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Rotational analysis of the 0-0 band of the b 0+ → X1 0+ system of 130Te80Se
JOURNAL
OF MOLECULAR
SPECTROSCOPY
136,2 18-221 ( 1989)
Rotational Analysis of the O-O Band of the b O+ + X1 O+ System of 130Te80Se’
The b 0+-X, O+, X, 1 band system of TeSe has been observed in emission in the near infrared using a, discharge flow system (1). In the present work the O-O band of the b 0+:X, O+ subsystem is recorded at high resolution using separated “@fe and 8oSe isotopes, and a rotational analysis is carried out. The experimental apparatus has been described in an earlier publication (2) and the conditions were similar to those given in Ref. (I). Isotopically enriched “@I’e(99.29%) and “Se (99.57%) were used and were obtained from Oak Ridge National Laboratories. The infrared chemiluminescence was focused on the entrance iris of a Bomem DA3.002 Fourier transform spectrometer and a spectrum was recorded in the region 7530 to 8800 cm-’ using a liquid nitrogen cooled germanium detector and a resolution of 0.02 cm-‘. The O-O band of the b 0+-X, O+ subsystem of ‘qesoSe consists of a simple P and R branch. Lines are observed up to J - 100; the lines in the R branch form a head at J - 40 and the lines with higher J values overlap those with lower J values and also the low-J lines of the P branch. As a result no clear zero gap is observed. The rotational numbering was determined by assuming that the ground state bond length lies close to the mean of the values for Tez and Sez (see below). The assignments are given in Table I. The frequencies of the lines were fitted by least squares to the usual quartic expression (3) and the molecular constants obtained are given in the lower part of Table II. The overall standard deviation of the fit was 0.003e, cm-’ but the stronger lines of the P branch which are free from overlapping are fitted to rlIO.001 cm-‘. The values of Bb, BE, Db, and 06 derived from the above numbers are given in the upper part of Table II together with the values for the bond lengths rb and r6. The values for D lie close to those calculated from the approximate Kratzer relation (3), Do - 4Bi/wZ where AGl,z is substituted for w, viz. 10’0’ = 1.02 cm-‘, lOgO” = 0.94 cm-‘. A few ground state bond lengths for related molecules are given in Table III. The values for the heteronuclear molecules lie close to the means of the values for the corresponding homonuclear molecules and provide the justification for adopting the present rotational numbering for TeSe. The intensity data are not sufficiently accurate to determine a rotational temperature but the overall distribution is consistent with a temperature of -3 10 K as has been found in related systems (2, 5, 6). The R-head of the b 0+-X, 1 subband is observed at 755 1.84 cm-’ but the intensity of the subband was insufficient to justify a rotational analysis. Nevertheless, we obtain a value for the Xz I-X, O+ separation, viz. 1233.49 cm-‘. This value differs from that given in the literature (7) by one vibrational quantum, indicating an error in the vibrational numbering in the earlier work. A stronger spectrum was obtained by us in the region 7300 to 9100 cm-’ using normal Te and Se and a resolution of 0.5 cm-‘. The bandheads for the ‘3@Te80Se, ‘**TesOSe,‘26Te80Se,‘3qe78Se, ‘2*Te78Se,126Te78Se, “@Tes2Se and ‘28Te82Seisotopic species were well resolved for the 1-O and O-l sequences but not for the O-O sequence. For the latter the high-resolution measurements were used. A Deslandres table for the lzaTe8’Se bandheads is given in Table IV. The best values for AG;,z and AG’i,* are obtained from the l-0, O-l, and O-O bands. The value for w,x: obtained earlier from an extended fluorescence series ( 7) was consistent with the present data (after isotopic scaling) and was therefore adopted, viz. w,xi = 0.72 cm-‘. The corresponding value for the excited state was obtained from the separation of the 2-l and O-l bands and the value for AG;,zr viz. W,X: = 0.86 cm-‘. The vibrational constants for both states are summarized in Table II.
’ NRCC No. 30270
0022-2852189 $3.00 Copyright
0
1989 by Academic
All rights of reproduction
218 Press. Inc.
in any form reserved.
