June20, 1961
COMMUNICATIONS TO THE EDITOR
2779
for sp3 hybridized C13 has values of about 4.0 rnents of the mass peak heights for Hz, H D and Dr C.P.S. The data presented here show that for spy in the completely decomposed sample. Assuming hybridized C13, JC1a-C-C-H is either equal or con- the hydrogen originated only from SbH3and SbD3, siderably greater than the corresponding Jc1a-c-H our preliminary results gave a ratio of 15 : 1 for the in the same compound. Such anomalies-spinhydride to the deuteride ratio. spin coupling constants do not decrease monoMost of the readily conceivable mechanisms for tonically with the number of bonds separating the the reactions producing stibine would be expected interacting nuclei-have been observed in various to yield SbH3, SbHnD, SbHDz and SbD3 in ratios metal alkyl^.^ The general impression has been which would be predicted statistically from the that JM-C-H is abnormally small. We wish to over-all H to D ratio in the stibine. For our suggest that perhaps, as in the case of C13,JM-C-C-H experiment, a statistical distribution would correis abnormally large, and more intensive studies on spond to the most abundant deuterated product J ' s between interacting nuclei separated by three being SbHZD. Hence, it was surprising to find bonds may explain decreases which are not mono- SbD3 as the only deuterated product. The D in tonic with the number of separating bonds. the stibine did not originate from borohydride since (5) (a) P. T. Narasimhan and M. T. Rogers, J. A m . Chem. Soc., the hydrogens of borohydride ion are known not to 82, 34 (1960); (b) R. E. Dessy. T. J. Flautt, H. H. JaffC and G. F. exchange4 with the hydrogen of an aqueous solvent. Reynolds, J . Chem. P h y s , 30, 1422 (1959); ( c ) E. B. Baker, ibid., One possibly is the existence of two independent 26, 960 (1957). paths, one resulting in SbH3 and the other SbDa. KEDZIECHEMICAL LABORATORY DEPARTMENT OF CHEMISTRY GERASIMOS J. KARABATSOSThe path leading to hydride formation would The second JOHN D. GRAHAM involve reactions only with BH,-. MICHIGAN STATEUNIVERSITY EASTLANSIXG, MICHIGAN FLOIEVANE path leading to the deuteride would involve reacRECEIVED APRIL21, 1961 tions of deuteriodiborane with Sb(II1). I n concentrated sulfuric acid some diborane5 is formed ANOMALOUS HYDROGEN-DEUTERIUM from borohydride ion; and diborane has exchangeDISTRIBUTION IN STIBINE PREPARED FROM able6 hydrogens. Such a two-path mechanism can ANTIMONY(II1) AND BOROHYDRIDE IN HEAVY be used to explain the appearance of SbDa (without WATER other deuterio species) in addition to the expected Sir: SbH3. We wish to report an unexpected deuteriumWork is in progress to elucidate the mechanism hydrogen distribution in the preparation of stibine. of this deuteration and to study the analogous This preparation yielded SbH3 to SbD3 in a ratio of with the corresponding ils, Sn and Ge about 15 : 1 with no partially deuterated stibine reactions compounds. detectable. The synthesis' consisted of slowly We wish to acknowledge assistance of Mr. N. dropping a heavy water solution containing 2.5F Neunke and thank Dr. H. Papazian for measuring NaOD, 0.5F KSbO(C4H406), and 0.4F KBHl into a the infrared spectrum. heavy water solution 2 F in D2S04 while vigorously (4) P. R. Girardot and R. W. Parry, J. A m . Chcm. Soc.. 7S, 2365 bubbling nitrogen through the reaction mixture a t (1951). 11 cm. total pressure. The total exchangeable (5) H.G.Weiss and I. Shapiro, ibid., 81, 6167 (1959). (6) S.Kaye and T. Freund, unpublished results. hydrogen was 97% deuterium. The gaseous stibine RESEARCH LABORATORY was trapped and purified as recommended by COWAIRSCIENTIFIC THOMAS FREUXD 5001 KEARNEY VILLAROAD Jolly. The infrared spectrum of our preparation showed SANDIEGO,CALIFORNIA RECEIVED APRIL22, 1961 peaks in the rock salt region a t 1945, 1882, 1825, 1406, 1362, 1320, 832 and 775 cm.