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A study shows that reduction of the radical cation [NSSNC-CNSNS][AsF6] with ferrocene leads to the novel biradical (super .)NSNSC-CNSSN(super .) exhibiting an exceptional pi*-pi* dimer between isomeric 1,2,3,5- and 1,3,2,4-dithiadiazolyl rings. It is shown that paramagnetism of the title biradical can be enhanced upon grinding by the magnetic susceptibility measurements.

ZnO thin films and [([Bu.sub.4]N).sub.2](Ru)[(dcbpyH).sub.2][(NCS).sub.2] (N719) sensitized ZnO thin films are grown on fluorine-doped tin oxide (FTO) conducting glass substrates by using laser molecular beam epitaxy and the transition process of photogenerated charges and the interaction between ZnO and N179. The interaction has enhanced the photogenerated charge separation and the photovoltaic response of the ZnO film, but has weakened its radiative recombination, implying strong energy and charge transfer occurring between N179 and ZnO.

Primary-secondary diamine catalysts are used for catalyzing the asymmetric Robinson annulation. This has helped in the preparation of multiple substituted fluorinated chiral cyclohexenones with two contiguous steregogenic centers, one of which is a fluorinated quaternary chiral center.

The bisstannylation has produced the corresponding bisstannylated cis-adducts by treating various fluorinated internal alkynes with hexabutylditin under the affect of Pd[(t-BuNC).sub.2][Cl.sub.2] in THF at room temperature. These adducts are subjected to the Stille cross-coupling reaction to give the corresponding tetrasubstituted fluorine-containing alkenes with defined stereochemistry.

A practical and efficient synthesis of bradykinin [B.sub.1] antagonist is described, where a convergent strategy is used that has involved synthesis of three fragments. The major factor for the success of the synthesis is the development of a fluorodenitration step to install the fluorine in pyridine and a catalytic enantioselective hydrogenation of N-acyl enamide to set the stereochemistry.

The synthesis of a nucleoside that could be used in Bronsted experiments to assess the transition state of ribosome catalyzed peptide bond formation is described. The nucleoside 3'-amino-3'-deoxy-3'-[(3'R)-3-fluoro-L-phenyl-alanyl]-[N.sup.6], [N.sup.6]-dimethyladenosine prepared from (1R, 2R)-2-amino-1-phenylpropane-1,3-diol is active in peptide bond formation on the ribosome and is useful probe for Bronsted analysis experiments on the ribosome.

The B3LYP/6-311G**+ level of theory was utilized to study the degenerate ring inversion in bicyclo[1.1.0]butane and eight of its fluorinated derivatives. The results showed that fluorine substitution significantly lowers the inversion barrier in bicyclo[1.1.0]butane.

The synthesis of polyfunctionalized benzo[d]sultams containing an [alpha]-amino acid unit from the corresponding open chain (pentafluorobenzene)sulfonamides is reported. The cyclization step in the reaction carried out via solid-liquid phase transfer catalysis (SL-PTC) and homogeneous protocols proceeds through the intramolecular nucleophilic displacement of an aromatic fluorine atom.

A novel class of difluorinated cyclooctyne (DIFO) reagents is described for copper-free click chemistry that is more synthetically tractable. The new analogues have maintained the same elevated rates of [3+2] cycloaddition as the parent compound and are used for imaging glycans on live cells and these second-generation DIFO reagents have expanded the use of copper-free click chemistry.

The carbon-fluorine bond formation from two high-valent aryl palladium fluoride complexes is demonstrated. The data obtained on reductive elimination provide insight into carbon-fluorine bond formation from arylpalladium complexes.

The [S.sub.1]-[S.sub.0] limiting anisotropy of rhodamine 101 is accurately determined by using time-resolved and steady-state fluorescence measurements. The limiting anisotropy of rhodamine 101 is equal to the theoretical one-photon fundamental anisotropy and it can be used as a standard for fluorescence polarization measurements.

Density functional theory (DFT) cubic response theory and the polarizable continuum model are used for studying the solvent-induced three-photon absorption cross section of a highly conjugated fluorene derivative. It is shown that the simplified model performs poorly for the three-photon absorption properties of the symmetric charge-transfer molecule and the dielectric medium has increased the three-photon absorption cross section.

