along the entire CI~ anionoid fragment and, due to this, an increase in the order of the CN bond (PCN) and a

decrease in the order of the NO bond (PNO), although the ratio PNO > PCN, which is characteristic for non- ionized nitro compounds, should be retained here.

To ascertain the characteristics of the electronic structure of the CNY molecule we made a quantum- + chemical calculation by the SC F MO LCAO method as the C NDO/2 approximation of the molecules of (CH3)2S- CNO 2 (CN)(I), CH3NO2, CH2(NO2)CN, and their anions (Table 3). For (1) the geometric parameterswere aver- aged from the x-ray structure analysis data for the molecules of (CH3)2S-C(CN) 2 [8] and (CGHs)2S-C(NO2) 2 [9]: CNbond =1.4, NO=1.24A, (ONO=124 ~ .

The calculated dipole moment of the (1) molecule is high (10.32 D), which is in agreement with the data for the dipole moments of sulfonium C-ylides [5]. In the NO 2 group the order of the CN bond is greater than

one, but PCN < PNO, which is in agreement with the assumption, * made on the basis of studying the vibrational spectra (see Table 3), that in its electronic parameters the NO 2 group in CNY is closer to the NO 2 group of co- valent nitro compounds, and not their salts.

CONCLUSIONS

Based on the data of the vibrational spectra and quantum-chemical calculation, in its electronic struc- ture the nitro group in sulfonium C-nitro ylides is closer to the nitro groups in nonionized nitro compounds than in their salts.

LITERATURE CITED

i. K.I. Rezchikov, O. P. Shitov, A. P. Seleznev, and V. A. Tartakovskii, Izv. Akad. Nauk SSSR, Set. Khim., 1129 (1979).

2. G.F. Whifield and M. 8. Beilan, Tetrahedron Lett., 3545 (1970). 3. A. McKillop, E. A. Sedor, B. M. Culbertson, and S. Wawzonek, Chem. Rev., 7__3 , No. 2, 278 (1973). 4. K. Wallenfells, K. Friedrich, J. Rieser, W. Ertel, and H. Thieme, Angew. Chem., 8_88, 311 (1976). 5. B. Trost and L. Melvin, Chemistry of Sulfur Ylides, Academic Press, New York (1975).

6. S.S. Novikov, G. A. Shvekhgeimer, V. V. Sevost'yanova, and V. A. Shlyapochnikov, Chemistry of Aliphatic and Alicyclic Nitro Compounds [in Russian], Khimiya, Moscow (1974).

7. J.R. Murdoch, A. Streitweiser, and S. Gabriel, J. Am. Chem. Soe., i00, 6338 (1978). 8. A.T. Christensen and W. G. Witmore, Acta Cryst., B25, 73 (1969). 9. V.V. Semenov, L. O. Atovmyan, N. I. Golovina, G. A. Mukhina, K. Ya. Burshtein, and S. A. She-

velev, Izv. Akad. Nauk SSSR, Ser. Khim., 801 (1981).

�9 This assumption is confirmed by a prior calculation of the frequencies and form of the normal vibrations of n i t ro y l ide m o l e c u l e s .

SPECTRA AND STRUCTURE OF SULFONIUM

C-DINITRO YLIDES

K. I. Rezchikova, 0. P. Shitov, UDC 543.422:541.6:541.49:547.414..547.279.53 V. A. Tartakovskii, and V. A. Shlyapochnikov

As a continuation of studying the structure of sulfonium C-nitro ylides employing spectroscopLc methods [i] we studied the vibrational spectra of C-dinitro ylides (DNY} of type

Rl ~+ _

8--C(N02)2 1~ 1 = R z = CHs, C2H~, CaH~, C~H~, CsH s . /

R= The e x p e r i m e n t was run the s a m e as in [1]. Our ob jec t ive was to i n t e r p r e t a n u m b e r of the p r i n e i p a l

v i b r a t i o n f r e q u e n c i e s of DNY m o l e c u l e s , emp loy ing i so topic s u b s t i t u t i o n , a c o m p a r i s o n of the IR and R a m a n s p e c t r a (with m e a s u r e m e n t of the d e g r e e of d e p o l a r i z a t i o n of the l i ne s ) , and a l so the e x p e r i m e n t a l da ta on the s p e c t r a of the C - m o n o n i t r o y l ides [1] and the l i t e r a t u r e da ta [2, 3].

