NATURE OF PEROXY INTERMEDIATES PRODUCER BY THE PHOTOSENSITIZED OXYGENATION OF DIETHYL SULFIDE AND PHENYLBENZOYL DIAZOMETHANE: KINETIC STUDIES BY CO-OXIDATION WITH 4-MONO SUBSTITUTED DIPHENYL SULFIDES

Abstract— Competitive oxidations of pairs of 4-monosubstituted diphenyl sulfides by intermediates produced in the photosensitized oxygenation of diethyl sulfide and phenylbenzoyl diazomethane were carried out in methanol and benzene, respectively. Relative rates of oxidation correlate well with Ham-mett's a, and p values of -0.61 (oxidation in the presence of diethyl sulfide) and -0.32 (oxidation in the presence of phenylbenzoyl diazomethane) show that the diphenyl sulfides oxidizing intermediates have electrophilic character. In the photosensitized oxygenation of sulfides and diazo compounds, peroxy intermediates (a persulfoxide and a carbonyl oxide, respectively) have been proposed as the most probable intermediates.     

Sulfurization of 1,4,7,10-tetraarylcyclododeca-1,2,3,7,8,9-hexaenes

Thermal reactions of 1,4,7,10-tetraarylcyclododeca-1,2,3,7,8,9-hexaenes1a and1b with elemental sulfur were examined, and found to give novel transannular bridged pentasulfides2a and2b, while cyclopentenethiones3a and3b were obtained by the sulfurization of1a and1b in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene.     

Polarization of recoil protons from proton Compton scattering in the region of the second πN resonance

The polarization of recoil protons from proton Compton scattering has been measured at an angle of 90° c.m.s. in the region of the second nucleon resonance. The scattered photons were detected by a telescope which consisted of a lead plate converter, scintillation-counter hodoscopes and a ?erenkov counter, The angles and momenta of recoil protons were analyzed by a magnet with four spark chambers. The polarization of protons was obtained from the asymmetry in the elastic scattering of protons on carbon in a spark chamber.     

On a multivariate normal probability minimization problem

Given a 2k component (column) vector z=(x′,y′)′, x′=(x₁,…, x_k), y′= (y₁,…,y_k), having a 2k variate multivariate normal distribution with mean vector zero, and an unknown 2k×2k positive definite correlation matrix Σ, Shafer and Olkin (1983) conjecture that P(x,y)=P{|x₁|<c,…,|x_k|<c,|y₁|<c,…,|y_k|<c} is minimized when Σ has a certain pattern. This conjecture is proved to be correct. A known inequality is generalized.