Search

Research has been conducted on the N (sub)2 H (sub)5 (super)+ oxidations by Br (sub)2, Cl (sub)2 and BrCl. The use of stopped-flow and pulsed-accelerated-flow methods is discussed.

A study was conducted to analyze bromine peroxide, mixed bromine and chlorine peroxides, and their isomers using wave functional and density functional theory techniques. The form and relative stability of the species were examined using optimized geometries, harmonic frequencies, relative energies and isodesmic heats of formation. Results indicated the effectiveness of the methods in determining bond lengths.

A study was conducted to evaluate a possible mechanism for the release of both chlorine and bromine containing photolabile compounds from sea-salt aerosol by investigating the uptake and reaction of ClNO2 on pure water, NaBr and NaBr/NaCl solutions using a moistened wall flow tube equipped with a differentially pumped quadrupole mass spectrometer. ClNO2 is formed at yields of more than 90% by reaction of N2O5 on aqueous chloride solutions and on dry-humidified NaCl surfaces. Results of the study are discussed.

A study was conducted to analyze the adlayer structures of chlorine, bromine and iodine on the Cu(111) surface by in-situ scanning tunneling microscopy in solution and ex-site low-energy electron diffraction in ultrahigh vacuum. A commercial Cu(111) single-crystal disk was utilized as the substrate for electrochemical, in-situ scanning tunneling microscopy. Results indicated that compression in the adlyers of chlorine and bromine on Cu(111) correlated with the differences in their van der Waals diameters.

A study was conducted to analyze the reactions of selected azaarenes with chlorine and bromine radicals in water. A high-pressure mercury lamp was utilized for irradiation while several solvents of different polarity were analyzed for extraction studies. Results indicated a competition of two reactions in the reaction behavior of halogen radicals with aromatics. Findings also showed that the reactivity of different carbon atoms with halogen radicals supported the charge gradient resulting from the substitution of a CH group by a nitrogen atom.

The structural and dynamic properties of chlorine and bromine ions and atoms in xenon clusters were investigated. A search method based on a genetic algorithm was utilized to determine the lowest energy structure of Xe(sub n)Y (Y = Cl(super -), Br(super -) and Br) microclusters. Experimental results showed that both Cl and Cl(super -) were found inside the Xe cluster while Br and Br(super -) adsorb onto the cluster surface. It was also found that for most clusters, the lowest energy structures of the lighter halogen appear to be independent of its charge state.

Br and Cl NMR experiments were conducted to determine the structural and electronic properties of Cl- and Br- anions distributed within the cavities of sodium,silver,halo sodalite lattices. Results indicate the presence of a strong shielding of the Br and Cl nuclei in the soladite lattices where interaction between adjacent Ag4Br and Ag4Cl clusters were facilitated. A difference between the dynamic properties of Br- anions in the Na4Br encapsulated clusters was also detected.

Brominated benzenes and other bromoaromatic compounds react with hypochlorites in biphasic systems leading to the formation of chloroaromatics. The presence of the phase-transfer catalyst, tetra-n-butylammonium bisulfate, contributes to the rate of bromobenzene conversion to chlorobenzene. The replacement process involves chlorine atom intermediacy and halide molecule pi-complexes. In addition, the reactions that contain phase-transfer catalysts exhibit slight oxygen and light sensitivity.

A variety of reactions of sea salt with gases lead to the formation of chlorine and bromine atom precursors that photolyze to generate reactive halogen atoms. Chlorine atoms generally lead to ozone formation in the troposphere, while bromine atoms destroy ozone.

The photochemistry of CH(sub 2)BrCl is studied using laser-induced wave pocket propagations on coupled multistate CASPT2 potentials calculated for the electronic ground and low-lying excited states, as a function of two reaction coordinates corresponding to the two halogen eliminations. The results of the study indicate that the lowest excited state, with character (super 1)(n sigma *), is strongly repulsive in both the C-Br and C-Cl directions.

Quasi-relativistic ab initio calculations are performed for (super 199)Hg nuclear magnetic shielding constants and chemical shifts in a series, which included spin free relativistic (SFR) term and magnetic interaction (RMI) term. It is important to increase in the flexibility of the innermost and outermost orbitals of the basis set.

A study was conducted to explain the mechanism of the two-channel hydrogen abstraction reactions from methanol by chlorine and bromine atoms (CH3OH+Cl and Br). The ab initio calculations revealed that both reactions proceeded via formation of intermediate complexes. Results revealed that, unlike the CH3OH+F reaction, all transition states of the two reactions were discovered above respective molecular complexes energy levels at all levels of the molecular orbital theory.