N. D. Zelinskii Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow. Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1407-1409, June, 1981. Original ar- ticle submitted August 4, 1980.

0 5 6 8 - 5 2 3 0 / 8 1 / 3 0 0 6 - 1129 $07.50 �9 1982 P l e n u m Pub l i sh ing C o r p o r a t i o n 1129

TABLE i. Frequencies of Stretching Vibrations of NO 2 Group in

Vibrational Spectra of Sulfonium C-Dinitro Ylides (Solids, u, cm -i)

VasNO-' in spec t r a ~sNO~ in spec t r a vGN in s p e c t r a

C o m p o u n d ) IR R a m a n IR { R a m a n IR R a m a n

!

( c u , ) ~ (N02)~ w 8~ v. s

4 - - -

(CD3) ~S-G ( N Q ) 2

+ - -

(C2H5) 2 8 - C (NO2).,

+ --

(C3H0 2S-C (NO~) 2

4 - _ _

(C~Hg) 2 8 - C (N02)

4 - - -

(CsH~) 2 8 - C ( N 0 2 ) 2

t490 s. br 1460 sh

t485 s 1460 sh

t486 s

t497s

t494 s

1502 s

1492 v. w 1476 v. w

1492 v. w 1476 v. w

1498 w t486 w

1494 w t480 w

t490 v .w

1492 w t472 w

t348 w t275 s. br t265 s. b r 1245s, br

t330w 1285s. br t275s, br 12552. br

t33,0 w t272 s t258 s t 23 t s

t327 w t260 w t 24 t w t229 s t 2 t 0 s

t322 v. w i246 s t226 s t200 w

t 3 3 0 m t275 s t252 w r

%w

830 v. w

835 w

828 s

838 V.s

832 v . s

822 v . s

828 s

TABLE 2. Ranges in the Frequencies of the Stretching Vibrations

of the NO 2 Group of Dinitro Ylides, Dinitro Compounds, and Their Salts (u, cm -I)

C o m p o u n d VasNO2 'vsNOz vCN

R~R~C (NO2) 2 '[4] RHC(NO2h [41

/ R~

RC(N02) 2 [41

~ t 6 0 0

t 5 0 0 - t 4 6 0

1 3 0 0 - t 2 0 0 t 2 0 0 - t t 2 0

1 4 0 0 - t 3 8 0 t 3 4 0 - t 3 3 0

1 3 5 0 - t 2 0 0

t 2 0 0 - t 0 4 0 t 0 0 5 - 8 1 8

900 -800

8 4 0 - 8 t 5

1500-1440 t 3 7 0 - t 3 2 0

Analogous to the mononitro ylides, in the spectra of the DNY the vibration frequencies of the NO 2 group

are changed substantially when compared with the spectra of various nitro compounds and their salts. The

assignment of the latter is shown in Table I.

In Table 2 is compared the ranges in the frequencies of the stretching vibrations of the NO 2 group in the

DNY with the corresponding ranges for the dinitro compounds and their salts.

As can be seen, according to the proposed interpretation (see Table i), the arrangement order of the

Uas NO 2 and u s NO 2 frequencies in the spectra of the DNY is the same as for the dinitro compounds, but is in

the reverse order to these frequencies in the salts of the gem-dinitroalkanes [4], although definite differences

exist between the u NO 2 frequencies of the nonionized dinitro compounds and the DNY. Thus, the Uas bands of

the vibrations of the NO 2 group are shifted toward lower frequencies when compared with the dinitro compounds

[4] (see Tables 1 and 2), while the u s are not shifted as much.

Since the arrangement order of the Uas NO 2 and v s NO 2 frequencies is a quite rigorous criterion of the iomc or covalent structure for various classes of nitro compounds [4], then on the basis of interpreting the

frequencies of the stretching vibrations of the NO 2 group it may be assumed that in the DNY, analogous to the

C-mononitro ylides, the electronic structure of the NO 2 group is closer to that of the NO 2 group in dinitro

compounds, and not their salts. However, the effects of a partial delocalization of the negative charge of the

C atom and an increase in the order of the CN bond in the DNY are apparently substantially weaker than in the

mononitro ylides.

