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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

A series of unsymmetrical bi- and tetrathiophenes are synthesized with bipyridine and phosphonic acid functional groups. The variation in oligothiophene length and bipyridine substitution position has allowed comparison of the effect of the variables on electronic properties.

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.

The atomic arrangements inside Ru and Os nanoislands spontaneously deposited on Pt(111) electrode surface are determined with electrochemical scanning tunneling microscopy. The structures of the Ru and Os nanodeposits are addressed in terms of removal and insertion of oxygen ions depending on electrode podtential.

A pure ruthenium hydride complex with N-heterocyclic carbene ligand was efficiently generated from the reaction of a second-generation Grubbs ruthenium catalyst with vinyloxytrimethylsilane and unambiguously characterized. This ruthenium hydride complex showed high catalytic activity for the selective isomerization of terminal olefin and for the cycloisomerization of 1,6-dienes.

The electron-rich cyclopentadienylruthenium complex CpRuCl(PPh3)(sub 2) has turned out to be an efficient catalyst for the cyclopropanation of a wide range of norbornenes and norbornadienes with propargylic carboxylates. An efficient cyclopropanation of cyclobutenes is demonstrated, providing the strained bicyclo[2.1.0(super 1,3)]pentane framework.

The rhodium(III) complex mer,cis-[RhCl3(PPh2py-P,N)(PPh2py-P)] (PPh2py = diphenyl (2-pyridyl)phosphine) is prepared from RhCl3.3H2O and PPh2py and converted to the trans,cis-[RhCl3(PPh2py-P,N)2]PF6 in acetone solution by treatment with Ag(super +) and PF6(super -). The (super 31)P chemical shifts for chelating PPh2py-P,N depend on the Ru-P bond lengths.

Differences in the relative energies of the interconfigurational (IC) transitions for the fully oxidized (+6) states of the osmium systems demonstrate that stereochemical effects lead to fundamental changes in the energy levels of the metal-based dpi orbitals, which are split by spin-orbit coupling and ligand-field asymmetry. An increase in the separation between the IC bands as BL is varied reflects the increase in the degree of electronic coupling through the series of ruthenium and osmium complexes.

Ambipolar charge transport confined to a self-assembled monolayer of a heteroleptic ruthenium complex anchored on the surface of mesoscopic oxides was observed. The bipyridyl ligands of the Ru-complex transport electrons, while the NCS group plays an important role in mediating surface confined hole percolation.

Ambipolar charge transport confined to a self-assembled monolayer of a heteroleptic ruthenium complex anchored on the surface of mesoscopic oxides was observed. The bipyridyl ligands of the Ru-complex transport electrons, while the NCS group plays an important role in mediating surface confined hole percolation.

Individual Ru(4,4'-dicarboxy-2,2'-bipyridine)(sub 2)(NCS)(sub 2) molecules, known as N3, adsorbed on a TiO2 surface are visualized with a scanning tunneling microscope (STM) operated in ultrahigh vacuum. The preferential adsorption of the N3 molecules at the steps is interpreted with the carboxyl groups readily approaching the poorly coordinated Ti atoms at the step edges and this work is the first step for a molecular-scale understanding of well-defined dye-sensitized TiO2 surfaces.

A series of mixed-ligand 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen) rhenium(I) dicarbonyl complexes are synthesized, which includes a new class of the type cis-[Re(CO)(sub 2)(P-P)(N-N)](super +) (where P-P is a chelating diphosphine and N-N is a chelating polypyridine ligand). The properties of these new complexes vary with the net donor ability of the ligands in the coordination sphere and lifetimes and quantum yields of the bipyridine complexes encompass a broad range.

A systematic energy dispersive X-ray reflectometry study of different ruthenium phtalocyanine (RuPc)(sub 2) thin films was performed in order to investigate their reactivity with the oxidizing NO(sub x) gas. A preliminary ex situ analysis, consisting of the comparison between the morphological parameters of different films, before and after the exposure to the gas, was performed.

Thiophene containing hybrids based on the bent conjugated backbone of a rigid ditopic ligand, the dimeric moiety 3,4-dibutyl-2,5-bis{5'-[(3,4-dibutylthien-2-ylethynyl)-2,2'-bipyridin-5-yl]ethynyl}-thiophene (TBTBT) and side decorated with Re(I), Ru(II) and Os(II) metal based units are described. Upon photoexcitation of the heterometallic species, energy transfer takes place via the connecting dimeric ligand.

A planar structure of an anion cluster I(super -).(H(sub 2)O)(sub 6) in a 3D supramolecular complex [Ru(bpy)(sub 3)](sub 2)[I.(H(sub 2)O)(sub 6)Fe(CN)(sub 6).H(sub 2)O] was determined by single crystal X-ray analysis. In the supramolecule, the anion cluster I(super -).(H(sub 2)O)(sub 6), together with the anion [Fe(CN)(sub 6).H(sub 2)O](super 2-) acts as a 3D crystal host, and the [Ru(bpy)(sub 3)](super 2+) cations, as the guest molecule, occupy the vacancies of the 3D host framework.

