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The asymmetric imidazolium salt [Ru[(dmbpy).sub.2][(bpip)]([PF.sub.6]).sub.3] (bpip = 1-benzyl-3-isopropyl-1H-imidazo[4,5-f][1,10]phenanthrolinium) was prepared by a four-step synthetic route. The isotopomer labelled with [.sup.13]C at the C2 position of bpip was prepared from 1,10-phenanthroline-5,6-diamine and triethyl orthoformate-(formyl-[.sup.13]C). Deprotonation at low temperatures in acetonitrile using [KO.sup.t]Bu and KHMDS were monitored by NMR to investigate the formation of the free N-heterocyclic carbene. Key words: ruthenium, polypyridyl, [.sup.13]C labelling, N-heterocyclic carbene, photocatalyst. Nous avons prepare le sel d'imidazolium asymetrique, le [Ru[(dmbpy).sub.2][(bpip)]([PF.sub.6]).sub.3] (bpip = 1-benzyl-3-isopropyl-1Himidazo [4,5f][1,10]phenanthrolinium), par une voie de synthese en quatre etapes. L'isotopomere marque au [.sup.13]C a la position C2 du ligand bpip a ete prepare a partir de la 1,10-phenanthroline-5,6-diamine et de l'orthoformiate d'ethyle-(formiate-[.sup.13]C). Nous avons suivi par RMN la deprotonation a basse temperature dans l'acetonitrile effectuee a l'aide du [KO.sup.t]Bu et du KHMDS afin d'etudier la formation du carbene N-heterocyclique libre. [Traduit par la Redaction] Mots-cles : ruthenium, polypyridyl, marquage au [.sup.13]C, carbene N-heterocyclique, photocatalyseur., Introduction A highly investigated method to store solar energy is artificial photosynthesis. (1,2) Water and sunlight are converted into [H.sub.2] and [O.sub.2], or water, sunlight, and [CO.sub.2] are converted into [...]

The ruthenium complexes [Ru[([H.sub.3]CC([CH.sub.2][PPh.sub.2]).sub.3]-[K.sup.3]-P)[([NCCH.sub.3]).sub.3]][(OTf).sub.2] [(1, ([H.sub.3]CC([CH.sub.2][PPh.sub.2]).sub.3] = triphos) and [Ru[(N([CH.sub.2][PPh.sub.2]).sub.3]-[K.sup.3]-P)[([NCCH.sub.3]).sub.3]][(OTf).sub.2] [(2, N([CH.sub.2][PPh.sub.2]).sub.3] = N-triphos) have been evaluated as homogeneous ionic hydrogenation catalysts for the catalytic hydrodeoxygenation of furfuryl alcohol and furfuryl acetate to 1,4-pentanediol and cyclopentanol in aqueous media reaction mixtures. For furfuryl alcohol, only marginal yields of 1,4-pentanediol could be achieved with mass balance deficiencies due to humin formation ranging from 67% to 90%. Attempts to improve the catalytic activity of 2 by enhancing its water solubility by nitrogen protonation and (or) methylation failed. Employing the less self-reactive furfuryl acetate as the substrate substantially diminishes humin formation, yielding up to 43% of 1,4-pentanediol and 19% of cyclopentanol (via Piancatelli rearrangement) with 1 and up to 33% of 1,4-pentanediol and 5% of cyclopentanol with 2. A design of experiments study was used to determine and compare the yield responses of the multiple parallel reaction channels with 1,4-pentanediol, cyclopentanol, and humins as a function of reaction temperature, time, catalyst load, and substrate concentration. This explores the correlations between these parameters and their impact on the reaction outcome and suggests an extremely complex overall reaction cascade of interdependent pathways of both acidand metal-catalyzed steps with some significant differences emerging between the two catalysts. Key words: hydrodeoxygenation, hydrogenation, homogeneous catalysis, sugar derivatives, biomass conversion, diols, design of experiments. Nous avons evalue les complexes de ruthenium [Ru[([H.sub.3]CC([CH.sub.2][PPh.sub.2]).sub.3]-[K.sup.3]-P)[([NCCH.sub.3]).sub.3]][(OTf).sub.2] [(1, ([H.sub.3]CC([CH.sub.2][PPh.sub.2]).sub.3] = triphos) et [Ru[(N([CH.sub.2][PPh.sub.2]).sub.3]-[K.sup.3]-P)[([NCCH.sub.3]).sub.3]][(OTf).sub.2] [(2, N([CH.sub.2][PPh.sub.2]).sub.3] = N-triphos) comme catalyseurs homogenes d'hydrogenation ionique pour effectuer l'hydrodesoxygenation catalytique de l'alcool furfurylique et de l'acetate de furfuryle en 1,4-pentanediol et en cyclopentanol dans des melanges reactionnels en milieu aqueux. Dans le cas de l'alcool furfurylique, le 1,4-pentanediol n'a ete obtenu qu'en faibles rendements et avec un bilan massique deficitaire en raison de la formation d'humines dans des proportions variant de 67 a 90 %. Nous avons tente, sans succes, d'ameliorer l'activite catalytique du complexe 2 en augmentant sa solubilite aqueuse par protonation ou par methylation des atomes d'azote, ou une combinaison de ces deux methodes. En employant l'acetate de furfuryle, qui est moins autoreactif, nous sommes parvenus a diminuer de maniere substantielle la formation d'humines et a produire jusqu'a 43 % de 1,4-pentanediol et 19 % de cyclopentanol (par rearrangement de Piancatelli) avec le catalyseur 1, et jusqu'a 33 % de 1,4-pentanediol et 5 % de cyclopentanol avec le catalyseur 2. Nous avons utilise une approche de type <> pour determiner et comparer les rendements resultant des differentes voies reactionnelles paralleles menant au 1,4-pentanediol, au cyclopentanol et aux humines en fonction de la temperature, du temps de reaction, de la charge catalytique et de la concentration du substrat. Cette approche permet d'explorer les correlations entre ces parametres et les effets de ces derniers sur les produits de la reaction. Le processus global est vraisemblablement le resultat d'une cascade extremement complexe de reactions interdependantes catalysees tant par l'acide que par le metal dont certaines etapes revelent des differences significatives entre les deux catalyseurs. [Traduit par la Redaction] Mots-cles : hydrodesoxygenation, hydrogenation, catalyse homogene, derives de sucres, transformation de la biomasse, diols, plan d'experiences., Introduction Because of their direct applicability in polyester and polyurethane formulations, [alpha],[omega]- and [beta],[gamma]-type diols are some of the most valuable chemicals that can potentially be derived from carbohydrate biomass. [...]

