j

Indian Journal of Pure & Appli cd Phys ics

Vo l. 3X. Fchruary :WO(). pp. (ll) -X('

Vibrational analysis of l-chlorohexane

*Neena Jagg i & R M P Jaiswal

Dep,lrtmelll of Phys ics . Kurukshct ra Uni vc rsity. Kurukshetr;1 136 II ()

Recei vcd I Deccmher 11)91): acccptcd 3 I Dccembcr 191)1)

In rrared and Ram,rn spcc tra of I -chlorohcxanc liquid at amhient tcmperaturcs ha ve heen rcportcd c; lrli er. However. in thc

ahscnce of normal coordi natc calculat ions. thc assignmcnts o f frcqucncics werc onl y tentati ve. A detai led analysis and assignmcnt

of the vihrational rrcquellcies of thc spcc tra w ith thc aid of normal coordinate calcu lati ons for the fi v'2 prohahle cOllforl1l;ltions

of 1- chlorohcx; lIlc molecule prcsellt in the lIeatliquid havc hecn reportcd. Thi s has nccess itated mOllifi c;lli ons inmallY prcviou sly

suggested assignmcnt s.

I Introduction

Vibrati ona l spectra of a number of sa turated hyd ro­carbons ha ve been obta ined and interpreted with the aid or normal coordinate calculations over the last three decades . These includes l1-alkan es l~ , branc hed al -

, ~ --l ' . 'l

kanes- , cycloa lkanes and substItuted cycloa lkanes-. Vihrational anal ys is of a se ri es of n-alk ylchl orides also has heen made by Snyder and Schachteschneider"' by recording the infrared spectra at liquid Nl temperatures and carrying out normal coordinate ca lculations . But these authors"' ha ve recorded onl y in fra red spectra in so lid phase tn show the presence of two conformers (IIWIS and gU llche ) and have not given liquid phasc Raman spectra of I-chl orohexane. A preliminary analy­sis or the liquid phase infrared and Raman spectra of I-ch lorohexane was reported earl ier by our laboratory workers" . However. in the absence of normal coordinate ca lculati ons for thi s molecule the assignments of vibra­tiunal frequencies were only tentati ve . As such, a de­tail ed vibra ti o nal anal ysis a nd ass ig nm e nt o r frequencies of the observed spectra on the basis or normal coordinat e ca!culati ons 1'0 1' all the fi ve probable conformers ex pected to be present in the neat liquid or I-chlorohexane are present ed here forthe first time. This is al so aimed at ascertainin g the presence of these ro­tamers in the liquid phase.

2 Calculations The ex perimenta l de t ~tils of recording the infrared

and Raman spectra or I-chl orohexane ha ve been given elsewhere". S ince the prev iousl y reported spectra we re

':'Departmcnt or Ph ys ics. t Ini ve rsi ty Co ll c.!,!e . Kuruk shctra LJ lli vCl's it y . Kuru~ s he t r; ,

recorded in the liquid phase at ambient temperatures, these were the superpositi ons of the spectra due to all the conformers of the molecul e.

The calculations were made for fi ve most prohable conformations of the mo lecule . As is found in se ver,t1 hal ogenated alkanes)'?, the most stab le (I ) of these struc­tures should be that in which CI atom is co- planar with the C-C skeleton of the molec ul e as shown in Fig. l . Thi s belongs to C, symmetry and is ca lled 11'017.1 CO l1rOrl11 :t­ti on, while all the other structures (II -V) possess ( '1

sy mllletry. In the conformation II ca lled gOl/ ch e. the CI alom is lyin g above theC-C ske letal plane (F i .~.2). whi le

Cl "'"y~': 145 H10 H ~

( - C ::: 1.7: l.. c· C :.1 .51. 8. C - H e 1.0" Z

I,LL 801·1[1 -'r-lGl E 5 0 IVY.!. 7

Fi g. I - Strllcture or I-chlmollexanc ( I )

C ~ q - l .7 1 t.. C = l - 1 'J .• ! C-H:: ' . O~/l.

AL L 80l·1f) A1·J Gl E ~~ - 1 0~1 ~ 7

Fi .!,!. 1 - Structure ()r l -clll or<Jllex allc t il )

70 INDIAN J PURE & APPL PHYS, VOL 38, FEBRUARY 2000

in the conformation III, the methyl group attached to Cs atom has been rotated about C4-CS bond to occupy the position of HI) . In the remaining structures IV and V, the CI atom is above the C-C skeletal plane and the methyl group attached to C; is rotated about the C4CS bond to occupy the positions of Hl) and HIO respectively.

