Abstract
We have observed the infrared emission from the products of the 193 nm photolysis of diethyl ketone (3-pentanone) in comparison with acetone (2-propanone) using time-resolved Fourier transform spectroscopy. In the photolysis of diethyl ketone, two bands are apparent: The first, spanning the region 1950 to 2250 cm-1, is assigned to CO rovibrational transitions; the other band, spanning the region 2800 to 3400 cm-1 and not exhibiting resolved line structure, is assigned to the ethyl radical. Spectral simulations of the CO bands under conditions of minimal, but not negligible, relaxation produce a lower bound for the nascent CO rotational temperature of ∼2100 K. The CO vibrational population distribution varies slowly over the ∼80 μs time spanned by our experiment. Both the rotational and vibrational energies of CO exceed statistical partitioning in the dissociation of acetone. In comparison to the case of acetone, absolute energies in CO vibration and rotation decrease only modestly for diethyl ketone, corresponding to a dramatic increase in the excess above the statistically partitioned energies. Several simple dissociation models are compared to these results. None is fully satisfactory.
| Original language | English |
|---|---|
| Pages (from-to) | 6660-6668 |
| Number of pages | 9 |
| Journal | Journal of Chemical Physics |
| Volume | 102 |
| Issue number | 17 |
| Publication status | Published - 1995 |
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ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
Cite this
Studies of the 193 nm photolysis of diethyl ketone and acetone using time-resolved Fourier transform emission spectroscopy. / Hall, Gregory E.; Metzler, H. W.; Muckerman, James; Preses, Jack M.; Weston, Ralph E.
In: Journal of Chemical Physics, Vol. 102, No. 17, 1995, p. 6660-6668.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Studies of the 193 nm photolysis of diethyl ketone and acetone using time-resolved Fourier transform emission spectroscopy
AU - Hall, Gregory E.
AU - Metzler, H. W.
AU - Muckerman, James
AU - Preses, Jack M.
AU - Weston, Ralph E.
PY - 1995
Y1 - 1995
N2 - We have observed the infrared emission from the products of the 193 nm photolysis of diethyl ketone (3-pentanone) in comparison with acetone (2-propanone) using time-resolved Fourier transform spectroscopy. In the photolysis of diethyl ketone, two bands are apparent: The first, spanning the region 1950 to 2250 cm-1, is assigned to CO rovibrational transitions; the other band, spanning the region 2800 to 3400 cm-1 and not exhibiting resolved line structure, is assigned to the ethyl radical. Spectral simulations of the CO bands under conditions of minimal, but not negligible, relaxation produce a lower bound for the nascent CO rotational temperature of ∼2100 K. The CO vibrational population distribution varies slowly over the ∼80 μs time spanned by our experiment. Both the rotational and vibrational energies of CO exceed statistical partitioning in the dissociation of acetone. In comparison to the case of acetone, absolute energies in CO vibration and rotation decrease only modestly for diethyl ketone, corresponding to a dramatic increase in the excess above the statistically partitioned energies. Several simple dissociation models are compared to these results. None is fully satisfactory.
AB - We have observed the infrared emission from the products of the 193 nm photolysis of diethyl ketone (3-pentanone) in comparison with acetone (2-propanone) using time-resolved Fourier transform spectroscopy. In the photolysis of diethyl ketone, two bands are apparent: The first, spanning the region 1950 to 2250 cm-1, is assigned to CO rovibrational transitions; the other band, spanning the region 2800 to 3400 cm-1 and not exhibiting resolved line structure, is assigned to the ethyl radical. Spectral simulations of the CO bands under conditions of minimal, but not negligible, relaxation produce a lower bound for the nascent CO rotational temperature of ∼2100 K. The CO vibrational population distribution varies slowly over the ∼80 μs time spanned by our experiment. Both the rotational and vibrational energies of CO exceed statistical partitioning in the dissociation of acetone. In comparison to the case of acetone, absolute energies in CO vibration and rotation decrease only modestly for diethyl ketone, corresponding to a dramatic increase in the excess above the statistically partitioned energies. Several simple dissociation models are compared to these results. None is fully satisfactory.
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M3 - Article
VL - 102
SP - 6660
EP - 6668
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
SN - 0021-9606
IS - 17
ER -