Fluorene derivatives, having substituted benzyl groups bonded to position 9, are examined by variable temperature NMR spectroscopy. Stereodynamic processes involving restricted rotation about the fluorenyl-C[H.sub.2] and aryl-C[H.sub.2] bonds have led to conformers and enantiomeric forms.

The synthesis and characterization of 2,3,5,6-tetrafluorophenylnitren-4-yl in argon at 4 K via the photolysis of 2,3,5,6-tetrafluoro-4-iodo-phenyl azide is presented. The quartet ground state of 2,3,5,6-tetrafluorophenylnitren-4-yl is found to show high-spin quartet state but no low-spin doublet state.

The development of new method to synthesize perfluoro[2.2]paracyclophane from reaction of 1,4-bis(chlorodifluoromethyl)-2,3,5,6-tetrafluorobenzene with Zn, heated in acetonitrile at 100 degree Celsius is reported. The study demonstrates the application of Perfluoro[2.2]paracyclophane for deposition experiments to determine the impact of perfluorination on properties of the respective parylene polymer.

A study was conducted to examine the aroylation of fluorobenzenes using imidazolium salts with various substituents as N-heterocyclic carbene (NHC) precursors to improve the yields and reduce catalyst loading. The NHC derived from 1,3,4,5-tetramethylimidazolium iodide is found to an excellent catalyst for the nucleophilic aroylation, which could reduce catalyst loading, by 1 mol % without significant drop in the product yield.

Various methods for the preparation of sulfonated, water-soluble 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) systems is described. The observations from spectral analysis showed the materials to be highly fluorescent probes in aqueous environments.

The time-resolved Raman spectroscopy is used to study the hydrogen-abstraction reaction of decafluorobenzophenone (DFBP) from 2-propanol in temperatures ranging from room to supercritical temperature (520 K) at 31 MPa. The vibrational frequencies of the C=C stretching modes which decrease with increasing temperature reflect the decrease in the repulsive effect due to the decrease of the packing fraction.

The design and synthesis of two novel fluorine-boron cored fluorescent complexes are described. These complexes have exhibited well-ordered molecular packing, intense fluorescence and low LUMO levels, which are useful as electron-transport materials in electroluminescent (EL) devices.

A method is described for predicting the resonance energy transfer in condensed phases based on a combination of computer simulations of phase morphologies and of a distributed monopole model for the radiationless transfer. This scheme is demonstrated for a condensed glass phase formed by perylene monoimide end-capped 9,9-(di n,n)octylfluorene trimers, where a coarse-grained Monte Carlo simulation of the molecular organization and master equation approach modeling the energy diffusion process is coupled.

The interfacial interplay and the properties of the mixed bilayer films, which have poly(9-vinylcarbazole) and poly(9,9-dioctylfluorene-2,7-diyl), fabricated by sequential spin-coating process are examined. A schematic model is developed, the polymer light-emitting diodes (PLEDs) are fabricated based on these mixed bilayers and blue emissions are obtained with increased performances under optimized conditions.

The solid-state NMR studies of [([C.sub.2.5]F).sub.n] fluorine-graphite intercalation compounds (GIC) which converts to covalent graphite fluoride during a post-treatment in pure fluorine gas is reported. The results provide insight into hyperconjugation of the C-F bonds with neighboring unfluorinated carbon atoms.

Electronic spectroscopy is used for studying the polycyclic hydrocarbons containing a five-member ring and their van der Waals complexes with argon and oxygen are studied with a molecular beam superfluid helium nanodroplet spectrometer. The van der Waals complexes of fluoranthene have displayed more peaks.

Several spectroscopic studies are conducted to explain the interplay between the on-chain keto defect and the interchain interaction its impact on the green and blue emission of polyflourene (PF). The analysis reveals that the interaction leads to severe color degradation, which then minimizes the green emission.

A general and efficient enzymatic approach is described for producing fluorinated mechanistic probes for sialidases and sialyltransferases. Enzymatically produced 3-fluoro-sialosides are found to be potential inhibitors and mechanistic probes for sialidases.

The three-dimensional [19.sup.F]-[1.sup.H] heteronuclear TOCSY is widely used for filtering and editing in the NMR experiments of various fluorochemicals encountered in drug delivery. The addition of a third dimension chemical shift helps in the simultaneous characterization of the compounds.

