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A Huisgen 1,3-dipolar cycloaddition 'click chemistry' was employed to immobilize azido sugars (mannose, lactose, [alpha]-Gal) to fabricate carbohydrate self-assembled monolayers (SAMs) on gold. This fabrication was based on preformed SAM templates incorporated with alkyne terminal groups, which could further anchor the azido sugars to form well-packed, stable, and rigid sugar SAMs. The clicked mannose, lactose, and [alpha]-Gal trisaccharide SAMs were used in the analysis of specific carbohydrate-protein interactions (i.e., mannose--Con A; ECL--lactose, ([alpha]-Gal--anti-Gal). The apparent affinity constant of Con A binding to mannose was (8.7 [+ or -] 2.8) x [10.sup.5] and (3.9 [+ or -] 0.2) x [10.sup.6] [M.sup.-1] measured by QCM and SPR, respectively. The apparent affinity constants of lactose binding with ECL and (x-Gal binding with polyclonal anti-Gal antibody were determined to be (4.6 [+ or -] 2.4) x [10.sup.6] and (6.7 [+ or -] 3.3) x [10.sup.6] [M.sup.-1], respectively by QCM. SPR, QCM, AFM, and electrochemistry studies confirmed that the carbohydrate SAM sensors maintained the specificity to their corresponding lectins and nonspecific adsorption on the clicked carbohydrate surface was negligible. This study showed that the clicked carbohydrate SAMs in concert with nonlabel QCM or SPR offered a potent platform for high-throughput characterization of carbohydrate-protein interactions. Such a combination should complement other methods such as ITC and ELISA in a favorable manner and provide insightful knowledge for the corresponding complex glycobiological processes.

O-type variations on C-H bond dissociation energies were studied.

The first detailed thermodynamic analysis in terms of the driving forces for ach basic step for the nitric oxide (NO)-initiated reaction with 3,6-dibromocarbazolide is presented. It is shown that an electrophilic combination of NO with 3,6-dibromocarbazolide to form the incipient radical anion, followed by electron transfer from the latter to NO, represents the most feasible mechanism. Electron transfer from the electron-rich species to NO may be incorporated when the substrate is a better electron-providing species.

Research was conducted to examine the role of adjacent onium cations and remote substituents on the H-A+ bond equilibrium acidities in dimethyl sulfoxide solution. The study is an extension of previous investigation on ylide thermodynamic stability scale and its implication for the importance of resonance effect on ylide stabilities. Results suggest that part of the stabilization in the phosphonium and sulfonium ylide cases arises from the backbonding stabilization involving the o* and/or 3d orbital participation.

Equilibrium acidities in DMSO for phenylhydrazine, five p-substituted derivatives, 1,2-diphenylhydrazine and 1,1,2-triphenylhydrazine were measured. The bond dissociation enthalpies (BDEs) of their acidic N-H bonds were estimated. The alpha-N-H bonds in CHsub3CONHNHsub2, PhCONHNHsub2, NHsub2NHCOsub2Et and PhSOsub2NHNHsub2 hydrazides were more acidic than the alpha-N-H bonds in corresponding amides, and the BDEs were weaker.

Bond dissociation energies of the acidic C-H bonds in 13 alpha-substituted 9-mehtylanthracenes and 11 10-substituted methylanthracenes. This included equilibium acidity (pKHA), reduction potential Ere(HA), oxidation potential Eox(HA), and oxidation potential of conjugate anions Eox(A-) in dimethyl sulfoxide solution. Equilibrium acidities were linearly correlated with Hammettsigma negative constants. Combinations of equilibrium acidities were used to determine homolytic bond dissociation energies.

The delta G(sub hydride) (R+) data for some stable carbocations and less stable aromatic carbocations derived from substituted toluenes, fluorenes and 9-methylanthracenes are reported. The computation of hydride affinities of organic cations was based on two equations derived from thermochemical cycles. Linear correlations were observed between hydride affinities and solution electron affinities of hydride acceptors. Correlations between delta G(sub hydride)(R+) and pK(sub R+) of corresponding carbinols provide convenient estimates of each other as long as the other is known.

Bond dissociation energies and hydronium ion concentrations at equilibrium of benzylic carbon to hydrogen bonds in dimethyl sulfoxide are presented. Nineteen triphenylmethanes, three dihydroanthracenes and nine xanthenes were used in the experiment. The resonance effect due to the solvation of a substituent induced a conformational alteration to allow for conjugative overlap of the anion and the substituents. The effect of substituents far from the carbanion was found to be negligible.

A thermodynamic study of the cleavage of carbon-sulfur bonds involves the analysis of the enthalpies of reactions between six thiophenoxides and fiveresonance-stabilized carbenium ions. C-S bond cleavage is of interest in the environmentally-critical desulfurization of coal. A battery of calorimetric andvoltammetric tests yield correlated data on the heats of heterolysis and homolysis, redox potentials and heats of entropies of the various processes involved in the reactions. These are presented and discussed in detail.

Alpha-sulfonium groups are radical stabilizing rather than radical destabilizing, as gleaned from theoretical calculations in an examination of the radical substituent effects of the alpha-sulfonium groups. Results showed that the radical-stabilizing effects of the alpha-dialkylsulfonium groups are smaller and with larger steric hindrance than those for the alpha-RS groups. They were also found to be associated with the free lone pair electrons of the sulfur atom in the sulfonium groups. The latter were found to be able to form a two-center three-electron bond with the unpaired electron of the radical.

The first-ever Y-nitric oxide (NO) bond energy scale, where Y is the atom to which NO is attached, is established by direct calorimetric measurements and electrochemical data for three types of N-nitroso compounds. These bond scales establish a technique for determining the dissociation energy of Y-NO bonds in solution and pave the way for developing a complete data set of Y-NO bond energies for a wider range of organic and inorganic compounds.