A series of density functional theory (DFT) and wave function theory methods were used in conjunction with a series of basis sets to investigate the influence of the computational methodology on the relative energies of key intermediates and transition states in potential reaction pathways in ruthenium-silylene-catalyzed hydrosilylation reactions. A variety of DFT methods in a modest basis set and B3YLP calculations in a variety of basis sets calculated the key transition in the Glaser-Tilley (GT) pathway to be energetically favored.

A static electron-transfer quenching mechanism for iodide photooxidation with visible light is demonstrated. The spectroscopic data suggests that the Ru(II)-iodide adducts arise from interactions between iodide and diimine ligand(s) as well as ion pairing.

Development of ruthenacarborane complex [3,3,3-(CO)(sub 3-)closo-3,1,2-RuC(sub 2)B(sub 9)H(sub 11)] is demonstrated by introduction of chelating N-donor ligands such as 2.2'-bipyridyl and the electronic structure of new complexes are examined. Photophysical analysis revealed no substantial luminescent activity, but the complexes are electrochemically active, undergoing sequential one-electron reductions, the second of which likely precipitating a ligand displacement.

The structural and electronic properties of Ru clusters are examined and are crucial to the advancement of technology. Small, nonmetallic ruthenium (Ru(sub n)) clusters are reported to form unusual square and cubic ground-state structures within DFT by treating the exchange-correlation (XC) functional at the level of general-gradient-corrected approximation (GGA).

The analysis and characterization of Ru(II) compounds are described. It is found that these compounds exhibited a single quasi-reversible Ru(super III)/(super II) wave and legand-localized waves corresponding to the sequential reduction of the dimine ligans

The formation and structural characteristics of Ru species applied as a cocatalyst on (Ga(sub 1-x)Zn(sub x))(N(sub 1-x)O(sub x)) were examined by scanning electron microscopy, X-ray photoelectron spectroscopy and X-ray absorption spectroscopy. Calcination was shown to cause the decomposition of initial Ru3(CO)12 on the (Ga(sub 1-x)Zn(sub x))(N(sub 1-x)O(sub x)) surface to form Ru(IV) species.

The usefulness of intervalence-resonant Raman spectroscopy in exploring the localized-to-delocalized transition in mixed-valence chemistry is demonstrated. The results presented give evidence for vibronic coupling of totally symmetric bridging vibrations of pyrazine to the 'intervalence' charge transfer that confirms a near-delocalized description for the mixed-valence cluster dimer.

Photocurrent measurements are made on nanocrystalline TiO2 surfaces derivatized by adsorption of a catalyst precursor or chromophore, and on surfaces containing both complexes. The experiments are carried out with the I(sub 3)(super -)/I(super -) or quinone/hydroquinone (Q/H2Q) relays in propylene carbonate, propylene carbonate-water mixtures, and acetonitrile-water mixtures.

Synthesis of two neutral diruthenium complexes and one anionic diruthenium complex, Ru2(dpf)4(NO), Ru(dpf)4(NO)2, and [Ru(dpf)4(NO)](super -), where dpf is diphenylformamidinate anion, was conducted and characterized as to their electrochemical and spectroscopic properties. Results reveals the presence of a strong interaction between No and Co across the metal-metal bond.

Surface plasmon absorption (color) of Au nanoparticles highly depends on its size, shape, and surrounding surface environment, providing a great opportunity for the development of Au nanoparticles as a probe for chemical and biochemical sensing and as a building block for nano-optical devices.

A combined experimental and computational study of polynuclear [Ru(sub n)(TPPZ)(subn+1)](super(2n+) complexes of interest in the field of photoactive polymers are reported. The complexes with n = 1,2,3 and n>5 are synthesized and spectroscopically characterized.

Investigations on the ruthenium porphyrin-catalyzed intramolecular amidation of sulfamate esters and of the first intramolecular aziridation of unsaturated sulfonamides are reported. Bicyclic aziridines up to 87% yield with 100% substrate conversion and high turnover were produced.

The dynamics of metal-to-ligand charge transfer (MLCT) in a cis-bis(4'4-dicarboxy-2,2'-bipyridine)-bis(isothiocyanato)ruthenium(II) dye (N3) are compared for the free dye in solution and the dye absorbed on the surface of the TiO2 nanoparticles from resonance Raman spectroscopy. The 544-nm MLCT absorption band of N3 absorbed on TiO2 is slightly blue-shifted from that of the free N3, indicating a weak electronic coupling between N3 and TiO2.

Single molecules detected through the phosphorescence emission of their triplet states, and the emission of the triplet state of single molecules of PtOBCP and Ru(dpp)3Cl(sub 2) are reported. Each molecule was found to have its own characteristic quenching rate by oxygen, and the distribution of the rates was measured for Ru(dpp)3Cl(sub 2) on a quartz surface.

Threading behavior of dimeric ruthenium complex was studied. Differences were found in the SDS-induced dissociation kinetics.

