Thomas Albrecht-Schoenzart

Elements beyond plutonium are rich testbeds for probing how relativistic effects alters electronic structure and hence molecular structure, physical properties, and reactivity.  Curium, berkelium, californium, and einsteinium are the final elements for which bulk properties such as X-ray diffraction, optical spectroscopy, and magnetism can be measured, albeit with great difficulty.  These measurements have proven to be well worth the effort and have revealed evidence for a break in the fundamental properties of actinide elements that starts in the actinide series at californium and strengthens through einsteinium, fermium, and mendelevium.  Establishing the onset of this step-function in chemistry required challenging experiments with the highly unstable isotope berkelium-249.  The evaluation of these experimental results with relativistic quantum mechanical theory has helped to explain these unusual observations.  This lecture will conclude with current efforts to push the boundaries of chemistry deeper into the periodic table.