Iodine(III)‐Catalyzed Rearrangements of Imides: A Versatile Route to α,α‐Dialkylated α‐Hydroxy Carboxylamides

A tertiary hydroxy group α to a carboxyl moiety comprises a key structural motif in many bioactive substances. With the herein presented metal‐free rearrangement of imides triggered by hypervalent λ³‐iodane, an easy and selective way to gain access to such a compound class, namely α,α‐disubstituted‐α‐hydroxy carboxylamides, was established. Their additional methylene bromide side chain constitutes a useful handle for rapid diversification, as demonstrated by a series of further functionalizations. Moreover, the in situ formation of an iodine(III) species under the reaction conditions was proven. Our findings clearly corroborate that hypervalent λ³‐benziodoxolones are involved in these organocatalytic reactions.     

Identification of iodoorganic compounds in kerosene from nuclear fuel reprocessing

In kerosene samples from nuclear fuel reprocessing, iodoalkanes with chain-lengths from C₄ to C₁₃ have been identified. The kerosene samples were purified by means of solid-phase extraction. By this method other fission products like¹²⁵Sb and¹⁰⁶Ru were quantitatively removed from the solution. The only remaining radioactive nuclide was thus¹²⁹I. The iodoorganic compounds in the kerosene from the solvent were enriched from 6000 Bq/L to 100 000 Bq/L¹²⁹I by vacuum distillation. Chromatographic separation by HPLC, fractionation, and -measurement of the fractions showed that at least one polar and one nonpolar iodoorganic compound were present. Derivatisation of the iodoorganic compounds with, 1,4-diazabicyclo-2,2,2-octane to quatermary ammonium salts and²⁵²Cf plasma desorption mass spectrometry of the products revealed that the main iodoorganic constituents in the kerosene were iodobutane as polar and iodododecane as nonpolar compound in approximately equal concentrations.     

O-Insertion into Nonactivated C?H Bonds: The first observation of O2 cleavage by a P-450 enzyme model in the presence of a thiolate ligand

On reaction with ‘O’-donors or O₂, the synthetic P-450 analogue 2 undergoes O-insertion at a nonactivated C? H bond of the covalently bound substrate. The mechanism of O-insertion with O₂ most likely involves homolytic cleavage of the O? O bond followed by O-insertion via radical recombination.     

Chernobyl radioactivity in Turkish tea

Radioactivity in Turkish tea of the 1986 crops was measured. Doses were calculated for persons drinking customarily tea.     

The decay of 187Pt: Comparison of the levels of 187Ir with those of heavier odd mass iridium isotopes

The decay scheme of 2.35 h ¹⁸⁷Pt has been investigated using isotopically separated samples produced by the ISOLDE facility at CERN. A total of 20 excited levels in ¹⁸⁷Ir have been established. For many of these levels, spin, parity and absolute probabilities of depopulating transitions have been determined. The results indicate that the ¹⁸⁷Ir nucleus can be described in terms of a single particle Nilsson model including Coriolis coupling between bands ($\text{3}\text{2}{}^{\mathrm{+}}\text{[402],}\text{1}\text{2}{}^{\mathrm{+}}\text{[400]}$).     

Decay properties of neutron deficient Kr isotopes

The decay properties of the neutron deficient isotopes^73–77Kr and^73–76Br have been studied at the ISOLDE facility at CERN. The total decay energiesQ, as determined fromβ ⁺ singles orβ ⁺ -γ coincidence measurements, are compared with mass formulae.     

Search for a new reaction mechanism in the system132Xe+natFe

Thin targets of natural Fe have been irradiated with¹³²xe ions at beam energies of 5.00, 5.90, and 7.15 MeV/u. Mass yields for projectile-like and symmetric products were evaluated, and their ratio as a function of beam energy determined. The results are consistent with previously-determined thick-target radiochemical data, and are not consistent with published on-line counter data for the same system.     

Fusion-like processes and the concept of dynamic equivalence: The system 132Xe + natFe

Cross sections for production of nuclides in the reaction of 4.56, 5.90 and 7.12 $\text{MeV}\text{u}$¹³²Xe ions with thick natural Fe targets were determined, and the corresponding mass- and charge-yield curves have been constructed. The latter are resolved into components corresponding to fusion-fission (symmetric fragmentation), fusion-evaporation, deep-inelastic transfer and quasielastic transfer. The integral excitation functions for fusion and fusion-like processes exhibit very good agreement with the predictions of the dynamic capture model of Swiatecki. Furthermore, the observed extra push energies for this system and those of ²⁰⁸Pb + ⁴⁸Ca show very similar dependencies on the corresponding entrance-channel orbital energies, in line with the model prediction that these systems should be dynamically equivalent.