Snyder and Schachtschneiders and also Jaiswal, Garg and Crowder6 have shown that while the spectrum of the un-annealed deposit of I-chlorohexane at liquid N2 tem­peratures indicates the presence of trans and gauche conformations both, the well annealed sample consists of the trans form only. Therefore, assuming that the structure of I -chlorohexane as shown in Fig. I with Cs symmetry as the most stable one, normal coordinate calculations were done first for this geometry of the molecule by transferring the force-field from 2 chloro-4-methylpentane7 and dimethylhexanes4

. It was found that most of the calculated frequencies of the conformer I fitted well with the prominent bands of the liquid phase infrared and Raman spectra of the molecule confirming that it is the most stable conformer: Therefore, refine­ment of the twenty two force constants of the General­ized Valence Force Field (GVFF) was carried out for the conformation I to obtain the best fit of the calculated frequencies with the observed bands of the spectra with an average error of 7.2 cm - I . This refined force field (Table I) was used to compute the vibrational frequen­cies for the remaining four conformers of the molecule.

Computer programs written by Schachtschneiderl.x were util ized for the calculation of kinetic energy matrix (GMAT) and for the solution of the vibrational secular equation (VSEC). The force constant matrix was set up for the molecule using the program written by Crowder and Potter') . Latest version of these programs was pro­vided by Crowder. The molecular parameters used in these calculations are C-C = 1.54 A, C-H= 1.09A, c-c I = 1.77 A and all the bond angles are assumed as

I09.4r.

3 Results and Discussion The n-chlorohexane molecule in conformation I has

C symmetry and two species of vibrational modes a'

and a", whereas the conformers IJ-V have C I symmetry and only one species A. All the observed bands of the molecule in the infrared and Raman spectra could be con'elated with the calculated frequencies for the above mentioned five conformers. The correlation of the cal­culated frequencies for all the five conformers with the observed bands and their assignments to various modes of vibration have been given in Table 2. Also it is noticed

from Table 2 that there are celtain observed bands which could be assigned to only one conformer. Five infrared bands at 1238, 1116, 915, 826 and 440 cm -I and four Raman bands at 1116,821,385 and 265 cm- I correspond to conformer I only. Four infrared bands at 1082,932, 904 and 473 cm- I and three Raman bands at 1023, 475 and 365 cm- I are assigned to conformer II only . Simi­larly two infrared bands at 840 and 565 cm - I and two Raman bands at 1206 and 340 cm -I belong to conformer III only. Three infrared bands at 1202,994 and 416 cm- I

and one Raman band at 290 cm- I are correlated to rota mer IV only. Finally, two infrared bands at 803 and 610 cm- I and two Raman bands at 1050 and 807 cm- I

belong to conformation V only. These observations justify the existence of all the five conformers of the molecule in the liquid phase at ambient temperatures.

The C-H stretch vibrations for all the five conforma­tions have been calculated in the frequency range 2995-2855 cm- I

, mostly as pure modes (Table 2). These have been correlated mainly with the observed Raman bands because the infrared bands in this region appear as broad bands. The next lower frequencies calculated for the CH, and CH2 deformation modes in the approximate region 1467-1369 cm- I have been correlated in the most cases to observed bands (Table 2).

The next lower range of frequencies consists of wag­ging and twisting modes in the range J337-IIOO cm·· I

.

These are mostly mixed modes. Below this up to aboul 550 cm- I are spread CH2 rock, C-C stretch,C-CI stretch and CH2-CI rock modes. The C-CI stretch frequencies in conformations I and III (in which CI atom lies in the plane of the C-C skeleton) have been calculated at about 650 cm- I

, while in the remaining conformers this mode has been calculated at about 600 cm- I

. This explains observation of only two distinct bands in this region in the infrared spectra of the molecule. Also while the higher frequency band appears very strongly the other band is much weaker than this. In Raman spectra also while the higher frequency band is observed very strongly, the other one has not appeared at all (Table 2).

4 Conclusion As a result of present normal coordinate calculations

many of the previously reported assignments of vibra­tional frequencies have been modified. Existence of more or less five distinct conformations in the liquid phase of the molecule have been demonstrated . The calculated C-C1 stretch frequency for the conformers I and III where CI atom lies in the plane of C-C skeleton has higher value than for other conformers. The lower

JAGG I & JASIWAL: VIBRATIO AL ANALYSIS OF I-CHLOROH EXANE 7 1

Tahlc 1 - Forcc constan ts for I -chlorohex<lnc (ClC6HI ~ )

Force constants Group Coordinate(s) in volved Atoms( s) common Vai lic " Strclch

1\ ,- CH I C- H 4 .75 7

" '<1 CH ~ C- H 4 .5~~

KI< C-C C-C .'-')().:)

" ',dClI C-C-CI C-C 4 .2Xh

K CI C-CI C-CI 3.204

Slrctch-s tretch

F,- CI-h C f-I.CH C - O.OOX

/:<1 CH" C f-I.C1-1 C - 0.017

/.'J< C-C-C CCCC C - (l.(I24

FI<c I C-C-CI CCCCI C () 7:10

Bend

/-I" Cf-h I ICH 0.54.'

