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We demonstrate here the synthesis of a novel class of metallo-supramolecular polymers with shackled structure, via the coordination of cyclic di(bisterpyridine-triphenyl ether ester) ligands with ruthenium-(II) ions. The constraint from the ring topology via the shackling of ligands provides novel properties to these metallo-supramolecular polymers, including the formation of dendritic crystals, red-shift of absorption bands in the UV--vis spectra from interchain charge-transfer transitions, and a typical flash-type memory behavior. [ABSTRACT FROM AUTHOR]

We describe the development of a mechanochemical approach for Ru-catalyzed olefin metathesis, including cross-metathesis and ring-closing metathesis. The method uses commercially available catalysts to achieve high-yielding, rapid, room-temperature metathesis of solid or liquid olefins on a multigram scale using either no or only a catalytic amount of a liquid. [ABSTRACT FROM AUTHOR]

Photophysics of the MLCT excited-state of [Ru(bpy)(tpy)(OH2)]2+ (1) and [Ru(bpy)(tpy)(OD2)]2+ (2) (bpy = 2,2'-bipyridine and tpy = 2,2':6',2'-terpyridine) have been investigated in room-temperature H2O and D2O using ultrafast transient pump-probe spectroscopy. An inverse isotope effect is observed in the ground-state recovery for the two complexes. These data indicate control of excited-state lifetime via a pre-equilibrium between the ³MLCT state that initiates H-bond dynamics with the solvent and the ³MC state that serves as the principal pathway for nonradiative decay. [ABSTRACT FROM AUTHOR]

Ruthenium(II) polypyridyl complexes pro- mote the efficient radical cation Diels-Alder cycloaddition of electron-rich dienophiles upon irradiation with visible light. These reactions enable facile [4 + 2] cycloadditions that would be electronically mismatched under thermal conditions. Key to the success of this methodology is the availability of ligand-modified ruthenium complexes that enable rational tuning of the electrochemical properties of the catalyst without significantly perturbing the overall photophysical properties of the system. [ABSTRACT FROM AUTHOR]

Examines the large kinetic isotope effects for proton-coupled electron transfer in ruthenium polypyridyl complexes. Importance of nuclear quantum effects; Mechanisms of the electron and proton transfer reactions; Elements of the gas-phase valence bond matrix.

Reports on resonance Raman (RR) and time-resolved resonance Raman (TR3) spectra of ruthenium (II) complexes containing inherently assymetric 2-(2-pyridyl)pyraxzine(pypz) and its selectively deuteriated analogue. Preparation of compounds; Differentiation of `radical' and `neutral ligand' modes; Analysis of `radical' features; Structural interpretation of the TR3 spectrum.

The article offers a description of a ruthenium/chiral diimino-diphosphine (PNNP)-catalyzed asymmetric Diels-Alder reaction. It notes that the PNNP complexes promote the enantioselective Diels-Alder reaction of α-methylene &#03B2;-keto esters to give tetrahydro-1-indanones. It explains that the diene attacks the open re enantioface of metal-bound dienophile in highly enantioselective fashion.

The article reports the first experimental evidence that nuclear isotopic substitution of molecular sensitizers can indeed be used to control excited-state interfacial electron injection yields. The synthesis of the ruthenium ammine compounds is very similar to reported procedures for closely related compounds. The extent of the reaction was monitored by infrared spectroscopy, wherein the N-H stretching modes decreased with a concomitant increase of the N-D stretching intensity. It was found that the N-H stretching bands were essentially gone after four consecutive exchanges in MeOD.

Reports on the coupling of propargyl alcohols through allenylidene-alkynyl or vinylvinylidene-alkynyl combination on a thiolate-bridged diruthenium center. Syntheses and crystal structures of diruthenacyclopentanone and diruthenacyclopentenone complexes; Interaction of organic and organometallic propargyl derivatives with transition metals.