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The synthesis of a photoinduced charge transfer (PCT)-based 1,3-alternate calix[4]crown fluoroionophore containing two cation recognition sites, a crown ether ring and two facing pyreneamide groups, is reported. The wavelength shifts in both fluorescence and absorption spectra upon addition of [Cu.sup.2+] have shown that [Cu.sup.2+] interacts with the nitrogen atoms of the amide groups, resulting in a PCT mechanism.

The synthesis and characterization of a new chemical entity, 1,1-difluoro-1-trimethylsilanyl methylphosphonic acid (DFTMP), an NMR reagent for assessing the near-neutral pH of biological samples are presented. It is shown that the use of DFTMP, in conjunction with a pH-invariant chemical shift reference standard makes in situ pH measurement trivial in NMR experiments conducted in aqueous solution.

The Lewis base mediated carbon-carbon bond forming reactions between pentafluorophenylsilanes and iminium cations were studied theoretically and experimentally. Pentafluorophenylsilanes group exerts a considerable stabilizing effect on a pentacoordinate silicon intermediate and the magnitude of this effect is comparable to that of fluorine and it might also serve as a transferable nucleophilic group toward carbon electrophiles.

A one-pot synthesis of fluorescent 2,5-dihydro-1,2,3-triazine derivatives from a cascade rearrangement sequence in the reactions of 1,2,3-triazolium-1-aminide 1,3-dipoles with propiolate esters is presented. X-ray crystallographic studies and UV absorption spectra studies showed a significant Stokes shift of ca. 200nm, which indicates the potential for biological labeling experiments.

A 12-step synthesis of difluorodimethylproline derivative (S)-1 from commercially available trifluoroacetaldehyde methyl hemiacetal followed by a classical chemical resolution, provided enantiomerically pure 4,4-difluoro-3,3-dimethylproline derivative. The process dispenses with hazardous fluorination reagents, and gives an overall yield greater than 28%.

XeCu covalent bonding found in the complexes XeCuF and XeCuCl were characterized by Fourier transform microwave spectroscopy supported by MP2 ab initio calculations. The valence molecular orbitals with significant shared electron density between Xe and Cu and negative local energy densities at the XeCu bond critical points were predicted.

A systematic, theoretical investigation on structure-property correlations in polyfluorenes (PFs) derived from the chain morphology, oligomer length and chemical substituent is presented. The results estimated the energy gaps of the PFs by extrapolations from excitation energies of oligofluorenes up to 21 fluorenone units.

Regioselecive nucleophilic aromatic substitution of an o-fluorine occurs to afford fluorine-substituted o-phenylene-bridged bis(anilido-aldimine) compounds. Fluorine-substituted complexes shows significantly higher turnover frequencies (TOF) than the unfluorinated analogues for C[O.sub.2]/(cyclohexene oxide) copolymerization.

The application of molecular modeling to study problems related to the packing and conformation of oligofluorene molecules in the solid state is described. The simulations have shown that this configuration is sterically and energetically unfavorable so that formation of an excimer following optical excitation appears to be unlikely.

The pressure dependence of recombination reaction between Cl + FC(O)O + M --> FC(O)OCl + M is investigated at 296 K. It is determined that the reactions are expected to have a negligible impact on stratospheric ozone levels.

A series of 9,9'-spirobifluorene-bridged bipolar compounds DnAm bearing various n:m ratios for triarylamine (D) versus 1,3,4-oxadiazole-conjugated oligoaryl moiety (A) are synthesized to determine the corresponding photoinduced electron transfer (PET) property. Comparisons are made between the experimental and theoretical approaches to understand the PET for the titled systems.

A study to measure the interfacial tension to the hexane solution of 1H,1H-perfluorononanol (FDFC9OH) and its omega-hydrogenated analogue, 1H,1H,9H-perfluorononanol (HDFC9OH) against water as a function of total molality and composition of mixture at 298.15 K under atmospheric pressure is performed. The results indicate that the Gibbs energy of adsorption (G(super H,E)) value is negative in the gaseous state and is positive and increases with decreasing interfacial tension in the condensed state.

A series of new monosubstituted phenylcyanoximes, containing F, Cl, and Br atoms at the 2,3, or 4 positions and their monovalent TI complexes were synthesized and structurally characterized. The crystal structures of the compounds revealed the coexistence of planar cis-syn and cis-anti isomers in the same crystal for H(3F-PhCO), nonplanar trans-anti for H(2Cl-PhCO), and anti configurations for h(4Cl-PhCO) molecules in the solid state.

(super 1)H, (super 19)F, and (super 7)Li pulsed gradient spin-echo (PGSE) NMR measurements for a series of salts are reported. It is shown that (super 1)H, (super 19)F diffusion data for a selection of small, medium, and large BF4- salts in THF solution suggest that THF generally promotes strong ion pairing.

Spherical calcium dioleate particles were used as AFM (atomic force microscope) probes to measure interaction forces of the collector colloid with calcite and fluorite surfaces. The AFM force between the calcium dioleate sphere and the mineral surfaces does not agree with the Derjaquin-Landau-Verwet-Overbeek (DLVO) prediction.

A composite coupled cluster theory CCSD(T)-based approach with extrapolation to the complete basis set limit was used to compute geometries, normal-mode frequencies, atomization energies, and heats of formation for XeF(super +), XeF(super -), XeF2, XeF4, XeF5(super -), and XeF6. Evidence is presented for the fluxionality of XeF6 caused by the presence of a sterically active, free valence electron pair on Xe.

