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The mechanisms of formation, decomposition, and isomerisation of platinacyclobutane complexes [[PtCl.sub.2]([C.sub.3][H.sub.6])[L.sub.2]] (L is typically pyridine) are discussed on the basis of density functional theory (DFT). The isomerisation and decomposition reactions occur through 5-coordinate intermediates [[PtCl.sub.2]([C.sub.3][H.sub.6])L] that cannot be directly detected. These 5-coordinate complexes are predicted to have distorted square pyramidal structures, but a pinched trigonal bipyramidal (PTBP) stereochemistry is easily accessible. Both [alpha]- and [beta]-elimination from these complexes to give hydride complexes [[PtHCl.sub.2]([C.sub.3][H.sub.5])L] are predicted to have high activation energies. The isomerisation of [[PtCl.sub.2]([C.sub.3][H.sub.6])[L.sub.2]] to the ylide complex [[PtCl.sub.2]{CH(L)[CH.sub.2][CH.sub.3])L] is instead predicted to occur after cleavage of a Pt-C bond to give an intermediate that can be considered as a corner platinated cyclopropane, leading to 1,3-hydrogen transfer without a hydridoplatinum intermediate. The reaction of [[PtCl.sub.2]{CH(L)[CH.sub.2][CH.sub.3]}L] to give the alkene complex [[PtCl.sub.2]([CH.sub.2] = [CHCH.sub.3])L] involves dissociation of the C-L bond followed by a 2,1-hydrogen transfer. The selectivity of related reactions from phenylcyclopropane follows naturally from these mechanisms. Key words: platinum, platinacyclobutane, ylide, alkene, carbene. Nous abordons les mecanismes de formation, de decomposition et d'isomerisation des complexes de platinacyclobutane [[PtCl.sub.2]([C.sub.3][H.sub.6])[L.sub.2]] (ou L est generalement une pyridine) en nous basant sur la theorie de la fonctionnelle de la densite (DFT). Les reactions d'isomerisation et de decomposition procedent par des intermediaires pentacoordonnes [[PtCl.sub.2]([C.sub.3][H.sub.6])L] qui ne peuvent pas etre detectes directement. Ces complexes pentacoordonnes devraient en principe etre de geometrie pyramidale carree deformee, mais une stereochimie bipyramidale trigonale <>serait facilement accessible. Nous avons calcule une energie d'activation elevee pour l'elimination [alpha] et [beta] a partir de ces complexes pour former des complexes d'hydrure [[PtHCl.sub.2]([C.sub.3][H.sub.5])L]. L'isomerisation du complexe [[PtCl.sub.2]([C.sub.3][H.sub.6])[L.sub.2]] en ylure [[PtCl.sub.2]{CH(L)[CH.sub.2][CH.sub.3])L] devrait plutot se produire apres le clivage d'une liaison Pt-C pour former un intermediaire qui peut etre considere comme un cyclopropane a coin de platine, ce qui donne lieu a un transfert d'hydrogene-1,3 sans intermediaire hydridoplatine. La reaction du complexe [[PtCl.sub.2]{CH(L)[CH.sub.2][CH.sub.3]}L] pour donner le complexe d'alcene [[PtCl.sub.2]([CH.sub.2]=[CHCH.sub.3])L] implique la dissociation de la liaison C-L suivie d'un transfert d'hydrogene-2,1. La selectivite de reactions apparentees a partir du phenylcyclopropane decoule naturellement de ces mecanismes. [Traduit par la Redaction] Mots-cles: platine, platinacyclobutane, ylure, alcene, carbine., Introduction Metallacyclobutanes are important intermediates in catalysis, including olefin metathesis and cyclopropanation. (1,2) The first metallacyclobutanes to be isolated were the platinum complexes [{[PtCl.sub.2][([C.sub.3][H.sub.6])}.sub.n] and [[PtCl.sub.2]([C.sub.3][H.sub.6])(py).sub.2]], py = pyridine, first [...]