/-I II C-CH, CCH 0621

1/,) CH ~ HCH (1.)07

I-Iy C-C f-b -C CCH 0,4 7X

1/: C-Cl-I -C CCI-I U,47X

I-IH CHCI ClCH O.SD

/-1"1 C-C-C CCC 1.160

I-I=- C-C-CI CCCI O.:'i46

Stretch-hcnd

FI<~ C-C1-1 I CCCCH C-C O.Y'i4

FI<'I= /:I{'c, C-C1-11.2-C CCCC H C-C OS()()

I-"J<Y= /-'Rc, C-C H I 2-C CCCC H C O.O7()

FI<'ol= FI<'~ C-C-C ceccc C-C (l,:I -l 1

I- J<=- C-C-CI CCCCCI C-C O.07S

I-" ' I~ C-CHCI-C CCI.CC H C O.22h

Felli C-CHCI-C CnClCH C-CI () .~:i~

I- eifol C-CHCI-C CCI.CCC C - O.22()

I- el=- C-CHCI-C CC I.CCCI C-CI O . .'ilJ2

Ik nd-hcnd r 1-'1 \ C-C H.l CC H.CCH C-C 0 .0 I ()

Fy C-C H I.2-C CCl-I.CCH C-C - O.O()X

I-"y = /-'~ C-Cl-I 1.2-C CC f-I.CCH C-H - 0.( )54

F"I eC l CCCCCC C-C - 1l.(J.:) I

I-'=. C-CCI-C CCCI .CCCI C-CI - i),11I)7

F~(J C-CHCI-C CnClCH C-CI (U17 .

./' '1=.1' yc, =.I' IX; CH 12-CH2,) HCCCCHl transl C-C 0. 127

l y=/ yc,=llli';' CH J2-CHn HCCCC Hlgauchel C-C - 0 . Il.'i 4

./' Il fOl~t' 1\') CH ~ -C-C-C(C H ~ ) 2 CCCCCH Itrans I C-C 0 .070

F~ I j(' I~/~ II,) C I-h-C-C-C(CH ~)2 CCCCCHlgauche] C-C - O. 14X

.I' ,,,= .1' "'0 C-C-C-CC2 cCCCCqtransl C-C 0 .040

t' "I=- C-C-C-CI CCCCCCllt ransl C-C (1.()4 I

I~ "I=- \.-C-C-CI CCCCCCl lg;!uchel C-C - 0.02,:)

Torsioll

1/ , C-C C-C O.OO(J .-

':' St relching cOllstant s are in unil s or Illdyn A - I. stretch-bend const,lIl1S are in units of Illdyn A rad- 2

72 INDIAN J PURE & APPL PHYS. VOL 38. FEBRUARY 2000

Tahle 2 - Ohserved and calculated wavenumbers and approximate potential energy distribution for l -chlorohexane

Ohserved frequency (cm- I )

-------------------------------IR·.

I- Chlorohl'X({I1C'I Cs) a'

2995

2X65

2X65

1462

1445

1432

1432

1372

J:\ I 0

1277

1238

1178

1056

1036

9X5

l)52

()51

440

RAMAN

2995

2912

2'{1,77

2'{1,65

2X65

2855

2855

1452

1444

1436

1436

1375

1340

1305

1180

X90

752

65 1

3X5

265

Calculated PED

frequency (cm· l )

2995

2914

2870

2860

2864

2'{1,57

2X54

146X

1452

1444

1439

1433

1422

1369

1336

1310

I 2 '{I, 0

1232

11 76

I05X

1038

979

959

892

747

652

443

388

250

1'{I,9

X5

(% )"

CH3as(99)

CH2Clss(99)

CH3ss195)

CH2ss( 40),CH2ss(30).CH2ss(22)

CH2ss(38),CH2ss(3I). CH2ss(20)

CHzss(39).CH2ss(30).CH 2ss(22)

CH2ss(39).CH2ss(33) .CH 2ss( I X)

CH3a8(38) .CH,s8( 17). CCs( 14).CH2<1J( 13)

CH,a8( 48).CH,s8( I 0)

CH28( 13).CH2S8( I I ).CH28( I I )

CH28(25),CHz8(20) .CHz8( I X)

CH28(32).CH28(22).CH28( 17)

CH28(22).CH28( 14 ).CH28( 12)

CH28( 19) .CH2m( 14).CH2m( II ). CH28( II )

CH2m(31 ).CH1S8( 131.CH2m( 12). CH 28( I I )

CH2<1J(47 )

CH2m(37) .CH, s8(34 )

CH2C1m(35).CH2m( 14)

CH2m(68)

CCs(35).CH2Clm(21)

CCs(28).CCs(28).CCs( 16)

CCs(44).CCs(21)

CCs( 42).CCs(25).CCs(22).CH2m( 19) .CH, r( 13)

CCs(4 1).CHv(24).CCs( 12).Ccs( 10)

CHv( 42).CH2m(33)

CCls(83).CI'hClw(26)

CCC8(29).CCC8( 17).CCC8( I ))

CCC8(39) .CCC8( 18).CCC8( 15). CH2m( 12). CCC8( II)

CCC8(36).CCC8(24).CCs( 14).CCls( II)

CCl8(54).CCC8(32)

CCC8(38),CCCI8(37).CCC8(25) .CCC8(20). CCls( II)

... (Conld )

•

lAGG] & .IAS]WAL: VIBRATIONAL ANALYSTS OF ]-CHLOROHEXANE

Tahlc :'.

