Fast Molecular Compression by a Hyperthermal Collision Gives Bond-Selective Mechanochemistry

• Published in: Physical review letters Vol. 126; no. 5; p. 056001
• Main Authors: Krumbein, Lukas, Anggara, Kelvin, Stella, Martina, Michnowicz, Tomasz, Ochner, Hannah, Abb, Sabine, Rinke, Gordon, Portz, André, Dürr, Michael, Schlickum, Uta, Baldwin, Andrew, Floris, Andrea, Kern, Klaus, Rauschenbach, Stephan
• Format: Journal Article
• Language: English
• Published: United States American Physical Society 05-02-2021
• Subjects: Bends; Collision dynamics; Ion beams; Kinetic energy; Reaction products; Scanning tunneling microscopy; Thermalization (energy absorption); Time
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.126.056001

Using electrospray ion beam deposition, we collide the complex molecule Reichardt's dye (C_{41}H_{30}NO^{+}) at low, hyperthermal translational energy (2-50 eV) with a Cu(100) surface and image the outcome at single-molecule level by scanning tunneling microscopy. We observe bond-selective reaction induced by the translational kinetic energy. The collision impulse compresses the molecule and bends specific bonds, prompting them to react selectively. This dynamics drives the system to seek thermally inaccessible reactive pathways, since the compression timescale (subpicosecond) is much shorter than the thermalization timescale (nanosecond), thereby yielding reaction products that are unobtainable thermally.