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Diode-laser spectrum of isotopic carbonyl sulfide OC34S in the region of 847 cm−1
JOURNAL
OF MOLECULAR
SPECTROSCOPY
123, 14-25 (1987)
Diode-Laser Spectrum of Isotopic Carbonyl Sulfide 0C34S in the Region of 847 cm-’ GHISLAIN BLANQUET,F%I?DI?RICDERIE, AND JACQUES WALRAND Laboratoire de Spectroscopic Mol&daire, Fact&b Universitaires Notre-Dame de la Paix, Rue de Bruxelies, 61, B-5000-Namur, Belgium
The Y, band of OC% and its associated hot bands have been measured in the wavenumber range 800-880cm-’ using an enriched sample and a diode-laser spectrometer. Seven bands were assigned to ‘60’2C34Sand three bands to ‘60’2C36S,‘60’3C34S,and ‘sO’2C34Sisotopic species. 0 1987 Academic Press. Inc. I. INTRODUCTION Several authors have studied the spectrum of carbonyl sulfide (OCS) in the microwave and infrared regions. A list of references is found in Jolma et al. (I). Recently, in our laboratory new wavenumber measurements were made with a diode-laser spectrometer in the region of the fundamental v1 for the isotopic form enriched in 34S. Our purpose was to give accurate vibrational and rotational constants to complement previous results. II. EXPERIMENTAL DETAILS
The rovibrational spectra of OCS enriched in 34Swere measured in the region 800880 cm-’ with a tunable diode-laser (TDL) spectrometer. This apparatus has been described in detail in Refs. (2, 3). The absorption cell used in the present work is a multipass White-type cell with 1 m between mirrors. The absorption path length chosen was 52 m. The sample from Isotec-Ohio was enriched in 34S at 90% and the pressure used was usually 0.05 and 0.3 mbar for high-J values. At such low pressure, the pressure broadening of the lines was negligible, so the resolution is given by the Doppler width of the observed lines (N 1.35 X 10e3 cm-‘). The wavenumbers of the observed lines were calibrated by using Maki’s data (4)’ for the vl fundamental band of OCS. The relative calibration of the absorption lines is obtained with a Fabry-Perot etalon with a free range of 0.02985 1 cm-‘. In a previous paper (5), the absolute precision of our wavenumber measurements was estimated to be 0.00 1 cm-‘. A portion of the recorded spectrum near 860 cm-’ is shown in Fig. 1. III. EXPERIMENTAL RESULTS AND ANALYSIS The investigated region, 800-880 cm-‘, was covered with three Pb-Sn-Te diodes. One hundred and seven spectra with a mean range of 0.4 cm-’ were recorded and ’ A. G. Maki, private communication, 0022-2852187 $3.00 Copyright 0
1987 by Academic Press, Inc.
AU rights of reproduction in any form resewed.
1983. 14
DIODE-LASER SPECTRUM
I
-r
I
11
I
I I
15
OF OC%
I
I
II
III
IIIII
3
FICHIER: 229805 DIODE: 4 TEMP
:
1.0624 COURANT: i
I1
6259
DIAL
:
178 RUN ImA)
:
170
2
AEFER : OCS MOLECULE ocs
34
1
FREQUENCE: 859.7747
‘j
, /’ , , j(‘)( , , , ,‘I, / / / , , , ,’ , /
, , ,I ; , I, ,I / ) I, I, j
FIG. 1. Example of a treated spectrum: (1) Spectrum of OC3“S. (2) Smoothed etalon fringes. (3) Reference spectrum (OCS) with true profile.
