Infrared spectra of pentachlorofluoroethane, 1, 2 ...
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-------- Journal of Research of the Notional Bureau of Standards Vol. 50, No. 5, May 1953 Resear ch Paper 2 414 Infrared Spectra of Pentachlorofluoroethane, I, 2- Dichlorotetrafluoroethane, and I-Bromo-2-Fluoroethane Delia Simpson 1 and Earle K. Plyler Th e infra red absorption spect ra of pe ntac hloro Au or oet hane a nd 1,2-dichlol' otetra ftur o- et han e h ave bee n measured from 2 to 40 J.L. Sevo ra l band s were found in t he r eg ion from 25 to 40 }J-, which had n ot bee n prev iously inv estigate d. The spectrum of I-bromo -2- f1u or oet h ane has also been meas ured in the spect ral re gion f rom 2 to 40 }J- , a nd m a ny ban ds were obsen ·ed. A Ji st of the observed bands and t he fr eque n cy ass ignment s [or the t hr ee mol ec ul es ar e g iv en. In r ece nt ye ars much interest has been shown in the spectroscopy of fluorinat ed hydrocarbons. Gloclder and Sage, 23 fo], exampl e, have given tbe Raman spectra of S Uell compounds and Smith, Niel- sen, and coworkers 4 5 have given the infrared and Ram an spect ra of many fluorinated ethanes, along with fr equ ency assignments for some of them. In t hi s report we pr esen t sp ectra and assig nment s for t hr ee fluorinated hydro ca rbons, pentacblorofluoro- et hane (CCl3CC12F ), 1,2-dichlorot et rafl.uoro etbane (CClF 2CCIF2 ), and 1-bromo-2-fluoroethane (C H z BrCH 2F ) . The R a man spe ctrum of CCIF 2CClF2 ha s been report ed by Glockler and Sage (see foo t not e 2) a nd the infrared spect ra of CCl3 CCl2F and CCIF2 CClF 2 h ave been report ed by Smith and Nielsen (see footnotes 4 and 5). We have extended the infraI' d , spectra of the l ast t wo named mol ec ul es to 40 iJ. and present the spect rum of the t hir d in the 2 to 40 J.i. , l'ange. I The spectra of these co mpounds were obtained on a Perkin-Elmer mod el 12 C spectromete r. The 1)ri m used in the various spectral ranges \vere: 1 to 5 J.i., lithium AUOl'ide; 2 to 16 J.i. , sodium chloride; 14 to 24 iJ., potassi um bromide; and 23 to 40 J.i. , thal- lium bromide-iodide. Figure 1 shows the spectl'llill of CC1 3CC12 1 1' . It was obtained by comparing tbe absorpt ion of the I >compound wit h the absorption of ai.r. These obser- vati.ons were then reduced to the per cent transmit- tance of the compound. Figures 2 an d 3 pr esent the s pectra of CClF 2CCIF2 and CH2Br CH2F obtained in a similar manner. Th ese compounds were examined . in various states and under various experimental con- Iditions, the conditions being described on the figures ' and in the captions. Because these molecules do n ot form a closely re- I lated seri es of substit uted ethan es, it would not be expected t hat their spectra would show many simi- l arit ies. A general feature of the tllTee spectra is that mo st of the intense bands fall between 8 and 20 iJ.. In tab l es 1 t hrough 3 are given the observed infra- red bands, t he available Raman elata, and these fre- quency ass igLUnents for t he tl U'ee molecules. These 1 Newnh am College, Cambridge U ni versity. Cambridge, England. 2 0. Oiockler a ll d C hern . Ph ys.8,291 (1910). 3 O. O loek l 0J' a nd ('. tage, J . Chern. Ph), s. 9, :l8i (1911 ). " n. C. S mith, J . R c(' d:"Jiel sr ll , L. lL . nCrrynhll1 , 11. If. and R L. Hud so ll , N R L ReporL :l5(ii. 6 n. C. SlIIith,?o.f. Alp crt, H. A. Sawld ('l's , 0.1\1". Browl1, a nd X. B. :!\rornn, NItL Report 3924 . assignments were made on the basis of a nalogy with the assignments of closely relat ed s truct ur es which ha ve previously been st udi ed. crable 4 compar es these assignments for CH2Bl'CH2F with the wav e numb er ranges for lhe various v ibrations of t hr ee molecules. (CH 2Cl)2, (CH 2 Br )2, a nd CH2 BrCH2Cl. Th ese values are taken from tbe assignments of J. U. Brown and W. S. Sheppard, who hav e kindl y allowed the use of the r es ults of their work, which now await publi cat ion. Th ese foul' mol ec ul es liste d in ta bl e 4 are expected to exi st in two isomeric forms, trans and gauche. In this ta bl e are given the differences in going from the gauche to the trans form for individu al vibrations. 