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A study examines the synthesis of a series of new tetrameric sugar derivatives, one of which demonstrates highly pronounced hydrogelation properties. Detailed spectroscopic, thermal, and microscopic characterization of the resultant gel is provided together with the effect of pH and addition of salts to it.

A study examined efficient monomer and excimer emission from various donor-acceptor substituted phenylethynes (PE) with time-resolved fluorescence measurement during the pulse radiolysis in benzene. The formation of PE in the singlet excited state and the excimer state could be interpreted by the charge recombination between the PE radical cation and the PE radical anion, which are generated initially from the radiolytic reaction in benzene.

Combined electron transport and Raman studies on the reaction of u-bromobenzene diazonium tetrafluoroborate directly with singe and networks of SWNT transistors are discussed. It is found that metallic tubes on an average have higher reactivity toward diazonium reagents.

The design of homogeneous catalysts based on Ir and other late transition metal complexes using O-donor ligands like acetylacetonate (aca), tropolone, aryloxides, catechols, hydroxyaetophenone to stabilize the complexes to the reaction conditions needed for generating functionalized products is discussed. The outcome of the studies helps to utilize, design new, more effective, thermally protic-and oxidant-stable O-donor catalysts for hydrocarbon conversion.

The structure of a thin zone-cast film of the hexa-n-dodecyl-substituted hexa-peri-benzocovonene (HBC) was investigated using grazing incidence X-ray diffraction is discussed. It is found that the relatively long side chains of dodecyl were in an ordered interdigitated state.

A new phosphine-free palladacyle catalyst was prepared from benzyl oxazoline in high yield and fully characterized. With it as catalyst, hydrophenylation reactions of a wide range of bicyclic alkenes, not only norbornene and norbornadiene but also oxa- and aza-bicyclic alkenes, with iodobenzene proceeded smoothly under aerobic condition without exclusion of water.

5'-Aziridinoadenylates of the form aziridine adenylate and related nitrogen mustard variant is constructed using a novel variation of the Mitsunobu reaction. A highly effective synthesis of such molecules that is amenable to aziridine diversification as well as elaboration of the base moiety to afford 'bumped' cofactor mimics compatible with 'hole' bearing mutant proteins is presented.

The long, rigid ligands 1,4-bis[(3-pyridly)enthynyl]benzene and 1,4-bis[(4-pyridly)ethynyl]benzene are used in the synthesis of 10 new organic-inorganic coordination frameworks, each of them adopting different structural motifs. Synthesis, single-crystal x-ray structure determination, and spectroscopic and thermogravimetric analyses are presented.

The syntheses of N-Tfa and N-Fmoc-alpha-amino ketones containing N-heterocycles and benzene using N-(Tfa-and Fmoc-alpha-aminoacyl)benzotriazoles under the Friedel-crafts conditions are achieved. Full preservation of chirality is suggested by HPLC.

The ligand based reduction chemistry of (EPh)(super -) ligands in a metallocene environment is compared to the sterically induced reduction chemistry of the (C5Me5)(super -) ligands in (C5Me5)3Sm by synthesizing complexes like, (C5Me5)2Sm(EPh) (E=S, Se, Te) and treating them with substrates reduced by (C5Me5)3Sm, cyclooctatetraene, azobenzene, phenazine. These benzene chalcogenolate complexes were identified by X-ray crystallogarphy.

A detailed study of the kinetics of the reaction between 2-chloro-5-nitrotrifluoromethylbenzene and 2-phenylpropionitrile anion, under phase-transfer catalysis (PTC), is performed under several conditions. Kinetic data is explained by means of an interfacial mechanism that involves the deprotonation of the adsorbed nucleophile precursor followed by its catalyst-mediated extraction to the organic phase.

A detailed wavelength-scanned surface-enhanced Raman excitation spectroscopy (WS SERES) study of benzenethiol adsorbed on Ag nanoparticle arrays, fabricated by nanosphere lithography (NSL), is presented. The WS SERES spectra are correlated, both spatially and spectrally, with the corresponding localized surface plasmon resonance (LSPR) spectra of the nanoparticle arrays.

The oxidation of benzaldehyde and several of its derivatives to their carboxylic acids by cis-[Ru(super IV)(bpy)(sub 2)(py)(O)(super 2+)(Ru(super IV)=O2, bpy is 2,2'-bipyridine), cis-[Ru(super III)-OH(super 2+), and [Ru(super IV)(tpy)(bpy)(O)](super 2+)(tpy is 2,2':6'2''-terpydine) in acetonitrile and water is investigated. A benzoate intermediate is observed as an intermediate with [Ru(super IV)(tpy)(bpy)(O)](super 2+) as the oxidant.

