Preparation and crystal structure of two bicyclo[1.1.0]butan-2-ones: a hybrid oxyallyl-cyclopropanone motif

The first X-ray crystal structures of two different bicyclo[1.1.0]butanones show a very long transannular bond of 1.69 A and a large carbonyl pyramidal distortion of 0.26 A out of the plane of the three carbons. These features are those expected of molecules with a hybrid cyclopropanone-oxyallyl structure, and these structures differ markedly from those of the parent bicyclo[1.1.0]butane skeleton.     

Production of slow singly charged fragments in 200 GeV/c hadron nucleus interactions

Measurements of slow, singly charged fragments in the target rapidity region have been performed for proton and pion induced reactions with various nuclei at 200 GeV/c. Multiplicity, angular and energy distributions are examined and used to study the effects of rescattering in the nuclear medium. Data are compared to a geometric cascade model and to simulations with the VENUS 3.11 and the FRITIOF 1.7 Monte Carlo codes.     

13C NMR spectra of η3 -allylmanganesetetracarbonyl compounds; structural implications

The ¹³C NMR spectra of η³-allylmanganese tetracarbonyl complexes are consistent with an overall C_s, symmetry and involving a σ_v plane in the Mn(CO)₄ fragment. A dynamic carbonyl interchange process was looked for but the results are inconclusive, however the barrier for this process is certainly greater than 42 kJ/mol. This observation suggests an octahedral type geometry rather than a square pyramid type configuration.