The ruthenium-catalyzed ring-opening reaction of a 3-aza-2-oxabicyclo[2.2.1]hept-5-ene with amines was investigated. In the presence of an amine and a ruthenium catalyst, the N-O bond is cleaved, forming a ring-opened allylic alcohol product. Through a possible ruthenium-catalyzed redox isomerization, the allylic alcohol is transformed into a saturated carbonyl product. This unexpected mode of ruthenium-catalyzed ring-opening reaction of a 3-aza-2-oxabicyclo[2.2.1]hept-5-ene leads to the formation of a cyclopentanone derivative in moderate yields. Key words: ruthenium, amines, heterobicyclic compounds, ring-opening reactions. Nous avons étudié la réaction d'ouverture de cycle par des amines catalysée par le ruthénium que nous avons appliquée à un 3-aza-2-oxabicyclo[2.2.1]hept-5-ène. En présence d'une amine et d'un catalyseur à base de ruthénium, la liaison N-O est clivée pour former un alcool allylique comme produit d'ouverture de cycle. Par une possible isomérisation oxydoréductrice catalysée par le ruthénium, l'alcool allylique est transformé en un produit carbonylé saturé. Ce mode inattendu d'ouverture de cycle catalysée par le ruthénium d'un 3-aza-2-oxabicyclo[2.2.1]hept-5-ène donne lieu à la formation d'un dérivé de la cyclopentanone avec des rendements modérés. [Traduit par la Rédaction] Mots-clés : ruthénium, amines, composés hétérobicycliques, réactions d'ouverture de cycle., Introduction Heterobicyclic alkenes are useful synthetic tools as they can undergo a variety of reactions to create highly substituted ring systems with multiple stereocenters that can be easily further functionalized. [...]

A new (NNN) tridentate ligand was prepared, and its ability to coordinate ruthenium(II) was evaluated. The presence of different functional groups on the ligand allows bi- or tri-coordinated complexes to be obtained depending on complexation conditions. The catalytic activity of both bidentate and tridentate complexes was studied in asymmetric transfer hydrogenation of different aryl ketones, showing a comparable behavior of the two complexes in terms of efficiency and stereoselectivity. Key words: tridentate ligand, asymmetric hydrogen transfer, asymmetric ketones reduction. Nous avons prepare un nouveau ligand tridentate (NNN) et evalue sa capacite de coordination avec le ruthenium(II). La presence des differents groupes fonctionnels sur le ligand a permis d'obtenir un complexe bicoordonne ou tricoordonne selon les conditions de complexation. Nous avons etudie l'activite catalytique de ces complexes bidentate et tridentate a l'egard de l'hydrogenation asymetrique de differentes arylcetones. Le comportement des deux complexes s'est revele comparable en ce qui concerne le rendement et la stereoselectivite. [Traduit par la Redaction] Mots-cles : ligand tridentate, transfert asymetrique d'hydrogene, reduction asymetrique de cetones., Introduction The importance of chirality is widely recognized in fine chemistry, especially in the pharmaceutical, pesticides, and food additives industries. The isolation of a chiral compound from a racemic mixture [...]

