Observation of relativistic bond weakening in seaborgium hexacarbonyl

Nature, Published online: 07 October 2026; doi:10.1038/s41586-026-11105-2

Gas chromatography analysis of compounds formed by the superheavy element seaborgium shows that the hexacarbonyl complex Sg(CO)6 exhibits lower first bond dissociation energy than the lighter chemical homologue W(CO)6, owing to relativistic bond weakening effects.