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The cooperative enhancement of the anion-pi and pi-pi cooperative interactions between anions and electron deficient aromatics is investigated theoretically. Results of the study indicate that the pi-pi stacking is not enforced by the coordination of the triazines within the particular crystal structure.

Photoelectron-imaging spectroscopy, flowing afterglow-photoelectron spectroscopy and the flowing afterglow-selected ion flow tube technique and electronic structure calculations are used for studying the mechanism of the reaction of the hydroxide ion (H[O.sup.-]) with 1H-1,2,3-triazole. Deprotonation of 1H-1,2,3-triazole at the C5 position has initiated fragmentation of the ring structure to yield a minor product, the ketenimine anion.

The synthesis and characterization of neutral heteroleptic molecular iridium(III) complexes with (2,4-difluoro)phenylpyridine and different pyridine-1,2,4-triazole ligands are described. The studies have shown high external quantum efficiencies and color points better than the standard for blue iridium(III) bis[(4,6-difluorophenyl)pyridinato-N,[C.sup.2]]picolinate.

Catalytic enantioselective desymmetrization of meso-2-substituted glycerols has been developed to secure a novel synthetic route to chiral tertiary alcohols. The transformation has been realized by monobenzoylation using benzoyl chloride and triethylamine in the presence of the imine ligand (25)-Cu[Cl.sub.2] complex in THF at ambient temperature. The desymmetrization turned out to be greatly dependent on acylating reagent, base, solvent, and needless to say, catalyst. Extensive screening of chiral ligands led us to combine bromopyridinecarboxaldehyde 1 and phenyloxazoline amine 12 derived from tert-leucine, the bromo and phenyl substituents of which proved to be indispensable. All of the substrates have been desymmetrized to the corresponding monobenzoates with high enantioselectivity up to 96% enantiomeric excess. The catalytic system allows broad structural diversity of substrates and its synthetic versatility has been demonstrated by an efficient synthetic route to a known key precursor 68 of triazole antifungals. bromopyridinecarboxaldehyde | chiral tertiary alcohols | meso-2-substituted glycerols | phenyloxazoline amine

Hydrothermal chemistry is exploited in the preparation of a series of three-dimensional phases of the Cu/trz/anion family where the anion (X) is [F.sub.-], [Cl.sup.-], [Br.sup.-], [I.sup.-], [OH.sup.-], or [(SO4).sup.2-]. The rich structural chemistry of these phases reflects a number of structural determinants, including the identity of the anionic component and the reaction conditions of stoichiometry, temperature, and pH.

An experiment was conducted to develop an alkyne-azide cycloaddition based route to various C-glycoclusters featuring 1,2,3-triazole rings as linkers and different scaffolds. Each cycloaddition occurred with high regio-selectivity to give exclusively the 1,4-disubstituted triazole ring in very high yield up to an average value of 98%.

In situ sum frequency generation vibrational spectroscopy was performed at varied potentials and polarization combinations on polycrystalline copper, platinum and gold samples in 0.5M HCl[O.sub.4] with 50mM 5-methylbenzotriazole 5-methylBTAH added. For copper surfaces orientation of the molecule on the surface was not affected by potential within the potential window studied and sum frequency generation spectra of 5-methyBTAH on platinum show a change in orientation over the potential range studied.

The aminoxyl radical benzotriazole-N-oxyl (BTNO) is generated by the oxidation of 1-hydroxybenzotriazole (HBT) with a Ce(super IV) salt and characterized by spectrophotometry, EPR, cyclic voltammetry and laser flash photolysis. Rate constants of H-abstraction (k(sub h)) from a number of H-donor substrates by BTNO are determined spectroscopically.

Novel and advantageous methods for the syntheses of several classes of C-sulfonylated products is developed using 1-sulfonylbenzotriazoles. These approaches broaden the range of available sulfone derivatives, which are compounds of major synthetic, biological, and medicinal importance.

A simple and efficient procedure that allows the preparation of aliphatic and (hetero)aromatic alpha-nitro ketones in yields of 39-86% by the C-acylation of a variety of primary nitroalkanes is reported. IN addition, the reaction of N-acylbenzotriazoles with secondary nitroalkanes opens a new way to O-acyl oximes.