Ohscrvcd I"requency (C Ill- I )

II{ RAMAN

" :1

:'.<J'J.'i 29<)5

:'.<)1)5 2995

2957

21):lX

29:1X

29:1K

14:,)(,

I I X5

117X 1171

1111, 1116

I05()

1002

()1 5

XI:') X2 1

no 72X

557

/- ("h!urrllI,'.\w/(' 1/ ( ('I )

:2<)<)5

2<)<)5 21)1)5

2()()5 21)XX

2957

29:1X

21)3K

291K

Calcu laled

I"requency (C lll - I )

2995

299:1

2949

2945

294 1

21)3X

111) 1

1170

1141)

11 27

1060

1000

906

nl

51){)

55:1

226

4K

42

27

17

:21)95

2995

2992

2949

2945

2941

291X

(Conld) ...

C I-1:1as(99)

C H2Cias(99)

C H2as(6).CH2as(36) .C H2'IS( 13).CH2as( 1:1)

C Hps(36).C H2<1S(36).CH2as( 13).CH2<1S( 13)

C H 2as(6).CH 2as(36) .CH2as( 13).CH2<1S( 1:1)

C H2as(6) .CH2as06).C H2as( 13).CH2as( 13)

C H,ao(96)

C 1-I 21(4 1 ).CH2CIt(25)

C I-I 21(56).CH, r( 12)

C H21(46).CH21(36)

0-l2I(46).C H21(36)

CH 2CiI(22).CH 2t( 19).C H2r( 14 ).CH2r( 12).Cl-br( I I )

Cl-br( 19).CH2CIt( 19).Cl-hrr I S) .CH 21( 14)

C I-hCIt(23).CH2r(22) .Cl-12C lr( 17) .C I-I 2r( 14)

Cl-br(3 1 ).C H2Cir( 19).CH21"116).CH2r( II )

C 1-I 2r( 47).C I-I 2r( 3X)

CI-I2IDO).CH 2r(63 ).CH 2L(20 )

CH 2Cir(63).CH2r(62).CH 2L( I k ).CH2CIt( 14 )

C H, 1(95 )

CC1(38).CC1(29).CH2Ci1(2 1)

CC1(46).CC1(23).Cl-12C I1(22)

CC1( 42).CH2CI1(25) .CC1(24)

CC1(35).CH 2Ci1(30). CC1(20)

CI-has(99 )

C H, <1s (99)

CH 2CI<1s(99)

Cl-bas(37) .CH 2as(36).CH 2<1S( 14).CH 2as( 12)

C H2as(6).CH2as(34).CH2as( 16).CI-I 2as( 1:1)

C H 2as(3R).CH2as(:l6).CH 2as( 15).CH2as( I I )

C H 2<1S(36) .CH2<1s(:l5).CH l as( 15).CH2<1S( 1:1 )

.(eonld)

74 INDI AN J PURE & APPL PHYS. VOL 38. FEBRUARY l OOO

Tahlc 2 (Contd ) ...

Ohscrvcd frequency Calculated PED (cm- I ) frequency (% )"

(e rn - I)

IR RAM AN

29 12 29 12 C H2C1s(99 )

2877 2870 C H,ss(95 )

2X65 2X65 1864 C H2ss(38 ).CH 2ssi34) .C H2SSI I (, I

2X6) 2X65 2860 C H2ss(36).CH2ssi3 I ).C H ~ss( 19 )

2855 2X56 C l-l2ss(3l)).CH2ss133 ).CH :> ss( 17 )

2855 2854 C H2SS (36) .C H2ss(34) .C H 2SS( I (').C I-l2ss( 12)

14(,2 1467 C H, ab(40).CH,sb( 17).Cf-1 2W( 13).CCs( 13)

1456 1455 C H)<Ib(96)

1452 145 1 C H, ab(5 2) . CH,sb( 13)

144") 1444 1442 C H :>b(26) .CH2b(2 1)

1.1, '1 143(, 1435 C H2b(29).CH2i5(20l

I-F 2 14:1(, 143(J C l-l2b(()3). reci.( 13 )

1420 C H20(2 6).Cf-lzb( I 8 )

137:: 1)7") 1:16l) C H2b( I X).CH2W( 13).Cf-ho( 13). C H20( 12 )

