Edward G. Janzen

A proton and lithium-7 NMR investigation of triphenyl group IV lithium compounds

Abstract The proton NMR spectra of the triphenyl group IV lithium compounds have been analysed exactly in terms of the fundamental parameters, chemical shifts, and coupling constants. The para proton chemical shifts are consistent with electron donation from the group IV atom into the phenyl rings, as was reported previously. However, the para protons are shielded in the opposite order from that expected on the basis of the π-bonding trends of the group IV atoms. The 7Li NMR spectra were also obtained for information concerning the association between Li and the group IV atom. The data indicate that the degree of electron delocalization into the phenyl rings is controlled by the degree of association between lithium and the group IV atom.

Chemiluminescence in the oxidation of phenyl-substituted silole radical anions and dianions

Abstract The emittor in the chemiluminescent electron transfer oxidation of the radical anions and dianions of 1,1-dimethyl-2,5-diphenyl- and 1,1-dimethyl-2,3,4,5-tetraphenylsilole is shown to be the parent compound. Chemiluminescence is reported in the oxidation of the radical anions of 1,2,5-triphenylphosphole, 2,3,4,5-tetraphenylthiophene-5-dioxide and 1,1-diphenyldibenzosilole.

ESR Titration of AS2O3 by Potassium Permanganate

Abstract A rapid esr titration method is described and demonstrated with the As2O3/KMnO4 system. The results indicate that end points can be established with a precision of better than 1% and an accuracy of 0.4%.