Using capillary electrophoresis with inductively coupled plasma mass spectrometry, the transformation of adduct forms of indazolium trans-[tetrachloridobis(1H-indazole)ruthenate(III)] with apo-transferrin and albumin under the effect of active intracellular reducing agents, glutathione and ascorbic acid, and citric acid as a complexant was studied under conditions simulating a cytosolic environment. These adducts of ruthenium with transport proteins are forms in which the anticancer drug exists after intravenous administration. Two modes of interaction of adducts with glutathione, ascorbic acid, and citric acid were studied: in a capillary using a background electrolyte containing a cytosolic active ingredient and upon incubation of the reaction components in the off-line mode, followed by their separation and determination by capillary electrophoresis. Incubation with intracellular components and separation were carried out in a 10 mM phosphate buffer solution (pH 6.0) containing 4 mM NaCl. The effect 1-10 mM of glutathione, 10 mM of ascorbic acid, and 50 mM of citric acid on the adducts was studied. It is shown that under the selected model conditions, new forms of ruthenium do not emerge. Keywords: capillary electrophoresis, mass spectrometric detection, antitumor ruthenium complexes, glutathione, ascorbic acid, citric acid, Platinum(II) complexes used today in cancer chemotherapy have a number of disadvantages, including severe adverse effects and resistance of body to them. Therefore, search for new, targeted antitumor preparations is [...]

Author(s): Mario Fischer-Gdde (corresponding author) [1]; Thorsten Kleine (corresponding author) [1] The excess of highly siderophile elements in the Earths mantle is thought to reflect the addition of primitive meteoritic [...]

Mixed-valence ruthenium (Ru[O.sub.x]) and iridium (Ir[O.sub.x]) oxides and composites on their basis (Ru[O.sub.x]-Ir[O.sub.x] or Ir[O.sub.x]-Ru[O.sub.x]) electrodeposited onto the surface of a glassy carbon electrode exhibit a catalytic activity in the electrooxidation of uric acid, xanthine, and hypoxanthine. The transition from metal oxides to composites of two mixed-valence metal oxides leads to an increase in the catalytic effect of the oxidation of hydroxypurines. The Ir[O.sub.x]-Ru[O.sub.x] composite demonstrated the highest catalytic activity. Procedures for the amperometric detection of hydroxypurines on this composite electrode under the conditions of flow-injection analysis (FIA) and sequential injection analysis are proposed. A linear dependence of an analytical signal on the analyte concentration is observed in the range 1 x [10.sup.-6] to 5 x [10.sup.-3] M for uric acid and xanthine and 5 x [10.sup.-7] to 5 x [10.sup.-3] M for hypoxanthine under FIA conditions and from 5 x [10.sup.-7] to 5 x [10.sup.-3] M for uric acid and xanthine and 5 x [10.sup.-8] to 5 x [10.sup.-3] M for hypoxanthine in sequential injection analysis. Under FIA conditions, the sensitivity, rapidity, and performance of the analysis increase compared to the stationary conditions. The advantages of sequential injection analysis over FIA include a lower consumption of the supporting electrolyte; the absence of pumps and connections; and an increase in sensitivity, reproducibility, and rapidity. Keywords: chemically modified electrodes, mixed-valence ruthenium and iridium oxides, electrooxidation of hydroxypurines, flow injection analysis, sequential injection analysis DOI: 10.1134/S106193481409010X, Hydroxypurines--hypoxanthine (HX), xanthine (X), and uric acid (UA)--are products of the metabolism of purine bases. The control of the concentration of these substances in biological fluids facilitates the diagnostics of [...]

An inorganic film of ruthenium hexachloroplatinate (RuPt[Cl.sub.6]), deposited on the surface of a glassy carbon electrode, exhibits electrocatalytic activity in the oxidation of purine bases, such as adenine and guanine. Appropriate working conditions are found for fabricating a polymer film on the surface of glassy carbon and for recording the maximum electrocatalytic effect for the modified electrode. A method is developed for the selective voltammetric determination of guanine and adenine in their simultaneous presence on an electrode modified by a RuPt[Cl.sub.6] film. A procedure is proposed for the amperometric detection of purine bases with this modified electrode under the conditions of flow-injection analysis. The dependence of the analytical signal on the concentration of guanine and adenine is linear up to 5 x [10.sup.-6] and 5 x [10.sup.-7] M in the stationary mode and to 5 x [10.sup.-7]and 5 x [10.sup.-8] M under flow conditions, respectively. The proposed method was tested in the analysis of calf thymus DNA for the concentrations of guanine and adenine. Keywords: chemically modified electrodes, inorganic polymer films, ruthenium hexachloroplatinate, guanine, adenine, electrocatalysis, electroanalysis, flow-injection analysis DOI: 10.1134/S1061934814080097, Guanine and adenine belong to purine bases and are structural fragments of deoxyribonucleic and ribonucleic acids; they play an important role in preserving genetic information and in protein biosynthesis. The [...]