Synthesis of thieno[2,3-f:5,4-f]bis-[1]benzothiophene and thieno[3,2-f:4,5-f]bis[1]benzothiophene, the anti and syn isomers of a pentacyclic compound consisting of alternating thiophene and benzene rings is reported. It is found that the anti isomer, the ribbon like embedding of three thiophenes units leads to a near-planar molecule with favorable pi-pi stacking behavior in the solid state.

Calculations were performed using strictly atomic benzene-p-orbitals and p-orbitals that are allowed to delocalize, on naphthalene, acenaphthylene, pyracylene and many organic compounds. The results show that cyclopenta-fusion does not extend the pie system in the ground state and the five-membered rings act as peri-substituents.

Ab initio calculated geometries and van der Waals radii are used as crude metrics to quantify the relative degree of steric crowding in the molecules tert-butylbenzene, tert-butyl chloride, and tert-butyl iodide. All of these molecules have sterically hindered CH oscillator in the sense that they possess hydrogen atoms, which are separated from proximal atoms to which they are not chemically bound by less than the sum of their van der Waals radii.

An investigation of the photochemical properties of photoinduced omega-bond dissociation in p-benzoylbenzyl phenyl sulfide (BBPS) in solution is conducted by time-resolved EPR and laser flash photolysis techniques. BBPS is demonstrated to undergo photoinduced omega-bond cleavage to yield the p-benzoylbenyl radical (BBR) and phenyl thiyl radical (PTR) at room temperature.

A theoretical and experimental study is performed on the structure and deprotonation of benzohydroxamic acid (BHA). Details of the calculations at the RHF/cc-pVDZ level, refined by the B3LYP/AUG-cc-pVDZ method are discussed.

A study on the release of iron from ferritin by aceto- and benzohydroxamine acids was done as a function of the chelator concentration, pH, and presence or absence of urea. The results obtained show that both aceto- and benzohydroxamic acid remove iron from ferritin despite the greater size of benzohydroxamic acid compared with the ferritin channels which indicates the flexibility of these channels.

The local aromaticity of the six-membered rings in three series of benzoid compounds, namely, the [n]acenes, [n]phenacenes, and [n]helicenes for n = 1-9, are assessed by means of three probes of local aromaticity based on structural, magnetic, and electron delocalization properties. For [n]acenes, the analysis shows that the more reactive inner rings are more aromatic than the outer rings, while for [n]phenacenes and for [n]helicenes, the analysis shows that the external rings are the most aromatic.

The synthesis and full characterization of a series of donor-and acceptor-functionalized nonplanar tetrakis(phenylethynyl)benzenes and their planar bis(dehydrobenzo[14]- and [15] annuleno)benzene counterparts are described. Computational studies of each system were performed to provide further insights into the energy levels and electronic transitions present.

The holographic recordings in azobenzene-containing amorphous polymers (AP) and polymer-dissolved liquid-crystalline composites (PDLCC) with two waves that have orthogonal linear polarizations were investigated. Only linear photobirefringence was induced in AP, while both linear and circular birefringences were induced in PDLCC.

The palladium-catalyzed liquid-phase reaction of benzyl alcohol to benzaldehyde was investigated in the presence and absence of oxygen by attenuated total reflection infrared (ATR-IR) spectroscopy. The occurrence of the hydrogenolysis of the C-O bond of benzyl alcohol and formation of toluene indicates that Pd was present in a reduced state Pd(super 0) even in the presence of oxygen, in agreement with the dehydrogenation mechanism of alcohol oxidation.

The first experimental observation of a pecular behavior in the isotropic phase of liquid crystals by means of (super 2)H NMR is reported. The two five-ring banana-shaped mesogens, the 1,3-phenylenebis-{4,4'(11-undecenyloxy)benzoyloxy} benzoate (Pbis 11BB) and its 4-chloro homologue (C1Pbis11BB), selectively deuterium labeled on their central rings, are the main subject of investigation.

Complexes are formed in the gas-phase between Pb(super 2+) and a wide range of ligands using a pickup technique in association with high-energy electron impact ionization with oxygen, nitrogen, sulfur, and phosphorous complexes consisting of benzene and argon being the coordinating atoms. It is now possible to explore a wide range of molecular environments in association with Pb(super 2+) and coordination is examined in the presence of O-, S-, N-, and P-donor ligands.