Multireference configuration interaction with singles and doubles (MR-CISD) calculations is performed for the optimization of conical intersections and stationary points on the fluoroethylene excited-state energy surfaces. The photodynamics of the system is discussed based on topological features of these reactions.

The effect of keto defects in fluorene units on the performance of organic field-effect transistors (OFETs) is examined on the basis of fluorene end-capped fused bithiophenes (BFTT) and biphenyl end-capped fused bithiophene oligomers(BPTT). A density of trap sites [N(sub t)] of around 2.7 x 10(super 15) cm(super -3) was found for the BPTT film due to the formation of keto defects after 6 h of UV irradiation.

A combination of transient kinetic and nuclear magnetic resonance (NMR) studies that product release rate-limiting in the activation of the prodrug 5-fluorocytosine (5FC) by cytosine deaminase (yCD), which involve many steps. The transient kinetic and NMR results suggest that the release of 5FU is rate-limiting in the activation of the prodrug 5FC by yCD and may involve multiple steps.

The electrochemistry and radical ion annihilation electrogenerated chemiluminescence of spirobifluorene-bridged bipolar systems containing 1,3,4-oxadiazole-conjugated oligoaryl and triarylamine substituents were investigated. The stability of the oxidized spirobifluorene was improved by functionalization with triaryl centers.

The first room-temperature catalytic hydrodefluorination of aliphatic carbon-fluorine (C-F) bonds is demonstrated. An unconventional method of C-F bond activation is utilized for the process that relies on the abstraction of F(super -) by an electrophilic silylium species.

The first tetrafluoroborate compound with XeF2 coordinated to a metal center, [Cd(XeF2)](BF4)2, was synthesized. [Cd(XeF2)]-(BF4)2 is shown to be in equilibrium with XeF2 and Cd(BF4)2 in a HF.

A complementary method for performing one-pot hydrostannation/Stille reactions with catalytic amounts of tin is developed. The use of the organotin fluorides allows for removal of most tin byproducts by a straightforward combination of filtration and extraction.

Microwave rotational spectroscopy is used to detect and characterize XeAuF in the gas phase. The results agree with that of the ab initio calculations which have given an XeAu dissociation energy ~100 kJ mol(super -1), plus Mulliken and natural bond orbital populations, MOLDEN plots of valence orbitals, and an energy density distribution.

An atomic force microscopic method was used to study the incubation states of UV laser irradiated polymer samples. This technique allows imaging and detection of whole laser modified area with nanometer resolution.

The photophysical properties, electrochemistry, and electrogenerated chemiluminescence (ECL) of two different ter(9,9-diarylfluorene)s, TDAF is reported. In this process, the formation of excimers was mainly from a reaction of oppositely charged radical ions.

Research has been conducted on silver(I) double salts containing 4-hydroxyquinoline ligand. The authors describe the synthesis of these salts carried out via the hydrothermal method.

The authors review the publications on anions. They discuss the use of fluorogenic and chromogenic reagents for anion sensing.

Research has been conducted on aptamers, small nucleic acid molecules. The authors describe the technology developed for detecting ligand binding by these aptamers which yields solution-phase fluorescence detection.

The reaction between the fluoride ion and chloroethane are analyzed using ab initio molecular dynamics. Some insight into the branching ratio as a function of the temperature is obtained by analyzing impact trajectories.

The suitability ArF laser ablation of micrometer size smoke grains procedure is demonstrated for the destruction of floating solid particles in consequence of very fast heating, oxidation, burning and evaporation. Atomic force microscopic investigations of the sedimented smoke particles proved that the size of the grains significantly decreased by the excimer laser radiation.

Novel methods for incorporation of fluorine into an organic molecule through four member cyclic transition states are presented. The data shows there are minimum of two pathways leading to (CH3)2C-F from propionaldehyde plus CF3 and the fluoride shift product is indistinguishable.

The microstructure, wettability, and thermal stability of self-assembled monolayers (SAMs) on gold generated from semifluorinated alkanethiols are examined by polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) and dynamic contact angle measurements. The analysis by PM-IRRAS revealed that the length of the methylene spacer (Hn) influenced the tilt angle of the fluorocarbon segments in the semifluorinated SAMs.

Two fluoro-substituted versions, F2FIAsH and F4FIAsH, displaying significant improvements in important properties over the original fluorescein derivative FIAsH are presented. The two compounds have formed an excellent FRET pair with a large critical distance and their properties might facilitate improved structural and dynamic studies of proteins in living cells.

The synthesis, structure and performance of new ruthenium-based olefin metathesis catalysts featuring fluorinated N-heterocyclic carbene ligands are described. The increased efficiency is attributed to an unusual fluorine-ruthenium interaction, which reduces the activation energy of rate-limiting phosphine dissociation and catalyst initiation.

The first attempt of using doubly ortholinked quinoxaline/triarylamine 1:1 hybrid as a bifuctional, dipolar electrolumonecent clip is unraveled for bluish green and orange organic light emitting diodes applications. The 1:1 hybrid is potentially bipolar and may act as a central fluorescent of the C5- and C8-appendages.

Two different kinds of strong interactions between alpha,omega-diiodoperfluoroalkane and oxygen that pack in an analogous fashion are presented. Hexamethylphosphoramide (HMPA), a useful electron donor that is involved in two electron donor-acceptor bonds to halogen is reported.