Ordering of Ruthenium Cluster Carbonyls in Mesoporous Silica

• Published in: Science (American Association for the Advancement of Science) Vol. 280; no. 5364; pp. 705 - 708
• Main Authors: Zhou, Wuzong, Thomas, John Meurig, Shephard, Douglas S., Brian F. G. Johnson, Ozkaya, Don, Maschmeyer, Thomas, Bell, Robert G., Ge, Qingfeng
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 01-05-1998; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Alkenes; Anions; Atomic and molecular clusters; Atomic and molecular physics; Chemistry; Computer Simulation; Electronic Equipment; Exact sciences and technology; Exhibits; Fourier transformations; Hydrogenation; Images of transformations; Infrared radiation; Inhalants; Materials; Metals; Nanoparticles; Nanotechnology; Physics; Ruthenium; Salts; Studies of special atoms, molecules and their ions; clusters; Ionic cluster; Ordered systems; Catalysts; Intermolecular forces; Ruthenium Carbonyls Complexes; Van der Waals forces; Porous materials; Polynuclear complex; Anionic complex; Silica; Mesoporosity
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.280.5364.705

The anionic ruthenium cluster carbonylates [Ru$_6$C(CO)$_{16}$]$^{2-}$ or [H$_2$Ru$_{10}$(CO)$_{25}$]$^{2-}$ interspersed with bis(triphenylphosphino)iminium counterions (PPN$^+$) are incorporated from solution into the pores of MCM-41 mesoporous silica (3 nanometers in diameter), where they form tightly packed arrays. These arrays were shown by high-resolution transmission electron microscopy, Fourier transform optical diffraction, and computer simulations to be well ordered both along and perpendicular to the axis of the cylindrical pores. In their denuded state produced by gentle thermolysis, the cluster carbonylates yield nanoparticles of ruthenium that are less well ordered than their assimilated precursors but show good activity as hydrogenation catalysts for hexene and cyclooctene. In both their as-prepared and denuded states, these encapsulated clusters are likely to exhibit interesting electronic and other properties.