J. Phys. Chem. 1984,88, 401-404 H(I) 656.3nm
H (1) 656.3nm H(I) 656.3 nm
I
+"-,Ad
iI
L L b 4
I L
I I'
% !
il&w
A. 6. C Figure 7. Quantitative analysis for hydrogen: expanded region of H I emission with varied amounts of CH, sample introduced. These data were from the same scans and samples shown in Figure 6 . The amount of CH4 added decreases stepwise from case A to case C. Abbreviated
spectra plotted on an expanded scale. atomic emission data it appeared completely unnecessary to proceed to the extreme resolution capabilities (0.03 cm-') of the interferometer because no further C I spectral features of interest need to be resolved and the acquisition time would increase unreasonably. In fact, plots of the C I emission (see figure 6) reveal that even the low-resolution case ( 2 cm-') is adequate to isolate the principal C I emission at 10995 cm-' (909.5 nm). The benefit of using low resolution is shortened data acquisition time (e.g., 1 s for one interferogram). This will be important in future testing with the type of transient sample introduction encountered in chromatographic analysis. In a combined interferometric-chromatographic application, the maximum allowed interferometer sampling time would be about 1 s to maintain reasonable chromatographic resolution.
401
Quantitative Analysis. Figure 6 shows that the C I emission intensity is related to the amount of CH, sample introduced. Figure 7 shows that H I emission intensity is also related to the amount of CHI introduced. These relationships form the preliminary basis for quantitative carbon and hydrogen determination by FT-NIR atomic emission. Formula Stoichiometry. It would be desirable if these C I and H I emission lines could not only reflect the percent C and H content of the sample but also serve to directly evaluate the C/H chemical formula stoichiometry ratio of the compound originally introduced. In order to study this further, we measured the C I and H I emissions simultaneously from several samples containing varied amounts of CH4 atomized in the plasma. If CH4 bond dissociation in the ICP is complete for each different amount of CH4 introduced here, the free atomic C / H intensity ratio observed in the hot plasma should ideally depend only on the CHI compound formula stoichiometry and on the lines in question. The C / H intensity ratio should ideally not depend on the total amount of CH4 introduced. Within experimental error and the amounts of CH, studied here, this condition was achieved and is illustrated in Figures 6 and 7. Once calibration and normalization for inherent line sensitivities has been performed, relative C / H intensity ratios measured by FT-NIR atomic emission in the ICP therefore appear to be useful in evaluation of the compound formula stoichiometry. The authors deem it fortuitous that this intensity ratio does not depend on the reproducibility, accuracy, or amount of sample introduction. In fact, three different injected amounts of the same compound appear to give an invariant C / H ratio. It therefore appears possible to accurately determine C/H ratios even for uncalibrated amounts of injected sample. This is a result of the simultaneous monitoring of C I and H I emissions inherent in a Fouriertransform interferometric approach. Acknowledgment. This work was supported in part by N S F Grant CHE-8109570. Registry No. Carbon, 7440-44-0;hydrogen, 1333-74-0;sulfur, 770434-9.
Infrared Bands of Isotopic Carbon Disulfide Romola D'Cunha? Carl J. Seliskar,f J. R. Manheim,l and K. Narahari Rao* Department of Physics, The OhioState University, Columbus, Ohio 43210 (Received: May 25, 1983)
-
A study of the infrared spectra of isotopically enriched carbon disulfide in the region 3-5 wm obtained at 0.01-cm-' resolution led to the identification and interpretation of two new band systems of 12C32S34S, 02O1 OOoO and 03'1 01 '0. For the ( v I + v 3 ) bands of 12C32S34S, 12C32S33S, 12C32S2, and 13C32S2 which also appeared in the spectra recorded, improved molecular constants were obtained for the levels involved. +
Introduction The infrared spectra of carbon disulfide and its isotopic varieties have been the subject of several studies in the At the present time, it seemed useful to further investigate the spectra of the mixed isotopic species 12C32S34S.An enriched sample of 12C32S34S was provided by the isotopic separation group at the Mound facility of the Monsanto Research Corp. It has the approximate composition 80% 12C32S34S, 4% 12C32S2, and 9% 12c34S2 On leave from Spectroscopy Division, Bhabha Atomic Research Centre, Bombay 400 085, India. *Department of Chemistry, University of Cincinnati, Cincinnati, OH
45221.
