Characterization and Photochemistry of Surface-Confined Mononuclear and Trinuclear Phosphine/Carbonyl Complexes of Ruthenium(0).
Abstract
The characterization and photochemistry of (SiO2)-LRu(CO)4 and (SiO2)-L3Ru3(CO)9 is reported where (SiO2)- represents high surface area (approx. 400 square meters/g) SiO2. Synthesis of the (SiO2)-LRu(CO)4 and (SiO2)-L3Ru3(CO)9 is effected by reaction of Ru(CO)4(PPh2CH2CH2Si(OEt)3) or Ru3(CO)9(PPh2CH2CH2Si(OEt)3)3 with a hydrocarbon suspension of (SiO2)-. Solid state 13C, (29)Si, and (31)p CP/MAS NMR, FTIR, uv-vis photoacoustic spectroscopy, and elemental analyses establish the nature of the functionalized (SiO2)-. Typical coverage of -LRu(CO)4 or -L3Ru3(CO)9 is approx. 10 to the the minus 10 - ten to the minus 11 mol/square meters. Photoexcitation (near-uv) of (SiO2)-LRu(CO)4 suspended in hydrocarbon media results in chemical reaction consistent with dissociative loss of CO to give a 16-valence electron, surface-confined species that reacts with 2-electron P-donors. The light-induced extrusion of CO can be effected and detected spectroscopically by chemical trapping in rigid media at low temperature (approx. 90 K). Near-uv irradiation of (SiO2)-LRu(CO)4 at 298 K exposed to a gas gives chemistry consistent with dissociative loss of CO, also. Complete (greater than 90%) exchange of CO for (13)CO can be effected by irradiation under 1 atm (13)CO as monitored by FTIR/photoacoustic spectroscopy. The photochemistry of (SiO2)-LeRu3(CO)9 involves metal-metal bond rupture; under 1 atm CO in a solid/gas reaction or as a suspension in hydrocarbon solvent saturated with CO the (SiO2)-L3Ru3(CO)9 yields (SiO2)-(LRu(CO)4)3.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 15, 1983
- Accession Number
- ADA130666
Entities
People
- Dale R. Mckay
- David K. Liu
- Gary E. Maciel
- Mark S. Wrighton
Organizations
- Massachusetts Institute of Technology