The 2-adamantyl (2-Ad) group is a particularly challenging alkyl to install on a transition metal, with the only reported 2-Ad complexes of platinum being those of Pt(II). The question of whether 2-Ad complexes with platinum in the oxidation state +IV can be made and whether they are stable is answered here. The Pt(IV) compound trans-[(bpy)[PtMe.sub.2](2-Ad)I] (bpy = 2,2=-bipyridine) was synthesized via oxidative addition of iodomethane to [(COD)PtMe(2-Ad)] (COD = 1,5-cyclooctadiene) in the presence of bpy. Iodide abstraction with silver triflate (triflate anion, [OTf.sup.-] = [CF.sub.3][SO.sub.3.sup.-]) produced trans-[(bpy)[PtMe.sub.2](2-Ad)(OTf)]. Both complexes were unambiguously characterizedby1DNMR ([.sup.1]H,[.sup.13]C) spectroscopy and X-ray crystallography. Both show evidence for the large steric bulk of the 2-Ad group (through the conformation of the complex adopted) and also for its exceptionally pronounced transinfluence (very long bonds to iodide/triflate trans to adamantyl). Both of the new platinum(IV) adamantyl complexes were extremely stable, even to prolonged heating. Key words: platinum(IV), oxidative addition, adamantane, density functional calculations, trans influence. Le groupe 2-adamantyle (2-Ad) est un group alkyle particulierement difficile a lier a un metal de transition; les seuls exemples connus de complexes de 2-Ad avec le platine sont ceux de Pt(II). Nous abordons dans le present article la question a savoir si les complexes de 2-Ade avec le platine a l'etat d'oxydation +IV peuvent etre fabriques et s'ils sont stables. Nous avons synthetise le complexe de Pt(IV) trans-[(bpy)[PtMe.sub.2](2-Ad)I] (bpy = 2,2=-bipyridine) par addition oxydante de l'iodomethane au [(COD)PtMe(2-Ad)] (COD = 1,5-cyclooctadiene) en presence de bpy. L'abstraction de l'atome d'iode par le triflate d'argent (anion triflate, [OTf.sup.-] = [CF.sub.3][SO.sub.3.sup.-]) a produit le trans-[(bpy)[PtMe.sub.2](2-Ad)(OTf)]. Nous avons caracterise sans equivoque les deux complexes par spectroscopie RMN 1D ([.sup.1]H, [.sup.13]C) et radiocristallographie. Les deux methodes revelent un fort encombrement sterique du groupe 2-Ad (par la conformation qu'adopte le complexe) et egalement une influence trans exceptionnellement marquee (liaisons tres longues entre l'iode ou le triflate et le groupe adamantyle). Les deux nouveaux complexes d'adamantylplatine(IV) etaient extremement stables, meme lorsqu'ils etaient exposes a une chaleur prolongee. [Traduit par la Redaction] Mots-cles : platine(IV), addition oxydante, adamantane, calculs de la fonctionnelle de la densite, influence trans., Introduction The chemistry of platinum alkyls has been a testbed for new organometallic chemistry for over 110 years now. When Pope and Peachey synthesized trimethylplatinum(IV) iodide in 1909, it was [...]

