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Competition between hydrogen abstraction and halogen displacement in the reaction of Br with C[H.sub.3]I, C[H.sub.3]Br, and C[H.sub.3]Cl was studied. The hydrogen abstraction and homolytic substitution reactions were found to be competitive for C[H.sub.3]I and the predicted branching fraction to C[H.sub.3]Br was about 13%.

A novel methodology is developed for the evaluation of receptor arrangement in structurally flexible anion chemosensors and is applied to map the binding site of a new pseudocyclic tristhiourea chemosensor. The binding patterns are found to be different for the chemosensors, indicating dissimilarity in the arrangement of the binding sites of pseudocyclic tristhiourea chemosensor and macrocyclic chemosensor.

The mechanism of selective production of methyl chloride by a reaction of methane, hydrogen chloride and oxygen over lanthanum-based catalysts is analyzed. The results have shown that the proposed mechanism has involved changing of the formal oxidation state of surface chlorine from -1 to +1 without any changes in the oxidation state of the underlying metal.

The tunable synchrotron radiation is used to study the total and partial ion yield spectra of CIC(O)SCI in Ar and N2 matrixes. Several reaction channels were identified as a result of the characterization of various photoproducts by their infrared spectra and observed behaviors of infrared absorption as a function of irradiation time.

Analysis of the reaction force for a gas phase S(sub N)2 process of CI and OH through CH3CI + H2O --> CH3OH + HCI is conducted. Although H2O is a less effective nucleophile than OH(super -10), it is preferred to be used as the charge on an ion in this context could distort or mask some of the property variations of interest.

The gas-phase reaction CH3Cl + H --> CH3 + CIH (RI) and CH2CI + H-H (R2) reactions, which proceed by two channels, CI- and H-abstractions, as a model of a more general asymmetrically substituted polyatomic system, CX3Y + A are investigated and potential energy surface for each channel is created. The surfaces are attractive as both channels have an early transition state (reactant-like transition-state).

Ab initio and density functional theory (DFT) calculations are used to examine the mechanisms of reduction and amination of chloromethane by lithium dimethylaminoborohydride (LAB) in the gas phase. The reduction of chloromethane by LAB occurred most readily from a conformation that allowed coordination of the lithium atom to the chloride-leaving group, and the most favorable amination pathway occurred by a backside attack of the nitrogen nucleophile on chloromethane.

The activation energy in the gas phase and the free energy of activation in water solution for the hydrolysis of the monohydrates of methyl chloride (MeCl), tert-butyl chloride (t-BuCl), and 1-adamantyl chloride (AdCl) is computed with the B3LYP/631-G(d) method and the polarizable continuum (PCM) solvation model. There is a fair agreement between the free of activation values computed and the experimental data.

The infrared spectra of the CH3Cl:NO complex isolated in solid neon are investigated detecting most of the vibrational modes of the complex and on the basis of DFT calculations, different geometries are explored for the complex. The weak interaction between NO and CH3CI in CH3Cl:NO is responsible for small shifts of the vibrational mode frequencies of both CH3CI and NO molecules and the most stable structure is of C1 symmetry.

The formation and structure of the CH(sub 3)Cl:H(sub 2)O complex is investigated by neon matrix isolation technique combined with infrared absorption spectroscopy. The complex is found to have a cyclic structure, where the chlorine atom is weakly bonded to one of the hydrogen atoms of water, while the oxygen atom is weakly bonded to one of the hydrogen atoms of CH(sub 3)Cl.

MP2/6-31+G(d,p) calculations are used to analyze the interaction between CH3X (X = F, Cl, or Br) and hydrogen peroxide (HP). Two stable structures involving the formation of a six-membered or five-membered ring are found on the potential energy surface and it is observed that in both structures the molecules are held together by OH...X and CH1...O hydrogen bonds.

The reaction of a formaldehyde radical anion with methyl chloride is an example of a reaction in which a single transition state serves two mechanisms namely, substitution at carbon (Sub(C)) and electron transfer (ET). The reaction is studied using ab initio molecular dynamics at the HF/6-31G(d) level of theory.

An isolate from the enrichment culture is obtained and its physiology is characterized during anoxic and aerobic growth on chloromethane (CM), including the yield, stoichiometry of nitrate and oxygen consumption, chloride and nitrogen gas release and kinetics. It was seen that the Pseudomonas aeruginosa strain NB1 also grew on methanol, ethanol and acetate under denitrifying and aerobic conditions.

The acid-base kinetics of excited 4-methyl-7-hydroxyflavylium (HMF) is straightforward in water, reflecting ultrafast deprotonation of the excited acid and diffusion-controlled protonation of the excited base. A detailed kinetic picture of the initial steps involved in an ultrafast excited state proton transfer at the surface of a typical anionic micelle is presented.

An analysis of the effects of solvation on the pairing of electrons in molecules in a series of the molecules including neutral, anionic, and cationic species and in the Menshutkin reaction between ammonia and methyl chloride is presented here. This comparative analysis has been carried out in the framework of the atoms in molecules theory and the PCM method is used to model the effects of solvation on the solute wave function.

