Solvated Electron in Acetonitrile: Radiation Yield, Absorption Spectrum, and Equilibrium between Cavity- and Solvent-Localized States.

The equilibrium between a solvent cavity-localized electron, e, and a dimeric solvent anion, (CHCN), which are the two lowest energy states of the solvated electron in acetonitrile, has been investigated by pulse radiolysis at 233-353 K. The enthalpy and entropy for the e to (CHCN) conversion amount to -11.2 ± 0.

Hydrogen bonding between hydroxylic donors and MLCT-excited Ru(bpy)(bpz) complex: implications for photoinduced electron-proton transfer.

The equilibrium constants of the hydrogen bonding (HB) between hydroxylic donors, ROH, and an MLCT-excited Ru(bpy)(bpz) complex, 1(T), correlated with ROH empirical HB acidities, which could be used for evaluating the unimolecular rate constants of concerted electron-proton transfer within the H-bonded phenol-1(T) exciplexes.

Carbon dioxide-catalyzed peroxynitrite reactivity - The resilience of the radical mechanism after two decades of research.

Peroxynitrite, ONOO, formed in tissues that are simultaneously generating NO and O, is widely regarded as a major contributor to oxidative stress. Many of the reactions involved are catalyzed by CO via formation of an unstable adduct, ONOOC(O)O, that undergoes O-O bond homolysis to produce NO and CO radicals, whose yields are equal at about 0.33 with respect to the ONOO reactant.

Solvent-dependent transition from concerted electron-proton to proton transfer in photoinduced reactions between phenols and polypyridine Ru complexes with proton-accepting sites.

The bimolecular rate coefficients (kobsq) for quenching the metal-to-ligand charge transfer excited states of two Ru polypyridine complexes containing H-bond accepting sites by six p-substituted phenols exhibit abrupt deviations from the expected linear correlations of log kobsq with phenol's Hammett σp constant. This pattern is attributed to a transition of the quenching mechanism from a concerted electron-proton transfer (EPT) to a proton transfer (PT); the latter becomes predominant for the most acidic phenols in acetonitrile, but not in dichloromethane. This assertion is supported by a detailed thermochemical analysis, which also excludes the quenching pathways involving electron transfer from phenols with or without deprotonation of phenols to the solvent, either concerted or sequential.

Beyond fossil fuel-driven nitrogen transformations.

Nitrogen is fundamental to all of life and many industrial processes. The interchange of nitrogen oxidation states in the industrial production of ammonia, nitric acid, and other commodity chemicals is largely powered by fossil fuels. A key goal of contemporary research in the field of nitrogen chemistry is to minimize the use of fossil fuels by developing more efficient heterogeneous, homogeneous, photo-, and electrocatalytic processes or by adapting the enzymatic processes underlying the natural nitrogen cycle.