The heterolytic cleavage of H2 is regarded as a key step in the metalloenzymatic reactions of hydrogenases, the actives sites of which consist of the sulfur-bridged Fe/Fe and Fe/Ni dinuclear centers. Based on the experimental results, the mechanism of the heterocyclic H2 activation and the reverse H2 evolution reactions are discussed.

The calculations on the geometries and energy barriers for carbon monoxide decomposition on flat ruthenium surfaces through an indirect route are given. The procedures used in the study are explained.

Study was conducted to prepare Ru(II) coordination compounds with long-lived strongly oxidizing, excited states that can be anchored to semiconductor surfaces for applications in dye-sensitized photogalvanic cells. The products of reductive electron-transfer reactions at sensitized semiconductor interfaces are studied.

The black-dye/TiO2 system by electronic absorption and vibrational spectrocopies are characterized. The FT-IR spectroscopic data reveal that black-dye molecules are bound to the Tio2 surface via a bidentate binuclear coordination.

The atomic structure of RuO2.xH2O as a function of water content from x=0.84 to 0.002 using X-ray diffraction and atomic pair density function is studied. The result reveals that RuO2.xH2O is a composite of anhydrous rutile-like RuO2 nanocrystals dispersed by boundaries of structural water associated with Ru-O.

The atomic structure of RuO2.xH2O as a function of water content from x=0.84 to 0.002 using X-ray diffraction and atomic pair density function is studied. The result reveals that RuO2.xH2O is a composite of anhydrous rutile-like RuO2 nanocrystals dispersed by boundaries of structural water associated with Ru-O.

The IR spectroscopy is use to investigate the interactions of nitric oxide gas with thin layers of Fe(super ll)(TPP) and Ru(super ll)(TPP), obtained by sublimation onto low-temperature substrate (77 K). It was found that purified nitrogen oxide does not react with Fe(TPP)(NO) to give Fe(TPP)(NO)(NO2), however, this interaction led only to the formation of unstable trans-dinitrosyl complex Fe(TPP)-(NO)2.

An ultrafast spectroscopic investigation of the photoinduced energy migration dynamics that take place within a supramolecular assembly consisting of 20 Ru(II) and/or Os(II) polypyridyl coordination complexes linked together through a polystyrene backbone is described. The results demonstrate that the Ru(II) derivatized polymers act as efficient antennas for collecting visible light and transferring its energy along the polymer backbone.

The various oxygen species on the RuO2(110) surface is characterized and compared with those on Ru(0001) in terms of the local absorption geometry, vibrational modes, electronic properties, and kinetics. By the application of new techniques of LEED, high resolution electron loss spectroscopy and density functional theory calculations, new data are collected.

UV-vis, FTIR spectroscopies and cyclic voltammetry were used for characterizing and determining the features of the monolayers at air-liquid interface of the Langmuir-Blodgett films containing a arachidic acid (AA) and [Ru(L)(totpy)(OH2)](ClO4)(sub 2) (L=Ph2AsCH2CH2AsPh2; 4-totpy = 4'-(4-totyl-2,2':6',2'-terpyridine)) complex. The results indicated that the matrix, which was thought as solid as arachidic acid at low pH, with low possibility of dissolving solutes was able to render a fluid behavior even at low areas in terms of the acid depending on the co-spreading material.

A study of photosensitized electron-transfer reactions between trist(2,2'-bispyridine)ruthenium(II) (Ru(bpy)(sub3) (super 2+) and bipyridinium ions are studied. Zeolites not only provide for novel spatial arrangements of molecules but also provide ways to introduce steric constraints and a novel solvation environment.

The reaction of the dihydride [Ru(super II)(H)(sub 2)(CO)(PPh3)(sub 3)] with excess azo-2,2'-bipyridine (abp) in boiling dry benzene has afforded the diradical bischelate [Ru(super II)(abp(super .-))(sub 2)(CO)(PPH3)] and the hydridic monochelate monoradical [Ru(super II)(abp(super .-))(H)(CO)(PPH3)(sub 2)]. The diradical bischelate displays strong metal-mediated antiferromagnetism, and upon oxidation to the monoradical the unpaired electron with approximately 40 percent azo pi(super star)-character gets localized in one of the chelate rings.

Dibromomalonic acid (Br2MA) oxidizes the photo excited state of the Ru(bpy)(sub 3)(super 2+) complex producing Br2.the first of these reactions play an important part in the mechanism of photoinhibition of the Belousov-Zhabotinsky reaction.

Visible light-driven intermolecular electron transfer observed from a reduced species Ru[(bpy).sub.3.sup.+] to bioinspired [2Fe2S] model complexes of the iron-only hydrogenase active site is reported. The results indicate that Ru[(bpy).sub.3.sup.+] could act as a photoactive functional model of the [4Fe4S] cluster playing the role of an electron-transfer relay.

Nitrogen-incorporated SAPO-11 molecular sieves are synthesized by a secondary synthesis technique at low nitridation temperature (400 degree C) with a starting material of SAPO-11 zeolite doped with two wt % Ru. It was found that nitrogen-containing species had incorporated into framework of SAPO-11 zeolite, in which some N atoms directly bonded to Al and P atoms and formed AlN4, AlN2O2, and PN4 groups.