Wright Patterson Air Force Base, OH 45433.
0022-3654/84/2088-0401$01.50/0
with the remaining being the mixed species of 13Cand 33S.Incidentally, 12C32S34S is the first highly enriched entity in the liquid thermal diffusion separation of 34Susing carbon disulfide and its (1) D. F. Smith, Jr., and J. Overend, Spectrochim. Acta, Part A, 26, 2269
(1970).
(2) A. G. Maki, J . Mol. Spectrosc., 47, 217 (1973). (3) A. G. Maki and R. L. Sam, J . Mol. Spectrosc., 52, 233 (1974). (4) G. Blanquet, J. Walrand, and C. P.Courtoy, J. Mol. Spectrosc., 72, 227 (1978). (5) J. Walrand, G . Blanquet, and C. P. Courtoy, J . Mol. Spectrosc., 74, 165 (1979). (6) K. Jolma and J. Kauppinen, J . Mol. Spectrosc., 82, 214 (1980). (7) A. H. Guenther, J . Chem. Phys., 31, 1095 (1959). (8) J. Kauppinen and K. Jolma, J . Mol. Spectrosc., 85, 314 (1981).
0 1984 American Chemical Society
402
The Journal of Physical Chemistry, Vol. 88, No. 3, I984
TABLE I: Observed Wavenumbers (under Vacuum, cm-l) of the 02'1 J
3
2 3 19.6636
10
2319.8738 2 320.0 796 2320.2859 2320.4922 2320.6980 2320.9043 2321.1101
4 5 6 7 8 9 11 12 13
19 20
2321.3125 2321.5144 2321.7205 2321.9226 2322.121 1 2322.3230 2322.5215 2322.7239 2322.9219 2323.1165
21 22 23 24 25 26 27 28 29 30
2323.3184 2323.5132 2323.7112 2323.9058 2324.1001 2324.2947 2324.4888 2324.6792 2324.8738 2325.0642
31
2325.2549 2325.4451 2325.6355 2325.8223 2326.0127 2326.1995 2326.3860 2326.5725 2326.7593 2326.941 9
14 15 16 17 18
32 33
34 35 36 37
38 39 40
0-c
R(J)
-
0.0007 0,0021 0.0002 0.0010 0.0013 0.0012 0.0004 0.0010
0-c
P (J)
231 7.7549 2317.5408 2317.3230 2317.1133 2316.8916 2316.6741
0.0008 0.0020 0.0014 0.0016 0.0016 0.0001 0.0017 0.001 1 0.0006 0.0031
2316.4563 2316.2383 2316.01 66 231 5 7991 231 5.5774 2315.3560 2315.1343 2314 .go87 2314.6873
0.0016 0.0006 0.0015 0.0004 0.0001 0.0004 0.0012 0.0012 0.0010 0.0002
231 4.2361 231 4.01 05 2313.7852 231 3.5596 2313.3340 231 3.1045 231 2.8755 231 2.6460 2312.4163 2312.1873
- 0.0000
231 1.9539 231 1 . 7 2 4 4 231 1 .4910 231 1.2581 231 1.0237 2310.791 3 2310.5503 2310.3169 2310.0835 2309.8428
-
-
0.0000 0.0008 - 0.0013 0.0009 0.0001 - 0.0003 - 0.0000 0.001 1 - 0.0012
231 4.461 7
-
-
+-
00'0 Band of 12C32S34S J
41 42 0.0019 0.0007 0.0027 0.0037 0.0007 0.0008
43 44 45
0.0003 0.0009 0.0012 0.0016 0.0008 0.0007 0.0012 0.0013 0.0006 0.0009
50
0.0014 0.0016 - 0.0011 0.0003 0.0021 0.0006 - 0.0000 - 0.0002 0.0002 0.0015
- 0.0006
-
D'Cunha et al.