High-valent iron-oxo species are thought to be intermediates in the catalytic cycles of oxygenases and peroxidases. An attractive route to these iron-oxo intermediates involves laser flash-quench oxidation of ferric hemes, as demonstrated by our work on the ferryl (compound II) and ferryl porphyrin radical cation (compound I) intermediates of horseradish peroxidase. Extension of this work to include cytochrome P450-BM3 (CYP102A1) has required covalent attachment of a [Ru.sup.II] photosensitizer to a nonnative cysteine near the heme ([Ru.sup.II.sub.K97C]-[Fe.sup.III.sub.P450]ll), in order to promote electron transfer from the [Fe.sup.III] porphyrin to photogenerated [Ru.sup.III]. The [RU.sup.II.sub.K97C-] [Fe.sup.III.sub.P450] conjugate was structurally characterized by X-ray crystallography (2.4 [Angstrom] resolution; Ru-Fe distance, 24 [Angstrom]). Flash-quench oxidation of the ferric-aquo heme produces an [Fe.sup.IV]-hydroxide species (compound II) within 2 ms. Difference spectra for three singly oxidized P450-BM3 intermediates were obtained from kinetics modeling of the transient absorption data in combination with generalized singular value decomposition analysis and multiexponential fitting. ruthenium bipyridine | enzyme catalysis doi/< DO>10.1073/pnas.1012381107

An electrospun poly(acrylonitrile-co-acrylic acid) nanofiber mat (PAN-co-[PAA.sub.nfm]) was successfully collected on the surface of a glassy carbon electrode (GCE). Scanning electron microscope (SEM) images showed that the porous electrospun mat was composed of ~160 nm diameter of uniform knitted nanofibers. The cationic luminescence probe, tris(2,2'-bipyridyl)ruthenium(II) complex ([[Ru[(bpy).sub.3]].sup.2+]), was innovatively and first incorporated into the negatively charged PAN-co[PAA.sub.nfm]-modified GCE via electrostatic interaction. Compared with the [[Ru[(bpy).sub.3]].sup.2+] immobilized on normal PAN-co-PAA deposited coating, [[Ru[(bpy).sub.3]].sup.2+]/ PAN-co-[PAA.sub.nfm] exhibited dramatically enhanced electrochemical and electrochemiluminescence (ECL) performances, namely, more than 100 times higher ECL intensity could be feasibly obtained via the electrospinning technique. 10.1021/ac100435z

