TY - JOUR
T1 - Characterization and Photochemistry of Surface-Confined Mononuclear and Trinuclear Phosphine/carbonyl Complexes of Ruthenium(0)
AU - Liu, David K.
AU - Wrighton, Mark S.
AU - Mckay, Dale R.
AU - Maciel, Gary E.
PY - 1984/6
Y1 - 1984/6
N2 - The characterization and photochemistry of [SiO2]-LRu(CO)4and [SiO2]-L3Ru3(CO)9are reported, where [SiO2]-represents high surface area (~400 m2/g) SiO2. Synthesis of [SiO2]-LRu(CO)4and [SiO2]-L3Ru3(CO)9is effected by reaction of Ru(CO)4(PPh2CH2CH2Si(OEt)3) or Ru3(CO)9(PPh2CH2CH2Si(OEt)3)3with a hydrocarbon suspension of [SiO2]-. Solid-state 13C, 29Si, and 31P CP/MAS NMR, FTIR, UV-vis photoacoustic spectroscopy, and elemental analyses establish the nature of the functionalized [SiO2]-. Typical coverage of -LRu(CO)4or -L3Ru3(CO)9is ∼ 10-10-10-11 mol/cm2. Photoexcitation (near-UV) of [SiG2]-LRu(CO)4suspended in hydrocarbon media results in a chemical reaction consistent with the 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 (~90 K). Near-UV irradiation of [SiO2]-LRu(CO)4at 298 K exposed to a gas gives chemistry consistent with dissociative loss of CO, also. Complete (>90%) exchange of CO for 13CO can be effected by irradiation under 1 atm of 13CO, as monitored by FTIR/photoacoustic spectroscopy. The photochemistry of [SiO2]-L3Ru3(CO)9involves metal-metal bond rupture; under 1 atm of CO in a solid/gas reaction or as a suspension in hydrocarbon solvent saturated with CO, [SiO2]-L3Ru3(C0)9yields [SiO2]-(LRu(CO)4)3. The surface-confined mononuclear species formed photochemically from the surface-confined trinuclear species are spectroscopically indistinguishable from the deliberately synthesized [SiO2]-LRu(CO)4. However, irradiation of [SiO2]-(LRu(CO)4)3leads to reassembly of the surface cluster, [SiO2]-L3Ru3(CO)9, whereas irradiation of [SiO2]-LRu(CO)4yields no surface cluster. For small P-donors, V, irradiation of [SiO2]-L3Ru3(CO)9yields [SiO2]-(LRu(CO)3L')3, whereas [SiO2]-LRu(CO)4yields [SiO2]-LRu(CO)3L' for large and small L'. Both [SiO2]-LRu(CO)4and [SiO2]-L3Ru3(CO)9yield gas-phase CO and CO2as products when irradiated while exposed to an O2-containing atmosphere.
AB - The characterization and photochemistry of [SiO2]-LRu(CO)4and [SiO2]-L3Ru3(CO)9are reported, where [SiO2]-represents high surface area (~400 m2/g) SiO2. Synthesis of [SiO2]-LRu(CO)4and [SiO2]-L3Ru3(CO)9is effected by reaction of Ru(CO)4(PPh2CH2CH2Si(OEt)3) or Ru3(CO)9(PPh2CH2CH2Si(OEt)3)3with a hydrocarbon suspension of [SiO2]-. Solid-state 13C, 29Si, and 31P CP/MAS NMR, FTIR, UV-vis photoacoustic spectroscopy, and elemental analyses establish the nature of the functionalized [SiO2]-. Typical coverage of -LRu(CO)4or -L3Ru3(CO)9is ∼ 10-10-10-11 mol/cm2. Photoexcitation (near-UV) of [SiG2]-LRu(CO)4suspended in hydrocarbon media results in a chemical reaction consistent with the 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 (~90 K). Near-UV irradiation of [SiO2]-LRu(CO)4at 298 K exposed to a gas gives chemistry consistent with dissociative loss of CO, also. Complete (>90%) exchange of CO for 13CO can be effected by irradiation under 1 atm of 13CO, as monitored by FTIR/photoacoustic spectroscopy. The photochemistry of [SiO2]-L3Ru3(CO)9involves metal-metal bond rupture; under 1 atm of CO in a solid/gas reaction or as a suspension in hydrocarbon solvent saturated with CO, [SiO2]-L3Ru3(C0)9yields [SiO2]-(LRu(CO)4)3. The surface-confined mononuclear species formed photochemically from the surface-confined trinuclear species are spectroscopically indistinguishable from the deliberately synthesized [SiO2]-LRu(CO)4. However, irradiation of [SiO2]-(LRu(CO)4)3leads to reassembly of the surface cluster, [SiO2]-L3Ru3(CO)9, whereas irradiation of [SiO2]-LRu(CO)4yields no surface cluster. For small P-donors, V, irradiation of [SiO2]-L3Ru3(CO)9yields [SiO2]-(LRu(CO)3L')3, whereas [SiO2]-LRu(CO)4yields [SiO2]-LRu(CO)3L' for large and small L'. Both [SiO2]-LRu(CO)4and [SiO2]-L3Ru3(CO)9yield gas-phase CO and CO2as products when irradiated while exposed to an O2-containing atmosphere.
UR - https://www.scopus.com/pages/publications/33845471225
U2 - 10.1021/ic00170a019
DO - 10.1021/ic00170a019
M3 - Article
AN - SCOPUS:33845471225
SN - 0020-1669
VL - 23
SP - 212
EP - 220
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 2
ER -