The formation, structural, thermal and thermodynamic properties of the first quaternary salts of 4,4'-bi(1,2,4-triazole) or N-4-(1,2,4-triazole)-N-3-(4-methyl-1,2,4-triazole)amine by reaction with nitric or perchloric acid or 5-nitro-tetrazole are described. The melting points, thermal degradation temperatures and the standard heats of formation for compounds with perchlorate as the anion are found to be higher than those of the analogous nitrates, whereas the highest heats of formation are obtained when 5-nitro-tetrazolate is used as the energetic anion.

Energetic salts comprising substituted imidazolium and 1,2,4-triazolium cations and 4,5-dintro imidazolate and 5-nitrotetrazolate anions are synthesized and characterized. It is found that the imidazolate salts are denser but have lower heats of formation than their tetrazolate analogues.

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 regiospecific lithiation-substitutions of 1-[(2EZ)-3-chloroprop-2-enyl]-1H-1,23-benzotriazole and its utilization as beta-acylvinyl anion (-CH=CHCHO) or beta-acylvinyl dianion (-COCH=CH-) equivalents is reported. It has been shown that 3-chloroallylbenzotriazole, in the presence of HMPA, undergoes a regiospecific lithiation-substitution at the CCl terminus to give (oxiranylvinyl)benzotriazoles.

Hartree-Fock ab initio and density functional theory calculations suggest that intra- and intermolecular proton transfer between neutral and protonated triazole tautomers play a vital role in the observed dramatic proton conduction in triazole- base polymer electrolyte membranes (PEM). The species responsible for proton conduction in a 1H (2H)-1,2,3-triazole-containing system are the neutral and pronated triazole tautimers as well as various combination of these species.

Improved peptide-based azidation catalysts that take advantage of the design element are presented. Their application to the synthesis of optically enriched triazoles and triazolines is also done.

A general approach for the synthesis of 1,5-disubstituted-1,2,4-triazole compounds and access a series of new oxamide-derived amidine reagents in excellent yield with minimal purification is described. Both aromatic and aliphatic hydrazines reacted readily with the amidine reagents under very mild reaction conditions to deliver a good yields of desired 1,5-disubstituted-1,2,4-triazole derivatives.

Corrosion experiments and atomistic computer simulations are used for examining three corrosion inhibitors for copper, 3-amino-1,2,4-triazole (ATA), benzotriazole (BTAH) and 1-hydroxybenzotriazole (BTAOH). The trend of corrosion inhibition effectiveness of the three inhibitors of copper in near-neutral chloride solution is found out.

The regioselective cross-coupling reaction of 2,6-dichloronicotinic acid and 2,5-dibromo-1,2,4-triazole derivatives were performed by using the carboxylic acid anion moiety as a tunable directing group. The reaction selectively produced the 2- or 6-substituted nicotinic acids, while only the 5-substituted triazoles were obtained under a variety of conditions.

A pyrrolyl-based triazolophane, which has incorporated CH and NH donor groups, has acted as a receptor for the pyrophosphate anion in chloroform solution. It has shown selectivity for the trianion with NH-anion interactions being more important than CH-anion interactions and in the solid state the receptor binds the pyrophosphate anion in a clip-like slot via NH and CH hydrogen bonds.

The functionalizability and conformational properties of azidoproline (Azp)-containing collagen model peptides (CMPs) are analyzed. The results have shown that (4R)Azp has a similar stabilizing effect on the collagen triple helix as (4R)hydroxyproline and that functionalized CMPs are accessible by ' click' chemistry.

Naphthyl-bridged bis([beta]-cyclodextrin) is prepared by via ' click chemistry' and its self-assembly behavior is analyzed. The results have shown that the coordination of [Hg.sup.2+] with triazole rings in naphthyl-bridged bis([beta]-cyclodextrin) has induced the naphthyl moiety to move from being a self-included complex to the formation of nanoparticles through intermolecular self-aggregation.

Benzotriazol-1-yl-sulfonyl azide, a new crystalline and stable diazotransfer reagent has provided N-([alpha]-azidoacyl)benzotriazoles convenient for N-, O-, C- and S-acylations. The syntheses of amides, azido protected peptides, esters, ketones and thioesters is described along with a wide range of azides and diazo compounds.

The syntheses of two- and three-station mannosyl [c2]daisy chains are described, which are based on a dibenzo-24-crown-8 macrocyclic moiety and an ammonium, a triazolium, and a mono- or disubstituted pyridinium amide station. Variations of the solvent or the temperature have allowed the modification of the population of each co-conformer and thermodynamic data has provided a small free Gibbs energy between the two translational isomers.