1 1 3 0

TABLE 3. Charges on Atoms, Groups, and Bond Orders of Mole- cules of (CH3)2~-C(NO2)2, Dinitromethane, and Its Anion*

Compound

CH2 (NO2) z

+ -

(CHa) ~S'-C(NO~)a

CI~(NQ) 2

0,337

Charges on atoms

Cylide N

0,009 0,497

--0,t99 0,5t5

--0,055 0,349

o f

-0,291

-0,414

-0,442

C o mpound

CH2(N02)2 + --

(CH3)2S--C(NO~)a

CH(N02)2

l harges on atoms

N O . ,

-0,085

-0,237

-0,477

C (NO~)

-0,I60

-0,673

-l,Oi

Bond order

S-Cylide

0,866

Cylide'-N

0,963

t,i37

1,384

N - - O

1,45i

1,3i5

'1,072

* The obtained calculation results are in agreement with the liter-

ature data [5].

Maximum charge on outer O atom of NO 2 group.

For a detailed elucidation of the charac te r i s t i c s of the electronic s t ruc ture of the DNY we used the SCF MO LCAO method as the CNDO/2 approximation to make a quantum-chemical calculation of the molecules of

+ - -

(CH3)2S-C(NO2) 2 (I), dini tromethane (DNM), and its anion (Table 3).

For (I) the geometr ic pa ramete r s corresponded to the averaged data of the x - r a y s t ruc ture analys is of + - -

the (CH3)2~-C(CN)2 [6] and (C6Hs)2S-C(NO2} 2 [2] molecules: CN bond 1.4, NO 1.22 /k, (ONO = 122 ~ and the SC(NO2) 2 f ragment was taken as being planar. The geometr ic pa ramete r s of DNM were averaged f rom the data on the s t ruc ture of CH3NO2, CH(NO2)3, and C(NO2) 4 [7]: CN bond 1.495, NO 1.220 A, < ONO = 127 ~ The geo- met ry of the DNM anion corresponded to the x - r a y s t ruc ture analysis data for its K salt [8], with the condition that the NO 2 groups are equivalent.

According to the calculat ions, the dipole moment value for (I) (1043 D) is in good agreement with the ex- per imental value [2], which permits assuming that the obtained distr ibution of the charges in the (I) molecule t ruly ref lects the picture of the e lec t ron cloud.

In the DNM, its anion, and (I) se r ies the grea tes t changes in the charge occur on the C atom. In the ylide molecule it is substantial ly higher than the corresponding change in the DNM molecule (in absolute value). This is apparently due to the existence of a g rea te r positive charge on the S atom, which prevents complete delocalization of the negative charge of the C atom along the entire dinitro methylide fragment. The values of the charges on the O atoms in the NO 2 group of (I) are c lose r to the analogous values in the DNM anion. The rat io of the orders of the CN and NO bonds in the NO 2 group of the (I) molecule (1.137/1.315) is c lose r to the analogous values in DNM (0.963/1.450) than in its anion (1.384/1.072) (see Table 3).

As a resul t , in their e lectronic s t ruc ture the NO 2 groups in the DNY molecules apparently occupy a spe- cial intermediate place in the ser ies of nonionized nitro compounds and their sal ts , differing in their ionicity f rom the NO2 groups of the f i rs t and second.

CONCLUSIONS

Based on the data of the vibrational spectra of__sulfonium C-dinitro ylides and the quantum-chemical cal- culation of the electronic structure of the (CH3)2S-C(NO2) 2 molecule the nitro groups of dinitro ylides in their electronic structure differ substantially from the nitro groups of both the gem-dinitroalkanes and their salts~

1.

2.

LITERATUIRE CITED

K. I. iRezchikova, O. P. Shitov, V. A. Tartakovskii, and V. A. Shlyapochnikov, Izv. Akad. Nauk SSSR, Ser. Khim., 1403 (1981).

V. V. Semenov, L. O. Avtovmyan, N. I. Golovina, G. A. Mukhina, K. Ya. Burshtein, and S. A. She- velev, Izv. Akad. Nauk SSSR, Set. Khim., 801 (1981).

1131

3,

4.

5.

6. 7.

8.

