Molecular structure and conformation of gaseous chlorocarbonylsulfenyl chloride, ClSCOCl, as determined by electron diffraction

Journal Ekevier

ofMohculjrSfrucfure, Science Publishers

B-V.,

128 (1986) 4148 Ams+&rdam - Printed

in ‘l?ne Ketherlands

MOLECULAR S?‘RUCTURE AND CONFORMATION OF GASEOUS CHLOROCARRONYLS~7LFENYL CHLORIDE, CLSCOCI, AS DETERWiSED BY ELECTRON DIFFR4C’ITON

Deparfmenf

o;Ckemist~-,

KOLBJQRN

HAGEN

Depcrtment {Norway)

0: Ckemis@.

Colgate L’nicec;fy. Liniue.-siQ

Xnmilton,

of Troruiheim.

hTew York

ASW,

N-7000

13346

!rJ.S.A.)

T.-cndkeim

ABSTRACT Gaseous chIorocarbc~nybulfeny1 ch?oride, CLS-COCl, has been Investigated at 36” C by electron diffraction. The major conformer has the chlorine 2'~ms niiti to each other. A small amount (6.5 5 9.9%) of a second form may also be present. For the anti form the bond distances (r,) and valer.ce sngles (I,) are as follows: r(C=l3) = 1.183(s) -4, r(C-Cl) = 1_749(8j X.
The conf=brmations of several molecules wit-b the general fo,-mti RXCGCI (X=0, S) with R=CH3, C2H5 etc. [i-6) have been invea-tigated -using electron diffraction and microwave spectroscopy. The most stable conformer was found to be one where X-R is eclipsing the carboryl bond. However, suppo_rt I’o-r the presence of an additional form has also belen pub%hed for several of the znolecules, and some of this work has been re&wed by Jones and Owen

1’71For

molecules v&h R=CI, no information about structure or conforn tation has been published_ Since Cl?z3 and Cl are about the same size, but have quite different electronegativities, sta-uctural infomation about molecules wi’h R=CI would be of interest for comparison. In this publication we report the results of an investigation of chlorocarbonylsuhIeny1 chloride, ClS-COCl (Fig. I), using gas-phase eiectron difhction. E-XJ?ERI!vfENTAL

AND

DATA

REDUCTION

_A commercial sample of chlorocarbonylsulfenyl chloride with p*urity betkr than 95% was obtained from K 9; K. Election diHraciion.pho’agmphs wire recorded with Balzers Eldigra~h KDG-2 [S, 91 on Kod& Electron image plates with 2 nozzle tip tcmperaturc of 35°C. The electron wavelength was 402%2860/85/S03.30

Q 1985 Ekevier

Science

Pirhlishers

B.V.

C1 0 I

\

s -

//

c

\ Cl

Fig. 1. Diavn

of the an;i fern of chloroc=rbor.yk.uifenyl

calibrahd against tenzene Loebl- microdensitometer. and 6 plat.~, respectively, in the usual way [ll--131,

&--trick

[IO] _ Optid densities were measured by a Joyce nozz.!e-to-plate distances of SC) and 25 cm, 5 wtere selected for analysis. The data mere reduced and a cal-:uiated back,ground [i4] v:as slabtiacted from the data for each plate to yie!c esperimental molecular >ktensity distibution in the form. sI,(s). Sk-a f I n the long and short camera distances were obtained over the ranges 2.0@ < s =Z 15.00 and 4-00 < s < 29.75 A-‘, respectialy, at ir1te~u2& Qs = 025 A-‘. The average experimental intensity curves are shown in Fig. .%; the inditidual curves and backgrounds zrz availabk as sqplementary materials [l5] _ The s:.t-z~k scattertig and phase factors used were obtained from the tables of SchZfer et al. IX]. For

