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Abstract: The hydrolytic process of LinB-catalyzed biotransformation of a notorious contaminant [beta]-HCH was investigated in atomistic detail with a combined quantum mechanics/molecular mechanics approach. The Boltzmann-weighted averaging method amended by [...]

Abstract: J.H. van't Hoff's seminal paper variously titled as either: Chemistry in Space, The Placement of Atoms in Space or other with similar wording, depending on the language it was [...]

A [beta]-(1->3)-mannohexaose is synthesized by a block route involving the coupling of two trisaccharides. The comparison of three closely related attempted mannohexaose syntheses has reinforced the affect of subtle matching and/or mismatching interactions on the outcome of convergent oligosaccharide synthesis.

The roles of intra- and intermolecular correlations in cavity formation in n-hexane, contrasting hardsphere solvation in aqueous and nonaqueous solution are addressed.

The study describes the design, synthesis and phosphorylation pattern of the new bicyclo[3.1.0]hexane template that exhibits highly strong and increased chemical and enzymatic stability due to the absence of a true glycosyl bond. The template is found to be extremely rigid that makes it useful for sculpting other carbocyclic nucleosides, which also makes it easier to interact with the herpes simplex thymidine kinase.

The effects of aromatic solvents on the electronic structures and chain conformations of [alpha]-oligothiophenes are studied. The results suggest that radial and spatial distribution of the solutes leads to distortion of the chain conformations in polar and nonpolar solvents as demonstrated by the molecular dynamics (MD) simulations.

The capacitance of monolayer-protected gold nanoclusters (MPCs), [C.sub.PMC], in solution was theoretically reconsidered from an electrostatic viewpoint, in which an MPC was considered as an isolated charged sphere within two dielectric layers, the intrinsic coating monolayer, and the bulk solvent. The model predicted that the bulk solvent provides an important contribution to [C.sub.MPC] and influences the redox properties of MPCs.

The dissociative adsorption and decomposition on a range of metal surfaces of an alkane, an alkene, and an aromatic, all representative of species present in an important technological application, was studied under conditions relevant to selective gas sensing based on solid electrolyte potentiometry. It was found that at 870K, pure polycrystalline Pt surfaces do no discriminate between n-hexane, toluene and 1-butene, however, by varying the composition of polycrystalline bimetallic Pt/Au surfaces, good discrimination between these species can be achieved.

A description is provided on replacements of 5-carboxy for the preparation of 2-substituted 2-azabicyclo (2.1.1) hexanes with halo, amino, phenyl and 2-carboxyethyl substituents. A simplified route to the parent azabicycle involves decarboxylation of the 5-acid with lead tetraacetate in cyclohexane.

Adsorption of N(sub 2) was studied on zeolite H-Y (H-USY), ultrastabilized H-Y, H-mordenite, H-ZSM-5, H-beta, and on sulfated zirconia-titania (SZT) mixed oxide by diffuse reflectance infrared transform spectroscopy. The results revealed that the intrinsic acid strength of the solids followed the order of H-ZSM-5 approximately equal to H-mordenite approximately equal to H-beta > H-USY approximately equal to SZT approximately equal to ultrastabilized H-Y.

The reaction rate of the Diels-Alder reaction between N-ethylmaleimide and 9-hydroxymethylanthrance in CO(sub 2) + ethanol and CO(sub 2) + hexane mixed solvents of different compositions were determined by in situ UV/vis spectroscopy at 318.15 K and different pressures. The result states that at the same temperature the reaction can not be conducted in pure supercritical CO(sub 2) in the highly compressible region due to the solubility limitation of 9-hydroxymethylanthrance in supercritical CO(sub 2) at the lower pressures, while the reaction can be carried out in the highly compressible mixed solvents, and reaction rate is effective by pressure.

Sorption of n-hexane on monodimensional pure silica SSZ-35, CIT-5, ZSM-12 and ZSM-22 zeolites with different pore dimension and on the synthesized ITQ-29 was studied. The theoretical calculations clearly showed the accordance between the orientations of sorbed molecules, which are varied for different zeolites and the heat of sorption of hexane.