O. P. Shitov, V. N. Koridrat 'ev, A. P. Seleznev, and V. A. Tartakovskii , Izv. Akad. Nauk SSSR, Ser. Khim. , 240 (1977). S. S. Novikov, G. A. Shvekhgeimer, V. V. Sevost 'yanova, and V. A. Shlyapochnikov, Chemis t ry of Aliphatic and Alicyclic Nitro Compounds [in Russian], Khimiya, Moscow (1974). A. B. Belik, R. Z. Zakharyan, and V. A. Shlyapochnikov, Izv. Akad. Nauk SSSR, Set. Khim. , 1714 (1976). A. T. Chris tensen and W. G. Witmore, Acta C r y s t . , B25, 73 (1969). L. V. Vilkov, V. S. Mastryukov, and N. I. Sadova, Determinat ion of Geometr ic Structure of Free Molecules [in Russian], Khimiya, Leningrad (1978). N. V. Gr igor ' eva , N. V. Margol is , I. N. Shokhor, I. V. Tselinskii , and V. V. Mel'nikov, Zh. ' Strukt. Khim. , 9, No, 3, 547 (1968).

CODIMERIZATION OF C 6 -Clo c~-OLEFINS WITH

BUTADIENE USING ZIRCONIUM COMPLEXES

O. S. V o s t r i k o v a , A. G. I b r a g i m o v , G. A. T o l s t i k o v , L . M. Z e l e n o v a , a n d U. M. D z h e m i l e v

UDC 542.97:547.313.6:547.315.2

Zirconium complexes, which are widely used in organic synthesis [1, 2], are also efficient and highly select ive catalysts for the homodimerizat ion of dienes and olefins [3-5] and the codimerizat ion of butadiene with ethylene [6]. The use of z i rconium complexes for the codimerizat ion of 1 ,3-d ienes with the higher ~ - olefins is not reported in the l i te ra ture .

We studied the react ion of butadiene with 1-hexene, 1-octene, 1-nonene, and 1-decene in the presence of the following z i rconium complexes: ZrC14-A1Et2C1, Zr(OC4Hgh- A1Et2C1 [4], Zr(OQHg) 4 - P P h 3-A1Et2CI [5], and (CPD)2*-ZrC12-EtMgBr [6]. Of them, only the f i rs t proved to be active in the indicated reaction. Thus, the codimerizat ion of equimolar amounts of butadiene and 1-hexene on this catalyst gave a mixture of homodimers and codimers in an overall yield of ~80%. The 1-hexene homodimers in this mixture were r e - presented by the i somer ic 5-methylundecenes [4] and the butadiene d imers , 4-vinylcyclohexene and n -oc ta - t r ienes . The amount of codimers in the catalyzate does not exceed 20%. They represen t a mixture of 5 -me- thylene-2-nonene (Ia) and t r ans -5 -me thy l -2 -nonene (IIa) in a 6:4 ratio. The codimers were separated by p re - parative GLC, and their s t ruc ture was confirmed by spect ra l methods. Judging by its s t ruc ture , diene (I) is formed by the 1 ,4-addi t ion of 1-hexene to butadiene, while t rans -a lkene (II) is probably the react ion product of diene (I) with A1Et2C1, which is a component of the cata lyst [7].

It should be mentioned that the codimerizat ion of butadiene with 1-hexene proceeds only above 120~ whereas the homodimerizat ion of the higher a -o le f ins on the given catalyst proceeds even at 20 ~ and that of the 1 ,3-d ienes at 80-100 ~ The addition of e lec t ron-donor ligand act ivators (PPh 3, pyridine, THF) to the ca- ta lys t suppresses the homodimeriza t !on of 1-hexene, but does not affect the yield and composition of the buta- diene codimers and d imers . The homodimer iza t ion of 1-hexene is also suppressed at 20-60 ~ by butadiene.

The obtained data make it possible to postulate that triphenylphosphine, pyridine, and butadiene are "s t ronger" e lec t ron-donor ligands than 1-hexene, and that they form more stable coordinat ion-saturated com- plexes with the central atom of the cata lyst than do alkenes.

,,

(Ia--d) (IIa- d ) (IIIa- d) (IV a- d)

CPD = cyclopentadiene.

Institute of Chemis t ry , Bashkir Branch of the Academy of Sciences of the USSR, Ufa. Izves t iya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1410-1412, June, 1981. submitted October 3, 1980.

Translated f rom Original ar t ic le

1132 0568-5230/81/3006-1132507.50 �9 1982 Plenum Publishing Corporat ion