0.0020 0.0010 0.0010 0.0014 0.0026 0.0035 0.0010 0.0019 0.0021
46
47 48 49 51 52 53 54 55 56
57 58 59 60 61 62 63 64
65 66 67 68 69 70 72 ?3 71;
75 76 77 78 79 80
Spectra The infrared spectra of this mixed isotope were recorded in the region 2000-2900 cm-' with the Fourier transform spectrometer at the Kitt Peak National Observatory in Tucson, A Z with a resolution of about 0.01 cm-I. Spectra were recorded at room temperature with a path length of 50 cm at pressures ranging from 1 to 10 torr. A fast Fourier transform algorithm was used to retrieve the spectral information from the interferogram. The spectral lines were calibrated relative to CO lineslo which were simultaneously recorded. Some of the spectra also showed overlap with atmospheric COz lines. Molecular constants were obtained by fitting the data with the least-squares program of Zare et al.," suitably modified to treat vibration-rotation bands of linear molecules. Blended lines were omitted in these evaluations. Results and Discussion In the 2300-2350-~m-~region, two new bands of 12C3zS34S were identified. They are the 2-2 transition 02O1 00'0 and the associated 11-II band 03l1 01'0. the Z-Z band was rather intense and appeared well separated from other overlapping structure. As may be seen from Figure 1, the I-type doubling was clearly seen in lines for J > 13 in the II-II band. It has also been
-
-
(9) W.M.Rutherford, Ind. Eng. Chem. Proc. Des. Deu., 17, 77 (1978). (10)G. Guelachvili, J. Mol. Spectrosc., 75, 251 (1979). (1 1) R.N.Zare, A. L. Schmeltekopf, W. J. Harrop, and D. L. Albritton, J. Mol. Spectrosc., 46,37 (1973).
0-c
2327.1287 2327.3113 2327.4944 2327.6768 2327.8599 2328.0386 2328.221 2 2328.3999 2328.5789
0.0013 0.0002 0.0001 0.0004 0.0016 - 0.0007 0.0018 0.0008 0.0007
2309.6055 2309.3682 2309.131 1 2308.8904 2308.653 1 2 308.4080 2308.1709 2307.9258 2307.685 1 2307: 4397
2328.9329
- 0.0016
2329.1 I16 2329.2864 2329.461 7 2 329.6 365 2329.81 52 2329.9866 2330.1614 2330.3323
0.0002 - 0.0014 - 0.0021 - 0.0022 0.0021 - 0.0006 0.0013 - 0.0003
2307.1951 2306.9502 2306.7090 2 306.4600 2306.21 51 2305.9663 2305.7212 2305.4727 2305.2239 2304.9751
2330.6746 2330.8455
-
2331.6892
2331 .E567
2332.01 98 2332.1873
0.0011 0.0007
0.0001 0.0007 - 0.0020 - 0.0000
71
81
thermal diffusion factor is apparently a n o m a l o ~ s . ~
R(J)
2332.51 76 2332.6807 2 3 32.8 40 1 2333.0037 2333.1670 2333.3262 2333.4856
0.0016 0.0015 - 0.0018 - 0.0006 0.0013 - 0.0000
2333.8047 2333.9639
0.0002 0.0010
-
0.0007
0-c
P(J)
- 0.0019 - 0.0007 0.001 1
- 0.0004 0.0024 0.0017 0.0023 - 0.0005 0.001 1 - 0.0008
-
-
0.0017
- 0.0021 0.0018
- 0.0012 0.0003
- 0.0015 0.001 I 0.0005 0.0006 0.0013
2304.7222 2304.4734 2304.2244 2303.9678 2303.7151 2303.4624 2303.2100 2302.9568 2302.7002 2302.4475
- 0.0012
2302.1873 2301.9307 2301.6741 2301 . & I 7 5 2301.1580 2300.8965 2 300.6360 2300.3794 2300.1 I50 2299.8545 2299.5940
-
-
