TY - JOUR
T1 - Pulsed laser photodissociation of chromium hexacarbonyl at 308 nm
T2 - simultaneous monitoring of optical and acoustic emissions
AU - CHEUNG, Nai Ho
AU - Yeung, Edward S.
N1 - Funding Information:
One of us (NHC) would like to acknowledget he Iowa State University ExchangeV isitor Program for supporting his summer study-leave at ISU, Ames. The Ames Laboratory is operated for the US Department of Energy by Iowa State University under Contract No. W-7405-Eng-82. This work is supported by the Offtce of Basic Energy Sciences, Division of Chemical Sciences.
PY - 1992/1/31
Y1 - 1992/1/31
N2 - A novel, yet simple, acoustic technique was applied to measure the molar number of fragments formed in the XeCl laser-induced gas-phase photodissociation of Cr(CO)6. The bluish-green Cr emission was also monitored and correlated with the acoustic signal. At 0.16 Torr of hexacarbonyl and for fluences below ≈ 25 mJ/cm2, the optical signal varied as the cube of the laser fluence, in agreement with the model that highly excited Cr atoms were produced by three-photon processes. The acoustic signal y (mV) varied with fluence F (mJ/cm2) as y = 1.77F + 0.15F2, consistent with the model that most fragments were formed via two sequential single-photon processes. Both optical and acoustic signals showed onset of saturation at ≈ 25 mJ/cm2, suggesting that single-photon photolysis was the primary Cr(CO)6 depletion process. Quite expectedly, with a constant fluence of ≈ 20 mJ/cm2 and varying hexacarbonyl pressure, the optical and acoustic signals were linearly correlated.
AB - A novel, yet simple, acoustic technique was applied to measure the molar number of fragments formed in the XeCl laser-induced gas-phase photodissociation of Cr(CO)6. The bluish-green Cr emission was also monitored and correlated with the acoustic signal. At 0.16 Torr of hexacarbonyl and for fluences below ≈ 25 mJ/cm2, the optical signal varied as the cube of the laser fluence, in agreement with the model that highly excited Cr atoms were produced by three-photon processes. The acoustic signal y (mV) varied with fluence F (mJ/cm2) as y = 1.77F + 0.15F2, consistent with the model that most fragments were formed via two sequential single-photon processes. Both optical and acoustic signals showed onset of saturation at ≈ 25 mJ/cm2, suggesting that single-photon photolysis was the primary Cr(CO)6 depletion process. Quite expectedly, with a constant fluence of ≈ 20 mJ/cm2 and varying hexacarbonyl pressure, the optical and acoustic signals were linearly correlated.
UR - http://www.scopus.com/inward/record.url?scp=44049118959&partnerID=8YFLogxK
U2 - 10.1016/0009-2614(92)85117-S
DO - 10.1016/0009-2614(92)85117-S
M3 - Journal article
AN - SCOPUS:44049118959
SN - 0009-2614
VL - 189
SP - 164
EP - 170
JO - Chemical Physics Letters
JF - Chemical Physics Letters
IS - 2
ER -