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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.

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 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).

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.

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.

A number of different theoretical methods, along with extended basis sets, have been used to analyze the thermochemistry of the benzynes. It was shown that multireference second order perturbation theory correctly reproduces the singlet-triplet energy splittings of the benzynes.

This research focuses on a comparison of the electronic properties, vibrational frequencies, binding energies, and the geometries of the minimal energy conformers of the C6H6-AlX3 and the corresponding C2H4-AlX3 systems.

Issues concerning the microstructure of C16TABr micelles with solubilized benzene are discussed. It was found that, on benzene addition, the micelles become marginally elongated microemulsion droplets.

A generalized approach to refractive indices calculation with quantum mechanical models has been discussed. Results indicate that refractive indices for benzene in the gas and liquid phase agree with the limited experimental data.

Temperature dependent rate constants and product branching fractions have been used for the reactions of atmospheric plasma cations with benzene. A schematic reaction coordinate diagram of the primary dissociation channels of C (sub)6 H (sub)6 (super)+ is presented.

An UV-vis and FTIR study of the interactions of betacarboline with benzene, naphthalene and phenanthrene has been carried out. The authors suggest stabilization of the complexes by the hydrogen-bonding interaction between NH betacarboline group and the pi-delocalized benzenoid substrate electrons.

The solid-state nuclear magnetic resonance spectroscopy was used to study the jump reorientation dynamics of benzene molecules adsorbed on Ag-Y zeolite. Results revealed a broad benzene jump angle distribution and the existence of multiple benzene reorientation rates for site exchange among different local environments. The activation energy for the molecular reorientation motions of benzene site-jumping dynamics in Ag-Y zeolite was estimated to be 34 +/= 2 kJ/mol.

The pressure dependence of the rotational mobility of benzene was investigated in dilute solutions of water and methanol at various temperatures and pressures. The hydration shell was found to be vulnerable to pressure at higher temperatures. At lower temperatures, a strong hydration shell was observed, in which a benzene molecule can reorient with little pressure effect.

A study has been conducted to elucidate quantitatively the ionization dynamics of Bz-HF and to determine the origin of preference of the reaction channels using the direct ab initio dynamics calculations. Findings have revealed that the Bz-HF complex has no excess energy at the initial step of the trajectory calculation. It has also been found that HF/3-21G multidimensional potential energy surface exists throughout in the trajectory calculations.

Research was conducted to examine in detail the vibrational assignment of liquid bromobenzene. To separate the integrated intensities due to various transitions, the imaginary molar polarizability spectrum was fitted between 3240 and 140 cm-1. The calculation of the transition moments and squares of the dipole moment derivatives with respect to normal coordinates for bromobenzene was carried out. Comparison with other experimental results for benzene-d was performed.

Research was conducted to examine the synthesis of the silica mesoporous material MCM-48 which was carried out in a 5 L autoclave. X-ray powder diffraction and 29Si MAS NMR were used to monitor the progress of the synthesis which was formed by an intermediate phase whose conversion ito the cubic phase was triggered by condensation of the silanol groups. Powder X-ray diffraction, nitrogen adsorption and subcritical organic vapor adsorption isotherms and breakthrough curves were employed to study the mechanical stability of MCM-48.

The single charging integral method was used to measure the infinitely dilute residual chemical potential for methane, ethane, propane and benzene in water. The estimates for the absolute infinite-dilution chemical potentials for the four hydrocarbons were in good agreement with experimental values, indicating that the method is robust, accurate and efficient for calculating differences in residual chemical potentials.

The chemisorption of benzene on Si(111)-7x7 was investigated using high-resolution electron energy loss (HREEL) spectroscopy and thermal desorption spectroscopy. Both physisorption and chemisorption of benzene occur at 110 K. The chemisorbed benzene desorbs molecularly at 349 and 363 K, possibly attributed to benzene desorption from faulted and unfaulted sides of the unit cell, respectively. HREEL results show the presence of both sp(super 2) and sp(super 3) carbon atoms in chemisorbed benzene as well as the formation of C-Si bond. These affirm the di-sigma bonding of benzene to two adjacent adatom and rest atom on Si(111)-7x7, producing a 1,4-cyclohexadiene-like structure.