Dimethylstannylene (SnMe2) and its subsequent decay to tetramethyldistannene are formed from the 193-nmlaser flash photolysis of 1,1-dimethylstannacyclopent-3-ene in the gas phase and 1,1,3,4-tetramethylstannacyclopent-3-ene in solution. Steady-state photolysis leads to the formation of the corresponding dienes, and in solution, SnMe2 is trapped in reaction with M trimethylstannane (Me3SnH)to afford a product of Sn-H insertion.

The interaction of hexane with amorphous solid water was investigated in terms of the surface diffusion, hydrogen bond imperfections, hydrophobic hydration, crystallization and glass-liquid transition. The results revealed that the structural relaxation commences at the conventional glass-transition temperature but required considerable long aging time.

The reaction of NO2 with toluene, kerosene, and hexane flame soot was studied over the temperature range 240-350 using a low-pressure flow reactor coupled to a modulated molecular beam mass spectrometer. The results show that heterogeneous reaction of NO2 with soot does not significantly influence the oxidative capacity of the atmosphere by producing HONO and consequently OH radicals.

The Kirkwood-Buff theory of solutions is applied to the hexane/cyclohexane/methylbenzoate ternary (MB) ternary system. The volumetric properties of the ternary system were correlated and predicted with the cubic equations of state by soave and Peng-Robinson combined with two simple mixing rules.

The conformational properties of trans-1,4-dichlorocyclohexane (DCC) adsorbed in several zeolites, including completely siliceous ZSM-5, Na-Y and siliceous Y, is examined by using FT-Raman spectroscopy. The results indicate that the conformational behavior of DCC is dependent on the zeolite framework structure, Si/Al ratio, and the charge-balancing cations.

The studies have presented evidence for the simultaneous generation and excitation of the perylene radical cation in a nonpolar solution via a two-photon resonance in the singlet manifold. A comparison also demonstrated that the perylene radical cation in hexane abstracts a hydrogen atom from the solvent on an ultra fast time scale.

A number of 9-anthrylsilanes including ASi(sub n) and ASi(sub n)A are synthesized and their photochemistry is studied. Photoexcited anthryldisilanes exhibit some unique interactions between the sigma(Si-Si) and pi(anthryl)* groups.

The solvation statics and dynamics of coumarin 153 and 102 dyes were studied in hexane-methanol mixtures. The solvation of the coumarin dyes, in ground and in excited electronic states, exhibited a nonlinear solvatochromic shift in the methanol mole fraction.

A comparative study of a long-chain alkanol at the water-vapor and water-hexane interfaces using X-ray reflectivity to highlight significant differences between these two interfaces is presented. The results revealed that at the water-hexane interface, the density in the headgroup region is 10-15% greater than either bulk water or the ordered headgroup region found at the water-vapor interface.

Incorporation of copper(II) ion into fluorinated porphyrin to form the metalloporphyrin CCu(tpfpp)) was kinetically investigated using bis(beta-diketonato)copper(II) complexes (CuL2) in ScCO2 and n-hexane. The reaction mechanisms in both the solvents seemed to be similar.

The kinetics and mechanism of three amines with two 1,1-diarylsilene derivatives have been studied in hexane, acetonitrile and tetrahydrofuran (THF) solution using laser flash photolysis techniques. The reactions were slower in THF as compared to the MeCN solution.

The isomerization of tricyclo[3.1.0.0(super 2,6)]hexane to 1,3-cyclohexadiene was studied with the help of ab initio calculations at the multiconfiguration and single-configuration levels of theory. To describe the potential energy surface of the reaction properly, a multiconfiguration based wave function is necessary.

The density functional theory used to examine a hypothetical five-step catalytic cycle for Bronsted-mediated fission of an all-trans n-alkane is discussed. The predicted intermediates varied with catalyst acidity.

Capillary condensation of near-saturated vapors of n-Hexane/perfluoro-n-hexane mixtures in a model pore formed by the gap between two mica surfaces are studied using a modified surface force apparatus. It is observed that the composition of a mixed condensate can show a significant time-dependence in the initial stages of condensation.

Time-resolved infrared (TRIR) and computational method were used to examine the solvent dependence of the singlet triplet energy gap of 2-naphthyl(carbomethoxy) carbene. Solvent and geometry effects on the entropy of carbenes can offset differences due to spin multiplicity.

Research is conducted on 1-(9-anthryl)-3-(4-N,N-dimethylaniline) propane (ADMA), which is known to form an emissive 'sandwich heteroexcimer' (SH) in the excited state. In conclusion, ADMA is identified as an excellent probe of dielectric enrichment in complex environments.