This work was undertaken to distinguish four pathways for the electrochemical oxidation of acetaminophen as a model organic substrate: (i) direct electron transfer from the substrate to the anode, (iv) reaction of the substrate with HO* at boron-doped diamond anodes, (iii) non-radical (two-electron) oxidation of the substrate at Ti/Ru[O.sub.2] anodes, and (iv) electrochemical hypochlorination if [Cl.sup.-] is present. Pathway (i) was isolated as a slow reaction when boron-doped diamond (BDD) was used as the anode in the range of water stability, whereas in the corresponding reaction with Ti/Ru[O.sub.2] only pathway (iii) could be detected. Pathway (ii) predominated for BDD in the potential range of water oxidation, and was the only mechanism leading to mineralization of the substrate. Comparison between chemical hypochlorination and electrochemical oxidation at Ti/Ru[O.sub.2] in the presence of chloride ion indicated that the latter process principally involves mediated hypochlorination. Oxidation at boron-doped diamond anodes in the presence of chloride was the most complex mechanistically, with competition between hypochlorination and the electrochemical 'advanced oxidation process'; this led to the formation of chlorinated byproducts. The observation of mineralization under these conditions demonstrated cross-over between reaction pathways (ii) and (iV), even though hypochlorination appeared to be the initial pathway for loss of acetaminophen. The presence of chloride ion did not significantly retard mineralization of acetaminophen in the initial stages of oxidation, but significantly increased the energy requirement for complete mineralization. The results are discussed in the context of the use of electrochemical oxidation in waste management. Key words: mineralization, electrochemical hypochlorination, electrochemical advanced oxidation, boron-doped diamond anode, acetaminophen. On a entrepris ce travail dans le but d'eetablir une distinction entre les quatre voies reactionnelles lors de l'oxydation electrochimique de l'acetaminophene utilise comme substrat organique modele : (i) transfert d'electron direct du substrat a l'anode; (ii)reaction du substrat avec le HO* au niveau des anodes de diamant dopees au bore; (iii) oxydation non radicalaire a deux electrons du substrat au niveau des anodes de Ti/Ru[O.sub.2] et (iv) hypochloruration electrochimique si l'anion [Cl.sup.-] est present. La voie reactionnelle (i)a ete detecteee sous la forme de reaction lente quand on utilise du diamant dope; au bore (DDB) comme anode dans la plage de stabilite de l'eau alors que pour la reaction correspondante avec des anodes de Ti/Ru[O.sub.2] on n'a detecte que la voie (iii). La voie (ii) est predominante pour le DDB dans la plage de potentiel d'oxydation de l'eau et c'est le seul meecanisme qui conduit a la mineralisation du substrat. Une comparaison entre l'hypochloruration chimique et l'oxydation electrochimique avec des anodes de Ti/Ru[O.sub.2], en presence d'ion chlorure, indique que le deuxieme processus implique une hypochloruration catalysee. L'oxydation au niveau des anodes de diamant dopees au bore, en presence d'ion chlorure, est la reaction la plus complexe d'un point de vue meecanistique et elle implique une competition entre l'hypochloruration et le processus d'oxydation electrochimique avanceee; ceci conduit a la formation de sous-produits chlores. L'observation d'une mineralisation dans ces conditions a permis de demontrer qu'il se produit un croisement entre les voies reactionnelles (ii)et (iv), meme si l'hypochloruration semblait etre la voie initiale pour la perte de l'acetaminophene. La presence d'ion chlorure ne retarde pas d'une facon significative la mineralisation de l'aceetaminophene dans les etapes initiales de l'oxydation, mais elle augmente considerablement l'eenergie requise pour arriver a une mineralisation complete. On discute des resultats dans le contexte d'une utilisation de l'oxydation electrochimique dans la gestion des dechets. Mots-cles: mineralisation, hypochloruration electrochimique, oxydation electrochimique avanceee, anode de diamant dope au bore, acetaminophene. [Traduit par la Redaction], Introduction Electrochemical oxidation of organic-contaminated wastewaters has received considerable research attention as a possible treatment method. (1-7) Much of this effort has focused on anodes with a high overpotential for [...]

Pyrene-functionalized Ru nanoparticles were synthesized by olefin metathesis reactions of carbene-stabilized Ru nanoparficles with 1-vinylpyrene and 1-allylpyrene (the resulting particles were denoted as Ru=VPy and Ru=APy, respectively) and examined as sensitive chemosensors for the detection of nitroaromatic compounds, such as 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (2,4-DNT), 2,6-dinitrotoluene (2,6-DNT), 1-chloro-nitrobenzene (CNB), and nitrobenzene (NB), by their effective quenching of the nanoparticle fluorescence. It was found that the detection sensitivity increased with increasing nitration of the molecules. Additionally, in comparison to monomeric pyrene derivatives, both Ru=VPy and Ru=APy nanoparticles exhibited markedly enhanced performance in the detection of nitroaromatic explosives, most probably as a result of the enhanced collision frequency between the fluorophores and the quencher molecules. Furthermore, Ru=VPy nanoparticles displayed much higher sensitivity (down to the uanomolar regime for TNT) than Ru=APy in the detection of these nitroaromatic explosives, which was ascribed to the extended intraparticle conjugation that provided efficient pathways for energy/electron transfer and consequently amplified the analyte binding events. 10.1021/ac902394s

Ruthenium-catalyzed preparation of oxindoles from one-pot trimerization of indoles under oxidative conditions and from electrophilic substitution reaction of indoles with isatins or isatin-derived imines under very mild reaction conditions is reported. Key words: ruthenium, oxindoles, isatins, indoles, oxidative conditions. On a realise la preparation d'oxindoles par la reaction de trimerisation monotope d'indoles dans des conditions oxydantes et catalysee par le ruthenium ainsi que par la reaction de substitution electrophile d'indoles avec des isatines ou des imines derivees de l'isatine, dans des conditions reactionnelles tres douces. Mots-cles : ruthenium, oxindoles, isatines, indoles, conditions oxydantes. [Traduit par la Redaction], Introduction Various indole derivatives occur in many pharmacologically and biologically active compounds, (1) and the chemistry of indoles has been and continues to be one of the most active areas [...]