8783.606 8783.812 8783.706 8783.797 8783.897 8783.984 8784.078 8784.160 8784.238 8784.319 8784.392 8784.484 8784.634 8784.802 8784.886 8784.728 8784.788 8784.840 8784.896 8784.944 8784.990 8786.038 8786.078 8786.118 8786.163
6 6 7 8 9 10 11 12 13 14 16 18 17 18 19 26 21 22 23 24 26 28 27 28 29 30 31 32 33 34
71 6j 6) 8)
4
2) 3) 2) 4) 3) 2) 4) 3)
:;
8) +j
3j
6)* 6), 10). 5) 0). 6)
8782.326 8782.181 8782.044 8781.908 8783.766 8781.819 8781.470 8781.319 8781.162 8781.002 6780.843 8786.678 8780.612 8780.341 8780.177 8780.883 8779.636 8779.648 8‘179.486 8779.288 8779.091 8778.896 8778.706 8776.667 8778.309 8776.163 8777.897 8777.691 8777.476 8777.281 8777.044
P(J) 4) -8) -7) -3) -2) -4) -6) -4) -I)* .11)* -9)+ .12)* .12)* .16). -7) -6) -3j -4) -4j -4) -3) -7) -2) -4) -1) -4) -4) -1) -4j -4) -3) :3 61 62 63 64 66
36 36 37 38 39 40 41 42 43 44 46 46 47 48 49 60 61 62 63 64 66 66 67 68
J
8786.163 8786.116 8786.078 8786.038 8784.990 8784.944 8784.896 8784.840 8784.786 8784.728 8784.866 8784.602 8784.634 8784.464
8786.329
R(J)
(
( ( ( ( ( ( ( ( ( ( C i (
3) 0) 0) 1) -4) -3) -3) -6) -4) -3) -6) -6j -6) -6)
Ii
81
l
89 96 91 92 93
88
86 87
8784.392 8784.319 8784.238 8784.160 6784.076 8783.984 8783.897 8783.797 8783.706 8783.612 8783.606 8783.401 8783.292 8783.184 8783.069 8782.966 8782.836 8782.709 8782.686 8782.441 8782.326 8782.181 8782.044 8781.908 8781.766 8781.619 8781.470 8781.319 8781.162 8781.002
R(J)
( -4) 8768.661 ( -2) 8768.237 ( -4) 8787.923 ( 0) 8767.606 ( 0) 8767.284 ( -4) 8766.967 ( -1) 8766.826 ( -7)r 8766.299 ( -2) 8766.962 ( 3)* 8766.626 ( 0) 8766.288 ( 1) 8764.943 ( 0) 8764.696 ( 3) 8764.260 C 2) 8763.902 ( 6j. 8783.647 ( Cl)* 8763.188 ( 2) 8762.826 ( 4) 8782.466 (-ll)* 8762.099 ( 4)* ( -6) 6761.362 ( -4) 8760.984 ( 1) 8760.693 ( 3) 8760.221 ( 3) 8769.832 ( 3) 8769.449 ( 6) 8769.066 ( 4) 8768.671 ( 1)s 8768.278
P(J)
( -6)* ( 1)~ (-13)* ( -4) (-10)~ ( -7) ( -2) ( -4) ( -4)
0) 4) ( 1) ( 0) ( 1) ( 1) ( -1) ( 2) C 4)* i 3j ( 1) ( -1) ( 2) ( 1)
( (
( 1) ( 0) ( 3j ( 4) ( 6) ( 3)
differences in units of 0.001 cm-‘. H denotes bandhead.
