Thermal decomposition of [M3(CO)12] (M=Ru, Os) physisorbed onto porous Vycor glass: a route to a glass/RuO2 nanocomposite

Abstract

This paper reports the preparation and characterization of oxide/glass nanocomposites, obtained by the impregnation and thermal decomposition of the trinuclear metal carbonyl clusters [M 3 (CO) 12 ] (M=Ru, Os) inside the pores of porous Vycor glass (PVG). The intermediate species formed during the thermal treatment of the [M 3 (CO) 12 ] adsorbed PVG materials were studied by UV-VIS-NIR and diffuse reflectance infrared (DR-IR) spectroscopy. At 65°C (M=Ru) and 110°C (M=Os), formation of surface bound [ HM 3 (CO) 10 (m-OSiM)] species occurs, as a result of oxidative addition of a PVG surface silanol group to a cluster MM bond. At T >130°C (M= Ru) and T >200°C (M=Os) cluster breakdown is observed, with formation of [M(CO) n (OSiM) 2 ] (n=2 and/or 3) species. When [Ru 3 (CO) 12 ] incorporated PVG is heated in air at T >250°C, decomposition of the cluster and formation of RuO 2 nanoparticles are observed. At 1200°C, collapse of the glass pores leads to the formation of a transparent silica glass/RuO 2 nanocomposite of particle average size 45 Å. tially pure silica with interconnecting pores of narrow size

Evaluation of porous silica glasses as insect pheromone dispensers

“…18,22 The capillarity of the pheromone molecules is enhanced during evaporation of the highly volatile solvent. These facts, added to the small amount of pheromone employed in each incorporation procedure, make us consider that almost all the initial pheromone was impregnated into PVG after complete evaporation of the solvent.…”

“…9). 12,13 The nanometric pores in PVG have been used to incorporate several compounds (conducting polymers, [14][15][16] oxides, [17][18][19] semiconductors, 20 amorphous carbon, 21 and carbon nanotubes 22 ), with the purpose of obtaining novel functional nanocomposite materials.…”

“…9). 12,13 The nanometric pores in PVG have been used to incorporate several compounds (conducting polymers, 14-16 oxides, [17][18][19] semiconductors, 20 amorphous carbon, 21 and carbon nanotubes 22 ), with the purpose of obtaining novel functional nanocomposite materials.The objective of this work was to demonstrate the feasibility of using PVG as a pheromone dispenser, and, to do so, PVG was impregnated with different pheromones. The assays included the characterization of the impregnated-PVG, the study of the pheromone release ratios under laboratory conditions and the practical application in two different cropping areas.…”

Sol–gel processing of a bimetallic alkoxide precursor confined in a porous glass matrix: A route to novel glass/metal oxide nanocomposites

“…In the last few years our research group has used PVG as a substrate for the growth of carbon nanotubes [20] and as a glass matrix to several nanocomposites with different materials: oxides [21], conducting and insulating polymers [22][23][24][25], carbon [25] and organometallic compounds [21,26,27], among others.…”

Properties of [Pd2X2(dppm)2] (X = Cl, SnCl3, dppm = Bis(diphenylphosphino)methane) complexes on porous vycor glass

“…[3][4][5][6][7] In this area, a number of papers describe the immobilization of carbonyl complexes of iron [3][4][5][6][7] and ruthenium [8][9][10] onto porous glasses, since these complexes are good precursors to metallic or oxide particles via thermal and photochemical decomposition.…”