In this work, an electrochemiluminescence (ECL) reagent bis(2,2'-bipyridine)(5,6-epoxy-5,6-dihydro-[1,10]phenanthroline) ruthenium complex (Ru-1) was synthesized, and its electrochemical and ECL properties were characterized. The synthesis of Ru-1 was confirmed by IR spectra, element analysis, and [sup.1]H NMR spectra. For further study, its UV--vis absorption and fluorescence emission spectra were investigated. Ru-1 also exhibited quasi-reversible [Ru.sup.II]/[Ru.sup.III] redox waves in acetonitrile solution. The aqueous ECL behaviors of Ru-1 were also studied in the absence and in the presence of tripropylamine. The complex was fabricated on a [gamma]-(aminopropyl) triethoxysilane (APTES) pretreated indium tin oxide (ITO) substrate via aminolysis reaction between the 5,6-epoxy-5,6-dihydro-[ 1,10]phenanthroline ligand and APTES. The resulting Ru-1 modified ITO substrate exhibited a broad absorption band in the visible region (350-600 nm) and its fluorescence emission spectrum was centered at 622 nm. The Ru-1 modified 1TO electrode showed relative low ECL response. To improve the solid-state ECL response, a gold nanoparticles (GNP)/Ru-1 modified ITO electrode was constructed. The mixing of GNP and Ru-1 could produce the aggregates, which were further immobilized onto a 3-mercaptopropyltrimethoxy-silane (3-MPTMS) pretreated ITO substrate via Au-S interactions to construct the GNP/Ru-1 modified electrode.

An immunoliposome (80 nm in diameter) encapsulating a Ru complex with two aminobutyl moieties was prepared to detect the presence of hemagglutinin molecules, which play an important role in influenza virus infection. The highly sensitive detection was accomplished by electrochemiluminescence (ECL) from the Ru complex adsorbed onto Au electrodes after competitive immunoreactions. This method clarified that the adsorption of the Ru complex onto the electrode was an important factor in obtaining high sensitivity. Optimization of the analytical conditions enabled determination of the hemagglutinin molecules of the influenza virus in the concentration range of 3 x [10.sup.-14] (6 x [10.sup.-19] mol/50 [micro]L sample) to 2 x [10.sup.-12] g/mL. The sensitivity was far superior to that obtained by conventional ELISA as well as to that obtained by biosensors and reported thus far.

The activation energies are measured for phosphine dissociation and ring-closing metathesis for cationized Grubbs first and second-generation catalysts in the gas phase by deconvolution of the energy-resolved collision-induced dissociation cross-sections of electrosprayed ruthenium carbene complexes. The absolute binding energies have agreed well with the latest density functional theory calculations by using a density functional specifically suited for organometallic thermochemistry.

Thio-tethered [Ru.sup.II] terpyridine complexes are synthesized for a voltage-driven molecular switch and are used for exploring the switch-on mechanism of the molecular switches of single metal complexes in the solid-state molecular junction in a vacuum. The single-molecules switch-on mechanism in the solid state has provided guidance in a design that has improved the charge-trapping efficiency of the ligands with different metal substrates.

A divergent strategy for the synthesis of a series of modular and fine-tunable [C.sub.3]-TunePhos-type chiral diphosphine ligands and their applications in Ru-catalyzed asymmetric hydrogenations are explored. The highly enantioselective hydrogenation reactions have provided facile access to optically active amines and [alpha]-hydroxy acid derivatives.

The studies have shown that the nonintercalating bimetallic complex [[[(bpy).sub.2]Ru(tpphz)Ru[(bpy).sub.2]].sup.4+], where bpy is 2,2E-bipyridine, tpphz is tetrapyrido[[3,2-a:2E,3E-c:3EE,2EE-h:2EEE,3EEE-j]phenazine, has behaved like a DNA light-switch complex. This is the first example of a nonintercalating light-switch metal complex, which has shown that light-switch behavior cannot be used exclusively as confirmation of intercalation.

The synthesis of orienticin C, a member of the vancomycin class of antibiotics is reported with the use of an arene-tripeptide complex as a key building block.

The density functional theory (DFT) computation results for a complete catalytic cycle of Ru-catalyzed intramolecular C-H bond amidation of a sulfamate are reported. The findings provide insight into mechanisms and stereoselectivity of metal-catalyzed C-N bond formation reactions.

Mononuclear ruthenium vinyl complexes L-{Ru}-CH[double bond]CH-R is described where the phosphine ligands, the coordination number at the metal and substituent are varied. The vinyl ligands have contributed to the anodic oxidation processes, rendering them a class of truly 'non-innocent' ligands in organometallic ruthenium chemistry.

