Nickel silicide has been studied with a range of computational methods to determine the nature of the Ni-Si bond. Additionally, the physical effects that need to be addressed within calculations to predict the equilibrium bond length and bond dissociation energy within experimental error have been determined. The ground state is predicted to be a (1)Σ(+) state with a bond order of 2.41 correspo...

The strength of the O-O bond is of fundamental importance in a variety of chemical processes. Traditionally, a value of 34 kcal/mol has been ascribed to a generic O-O bond dissociation energy. The present, high-level ab initio calculations indicate that the average O-O bond energy is significantly higher, ca. 45 kcal/mol, and that the bond energy is sensitive to the bonding environment. Calcula...

The interaction of prolactin (PRL) with its membrane receptor depends markedly on temperature. Thermodynamic parameters for this reaction have been evaluated from data for time-course kinetics and equilibrium binding at multiple temperatures between 19 and 31 degrees C. The free-energy change with temperature and the van't Hoff plot were found to be linear. These suggest that there are minimal ...

The activation energy to reaction is a key quantity that controls catalytic activity. Having used ab inito calculations to determine an extensive and broad ranging set of activation energies and enthalpy changes for surface-catalyzed reactions, we show that linear relationships exist between dissociation activation energies and enthalpy changes. Known in the literature as empirical Brønsted-Eva...

Isotopic effects on the formation and dissociation kinetics of hydrogen bonds are studied in real time with ultrafast chemical exchange spectroscopy. The dissociation time of hydrogen bond between phenol-OH and p-xylene (or mesitylene) is found to be identical to that between phenol-OD and p-xylene (or mesitylene) in the same solvents. The experimental results demonstrate that the isotope subst...

Ice Ih, the common form of ice in biosphere, contains proton disorder. Its proton-ordered counterpart, XI, is thermodynamically stable below 72 K. However, even this temperature formation XI kinetically hindered and experimentally it obtained by doping with KOH. Doping creates ionic defects that promote migration protons associated change configuration. In article, we mimic effect molecular dyn...

Threshold photoelectron photoion coincidence has been used to prepare selected internal energy distributions of nitrosobenzene ions [C(6)H(5)NO(+)]. Dissociation to C(6)H(5)(+) + NO products was measured over a range of internal energies and rate constants from 10(3) to 10(7) s(-1) and fitted with the statistical theory of unimolecular decay. A 0 K dissociative photoionization onset energy of 1...

Density functional theory calculations based on different representations of the exchange-correlation functional (BLYP, B3LYP, B3PW91, mPW1PW91, B1LYP, BHandHLYP, BHandH, and B3P86) were carried out to predict C–H bond dissociation enthalpies in selected ethers (dimethyl ether, tetrahydrofuran (thf), and 1,4-dioxane), and some related molecules. Comparison with available experimental informatio...

Resonant two-photon ionization spectroscopy has been employed to observe sharp predissociation thresholds in the spectra of lanthanide sulfides and selenides for 4f metals Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Lu. As these molecules possess a large density electronic states near ground separated atom limit, are argued coincide with true 0 K bond dissociation energies (BDEs). This is because spin–...

Polybrominated diphenyl ethers (PBDEs) are hydrophobic organic contaminants with properties and nomenclature similar to polychlorinated biphenyls (PCBs). While much information is available on the bioaccumulation and pharamcokinetics of PCBs, little information is available on PBDEs. In this study, juvenile carp were exposed to a diet spiked with a cocktail of four BDE congeners (2,4,4'-tribrom...