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The synthesis of new cyclam derivatives with diametrically disubstituted pyrene fluorophores is described and their fluoroionophoric properties towards transition metal ions [Cu.sup.2} - and [Hg.sup.2} are studied. It is demonstrated that the diametrically disubstituted pyrene derivatives of cyclam exhibited a selective fluorescence quenching attitude towards [Cu.sup.2}- and [Hg.sup.2} ions in switching-off type responses in aqueous methanol or acetonitrile solution.

Conformational equilibria in formic acid and, adduct of formic acid and hexafluoroacetone, HC[O.sub.2]C[(C[F.sub.3]).sub.2]OH were investigated. Formic acid showed separate signals for the E and Z conformations in solvents containing hydrogen and acceptor with peaks for E and Z conformations found at low temperatures for both formic acid and hexafluoroacetone.

Treatment of the hydrazone of 2H-perfluoro-2-methyl-3-pentanone with trietylamine at increased temperature has yielded a methylenecyclobutene via degradation to acetylene followed by dimerization. The finding suggests that the acidity and the conformational dynamics of the methylenecyclobutene are influenced by buttressing effects in this crowed molecule.

The double bond of 2,3-dimethyl-2-butene (DMB) was very receptive to addition and even at -15degrees C instead of being inhibited to addition of Th+ by its four attached methyl groups. The reaction of Th+ with DMB was followed with cyclic voltammetry and was found to exhibit redox catalysis in which Th was generated.

Syntheses of fluorinated mucin core 2 tri- and tetrasaccharides modified at the C-3 or C-4 position of the pertinent galactose residue is discussed. The results revealed that the activities of only Gal 3-O-sulfotransferases and not sialyltransferases were adversely affected by a C-3 fluoro substituting at the other Gal terminal of mucin core 2.

A significantly improved procedure that provides efficient access to a highly congested 1,8-diacridylnaphthalene fluorosensor is reported. Screening of palladium-catalyzed Negishi, Kumada, Suzuki, Hiyama, and Stille coupling methods showed that the latter affords highly congested 1,8-diarylnapthalenes in superior yields.

A convenient route for the total synthesis of a number of hydrofluorene natural products and their analogues is developed. The protocol is followed to realize the total synthesis of (plusmn)-dichroanal B, (plusmn)-dichroanone, (plusmn)-taiwaniaqunol B and (plismn)-taiwaniaquinones D and H.

A description is provided on the photochemistry of O-chlorooxyalyl and O-fluoroformyl-9-fluorenone oxime. Time-resolved step/scan FTIR spectroscopy investigations on fluoroformyl oxide gave evidence of the formation of fluoroformyl radical FCO(super .) which rapidly adds to the solvent acetonitrile, yielding a fluoroformyl-functionalized iminyl radical.

The carbon 1s ionization energies for all of the carbon atoms in benzene molecules are measured by high-resolution photoelectron spectroscopy. A comparison of the ionization energies and proton affinities gives insight into the effects of fluorine as an electron-withdrawing group and as a pi donor, both in the neutral molecular and in response to an added positive charge.

Photogeneration of C(sub 6)F(sub 5)-C(sub 6)F(sub 4)H from HO-B(C(sub 6)F(sub 5))(sub 3)- and of C(sub 6)H(sub 5)-C(sub 6)F(sub 4)H from C(sub 6)H(sub 5)-B(C(sub 6)F(sub 5))(sub 3)- was studied. The photogeneration of H(sub 2)O.B(C(sub 6)F(sub 5))(sub 3) resulted from irradiation of isoquinolinium hydroxytris(pentafluorophenyl)borate.

The method of ozonolysis of unsaturated organotrifluoroborates to the corresponding carbonyl moieties under standard conditions is described. The technique has given oxo-functionalized organotrifluoroborates that cannot be developed directly via either transmetalation or hydroboration protocols.

The reactivity of intrazeolite photooxidations can be enhanced by a singlet oxygen friendly environment, where the quenching processes are slowed down and the [super 1][O.sub.2] lifetime is increased. The doping of zeolite with fluoroorganic cation has resulted in an increase in the singlet oxygen lifetime at 12 [micro]s.

A new strategy to construct the six-five-six ring system and an application of the methodology to the total synthesis of (plusmn)-4, with a shorter synthetic route and much-improved overall yield is reported. The methodology is applied to the synthesis of (plusmn)-dichroanal B and allowed to achieve a remarkably shorter synthesis, compared to the previously reported total synthesis.

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.

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 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 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.

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.

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 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.

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 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%.

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 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.

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.

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.