A theoretical treatment of the multipole relaxation and transfer rates due to isotropic collisions is presented. Explicit expressions are obtained for the collisional rate constants of the hyperfine-structured ground level of the Na I atoms perturbed by collisions with H atoms. As the effects of Na nuclear spin during the collision are negligible, it is shown that all the rate constants involve...

Most symmetric quadrupolar molecules designed for two-photon absorption behave as dipolar molecules in the S1 electronic excited state. This is usually explained by a breakup of the symmetry in the excited state. However, the origin of this process and its dynamics are still not fully understood. Here, excited-state symmetry breaking in a quadrupolar molecule with a D-π-A-π-D motif, where D and...

The reaction of hemoglobin with oxygen has been studied by stopped flow methods, and, under suitably restricted conditions, it can be adequately represented by a system of four consecutive reversible reactions. The numerical values given to the eight rate constants permit a satisfactory fit to combination and dissociation velocity data, and yield an equilibrium curve of the appropriate form. Th...

We report proton transfer reaction rate constants between the hydronium ion (H3O ) and selected atmospherically important volatile organic compounds (VOCs). The quantum chemical method was used to determine the structures of the organic species employing the density function theory-B3LYP. The ion–molecule reaction rates were determined using the average-dipole-orientation theory, along with the...

A kinetic master equation for state populations of a quantum system comprised separate subsystems, is derived. The allows one to describe the charge transfer processes in molecular junctions, where molecule operates as transmitter electrons between electrodes. Special attention given derivation contact and distant rate constants responsible formation sequential (hopping) direct (distant) compon...

The reaction of hemoglobin with oxygen has been studied by stopped flow methods, and, under suitably restricted conditions, it can be adequately represented by a system of four consecutive reversible reactions. The numerical values given to the eight rate constants permit a satisfactory fit to combination and dissociation velocity data, and yield an equilibrium curve of the appropriate form. Th...

The development of a structure/reactivity relationship for aqueous phase reactions of organic compounds with OH is presented. An empirical model is used to relate the functional groups of the molecule and the rate constant of the molecule reacting with OH. An artificial neural network, the multi layer perceptron (MLP), is found to be capable of predicting the rate constants, for which the slope...

An exact collision detection algorithm is described and analyzed. The time bound considers the complexity of the solids, number of joints and number of distinct collision configurations. A bound for the number of collision configurations can be taken directly from the input data. The algorithm is based on exact treatment of trigonometric expressions. The representation of trigonometric constant...

Over the past 100 years, deterministic rate equations have been successfully used to infer enzyme-catalysed reaction mechanisms and to estimate rate constants from reaction kinetics experiments conducted in vitro. In recent years, sophisticated experimental techniques have been developed that begin to allow the measurement of enzyme-catalysed and other biopolymer-mediated reactions inside singl...