1'he assignments for CCl 3CCl2F and CClF 2CClF 2 were made in the sa me way by co m- paring their vibrations with related molec ul es. N1 FIG URE 1. I nfrared absorption spectl·U In oJ CCbCChF. The s pectr um of this s ubs tan ce, rio solid at room te mperat ure , was obtained by making a sa turated solution in OS2. In scrt A was o btained by mixing 1 part of the saturated sol ution with 4 par ts of CS,; in se rt U was obtained by mixing 1 part of the saturated solution with 20 par ts of CS2. ])o t tcrilines re present r eg ions of int ense a tmosphe riC a bsorption and of ahsoqnion of t.he soh'o nt.. FIG U R]" 2. Infmred ab s01' pti on spectrum of CC1F2CC1F 2• ' l'hi s spectr um is of the va por state. r rb e pressure was at mos pheri C, except for tbe in se rt s wbich were ob tained by removing s ome of the vapor. 'l.'be cell thick- ness employed f or th e d ifferent regions are m arked on the figure. Dotted lines are used in regions of inten se atmospheriC a bsorpt.ion. 223
Transcript of Infrared spectra of pentachlorofluoroethane, 1, 2 ...
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Journal of Research of the Notional Bureau of Standards Vol. 50, No. 5, May 1953 Research Paper 2414
Infrared Spectra of Pentachlorofluoroethane, I, 2-Dichlorotetrafluoroethane, and I-Bromo-2-Fluoroethane
Delia Simpson 1 and Earle K. Plyler
The infrared absorption spectra of pe ntachloroAuoroet ha ne a nd 1,2-dichlol'otetrafturoethane have bee n measured from 2 to 40 J.L. Sevo ra l bands were found in t he region from 25 to 40 }J-, w hich had not bee n previously invest igated. The spectrum of I-bromo-2-f1u oroet hane has a lso bee n meas ured in the spectra l region from 2 to 40 }J- , a nd m a ny bands were obsen ·ed. A Jist of t he observed bands and t he frequency ass ignments [or t he t hree molecules are g iven.
In r ecent years much interest has been shown in the spectroscopy of fluorinated hydrocarbons. Gloclder and Sage,23 fo], example, have given tbe R aman spectra of SUell compounds and Smith, N ielsen, and coworkers 4 5 have given the infrared and Raman spectra of many fluorinated ethanes, alon g with frequency assignments for some of them . In this report we presen t spectra and ass ignments for three fluorina ted hydrocarbons, pen tacblorofluoroethane (CCl3CC12F ), 1 ,2-dichlorotetrafl.uoroetbane (CClF2CCIF2), and 1-bromo-2-fluoroethane (CH z BrCH 2F ). The R aman spectrum of CCIF2CClF2 has b een reported by Glockler and Sage (see foo tnote 2) and the infrared spectra of CCl3CCl2F and CCIF2 CClF2 have been reported by Smi t h and Nielsen (see footnotes 4 and 5). We have extended the infraI' d
, spectra of the last two named molecules to 40 iJ. and present the spectrum of the third in the 2 to 40 J.i.
, l'ange. I The spectra of these compounds were obtained on
a Perkin-Elmer model 12C spectrometer. The 1)ri m used in the various spectral ranges \vere: 1 to 5 J.i., li thium AUOl'ide; 2 to 16 J.i. , sodium chloride; 14 to 24 iJ., potassium bromide; and 23 to 40 J.i. , thallium bromide-iodide.
Figure 1 shows the spectl'llill of CC13CC1211' . It was ob tained by comparing tbe absorpt ion of the
I >compound with the absorption of ai.r. These observati.ons were then reduced to the percent transmittance of t he compound . Figures 2 and 3 present the spectra of CClF2CCIF2 and CH2BrCH2F obtained in a similar manner. These compounds were examined
. in various states and under various experimental conI ditions, the conditions being described on the figures ' and in the captions.