more than 1500 lines measured. Almost all the lines were assigned to the transitions given in Table I. The remaining lines belong to transitions of normal isotopic species; these lines are not reported here. The identification of the bands and the assignment TABLE I Statistics for the Measured OCS Bands
16
BLANQUET, DERIE, AND WALRAND TABLE II Wavenumbers (cm-‘) for ‘60’2C%3 Transitions
-6 7
66 -66 c,
DIODE-LASER SPECTRUM OF 0C34S TABLE III Wavenumbers (cm-‘) for ‘60’2CwS Transitions
17
18
BLANQUET, DERIE, AND WALRAND TABLE IV Wavenumbers (cm-‘) for ‘60’2C’4STransitions
* -2 3
-7 8
-44
-2 -:: 4,
DIODE-LASER
TABLE
SPECTRUM
19
OF 0C”S
IV-Continued
of J quantum numbers were performed with the help of microwave data and also constants calculated by Fayt2 Loomis-Wood diagrams were very helpful in extending the assignment especially to lines belonging to very weak transitions. Approximately 95% of the measured lines were identified. Tables II-VIII list the observed wavenumbers of the assigned lines and also the differences between the calculated and the observed values. The diodes used cover practically the entire region studied except for small gaps in frequency where no laser modes were available. This explains most of the missing J values in the tables. The wavenumbers of the v, lines of OC34S have been given by Jolma et al. (6) and are not presented here. For the analysis of the transitions, we used a least-squares program based on the relation T”=G”+B”[J(J+
l)-Z’]k($qvJ(J+
1)~D”[J(J+
1)-12]2~(f)qj~J2(J+
1)’
(1)
where G, is the vibrational term, B, is the rotational constant, D, is the centrifugal *J. G. Lahaye,
R. Vandenhaute,
and A. Fayt, private communication,
1986.
20
BLANQUET,
DERIE, AND
WALRAND
TABLE V Wavenumbers (cm-‘) for OCS Transitions
0.0003 -0.000,
0.0002 0.000, 0.0006
distortion constant, and the I-doubling constants qvand qtiare the differences between the B and D constants for the component levels of the 1 doublets. In accordance with the convention of Brown el al. (7) the positive sign applies to theflevels and the negative sign to the e levels. The band center of the observed transition is given by
The rovibrational parameters v. , A B, and AD were determined for the fundamental zq and associated hot bands of 0C34S and are listed in Table IX. The rovibrational constants derived from the fits of other isotopic bands are presented in Table X. For this analysis, the rotational constants B” and D” of the molecule in the lower state
DIODE-LASER
SPECTRUM OF OC34S TABLE VI
Wavenumbers (cm-‘) for “O’%“S Transitions
4; ‘2 ‘3 “
‘5 ‘6 ‘7 :: 50 ::
21
22
BLANQUET,
DERIE, AND WALRAND TABLE VII
Wavenumbers (cm-‘)
have been
for ‘60’2C”STransitions
constrained to values obtained previously by various authors from microwave and heterodyne measurements (see footnotes to tables). In these tables, the constants B, AB, and 0, AD are given respectively in 10e5 and lo-* cm-‘. The effect of the higher order distortion constant (-I&) was found to be negligible in the fitting of experimental data. This is due to the fact that not very high J values have been observed and actually the H contribution is included in Beff and Deff constants. For the + transition, only a few lines have been measured, explaining the relatively poor precision of the analysis.
DIODE-LASER SPECTRUM OF 0C34S TABLE VIII Wavenumbers (cm-‘) for OCS Transitions
23
24
BLANQUET, DERIE, AND WALRAND TABLE IX Rovibrational Constants (cm-‘) Determined for Carbonyl Sulfide ‘60’2C34S Transition
El"(10-5&')
vo(cm -1)
lo”o-oo”o
a47.739319
a
F lllo-oooo 20°0-OOOO
6D(lo-acm-')
19789.8034b
-5a.9a77
4.1405b
0.07909
19a34.3754b
-53.564'
4.2099b
0.1212'4
F
F
E
la
i9ai4.1321b
-54.9919
4.196ab
0.1044
a41.0va412
19730.8073'
-60.143 10
4.2186'
0.0816 la
a34.a4536'4
19759.1025'
-56.272
4.2592'
0.109364
197a0.ai02c
-54.aa321
4.3009=
0.1177
f9a5a.4092d
-50.571'9
5.0312d
0.2944
E 1220-0220
D"(l0-acm-')
a41.1066oa E
21'0-11'0
bB(l0-5cn-')
15
834.96808
23
20
51 43
19a55.4092d
-50.592
4.2900d
0.11204a
12°0-0200
a34.5i03020
,9a51.2709d
-51.746 22
3.5014d
-0.0612 46
1330-0330
829.24178 27
19892.2222'
-47.339952
4.60820d
0.2208 187
a The standard deviation in the last digit. b From Jolma et al. (I). ’ From Wells et al. (8). d From Tanaka et al. (9).
