The electron affinity of astatine
Abstract
One of the most important properties influencing the chemical behavior of an element is the energy released with the addition of an extra electron to the neutral atom, referred to as the electron affinity (EA). Among the remaining elements with unknown EA is astatine, the purely radioactive element 85. Astatine is the heaviest naturally occurring halogen and its isotope At is remarkably well suited for targeted radionuclide therapy of cancer. With the At anion being involved in many aspects of current astatine labelling protocols, the knowledge of the electron affinity of this element is of prime importance. In addition, the EA can be used to deduce other concepts such as the electronegativity, thereby further improving the understanding of astatine's chemistry. Here, we report the first measurement of the EA for astatine to be 2.41578(7)eV. This result is compared to state-of-the-art relativistic quantum mechanical calculations, which require incorporation of the electron-electron correlation effects on the highest possible level. The developed technique of laser-photodetachment spectroscopy of radioisotopes opens the path for future EA measurements of other radioelements such as polonium, and eventually super-heavy elements, which are produced at a one-atom-at-a-time rate.
Cite
@article{arxiv.2002.11418,
title = {The electron affinity of astatine},
author = {David Leimbach and Julia Sundberg and Yangyang Guo and Rizwan Ahmed and Jochen Ballof and Lars Bengtsson and Ferran Boix Pamies and Anastasia Borschevsky and Katerina Chrysalidis and Ephraim Eliav and Dmitry Fedorov and Valentin Fedosseev and Oliver Forstner and Nicolas Galland and Ronald Fernando Garcia Ruiz and Camilo Granados and Reinhard Heinke and Karl Johnston and Agota Koszorus and Ulli Koester and Moa K. Kristiansson and Yuan Liu and Bruce Marsh and Pavel Molkanov and Lukas F. Pasteka and Joao Pedro Ramos and Eric Renault and Mikael Reponen and Annie Ringvall-Moberg and Ralf Erik Rossel and Dominik Studer and Adam Vernon and Jessica Warbinek and Jakob Welander and Klaus Wendt and Shane Wilkins and Dag Hanstorp and Sebastian Rothe},
journal= {arXiv preprint arXiv:2002.11418},
year = {2020}
}