Observation of nonresonant coulomb break-up of 156 MeV6Li projectiles

The neutron coherent scattering length b_c=9.26(13) fm of the lead isotope²⁰⁸Pb was determined by neutron interferometry.     

Identification of an activated catalyst in the iridium-catalyzed allylic amination and etherification. Increased rates, scope, and selectivity

Studies were conducted to determine possible intermediates in the highly enantioselective, iridium-catalyzed amination and etherification of allylic carbonates, and these studies revealed that cyclometalation of the phosphoramidite ligand is likely to generate the active catalyst. The square-planar [Ir(COD)(L1)Cl] (L1 = P(BINOL)(bisphenethylamine)) did not react with cinnamyl carbonate, but did react with amine to generate an Ir(I) trigonal bipyramidal complex coordinated by COD, a cyclometalated kappa2-phosphoramidite, and a kappa1-phosphoramidite. This complex reacted with phosphines to generate products from replacement of the kappa1-phosphoramidite. These cyclometalated complexes were highly active catalysts for allylic amination and etherification and retained the high selectivity of the original catalyst system. In addition, these complexes combined with [Ir(cod)Cl]2 catalyzed reactions of amines with lower loadings, catalyzed reactions of alkylamines and aromatic amines that did not react with the original catalyst system, and catalyzed reactions of phenoxides under milder conditions.     

Hydrogen burning of 17O in classical novae

We report on the observation of a previously unknown resonance at E(lab)(R)=194.1+/-0.6 keV in the 17O(p,alpha)14N reaction, with a measured resonance strength omegagamma(palpha)=1.6 +/- 0.2 meV. We studied in the same experiment the 17O(p,gamma)18F reaction by an activation method and the resonance-strength ratio was found to be omegagamma(palpha)/omegagamma(pgamma) = 470 +/- 50. The corresponding excitation energy in the 18F compound nucleus was determined to be 5789.8 +/- 0.3 keV by gamma-ray measurements using the 14N(alpha, gamma)18F reaction. These new resonance properties have important consequences for 17O nucleosynthesis and gamma-ray astronomy of classical novae.     

Intermediate mass fragments in the reaction6Li+46Ti atE/A=26 MeV

Intermediate mass fragment cross-sectionsσ(E, θ, 4≤Z≤11) have been measured in the reaction⁶Li+⁴⁶Ti at 156 MeV incident energy. A simple sequential binary decay model describes most of theZ>8 data as evaporation from the compound nucleus. The complete fusion cross-section is also well reproduced. An intermediate velocity source model (β=2β _CN, T=7 MeV) has been used in order to explain the small angle and Z≤8 data which indicate aZ ^?4.1 dependence.