The preparation and characterization of cationic, dinuclear complexes of the type trans-[Pt[([PPh.sub.3]).sub.2] (σ-[C.sub.6][H.sub.4]NHMe) -μ-L-Pt[([PPh.sub.3].sub.2] (σ-[C.sub.6][H.sub.4]NHMe)][(OTf).sub.2] (L = 4,4'-bipyridine, 4,7-phenanthroline, 4,4'-dipyrazolylmethane, and 1,1?-diphenyl-4,4'-dipyrazolylmethane; OTf = trifluoromethanesulfonate (triflate)) containing two [C.sup.3]-N-methylbenzamide ligands are described. The key structural feature of the cationic complexes is the presence of two convergent amide groups that may allow for charge-assisted, H-bonding interactions in solution with suitable heteroaromatic guest molecules such as nucleobases. Key words: organoplatinum(II) complex, organometallic host, dinuclear complex, N-methylbenzamide. On decrit la preparation et la caracterisation de complexes cationiques dinucleaires du type trans-[Pt[([PPh.sub.3]).sub.2] (σ-[C.sub.6][H.sub.4]NHMe)-μ-L-Pt[([PPh.sub.3].sub.2] (σ-[C.sub.6][H.sub.4]NHMe)][(OTf).sub.2] [L= 4,4?-bipyridine; 4,7-phenanthroline; 4,4?-dipyrazolylmethane; et 1,1'-diphenyl-4,4'-dipyrazolylmethane; OTf = trifluoromethanesulfonate (triflate)] contenant deux ligands [C.sup.3]-N-methylbenzamide. La caracteristique structurale cle des complexes cationiques est la presence de deux groupes amides convergents qui, en solution, peuvent favoriser des interactions de liaisons hydrogenes assistees par des charges avec des molecules hotes heteroaromatiques appropriees, telles des nucleobases. Mots-cles : complexe organique du platine(II), hote organometallique, complexe dinucleaire, N-methylbenzamide. [Traduit par la Redaction], Introduction There is great interest in the study of synthetic receptors for the selective binding of nucleobases (1, 2), owing to their many important functional roles in biological systems, e.g., [...]

Transparent counter electrodes were prepared on transparent conductive glass (TCG) substrates from a hexachloroplatinic acid ([H.sub.2]Pt[Cl.sub.6]) solution applying the thermal decomposition method in combination with the spin-coating deposition technique. The effect of the precursor concentration and the number of deposited platinum layers on the surface characteristics of the Pt films was examined, and the relation between those surface characteristics and the electrochemical properties of the corresponding modified Pt/TCG electrodes was defined. Four types of counterelectrodes were prepared, differing in the concentration of the [H.sub.2]Pt[Cl.sub.6] solution (0.03M and 0.15M) and in the number of Pt layers (one or two Pt layers); their performance as counterelectrodes was evaluated after their incorporation into dye-sensitized solar cells (DSSCs) employing a solid state redox electrolyte. The obtained results show that solar cells using counterelectrodes prepared from the 0.03M [H.sub.2]Pt[Cl.sub.6] solution and consisting of two Pt lavers (Pt032 electrode) exhibited the best performance characteristics (diffusion coefficient [D.sup.+][I.sub.3.sup.-] = 1.58 x [10.sup.-5] [cm.sup.2] [s.sup.-1], conversion efficiency [eta] = 2.16%, fill factor ff = 62.14%, and short circuit photocurrent [I.sub.sc] = 4.71 mA [cm.sup.-2]). The electrochemical behavior of the modified counterelectrodes is consistent with the surface characteristics of the Pt film that formed on the conductive glass substrate, which seems to be significantly affected by the adopted method and the adjusted experimental parameters (Pt concentration and number of Pt layers). Specifically, this type of electrodes beside their low roughness ([R.sub.q] = 11.5 nm), also presents a high complexity ([D.sub.f] = 2.3). As a result, for this kind of solid state DSSCs, the less rough but the more complex the Pt/TCG electrode surface, the higher the efficiency of the corresponding solar cells. Keywords: dye-sensitized solar cells, platinum counterelectrode, thermal decomposition method, spin-coating technique

The photophysical and third-order nonlinear properties of a cyclometalated platinum(II) 4,6-diphenyl-2,2'-bipyridyl pentynyl complex are examined. The reduced ground-state absorption in the visible spectral range results in a strong and broadband reverse saturable absorption for nanosecond and picosecond laser pulses.

Conductive wires of sub-micrometer width made from platinum-carbonyl clusters are fabricated by using the solution-infilling of microchannels as in microinject molding in capillaries (MIMIC). The wires have displayed ohmic conductivity that has increased, after thermal decomposition of the platinum-carbonyl cluster precursor to Pt.

The synthesis and photophysical properties of anthraquinone-bridged mononuclear and dinuclear platinum(II) complexes are described. The results have shown that the restriction of the Pt-Pt distance flexibility in the rigid structure of this complex has prevented the increase of the Pt-Pt interaction at the excited state.

