Osmium Atoms and Os2 Molecules Move Faster on Selenium-Doped Compared to Sulfur-Doped Boronic Graphenic Surfaces

• Published in: Chemistry of materials 2015-07, Vol.27 (14), p.5100-5105
• Main Authors: Barry, Nicolas P. E, Pitto-Barry, Anaïs, Tran, Johanna, Spencer, Simon E. F, Johansen, Adam M, Sanchez, Ana M, Dove, Andrew P, O’Reilly, Rachel K, Deeth, Robert J, Beanland, Richard, Sadler, Peter J
• Format: Article
• Language: English
• Subjects: Anchoring; Block copolymers; Deposition; Electron bombardment; Exploitation; Micelles; Osmium; Transmission electron microscopy
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/acs.chemmater.5b01853

We deposited Os atoms on S- and Se-doped boronic graphenic surfaces by electron bombardment of micelles containing 16e complexes [Os­(p-cymene)­(1,2-dicarba-closo-dodecarborane-1,2-diselenate/dithiolate)] encapsulated in a triblock copolymer. The surfaces were characterized by energy-dispersive X-ray (EDX) analysis and electron energy loss spectroscopy of energy filtered TEM (EFTEM). Os atoms moved ca. 26× faster on the B/Se surface compared to the B/S surface (233 ± 34 pm·s–1 versus 8.9 ± 1.9 pm·s–1). Os atoms formed dimers with an average Os–Os distance of 0.284 ± 0.077 nm on the B/Se surface and 0.243 ± 0.059 nm on B/S, close to that in metallic Os. The Os2 molecules moved 0.83× and 0.65× more slowly than single Os atoms on B/S and B/Se surfaces, respectively, and again markedly faster (ca. 20×) on the B/Se surface (151 ± 45 pm·s–1 versus 7.4 ± 2.8 pm·s–1). Os atom motion did not follow Brownian motion and appears to involve anchoring sites, probably S and Se atoms. The ability to control the atomic motion of metal atoms and molecules on surfaces has potential for exploitation in nanodevices of the future.