A study is conducted to examine H(sub 2)S-benzene dimer as the simplest model of sulfur-Pi interactions. Analysis of the interaction using symmetry-adapted perturbation theory, along with potential energy curve for rotation of the H(sub 2)S unit relative to the benzene ring, suggests that the sulfur-Pi interaction is an electrostatic attraction between the partial positive hydrogen in H(sub 2)S and the negatively charged Pi electrons of benzene.

The FTICR mass spectrometry study shows that the reactions of YC(sub 2)(super +) and LaC(sub 2)(super +) with benzene produce three main series of cluster ions. The study of gas-phase ion-molecule reactions of yitrium- and lanthanum-carbide cluster ions YC(sub n)(super +) and LaC(sub n)(super +) with benzene and cyclohexane reveal ligand effect on the gas-phase reactivity of these metal-carbide cluster ions.

The hydride, fluoride, and pentafluorophenylmetallocenes are isolated and characterized by X-ray crystallography. A monomeric metallocene hydride of cerium undergoes H/F exchange with fluoroaromatics is showed and DFT calculations provide details about the relative activation barriers for the reaction pathways.

Diarylazines were reacted with 1,2-dehydrobenzene (o-benzyne) to give 10-amino-3-substituted-9(10H)-acridinones. On the other hand, 1,1,2,2-tetracyanoethylene was reacted with diarylazines through Michael addition to yield 5-arylpyrazolidine-3,3,4,4-tetracarbonitriles. On reacting the same azines with dibenzoylacetylene, pyridazine derivatives were obtained via a Diels--Alder reaction. Key words: diarylazines, 1,2-dehydrobenzene, tetracyanoethylene, dibenzoylacetylene.

A new class of dendrons and dendrimers containing azobenzene units were designed and synthesized with the convergent method. Photochemical isomerization experiments revealed that all of the dendrons and dendrimers undergo trans-cis isomerization by irradiation or heating.

The one-photon mass-analyzed threshold ionization (MATI) spectroscopy of bis(n(super 6)-benzene)chromium is reported. Their ionization potentials, from photoionization efficiency spectra, show the gradual decrease as the cluster size gets larger, down to value of 5.02 eV for n=9.

Different theoretical procedures for assessing intramolecular H-bond were applied to di-substituted benzenes. The results showed that the intramolecular H-bond enthalpies based on the isothermic reaction method may be unreliable.

Density functional theory calculations for molecular electronic structure and a green function method for electron transport were used to calculate from first principles the molecular conductance of benzene connected to two Au leads through different anchoring atoms-S, Se, and Te. It was found that the molecule-lead coupling, electron transfer and conductance all depend on the adsorption site, lead orientation, and local contact atomic configuration.

A series of branched poly(6-azulenylethenyl)benzene derivatives consisting of a central benzene ring surrounded by acetylene-bridged 1,3-bis(n-hexyloxycarbonyl) azulene arms is investigated by physical and theoretical methods. Their optical and electrochemical features are explained with the help of calculations regarding their pi nature and extension of the lowest unoccupied molecular orbitals (LUMOs), the key factors that modulate their properties.

An efficient synthetic route to prepare a new series of aza-substituted analogues based on the 1,4-bis(phenylethynyl)benzene moiety was established. The pyrimidine moiety was incorporated into the linear molecules to probe the possibility of dipolar interactions that can control the crystal packing.

Structure of the unusual anthelmintic pyrrolobenzoxazine terpenoid natural product CJ-12662 was confirmed by X-ray crystallography and partial synthesis from 2-chloronitrobenzene. The pyrrolobenzoxazine moiety was synthesized using dye-sensitized photooxygenation of a tryptophan derivative.

A reorientation phenomenon that takes place inside confined smectic-C (SmC) domains in a phase-segregated Langmuir film is reported. The process involves a sign reversal of the splay texture following the transient displacement of the central defect.

Photoionization tandem-mass spectrometry of selectivity deuterium labeled precursor molecules were used to probe the structure of protonated benzene. Studies suggest that the observations might be obscured by a combination of isobaric impurities, metastable-ion contributions, and artifact signals.

Quantum chemical calculations of G2M level of theory were used to elucidate the detailed mechanisms for the reactions of phenyl radicals with ethylene (R1), vinyl radicals with benzene (R2), and H atoms with styrene (R3). Theoretical molecular and adjusted energetic parameters were used to calculate the total rate constants and product branching for reactions R1-R3 by weak collision master equation/RRKM analysis and transition state theory with Eckart tunneling corrections.

A diffraction grating with a large diffraction efficiency has been inscribed on an azobenzene-containing polymer thin film, electrically poled and characterized using spatially resolved Raman confocal microscopy and near-field scanning optical microscopy. Linear and nonlinear polarized microscopic measurements have been performed on a grating.

