Prof Nik Kaltsoyannis - Seventeen-Coordinate Actinide Helium Complexes
Sweet seventeen: ACIE paper predicts a new world record coordination number
Work by Prof. Nik Kaltsoyannis has explored computationally the geometries and electronic structures of molecular ions featuring He atoms complexed to actinide cations. Density functional and coupled cluster theories are used to establish a new record coordination number, as AcHe173+, ThHe174+ and PaHe174+ are all found to be true geometric minima, with the He atoms clearly located in the first shell around the actinide, beating the previous record coordination number of 16. Analysis of AcHen3+ (n = 1–17) using the Quantum Theory of Atoms in Molecules confirms these systems as having closed shell, charge induced dipole bonding. Given the scarcity and radioactivity of actinium and protactinium, ThHe174+ is the much the most likely of the new CN 17 systems to be experimentally accessible.
Nikolas Kaltsoyannis, Angewandte Chemie International Edition 55 (2017) DOI: 10.1002/anie.201700245R1