A measurement of π+p backward elastic differential cross sections from 1.282 to 2.472 GeV/c

New high-statistics measurements of π⁺p elastic scattering differential cross sections are presented at 30 momentum points between 1.282 and 2.472 GeV/c, covering most of the angular distribution outside the forward diffractive peak. These data show significant disagreements at some momenta with previous high-statistics experiments and with current partial wave analyses.     

Asymmetric transfer hydrogenation of α,β-unsaturated, α-tosyloxy and α-substituted ketones

Asymmetric transfer hydrogenation of cyclic and acyclic α,β-unsaturated ketones catalysed by η⁶-p-cymene/ruthenium(II) and η⁵-pentamethylcyclopentadienyl/rhodium(III) complexes have been investigated. Cyclic α,β-unsaturated ketones appeared to be more suitable substrates for the synthesis of enantiomerically pure allylic alcohols than do acyclic α,β-unsaturated ketones. A proposed mechanism for the formation of 4-phenyl-[1,3]-dioxolan-2-one from α-tosyloxy- and halo-substituted acetophenones is discussed. The results of further investigations into the reduction of a range of α-tosyloxyacetophenones and the dynamic kinetic resolution of α-substituted ketones is presented.     

The mass spectra of some pentafluorophenylthio derivatives

Ionic fragmentations induced by electron-impact on compounds of the type C₆F₅SX (X ? H, CH₃, COCH₃, Cl, C₆F₅) and (C₆F₅S)₂, (C₆F₅S)₂Hg, (C₆F₅S)₃As and (C₆F₅SCH₂)₂ have been studied. Principal features of the mass spectra are reported. The [C₆F₅S]⁺ ion (m/e 199) is predominant and its mode of fragmentation has been deduced. The precursor ions for m/e 199 have been examined in (C₆F₅)₂S, (C₆F₅S)₂, (C₆F₅S)₂Hg, (C₆F₅S)₃As and C₆F₅SCl. Ion kinetic energy spectra of (C₆F₅)₂S, (C₆F₅S)₂, (C₆F₅S)₂Hg and C₆F₅SCl have been recorded, and all contain peaks corresponding to the fragmentation of the [C₆F₅S]⁺ ion.     

Theory of the pressure broadening and shift of spectral lines

The broadening and shift of spectral lines caused by the interaction of the emitting (or absorbing) atoms with surrounding particles in the plasma are commonly observed in laboratory and astronomical spectra. A detailed analysis of the observed line shapes can give information about the density and temperature of the plasma, and in cases where the interaction between emitter and perturber is not known, some information on its form may be deduced.     

The thiolate anion as a nucleophile Part XI. Effect of the size of the nucleophile

The nucleophilic substitution reactions of some simple fluorobenzenes, C₆H_6?xF_x with sodium methanethiolates Na⁺SR^?(R=Et, $\text{i}$-Pr, $\text{t}$-Bu) have been studied. Some fully substituted products, C₆H_6?x(SR)_x, could be obtained in DMF as solvent with R = Et and $\text{i}$-Pr, but not when R = $\text{t}$-Bu. All the new products isolated have been characterized by elemental analysis, and NMR (H-1 and F-19), infrared and mass spectroscopy.