We present accurate state-to-state quantum wave packet calculations of integral cross sections and rate constants for the title reaction. Calculations are carried out on the best available ground 1(2)A' global adiabatic potential energy surface of Deskevich et al. [J. Chem. Phys. 124, 224303 (2006)]. Converged state-to-state reaction cross sections have been calculated for collision energies up...

Loss of the A ring in the electron-impact mass spectra of the trimethylsilyl (TMS) derivatives of several cholesterol oxidation products is accompanied by intramolecular migration of the 3-O-TMS group to the charge-retaining portion of the molecule. Linked-scan techniques (B/E and B(2)/E) were used to establish the fragmentation processes leading to the formation of the rearrangement ion. The T...

The rate constants of nitroxide reduction by ascorbate ion were determined from a time-series measurement of ESR images, that is, ESR spatiotemporal images, which were measured with a rapid field scan L-band ESR-CT system. Two test tubes containing the phosphate buffer solutions of 3-carbamoyl-2,2,5,5-tetramethylpyrrolidin-l-yloxy (C-PROXYL) and ascorbate ion with different concentrations were ...

A hybrid atmospheric pressure ion mobility spectrometer is described which exhibits resolving power approaching the diffusion limit for singly and multiply charged ions (over 200 for the most favorable case). Using an electrospray ionization source and a downstream quadrupole mass spectrometer with electron multiplier as detector, this ESI-IMS-MS instrument demonstrates the potential of IMS for...

A mass spectrometric method has been delineated for the identification of the epoxide functionalities in unknown monofunctional analytes. This method utilizes gas-phase ion/molecule reactions of protonated analytes with neutral trimethyl borate (TMB) followed by collision-activated dissociation (CAD) in an ion trapping mass spectrometer (tested for a Fourier-transform ion cyclotron resonance an...

Laser flash photolysis has been used to determine the second-order rate constants for the reduction of horse heart cytochrome c by the semiquinone and fully reduced forms of various flavin analogs. We find that substitution in the dimethylbenzene ring of the flavin causes appreciable changes in the rate constants, whereas substitutions at the N-10 position do not. Placing a charged phosphate gr...

The collision-induced Zeeman relaxation rate for collisions of CaF X2Sigma(v('')=0) with 3He is measured to be Gamma(Z)=(7.7+5.4/-2.5)x10(-15) cm(3)/s at 2 K. This rate is a direct measurement of the influence of spin-rotation coupling on Zeeman relaxation in the first rotational level of CaF. The relationship of this rate to known molecular constants is consistent with recent theory of cold mo...

We study vibrational deactivation processes on chemically reactive potential energy surfaces by examining accurate quantum mechanical transition probabilities and rate constants for the collinear H + FH(v ), D + FD(v), H + FD(v}, and D + FH(v) reactions. A low barrier (1.7 kcal!mole} potential surface is used in these calculations, and we find that for all four reactions, the reactive inelastic...