Because these molecules do not form a closely reIlated series of substituted ethan es, it would not be expected that their spectra would show many similarities. A general feat ure of t he tllTee spectra is that most of the intense bands fall between 8 and 20 iJ..
In tables 1 through 3 are given the observed infrar ed bands, t he available Raman elata, and these frequency assigLUnents for the tlU'ee molecules. These
1 Newnham College, Cambridge U ni versity. Cambridge, England. 20. Oiock ler a lld ('.~age,J. C hern . Ph ys.8,291 (1910) . 3 O. O loek l0J' and ('. tage, J . Chern. Ph),s . 9, :l8i (1911 ) . " n. C. S mith, J . Rc('d:"Jielsr ll , L . lL . nCrrynhll1 , 11. If. C l flas~('n . and R L.
Hudsoll , N R L ReporL :l5(ii. 6 n. C. SlIIith,?o.f. Alpcrt, H. A . Sawld('l's , 0.1\1". Browl1, and X. B . :!\rornn,
NItL Report 3924 .
assignments were made on the basis of analogy wi th th e assignments of closely related structures which have previously been studied . crable 4 compares these assignments for CH2Bl'CH2F with the wave number ranges for lhe various v ibrations of three molecules. (CH 2Cl)2, (CH 2Br)2, and CH 2BrCH2Cl. These values are taken from tbe assignments of J. U . Brown and W. S. Sheppard, who have kindly allowed the use of the results of their work, which now await publication. These foul' molecules listed in table 4 are expected to exist in two isomeric forms, trans and gauche. In this table a re g iven the differences in going from the gauche to the trans form for individual vibrations. 1' he assignments for CCl3CCl2F and CClF2CClF2 were made in the same way by com paring their vibrations wi t h related molecules.
SNO~~IV~ N1 H19N313A~M
FIG URE 1. I nfrared absorption spectl·U In oJ CCbCChF. The spectru m of this substance, rio solid at room temperature, was obtained by ma king a saturated solution in OS2. Inscrt A was obtained by mixing 1 part of the saturated sol ution with 4 par ts of CS,; in se rt U was obtained by mixing 1 part of the saturated solution with 20 par t s of CS2. ])ot tcrilines represen t regions of intense a tmospheriC a bsorption and of ahsoqnion of t.he soh'ont..
FIG UR]" 2. Infmred abs01'ption spectrum of CC1F2CC1F2•
'l'his spectrum is of the vapor state. rrbe pressure was atmospheriC, except for tbe in serts wbich were obtained by removing some of the vapor. 'l.'be cell thickness employed for the d ifferent regions are m arked on the figure. D otted lines are used in regions of intense atmospheriC a bsorpt.ion.
2517G2-~3--1 223
1~:~~~~ 2 3 4 5 6 7 8 9 10 II 12 13 14 15
WAVELENGTH IN MICRONS 400 350 300 275cnr'
~Q025mm/
,/,---_ 0.2mm
: ,/
16 18 20 22 40
FI GU RE 3. Infrared abs01'ption spectTum CH2BrCH2F.
'I'his spectl'l11ll is of the liquid state, except for insert A, which was obtained by diluting with CS, in the ratio of 1 :20.
TABLE 1. Observed i nfTaTed freqttencies and band inteT pTetations oj CClaCC]2F
Two interpretations are presented , one assnming the existence of an unobserved band at 170 em-I ,
Frequency In ten - In terpretation In terpretation bv using s ity a 170 cm- 1 frequency
cm- I
264 m C - CI 315 m C - CI 400 s Cl- C - F 904 - 506 406 s CI - C - F 506 s C - C,
567 vw 880 - 315 400 + 170 406 + 170 625 vw 2 X 315 795 - 170 658 w 264 + 400 677 w 264 + 406 ] [ 506 + 170 689 w 1100 - 406 847 - 170
724 vs C - C], 795 vs C - CI, 818 w 506 + 315 2 X 408 847 s C - C], 880 In C - CI ,
904 In C - C], 954 w ------------------ 795 + 170
1009 vs 2 X 506 847 + 170 1041 w 724 + 315 884 + 170 1074 w ------------------ 904 + 170
1100 vs C - F , 1176 m 904 + 264 1215 s 904 + 315 1225 s 724 + 506 1256 m 904 + 400 904 + 406
1267 m 847 + 506 1100 + 170 1310 vw 904 + 506 1350 vw 847 + 506 1399 vW 904 + 506 1418 vw 1100 + 315
1825 w 1100 + 724
{ 2 X 795 + 506
2088 w 2 X 847 + 400 724 + 847 + 506
2179 w { 3 X 724 2 X 1100 2 X 880 + 400
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TABLE 2. Observed i nfrared and Raman fre quencies and interpretations of CC11"20C1F2 T he Raman frequencies are those of Glockler and Sage (see footnote 2 of text )
Infrared In te n- Raman Intcrprctation
frequ ency sity frequen cy Trans Gauche
171. 4 -------------------- C- 0 1o 207.4 0 - 010 C-Ci. 253. 1 C- CI.
