Osmium Atoms and Os₂Molecules Move Faster on Selenium-Doped Compared to Sulfur-Doped Boronic Graphenic Surfaces

Abstract

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–1versus 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.

Pseudo electron-deficient organometallics: limited reactivity towards electron-donating ligands

“…Our group has recently developed a strong interest in two 16-e ruthenium and osmium half-sandwich complexes based on a carborane ligand ([Ru/Os(η 6 -p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-dithiolato)]), and investigated their applications in biology 16,34,35 and in the fabrication of nanomaterials. [36][37][38][39] The intriguing chemistry in solution of these electron-deficient complexes was also studied in order to understand their biological properties. [40][41][42] Owing to the steric hindrance of the bulky carborane ligand, which prevents the dimerization of the compounds and the formation of more electronic favored 18-e species, these metal-carboranes exhibit remarkable stability as 16-e monomeric species as first demonstrated by Jin and co-workers.…”

Synthesis and controlled growth of osmium nanoparticles by electron irradiation

“…We recently introduced a new method for the fabrication of small (1 to 2 nm diameter) crystalline MNPs. 14,15 Our procedure involved the encapsulation of the organometallic Os II complex [Os( p-cymene)(1,2-dicarba-closo-dodecarborane-1,2dithiolate)] (1) in the triblock copolymer Pluronic ® P123 16 to form OsMs micelles ( Fig. 1, and ESI †).…”

Effect of Temperature on the Nucleation and Growth of Precious Metal Nanocrystals

“…Nonetheless, it is obvious that the nanocluster growth is directly influenced by the temperature of the grid. These results indicate that the effect of temperature on the nanocluster growth is of the same order of magnitude as the effect of underlying doping heteroatoms in the surface (26 times faster on Se‐doped surfaces than on S‐doped surfaces; 2 times faster on B‐doped surfaces compared to B‐free surfaces). Temperature has also an effect of the same order of magnitude as the nature of the metal used to produce the nanoclusters.…”