Benzene molecules that have undergone absorption tend to form pi-complexes with an adsorption enthalpy of 42+-4 kJ/mol and are characterized by Ca2+ molecules in interlayer spaces. These molecules have also been found to exhibit small angle wobbling and rapid discrete jumps along the C6 axis. Under high temperature, however, these molecules undergo large angle wobbling, with corresponding increase in enthalpy and entropy rates.

A relation representing solid-liquid coexistence in solvent crystal-noncrystalline polymer systems is deduced theoretically and is expressed as a function of concentration in terms of the interfacial free energy and crystal size. A melting point depression analysis based on the deduced relation was performed by using experimental results on lightly chemically cross-linked natural rubber-benzene systems. The relation is revised by introducing the effects of the application of chain elasticity by swelling, a temperature and composition parameter and the entanglement concept.

Benzene (C6H6, C6D6, 13C6H6) and naphthalene (C10H8, C10H8) molecules were trapped in solid normal hydrogen, normal deuterium, neon and argon. The triplet states of the aromatic hydrocarbons were excited by steady-state light sources, and their X-band electron spin resonance spectra were recorded. Lifetimes in those states were also measured. Possible catalysis of the o-H2 to p-H2 conversion by these triplet states were was examined.

A study was conducted to analyze the fluctuating charge, fluctuating dipole and combined models for substituted benzenes. A general linear response framework containing both fluctuating charges and dipoles was formulated. An electrostatic model was then completed by adding fixed charges fit to the zero-field quantum chemical electrostatic potential. Results indicated the accuracy of the many-body response of the peptide models and was in good agreement with ab initio computations of the changes in the electrostatic potential.

Nitrosation by NO+ of benzene and toluene proceeds through initial formation of intermediate electron donor-acceptor pi-complexes. This was confirmed by ab initio molecular orbital and B3LYP hybrid Hartree-Fock/density-functional calculations in a computational study of the roles of pi- and sigma-complexes, especially their electron donor-acceptor character, in such aromatic nitrosations. Results showed good agreement between calculated pi-complex geometries and energies and experimental data.

A study was conducted to analyze the interaction between water and hexafluorobenzene. The premise that the oxygen atom functions as a Lewis base in the water-hexafluorobenzene system was examined. Experimental results indicated that the dimer is formed with a binding energy of about -2 kcal/mol. Findings also showed that the rotational motion of the water molecule around the C2 axis is nearly free.

A study was conducted to analyze the molecular mechanism of the delivery process of benzene derivatives from water to the lipid bilayer phase. A site-selective nuclear magnetic resonance method was utilized to carry out the analysis. Results indicated that the benzene derivatives penetrate into the bilayer within a few minutes after injection and are delivered deeply into the bilayer interior in the order PrBe > BzOH.

A study was conducted to determine the driving forces and the guest orientation for the complexation of alpha and beta-cyclodextrins (CD) with mono and 1,4-disubstituted benzenes. Novel equations were utilized to carry out the study. Results indicated that van der Waals force has a critical function in alpha-CD complexation and that hydrophobic interactions have major roles in beta-CD complexation.

Electron spin resonance (ESR) spectroscopy and electron nuclear double resonance resonance (ENDOR) spectroscopy are used to examine the radical cations of methyl-substituted benzene generated in halocarbon matrices by X-ray irradiation at 77 K. Results of the ESR and ENDOR spectroscopy show that radical cations are dominated by large axially symmetric hyperfine splitting due to methyl-group protons. Experimental and theoretical evidence also showed that radical cations of toluene and p-xylene had a more stable type of state than o-xylene and m-xylene.

The pi-cation interactions between benzene and alkali-metal cations were investigated using ab initio molecular orbital and density functional calculations. The relative energies predicted by the MP2 calculations were found to be different from those at the RHF level. Results also showed that the interactions are strong enough to compete with other coordinating donor groups such as alcohols, amines and ethers.