0.0005 0.0031 0.0016 0.0017 0.0011 0.0000 0.0015 0.0001 0.0029
0.0013
- 0.0010
-
0.0001 0.0014 0.0006 0.0016 0.0022 0.0018 0.0015
0.oooj 0.0015
noticed that the intensity of the IIc-IIe component dies down more rapidly than the IIf-IIf component. In analyzing the various bands, a few low J lines were first picked out by inspection and on the basis of the molecular parameters already available in the literature for carbon disulfide, probable J values were assigned to them. The wavenumbers for these lines were then fitted to the appropriate term value expressions to obtain an approximate starting set of rotational constants. These constants were subsequently used to predict transitions with higher J values. By iterating this procedure, it was possible to arrive at J assignments and molecular parameters that reproduced all observational data for each band. For 12C32S34S this is the first experimental determination of the 1-type doubling constant q. Although standard procedures have been used in these evaluations, a brief clarification of what exactly has been done may help keep matters in the proper perspective. The two components of the band of this mixed isotopic variety were fitted to the term value expression
E / h c = [G(o)- B,P]
+ (B, A
3/2q,)J(J
*
+ 1) - D,P(J + 1)'
where the sign refers to the upper and lower components of the I-doublet, respectively. The computer program used calculates ) the upper and the effective B, values given by (B, ' / * q Ufor lower levels involved in the transition. The qti values are obtained as the difference between the effective B, values so determined. For 12C32S34S, the q values came out to be 7.778 X 10-5cm-' for 01'0 level and 13.71 X cm-l for the 03I1 level. These are comparable to the corresponding v a l ~ e sfor ~ , 12C32S2, ~ viz. 7.695 X 10-5 and 7.81 X cm-I for its 01'0 and 14.44 X 10-5 cm-' for its 03'1 level.
*
The Journal of Physical Chemistry, Vol. 88. No. 3, 1984 403
IR Spectra of Isotopic CS2 TABLE 11: Observed Wavenumbers (under Vacuum, c m - l ) of t h e 03'1
~
+
01'0 Bands of '2C3zS"4s
- -
f-f
e-e J
0-c
R(J)
I
-
-
0-c
P(J)
2321.65459:
R (J)
0-c
0-c
P(J)
J
1
2321.6545"
2
2 2320.6047"
3 4
2 322.2 922 ?: 2322.4983" 2322.7004:': 2322.9221:': 2322.7346"
5 6 7 8 9 IO 11
2323.7346" 2323.9292:': 2324.1233 2324.321 8 2324.5276 2324.7222
12
13 14 I5 16
17 I8 19
2325.1184
20 21 22 23 24 25 26 27
2325.51 15 2325.7056 2325.8999 2326.0906 2326.2852 2326.4795 2326.6702
28 29 30
2327.0430 2327.2339 2327.4241
31 32
2327.7935 2327.9761 2328.1631 2328.3494 2328.5325
33 34 35 36
37 38
39 40
41 42
43 44 45 46 47 48 49 50
51 52
2328.8899 2329,0725 2329.2554 2329.4341 2329.6094 2329.7842 2329.9629 2330.1382 2330.3091 2330.8262
-
0.0023 0.0043 0.0023 0.0021
-
0.0006
-
0.0004 0.0001 0.0005 0.0019 0.0001 0.0030 0.0030
-
-
0.0030 0.0006 0.0024
-
0.0007 0.0032 0.0007 0.0024 0.0026
-
-
0.0025 0.0001 0.0034 0.0035 0.0008 0.0011 0.0014 0.0011 0,0022
0.0038
