Preparation and structure elucidation of 1,6,9,13‐tetraoxadispiro(4.2.4.2)tetradecane

The tricyclic title compound, a symmetrical dispiro oxygen heterocycle, was isolated as a byproduct in the hydrogenation of furfuryl alcohol in the presence of hydrochloric acid. NMR studies and single crystal X‐ray analysis have established the relative stereochemistry of the two ketal carbons. Formation of the observed trans stereoisomer under equilibrating conditions is attributed to the anomeric effect.     

A kinetic study of the air oxidation of pyrogallol and purpurogallin

Pyrogallol (1,2.3-benzentriol, 1 ) reacts with dioxygen in weakly alkaline solutions to form purpurogallin (2,3,4,6-tetrahydroxy-5H-benzocycloheptene-5-one, 2 ) which then reacts to form purpurogalloquinone ( 3 ) which then decays to a product absorbing at 440 nm. The formation of 3 requires 1.5 mol O₂ per mol 1 , and 1.0 mol per mol 2 . No O₂ is consumed during the decay of 3 , and this reaction, being insensitive to O₂ concentrations and the presence of both superoxide dismutase (SOD) and catalase, does not appear to be an oxidation. The first-order rate of decay of 3 decreases with increasing pH. 1 and 3 react at pH 9.0 with a second-order rate constant of ca. 100 M^?1 s^?1. SOD inhibits the oxidation of 1 and 2 . Slight and variable apparent inhibition of the oxidation of 2 and 3 by SOD may be due to trace impurities in 2 , but not contamination by 1 . The peak concentration of 3 is attained more rapidly during the oxidation of 1 than during the oxidation of 2 . A kinetic scheme based on parallel oxidation of 1 by dioxygen and superoxide, and it which the semiquinone of 1 oxidizes 2 , is partially successful in simulating the observed kinetic behavior.     

Data bank: The PE Spectra of Paracyclophanes with Unsaturated Bridges and of Related Molecules

The PE spectroscopic data for a series of [2.2]paracyclophanes with olefinic and/or aromatic bridges, and of a few related molecules are reported, together with tentative assignments based on simple MO models.     

Reply to “determinism,realism, and Stapp's 1985 proof of nonlocality”

It is shown that the objections raised in the cited paper are to features not present in my proof.     

Focused-electron-beam-induced processing (FEBIP) for emerging applications in carbon nanoelectronics

Focused-electron-beam-induced processing (FEBIP), a resist-free additive nanomanufacturing technique, is an actively researched method for “direct-write” processing of a wide range of structural and functional nanomaterials, with high degree of spatial and time-domain control. This article attempts to critically assess the FEBIP capabilities and unique value proposition in the context of processing of electronics materials, with a particular emphasis on emerging carbon (i.e., based on graphene and carbon nanotubes) devices and interconnect structures. One of the major hurdles in advancing the carbon-based electronic materials and device fabrication is a disjoint nature of various processing steps involved in making a functional device from the precursor graphene/CNT materials. Not only this multi-step sequence severely limits the throughput and increases the cost, but also dramatically reduces the processing reproducibility and negatively impacts the quality because of possible between-the-step contamination, especially for impurity-susceptible materials such as graphene. The FEBIP provides a unique opportunity to address many challenges of carbon nanoelectronics, especially when it is employed as part of an integrated processing environment based on multiple “beams” of energetic particles, including electrons, photons, and molecules. This avenue is promising from the applications’ prospective, as such a multi-functional (electron/photon/molecule beam) enables one to define shapes (patterning), form structures (deposition/etching), and modify (cleaning/doping/annealing) properties with locally resolved control on nanoscale using the same tool without ever changing the processing environment. It thus will have a direct positive impact on enhancing functionality, improving quality and reducing fabrication costs for electronic devices, based on both conventional CMOS and emerging carbon (CNT/graphene) materials.     

An effective procedure for the acylation of azaindoles at C-3

Conditions for attachment of acetyl chloride, benzoyl chloride, and chloromethyl oxalate to the 3-position of 4-, 5-, 6-, or 7-azaindoles were explored. Best results were achieved with an excess of AlCl(3) in CH(2)Cl(2) followed by the addition of an acyl chloride at room temperature.