American scientists managed to conduct a series of chemical and physical experiments with a record low amount of einsteinium: they had less than 200 nanograms of this radioactive metal at their disposal. Experts have discovered several new and clarified the already known properties of the transuranic element. The knowledge gained will help in working with other actinides, and also shed light on a number of common properties for the elements at the end of the periodic table.
The study of transuranic elements, that is, having an atomic number higher than 92, is not easy: most of their isotopes have a short half-life. Among them, einsteinium (Es) stands out - the chemical element with the highest atomic number (99) of those that have been obtained in macroscopic quantities. True, this required colossal efforts. And even despite this achievement of scientists, many of its properties are still not fully understood.
This knowledge gap was filled by American experts from Los Alamos National Laboratory (LANL), Lawrence Berkeley National Laboratory (LBNL) and Georgetown University. They published the results of their research in the peer-reviewed journal Nature. The scientists did not work with absolutely pure Einsteinium, but with its isotope Es-254 in conjunction with the chelating ligand hydroxypyridinone.
Many of the physical and chemical properties of Einsteinium have been determined as a result of theoretical calculations and previous experiments. However, such data always require re-verification, moreover, new research has every chance to bring new discoveries. This happened this time as well. Although scientists did not learn anything revolutionary, it was possible to clarify some features of both Es and other actinides.
The researchers refined the length of the Einsteinium chemical bond in different compounds using X-ray absorption spectroscopy. Also, during photophysical measurements, a blue shift was observed, which did not occur in similar experiments with lighter actinides. Finally, researchers have received a lot of data about the structure of the outer electron shells of einsteinium. As the scientists summarize their work, all this new information suggests the need to continue studying the unusual behavior of actinides, especially their short-lived isotopes.
A certain romantic aura of this scientific work is given by the setting in which it was conducted. Einsteinium research is always a race with natural physicochemical phenomena, primarily with its decay. As the authors of the article explained to Sciencealert, in a pandemic, when the functioning of all institutions, it was not easy to carry out all the procedures. Although the most stable isotope, Es-254, with a half-life of just over 275 days, was studied, there was a high probability that the metal obtained in the laboratory simply would not be enough for all experiments.