A simple method for the manufacture of flat,glass capilary tubing for gas chromatography

Summary A simple procedure has been developed for the production of flat, glass capillary tubing.     

The mixing time of the giant component of a random graph

We show that the total variation mixing time of the simple random walk on the giant component of supercritical and is . This statement was proved, independently, by Fountoulakis and Reed. Our proof follows from a structure result for these graphs which is interesting in its own right. We show that these graphs are “decorated expanders” — an expander glued to graphs whose size has constant expectation and exponential tail, and such that each vertex in the expander is glued to no more than a constant number of decorations. © 2014 Wiley Periodicals, Inc. Random Struct. Alg., 45, 383–407, 2014     

Beyond Charge Balance: Counter‐Cations in Polyoxometalate Chemistry

Polyoxometalates (POMs) are molecular metal‐oxide anions applied in energy conversion and storage, manipulation of biomolecules, catalysis, as well as materials design and assembly. Although often overlooked, the interplay of intrinsically anionic POMs with organic and inorganic cations is crucial to control POM self‐assembly, stabilization, solubility, and function. Beyond simple alkali metals and ammonium, chemically diverse cations including dendrimers, polyvalent metals, metal complexes, amphiphiles, and alkaloids allow tailoring properties for known applications, and those yet to be discovered. This review provides an overview of fundamental POM–cation interactions in solution, the resulting solid‐state compounds, and behavior and properties that emerge from these POM–cation interactions. We will explore how application‐inspired research has exploited cation‐controlled design to discover new POM materials, which in turn has led to the quest for fundamental understanding of POM–cation interactions.     

Maximal smoothness of the anti-analytic part of a trigonometric null series

We proved recently (C. R. Acad. Sci. Paris, Ser. I 336 (2003) 475–478) that the anti-analytic part of a trigonometric series, converging to zero almost everywhere, may belong to L² on the circle. Here we prove that it can even be C^∞, and we characterize precisely the possible degree of smoothness in terms of the rate of decrease of the Fourier coefficients. This sharp condition might be viewed as a ‘new quasi-analyticity’. To cite this article: G. Kozma, A. Olevski??, C. R. Acad. Sci. Paris, Ser. I 338 (2004).     

Cu-superconductors in organic catalysis I. Isomerization and hydrogenation of allyl alcohol on YBa2Cu3O7?x

On the superconductor YBa₂Cu₃O_7–x between 150 and 300°C, allyl alcohol is isomerized to propionaldehyde (70%) and hydrogenated to 1-propanol (30%) in hydrogen.     

Enantiomeric enrichment of partially resolved N-methyl-amphetamine

The enantiomeric enrichment of N-methyl-amphetamine (MA) was tried by eight different preparative separation methods. The enrichment process was also studied by thermoanalitical methods (DSC,TG). There is no enantiomeric enrichment during fractional distillation and selective extraction of the liquid base. The enantiomeric mixture of MA·HCl can be enriched by crystallization or by sublimation. The most effective enrichment can be achieved by fractional crystallization or distillation of the reaction mixture after partial salt formation with hydrochloric acid. The separation is less effective in case of fractional steam distillation and selective extraction when the enantiomer and the racemate are distributed between two liquid phases. This supports the general experience that having a solid phase in the system makes enantiomer separation more efficient.This revised version was published online in November 2005 with corrections to the Cover Date.     

Simple Synthesis of 3‐Oxopropanenitriles via Electrophilic Cyanoacetylation of Heterocycles with Mixed Anhydrides

A simple and efficient method for the synthesis of 3‐oxopropanenitriles from variously substituted heterocyclic compounds via direct electrophilic cyanoacetylation is described. A series of heterocyclic 3‐oxopropanenitriles ( 2a , 2b , 2c , 2d , 2e , 2f , 2g , 2h , 2i , 2j , 2k ) have been synthesized using mixed anhydride (acetic or trifluoroacetic anhydride:cyanoacetic acid) in the presence of Mg(ClO₄)₂·2H₂O as catalyst. This method can be extended also for the cyanoacetylation of electron poor aromatic compounds.