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The synthesis, magnetic, electrochemical, spectroscopic, and physical studies of group of homo- and heterometal complexes is reported. The complexes were generated by using the metal complex [Ni.sup.II][(oximato).sub.3] monoanions as tridentate ligands.

Several studies are conducted to explain the monoanionic [pi]-radical redox state observed in various [alpha]-iminoketones in bis(ligand)metal complexes of nickel and cobalt. These complexes are shown to consist of a high-spin divalent metal center that is strongly coupled to two ligand radicals.

Quantitative studies of cellular systems require experimental techniques that can expose single cells to well-controlled chemical stimuli with high spatiotemporal resolution. Here, we combine microfluidic techniques with the photochemical release of caged signaling molecules to generate tailored stimuli on the length scale of individual cells with subsecond switching times. We exemplify this flexible approach by initiating membrane translocation of fluorescent fusion proteins in chemotactic Dictyostelium discoideum cells.

The preparation and full characterization of the mononuclear neutral complexes [P[t.sup.II]([super t]bpy)(A)] and [P[t.sup.II]([super t]bpy)(B)] (where bpy = 4,4'-di-tert-butylbipyridine, (A) = 3,6-bis(trimethylsilyl)benzene-1,2-(dithiolate(2-) and (B) = 1,2-bis(4-tert-butylphenyl)ethylene-1,2-dithiolate(2-)) is described. The cations are shown to dimerize in C[H.sub.2]C[l.sub.2] solution affording diamagnetic dimers.

An investigation on monolayers of alkyl chains, attached through direct Si-C bonds to Si(111), through phosphonates to GaAs(100) surfaces, or deposited as alkyl-silane monolayers on SiO2 is conducted by ultraviolet and inverse photoemission spectroscopy and X-ray absorption spectroscopy. Exposure to ultraviolet radiation from a He discharge lamp, or to a beam of energetic electrons, leads to significant damage, presumably associated with radiation- or electron-induced H-abstraction leading to carbon-carbon double-bond formation in the alkyl monolayer.

Electron-transfer series are described for three ferric complexes of the pentadentate ligand 4,8,11-trimethyl-1,4,7,11-tetraazacyclotetradecane-1-acetate ([Me.sub.3]cyclam-acetate) with axial chloride, fluoride and azide ligands. The Fe(II), Fe(III) and Fe(IV) species are studied spectroscopically and their UV vis, Mossbauer, EPR, and IR spectra are presented.

A synthesis of a series of mononuclear square-based pyramidal complexes of iron having two 1,2-diaryl-ethylene-1,2-dithiolate ligands in various oxidation levels is conducted. This showed that redox noninnocent ligands exist in at least two oxidation levels, namely, the diamagnetic closed-shell dianionic form and paramagnetic open-shell monoanionic form.

Fourier transform infrared spectroscopy is used to study the different redox intermediates of [NiFe] hydrogenase of Desulfovibrio vulgaris Miyazaki F. It is shown that the Fe carries one carbon monoxide molecule and two [CN.sup.-] molecules as ligands as found for D. gigas and A. vinosum hydrogenase, indicating high degree of similarity among these three enzymes.

Dinickel(II) complexes of the ligands N,N'-di-p-anisylformamidinate (DAniF) and N,N',N'-tripheynlguanidinate (TPG) are synthesized and crystallographically characterized, along with their one-electron oxidized analogues. In both systems, the Ni-Ni distances become shorter by ~0.1 A upon oxidation and it is proposed that this species contains a [Ni.sub.2.sup.6+] core with a single Ni-Ni sigma bond.

Evidence for an interaction of D443 is provided in the N domain of Na(super +), K(super +)-ATPase with a Mg(super 2+) ion. The results are explained by the hypothesis that ATP is bound with two Mg(super 2+) [(Fe(super 2+)] ions, a `catalytic' Mg(super 2+) interacting with D710 via the gamma phosphate and a `structural' Mg(super 2+) interacting with D443 via the alpha and beta phosphates and a water molecule, respectively.

The electronic structure of [Ni(super II)(L(sub N)(super ISQ))2] and of [Pt(super II)-(L(sub O)(super ISQ))2] is calculated by density functional theoretical and correlated ab initio methods. Electronic and resonance spectra is reported, and the electronic structures of all members of this electron-transfer series is established.

The composite nature of the spider dragline silk with respect to its protein constituents is emphasized. It is found that at least two spidroins contribute to the formation of the thread, with Masp 1 seemingly representing the predominant protein while other spidroin-like proteins are likely to be added as a coat layer.

Various procedures for the vacuum deposition of thin histidine films on polycrystalline Au(111) and their characterization with high-resolution synchrotron-radiation-based photoelectron spectroscopy are reported. Water adsorption on pre-prepared film at 100 K results in protonation of histidine molecules and partial formation of hydroxyl anions.

The kinetics of the primary charge separation in the phenolphthalein and malachite green lactone molecules in aprotic solvents is studied using femtosecond pump by probe spectroscopy. The results demonstrate that electron transfer in these molecules occurs faster than the time scale of inertial solvation dynamics.

Ligating properties of four potentially tridentate bisphenol ligands containing [O, X, O] donor atoms (X = S, Se, P, or P=O) toward the vanadium ions in +IV or +V oxidation states are studied. A combination of density functional theory calculations and experimental electron paramagnetic resonance (EPR) investigations indicates a dramatic effect of the heteroatoms on the electronic structure of (X = S, Se, P, or P=O) with consequent reordering of the energy levels.

A high-resolution X-ray photoemission study on three different NTCDA monolayer films on the Ag(111) surface is presented. The study concluded that potential of high-resolution XPS to distinguish between slightly different adsorbate species even in the case of large organic molecules, which is due to their much larger size as compared to the substrate unit cell, occupy very similar adsorption sites independent of the superstructure.