The synthesis and platinum coordination studies of perfluoroalkyl-substituted 'pincer'-type PCP ligands (PCP = 2,6-[C.sub.6][H.sub.3][(EP[R.sub.2]).sub.2]) are described. The studies have shown that these PCP ligands are electronically analogous to trans acceptor phosphine complexes.

Linkage isomerism is found in a [Pt.sup.II] complex with the model nucleobase 1-methyluracil (1-MeUH). The basic properties of tetrakis- and tris(1-methyluracil) complexes of [Pt.sup.II] are analyzed, concentrating on their acid-base properties and their affinity for additional metal ions.

The synthesis and characterization of emissive complexes involving the Pt(II) metal element displaying blue phosphorescence with fair color chromaticity are described. The blue-emitting Pt(II) complexes are prepared by the treatment of a pyridylpyrazole chelate 3-(trifluoromethyl)-5-(2-pyridyl)pyrazole (fppzH) with [K.sub.2]Pt[Cl.sub.4] in aqueous HCl solution.

Classical molecular dynamics simulations (MD) are used for examining the effect of cisplatin and dinuclear Pt drugs on minor groove flexibility. Findings reveal an imposition of a low strain on the DNA helix by dinuclear Pt compounds and an increase in the energetic barrier associated to minor groove opening.

The synthesis and full characterization of two diiodoboryl complexes formed by the oxidative addition of B[I.sub.3] to [Pt[(P[Cy.sub.3]).sub.2]] (where Cy = cyclohexyl) is described.

The comparative study results of the photophysical and electrochemical properties of a platinum(II) diimine complex bearing the bidentate diacetylide ligand tolan-2,2'-diacetylide (tda) are presented. The results reveal triplet-state mixing between the charge-transfer and tda ligand-localized excited states at 77 K.

The results from spectroscopic studies of [Pt([Me.sub.2]bzimpy)Cl] and [Pt(typ)Cl] ions are presented. The ions exhibit luminescent pillars, when intercalated in ZrP framework at high concentrations.

The synthesis and characterization of a trinuclear cyclometalated Pt(II) 4,6-diphenyl-2,2'-bipyridyl complex with bis(diphenylphosphinomethyl)-phenylphosphine bridging ligand is demonstrated. The complex are found to exhibit broad, positive, and strong transient difference absorption bands from the near-UV to near-IR spectral region.

The accessibility of an unprecedented new class of double-helical molecules in which two [sp.sup.3] carbon chains wrap around an sp carbon chain through a one-step coordination-driven self-assembly process is described. The sp chain has provided a mechanical support and the [sp.sup.3] chain have served as a protecting group, thus enhancing the stabilities of mixed-valent radical cations.

The viability of alkene metathesis in platinum coordination spheres is established along with other reactions for the construction of novel sterically shielding polyynediyl complexes. The results have shown that complexes with termini-spanning diphosphines show [sp.sup.3] chains with both double-helical and non-helical conformations and highly shielded sp chains.

The bis Pt(PBu.sup.t.sub.3) is added to osmium-tin cluster complexes across the Os-Os bond. The structural properties of the new compounds are analyzed by x-ray diffraction studies.

The synthesis and crystal structures of di and trinuclear palladium (Pd) / gold and platinum (Pt) / gold (Au) complexes are studied. These complexes show luminensce at 77K due top metallophilic bonds between Pd/ Pt and Au that give rise to movements of different ligand units of gold.

The preparation of the platinum complexes cis-[PtCl(8-MTT)(PP[h.sub.3])(PTA)] and cis-[Pt[(8-MTT).sub.2](PP[h.sub.3])(PTA) from the precursor cis-[PtC[l.sub.2](PP[h.sub.3])(PTA) (MTTH = 8-(methylthio)theophylline, PTA = 1,3,5-triaza-7-phosphaadamantane) is presented. Antiproliferative activity tests indicate that the presence of one lipophilic PP[h.sub.3] and one hydrophilic PTA makes cis-[PtC[l.sub.2](PP[h.sub.3])(PTA) - cis-[Pt[(8-MTT).sub.2](PP[h.sub.3])(PTA) more active than the analogues bearing two PP[h.sub.3] or two PTA.