-'. These eight THE LEAVING GROUP AS A FACTOR IN THE peaks, the only peaks in the spectrum of our sample, ALKYLATION OF AMBIDENT ANIONS are in agreement2 with the four fundamental vibra- Sir: tions of SbH3 and the two fundamental vibrations The reaction of nitroparaffin salts with alkyl of SbD3 which were in the range of the prism used. Although the intensity3 measurements could not be halides may occur as carbon-alkylation or as used to determine the relative amounts of SbH3 oxygen-alkylation. The latter is productive of to SbD3 it should be mentioned that the relative nitronic esters (11) which are not isolated; instead absorbancy of v1 for SbH3to SbD3 was about 10: 1. the carbonyl compound and oxime are obtained and R' Xass spectrometric analysis of the stibine showed a broad peak in the 120-130 region, no oxygen, a R--[-NO* tf R-C=N little water with HzO greatest and DzO least, and small amounts of Hz, H D and Dz with an H to D R"CH& R"CH2X ratio of about 15. The sample was decomposed in the gas phase by R' R' I I .oan electrical discharge, using a n ordinary Tesla R-C-NO~ R-C=h(iCH,R , coil leak detector external to the glass system. I The ratio of H to D was estimated from measureCH2-R" (1) W. L. Jolly, J. A m . Chcm. Soc., 88, 335 (1961); s.R. Gunn, I I1 W. L. Jolly and L. G. Green,J . Phys. Chcm., 84, 1334 (1960). it is generally assumed that they arise from the (2) W. H. Haynie and H. H. Nielsen, J . Chcm. Phys., 11, 1839 nitronic ester.I (1953); D. C. Smith, ibid., 19, 384 (1951); American Petroleum
[
'
+ 100
Nblet
>100
c1
>loo
OTos Br I
8 6 3
simply from nucleophilic displacement by the oxygen of the anion on the benzylic carbon; however, in the p-nitrobenzyl series, when X is a difficultly displaced group, a second mode of attack by the nitroparaffin anion has a chance to compete and it is this second process which is productive of carbon alkylation. The matter of mechanism is currently under investigation. Aside from its obvious significance as regards the alkylation of other ambident anions, the properties herein reported for the 9-nitrobenzyl system may very well be important in reactions involving non-anibident nucleophiles and this possibility is being explored. (3) Sponsored by the U. S. Army Research Office (Durham).
DEPARTMENT OF CHEMISTRY NATHAX KORNRLUM PAULPINK^ PURDUE UNIVERSITY LAFAYETTE, INDIANA KENNETHIJ. ’T-ORKA? RECEIVED APRIL 14, 1961
A MODEL FOR ANGLE STRAIN CALCULATIONS. OPTICALLY ACTIVE SYMMETRICALLY BRIDGED BIPHENYLS’**
Sir: The architecture of molecules of type I is uniquely suited for a comparison of theoretical and experimental evaluations of angle strain. A high degree
x
X
wQ+G / \
H2C CH,
BrCHz
CH2Br
C,H2 /CH2
CH300C COOCH:,
Y Ia,X=Y=O b,X=Y=S c,X=O,Y=S
11
HOCH, CHzOII IIIa, X = 0 b,X=S
of constitutional symmetry in cases where X = Y minimizes the assumptions ordinarily entailed in calculations for less symmetrical molecule^.^ We wish to report that calculated angle deformation energies in the transition state conformations for racemization of l a and Ib account for the experimentally observed energy barriers. (1) Acknowledgment is made t o t h e donors of T h e Petroleum Research Fund, administered by t h e American Chemical Society, for partial support of this research. We also thank t h e Alfred P.Sloan Foundation f o r partial support. (2) Satisfactory elemental analyses were obtained fur all substances reported. Chemical shifts a r e expressed for solulions in CDCIs, with reference t o external benzene. (3) E.g.,K. E. H o a l e t t , J . Chern. SOL.,1250 (1958); cf. F H. Westheimer, in M . S. Newman, “Steric Effects in Organic Chemistry.” Joliu IX’ile). and Sons, h’ew 170rk. N I,.,1956, Chapter 12.