STRUCTZi’RE ANALYE%

An exF+menti radial distibution (RD) curve (Fig. 3) was calculated from the experimental ‘intensity curves of Fig_ 2. Theoreticai RD-curves were c&&&d for conformers with tie %vo chlorin? atoms anfi (G = O”), syn (Q = 180=) and gauche (Q = i20”) to each other, using reasonable vales for bond distances. and valence angles. These curves are shcwn in Fig. 3 together with the experimental RD-ru,-ve. From these curves it is ob-tious that the major ccnzormer is the one wit.1 the chlorine atoms cnti to each other. Refinements of the strucrxlre were carried out by the me?.hod of least sq-aes [17] based on intensity curves by adjusting 2 single theoretical curve to the two average curves (one each horn the long and short camera dis’r;ances) ~!sin,a a unit weight matrix. The dilferent conformers cf the molecliles cau be described by the following geometrical pareeetem: r(C=O), r(C+X), r(C-S), r(S-Cl), LSCO, LS:ZCl, LCSCI and Lo (the Cl+-S-Cl torsion angle; i-6 = 180 when the C-Cl. and S-Cl ‘bonds are e?lipsed).‘Vibrational amplitudes were caicukted using an assumed valence force field. Several of the vlbrational amplitudes could also be refined in the least-squares analysis. The values of r(C-Cl) and r(C-S) were found to be almost identical and It was therefore difficuit to determine whether r(C-Cl) was slightly longer th?il r(C+ ) or tice vem Bgfir,ements for oath OX & .; models were ctixd out. They ; II converged, and agreements between experimental and theoretical

48

I

5

0

.

15

:0

2:;

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--A

Fig. 2. Intensity curve% sZ,(s). Experimental curves (Ei, X2) the fno c-era di+aces. Theoretical curve (T) was cakulatid ete= in Table 1. Differences curves (D1, D2) are E--T.

.,p

30

are averages of all plates for from the StidCtuial pararn-

EXP. A

I

6

,,,,,,

..,A’.

.

I

.

_...._..l._..

2

Fig. 3. Esperimental radial gcucke and syr. confoxmerz 0.002 A=.

.

3

.

,

.

f

r.A

dktributioa curve orL chlorocarbonyl

5

compared qsith tieoreticai su!fenyl chioride. Dmping

cumes f w cnt!‘ coefficient B =

Fig. 1. P&dial diskibution c;irve5. The experimental c~lrve (top) is ca?cuh*rd from the composite of the ex.perimer..Lal curves of Fi& 2 after mrll-lir;lication 3y Z$&AC;~Q and with tie damping coe!Eicient B = 0.002 A'. Tn.ztheoretic4 curve rext comsponris to the model of Table 1. The vertical lines indicate the interatcnnic distances in the final model; the lenab of the Lirzs ze proportional to the weights of the distances. The difference curve is experimental minLs theoretical.

RD-curves were very good for both models. However, the model with r(C-S) > r(C-Clj gave a lower R-factor (7.1% vs 7.7%). The ,-ossiotiky of the presence of a second con iormer was also investigeted. , a model with tie two forms of tbe molecule ;;ssumed to hawe the szme Go-metq exceot for tic +orsionaI angle, 9, was tested. Refinement-a showed that ‘he secon?ri confo_wer had 2 torsional angle of 125 (a = 21)” uld 2 mole fraction -;lahueof 0.065 (u = 0.045). The fi.zl results from the least-squares refinements zre given in Table 1, uld theoretic4 intensity snd RD curves calculated from these results are shown in Figs. 2 and 4 tldgether wit.b difference ewes The correlation mat.rix is given in Table 2. DiSCUSSIC

N

Chloroczbo+

7lsuEenyl chloride was found to ha-/e the szme major con-zorres_3onding chlcqroesters and tllioesters. Substitutig 2 methyl group T:kh a cLAkne a.jom ?,herefore reeked id no ‘imporknt change in t.he conformation. A second form may also be present in ClSCOCl, but refinements of models witi only one conformer produced results only slightly poorer t;‘?zn a mtiel with 2 conformational mkture. We could therefore not positively prove the presence of a highenergy form, ‘olut up to 15%

fOEIN??