For OC34S, the comparison with levels reported in the literature is given in Table XI and it shows a good agreement. Since previous values were obtained by very precise methods, such as heterodyne techniques and Fourier transform spectroscopy, the agreement confirms the good precision of our measurements. For 0C34S, our results have already been included by Fayt* in his general rovibrational analysis and the values calculated by Fayt are very close to our experimental results. TABLE X Rovibrational Constants (cm-‘) Determined for ‘6012C33S,‘6012C36S,‘60’3C34S,and ‘sO’2C3% Isotopic
form
16012C33S
Transition
vo(cm -I)
a53.2007a(11)a
loOo-OOOO F
B"u0-5cm-'~
6Ex10-5cm-'>
D*~uO-acm-'l
6D(10-8cm-')
20030.2446b
-59.740(14,
4.23a7b
0.0822(28)
20075.4674b
-53.958(20)
4.3134b
0.1501~62~
846.42611~11~
11'0-OOOO
20054.7533b
-55.490(21)
4.2999b
0.1259(62)
20°0-lo00
846.36622(19)
19970.5119b
-60.902(40)
4.3234b
0.0820(150)
16012C36S
loOo-OOOO
837.56641(15)
l9345.6903'
-57.575<14)
3.9654'
0.0709(27)
16013C34S
~o"o-ooOo
843.1312(15)
19719.4191=
-58.646<13,
4.1291'
o.oaa4<21)
la012t34S
loOo-ooOo
826.65071(33)
18546.0543C
-52.695(54)
3.5954C
0.0450~173~
E
The standard deviation in the last digit is given in parentheses following each value. b Burenin et al. (10). ’ Burenin et al. (11). '
DIODE-LASER
SPECTRUM
OF 0C34S
25
TABLE XI
Comparison with Previously Observed Values TRANSITION
lo%oo"
11'0-01'0
20%lODO
CONSTANTa
JKHb
UPMC
This
work
yo
847.73932
847.73936
8’
19730.818
19730.807
19730.816
D’
4.2228
4.2186
4.2195
yo
a41.10678
841.10660
E’F
19780.810
~9780.811
B’E
19759.102
19759.141
D’F
4.3010
4.3311
D’E
4.2592
4.3010
a41 .oi751
841.01784
“Q 8’ D’
au.73931
19670.692
19670.664
4.2186
4.2195
* Band center (cm-‘), upper level constant 3’ (IO-’ cm-‘), upper level constant D’ (IO-’ cm-‘) b Jolma, Kauppinen, and Homeman (6). ’ Wells, Petersen, and Maki (8).
ACKNOWLEDGMENTS
The authors thank Dr. M. Dang-Nhu for suggesting valuable modifications in our analysis program and Dr. A. Fayt for helpful discussions and providing his calculations prior to publication. RECEIVED:
July 2 1, 1986 REFERENCES
1. K. JOLMA,V. M. HORNEMAN,AND J. KAUPPINEN,J. Mol. Specfrosc. 113, 167-174 (1985). 2. P. HERBIN,G. BLANQUET,J. WALRAND, AND C. P. COURTOY,J. Mol. Spectrosc. 104,262-270 (1984). 3. G. BLANQUETAND J. WALRAND, Computer Enhanc. Spectrosc. 2, 135-140 (1984). 4. J. S. WELLS, F. R. PETERSEN,A. G. MAKI, AND D. J. SUKLE,Appl. Optics 20, 1676-1684 (198 I). 5. E. BAETEN,G. BLANQUET,J. WALRAND, AND C. P. COURTOY,Canad. J. Phys. 62,1286-1292 (1984). 6. K. JOLMA,J. KAUPPINEN,AND V. M. HORNEMAN,J. Mol. Spectrosc. 101, 300-305 (1983). 7. J. M. BROWN, J. T. HOUGEN, K. P. HUBER, J. W. C. JOHNS,I. KOPP, H. LEFEBVRE-BRION, A. J. MERER,D. A. RAMSAY,J. ROSTAS,AND R. N. ZARE, J. Mol. Spectrosc. 55, 500-503 (1975). 8. J. S. WELLS,F. R. PETERSEN,AND A. G. MAKI, J. Mol. Spectrosc. 98,404-412 (1983). 9. K. TANAKA, H. ITO, K. HARADA, ANDT. TANAKA, J. Chem. Phys. 80,5893-5905 (1984). 10. A. V. BURENIN, A. N. VAL’DOV, E. N. KARYAKIN, A. F. KRUPNOV, AND S. M. SHAPIN, J. Mol. Speclrosc. 87, 3 12-3 15 ( I98 I). II. A. V. BURENIN, E. N. KARYAKIN, A. F. KRUPNOV, S. M. SHAPIN, AND A. N. VAL’DOV, J. Mol. Spectrosc. 85, l-7 ( 198 I ).
