

Pyridine was reacted with propargyl bromide to obtain the dibromide [C₅H₅NCH = CHCH = CHCH = CHC₅H₅N]^{2 +} 2Br^-. The effect of the vinyl group on its UV spectrum is qualitatively interpreted using the results of nonempirical quantum-chemical calculations (basis HF/6-31G^*).     

NMR Study of Structural Changes in Humic Acids of Meadow Soddy Soils

Quantitative and qualitative changes in humic acids of meadow soddy soils, occurring under the action of various fertilizer systems, were studied by ¹³C and ³¹P NMR.     

Constituents of holothuroidea.9. Isolation and structure of a new ganglioside molecular species from the sea cucumber Holothuria pervicax

A new ganglioside molecular species, HPG-7 (1) was obtained from the polar fraction of the chloroform/methanol extract of the sea cucumber, Holothuria pervicax. On the basis of chemical and spectroscopic evidence, the structure of 1 was determined, and the major component was 1-O-[alpha-L-fucopyranosyl-(1-->4)-(N-acetyl-alpha-D-neuraminosyl) - (2-->11)-(N-glycolyl-alpha-D-neuraminosyl)-(2-->4)-(N-acetyl -alpha-D- neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-(2S,3S,4R)-2-[(2R)-2- hydroxytetracosanoylamino]-14-methyl-hexadecane-1,3,4-triol. This is the first report on the isolation and structure elucidation of trisialo-ganglioside from sea cucumber. 1 showed neuritogenic activity toward the rat pheochromocytoma cell line, PC-12 cell.     

High-Sensitivity Determination of Hydrocarbon Impurities in Arsine by Reaction Gas Chromatography

It is shown that the results of determining methane in high-purity arsine by reaction gas chromatography can be overestimated by more than two orders of magnitude. This overestimation is caused by the formation of methane as a side product of the reaction. Cryogenic preconcentration at the injection stage is proposed to improve the accuracy of determination of methane, and the cryofocusing of impurity hydrocarbons is proposed to improve separation. Detection limits of (3–10) × 10^–6 vol % are achieved for C₁–C₅ hydrocarbons.     

Thermochemistry of Dissolution of Glucose in Binary Systems N-Methylmorpholine N-Oxide Monohydrate-Aprotic Solvent

Glucose enthalpies of solution in binary systems N-methylmorpholine N-oxide monohydrateaprotic solvent at 75°C are measured.     

Stabilization of Graphite Nitrate by Intercalation of Organic Compounds

New thermally stable intercalation compounds of graphite were obtained by the further intercalation of a series of organic compounds into graphite nitrate. The stabilization is explained by the formation of hydrogen bonds between the protonated form of the modifying substance and neutral surrounding molecules.