The new asymmetric catalytic Strecker reaction of achiral N-phosphonyl imines is described and excellent enantioselectivity are achieved by using primary free natural amino acids as catalysts and [Et.sub.2]AlCN as nucleophile. The studies have presented the novel use of nonvolatile and inexpensive [Et.sub.2]AlCN in asymmetric catalysis and the N-phosphonyl protecting group has enabled simple product purification to be achieved by washing the crude products with hexane.

A highly efficient synthetic methodology for tri-N-annulated hexarylenes from easily available N-annulated perylenes, which is favored by the oxidative ring fusion driven by DDQ/Sc[(OTf).sub.3] is reported. The combination of [pi]-[pi] stacking interactions and dipole-dipole interactions observed for the tri-N-annulated hexarylene dyes which exhibit remarkably large dipole moments might favor the formation of highly ordered supramolecular structures that result in enhanced charge carrier mobilities.

The mild and efficient Pt[Cl.sub.2]-catalyzed cycloisomerization of 1,6-enynes containing a heteroatom substituent at the propargylic position is described. The reactions is able to produce 1-alkenylbicyclo[3.1.0]hexanes in good to excellent yields or 2-(bicyclo[3.1.0]hex-1-yl)acetaldehydes in moderate yields.

Nucleophilic displacements of 5(6)-anti-bromo substituents in 2-azabicyclo[2.1.1]hexanes(methanopyrrolidines) are described. The presence of electron-withdrawing F, OAc, [N.sub.3], Br, or SPh substituents in the 6-anti-position has slowed bromide displacements at the 5-anti-position.

The mechanisms involved in the crossed [2+2] cycloaddition reactions of 1-phenylcyclopropene and 1-bromo-2-phenylcyclopropene are discussed. The various steps and procedures involved in the reactions are also discussed.

The synthesis of two target bicyclo[3.1.0]hexane nucleosides, locked as north and south conformers as well as a flexible analogue built with a cyclopentane ring in presence of cytidine deaminase (CDA) as catalyst is described. The results demonstrated that the binding preference of CDA for a south sugar pucker is in agreement with the high-resolution crystal structures of other CDA inhibitors bound at the active site.

The theoretical calculations on aggregation of nBuLi/lithium aminoalkoxide superbases in gas phase and solution are described. The results have provided insights to the aggregation of organolithium compounds in solution and are useful for examining other systems.

The formation of fiberlike micelles in hexane with a very narrow weight-average distribution of lengths and the nature of their fragmentation following exposure to ultrasound are described. The results have shown that these fibers also rupture according to Gaussian fragmentation model and display a fracture rate that is very sensitive to fiber length.

Manganese(III) acetate dihydrate-mediated cycloadditions of 5,5-dimethyl-1,3-cyclohexanedione and 1,3-cyclohexanedione to various 1-(pyridine-2-yl)-enones to obtain trans-2-acyl-3-aryl/alkyl-2,3,6,7-tetrahydro-4(5H)-benzofuranone derivatives is reported. The cyclization reaction carried out under solvent-free ball-milling conditions exhibited good to excelled yields with extremely high diastereoselectivity and unexpected regioselectivity.

The article discusses a new approach, where in the light from a mercury vapor high-pressure lamp is employed to induce the photolytic decomposition of [alpha]-diazo acetamides in hexane and in non-conventional media. The lactams obtained in the process are shown to exhibit excellent diastereoselectivities.

The preparation of dark orange trans, trans-[[([Me.sub.3]SiCC)[(dmpe).sub.2]Cr].sub.2]]([mu]-[N.sub.2]).hexane by reaction of trans-[(dmpe).sub.2]Cr[Cl.sub.2] (dmpe = 1,2-bis(dimethylphosphino)ethane) with one equivalent of LiCCSi[Me.sub.3] and one equivalent of nBuLi in THF under a dinitrogen atmosphere is reported. The results obtained from density functional theory revealed that oxidation of the molecule could lead to weakening of the dinitrogen triple bond.

The equilibrium molecular dynamics simulation results for polyhedral oligomeric silsesquioxanes (POSS) monomers dissolved in liquid normal hexane at 300 K and at 400 K are reported.