1.,4(, Ll4,,) 1:137 C H2W(27). C H2W(24). Cf-h soC II )

1:1 10 130") 1302 Cf-lzw(24). C H2W( 16). C H2 C lw( 12)

1290 1294 C H2W(25). C H2 Clw(22).Cf-12W( 13)

1177 1267 1279 C H2W(37 ).CH,sb(35 )

IIX5 I I)-I() II 87 C H2w(3 1 ).Cf-bt (2 1). C H2 C lt( 14)

117:1 1171 C H2t(55) .C H1r( II )

11")0 Cl 12t(45 ).CH2t(3LJ)

1129 Cf-l l l(4X).Cf-jztI33).CH2t( 10 )

1098 C H2t(26).CCs( 12)

IOX2 1076 1083 CCs(22).CCs( 16) . C H2t( 13).Cf-1? C lt(21 ). CC\( 10)

1065 1061 Cf-I}CIt( I LJ) .CCs( 14 ).CCs( 13)

102.1 1029 CCs(34 ).CCs(3 l )

I()IX 1002 1006 C H2r(2 1 ).CH, r( 16) .C H2r( 13).C l-br( 12)

%5 % 3 CCs(30) .CCs(28)

l)~2 942 CH cw(23).CH2C1t( 1l)).CCs( 16 ).CH:\I·( 1.1)

')()el 80S CCs(27).C H, r(20).C I-b r( 10 )

8X2 C II 2r(28).CI-I 2r( I O).CCs( 10)

7XO 71\<) C I-br(3 1 ).CH2r(27). Cf-b Clr( I X)

.. . (C(lnt .i )

JAGG I & JAS IWAL: VIBRATIONAL ANALYSIS OF I-CHLOROH EXJ\NE 75

Tah le 2 (Contd) ..

Ohse rved rrequency Ca lcul ated PED (C lll- I ) rrequellcy ('M,)"

(cm-I )

IR RAMAN

756 746 C l-l v(3 1 ).C 1-1 20)(3 I ).CCs(23)

7'2-: 72'11, 728 CI-I2r(37).C I-I2r(27).C l-l l C1r( I ~:)

()5 1 65 1 648 C1-I2r( 47).CI-I2C1r(3X)

flO I ()OO CCls( 1(3).CI-i2C lw(26)

589 CI-\]r(7 1 ).C l-l v( 63).C\-\]1 (2())

.+7:1 475 463 CCC8(26). CCC8(25). C I-I 2W( 10) >

365 356 CCC8(26). CCC8(24). CCs( I (I)

326 CCC8(38). CCC8(24). CCCI8(20)

226 CH:\1(95)

172 CCCl8(7 1 ).CCs(20).red ( 14)

132 CCC8(43) . CCC8(4 1). CCCo( IX). (CC8( 10)

45 C(1(51 ).CCr( 16 ) CCCl ( 16).C I-I 2Cir( 1.+ )

3'11, CC1(45) .CI-I 2Cll ( 19).CC1( 17).CC1( 15 )

2 1 CI-I 2C1r(61). CC1(32)

17 CC1(62).CC1(30)

I - C!i/owlwxw/(' III (C I)

21)<)5 2905 2005 CI-I , <ls(96)

2<)1)5 2095 2994 Cl-has(96)

21)1):; 29'11,'11, 2002 CI-I 2Cla5(99)

2<)57 2940 CI-\]<ls(39 ).CI-I2<1s(3 X) .Cl-l l <1S( 14)

2057 2945 CI-11C1S(S2).CH2as(27).CI-I 2as( I I )

.". 2057 2943 C H 2as( 3 7) .CI-I 2as( 32 ).CH 2; \S( :Hl) J

21) 3'11, 2930 CI-i2as(50).C I-I2<1 S(27).C I-I 2ase I )

20 12 29 13 CH2Clss(99)

2'11, 77 287() ( 1-l)ss(96)

2X()) 2'11,65 2864 CI-i2ss(47).C I-I 2ss(3 1 ).CH2SS(2 1)

2'11,55 2850 CI-i2ss( 4 7) .CI-I ]SS( 47)

2'11,:;5 2)158 0 12SS(94)

2'11,55 285'11, C H 2SS( 5 2).C 1-1 2SS( 27).C H 2SS( 20) -...

1-1()2 1467 CH, a8(34).C l-h s8( 15).CH1W( 12) .CCs( 12)

145() 1455 CH1a8(05) ... (Con ld)

76 INDIAN J PURE & APPL PHYS, VOL 38, FEBRUARY 2000

Tah le :2 (Cotl ld ) ...

