Browsing by Author "Ogilvie, JF"

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Detection of vibration-rotational band 5-0 of (CO)-C-12-O-16 X (1)Sigma(+) with cavity ringdown absorption near 0.96 mu m
(2005-09-08)
Chung, CY
;
Ogilvie, JF
;
Lee, YP
;
應用化學系
;
應用化學系分子科學碩博班
We have recorded extremely weak absorption in the overtone band 5-0 of (CO)-C-12-O-16 X (1)Sigma(+) near 0.96 mu m with cavity ringdown spectroscopy; the light source was a Raman-shifted dye laser pumped with a frequency doubled Nd:YAG laser. This band shows lines in branch P to be much more intense than corresponding lines in branch R, in contrast to all lower overtone bands v-0 (v = 1-4). This reversal in relative intensity is explained quantitatively in terms of a radial function for the electric dipolar moment of CO. We have estimated absorption line strengths for P-3-P-18 in band 5-0 of (CO)-C-12-O-16; these strengths are consistent with a pure vibrational matrix element (5 vertical bar p(x)vertical bar 0) = (3.6 +/- 0.3) x 10(-36) C m of the electric dipolar moment p(x), a Herman-Wallis coefficient C-0(5) of about -0.1, and a band strength of (5.1 +/- 1.3) x 10(-29) m at 293 K.
Intensities of line features in vibration-rotational bands 2-0 to 6-0 of (NO)-N-14-O-16 X-2 Pi(r) and experimental evaluation of a radial function for electric dipolar moment
(2006-01-01)
Lee, YP
;
Cheah, SL
;
Ogilvie, JF
;
應用化學系
;
應用化學系分子科學碩博班
We measured the strengths of individual line-like features, representing unresolved A doublets, in vibration-rotational bands 2-0 to 6-0 of (NO)-N-14-O-16 within each substate of electronic ground state X(2)Pi(1/2,3/2) in mid and near infrared regions. Analyses of these data to derive values of matrix element; for vibrational transitions enabled production of a radial function for electric dipolar moment, containing seven parameters, that satisfactorily reproduces the intensities of about 700 such features for vibrational states up to v = 6. (c) 2005 Elsevier B.V. All rights reserved.
Photolysis of oxalyl chloride (ClCO)(2) at 248 nm: Emission of CO(v '<= 3, J '<= 51) detected with time-resolved Fourier transform spectroscopy
(2003-04-10)
Wu, CY
;
Lee, YP
;
Ogilvie, JF
;
Wang, NS
;
應用化學系
Upon photolysis of oxalyl chloride at 248 nm, rotationally resolved emission of CO (v less than or equal to 3) in the spectral region 1900-2300 cm(-1) was detected with a step-scan time-resolved Fourier transform spectrometer under nearly collisionless conditions. Boltzmann-like rotational distributions of CO (v = 1 and 2) correspond to temperatures similar to2290 +/- 100 and 1910 +/- 130 K, respectively, with average rotational energy of 16 +/- 2 kJ mol 1; several lines of CO (v = 3) were also observed, but their weak intensity precludes quantitative analysis. The average vibrational energy of CO is estimated to be 10 +/- 3 kJ mol(-1) according to observed vibrational populations of v = 1 and 2 and that of v = 0 and 3 predicted with surprisal analysis. Combining the average internal energy of CO determined in this work and average translational energies of photofragments Cl, CO, and ClCO determined previously by Suits and co-workers, we derived a revised energy balance. We observed no emission of ClCO near 1880 cm(-1), indicating that ClCO (v(1) = 1) decomposes rapidly and that surviving ClCO has little vibrational excitation in the CO stretching mode. Most CO produced from decomposition of ClCO is in its vibrational ground state with small rotational excitation, undetectable with our technique.