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Arynes (aromatic systems containing, formally, a carbon-carbon triple bond) are among the most versatile of all reactive intermediates in organic chemistry. They can be 'trapped' to give products that are [...]

BACKGROUND: Computational modeling of the absorption, distribution, metabolism, and excretion of chemicals is now theoretically able to describe metabolic interactions in realistic mixtures of tens to hundreds of substances. That [...]

This experiment performed was to determine the effect of the length of incubation time on the generation of benzene from ascorbic acid and potassium benzoate in Sierra Mist Free. The results would provide useful information on storage methods for soda which might allow people to reduce their benzene intake from soda, thus decreasing their carcinogen accumulation and possibly lowering their risk for developing associated cancers. A headspace gas chromatography and mass spectrometry method was used for the analysis of benzene. Quantitation was preformed using Agilent Enhanced Chem Station D.01.02. A calibration curve was generated by creating dilutions of benzene in deionized water. The range of detection was between 0.52 ng/mL and 20.0 ng/mL. Each sample of Sierra Mist Free was prepared for incubation by adding 10 mL of Sierra Mist Free to a headspace vial. There were 4 samples per group. Groups 1-8 were incubated at 50 °C for a certain amount of time over a 14 day period. Group 9 was the control group, incubated at room temperature. The data showed that no benzene was generated in any sample for any given period of incubation time at 50 °C or room temperature. The hypothesis, which stated that samples incubated at for a longer time at 50 °C would generate more benzene than samples incubated at 50 °C for a shorter period of time or at room temperature, was rejected, and the null hypothesis, which stated that incubation time would have no effect on the amount of benzene generated, was accepted., Introduction Anyone who indulges in Coke, Sprite, Mountain Dew, or other sodas generally recognizes the negative effects of drinking carbonated drinks: for example, the caffeine, the high sugar, the empty [...]

BACKGROUND: Studies relying on outdoor pollutants measures have reported associations between air pollutants and birth weight. OBJECTIVE: Our aim was to assess the relation between maternal personal exposure to airborne [...]

BACKGROUND: Recent evidence has shown that humans metabolize benzene more efficiently at environmental air concentrations than at concentrations > 1 ppm. This led us to speculate that an unidentified metabolic [...]

BACKGROUND: Careful evaluation of the quality of human observational studies (HOS) is required to assess the suitability of HOS for quantitative risk assessment (QRA). In particular, the quality of quantitative [...]

BACKGROUND: Benzene is a human carcinogen. Exposure to benzene occurs in occupational and environmental settings. OBJECTIVE: I evaluated variation in benzene-related leukemia with age at exposure and time since exposure. [...]

The synthesis, isolation, and characterization of hexakis(4-(N-butylpyridylium))benzene as both a hexacation and neutral molecule are reported.

Photochromic systems can convert light energy into mechanical energy, thus they can be used as building blocks for the fabrication of prototypes of molecular devices that are based on the photomechanical effect. Hitherto a controlled photochromic switch on surfaces has been achieved either on isolated chromophores or within assemblies of randomly arranged molecules. Here we show by scanning tunneling microscopy imaging the photochemical switching of a new terminally thiolated azobiphenyl rigid rod molecule. Interestingly, the switching of entire molecular 2D crystalline domains is observed, which is ruled by the interactions between nearest neighbors. This observation of azobenzene-based systems displaying collective switching might be of interest for applications in high-density data storage. scanning tunnel microscopy | molecular switches | photochromic system | data storage

The systematic studies of pressure dependence of Raman spectra of benzene/C[O.sub.2] two-component system is carried out at different temperatures and compositions. The observation of the shift of the peak composition of the inhomogeneous bandwidth suggests that inter-molecular interaction between benzene and C[O.sub.2] molecules grow at low temperatures.

Abstract -- The mechanism of the electrochemical oxidation of iodide in the presence of 4-toluenesulfinic acid was studied in an aqueous solution using cyclic voltammetry and controlled-potential coulometry. The results [...]