The inhibitors of mannosyltransferases are developed by preparing a range of triazole-linked 1,6-oligomannosides up to a hexadecamer by a modular approach centered on the Cu(I)-catalyzed azide-alkyne cycloaddition as key process. Suitable bioassays with dimer, tetramer, hexamer, octamer, decamer, and hexadecamer have displayed variable inhibitor activity against mycobacterial [alpha]-(1,6)-mannosyltransferases, the highest activity being registered with the hexamannoside and octamannoside.

Structure-based modeling methods are used to design a series of disubstituted triazole-linked acridine compounds with selectivity for human telomeric quadruplex DNAs. The obtained compounds are found to exhibit selective inhibitory effects on the proliferation of cancer cell lines compared to a normal cell line and contribute critically towards mediating telomere integrity and cellular immortalization.

An alkaline microfluidic [H.sub.2]/[O.sub.2] fuel cell is used to study the performance of a novel carbon-supported copper complex of 3,5-diamino-1,2,4-triazole (Cu-tri/C) as a cathode material. The absolute Cu-tri/C cathode performance is comparable to that of a Pt/C cathode and the and the performance and durability might be realized by optimizing catalyst and electrode preparation procedures.

Sodium dichloroisocyanurate was reacted with 1-amino-1,2,3-triazole to isolate 1,1' -azobis-1,2,3-triazole. The crystal structure properties and thermal stability and photochromic properties of the obtained triazole isolate is discussed.

The parallel synthesis of seven aza-1,2,3-triazole-3-alanine azapeptides of the g rowth h ormone r eleasing p eptide-6 (GHRP-6) is achieved by a Cu-catalyzed azide-alkyne [3+2] cycloaddition on an aza-propargylglycine residue anchored on Rink amide resin. Circular dichroism spectroscopy in water has shown that azapeptides possessing an aza-1,2,3-triazole-3-alanine residue at the [Trp.sup.4] position of the GHRP-6 sequence has adopted [beta]-turn conformations.

A convenient method is described for preparing 1,2,4-triazolines by using oxazolones and azodicarboxylates. Subsequent treatment of the 1,2,4-triazolines with NaOH has provided efficient access to the corresponding triazoles.

A novel one-pot three- and four-component transformation of D-glucal to furan-based hydroxy triazole glycoconjugates is presented. The reaction involved sequential addition of reagents in the presence of Cu[(OTf).sub.2]-Cu powder as catalysts to form carbohydrate-derived products with high diastereomeric purity.

Photolysis of triazolo[1,5-b]pyridazine isolated in Ar matrix has generated diazomethylpyridazines and diazopentenynes as detected by IR spectroscopy. Three possible mechanisms of ring-contraction in arylnitrenes are identified by ring-opening to dienylnitrenes, concerted ring-contraction and by spiroazirenes.

The reaction of the benzotriazole N-oxyl radical (BTNO) with a series of 4-X-N,N-dimethylanilines (X = CN, C[F.sub.3], C[O.sub.2]C[H.sub.2]C[H.sub.3], C[H.sub.3], O[C.sub.6][H.sub.5], OC[H.sub.3]) is examined in C[H.sub.3]CN. The results are interpreted based on the electron-transfer mechanism from the N,N-dimethylanilines to the BTNO radical followed by deprotonation of the anilinium radical cation (ET-PT mechanism).

Water-soluble arene-cored 'clicked' and non-'clicked' dendrimers terminated by 27, 81 and 243 triethyleneglycol (TEG) tethers are prepared and have formed dendrimer-encapculated gold nanoparticles (DEAuNPs) and dendrimer-stabilized gold nanoparticles (DSAuNPs). The active role of the 'clicked' traizole rings, dendrimer generation, stoichiometry of Au precursor and nature of the reductant and of the solvent are delineated, which has led to DSAuNPs with the G0 dendrimer and smaller DEAuNPs with the G1 and G2 dendrimers.

The natural L-amino acids is used as starting material to generate a small library of chiral, [[beta].sup.3]-substituted homopropargyl alcohols and chiral [[beta].sup.3]-substituted trimethylsilylhomopropargyl azides. The method is extension to the synthesis method to obtain racemic, orthogonally protected 1,4-disubstituted-1,2,3-triazoles from the corresponding [alpha]-substituted propargyl alcohols and [alpha]-substituted trialkylsilylpropargyl azides.

N-Sulfonyl 1,2,3-triazoles have formed rhodium(II) azavinyl carbenes, which has reacted with olefins to produce cyclopropanes with excellent diastereo- and enantioselectivity.