310 m 309. 5 -------------------- C- F2 . 325.7 C- F2
360. 0 [ C1"2 r 399. 9 CF2 w
415 m ------- - CF2 r
437 s -------- CF2 w
442. 5 s 443. 9 -------------------- CF2 •
497 S 497. 7J ------------- - ------ [ CF2 r 503 s 503.4 ----------------- - -- CF. w 542. 8 CF2 t
55g m 556. 5 [ C1"2 t 734- 171 -------------------- 1053 - 498 583 w -------- CF2 t
6J7 vs -------- CF2 • 676 vs 677. 0 ------------------- - C- O, C-CI,
699. 7 C- CI, 723.4 C- C,
736 vs 734.1
772 w -------- 415 + 360 437 + 325 [ 498 + 310 796 w -------- 437 + 360 498 + 310 847 vs -------- C- OI, 883 m -------- 1138 - 253 2 X 443 1053 - 171 921 vs 914. 7 ---------- -- -------- CF,
942 w -------- 617 + 325 360 + 583 498 + 444 503 + 444 1007 '" -------- -------------------- 2 X 503
1043. 5 732 + 325 617 + 437 734 + 310 1051 vs 1055. 9 ------------- - ------ OF,
1063. 7 CF,
1111. 6 700 + 415 847+ 253 677 + H4 1138 vs -------- CF,
1172.5 CF, 1185J vs CF, 1192 --------
1227 111 -------- -------------------- CF, 1267 m 1269. 6 -------------------- CF, 1316 w -------- 700 + 617 1357 w [1053 + 310 2 X 677
-------- --------- - ---------- 92& + 444 1435 w -------- 1188 + 253 1268 + 171 1504 w [1188 + 325 1184 + 360 1053 + 444
-------- 1064+ 437 ------------ -- - - -- - -
1675 w -------- 1064 + 417 1138 + 543 1227+ 444 1727 \V 1118 + 543 [1053 + 677 1227+ 495
-------- 1227+ 503
1842 w -------- 1138 + 700 2 X 921 1887 w -------- 1188 + 700 2110 vw -------- -------------------- 2 X 1053 2222 w 2'159 w -------- ------------------- - 2 X 1227
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TABLE 3. Observed infrared fre quencies and interpretations oj CH 2BrCH 2F
-In terpretation
F requency In ten---------------~~---------
sity I T rans
I Gauche
cm- I
264 m C - Xo 338 m
~--------------------- C - Xo 451 s ---------------------- C - Xo 574 s ----------- - ---------- C - CI, 679 s C-Cl,
776 "'IV CH2 r (ro cking) 822 s ----------- - ---------- CH 2 r 847 "r ---------------------- 1182 - 338 879 " 'iy
897 V \V -------------------- - - 2 X 451
943 s --------------------- - CH 2 r
1006 vs CH 2 r C - F , 1020 m ----------- - ---------- C - C, 1060 n1 C - C, 1075 s C-F,
1182 s ---------------------- CH 2 t 1218 W CH2 t
1229 S CH 2 w
1279 vs CH2 t CH 2w 1333 'i" CH2 w
1389 vs ---------------------- CH2w 1422 vs ---------------------- CH20 1461 S CH20 1529 V,\" ---------------------- 1182 + 338 1618 w ---------------------- 1279 + 338
1639 w ---------------------- 1182 + 451" 2 X 822 1845 w 1060 + 776 1075 + 776 [1020 + 822 1006 + 943
1389 + 451 1279 + 574 1890 m 1218 + 679 2 X 943 1953 w 1279 + 679 1389 + 574 943 + 1020 2008 w [2 X 1006 1229 + 776 1182 + 822 2 X 1006 1333 + 679
