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COMMUNICATIONS TO THE EDITOR
The blue compound contains titanium, aluminum, chlorine and organic groups; from the elementary quantitative analysis a ratio Ti :A1:C1 = 1: 1:2 has been found. The values 331 and 339 have been calculated for the molecular weight of the blue compound from two different cryoscopic measurements in benzene. By treating the blue product with 2-ethylhexanol, ethane is evolved; a quantitative gas volumetric determination shows that two moles of ethane are evolved per mole of compound. By treating the product with anhydrous hydrochloric acid in ether solution bis-(cyclopentadieny1)-titanium dichloride is formed in almost quantitative yield (more than 90%). The analytical data and the chemical behavior agree very well with a formula (CsH6)zTiClzA1(C&,)2, as shown in the table for (C~,Hs)zTiClzAl(C2H5)2
V d . 79
Although the complex is a catalyst for the ethylene polymerization, less active than the catalyst prepared from TiC14and ,41(CzHs)3,the composition of the complex strongly supports the hypothesis that the Ziegler type catalystss for the polymerizntion of ethylene are, generally, bimetallic complexes containing organometallic bonds. (8) K. Ziegler, Belgian Patent 533,362; K. Ziegler, E IIolakamp, H. Brei1 and H. Martin, A w e w . Chem., 67, 541 (1955).
ISTITUTO DI CHIMICA INDUSTRIALE DEL POLITECNICO DI MILANO MILANO, ITALY
GIULIONATTA PIEROPINO GIORGIO MAZLANTI UMBERTO GIAWIXI RECEIVED FEBRUARY 18, 1957
A NOVEL REARRANGEMENT I N THE 5-NITRONORBORNENE SERIES
Sir :
The failure of salts of 5nitronorbornenes (Ia, R = HI; Ib, R = CH32; IC, R = CaH53r4; shown in the aci form) to undergo the Nef reaction5 21.023 20. 7S4 c1, % 21.22 has been attributeds to homoallylic7 resonance 8.073 7.92 7. 90s -41, % 11) of the aci forms. We stabilization (I 14.33 14.34 14.55* Ti, % find, however, that, although a ketone is not ob16.07 17. 676 -C2HSr % 17.40 tained, I a does yield a nitrogen-containing transMol. weight 334 331 3398 formation product under Nef reaction conditions. It seems probable that, in the complex, both Addition of an ice-cold aqueous methanolic C6H6-groups are bound to the titanium atom and slurry of the sodium salt of I a to S.5% (by wt.) that both CzH6- groups are bound to the aluminum hydrochloric acid a t - 20 to - 10" gave in 30-3; atom. yields a rearrangement product (VI), m.p. 104.0By polymerizing ethylene in heptane solution in 106.5", isomeric with 5-nitronorbornene. A n d . the presence of 0.6 g. of the Ti-A1 complex a t 40 Calcd. for C7HsNO2(139.15): C, 60.42; H, 6.52; atm. and 95" after a reaction time of 20 hours, 8.4 N, 10.07. Found: C, 60.71; H , 6.63; N, 10.04; g. of white polymer has been obtained, which has mol. wt. (Rast) 150. YNH 3380, 3150; yc=o been fractionated by boiling solvent extraction 1667; YC=C-H 3040; yc=c 1616 (shoulder) cm.-' (acetone extractable fraction 10.1%; ether ex- in CHCl3. As is true with hydroxamic esters,X tractable fraction 1Byo, carbon tetrachloride ex- VI and VI1 do not give a color test with ferric tractable fraction 17.20%, residue 7o.9yO having chloride and are weakly acidic; they can be esintrinsic viscosity in tetralin a t 135" = 1.55 X 100 tracted with ether from lOyo sodium bicarbonate ml./g.). solution but not from 20% sodium hydroxide; As it is reported in the next table, (CsH6)2TiC12 they are regenerated upon acidification. alone is completely inactive for the ethylene polyHydrogenation of pure VI over platinic oxide merization ; A1(CzHJ3, accordingly with previously a t 2 atm. consumed 1.00 mole of hydrogen and published data,7 does not give solid polyethylene in gave in 96% yield a dihydro derivative (VII), m.p. the reaction conditions, but only low molecular 43-46', n Z 6 1.5065 ~ (on the supercooled liquid). weight oily polymers. Comparative experiments Anal. Calcd. for C7HllN02: C, 59.55; H , 7.85; were carried out a t 95' and 40 atm. N, 9.93. Found: C, 59.41; H, 7.79; N, 9-68. Y N H 3180; yc-0 1668 cm.-l. Dichromate oxidaCrysRe- talline tion of VI1 and VI11 gave glutaric acid. ac- polytion ethylOily Hydrogenation of VI over Raney nickel catalyst Soluble catalyst Solvent time, ene, polymers, a t 2 atm. (92y0 yield) or reduction of VI1 with iron Type Moles Type Cc. hours g. g. powder and aqueous ethanolic ammonium chlo(C6Hs)*TiClS 0.005 Benzene 100 20 0 0 ride solution9 yielded a tetrahydro derivative Al(CzHs)r .05 +Heptane 300 8 0 11.07" Calcd.