The {Fe(super IV)(Mu-O)(Mu-caboxylato)2Fe(super III)}(super 3+) core represents an important new structural motif in the coordination chemistry of high valent non-heme diiron compounds. Through the successful calculation of the spectroscopic parameters of 4(super ox) and 5(super ox), it is claimed that the calculated structures of these species are realistic and their electronic structure is described qualitatively by the DFT methods.

The physical-chemical analyses of the turbidity relaxations of small unilamellar lipid vesicles of different sizes are studied. It is shown that smaller vesicles can be electro-elongated easily due to the smaller bending rigidity and larger pore fraction.

Research has been conducted on the octahedral complexes with (cis-cyclam)iron(III) moiety and O,N-coordinated o-iminosemiquinonate(1-) pi radical anion. The synthesis of these complexes and their characterization via the use of X-ray crystallography are described.

Research has been conducted on the diamagnetic blue-green palladium and platinum neutral complexes. The preparation and characterization of these complexes have been carried out and the details are reported.

Research shows that the properties of P700 are modulated by the hydrogen bond to the 13(sup)1-keto group of chlorophyll a', suggesting that the polarity of the binding pocket influence P700. Furthermore, the oxidation potential of chlorophyll a' is enhanced if the keto group is hydrogen bonded to Thr A739 residue.

Research has been conducted on the nitrile with acetylene photocycloaddition to 2-pyridine. Results indicate that this [2+2+2]-cycloaddition is a safe and effective method for the 2-pyridine synthesis.

Research has been conducted on the unsaturated amino acid derivatives. The results of the radical cyclization reaction of these derivatives induced by the photoelectron transfer catalysis are described.

Soil samples from an oak forest in County Kerry, Ireland are studied, with and without the addition of the herbicide trifluralin, using high resolution-magic angle spinning nuclear magnetic resonance spectroscopy. Graphs show the spectra of whole soil mixed with two different solvents, and the reactions following herbicide addition.

Results from X-ray crystallography coupled with spectroscopy unambiguously assign the oxidation level of the ligands and metal ion in any given octahedral complexes of o-aminophenolato and o-iminobenzosemiquinonato complexes with transition metal ions V(V), Cr(III), Fe(III), and Co(III).

Research has been conducted on the site-directed mutations replacing D1-His198 and D2-His197 of the Synechocystis PCC 6803 photosystem II reaction center. The construction of a mutation collection in this photosystem has been carried out with and without metal coordinating residues at the homologous histidine positions.

The destabilization of residues 11 through 24 in helix I of amyloid beta protein causes the protein to form a beta sheet structure and aggregate into amyloid fibrils. This process occurs in the brains of patients with Alzheimer's disease.

The homogenous films of Au@SiO(sub 2) particles are deposited on glass as a prototype 3D 'artificial solid' with the help of the LBL method. The films are found to be uniform, colorful and had metallic reflections at low angles of incidence, even at low volume fractions.

The physisorption of a hydrogen molecule on planar and curved graphene clusters was examined through the ab initio molecular orbital theory. The results showed the physisorption energies are majorly increased on curved graphenes.

The location and activity of ruthenium oxide is studied through ab initio total energy pseudopotential calculations. It is found that ruthenium oxide played an active role in photocatalysis.

New techniques are introduced from obtaining single-molecular orientation images and for analyzing the reorientation dynamics of single fluorescent molecules. Methods are also presented to qualify these reorientation dynamics and to identify rotationally mobile molecules.

Electrochemical methods, steady state voltammetry and chronoamperometry are used to measure the temperature dependency of the diffusion coefficient of 1-1'-Ferrocenedimethylanol and 2,2,6,6-tetramethyl-1-piperidinyloxy, TEMPO in aqueous solution and (N-isopropylacrylamide-co-acrylic acid)NIPA-AA thermosensitive gels. The obstruction effect and hydration effect successfully predicted the diffusion coefficient of TEMPO in the NIPA-AA gel.

A combination of polymerization and pyrolysis of a metallo-organic precursor is used to prepare barium titanate BaTiO(sub 3) nanopowders. X-ray absorption near-edge structure (XANES) spectroscopy was applied in the preparation of BaTiO(sub 3) nanopowders.

The NMR characteristics of various types of hydroxyls (OH) are studied through Ab initio molecular calculations. The (super 17)O NMR parameters for hydroxyls in hydrate silicate from experimental vibrational spectra and (super 1)H NMR data are presented.

Research has been conducted on the coiled coils. The thermodynamic activation parameters for the two unrelated coiled coils' folding and unfolding have been identified.

Results reveal that photosystem I complexes exist in monomeric, dimeric, trimeric, and higher level association with similar protein composition. Data from 14000 electron microscopic projections indicate that light-harvesting complex I occur on one side of the complex along with photosystem I subunits.

A study of site-directed mutants has been carried out to look at the influence of the axial ligands on the spectral properties ofthe primary electron donor (P700) of photosystem I. There is good evidence that the unpaired electron in the cation radical and the triplet state of P700 are chiefly localized on the Chl a of the dimer which is axially coordinated by His(B656). Replacement of His(B656) had much greater impact on the physical properties of P700 than did mutation of His(A676).

The relative helix-destabilizing abilities of the 19 common D-amino acids was determined by conformational analysis. An amphipathic model peptide was employed as the host sequence. The analysis of the amphipathic helical model peptide resulted in an L-amino acid environment.

Research has been conducted on the protein stability in vitro. The effect of glycerol addition on the A (sub)2 folding thermodynamics and cavity mutants has been investigated.