A ruthenium complex, pentaamine ruthenium [3-(2-phenanthren-9-yl-vinyl)-pyridine] (which we refer to as RuL in the text) generated in situ has been used as a sensitive and selective electrochemical indicator in DNA sensing. The complex incorporates dual functionalities with the Ru center providing a redox probe and the ligand (L) providing a fluorescent tag. The presence of the aromatic groups in the ligand endows the complex with an intercalative character and makes it capable of binding to double-stranded DNA (dsDNA) more efficiently than to single-stranded DNA (ssDNA). Combining spectroscopic and electrochemical techniques, we have elucidated the nature of the interactions. From these data we conclude that the binding mode is fundamentally intercalative. The ligand-based fluorescence allows characterization of the complex formation as well as for melting experiments to be carried out. The metal-based redox center is employed as an electrochemical indicator to detect the hybridization event in a DNA biosensor. The biosensor has been developed by immobilization of a thiolated capture probe sequence from Helicobacter pylori onto gold electrodes. With the use of this approach, complementary target sequences of Helicobacter can be quantified over the range of 106 to 708 pmol with a detection limit of 92 [+ or -] 0.4 pmol and a linear correlation coefficient of 0.995. In addition, this approach allows the detection, without the need for a hybridization suppressor in solution, such as formamide, of not only a single mismatch but also its position in a specific sequence of H. pylori, due to the selective interaction of this bifunctional ruthenium complex with dsDNA

[Ru.sup.II] and [Ru.sup.III] bis([beta]-diketonato) complexes are prepared with protonated and deprotonated pyridine-imidazole ligands. The studies have shown that related ruthenium-imidazolium complexes are dehydrogenated to imidazolate complexes by TEMPO.

The treatment of the 90 degree angular precursor trans-[Ru[Cl.sub.2][(dmso-S).sub.4]] with an equivalent amount of the linear and rigid pyrazine (pyz) linker has produced the molecular triangle [[{trans,cis-Ru[Cl.sub.2][(dmso-S).sub.2]([mu]-pyz)}.sub.3]] instead of the molecular squares. The results have shown that the entropically favored molecular triangles are preferred over the expected molecular squares with metal corner fragments that have favored [N.sub.pyz]-M-[N.sub.pyz] angles narrower than 90 degrees due to the presence of ancillary ligands.

The dinuclear complex [[[C.sub.6][H.sub.2][(C[H.sub.2]E[R.sub.2]).sub.2]-3,5].sub.2.sup.2-] (E = N, P) is prepared by transcyclometalation reaction of the bis-pincer ligand and the Ru(II) precursor followed by a reaction with 2,2':6'2'-terpyridine (tpy). The results have shown a decreased metal-metal electronic interaction by the double-cyclometalated bis-pincer bridge when strong [sigma]-donor N[Me.sub.2] are replaced by weak [sigma]-donor, [pi]-donor P[Ph.sub.2] groups.

A rapid and reproducible method for determining the temperature dependence of luminescence lifetimes has been developed. With the use of this method, a set of standards for the excited-state lifetime oxygen quenching of several ruthenium(II) transition metal complexes was established. With the use of three solvents of different viscosities and two metal complexes with widely different lifetimes, an overlapping range of ca. 100 ns to 6 [micro]s was obtained. The decays are pure single exponentials, which means that they can be used reliably with both phase and pulsed lifetime instruments. For a pure single-exponential decay, a properly operating phase shift instrument will give the same lifetime as a time domain instrument. With the use of a thermal deactivation model and a three-parameter temperature-dependent oxygen quenching constant, the lifetime temperature-dependent data was well fit by a simple six-parameter equation that covers the temperature range of 10-50 [degrees]C and oxygen pressures from 0 to 1 atm of oxygen with excellent precision (ca.

The synthesis and characterization of water-soluble bifunctional amine-tethered [Ru.sup.II] arene complexes which could be used potential anticancer agent is described.

A step-by-step Monte Carlo simulation of single-exponential and multiexponential decays of emission in anisotropic crystals of [Ru[(2,2'-bipyridine).sub.3]][X.sub.2] (X = Cl[O.sub.4.sup.-], P[F.sub.6.sup.-], Sb[F.sub.6.sup.-]) is described.

The synthesis, structural, spectroscopic, and photophysical studies of the ruthenium complex free ligand terpyridine was conducted at room temperature in acetonitrile solution. The properties of complexes with octahedral geometry could be used to synthesize Ru(II)-polyimmine complexes.

The detailed studies about a newly synthesized family of ruthenium(II) bipyridine complexes containing a single carboxylic acid group are presented. The complexes could be used to generate nucleic acid derivatives and bioconjugates incorporating photoactive and redox-active centers.

The studies of two types of lanthanide diruthenium phosphate compounds based on the mixed-valent metal-metal bonded paddlewheel core of [Ru.sub.2](hedp).sub.2.sup.3-] (where hedp = 1-hydroxyethylidenediphosphonate, C[H.sub.3]C(OH)[(P[O.sub.3]).sub.2] is reported. The compounds exhibit a square-grid layer structure and unique PtS-type open-framework structure.