x; 0) 3)
:; 3) 6) 1)
i', 2)
67 68 69 70 71 72 73 74 76 76 77 78 79 80 81 82 83 84 86
66
-3) -1) -1) 0) 0) -1) 1) 1) 1) -2) 1) 1) 1) 1) 1) 1)
-2) -2)
8776.826
8776.601 9776.374 8776.146 8776.914 8776.680 8776.442 8776.200 8774.968 8774.711 8774.462 8774.207 8773.964 8773.696 8773.434 8773.171 8772.903 6772.834 6772.363 6772.084 6771.607 8771.626 8771.242 6770.966 6776.867 6770.371 6770.078 8789.777 8789.473 8769.171 8788.886
J
P(J)
* Blended line not used in the least-squares fit. Numbers in parentheses denote the (obs-talc)
R(J)
J
Vacuum Wavenumbers and Rotational Assignments for Lines in the O-O band of the h 0+-X, O+ Subsystem of ““Te80Se (in cm-‘)
TABLE 1
220
NOTES TABLE II Molecular Constants for ‘30Te80Se
80 10' D, ro
AG% w
e
wx ee Constants
x, o+
b 0+
Constant
o.059668(251a
0.061116(25)
1.05(21)
1.00(21)
2.3896(5)
2.3611(5)
288.1,
311.6,
289.8,
313.0,
0.8,b
0.72’
obtained
from the
analysis
of the O-O band
8782.827(2)
vo
0.120784(35) -0.0014484(10) lO'(D'+D")
2.05(29)
lOuiD'-D")
0.044(12)
Note. Units are cm-’ except for r. which is given in A. ’ Error limits are 30. b From 2- 1 and 0- 1 bandheads and AG,,* ’ From Ref. ( 7).
TABLE III Comparison of Bond Lengths (in A) in Related Molecules” Molecule
r,(exp.)
r,(calc.Ib
exp. -talc.
SeS
2.0338
2.0299
co.0039
TeS
2.2318
2.2256
+0.0062
TeSe
2.3611
2.3635
-0.0024
a Data from (2, 4, 6). * Mean of the values for the homonuclear diatomic molecules.
221
NOTES TABLE IV Deslandres Table for Bands of “@Te“Se (in cm -I ) V”
0
8785.33
(311.64)
(288.14) 1
9073.47
2
1
0
V’
3
8473.69
(288.03)
(311.75)
8761.72
(310.15)
(286.40)
(286.53) 9048.25
2
8451.57
(310.28)
8737.97
(308.67)
8429.30
(284.99)
3
I
9022.96
Note. Measurements for the Au = 0 bands refer to bandheads taken from the high-resolution spectrum with separated isotopes. Other measurements are taken from the low-resolution run with normal Te and Se: a correction of 0.14 cm-’ has been added to allow for the difference in resolution. ACKNOWLEDGMENTS E.H.F. and K.D.S. thank the National Research Council of Canada and the Deutsche Forschungsgemeinschaft (Project SFB42/B2) for financial support during their visit to Ottawa. G.Z.X. thanks the Natural Sciences and Engineering Research Council of Canada and the National Science foundation of China for the award of a Visiting Fellowship. We all thank M. Barnett for valuable technical assistance. REFERENCES R. WINTER, E. H. FINK, J. WILDT, AND F. ZABEL,Chem. Phys. Lett. 94, 335-338 ( 1983). E. H. FINK, H. KRUSE, AND D. A. RAMSAY, J. MO/.Spectrosc. 119, 337-387 (1986). G. HERZBERG,“Spectra of Diatomic Molecules,” Van Nostrand, New York, 1950. K. P. HUBERAND G. HERZBERG,“Constants of Diatomic Molecules,” Van Nostrand-Reinhold, New York, 1979. 5. E. H. FINK, H. KRUSE, D. A. RAMSAY, AND M. VERVLOET,Canad. J. Phys. 64,242-245 ( 1986). 6. E. H. FINK, H. KRUSE, D. A. RAMSAY, AND D.-C. WANG, Mol. Phys. 60,277-290 ( 1987). 7. F. AHMED,R. F. BARROW,AND K. K. YEE, J. Phys. B 8,649~651( 1975). E. H. FINK’ K. D. SETZER~
1. 2. 3. 4.