A new class of highly emissive fluorescent dyes based on the diphenylboron N,N'-chelate complexes of 2-(pyrazolyl)anilines are prepared and characterized by multiple methods. The results have shown that chelation to the Lewis acidic diphenylboron moiety has brought the pyrazolyl and aniline rings closer to coplanarity than found in the free ligand.

The synthesis and the properties of the donor-acceptor containing polyfluorene derivative and its carbon nanotube composites prepared by Suzuki polymerization are described. These substrates are found to exhibit highly bistable electrical switching and a write-once read-many-times memory effect.

The syntheses, Raman spectra, and crystal structures of four new metal(II) hexafluorophosphates(V) containing Xe[F.sub.2] as ligands are described. It presents that Raman spectrum of the bulky belongs to the same compound that was structurally characterized.

The Suzuki-Miyaura coupling reaction that can be effectively used for the chain-growth polymerization to produce compounds like polyfluorene from an externally added initiator unit is described. The polycondensation is found to proceed in a chain-growth manner from the initiator unit derived from the catalyst.

The synthesis of a small molecule 4,7-di-2-thienyl-2,1,3-benzothiadiazole (DBT) dye is carried out which is further blended into blue-emitting polyfluorene as a host. The role of intra-and interpolymer chain interaction and energy transfer in the polymer light emitting devices are discussed.

A study reports that fluorinated phenoxide could be used to form stable, soluble compounds of Eu(II) and Eu(III) as well as a heterovalent dimer. Dative Ln-F interactions were noted with Eu(II) ions while Eu(III) ions were observed to adopt terminal phenoxide ligations and since phenoxides are soluble in apolar media, they are potentially useful as capping reagents in lanthanide cluster chemistry.

The interaction between the anionic poly{1,4-phenylene-[9,9-bis(4-phenoxy-butylsulfonate)]fluorene-2,7-diyl}copolymer (PBS-PFP) and cationic gemini surfactants are studied in aqueous solution. The surface tension experiments show that presence of the polymer does not affect the surfactant critical micelle concentration (CMC), while small-angle neutron scattering (SANS) studies have shown the formation of spherical aggregates and has suggested a slight increase in radius, compatible with PBS-PFP/micelle interactions.

A study was conducted to synthesize and characterize subphthalocyanine (SubPc)-fused dimers and trimers bearing fluorine, iodine, and thioether peripheral substituents. Absorption spectroscopy and electrochemical studies reveal that the substituents have a strong effect on the electronic properties of the macrocycles and good communication was shown between the subphthalocyaninic moieties within the oligomeric structures.

A simple and efficient synthesis of hitherto unknown chlolestanofluorene and its derivatives from the readily available cholestanone as the starting material is described. An appropriately substituted fluorene derivative (R = OMe) forms a highly colored (chiral) cation-radical that could be isolated as robust hexachloroantimonate salt.

A stereoselective synthesis of an all-syn four vicinal fluorine motif as a single enantiomer is described in a format, which will allow its direct incorporation into larger molecular architectures. Such a motif has potential for a variety of applications in the design of novel materials such as liquid crystals and self-assembling monolayers or in the synthesis of elaborate deoxyfluoro sugar analogues and broadens the available range of functionalized alkanes.

The reaction of Al[Cl.sub.3].3Py with [Me.sub.3]SiF aimed at the synthesis of [[Al[F.sub.2][(Py).sub.4]].sup.+][Cl.sup.-] and a room-temperature stable complex with a monomer molecular structure in the solid state is reported. The [super 27]Al MAS NMR spectrum of Al[F.sub.2]Cl.4Py has revealed an unexpected complexity due to the very large quadrupolar coupling constants (QCC) and can be resolved only at spinning rates above 25 kHz.

A study demonstrates that the magnitude of the attractive interactions of [C.sub.6][F.sub.6]-[C.sub.6][H.sub.5]X dimers depends on the closeness of contact between the arenes and on the donor ability of the benzene substituent (X). The optimized minimum configurations of [C.sub.6][F.sub.6]-[C.sub.6][H.sub.5]X dimers have a parallel displacement rather than a sandwich configuration indicating that more complex interactions are involved than simple Coulombic attraction.

The effect of fluorine substitution at aziridine positions other than nitrogen is examined. The results are rationalized by the energy contributions of strain energy releases, stabilization of the leaving group and the relative electrostatic energies of the heterocycles in the transition states and the more reactive fluoroaziridines have undergone nucleophilic attack at rates comparable to those of N-acetylaziridine.