The versatility of the fluorescence polarization immunoassay (FPIA) is increased by using two long-wavelength labels, Nile Blue and a ruthenium(II) chelate. The first label has been used to study the potential of FPIA on a solid surface using dry reagent technology. The aminoglycoside antibiotic amikacin has been used as an analyte model, and the method has been applied to the analysis of serum samples. The second label has been used to show the practical application of FPIA to the determination of macromolecules, using gliadins as an analyte model, which have been determined in gluten-free food. Very low amounts of anti-amikacin antibodies and amikacin-Nile Blue tracer were immobilized onto nitrocellulose membranes, for the development of the amikacin method, and the consumption of reagents is lower than in conventional FPIA. Only the addition of the standard or sample extract at an adequate pH is required at the analysis time. The analyte displaces the tracer from the tracer-antibody immunocomplex, obtaining a decrease in the fluorescence polarization proportional to the analyte concentration. The gliadin-Ru(II) chelate tracer shows a relatively long lifetime, which allows the observation of differences in fluorescence polarization values between the tracer-antibody complex and the tracer alone. The dynamic range of the calibration graphs for both analytes is 0.5-10 [micro]g [mL.sup.-1] and the detection limits are 0.1 and 0.09 [micro]g [mL.sup.-1] for amikacin and gliadins, respectively. The study of the precision gave values of relative standard deviations lower than 5 and 1.5% for the amikacin and gliadin methods, respectively. Amikacin was determined in human serum samples using a previous deproteinization step with acetonitrile, obtaining recovery values in the range 83.4-122.8%. The gliadin method was applied to the analysis of gluten-free food samples by using a previous extraction step. The recovery study gave values between 94.3 and 105.0%.

The synthesis secondary amines, tertiary amines, and silyl enamines in the hydrosilane reduction of secondary amides catalyzed by a triruthenium complex is described.

A statistical condensation reaction of two corresponding phthalonitriles is used to prepare an unsymmetric, peripherally octasubstituted phthalocyanine (Pc). The substituents are combination of dipyrido[3,2-f:2',3'-h] quinoxaline and 3,5-di-tert-butylphenoxy and on photoexcitaion, exhibit efficient intramolecular energy transfer from the Ru(II) chromophore to the MPc moiety.

Intramolecular trapping of an intermediate in the reduction of an imine, 1,4-Bn[super 15]NH(c-[C.sub.6][H.sub.10])[double bond]NBn, by ruthenium hydride has supported an outer sphere mechanism for imine reduction. The reduction of other polar unsaturated substrates such as ketones and aldehydes has proceeded by similar mechanisms.

The analysis explains the mechanism behind the addition of alkene to an oxidized ruthenium thiolate, which then helps in the formation of a bond between carbon and sulfur atoms. In spite of being extremely advantageous, the complexes fail to show any reduction within the solvent.

Methylidene species are used as model complexes for examining the decomposition of a series of ruthenium metathesis catalysts. The decomposition study has provided a basis for design and synthesis of more efficient ruthenium olefin metathesis catalysts.

The activation parameters presented for intramolecular electron-transfer between ruthenium (II) and cobalt (III) complexes for the thermodynamic contribution of the entropy change for the reaction to the entropy of activation are verified.

The description of the electronic effects, due to the noncovalent host-guest interactions between calix [6] arene and a ruthenium dimer, [[[Ru.sub.3] O[(OAc).sub.6](CO)(ppy)].sub.2]-mu-pz where ppy is 4-phenyl pyridine and pz is pyrazine, is given.

The electrochemical and spectroelectrochemical analysis is done to determine the influence of anions on the IVCT processes in the mixed-valence dinuclear ruthenium and osmium complexes. Results showed significant differences in the two techniques in the order and extent of effects induced by a number of inorganic anions.

Electrochemiluminescence (ECL) has been accepted by the analytical chemist as a powerful tool for detection of many inorganic and organic compounds. Ru[(bpy).sub.3.sup.2+] has been the most popular ECL system, and many investigations have been focused on the application based on the enhancement or inhibition of Ru[(bpy).sub.3.sup.2+] ECL system. However, not much attention has been paid to the theoretical investigation of this ECL system, especially to the inhibiting mechanism for the Ru[(bpy).sub.3.sup.2+] ECL system. In the present study, many of the inorganic and organic compounds with electrochemical oxidation activity were found to strongly inhibit Ru[(bpy).sub.3.sup.2+] ECL. To explain these inihibited ECL phenomena, a new 'electrochemical oxidation inhibiting' mechanism has been proposed via the establishment of a corresponding model. The effects of applied potential, uncompensated resistance, and concentration of inhibitor on the inhibited ECL derived from the model have been verified by experiments. The new ECL inhibition mechanism can be commonly used to explain many kinds of inhibited ECL presently observed, and it is envisioned to result in finding of more inhibitors of this type and establishment of new sensitive ECL detection methods for them.