The oxidation of several fluoroanilines with potassium ferricyanide and potassium hydroxide is described. In this oxidation, the major products are fluoroazobenzenes. In the case of 2-fluoro-substituted anilines, heterocyclic fluorophenazines were obtained in low to moderate yields. The optimal conditions for the reaction and the mechanism are presented. Key words: oxidation, fluoroanilines, fluoroazobenzenes, fluorophenazines.

Using molecular dynamics (MD) simulations of a single solute in water the hydration structures of the hydrophobic solutes benzene and cyclohexane were investigated. Three-dimensional maps of the density of the water O and H atoms surrounding either benzene or cyclohexane were generated from the simulation data.

The effect of aromatic swelling agents on the pore geometry and pore size of mesoporous M41S materials is investigated, where benzene and 1,3,5-trisubstituted aromatic compounds are used as swelling agents. Benzene is incorporated and immobilized close to the surface of the micelle, whereas the more hydrophobic trisubstituted aromatic compounds are located in the hydrophobic core of the micelle, where they retain some mobility.

The threshold photoelectron spectrum of benzene has been recorded up to 26.5 eV photon energy under high-resolution conditions using synchrotron radiation and employing the penetrating-field threshold electron collection method. By means of a direct comparative study with a recent HeI pbotoelectron spectrum of benzene of equally high resolution, numerous autoionization effects are observed in the formation of the ionic band systems of benzene in the outer valence ionization region in the threshold photoelectron spectrum. The Rydberg states responsible for these effects are identified. Autoionization does not appear to play a role in the formation of the two lowest-energy, innervalence bands of [C.sub.6][H.sup.+.sub.6]. Key words: threshold photoelectron spectroscopy, photoelectron spectroscopy, benzene, ionization, autoionization, Rydberg states.

Oil exploration causes huge volumes of oily wastewater and produced waters show a wide range of salinities with spilled brine inhibiting plant growth. A highly enriched halophilic culture was established with benzene as the sole carbon source using brine soil obtained from an oil production facility and community structure analysis showed that Marinobacter spp. was a dominant member of the enrichment.

The interaction energies of the alkaline-earth-metal dication/benzene complexes were calculated at the MP2 level using the 6-311G-basis set. The calculations of benzene under an electric field show that the electric field produced by the diction is a cause of the C-C bond elongation in the alkaline-earth-metal dication/benzene complexes.

The ultraviolet and infrared spectra of the C6H6-(C4H2)(sub n) complexes with n=1 and 2 were formed and studied in a supersonic expansion. A T-shaped structure is deduced for the complex, with the C4H2 centered, end on, over the benzene ring.

Study of the electrochemistry of a novel organic-inorganic material in which 4,4-bipyridinium units (BP) are covalently attached to the walls of a periodic mesoporous organisilica (PMO) of the MCM-41 type is reported. It was observed that the electrochemical response of regular mesoporous organosilica of the MCM-41 type containing bipyridinium units covalently attached vary significantly for as-synthesized material, BP@PMO.

Density-functional theory calculation, Monte Carlo simulations and thermodynamic perturbation theory calculations were carried out to analyze the differences between the solvation of phenol and phenoxy radical in benzene and acetonitrile. The theoretical calculations in this study indicated that the differences between the solvation which enthalpies of phenol (PhOH) and phenoxy radical (PhO(super .) in both benzene and acetonitrile are smaller.

Experimental evidence for a strong polar ordering induced by wire poling under high electric field conditions in the amorphous pDR1M azobenzene polymer is reported. A comparative study of the electronic spectra of a DR1 solution in chloroform and of an unpoled, a poled and a thermally depoled film is discussed.

The results of the research conducted on van der Waals complexes of aniline and 4-aminobenzonitrile with polar solvents formed in a supersonic jet is reported. It also reports the solvatochromism studies of all substituted benzenes and napthalenes.

The voltage sensitivity of hemicyanine dyes ANNINE-6 and ANNINE-5 with anellated benzene rings and without free CC single and double bonds is studied in Retzius neurons from Hirudo medicinalis. The Annine dyes are the most efficient fluorescent probes of neuronal activity on the basis of a well-defined physical mechanism.

Well-resolved spectra of styrene-methanol binary clusters SM(sub n), with n = 1-9, is obtained by the resonant two-photon ionization technique. It is proposed that the interaction of the methanol molecules with the olefin center of styrene promotes the proton transfer from the styrene dimmer to the hydrogen-bonded methanol cluster.