2s

the

45

Final parameter Pvameter r(C=O) tic+> J-(c--sj r(s--clj LS-C=3 L s<-CI L.C-S-Cl :_+, b LQ: = % anti

values for chlorocarbonykulfeny~ r&a 1.183(O) I.749(8) 1.791(9) 2.010(4) 126.9-/2.0) [email protected](2) 100.6(4) 0.0 125.2(42.0)

I O-034(7) 0.047 0.047 0.051(2)

chloride’. -Parameter

ra

1

tis-aj r(C.CI)

2.638<22) 2_6i5(24) 2_8?.i(7) 2.926(1’)

;-;g} .

r( O.-Cl)* r(Cl+z1), r(o--c!)G r(Cl--Cl)~

3.047124) 4.514(10) 3.S9.qlWj 3.136(422)

O-134( 22) 0.073(4) 0.113 0.175

(5)

93.Eq9.9)

aDistances (r-J and amplitudes (;j in -4, am&e-, in degrees. Parenthesized ur.certain:ies are 2a arid include estimates of systerr.atic errcm and correlation in expPrL.zestal data. Quantities in brackets were refines as a group. bC.SCCl tors%m angel in the lr;rr-enerEJ coEfonrer. cC13CCI torsion angle m a possible seccmd conformer_

of such a form could be present. Lf a second conformer is present, our refinements seemed to ir~diczte that it r;lay be a gauche form kx*ez~ of the syrr reported in the esters,khioesters. One of the problems in the structure refinements was to dekmine whether r(C-Clj was shorter than r(C-S). Results obtained for s-methylchlorotbioforma~ [2 ] , using microwave s_pectio:;copy, indicated that in this molecule r(C-Cl) > r(C-S). However, these results were obtained using only two sets of rotational corstants_ When the roktional constants for the two models of chlorocarbonylsulfenyl chloride (A: r(C-Cl) < r(C-Sj and 3: r(C-cI) > r(C-4)) w-ere calculated, they gave virtuaUy identical rotational constants. Use of only a few rotational cot_stznts alone E therefore probably not sufficient to distkguish these i;v?o mod&. For model B the following parameters were obtained: r(C-C!) = l-789(11), r(C-S) = 1.752(10) and LS-C=O = 129_6(1.8); the rest of the parameters were nearly identical-A+& those shown in Tabie 1. In Table 3 the gecmetqr of chlorocarbonylsulfenyl chloride is compared with results obtained for r&ted molecules. The C-Cl bonds h chloromethyl foAmate [l] and tichlo:rcmethyl sulfenyl chloride [21] are l-754(43 _A and 1.7X1) A. respectively. These x&-ties Ient support to modei A \r < r(C-S)). These two results and our present ED’ (C-Ci) mvastigation suggested that the C-C! and C-S bond values for s-methylchlorothioforma-te [2] might be in error and a reinvestigation might be -k order. Methyl chloroformate [I] and chlorocarbanyls-ulfeny! chloride have similar geometry except for the valence angle at the ester oxygen being significantly iaiier lhan khe corresponding arq!e at +&e sulfur atom. Simi2ar

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TABLE

3

n?oIecukr

stl-ucture

of cbiorocarbonykul,benyl

l-18315) l-744(8) 1.751(9)

?-(C=O) r(C-Ci)

r(C--S) r(S--CI)

Cl.1851 [l-789] ;1_75]

2.010(5) 126.9(2-O) 105.0(2>

LS(OjC=O LS(OjC-cl LC-S(O- jR

Bef. Method

ED

related

1.190(-3) 1_7+(4j

molecui&

-

l-75(1) 1 78(Z)

-

-

99_5(7j 2 ImT

are in Bngstrtims,

end some

-

l-22.0(1.6) 108.2(4)

