Ion cyclotron resonance studies of some reactions of C+ ions

Product distributions and rate constants for the reaction of ground state C⁺ ions with O₂, NO, HCl, CO₂, H₂S, H₂O, HCN, NH₃, CH₄, H₂CO, CH₃OH, and CH₃NH₂ have been measured. Rate constants were obtained using ion cyclotron resonance trapped ion methods at JPL, and product distributions were obtained using a tandem (Dempster-ICR) mass spectrometer at the University of Utah. Rapid carbon isotope exchange has also been observed in C⁺-CO collisions.     

Mean-field versus microconvection effects in nanofluid thermal conduction

Transient hot-wire data on thermal conductivity of suspensions of silica and perfluorinated particles show agreement with the mean-field theory of Maxwell but not with the recently postulated microconvection mechanism. The influence of interfacial thermal resistance, convective effects at microscales, and the possibility of thermal conductivity enhancements beyond the Maxwell limit are discussed.     

Calorimetric determination of the heats of formation of lanthanide monosulfate complexes in D2O1

Heats of formation of rate-earth monosulfate complexes have been measured calorimetrically for the ions La³⁺, Sm³⁺, Tb³⁺, and Er³⁺, in D₂O and H₂O solvents. Within the limits of experimental error there is no evidence for a solvent isotope effect on the heat and entropy changes of these complexation reactions.This paper was abstracted from W.D.W.'s Ph.D. dissertation, May 1973.     

The thermolysis of the neocupferron chelates of yttrium and the rare earth elements

The thermolosis curves of the neocupferron chelates of yttnum, lanthanum, cerium(III), cerium(IV). praseodymium, neodymium, samarium and gadolinuim were determined. It was found that the ehelates were stable up to 8o°, with the oxide levels being reached at 460–750°.     

Synthesis of 1,5-dideazariboflavin

1,5-Dideazariboflavin, an analog of riboflavin containing the original conjugated double bond system between positions 1 and 5, was synthesized by the condensation of 4,5-dimethyl- N-ribitylanthranilaldehyde and the sodium salt of 2,4,6-piperidinetrione.     

The thermal decomposition of the 2-methyl-8-quinolinol (8-hydroxyquinaldine) chelates of scandium,thorium, uranium (VI) and the rare earth elements

The thermal decomposition of the 2-methyl-8-quinolinol (8-hydroxyquinaldine) chelates of scandium, thorium, uranium(VI), yttrium and the rare earth elements was studied on the thermobalance. It was found that the scandium and uraniurn(VI) chelates can lose the extra molecule of solvation by thermal decomposition. The thorium chelate was found to be the most stable of all the chelates studied. The temperature limits for the chelates and the minimum oxide level temperatures are given.     

Method for the direct determination of available carbohydrates in low-carbohydrate products using high-performance anion exchange chromatography

An improved method for direct determination of available carbohydrates in low-level products has been developed and validated for a low-carbohydrate soy infant formula. The method involves modification of an existing direct determination method to improve specificity, accuracy, detection levels, and run times through a more extensive enzymatic digestion to capture all available (or potentially available) carbohydrates. The digestion hydrolyzes all common sugars, starch, and starch derivatives down to their monosaccharide components, glucose, fructose, and galactose, which are then quantitated by high-performance anion-exchange chromatography with photodiode array detection. Method validation consisted of specificity testing and 10 days of analyzing various spike levels of mixed sugars, maltodextrin, and corn starch. The overall RSD was 4.0% across all sample types, which contained within-day and day-to-day components of 3.6 and 3.4%, respectively. Overall average recovery was 99.4% (n = 10). Average recovery for individual spiked samples ranged from 94.1 to 106% (n = 10). It is expected that the method could be applied to a variety of low-carbohydrate foods and beverages.     

Proton controlled intramolecular communication in dinuclear ruthenium(II) polypyridine complexes

The synthesis and characterization of two dinuclear ruthenium polypyridyl complexes based on the bridging ligands 5,5'-bis(pyridin-2' '-yl)-3,3'-bis(1H-1,2,4-triazole) and 5,5'-bis(pyrazin-2' '-yl)-3,3'-bis(1H-1,2,4-triazole) and of their mononuclear precursors are reported. The dinuclear compounds have been prepared by a Ni(0) catalyzed coupling of a mononuclear ruthenium(II) polypyridyl complex containing a brominated triazole moiety. Electrochemical and photophysical studies indicate that, in these dinuclear complexes, the protonation state of the bridge may be used to tune the intercomponent interaction between the two metal centers and that these species act as proton driven three-way molecular switches that can be read by electrochemical or luminescence techniques.