Chemistry of the actinide elements represents a challenging yet vital scientific frontier. Development of actinide chemistry requires fundamental understanding of the relative roles of actinide valence-region orbitals and the nature of their chemical bonding. We report here an experimental and theoretical investigation of the uranium methylidyne molecules X3U'CH (X F, Cl, Br), F2ClU'CH, and F3U...

Recent advances in computational actinide chemistry are reported in this tutorial review. Muticonfigurational quantum chemical methods have been employed to study the gas phase spectroscopy of small actinide molecules. Examples of actinide compounds studied in solution are also presented. Finally the multiple bond in the diuranium molecule and other diactinide compounds is described.

The vacuum ultraviolet (VUV)/soft X-ray region of the synchrotron radiation (SR) spectrum has revolutionised the approach to surface materials chemistry/physics. This spectral region has long been recognised for its potential to afford investigations of fundamental actinide science and to provide an improved analytical surface characterisation capabilities for actinide materials. Previously, th...

Systematic trends of mononuclear and polynuclear hydrolysis constants of tetravalent actinide ions were analyzed by using an electrostatic hard sphere model. The effective charges of actinide ions were introduced into the model by considering possible contributions of non-electrostatic interactions of actinide ions in addition to those of ordinary electrostatic ones. The systematic trends of hy...

One of the long standing debates in actinide chemistry is the level of localization and participation of the actinide 5f valence orbitals in covalent bonds across the actinide series. Here we illuminate the role of the 5f valence orbitals of uranium, neptunium and plutonium in chemical bonding using advanced spectroscopies: actinide M4,5 HR-XANES and 3d4f RIXS. Results reveal that the 5f orbita...

Several workshops, some dating back more than fifteen years, recognised both the potential scientific impact and opportunities that would be made available by the capability to investigate actinide materials in the vacuum ultraviolet (VUV)/soft X-ray region of the synchrotron radiation (SR) spectrum. This spectral region revolutionised the approach to surface materials chemistry and physics nea...

— The present status of our information on the thermodynamics of the actinide halogeno-complexes with alkali metal ions is reviewed, with special emphasis on chloroand bromo-derivatives. Where enough thermodynamic and structural data are available, attempts are made to deduce the evolution of the energetics of the actinide-halogen bonds along a series of isomorphous or analogous compounds. The ...

The field of actinide chemistry is still young, not least because the radioactivity of these elements makes them difficult to work with. A study now reveals details of how actinide compounds might behave in water.

3 FOREWORD The separation of actinide elements from various waste materials is a significant problem facing developed countries. The issue arises primarily because of the potential long-term hazard of many of the actinides, but is also due to the regulatory requirements associated with actinide waste disposal, which are different from those associated with other radioactive wastes. The differen...

This study investigates actinide burning in a standard lattice PWR. It assumes that after the first loading of depleted uranium, plutonium and minor actinides, only the fission products are removed and only depleted uranium and the plutonium/minor actinide mixture are added. The relative concentrations of plutonium and minor actinide feed are always maintained the same as PWR discharge fuel aft...