Physikalische Chemie Fachbereich 9 Bergische Universitat-Gesamthochschule Wuppertal D-5600 Wuppertal 1. Federal Republic of Germany D. A. RAMSAY M. VERVLOET G. 2. Xu3 Herzberg Institute of Astrophysics National Research Council of Canada Ottawa, Ontario, Canada KlA OR6 Received February 2 I, 1989 ’ NRCC Visiting Scientists, 1988. 3 NRCC Visiting Scientist, 1988, from the Institute of Chemistry, Academia Sinica, Beijing, China
OF MOLECULAR
SPECTROSCOPY
136,2 18-221 ( 1989)
Rotational Analysis of the O-O Band of the b O+ + X1 O+ System of 130Te80Se’
The b 0+-X, O+, X, 1 band system of TeSe has been observed in emission in the near infrared using a, discharge flow system (1). In the present work the O-O band of the b 0+:X, O+ subsystem is recorded at high resolution using separated “@fe and 8oSe isotopes, and a rotational analysis is carried out. The experimental apparatus has been described in an earlier publication (2) and the conditions were similar to those given in Ref. (I). Isotopically enriched “@I’e(99.29%) and “Se (99.57%) were used and were obtained from Oak Ridge National Laboratories. The infrared chemiluminescence was focused on the entrance iris of a Bomem DA3.002 Fourier transform spectrometer and a spectrum was recorded in the region 7530 to 8800 cm-’ using a liquid nitrogen cooled germanium detector and a resolution of 0.02 cm-‘. The O-O band of the b 0+-X, O+ subsystem of ‘qesoSe consists of a simple P and R branch. Lines are observed up to J - 100; the lines in the R branch form a head at J - 40 and the lines with higher J values overlap those with lower J values and also the low-J lines of the P branch. As a result no clear zero gap is observed. The rotational numbering was determined by assuming that the ground state bond length lies close to the mean of the values for Tez and Sez (see below). The assignments are given in Table I. The frequencies of the lines were fitted by least squares to the usual quartic expression (3) and the molecular constants obtained are given in the lower part of Table II. The overall standard deviation of the fit was 0.003e, cm-’ but the stronger lines of the P branch which are free from overlapping are fitted to rlIO.001 cm-‘. The values of Bb, BE, Db, and 06 derived from the above numbers are given in the upper part of Table II together with the values for the bond lengths rb and r6. The values for D lie close to those calculated from the approximate Kratzer relation (3), Do - 4Bi/wZ where AGl,z is substituted for w, viz. 10’0’ = 1.02 cm-‘, lOgO” = 0.94 cm-‘. A few ground state bond lengths for related molecules are given in Table III. The values for the heteronuclear molecules lie close to the means of the values for the corresponding homonuclear molecules and provide the justification for adopting the present rotational numbering for TeSe. The intensity data are not sufficiently accurate to determine a rotational temperature but the overall distribution is consistent with a temperature of -3 10 K as has been found in related systems (2, 5, 6). The R-head of the b 0+-X, 1 subband is observed at 755 1.84 cm-’ but the intensity of the subband was insufficient to justify a rotational analysis. Nevertheless, we obtain a value for the Xz I-X, O+ separation, viz. 1233.49 cm-‘. This value differs from that given in the literature (7) by one vibrational quantum, indicating an error in the vibrational numbering in the earlier work. A stronger spectrum was obtained by us in the region 7300 to 9100 cm-’ using normal Te and Se and a resolution of 0.5 cm-‘. The bandheads for the ‘3@Te80Se, ‘**TesOSe,‘26Te80Se,‘3qe78Se, ‘2*Te78Se,126Te78Se, “@Tes2Se and ‘28Te82Seisotopic species were well resolved for the 1-O and O-l sequences but not for the O-O sequence. For the latter the high-resolution measurements were used. A Deslandres table for the lzaTe8’Se bandheads is given in Table IV. The best values for AG;,z and AG’i,* are obtained from the l-0, O-l, and O-O bands. The value for w,x: obtained earlier from an extended fluorescence series ( 7) was consistent with the present data (after isotopic scaling) and was therefore adopted, viz. w,xi = 0.72 cm-‘. The corresponding value for the excited state was obtained from the separation of the 2-l and O-l bands and the value for AG;,zr viz. W,X: = 0.86 cm-‘. The vibrational constants for both states are summarized in Table II.
’ NRCC No. 30270
0022-2852189 $3.00 Copyright
0
1989 by Academic
All rights of reproduction
218 Press. Inc.
in any form reserved.