A pulse radiolysis study of six parasubstituted benzenediazonium salts is carried out in strongly acidic aqueous solution , where the principal reductant is the hydrogen atom. The characteristics of the corresponding hydroxyl adducts of the diazonium salts are described.

The absolute absorption spectrum of the benzyl radical in the visible region measured by ring-down spectroscopy in the visible region measured by cavity ring-down spectroscopy is presented. The absorption cross sections reported would facilitate the quantification of the benzyl radical in future kinetic studies.

The study presented provides explanations to the addition of the first and the second hydrogen atoms to benzene. The methods used for this purpose are density functional theory and generalized gradient.

The ab initio maximization and electrostatic potentials are calculated for numerous disubstituted benzenes. A considerable six parameter correlation between logP and the calculated descriptors for a training set of representative disubstituted benzenes is presented.

The aromaticity of benzenes annelated to small rings is examined using ab initio molecular orbital calculations. The aromaticity of benzene is explained in terms of the similar electronic states for six pi bonds from the configuration interplay localized molecular orbital CASSCF analysis on the basis of ab initio measurements.

The thin films of a benzylic amide macrocycle, the common component of a wide class of mechanically interlocked molecules, are prepared by vapor deposition on Au(111). The films are characterized by monochromated X-ray photoelectron spectroscopy (XPS) and high resolution electron energy loss spectroscopy (HREELS).

Research has been conducted on the thermal or photochemical ethyl diazoacetate reaction with benzene to produce the isomeric cycloheptatrienes mixture. The details of this reaction are discussed.

Research has been conducted on the star- and trefoil-shaped polyethynyl aromatic structures representing all-carbon network graphdiyne model substructures. The synthesis and characterization of these aromatic structures are discussed.

The electronic structure of benzene adsorbed on single-domain Ge(100-(2*1) and on a single-domain Ge monolayer grown on SDi(100)-(2*1) is investigated by angle-resolved ultraviolet photoemission spectroscopy (ARUPS). The weekly bound benzene species can only be observed on Ge(100) but not on Si(100) or Ge/Si(100) and the reason for this bonding is because it is based on kinetic hindrance of saturation of the chemisorbed species.

A study of the potential energy surfaces (PESs) of the interaction of benzene with Pt and Pt2 with the help of density functional B3LYP computational level using the Ha-Wadt relativistic core potential is presented. The resulting stable structures, which are formed are rationalized in terms of molecular orbital patterns.

Results reveal that some electron-deficient enynes can be highly reactive substrates in the palladium-catalyzed homo-benzannulation reactions. Research describes the introduction of functional cyano- alkoxycarbonyl groups to the benzene ring, which aids in an efficient regioselective synthesis of functionalized polysubstituted benzenes.

Research is presented describing the study of cycloalkane solvent holes to determine reversible reactions.

It has been possible to measure powder neutron and synchrotron X-ray diffraction patterns from zeolite ZSM-5 containing levels of adsorbed benzene of around 3.4 molecules per unit cell and 7.6 molecules per unit cell.

A 2H NMR study on clathrates with a polycyano-polycadmate host is presented. A number of models of guest molecular motions are suggested based on their molecular and crystal structures.

The many ways in which the scanning tunneling microscope (STM) can investigate the adsorption and unimolecular reaction of unsaturated six-membered ring molecules are discussed. The STM can prompt a chemical reaction and characterize the initial and final states on the atomic scale.

Issues concerning the role of potential CO2/F intermolecular interactions in solution are considered. This research involved measuring the T1 values of perfluorobenzene, benzene and perdeuteriobenzene in CO2 as a function of temperature and pressure.

It has been possible to analyze the reaction pathways and the energetics for the direct hydroxylation of methane and of benzene that arise on the surface of Fe-ZSM-5 zeolite. The 'two-step concerted mechanism' should be widely used in analyzing how hydrocarbon hydroxylations are catalyzed by transition-metal oxides.

Issues concerning the use of molecular dynamics simulations to calculate the relative hydration free energies of organic molecules are presented.