Betaine [(CH(3))(3)N(+)CH(2)COO(-)] is a methylated version of glycine and is a zwitterion in its neutral form. In this work, we have subjected protonated betaine, (+)(CH(3))(3)NCH(2)COOH, to a range of fragmentation experiments which involve vibrational excitation, electronic excitation and electron capture. Low-energy (eV) collisions in combination with deuterium labelling reveal that the low...

Accurate G3(MP2)-RAD calculations are used to predict 264 R-H, R-CH3, R-Cl and R-R bond dissociation energies for a wide-ranging test set of carbon and non-carbon centred R˙ radicals. The data are used to calculate a set of inherent and transferrable radical stabilization energies, denoted RSEEt, which ranks the inherent stability of the 66 radicals studied on the same relative scale, irrespect...

Introduction and Survey A. Molecular Nature of Pure Water B. Dissociation and Electrical Conduction Measurements c. Isotope Effects D. Chemical Reactions Involving Proton Transfer Potential Energy Surfaces A. Bond Breakage B. Hydrated Proton C. Hydrated Hydroxide General Theory of Association-Dissociation Reactions A. Definition of Chemical Species B. Molecular Distribution Functions c. Linear ...

For the paradigmatic case of H(2) dissociation, we compare state-of-the-art many-body perturbation theory in the GW approximation and density-functional theory in the exact-exchange plus random-phase approximation (RPA) for the correlation energy. For an unbiased comparison and to prevent spurious starting point effects, both approaches are iterated to full self-consistency (i.e., sc-RPA and sc...

Dissociation of O2 into atomic oxygen is a significant route for O2 activation in metal-catalyzed oxidation reactions. In this study, we systematically investigated the mechanisms of O2 dissociation and the promoting role of water on nine transition metal (Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, and Au) surfaces. It was found that on clean metal surfaces, the dissociation of O2 was most favorable on Co...

Transition metal-catalysed processes have been widely used for the functionalization of inert C?H bonds. Strategies benzylic position having a relatively weak bond (bond dissociation energy? 80–90 kcal/mol) differ from aliphatic and aromatic positions with stronger The recent advances in direct activation through generation C(sp3) radicals demonstrated potential electrochemistry photochemistry ...

The bond energy of molecular fragments to metal surfaces is of great fundamental importance, especially for understanding catalytic reactivity. Thus, the energies of adsorbed intermediates are routinely calculated to understand and even predict the activity of catalytic materials. By correlating our recent calorimetry measurements of the adiabatic bond dissociation enthalpies of three oxygen-bo...

AFM-based dynamic single-molecule force spectroscopy was used to stretch carboxymethylated amylose (CMA) polymers, which have been covalently tethered between a silanized glass substrate and a silanized AFM tip via acid-catalyzed ester condensation at pH 2.0. Rupture forces were measured as a function of temperature and force loading rate in the force-ramp mode. The data exhibit significant sta...

The effect of molecular dissociation on the exchange-correlation Kohn-Sham potential vxc has been studied by the construction of vxc from the ab initio correlated density r for the monohydrides XH ~X5Li, B! at several bond distances R~X—H!. The molecular dissociation manifests itself in the formation of a characteristic peak of vxc in the bonding region. The partially integrated conditional pro...