Observed frequency Ca lcul ated PED (C lll - I ) frequency (%)"

(C Ill - I)

IR RAMAN

1456 1453 CH, <10(53)

1445 1452 1446 Cl-bo( 17). CH 20( 16). CH20( 12)

1444 143<) CH20(28). CH 20( 13). CH20( I ! )

1432 143() 1432 C I-120(47)

14 14 CH20(39).CH20( I X)

un 1375 136<) CH20(24).CH20( 16) . CH20( I J)

I 34() 1340 134 1 CH2w(3 8) .CH ,50(23)

1:l I O 1305 1307 CH2W(62)

1267 1261 CH 2Clw(21 ).CH2W(2 1 ).C H,sl'i( 14 )

1206 12 J2 C H2W( 19).CH2W( 13) .C I-12w( I l).CH2l( I 0)

II X5 I I X() 11 90 CH2t( 43 LCH2C1 t(25)

II X5 I I XO II X4 C H2C lw(22).C H2W(21 ).Cl-121( 15 ).C H2W( 10)

11 64 CH2t(36 ).CH2w(35 )

11 53 C H2t( 45) .Cl-h t(25)

11 3 1 CH2l (60).C H2l (26)

107() 1074 CCs(25).CH2r( 15).CH, r( 14) .C H2C1w( J 0)

1065 1068 C H2C1l( 16).CCs( 14).CH2r( 13).C H2t( 13).CH2r( 10)

I ()3() 10:14 CCs( 17).Cl-bCl t( 14 ).CI-b l ( I I )

IOIX 10m 1006 CCs(55).CCs(24) .CH2C1w( I (li

')X5 t)l)() <)X4 CCs(44).CCs( II )

lJ52 956 C H2r( J 5).CCs( 15).Cl-bClt( 12;

Xt)O XlJ5 C Hv( 17).Cl-12C1 t( 16).CCs( 12;

X()X X6lJ CCs(39).CI-12w( 16).CCs( 12).CCs( I O).Cl-12t( 10)

X40 X29 Cl-br(24).CH2C lr( 16).C H2r( 14). CH)I( 13)

752 750 CHv(25).C H2W(2 J ) CCs(22).CCs(20)

DO nx 733 CH2r(42)_CH2r(25) .CCs(4 1)

()I ()5 I 650 CCls(84 ).Cl-12C1w(26)

()() I 601 CHl r(66).C H2r( 5X ).CI-b t(23)

:'i():; 557 553 C I-bCl r( 63 ).Cl-l2r(62)

-1:;5 454 4M CCCO (30).CCCI0(2()

34() 335 CCCO(40) .CCC8(22).CCCl8( 16)

324 CCCO(::;O) .CCC8(20).CCC8( 13) .. .IContd )

JAGGI & JAS IWAL: VIBRATIONAL ANALYS IS OF I-CHLOROH EXANE

T ah le :2

Ohserved frequellcy (C Ill - I )

--------------------------------IR RAMAN

I - Ch/omlwwlI(' I V(CI!

2995 2!)95

29')5 2995

2')l) 5 29XX

2!)57

293X

2,)3X

29]X

2') 12

2Xn

2X(,:) 2X(,:)

2X55

2X55

2X 55

14()2

145('

1452

1444

14:12 143(,

14,\2

1:<72 137')

1:<"+6 1340

13 10 1305

12!)()

Ca lculated

frcqucncy (C Ill- I )

232

176

102

45

4 1

25

16

2995

2994

2992

294')

2')45

2943

2939

2912

2R70

2R63

2R5R

2X5X

2X54

14()7

1455

1452

1443

1437

142')

14 13

1370

1337

I ] 1\

1294

1226

(Contd ) ..

PED (%)"

CH, 1(65),CCs( 15).CCls( 13)

CCClo(32)_CCCo(26) .C H, 1(22)

CCClo(47).CCCo(33).CCls( 14)

CC1(3!))_CC1(34). Cl-hCl1(24 1

CC1(42),CH2C I1(33) ,CCt( 13)

CC1(53).CH 2C11(44)

CCt(5 1 ).C H2C1t(42)

C H, as(96)

C H, as(96)

C H2C1as(99)

C H2'1s(39).CI-bas(3X).CI-12as( 13)

C H2as(53).CH2<ls(25 ).CI-12as( 12)

C l-bas(35).C H2as(33 ).C I-I 2<ISC\ I )

C H2as( 49).CH 2as(2!)) .CI-l 2<lS(20)

C H2Clss(99)

C I-I ,ss(96)

C H 2SS( 49) _C H 2as(26 ).CH 2as(24)

C I-I 2ss(46).C I-I 2SS( 46 )

C I-I 2ss(93)

C H2SS(50).CH2SS(24 ).C1-1 2~~ ( 24)

C I-I , ao(361.C I-I , so( 15).CCs( 12)

C Hl ao(!)5)

C I-I , ao(55)

C H 20(35),CH20( 13),CI-i ,so( 10)

C I-12o(32),CI-I 2o( 17).CI-120( 14 )

C H2o(72).red.( 15)

C H20(39) ,CH20( 16).C I-120( 10)

C H20(24 ).C I-I 20( 17).CI-120( 12) CH 2()( IO j

C I-I 2W( 45 ).C I-I lSo(20 )

C I-I 2w(32).C H,so(20).C I-12C1w( 15)

C I-I 2w (27).CH2C1w( 22).C l-bw( I ])

C H2w(39).CI-h so( I 6 I.C I-I 2(J)( 16)

77

... Ieollld )

INDIAN J PURE & APPL PHYS, VOL 38, FEBRUARY 2000

Table 2 (Contd) ...

