Cao Kecheng, Skowron Stephen T, Biskupek Johannes, Stoppiello Craig T, Leist Christopher, Besley Elena, Khlobystov Andrei N, Kaiser Ute
Central Facility for Materials Science Electron Microscopy, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany.
School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
Sci Adv. 2020 Jan 17;6(3):eaay5849. doi: 10.1126/sciadv.aay5849. eCollection 2020 Jan.
Metallic bonds remain one of the most important and least understood of the chemical bonds. In this study, we generated Re molecules in which the Re-Re core is unsupported by ligands. Real-time imaging of the atomic-scale dynamics of Re adsorbed on a graphitic lattice allows direct measurement of Re-Re bond lengths for individual molecules that changes in discrete steps correlating with bond order from one to four. Direct imaging of the Re-Re bond breaking process reveals a new bonding state with the bond order less than one and a high-amplitude vibrational stretch, preceding the bond dissociation. The methodology, based on aberration-corrected transmission electron microscopy imaging, is shown to be a powerful analytical tool for the investigation of dynamics of metallic bonding at the atomic level.