100.6(4) Thiswork

nDistances

chloride

-

2_OS(l)

128-l(6) 108.7(4)

1 c2 51.’ 5)

114.4(1.7) 1

-9g:,:T‘,) 21

ED

ED

angles in degrees.

rk valence zmgles are also observed when other osyge? compounds are compared with the correspondir,g su?fur compounds [X3]. For example, the valence angle LCOCl is 112.8(2.1‘) in methyl :iypochlctile, CH30C1 [I93 while the angle LCSCl is 99.45(20)’ &I methyl sulfuql chloride, CH,SCl [20>. The Other Ydence fmgles and torsion an& in chlorocarbonyl salfeayl chloride are also in fair agreement with the results found for mefAylchlor* thioformate 127 _ differences

ACKNOWLEDGEZENTS

We are grateful to As. S. Gundersen and Mr. H. Volden for help -E&h reco_dkg the experimecti d&z. Part of this wo:rk was carried out &zing a visit of K. H. to Colgate Utiersity. REFERENCES I Q. Shen,

Acta

Ctem.

Scud.,

Ser. -4, 32 (1976j

245.

2K_ Camineti,R. K. Bohn 2nd N. S. True, J. Moi. Spectrosc.,

54 (1960) 356. 3X. S. True and R. K. Sohn, J. Am. Chsm. Sot., 9s (19?6) 1186. 4 K. S. True, C. J_ Silva and R. K. Bchn, J. Phys Che_nq 65 (1381) i132. 5 N. S. True and,R. K. Bohn, J. Xol. Struct., 36 (1977) 1.73. 6C. J. Silva, N. S. True 2nd R. K. Bohn, J. Moi. Struck, !il (1979) 163. 7 G. L L. Jones and N. L_ Owen, J. 3%~:. Struck., 18 (1973) 1. 8 W. Zeti, J. Harw and L. Wegmann, 2. Instrumentenkd.~ 74 (1966) 84. 9 0. Bzstiensec, G. Graber and L. X’egmann, Balkers Higli Vacuum REP_- 25 (1953) 1. 10K. Tamagzwz, T. Ii]Imz End M. Kimurn, J. Mu1 Struct., 30 (19’76) 243. 1iK. Hager? and K. Hedberg, J. Am. Chem. Sot., 95 (i973) 1303. 12G. Gundersen and K. Hedberg, J. Chem. Phys., 51(1969) 2500. 133. _Anderses. H M. Seip, T. G. Sirr+rd and R. Std;evik, -4cta Chem. Scand., 28 (1969) 3224.

14 L. X&berg, AbsIx. Filth Austin Symp. 1974, p_ 37_ 15_4vaileb!e from Bi_,LD ss SupplementE

on Gas Phase Publication

Mel. No.

Struti., S?..

Austin, 90106.

‘II?& Merck (See

J. Mol.

34 (7-976) 322 ?Or further details Gf BLLD.1 18 L. SciGfer, -2. C. Yates and R. k Bc&am, J. Chem. P~Js., 55 (19'71) 3055. 17 K. Hed’xg and M. I;vaski, Acta Crystallogr., 17 (1964) 529. i8J. Ii. C4lsnoc, E. Hirotz, K. Ku&i&u, W. J. LzIferty, -4 G. M&i md C. S. Pate, Structure da’s oi Free Polyatomic Nlo!ecules, hndolt-B&ns%in, New Series, Vol_ 7, Sp%ger-Verlq, Be&n, 1976. 19J. S. Rigden azld S. S. B~tiher, J. Chen. ?hy;., SO (1964) 2109. 20X. Guznieri. L. Chxpex;tier 2nd B. Xii&. Z- Natirfosch., Teil A 28 (1573) 1721. 21 N. K Aleksew zznd F. K. Velichko, J. Struct. Chern. (USSR), (English Trars.), 8 (1967) 6. SZCYCC~.,