Observed frequency Calculated PED (cm- I ) frequency (%)" •

(cm- I )

IR RAMAN

1202 1195 CH2t(20),CH2W( 17),CH2t( 14)

1178 1173 1173 CH2t(44),CH2W( 15)

1155 CH2t(53),CH2t(21)

1134 CH2t(69),CH2t(24)

I 100 1101 C H2t(25),CCs( 12)

1093 CH2r( 14),CH)r( 14),CCs( 12).CCs( 12)

1076 1071 CH2Clt( 15),CCs( 14),CCs( 13),CCs( I 0)

1036 1031 CCs(27),CH2Clt( 14 ),CCs( 12)

994 990 995 CCs(38),CH2r( I 0)

970 965 966 CCs(24),CH2c.o( 12)

952 950 CCs(24),CH2Clt( 14 ),CCs( I I ),CCs( I 0)

890 883 CCs( 15).CH2r( 15),CCs( I I )

H68 862 870 CH3r(27),CCs( 16),CH2r( 15).CH2W( 12). CCs( 12)

7XO 789 CH2r(28),CH2r(26).CH2Clr( II)

752 751 CH)r(25).CCs(22),CH2r(20)

725 728 728 CH2r(32),CH2Clr( 16).CH2r( 15)

651" 651 647 CH2r(45) ,CH2Clr(38)

601 602 CCIs(59),CH)r(28) ,CH2r(24 ),CH2t( I 0) ....

596 CCIs(44),CH3r(35),CH2r(34).CH2t( 12)

455 454 453 CCC8(36). CCC8(26)

416 403 CCC8(33),CCCI8( 17).CCs( II)

290 306 CCC8(38).CCC8( 15).CCC8( I I )

235 CH)t(64 ),CCC8(20).CCCI8( I 0)

184 CCCI8(57),CH3t( 19),CCt( 15),red. (II)

145 CCC8(27),CCC8(26) ,CCC8(25). CCCI8( 17)

42 CCt(66),CCt(31)

39 CH2Clt(48),CCt(48)

19 CCt(50),CCt( 19),CH2Clt( 13).CCt( 13)

16 CCt(36).CH2Clt(33).CCt( 17).CCt( 13)

l - ch/oroiLex({l1l' VI Cil -2995 2995 2990 CH)as(96)

2995 2995 2994 CH)<ls(96)

2988 2992 CH2Clas(99) -...... ... (Contd)

JAGG I & JASIWAL: V IBRATIONAL ANALYSIS OF l -CHLOROHEXANE 7!)

T,lhlc :2 (Contd)

Ohscrvcd frcqucncy Calcu latcd PED - I frcquency (0;',)" (cm I

(cm· l)

IR RAMAN

2957 2949 CH2as(40),CH2as(38),C H2<1S( 13)

293X 2945 CH2<1S(53),CH2<1S(25),C H2aS( 12)

293X 2943 CH2<1S(35) ,CH2as(33),CH2<1s(3 l )

293X 2939 CH2<1S(49),CH2<1S(29).CH2as(20)

2912 29 12 CH2Ciss(99)

2Xn 2870 C H ~ss( 49).CH2SS(26) .CH 2SS( 24)

2X65 2X65 2863 CH2SS(49),CH2SS(26),C H2SS(24)

2X55 2858 CH2SS(5 1 ).CH2SS( 46)

2855 2855 CH2SS(92)

2855 2854 CH2SS( 50),CH2SS(24 ).CH2ss(24)

1462 1456 1467 CH, ao(36),CH,so( 15).CH2W( 15). CH2W( 12). CCs( 12)

1452 1455 CHlaO(95)

1444 1452 CHl aO(55)

14)() 1443 CH20(35).CH20( 13).CH,sb( 10)

1432 1436 1437 CH20(32).CH20( 16).C H20( 14)

1432 143() 1429 CH20(72) ,red.( 15)

14 13 CH20(39) ,CH20( 16) ,CH20( 1 0)

1372 1375 1370 CH20(24) ,CH20( 17).CH20( 12).CH20( 11 )

1346 1340 1337 CH2W( 45).CH~sO(20)

1310 1395 13 11 CH2W(32).CH2Clw( 15) .CH2W( 13)

12!)() 1294 CH2W(27).C H2Clw(22).C H2W( 13 )