Studies were conducted to explore the electronic properties of the cyclometalated (C^N) complexes of iridium and platinum metals with catechol ligand. The complexes were observed to exhibit a reversible reduction of the semiquinone form to the catechol form of the ligand and an irreversible oxidation to the unstable quinone form of the ligand.

A new kinetic mechanism of the NO + N[H.sub.3] reaction is used on Pt{100} in order to simulate the spatiotemporal traveling waves. The Irurzun, Mola and Imbihl (IMI model) has predicted the presence of macroscopic oscillations in the partial pressures of the reactants coexisting with front wave patterns on the surface.

Density functional theory calculations were used to study the morphology of a [Pt.sub.37] nanoparticle supported on carbon with and without hydrogen passivation. It was shown that hydrogen passivation stabilize the truncated structure of [Pt.sub.37] by removing an electronically induced shear instability of Pt(001) facets.

The effect of elemental composition of PtPd bimetallic nanoparticles containing an average of 180 atoms on the kinetics of the electrochemical oxygen reduction reaction (ORR) was investigated. The results show that PtPd bimetallic nanoparticles increase the catalytic activity of the ORR.

The reactions between platinum-bound RCN species and HN-E[R.sub.pi] to specific imines as guanidines are studied to perform and apply nitrile-guanidine coupling to the formation of 1,3-diaza-1,3-dienes. The results have ascertained that it constitutes a novel synthetic approach to a useful class of heterocyclic species like 1,6-dihydro-1,3,5-triazines.

Density functional theory calculations are employed to study and explain the activation mechanisms of a methane molecule on a platinum (Pt) atom and a Pt tetramer, as they both exhibit different properties, like the reaction barrier. The results show that the breaking of the second carbon-hydrogen bond acts as the rate-limiting step of the reaction, as a major energy barrier has to be overcome in this step, which makes it extremely essential.

The effects of an ester group as an alkyne substituent on the reactivity of propargylic enynes, which inhibits the Rautenstrauch process, are analyzed. The steric interactions in the transition structure have provided different hyperconjugation interaction energies that have helped in determining the magnitude of the energy barrier for the rate-limiting H-abstraction step.

First-principles calculations are used to investigate the oxidation properties of model Pt/Hf[O.sub.2] interfaces as a function of oxygen partial pressure. The results have provided an explanation for the differences between measured vacuum and effective work functions for Pt as caused by strong Pt/Hf[O.sub.2] interface reduction.

The synthesis and structural, photophysical, electrochemical and electroluminescent properties of a novel class of trifunctional Pt(II) cyclometalated complexes are described in which the hole-transporting triarylamine, electron-transporting oxadiazole and electroluminescent metal components are integrated into a single molecule. The management of the relative electroluminescent (EL) intensities of the singlet and triplet excitons is shown to be a good tool for making efficient single-dopant white organic light-emitting devices (WOLEDs).

Various steps of preparation process of Pt/[gamma]- [AI.sub.2][O.sub.3] using hydroxyl-terminated generation four (G4OH) PAMAM dendrimers as the templating agents are monitored by extended X-ray adsorption fine structure (EXAFS) spectroscopy. The results indicate that the hydrolysis of two different platinum precursors, namely [H.sub.2]Pt[CI.sub.6] and [K.sub.2]Pt[CI.sub.4] leads to the formation of [Pt[Cl.sub.3][[H.sub.2]O.sub.3]].sup.+ and [Pt[Cl.sub.2][[H.sub.2]O.sub.2]] species respectively.

The first partially oxidized [[Pt(ox)2].sup.n-] complex with a paramagnetic [Cu.sup.II]-bipyridine complex linking to the conducting chain is reported. Magnetoresistance measurements at ambient pressure indicate no interactions of the conduction electrons in the Pt chain with the local spins on [Cu.sup.II] ions and the resistivity decreased with application of hydrostatic pressures of up to 3 GPa.