8783.606 8783.812 8783.706 8783.797 8783.897 8783.984 8784.078 8784.160 8784.238 8784.319 8784.392 8784.484 8784.634 8784.802 8784.886 8784.728 8784.788 8784.840 8784.896 8784.944 8784.990 8786.038 8786.078 8786.118 8786.163
6 6 7 8 9 10 11 12 13 14 16 18 17 18 19 26 21 22 23 24 26 28 27 28 29 30 31 32 33 34
71 6j 6) 8)
4
2) 3) 2) 4) 3) 2) 4) 3)
:;
8) +j
3j
6)* 6), 10). 5) 0). 6)
8782.326 8782.181 8782.044 8781.908 8783.766 8781.819 8781.470 8781.319 8781.162 8781.002 6780.843 8786.678 8780.612 8780.341 8780.177 8780.883 8779.636 8779.648 8‘179.486 8779.288 8779.091 8778.896 8778.706 8776.667 8778.309 8776.163 8777.897 8777.691 8777.476 8777.281 8777.044
P(J) 4) -8) -7) -3) -2) -4) -6) -4) -I)* .11)* -9)+ .12)* .12)* .16). -7) -6) -3j -4) -4j -4) -3) -7) -2) -4) -1) -4) -4) -1) -4j -4) -3) :3 61 62 63 64 66
36 36 37 38 39 40 41 42 43 44 46 46 47 48 49 60 61 62 63 64 66 66 67 68
J
8786.163 8786.116 8786.078 8786.038 8784.990 8784.944 8784.896 8784.840 8784.786 8784.728 8784.866 8784.602 8784.634 8784.464
8786.329
R(J)
(
( ( ( ( ( ( ( ( ( ( C i (
3) 0) 0) 1) -4) -3) -3) -6) -4) -3) -6) -6j -6) -6)
Ii
81
l
89 96 91 92 93
88
86 87
8784.392 8784.319 8784.238 8784.160 6784.076 8783.984 8783.897 8783.797 8783.706 8783.612 8783.606 8783.401 8783.292 8783.184 8783.069 8782.966 8782.836 8782.709 8782.686 8782.441 8782.326 8782.181 8782.044 8781.908 8781.766 8781.619 8781.470 8781.319 8781.162 8781.002
R(J)
( -4) 8768.661 ( -2) 8768.237 ( -4) 8787.923 ( 0) 8767.606 ( 0) 8767.284 ( -4) 8766.967 ( -1) 8766.826 ( -7)r 8766.299 ( -2) 8766.962 ( 3)* 8766.626 ( 0) 8766.288 ( 1) 8764.943 ( 0) 8764.696 ( 3) 8764.260 C 2) 8763.902 ( 6j. 8783.647 ( Cl)* 8763.188 ( 2) 8762.826 ( 4) 8782.466 (-ll)* 8762.099 ( 4)* ( -6) 6761.362 ( -4) 8760.984 ( 1) 8760.693 ( 3) 8760.221 ( 3) 8769.832 ( 3) 8769.449 ( 6) 8769.066 ( 4) 8768.671 ( 1)s 8768.278
P(J)
( -6)* ( 1)~ (-13)* ( -4) (-10)~ ( -7) ( -2) ( -4) ( -4)
0) 4) ( 1) ( 0) ( 1) ( 1) ( -1) ( 2) C 4)* i 3j ( 1) ( -1) ( 2) ( 1)
( (
( 1) ( 0) ( 3j ( 4) ( 6) ( 3)
differences in units of 0.001 cm-‘. H denotes bandhead.