Found
(ChH&TiC12Al(C2Ha)z ,003 %-Heptane 40 8 7 0.4 0 66% of the product consists of hydrocarbons lower than decane. (3) Decomposition of the complex by HISO, 5%; titanium has been determined as titanium cupferrate, aluminum a s 8-oxyquinolinate, chlorine by gravimetric determination (I. Ubaldini and F. Capizzi, Chimica e Indnslria. 37, 779 (1955)). (4 Decomposition of the complex by Na20z; chlorine has been determined by the Volbard titration. ( 5 ) By gas volumetric determination. (6) By cryoscopic determination in benzene solution. (7) G. Natta, P. Pino, and M . Farina, Supplemenlo Ric. Scienf., 25, 120 (1955).
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(1) W. C. Wildman and C. H. Hemminger, J . Org. Chum., 17, 1 6 4 1 (1952). (2) E. E. Van Tamelen and R. J. Thiede, THISJ O L I R I V A I , , 74, 261: (1952). (3) W. E. Parham, W. T. Hunter and K. Hanson, ibid., 73, 50hX (1951). (4) U'. C. Wildman and R. B. Wildman, J. 01.. C'henh., 17, S i l l (1952). (5) W. E. Noland, C h e m . Revs., 55, 137 (1955). (6) W. C. Wildman and D. R. Saunders, J . Org. Chern.. 19, :i3i (1954). (7) *M. Simonetta and S. Winstein, Tms J O G R N A L , 76, 18 (1951). (8) H. L. Yale, Chem. Revs., 33, 231 (1943) (9) (a) V. 0. Lukashevich and M. A. Voroshilova, Comfit. r e n d . m a d . s c i . U.R.S.S., 2, 394 (1836); Orp. ( ' h e m I I ~ (U.S.S.R.), . 4, 253 (19371, C. A . , 32, 2091 (1938); Russian Patent 51.050. May 31, 1937;
June 5, 1957
COMMUNICATIONS TO THE EDITOR
(VIII) of VI, m.p. 95.5-96'. Anal. Calcd. for C~H13N02(143.18): C, 58.72; H, 9.15; N, 9.78. Found: C, 58.79; HI 8.98; N, 9.86; mol. wt. (Rast) 139; OH 3500; YNH 3390, 1589; yc-o 1668 in CHCla. VI11 evolved a gas on treatment with nitrous acid. When warmed with 20% sodium hydroxide solution VI11 evolved ammonia; under Schotten-Baumann conditions it yielded benzamide. Phenylurethan of VIII, m.p. 151.5153.5'. Anal. Calcd. for C14HI8N2O3:N, 10.68. Found: N, 10.67.
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placement, with inversion and ring closure, of the conjugate acid of the latter (possibly concerted as shown in V) would complete the cis-ring fusion of VI. (15) Taken in part from the M. S. thesis of Patricia A. McVeigh, University of Minnesota, 1954.