1226 CH 2w(39),CH ~so( 16).C H2W( 16)

I I X5 II KO 11 92 CH2W(20). CH21( 18), CH21( 15)

117X 11 XO 11 76 CH2l(44).CH2W( 12)

11 56 CH2t(52) ,CH2t(23)

11 33 CH2t(64).CH2t(25)

I 100 11 04 CH2t(22),CCs( 11 )

1089 CCs(20),CCs( 16)

I05h 1062 CH2CiH 32).CCs( 16).Cl-121( 12)

I05() 1044 CCs(30).CCs( 13)

990 l)Kl) CCs(47).CH2Ciw( I (,).Cl-Ier( 12)

97() LJ65 %7 Cl-l}CII(2!)).CCs( 13 ).CHl ri 12)

LJ52 !)S I CCs(34).CCs( I S).CCs( I 0 ) ... (Conld)

XO INDI AN J PURE & APPL PHYS, VOL 38, FEBRUARY 2000

Tahle 2

Ohserved frequcncy (Clll- I )

---------------------------------IR

X6R

725

65 1

CliO

W I

455

RAMAN

X90

X62

R07

752

72X

651

454

Ca lculated frequency (cm-I )

887

862

797

746

72X

647

602

597

453

402

306

235

184

145

43

35

14

(Contd ) ..

PED (%)"

CI-i:1 r(26),CH2r( 13)

CCs(2 1 ),CH l r( 17) ,CH1W( 13)

CH2r(25).CH2C1r( 14),C H ~ r( 14)

CCs(33 ).CH1W(23),CH:\I-(2 1 )

CHl r(39).CHl r(2 1 ).CH1Cl r( 1(1)

C H2r( 45),CI-bClr(3X)

CCls(59),CH ~ r(2X) .CH l r(25),C H 1C l w( 15).Oht( I 0)

CCls(45) ,CH ~r(35).C I-h r(34).C H 2 t ( 12).CH1Clw( II )

CCCo(36),CCCo(27)

CCCo(33) .CCClo( 17).CCs( I I ),CCCo( I 0)

CCCo(38).CCCo( 15),CCCo( 12)

C Hyr(64),CCCo(20).CCClo( I 0)

CCClo(58).CCr( I X) CCs( 15).red ( 12).CCCi'il I I )

CCCo(27).CCCo(26 ).CCCo(25)

CCr(53 ),CH1Cll(25).CC1( I (,)

CC1( 4 7),Cl-bCll(23 ),CC1( 14)

CC1(55).CC1(20).CH1Cl l ( 13)

ObCll (35) ,CC1(26).CC1(2 1 ).CC1( 17)

"Contrihutions less than 10% arc omilled. Abhreviat ions used: as = anti sYlllmetri e stretch: ss=sYlllmetri c stretch: 0 = bend : ;10 = antisym­

meti c deformation: so = symmet ric deformat ion: w = wag: t = twist: r = rock: reel = redunda nt. Repeateclmodes are from di f ferent sy mme­

try coordinates

va lue or C-Ci stretch shows strong overl apping with CH1 and CH1Ci rock ing vibrati ons.

5 Acknowledgement The authors are grateful to Pro f. G A Crowder (De­

pa rtment of Chemi stry , Loui siana Tec h Uni versity, Loui siana, USA) fo r prov iding the in frared liquid phase spectra and also the Raman spectra of the com pound . He has also been courteous to prov ide us the latest version of Ihe computer program lI sed fo r ca lcul ati ons in the present work .

References I Schachl schneider J H & Snyder R G. S/Il'c /rochilll A c/{{ . I <.J

( 1<J(,3) 11 7.

2

4

5

7

Snyder R G & Sch;lchtschncider J H. S/I£'c/mc/lilll AI '/{{ . 1 1 ( 1965) 169.

.I aiswa l R M P & Crowder GA . lOll .I .\;/I('c/ms. 2X ( 1')X3)

160.

Crowder G A & Jaiswa l R M P . .I Mol .';/rue/ II ,.,' . 102 ( I <.JX3) 145.

Snyder R G & Schaehtschneider J H . .I Mo l Slll'c/ms. 30 ( I <JC1'» ) 290.

Jaiswa l R M p, Garg R K & Crowder G A. Pmc IlIdiwl A crlll

Sci (Ch£'1I1 Sci ). 102 ( I <)90) 66 1.

.I aiswa l R M P and Crowder G ;\ . .1 Mol Sf!CC/ro.l. t)t) ( 1')X3) <)3 .

Sch;lchtschneidcr J H Shel/ D I' I'I' loll/I /{'lI/ Co Tcch 1<1,/)(1/11

No.1. 23 1- 64 ( 1%4) ilnd 57-(,5 ( 1%5).

Crowder G A & Potter .l K . Call.l Sj l('c /m s. 3:l( 1lJ7<J ) (,4<.J .