2322.2922+< 2322,4983" 2322.7004s: 2 322.922 1 :;' 2322.7346"
2 3 1 9.95 56;': 2319.7378" 2319.5161" 2319.2983:': 2319.0847" 231 8.8630" 2 3 1 8.645 3 9: 23 18.42369:
2323.7346s: 2323.9292:': 2324.1426 2324.341 1 2324.5474 2324.7454
231 6.8450
2316.6 I55 2316.3899 2316.1609 231 5.931 4 231 5.6980 23 1 5.4646 23 15.231 2 2314.9983 231 4.7688 2314.5315 231 4.2981 2313.8201 231 3.5828
-
-
-
-
0.0004 0.0017 0.0014 0.0016 0.0024 0.0000 0.0014 0.0022
2325.5425 2325.7405 2325.9390 2326. I333 2326.3318 2326.5259 2326.7168
0.0020
2327. IO55
0.0027 0.0006 0.0029
-
57 58
59 60
61 62 63 64 65 66
69 70
6
7 8 9 IO 11
12
13 14 15 16
17
-
0.0007 0.0002 0.0014 0.0006 0.0020 0.0013 0.0023
-
0.0002
2316 .8682 2316.6426 2316.4136 2316.1880 2315.9622 2315.7329 231 5.5037 231 5.2742 231 5.0447 2314.5823 2314.3489
-
-
-
0.0013 0.0012 0.0019 0.0006 0.0012 0.0001 0.0006 0.0004 0.0002
-
0.0003 0.0017
-
0.0017 0.0014
18 19 20 21 22 23 24 25 26 27
28 29 30
31 32
0.0014 0.0006
2328.0618 2328.2483
-
0.0015 0.0009
231 3 .8860 23 13.6492
33 34 36
231 2.6226 23 12.38 I6 2312.1404 231 1.8953 231 1.6504 231 1.4058 231 1.1609 23 10.91 58 231 0.6670 231 0.41 80 2310.1692 2309.9202 2309.6714 2 309.4 187 2309. I621
37
-
0.0011 0.0001 0.0016 0 * 0000 - 0.0006 - 0.0004 0.0006 0.0020 0.0007
2308.1475 2307.8948 2307.6382 2307.3777 2307.1172 2306.8606 2306.6038
2328.9988 2329.1814 2329.3682 2329.5508 2329.7378 2 329.9202 2330.0994 2330.2859
-
2303.6919 2303.4236 2303.1553
-
0.0012
0.0034
-
2331.7129 2331 .e877 2332.0625
0.0009 0 * 0002 0.0004
2332.5835 2332.7549 2332.9258
o.ooog
0.0020 0.0012
0.0013 0.0017 0.0040 0.0018 0.0015
2333.7732 2333.9446
72
-
0.0009 0.0026
2333.4351
2305.0254 2304.7649 2304.4966
-
0.0005 0.0025 0.0006 0.0023 0.0009 0.0006 0.0027 0.0023
231 2.7080 2312.4707 231 2.2300 23 1 1 .9966 231 1.7515 231 1.5144 231 1.2771
0.0000 0.0002
-
0.0018 0.0029 0.0006
2334.4380
71 73 74 75
2319.9556;': 231 9.73785 23 19.51 6 .'1 2 3 1 9 .2983:': 23 19.0847" 2 3 18 .8630" 2318.64535 2 3 1 8.42 36$;
35
67 68
3 4 5
0.0001
2325.1460
53 54 55 56
-
0.0018 0.0020 0.0024 0.0003
2320.6047?:
-
0.0016 0.0008 0.0010
76
-
0.0001 0.0007 0.0016 0.0004 0.0033 0.0014
2 3 10.0603 2309.8 191 2309.5745 2309.3257 2309.0806 2308.83 I8 2308.5867 2308.3379 2308.0894 2307 .e406 2307.5913 2307.3389 2307.0940 2306.8335 2306.5806 2 306.3396 2306.0752 2305.81 84 2305.5579
2305 .'I525 2304.7959 2304.5393 2304.2788 2304 .O 183 2303.7620
-
-
-
0.0002 0.0002
0.0029 0.0023 0.0034 0.0006 0.0026
0.0020 0.0012 0 .OOI3 0.0018 0.0004 0.0022 0.0003 0.0003 0.0001 0.0006 0.0017 0.0001 0.0064 0.0020 0.0020 0.0102
0.0000 0.0022
0.0074 0.0003 0.0002
-
0.0015 0.0006 0.0020 0.001 1
38 39 40
41 42 43 44 45 46 47 48 49 50 51 52
53 54 55 56
57 58 59 60 61 62 63 64 65 66 67 68 69 70
71 72
73 74
75 76
77 78
2302.6 150 2302.3428 2302.0552 2301.7986
79 80 81 82
2301.2461 a
-
0.0026 0.0026 0.0120 0.0051 0.0027
An asterisk denotes blended lines which have n o t been used in the calculation.
