Metal moles

Hsu JWP, Loo YL, Lang DV, Rodger J (2003) Nature of electrical contacts in a metal-mole-cule-semiconductor system. J Vac Sci Technol B 21 1928... 

Previous thermal analysis studies had indicated that while Sb203 did not react directly with DBDPO, there was some evidence that the reaction of a polymer substrate with the Sb203 generated a species which was very reactive (23), and that this product was antimony metal (Sb°). Therefore, simple mixtures of DBDPO with powdered antimony, bismuth and zinc metals (mole ratio of bromine to metal of 3 1) were pyrolyzed and the extent of reaction determined by CGC. 

Abstract A preconcentration method using Amberlite XAD-16 column for the enrichment of aluminum was proposed. The optimization process was carried out using fractional factorial design. The factors involved were pH, resin amount, reagent/metal mole ratio, elution volume and samphng flow rate. The absorbance was used as analytical response. Using the optimised experimental conditions, the proposed procedure allowed determination of aluminum with a detection limit (3o/s) of 6.1 ig L and a quantification limit (lOa/s) of 20.2 pg L, and a precision which was calculated as relative standard deviation (RSD) of 2.4% for aluminum concentration of 30 pg L . The preconcentration factor of 100 was obtained. These results demonstrated that this procedure could be applied for separation and preconcentration of aluminum in the presence of several matrix. 

Application of 2 fractional factorial design allowed the optimization of the enrichment procedure for the determination of aluminum by AAS. The optimum conditions were found to be 4 of pH, 10 of reagent/metal mole ratio, 15 luL of elution volume and 1 mL min of flow rate. 

In the highly purified state, the ratio of moles of metal/moles of enzyme becomes an integral number, attesting to the specificity of the inter-... 

Table 2 Relative rates of aryl group interchange between triphenylphosphine and tris-para-tolylphosphine cat yzed by group 8 transition metals. Reaction conditions 1000 ppm of metal catalyst phosphine metal mole ratio = 20 100 psi ofH2 C3H6(l l)...

Theoretical work fnnction on electrical transport (tunneling) in metal-mole-cule-metal jnnctions indicates that junction impedance is significantly affected by the properties of the metal-molecule contacts. Specifically, the presence of barriers to electron (or hole) injection leads to drops in electrostatic potential at the metal-molecule interface, resulting in contact impedances. Various methods are currently available for probing the electrical conductance of discrete molecules or clusters of molecules bridged between metal or semiconductor electrodes to understand how the structure and electroiuc properties of molecules and their associated contacts affect the current-voltage (I V) characteristics observed for the junction [133,136,146-161]. 

Wold, D.J. and Erisbie, C.D., Fabrication and characterization of metal-mole-cule-metal junctions by conducting probe atomic force microscopy, J. Am. Chem. Soc. 123, 5549-5556, 2001. 

For yttrium, cerium, neodymium and praseodymium over 90% of the element was converted into phosphate at a phosphate to metal mole ratio close to unity. A threefold excess of phosphate was required in the case of lanthanum and ytterbium. Amongst the elements studied so far, gadolinium and erbium required the highest P04 RE " mole ratio for complete conversion into phosphates, around 4 and 5, respectively. 

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