OF MOLECULAR
SPECTROSCOPY
123, 14-25 (1987)
Diode-Laser Spectrum of Isotopic Carbonyl Sulfide 0C34S in the Region of 847 cm-’ GHISLAIN BLANQUET,F%I?DI?RICDERIE, AND JACQUES WALRAND Laboratoire de Spectroscopic Mol&daire, Fact&b Universitaires Notre-Dame de la Paix, Rue de Bruxelies, 61, B-5000-Namur, Belgium
The Y, band of OC% and its associated hot bands have been measured in the wavenumber range 800-880cm-’ using an enriched sample and a diode-laser spectrometer. Seven bands were assigned to ‘60’2C34Sand three bands to ‘60’2C36S,‘60’3C34S,and ‘sO’2C34Sisotopic species. 0 1987 Academic Press. Inc. I. INTRODUCTION Several authors have studied the spectrum of carbonyl sulfide (OCS) in the microwave and infrared regions. A list of references is found in Jolma et al. (I). Recently, in our laboratory new wavenumber measurements were made with a diode-laser spectrometer in the region of the fundamental v1 for the isotopic form enriched in 34S. Our purpose was to give accurate vibrational and rotational constants to complement previous results. II. EXPERIMENTAL DETAILS
The rovibrational spectra of OCS enriched in 34Swere measured in the region 800880 cm-’ with a tunable diode-laser (TDL) spectrometer. This apparatus has been described in detail in Refs. (2, 3). The absorption cell used in the present work is a multipass White-type cell with 1 m between mirrors. The absorption path length chosen was 52 m. The sample from Isotec-Ohio was enriched in 34S at 90% and the pressure used was usually 0.05 and 0.3 mbar for high-J values. At such low pressure, the pressure broadening of the lines was negligible, so the resolution is given by the Doppler width of the observed lines (N 1.35 X 10e3 cm-‘). The wavenumbers of the observed lines were calibrated by using Maki’s data (4)’ for the vl fundamental band of OCS. The relative calibration of the absorption lines is obtained with a Fabry-Perot etalon with a free range of 0.02985 1 cm-‘. In a previous paper (5), the absolute precision of our wavenumber measurements was estimated to be 0.00 1 cm-‘. A portion of the recorded spectrum near 860 cm-’ is shown in Fig. 1. III. EXPERIMENTAL RESULTS AND ANALYSIS The investigated region, 800-880 cm-‘, was covered with three Pb-Sn-Te diodes. One hundred and seven spectra with a mean range of 0.4 cm-’ were recorded and ’ A. G. Maki, private communication, 0022-2852187 $3.00 Copyright 0
1987 by Academic Press, Inc.
AU rights of reproduction in any form resewed.
