Chemistry of 3-arylindenones: behavior in superacids and photodimerization

In superacids HSO₃F and CF₃SO₃H, it has been found that 3-arylindenones are very stable and exist as a doubly protonated species. NMR showed protonation both at the oxygen of the carbonyl group and at the C2 carbon of the indenone system. 3-Arylindenones proved however very sensitive to heat and light. Their [2+2] photodimerization under daylight has been studied.     

Resonant and nonresonant contributions from unphysical regions in dispersion relations

Unphysical regions on the right hand cut in partial wave dispersion relations for a two-particle processA+B→A′+B′ are expressed by measurable quantities, under the assumption that there is only one important 2-particle channel in the unphysical region. The solution is unique, if the phase shiftδ _l for the elastic scattering in the channel responsible for the appearance of the unphysical region takes a value between 0 andπ at the physical threshold forA+B→A′+B′. The difference between non resonant (δ_l≠π/2 in the unphysical region) and resonant contributions is shortly discussed.     

Palladium

Ohne Zusammenfassung     

Kleine Gehalte an Mangan in Legierungen von Magnesium mit den Seltenen

Ohne Zusammenfassung