Hydrogen abstraction reactions between chloromethanes and the hydroxyl radical are researched by using ab initio molecular orbital theory. The results obtained from the PMP2 AND QCISD(T) calculations with the larger 6-311G(2df,2p) basis set are in good agreement with the experimental values.

The self-assembly of the nanofibers with built-in donor/acceptor heterojunction upon admission of MeOH, the enantiomerically pure form of chiral amphiphilic porphyrin-fullerene dyad in presence of C[H.sub.2][Cl.sub.2] is reported. The electron and hole mobilities under zero electric field estimated from time-of-flight profiles are comparable to those reported for top-class organic materials with a donor/acceptor heterojunction.

Preparation and characterization of samples of 4,4'-bis(3,3,3-tri-d5-phenylpropynyl)biphenyl, 9,10-bis(3,3,3-tri-d5-phenylpropynyl)anthracene, 1,4-bis(3,3,3-tri-d5-phenylpropynyl)naphthalene, and 4,4'-bis(3,3,3-tri-d5-phenylpropynyl)-1,1'-binaphthyl, are reported. The differences observed in precipitated solid that result in efficient rotational motion in the solvated crystals offer insight for the low pre-exponential factor observed in the disordered crystals.

The gas-phase substitution reactions of methyl chloride and 1,3-dimethyluracil are investigated. The leaving group ability of the N1-deprotonated 3-methyluracil anion relative to the N1-deprotonated 3-methylthymine anion is examined in the context of an enzymatic reaction that has cleaved uracil but not thymine from DNA.

The isotopic studies of the carbene anions that could act as prototypical anions and undergo proton transfer and substitution reactions with chloromethanes are reported. The product ion isotope distributions for the reaction of CHCl*(-) with CH[Cl.sub.3] provide insight into the occurrence of an insertion-elimination mechanism, analogous to neutral carbene processes.

The unexpected phototransformations of 2-alkoxymethyl-5-methylphenacyl chloride or benzoate are analyzed. The high reaction selectivity, controlled by traces of water in the reaction system, is an interesting result, which might be used in organic synthesis.

Liquid-liquid phase transfer catalysis (LLPTC) mechanisms are provided for a displacement reaction where [Q.sup.+] denotes the quaternary catalyst cation (tetraalkylammonium or phosphonium ion), [X.sup.-], the catalyst anion, [M.sup.+][Y.sup.-], the water soluble reagent and RX, the substrate soluble in the organic phase. These colorful and fairly safe experiments can be used to help students get acquainted with the feasibility of extracting some soluble anionic reagents from water into an organic layer.

A variable temperature (super 2)H solid-state nuclear magnetic resonance (NMR) investigation of cryptophane-E: chloroform and cryptophane-E: dichloromethane inclusion complexes is presented. One of the findings showed that the (super 2)H NMR data were complemented by an X-ray diffraction study of the cryptophane-E: dichloromethane structure, which was utilized in the analysis of the NMR parameters.

The mass-resolved resonance enhanced two-photon ionization spectra of jet-cooled benzyl chloride are measured. The internal rotational motion of the chloromethyl group of the jet-cooled benzyl chloride molecule is analyzed by using the one-dimensional free rotor approximation.

Calculations of the potential energy surface for the K + CH3Cl reaction leading to electron transfer from the K atom forming CH3 and Cl(super -) or KCl are reported. The findings indicate that a simple electron jump does not occur with the CH3Cl + K system along a minimum energy pathway.

The 248 nm photo-dissociation of methyl hypochlorite (CH3OCl), an atmospheric chlorine reserve, is examined. The results are similar to the direct dissociation patterns found by other measurement studies of alkyl hypohalites.

Varying degrees of chain end and adaptation disorders are assumed to be the causes of different crystal forms. These forms were examined using the conformational responsiveness of numerous infrared active methyl group vibrations.

Quantum chemical method is used to study the mechanism of the radical-radical reaction C2H3 + CH3 .The results of the study and the analysis of earlier experimental results demonstrate that the reaction of C2H3 + Ch3 proceeds through two distinctly different routes.

The study is on the analysis of the CH...X(super -1) interactions between Y(sub n)H(sub 3-n)CH anions as proton acceptors using the MP2/6-31+G(d,p) method and optimized geometries of these complexes and their vibrational frequencies and intensities are discussed. These shows that they correlate fairly well with the intermolecular distances and to that of hydrogen bonds involving NH groups and also the interaction energies correlate to the deprotonation enthalpies of the CH bond of the proton donors and to the proton affinity of the anions.

A demonstration is done on a newly developed coherent two-dimensional (2D) vibrational spectroscopy, doubly vibrationally enhanced four wave mixing (DOVE-FWM) spectroscopy on a unique model system containing acetonitrile and water.1. The observation suggests that the general microstructure picture of the mixtures with two types of CH3CN species should be improved by involving more than two species and would provide useful information for the design of new 2D DOVE-FWM experiments.