1983. 14
DIODE-LASER SPECTRUM
I
-r
I
11
I
I I
15
OF OC%
I
I
II
III
IIIII
3
FICHIER: 229805 DIODE: 4 TEMP
:
1.0624 COURANT: i
I1
6259
DIAL
:
178 RUN ImA)
:
170
2
AEFER : OCS MOLECULE ocs
34
1
FREQUENCE: 859.7747
‘j
, /’ , , j(‘)( , , , ,‘I, / / / , , , ,’ , /
, , ,I ; , I, ,I / ) I, I, j
FIG. 1. Example of a treated spectrum: (1) Spectrum of OC3“S. (2) Smoothed etalon fringes. (3) Reference spectrum (OCS) with true profile.
more than 1500 lines measured. Almost all the lines were assigned to the transitions given in Table I. The remaining lines belong to transitions of normal isotopic species; these lines are not reported here. The identification of the bands and the assignment TABLE I Statistics for the Measured OCS Bands
16
BLANQUET, DERIE, AND WALRAND TABLE II Wavenumbers (cm-‘) for ‘60’2C%3 Transitions
-6 7
66 -66 c,
DIODE-LASER SPECTRUM OF 0C34S TABLE III Wavenumbers (cm-‘) for ‘60’2CwS Transitions
17
18
BLANQUET, DERIE, AND WALRAND TABLE IV Wavenumbers (cm-‘) for ‘60’2C’4STransitions
* -2 3
-7 8
-44
-2 -:: 4,
DIODE-LASER
TABLE
SPECTRUM
19
OF 0C”S
IV-Continued
of J quantum numbers were performed with the help of microwave data and also constants calculated by Fayt2 Loomis-Wood diagrams were very helpful in extending the assignment especially to lines belonging to very weak transitions. Approximately 95% of the measured lines were identified. Tables II-VIII list the observed wavenumbers of the assigned lines and also the differences between the calculated and the observed values. The diodes used cover practically the entire region studied except for small gaps in frequency where no laser modes were available. This explains most of the missing J values in the tables. The wavenumbers of the v, lines of OC34S have been given by Jolma et al. (6) and are not presented here. For the analysis of the transitions, we used a least-squares program based on the relation T”=G”+B”[J(J+
l)-Z’]k($qvJ(J+
1)~D”[J(J+
1)-12]2~(f)qj~J2(J+
1)’
(1)
where G, is the vibrational term, B, is the rotational constant, D, is the centrifugal *J. G. Lahaye,
R. Vandenhaute,
and A. Fayt, private communication,
1986.
20
BLANQUET,
DERIE, AND
WALRAND
TABLE V Wavenumbers (cm-‘) for OCS Transitions
0.0003 -0.000,
0.0002 0.000, 0.0006
distortion constant, and the I-doubling constants qvand qtiare the differences between the B and D constants for the component levels of the 1 doublets. In accordance with the convention of Brown el al. (7) the positive sign applies to theflevels and the negative sign to the e levels. The band center of the observed transition is given by
The rovibrational parameters v. , A B, and AD were determined for the fundamental zq and associated hot bands of 0C34S and are listed in Table IX. The rovibrational constants derived from the fits of other isotopic bands are presented in Table X. For this analysis, the rotational constants B” and D” of the molecule in the lower state
DIODE-LASER
SPECTRUM OF OC34S TABLE VI
Wavenumbers (cm-‘) for “O’%“S Transitions
4; ‘2 ‘3 “
‘5 ‘6 ‘7 :: 50 ::
21
22
BLANQUET,
DERIE, AND WALRAND TABLE VII
Wavenumbers (cm-‘)
have been
for ‘60’2C”STransitions
constrained to values obtained previously by various authors from microwave and heterodyne measurements (see footnotes to tables). In these tables, the constants B, AB, and 0, AD are given respectively in 10e5 and lo-* cm-‘. The effect of the higher order distortion constant (-I&) was found to be negligible in the fitting of experimental data. This is due to the fact that not very high J values have been observed and actually the H contribution is included in Beff and Deff constants. For the + transition, only a few lines have been measured, explaining the relatively poor precision of the analysis.