A study was conducted to understand the kinetics of redox reactions of the [Pt.sup.4](IV) complexes trans-Pt(d,l)(1,2-[(N[H.sub.2]).sub.2][C.sub.6][H.sub.10])[Cl.sub.4] ([Pt.sup.IV][Cl.sub.4](dach)]) and Pt(N[H.sub.2]C[H.sub.2]C[H.sub.2]N[H.sub.2])[Cl.sub.4] (Pt.sup.IV][Cl.sub.4](en)]) with 5'- and 3' -dGMP. The findings reveal that 5'-hydroxo has less rotational barrier than 5'-phosphate, but it is geometrically unfavorable for internal electron transfer.

A study successfully incorporated cyclometalated platinum(II) complex into the (3-aminopropyl)triethoxysilane-modified channels of ordered mesoporous silica SBA-15 that has large pore hexagonal channels. Studies on the [super 1]O2 generation conclusively demonstrates that the olefins in the nano-channels of SBA-15 could be enriched 8 times higher than those in the homogeneous solution as the diffusion quantum yield of singlet oxygen is assumed to be unit.

The synthesis and photophysical study of (C^N)[Pt.sup.II]Q complexes, where C^N is a bidentate cyclometalating ligand and Q is 8-hydroxyquinoline or quinoline-8-thiol are presented. These chromophores absorb intensely in the visible region and emit in the deep-red spectral region from a quinolate-centered triplet intraligand charge-transfer excited state.

The synthesis and characterization of a new class of mixed P,S-mesocyclic ligands and their Pd(II) and Pt(II) complexes is reported. It is demonstrated that the palladium(II) complexes of these new ligands exhibit a significant catalytic activity in the Suzuki-Miyaura cross-coupling reaction.

A reproducible synthesis of platinum nanoparticles (Pt NPs) stabilized with a water-soluble phosphine was developed by ligand exchange with preformed gylcol-stabilized platinum nanoparticles. Complete reduction of oxygen by four electrons is achieved with 4 layers of TPPTP-Pt NPs and a total Pt loading of 5.6 mug/[cm.sup.2].

A series of new luminescent cyclometalated platinum(II) complexes functionalized with various substituted styryl groups on the cyclometallating ligand [Pt(C-ppy-4-styryl-R)(O-(O)CCR'CHCR'C(O))] (ppy-4-styryl-R = E-4(4-(R)styryl-2-phenylpyridine) (3, R'-Me(acac); 4, R'='Bu (dpm); R=H, OMe, NEI 2, NO2)) were synthesized. Results reveal the presence of the styryl -CH=CH-double bond in all the complexes has a direct influence on their emissive properties.

The orientation of the cation and the anion of 1-butyl-3-methylimidazolium dicyanamide at the platinum-liquid interface are reported, using sum frequency generation (SFG) spectroscopy. Results suggest that the imidazolium ring in the cation tends to lie flat at the surface of the electrode at negative potentials but is repelled at positive ones, while the anion is strongly adsorbed at the surface of the platinum at more positive potentials with its [C.sub.2] axis aligned with the surface normal.

A combination of density functional theory calculations and ab initio thermodynamics are used to examine the equilibrium characteristics of a Pt atom, Pt dimer and Pt trimer confined to an idealized surface and in chemical equilibrium with an oxidizing atmosphere. The models have provided a systematic framework for understanding the compositions and energies of redox reactions of discrete metal clusters of interest in supported and gas-phase nanocatalysis.

The stability of the Pt-3d-Pt(111) (3d = Ti, V, Cr, Mn, Fe, Co, or Ni) bimetallic surface structures in the presence of adsorbed oxygen is investigated by means of density functional theory, and the binding energies of oxygen on Pt-3d-Pt(111) and 3d-Pt-Pt(111) are calculated. All the Pt-3d-Pt(111) surfaces are found to have weaker oxygen binding energies than pure Pt(111) whereas all of the 3d-Pt-Pt(111) surfaces are found to have stronger oxygen binding energies than pure Pt(111).