2066 w 1006 + 1060 1279 + 776 2123 vw 2 X 1060 1182 + 943 2172 w ---------------------- 1006 + 1182 2226 m 1006 + 1218 1006 + 1229 1279+ 943 2428 w 2 X 1218 1422 + 1006
2458 m 1461 + 1006 2 X 1229 1279+ 1182 2534 ". 1461 + 1075 2611 V\V 1333 + 1279 1422 + 1182 2660 w 2 X 1333 1389+ 1279 2725 s 1461 + 1279
2756 m 1333 + 1461 2832 m ---------------------- 2 X 1422 289~ s 2 X H61 2949 s CH , 4 mod es CH , 4 modes 2976 s
3125 w 3246 w 2976 + 264 3731 V \ V 2949 + 776 3817 V\Y ----------------------3861 vw ---------- - ----------- 2949 + 822
3921 V\V ---------------------- 2976 + 943 4013 \V 2949 + 1060 4058 111 2976 + 1075 4235 w 2949 + 1279 2949 + 1279 4290 m 2949 + 1333
4329 w --------------------- - 2949 + 1389 4354 In
I --------------------- - 2976 + 1389
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TARLE 4. Compw'ison oJ the j1"equencies below 1,500 C1I1 - 1 oJ (C II 2C I)" (CI1 2B r)" awL C I:-12BrC II , !
The n i.lu('s li sted for X:'l· an" the range of value's for t.hese throe compound s, those listed a ftC'r Br·F arc the values for Cl12Rr ClJzF . R a man yalues are iIlCill<i C'ci wlwrc fw ail able . "Not obscl'\'cd" means no infrared valuC's ha\'C' boen reported .
-Frequencies below 1,500 cm- 1
CH2 CH2 wag
Trans A" i l ' Bu , A' Tmns A" A' Bu , A'
x-y _______________ 1438 to 1448 1439 to 1453 X-Y _ ------------ 1250 to 130] 11 92 (,0 123 1 Br-1" ___________ ___ 1461 1461 B~F _______________ 1333 J229
Gauche A,A B,A Dauche A , A B, A
X-1~ ______________ 1419 to 1433 1419 to 1433 X-Y __ - ---------- ]278 to 1312 124810 128:3 B r-F ______________ 1422 1422 Br-F _______________ 1389 1279
CH 2 LlI'is t c rT, rock
Trans Au, A" B" A" '/'mns ! A ll , A" I 11" A"
X-y ____________ -- 1095 to 1124 1250 to 1265 X-y ____ - - 745 to 77:3 I
93:3 (0 992 Br-F ______________ 12 18 1279 Br-F ___ 776 1006
Gauche A,A B,A Gauche I A, A I 13, A
X-Y ___ ____________ Not observed 1105 to 11 45 X-V _ ---- --- __ -- ___ I 899 (0 944
I
834 to 880 Br-]" ______________ Not obse rved 1182 Br-F________ _ ___ 943 822
I
C- Halogen, C- Halogen
Trans A " A' Bu, A' Trans
I A " A' B ,,, A '
X-y _______________ 657 to 750 586 to 7 J1 X-1'
------1 190 to 302 Kol observed .
Br-F ______________ 1075 679 13r-F ______ - 264 Ko( ob~e r ved.
Gauche A, A B, A Gmtche A, A B, A
X-y _______________ 55 1 to 665 583 to 678 X-V ---- ------- __ I 272 to 327 355 to 4 12 Br-F ______________ 1006 574 B~F _______________ 338 451
!
C- C, Tors ion
Trans A" A' Trans Au, A'
X-y _______________ 934 to 992 X-y ___________ ____ Not observed . Br-F ______________ 1006 Br-F _______________ Not observed .
Gauche A,A Dauche A,A
X-y _______________ 894 to 943
1 X-y _______________ Not observed.
Br-F ______________ 943 Br-1" __ _____ ______ __ Not observed .
VVASHINGTON, January 5, 1953.
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