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The kinetics and mechanism of the reactions of Z-aryl bis(4-methoxyphenyl) phosphates, (4-MeOC(6)H(4)O)(2)P(=O)OC(6)H(4)Z, with pyridines (XC(5)H(4)N) are investigated in acetonitrile at 55.0 degrees C. In the case of more basic phenolate leaving groups (Z = 4-Cl, 3-CN), the magnitudes of beta(X) (beta(nuc)) and beta(Z) (beta(lg)) indicate that mechanism(More)
The gas-phase identity nucleophilic substitution reactions of halide anions (X = F, Cl, and Br) with cyclopropenyl halides, X(-) + (CH)(3)X <= => X(CH)(3) + X(-), are investigated theoretically at four levels of theory, B3LYP/6-311+G**, MP2/6-311+G**, G2(+)MP2//MP2/6-311+G**, and G2(+)//MP2/6-311+G**. Four types of reaction paths, the sigma-attack S(N)2,(More)
We describe a method to measure the concentration of 224 Ra and 226 Ra in the heavy water target used to detect solar neutrinos at the Sudbury Neutrino Observatory and in the surrounding light water shielding. A water volume of 50–400 m 3 from the detector is passed through columns which contain beads coated with a compound of manganese oxide onto which the(More)
As photodisintegration of deuterons mimics the disintegration of deuterons by neutrinos, the accurate measurement of the radioactivity from thorium and uranium decay chains in the heavy water in the Sudbury Neutrino Observatory (SNO) is essential for the determination of the total solar neutrino flux. A radium assay technique of the required sensitivity is(More)
The densities of high energetic molecules in the solid state were calculated with a simplified scheme based on molecular surface electrostatic potentials (MSEP). The MSEP scheme for density estimation, originally developed by Politzer et al., was further modified to calculate electrostatic potential on a simpler van der Waals surface. Forty-one energetic(More)
This article provides the complete description of results from the Phase I data set of the Sudbury Neutrino Observatory (SNO). The Phase I data set is based on a 0.65 kiloton-year exposure of 2 H 2 O (in the following denoted as D 2 O) to the solar 8 B neutrino flux. Included here are details of the SNO physics and detector model, evaluations of systematic(More)
The reactions of ethyl Y-phenyl chloro (1) and chlorothio (2) phosphates with X-anilines in acetonitrile at 55.0 degrees C are studied kinetically and theoretically. Kinetic results yield the primary kinetic isotope effects (k(H)/k(D) = 1.07-1.80 and 1.06-1.27 for 1 and 2, respectively) with deuterated aniline (XC(6)H(4)ND(2)) nucleophiles, and the(More)
The reactions of Z-aryl dimethyl (1), methyl phenyl (2), and diphenyl (3) phosphinates with X-anilines in dimethyl sulfoxide at 60.0 °C are studied kinetically. Kinetic results yield the primary normal deuterium kinetic isotope effects (DKIEs) involving deuterated aniline (XC(6)H(4)ND(2)) nucleophiles, k(H)/k(D) = 1.03-1.17, 1.15-1.29, and 1.24-1.51, and(More)
Kinetic studies of the reactions of aryl phenyl chlorothiophosphates (1) and aryl 4-chlorophenyl chlorothiophosphates (2) with substituted anilines in acetonitrile at 55.0 degrees C are reported. The negative values of the cross-interaction constant rhoXY (rhoXY = -0.22 and -0.50 for 1 and 2, respectively) between substituents in the nucleophile (X) and(More)
The mechanism of Michael addition of malononitrile to chalcones catalyzed by Cinchona alkaloid aluminium(III) complex has been investigated by DFT and ONIOM methods. Calculations indicate that the reaction proceeds through a dual activation mechanism, in which Al(III) acts as a Lewis acid to activate the electrophile α,β-unsaturated carbonyl substrate while(More)