77 78 79 80 81
82
-
404
The Journal of Physical Chemistry, Vol. 88, No. 3, 1984
D’Cunha et al.
TABLE 111: Molecular Constants for Carbon Disulfide (in c m - ’ ) Transition Upper S t a t e - Lower S t a t e
a.
a.
“
-
B I L 1 2 + BfIR112
0” x IO
0
v 1 v 2 v3- v I v 2 v3
8
12c32s34s 02OI -0OOO
2318.8224
f
0.0002
10 558.342
f
0.290
1.143
0.033
IO 590.947
f
0.290
1.179
031el -01 leO
2321.2382
f
0.0007
IO 567.451
f
0.470
1 . 1 4 2 f 0.010
IO 606.993
f
0.460
1.147”
0
2321.2383
f
0.0007
10 581.161
f
0.700
1.130 i 0.100
10 614 771 f 0.700
0 0 20 1-00 0
2811.4294
f
0.0030
10 492.384
f
1.800
1.006
f
0.028
IO 590.607
f
1.800
0.936“
lool-oooo
2172.7727
f
0.0002
IO 506.808
f
0.600
1.212
f
0.140
IO 590.975
f
0.600
1.190 f 0.140
2185.4679
f
0.0020
IO 827.040
f
0.260
1.376
f
0.160
I O 913.638
* 0.260
2134.8639 f 0.0020
10 830.762
f
0.900
1.133
f
0.060
10 913.425
f
0.900
I . i30?:
0.0010
IO 661.092
f
1.300
0.963
f
0.160
10 746.672
f
1.200
0.968 P 0.150
03l 1-01
f
f
0.033
1.147 f 0.100
12 32 s2
0 0 10 1-00 0
1.354
f
0.160
1 3 32 s2
lool-oooo 12c32s33s
2178.9520
lool-OOOO
f
~~
q(01’0) o f 12C32S34S =
7.778
1
cm-l and q ( 0 3 1 ) = 13.71 x IO-’
x IO-’
cm-’
constrained P(I5) 1
I
P(I2l I
I
P(9)
I
I
I
0201c00°0
03‘I t01’0
constants obtained for these bands are also included in Table 111. The corresponding basic observational data may be found in ref 12. In the second column of Table 111which gives the observed band centers, for the 11-11 band, the symbol vo is retained for the difference in the vibrational terms values G’(u) - G”(u) and so the observed band center comes out to be vo - B’l’2 B”l”2. This column is labeled as such because it also applies to the Z-Z bands where I’ = I” = 0. For bands already reported in the literature, the molecular constants from this investigation agree with the reported values within the respective uncertainties.
+
.-
i[
a n
-
2315.8
-
2316.4
2317.0 crn-l
Figure 1. A portion of the spectrum of 12C32S34S in the P branch region of the 02O1 000 and 03l1 0l1Obands showing the I doubling in the II-II band and illustrating the type of experimental spectra available for this study.
The measured line positions for 12C32S34S bands newly observed are given in Tables I and I1 and the molecular constants calculated from these data are summarized in Table 111. In addition, the in the 2800-cm-’ region and the 20°1 OOoO band of 12C3zS34S 13C32S2,12C32Sz, and 12C32S34S 10°l OOoO bands of 12C32S33S, have been remeasured in the present study and the molecular
--
Acknowledgment. The authors wish to express their deep appreciation to Dr. James W. Brault and R. Hubbard of the Kitt Peak National Observatory for their help in recording the Fourier transform spectra which formed the basis for the present work. Thanks are also due to Dr. W. M. Rutherford of the Monsanto Research Corp., Mound Facility for his interest and assistance in securing the highly enriched carbon disulfide. Registry No. 12C32S2, 75-15-0; 12C32S34S, 52774-62-6; 12C32S33S, 88106-10-9; 13C32S2, 30860-31-2. (12) J. Manheim, Ph.D. Dissertation, The Ohio State University, 1983.