WAYLAND E. NOLAND SCHOOL OF CHEMISTRY JAMES H. COOLEY OF MINNESOTA UNIVERSITY A . TVICVEIGH~~ MINNEAPOLIS 14, MINNESOTA PATRICIA RECEIVED APRIL2, 1957 SOLVENT EFFECTS IN THE REACTIONS OF FREE RADICALS AND ATOMS'
Sir. Complexes between free radicals and aromatic hydrocarbons have been ~ u g g e s t e d , ~but - ~ conclusive evidence supporting their existence is lack111 I I1 ing. We have found that various aromatic sol/-tiso+ vents can drastically alter the position of attack of a chlorine atom on a branched-chain hydrocarbon and believe that this effect is connected with the ability of the aromatic hydrocarbon to form a complex with chlorine atoms. The data indicate that the complexed chlorine atom is much more selective than the free chlorine atom. This effect was observed in the photochlorina0 tion of 2,3-dimethylbutaneI analysis being perNH2 Fe+HIO I. NoOH %\/.'( formed by vapor phase chromatography. The 1I T 0 0 2. H + +OH NH4 -OxNH v I1 and 2-chloro-2,3-dimethylbutaneshave retention VI11 IX Warming VI11 with 1C-2070 sodium hydroxide times a t 80" of 33 and 22 minutes, respectively, in 2-m. B-column of a Perkin-Elmer model solution, followed by acidification, gave the a154B Vapor Fractometer. Since we have preknown1°-13 lactone IX, b.p. 69" (0.5 mm.), n 2 5 ~ viously demonstrated that the products of photo1.4727, m.p. -13.5' to -12". Anal. Calcd. for chlorination are a true measure of the point of atC7H1002 (126.15): C, 66.64; H, 7.99. Found: tack of the chlorine atom,6the relative reactivities C, 66.54; H, 7.67; mol. wt. (Rast) 144; yc=o of the tertiary and primary-hydrogen atoms were 1759, 3520 (overtone; sample was shown to be calculated by the equation pure by vapor phase chromatography). The inmoles tert.-chloride (12) frared spectrum of our sample was identical with Re. react. (tert./prim.) = moles prim.-chloride (2) an authentic sample of 1X,I1and there was no depression in mixed m.p. Alkaline permanganate TABLE I oxidation of our sample of IX gave glutaric acid; PHOTOCHLORINATION OF 2,3-DIMETHYLBUTANE AT 55' nitric acid oxidation of IX has been reported to Rel. react. ( l e r l . / p v i m . ) Solvent (4.0molar) give glutaric acid.IO 2,3-Dimethylbutane 3.7 The location of the double bond in VI has not Carbon tetrachloride 3.5 been determined through chemical evidence; it is Methyl acetate 4.3 assigned tentatively on the basis of the mechanism Nitromethane 3.4 (Ia I11 IV V -+ VI) proposed to account Trichloroethylene 3.4 for this novel fission of the norbomene ring sysPropionitrile 4.0 tem: Hydrolysis a t CZof protonated Ia (111, or a Nitrobenzene 4.7 more highly protonated version), with concerted Benzoyl chloride 6.4 shift of the double bond to C3-C4, fission of the Benzotrifluoride 6.9 C4-G bond, and elimination of hydroxyl to form 10 Chlorobenzene the nitrile oxide IV. Hydrolysis of the nitrile Benzene 14 oxide14 to the hydroxamic acid followed by disBenzene (25") 20
CY?
~
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C.A . , 33, 4601 (1939); (b) W. E. iioland, B. A. thesis, University of 15 o-Xylene Wisconsin, 1948; ( c ) S. M. McElvain, "The Characterization of OrMesitylene 17 ganic Compounds," rev. ed., The Macmillan Co., New York. S. Y., 24 t-Butylbenzene 1951,pp. 144-145. (10) J. v. Braun and W. Munch, Ann., 466,64 (1928). 1-Chloronaphthalene 37 (11) R. P. Linstead and E. M. Meade, J. Chem. SOC.,935 (1934). (1) Directive Effects in Aliphatic Substitutions. X. (12) W.Hiickel and W. Gelmroth, Ann., 514, 243 (1934). (13) W. E. Grigsby, J. Hind, J. Chanley and F. H. Westheimer, (2) G. A. Russell and H. C. Brown, THISJ O U R N A L , 77,4031 (1955). THISJOURNAL 64, 2606 (1942). (3) F.R. Mayo, ibid., 7 6 , 6133 (1963). (4) G. S.Hammond and C. E. Boozer, i b i d . , 76, 3861 (1954): G.S. (14) In support of the argument for nitrile oxide hydrolysis is the fact that hydrolysis of an ether solution of benzonitrile oxide goes with Hammond, C. E. Boozer, C. E. Hamilton and J. N. Sen, ibid., 77, 3238 concentrated hydrochloric acid a t room temperature to yield benzoic (1955). acid and hydroxylamine hydrochloride: H. Wieland, Bcr., 40, 1672 (5) M.T.Jacquiss and M. Szwarc, Nalrrrc, 170, 312 (1952). (1907). ( 6 ) H.C. Brown and G. A. Rursell, THIS JOURNAL, 74,3995 (1962),