The liquid-phase catalytic oxidation of benzene was carried out under mild reaction conditions over Cu-impregnated zeolite catalysts (Cu/NaX, Cu/HX, Cu/NaY, Cu/HY, Cu/NaZSM-5, Cu/HZSM-5, Cu/Namordenite, Cu/Hmordenite, and Cu/Hbeta) using both molecular oxygen and ascorbic acid as the oxidant and the reducing reagents, respectively. Phenol was exclusively produced as the oxidation product and no other product was detected. Among the catalysts tested in this study, the Cu/HY catalyst had the highest activity for phenol formation. H-type zeolites were more effective supports for phenol formation than the corresponding Na-type ones. The yield of phenol was found to increase with the simultaneous increase in the amounts of both the supported Cu and the added ascorbic acid. The Cu species supported on HY began to elute as [Cu.sup.2+] species in the solvent from the HY support with the initiation of the oxidation of benzene. The dissolved [Cu.sup.2+] species were reduced to form precipitated [Cu.sup.1+] species during the benzene oxidation. The homogeneous Cu species dissolved from the Cu/HY catalyst were thus suggested as mainly contributing to the phenol formation. The precipitated [Cu.sup.1+] species that had no activity for the benzene oxidation were found to be regenerated in their oxidation activity toward phenol formation by calcination of the [Cu.sub.1+] species in flowing air, although parts of the Cu species were found to be converted to aggregated CuO during the calcination. Key words: supported copper catalysts, zeolite, oxidation, benzene, phenol, oxygen, ascorbic acid.

Linear and angular benzobisoxadisiloles can serve as the precursors for stepwise generations of the synthetic equivalents of 1,4- and 1,3-benzdiynes where benzynes generated were trapped as [4+2] cycloaddition products. The results are revealed through the corresponding iodonium triflate intermediates, which can be viewed as the synthetic equivalents of benzdiynes.

Benzyl-substituted carbanions produced by photodecarboxylation of ketoprofen derivatives are examined in basic aqueous and DMAO solutions. Product studies, combined with kinetic measurements from laser flash photolysis, have allowed the determination of absolute rate constants for protonation and intra-S(sub N)2 reactions leading to five- and six-membered ring cyclizations.

Density functional theory is utilized to determine whether the addition of O2((super 3)sigma(sub g)) to 2-oxepinoxy radical, a proposed intermediate in the unimolecular decomposition of phenylperoxy radical, followed by unimolecular rearrangement and decomposition results in the formation of experimentally detected C1-C5 products through oxidative combustion of benzene.

The infrared spectrum and conformational flexibility of benzil are studied by matrix-isolation FTIR spectroscopy, supported by DFT calculations. It is observed that the low-frequency, large-amplitude torsion around the C-C central bond strongly affects the structural and spectroscopic properties exhibited by the compound.

The influence of a chiral gelator molecule, N,N',N'-tris (S)-(3,7-dimethyloctyl)benzene-1,3,5-tricarboxamide ((S)DO3B), on the structure in the formation of supramolecular polymers and viscoelasticity are examined in an organogel system consisting of a racemic mixture of the gelator molecule, N,N',N'-tris(3,7-dimethyloctyl)-benzene-1,3,5-tricarboxamide (DO3B) and n-decane.

The relation between aromaticity and the substituent effect for the benzene ring in a series of its m onosubstituted derivatives is examined. The stabilization energies derived from homodesmotic reaction schemes differ to a greater extent due to the imbalanced effects such as strain, conjugation, repulsive interactions.

Surface relief gratings are inscribed on azobenzene polymer films with the help of a pulselike exposure of an Ar(super +) laser. The conclusion states that the rate of trans-cis isomerization increases with the intensity of the inscribing light and in the dark it is equal to the rate of thermal cis-trans isomerization.

Variable-temperature (super 2)H NMR investigations are carried out to study the molecular behavior of predeuterated benzene in the inclusion compound with tris(1,2-dioxyphenyl)cyclotriphosphazene. A quantitative analysis of the experimental data is achieved by appropriate computer simulations taking into account various motions of the benzene guests.

Fluorescence resonance energy transfer (FRET) measurements, using BIDS (4- benzamido-4'-isothiocyanostilbene-2,2'-disulfonate) as a label for the disulfonic stilbene site and FM (fluorescein-5-maleimide) as a label for the cytoplasmic SH groups of band 3 (AEl) is investigated. The involvement of two relatively distant parts of the AEl protein in transport function suggests that the transport mechanism requires coordinated large-scale conformational changes in the band 3 protein.