x; 0) 3)
:; 3) 6) 1)
i', 2)
67 68 69 70 71 72 73 74 76 76 77 78 79 80 81 82 83 84 86
66
-3) -1) -1) 0) 0) -1) 1) 1) 1) -2) 1) 1) 1) 1) 1) 1)
-2) -2)
8776.826
8776.601 9776.374 8776.146 8776.914 8776.680 8776.442 8776.200 8774.968 8774.711 8774.462 8774.207 8773.964 8773.696 8773.434 8773.171 8772.903 6772.834 6772.363 6772.084 6771.607 8771.626 8771.242 6770.966 6776.867 6770.371 6770.078 8789.777 8789.473 8769.171 8788.886
J
P(J)
* Blended line not used in the least-squares fit. Numbers in parentheses denote the (obs-talc)
R(J)
J
Vacuum Wavenumbers and Rotational Assignments for Lines in the O-O band of the h 0+-X, O+ Subsystem of ““Te80Se (in cm-‘)
TABLE 1
220
NOTES TABLE II Molecular Constants for ‘30Te80Se
80 10' D, ro
AG% w
e
wx ee Constants
x, o+
b 0+
Constant
o.059668(251a
0.061116(25)
1.05(21)
1.00(21)
2.3896(5)
2.3611(5)
288.1,
311.6,
289.8,
313.0,
0.8,b
0.72’
obtained
from the
analysis
of the O-O band
8782.827(2)
vo
0.120784(35) -0.0014484(10) lO'(D'+D")
2.05(29)
lOuiD'-D")
0.044(12)
Note. Units are cm-’ except for r. which is given in A. ’ Error limits are 30. b From 2- 1 and 0- 1 bandheads and AG,,* ’ From Ref. ( 7).
TABLE III Comparison of Bond Lengths (in A) in Related Molecules” Molecule
r,(exp.)
r,(calc.Ib
exp. -talc.
SeS
2.0338
2.0299
co.0039
TeS
2.2318
2.2256
+0.0062
TeSe
2.3611
2.3635
-0.0024
a Data from (2, 4, 6). * Mean of the values for the homonuclear diatomic molecules.
221
NOTES TABLE IV Deslandres Table for Bands of “@Te“Se (in cm -I ) V”
0
8785.33
(311.64)
(288.14) 1
9073.47
2
1
0
V’
3
8473.69
(288.03)
(311.75)
8761.72
(310.15)
(286.40)
(286.53) 9048.25
2
8451.57
(310.28)
8737.97
(308.67)
8429.30
(284.99)
3
I
9022.96
Note. Measurements for the Au = 0 bands refer to bandheads taken from the high-resolution spectrum with separated isotopes. Other measurements are taken from the low-resolution run with normal Te and Se: a correction of 0.14 cm-’ has been added to allow for the difference in resolution. ACKNOWLEDGMENTS E.H.F. and K.D.S. thank the National Research Council of Canada and the Deutsche Forschungsgemeinschaft (Project SFB42/B2) for financial support during their visit to Ottawa. G.Z.X. thanks the Natural Sciences and Engineering Research Council of Canada and the National Science foundation of China for the award of a Visiting Fellowship. We all thank M. Barnett for valuable technical assistance. REFERENCES R. WINTER, E. H. FINK, J. WILDT, AND F. ZABEL,Chem. Phys. Lett. 94, 335-338 ( 1983). E. H. FINK, H. KRUSE, AND D. A. RAMSAY, J. MO/.Spectrosc. 119, 337-387 (1986). G. HERZBERG,“Spectra of Diatomic Molecules,” Van Nostrand, New York, 1950. K. P. HUBERAND G. HERZBERG,“Constants of Diatomic Molecules,” Van Nostrand-Reinhold, New York, 1979. 5. E. H. FINK, H. KRUSE, D. A. RAMSAY, AND M. VERVLOET,Canad. J. Phys. 64,242-245 ( 1986). 6. E. H. FINK, H. KRUSE, D. A. RAMSAY, AND D.-C. WANG, Mol. Phys. 60,277-290 ( 1987). 7. F. AHMED,R. F. BARROW,AND K. K. YEE, J. Phys. B 8,649~651( 1975). E. H. FINK’ K. D. SETZER~
1. 2. 3. 4.
Physikalische Chemie Fachbereich 9 Bergische Universitat-Gesamthochschule Wuppertal D-5600 Wuppertal 1. Federal Republic of Germany D. A. RAMSAY M. VERVLOET G. 2. Xu3 Herzberg Institute of Astrophysics National Research Council of Canada Ottawa, Ontario, Canada KlA OR6 Received February 2 I, 1989 ’ NRCC Visiting Scientists, 1988. 3 NRCC Visiting Scientist, 1988, from the Institute of Chemistry, Academia Sinica, Beijing, China