TY - JOUR
T1 - Photochemistry of Iron and Ruthenium Carbonyl Complexes
T2 - Evidence for Light-Induced Loss of Carbon Monoxide and Reductive Elimination of Triethylsilane from cis-mer-HM(SiEt3)(CO)3(PPh3)
AU - Liu, David K.
AU - Brinkley, Cynthia G.
AU - Wrighton, Mark S.
PY - 1984/4
Y1 - 1984/4
N2 - The near-UV photochemistry of M(CO)4PPh3 and HM(SiEt3) (CO)3(PPh3) (M = Fe, Ru) has been investigated. The HM(SiEt3)(CO)3(PPh3) complexes have a meridional structure with the H cis to both PPh3 and the SiEt3 and are referred to as the cis-mer isomer. In low-temperature (~100 K) rigid organic glasses the M(CO)4PPh3 undergoes dissociative loss of CO to form the 16-electron M(CO)3PPh3, M-(CO)3(PPh3)(2-MeTHF), M(CO)3(PPh3)(l-C5H10), or cis-mer- and fac-HM(SiEt3)(CO)3(PPh3) complex when the organic glass is an alkane, 2-MeTHF, 1-C6H10, or Et3SiH, respectively. The fac-HM(SiEt3) (CO)3(PPh3) complexes undergo thermal isomerization to the cis-mer isomer upon warmup to 298 K. Near-UV excitation of cis-mer-HM(SiEt3) (CO)3(PPh3) at ~100 K in an organic glass gives evidence for both the loss of CO and reductive elimination of Et3SiH. Photochemistry of the complexes at 298 K in fluid solution accords well with photoreactions observed at ~100 K in rigid media. Irradiation of cis-mer-HM(SiEt3)(CO)3(PPh3) in a hydrocarbon solution of Ph3SiH at 298 K results in the formation of cis-mer-HM(SiPh3) (CO)3(PPh3) and Et3SiH with a 313-nm quantum yield of ~0.6. The process is photochemically reversed if the cismer-HM(SiPh3)(CO)3(PPh3) is irradiated in the presence of excess Et3SiH. Irradiation of cis-mer-HM-(SiEt3)(CO)3(PPh3) in a hydrocarbon solution at 298 K in the presence of 13CO yields both 13CO-enriched M(CO)4PPh3 and 13CO-enriched cis-mer-HM(SiEt3)(CO)3(PPh3). Irradiation of cis-mer-HM(SiR3)-(CO)3(PPh3) (R = OMe, OE3) or cis-mer-HRu(SiMeCl2)(CO)3(PPh3) at 298 Kin the presence of Et3SiH yields cis-mer-HM(SiEt3)(CO)3(PPh3), establishing the light-induced reductive elimination of R3SiH to occur for a wide range of R groups for these complexes.
AB - The near-UV photochemistry of M(CO)4PPh3 and HM(SiEt3) (CO)3(PPh3) (M = Fe, Ru) has been investigated. The HM(SiEt3)(CO)3(PPh3) complexes have a meridional structure with the H cis to both PPh3 and the SiEt3 and are referred to as the cis-mer isomer. In low-temperature (~100 K) rigid organic glasses the M(CO)4PPh3 undergoes dissociative loss of CO to form the 16-electron M(CO)3PPh3, M-(CO)3(PPh3)(2-MeTHF), M(CO)3(PPh3)(l-C5H10), or cis-mer- and fac-HM(SiEt3)(CO)3(PPh3) complex when the organic glass is an alkane, 2-MeTHF, 1-C6H10, or Et3SiH, respectively. The fac-HM(SiEt3) (CO)3(PPh3) complexes undergo thermal isomerization to the cis-mer isomer upon warmup to 298 K. Near-UV excitation of cis-mer-HM(SiEt3) (CO)3(PPh3) at ~100 K in an organic glass gives evidence for both the loss of CO and reductive elimination of Et3SiH. Photochemistry of the complexes at 298 K in fluid solution accords well with photoreactions observed at ~100 K in rigid media. Irradiation of cis-mer-HM(SiEt3)(CO)3(PPh3) in a hydrocarbon solution of Ph3SiH at 298 K results in the formation of cis-mer-HM(SiPh3) (CO)3(PPh3) and Et3SiH with a 313-nm quantum yield of ~0.6. The process is photochemically reversed if the cismer-HM(SiPh3)(CO)3(PPh3) is irradiated in the presence of excess Et3SiH. Irradiation of cis-mer-HM-(SiEt3)(CO)3(PPh3) in a hydrocarbon solution at 298 K in the presence of 13CO yields both 13CO-enriched M(CO)4PPh3 and 13CO-enriched cis-mer-HM(SiEt3)(CO)3(PPh3). Irradiation of cis-mer-HM(SiR3)-(CO)3(PPh3) (R = OMe, OE3) or cis-mer-HRu(SiMeCl2)(CO)3(PPh3) at 298 Kin the presence of Et3SiH yields cis-mer-HM(SiEt3)(CO)3(PPh3), establishing the light-induced reductive elimination of R3SiH to occur for a wide range of R groups for these complexes.
UR - https://www.scopus.com/pages/publications/0041033107
U2 - 10.1021/om00088a001
DO - 10.1021/om00088a001
M3 - Article
AN - SCOPUS:0041033107
SN - 0276-7333
VL - 3
SP - 1449
EP - 1457
JO - Organometallics
JF - Organometallics
IS - 10
ER -