DIODE-LASER SPECTRUM OF 0C34S TABLE VIII Wavenumbers (cm-‘) for OCS Transitions
23
24
BLANQUET, DERIE, AND WALRAND TABLE IX Rovibrational Constants (cm-‘) Determined for Carbonyl Sulfide ‘60’2C34S Transition
El"(10-5&')
vo(cm -1)
lo”o-oo”o
a47.739319
a
F lllo-oooo 20°0-OOOO
6D(lo-acm-')
19789.8034b
-5a.9a77
4.1405b
0.07909
19a34.3754b
-53.564'
4.2099b
0.1212'4
F
F
E
la
i9ai4.1321b
-54.9919
4.196ab
0.1044
a41.0va412
19730.8073'
-60.143 10
4.2186'
0.0816 la
a34.a4536'4
19759.1025'
-56.272
4.2592'
0.109364
197a0.ai02c
-54.aa321
4.3009=
0.1177
f9a5a.4092d
-50.571'9
5.0312d
0.2944
E 1220-0220
D"(l0-acm-')
a41.1066oa E
21'0-11'0
bB(l0-5cn-')
15
834.96808
23
20
51 43
19a55.4092d
-50.592
4.2900d
0.11204a
12°0-0200
a34.5i03020
,9a51.2709d
-51.746 22
3.5014d
-0.0612 46
1330-0330
829.24178 27
19892.2222'
-47.339952
4.60820d
0.2208 187
a The standard deviation in the last digit. b From Jolma et al. (I). ’ From Wells et al. (8). d From Tanaka et al. (9).
For OC34S, the comparison with levels reported in the literature is given in Table XI and it shows a good agreement. Since previous values were obtained by very precise methods, such as heterodyne techniques and Fourier transform spectroscopy, the agreement confirms the good precision of our measurements. For 0C34S, our results have already been included by Fayt* in his general rovibrational analysis and the values calculated by Fayt are very close to our experimental results. TABLE X Rovibrational Constants (cm-‘) Determined for ‘6012C33S,‘6012C36S,‘60’3C34S,and ‘sO’2C3% Isotopic
form
16012C33S
Transition
vo(cm -I)
a53.2007a(11)a
loOo-OOOO F
B"u0-5cm-'~
6Ex10-5cm-'>
D*~uO-acm-'l
6D(10-8cm-')
20030.2446b
-59.740(14,
4.23a7b
0.0822(28)
20075.4674b
-53.958(20)
4.3134b
0.1501~62~
846.42611~11~
11'0-OOOO
20054.7533b
-55.490(21)
4.2999b
0.1259(62)
20°0-lo00
846.36622(19)
19970.5119b
-60.902(40)
4.3234b
0.0820(150)
16012C36S
loOo-OOOO
837.56641(15)
l9345.6903'
-57.575<14)
3.9654'
0.0709(27)
16013C34S
~o"o-ooOo
843.1312(15)
19719.4191=
-58.646<13,
4.1291'
o.oaa4<21)
la012t34S
loOo-ooOo
826.65071(33)
18546.0543C
-52.695(54)
3.5954C
0.0450~173~
E
The standard deviation in the last digit is given in parentheses following each value. b Burenin et al. (10). ’ Burenin et al. (11). '
DIODE-LASER
SPECTRUM
OF 0C34S
25
TABLE XI
Comparison with Previously Observed Values TRANSITION
lo%oo"
11'0-01'0
20%lODO
CONSTANTa
JKHb
UPMC
This
work
yo
847.73932
847.73936
8’
19730.818
19730.807
19730.816
D’
4.2228
4.2186
4.2195
yo
a41.10678
841.10660
E’F
19780.810
~9780.811
B’E
19759.102
19759.141
D’F
4.3010
4.3311
D’E
4.2592
4.3010
a41 .oi751
841.01784
“Q 8’ D’
au.73931
19670.692
19670.664
4.2186
4.2195
* Band center (cm-‘), upper level constant 3’ (IO-’ cm-‘), upper level constant D’ (IO-’ cm-‘) b Jolma, Kauppinen, and Homeman (6). ’ Wells, Petersen, and Maki (8).
ACKNOWLEDGMENTS
The authors thank Dr. M. Dang-Nhu for suggesting valuable modifications in our analysis program and Dr. A. Fayt for helpful discussions and providing his calculations prior to publication. RECEIVED:
July 2 1, 1986 REFERENCES
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