A combined atomic force and scanning electrochemical microscope probe is presented. The probe is electrically insulated except at the very apex of the tip, which has a radius of curvature in the range of 10-15 nm. Steady-state cyclic voltammetry measurements for the reduction of Ru[(N[H.sub.3]).sub.6][Cl.sub.13] and feedback experiments showed a distinct and reproducible response of the electrode. These experimental results agreed with finite element simulations for the corresponding diffusion process. Sequentially topographical and electrochemical studies of Pt lines deposited onto [Si.sub.3][N.sub.4] and spaced 100 nm apart (edge to edge) showed a lateral electrochemical resolution of 10 nm.

Two new platinum complexes that combine a platinum moiety, capable of coordinate covalent bond formation with DNA, to a polyamide capable of recognizing specific DNA sequences were synthesized. These metal complexes show greater binding affinity for the target sequence compared to the mismatch sequence and both complexes can form coordinate covalent bonds with DNA but appear to form dimers in the DNA minor groove, acting as quasi-multinuclear platinum complexes.

The adsorption and thermal chemistry of (S)-(+)-2-methylbutanoic acid [(S)-2MBA] on Pt(111) single-crystal surfaces is characterized by using temperature programmed desorption (TPD) and reflection-adsorption infrared (RAIRS) spectroscopies. Detectable differences in adsorption energetics of (R)- vs (S)-propylene oxide on the (S)-2-methylbutanoate/Pt(111) overlayers were measured but deemed not to be the controlling factor in the enantioselectivity reported in this system.

The surface properties of PtM (M=Co, Ni, Fe) polycrystalline alloys are studied by utilizing Auger electron spectroscopy, low energy ion scattering spectroscopy, and ultravoilet photoemission spectroscopy. The measured valence band density of state spectra clearly shows the differences in electronic structures between Pt-skin and sputtered surfaces.

The controlled decomposition of [Pt.sub.2][(dba).sub.3] (dba = dibenzylideneacetone) dispersed in 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMI.B[F.sub.4]) and hexafluorophosphate (BMI.P[F.sub.6]) ionic liquids in the presence of cyclohexene by molecular hydrogen have produced Pt(0) nanoparticles. The SAXS analysis has shown the formation of a semi-organized ionic liquid layer surrounding the metal particles with an extended molecular length of around 2.8 nm in BMI.B[F.sub.4] and 3.3 nm in BMI.P[F.sub.6].

[Au(NH=C[Me.sub.2])P[Ph.sub.3]]Cl[O.sub.4] and [Ag(NH=C[Me.sub.2])[sub.2]]Cl[O.sub.4] can be used to prepare acetimino complexes of platinum. The species include the first cationic mono- and bis- (acetimino) complexes of Pt(II), the first Pt(IV) complexes with NH=C[R.sub.2] ligands, and the first heteronuclear mu-acetimido complexes of any metals.

A mathematical model that simulates potential oscillations in formic acid oxidation was proposed on the basis of surface-enhanced infrared absorption spectroscopy SEIRAS. The model was constructed within the framework of the dual-path mechanism and a direct path via a reactive intermediate and an indirect path via strongly bonded CO formed by dehydration of formic acid.

An electrochemical scanning tunneling microscopy (STM) is used to study the adlayers of Sb irreversibly adsorbed on Pt(111) at various potentials. The changes in the voltammograms of irreversibly adsorbed Sb on Pt(111) are described in conjunction with the electrochemical scanning tunneling microscopy (EC-STM).

The effect of [M.sup.II] substitution on the magnitude of the negative thermal expansion (NTE) behavior within a series of Prussian Blue analogues, [M.sup.II][Pt.sup.IV]([CN).sub.6] (M = Mn, Fe, Co, Ni, Cu, Zn, Cd), is determined by using variable-temperature powder X-ray diffraction. The results indicate that the magnitude of the NTE behavior is largely influenced by the vibrational flexibility of the metal-cyanide binding interaction, with increased NTE behavior for more flexible frameworks.