Resnik, Lee, and Powell (4) for the detection of organic acids. T h e salts of acids I and I1 each had a epot at about RI 44. Glycine gave no welldefined spot, but the ammonium salts of several other polyfunctional acids did respond to this method of detection, thui extending the usefulnoss of $quinolinol for spot detection. Acid I, as well ns 11, was essentially nonvolatile when neutralized fractions were stripped of solvent, acidified with phosphoric acid, and steam distilled. This constitutes further evidence against acid I being a member of the steamvolatile acids of cigarette smoke. Determination of Blanks, Blanks for the entire separations at pH 2.0 and S.7 were obtained by applying the full elution program to columns prepared exactly as those used in a n actuaI smoke acids analysis. Constant blanks (Table I), with the csccption of the small peak described above, mere obtained as long a s elution WRR carried out with a solvent of fixed composition. Thc blanks for the sepiimtion a t pIi 10 differed little from those obtained hy direct titration of the originnl solvent-namely, about 0.0002 meq. per 5 nil. of solvent mixture.
cti
manner reported for ‘the ammonium salts (3). Well-defined bpots with little streaking appeared after ninhydrin treatment. R, vaIues (Table 11) were reproducible within the usual limits,
Table 11.
RI Values of Sodium Salts of Volatile Acids“
Salt Anion R j X 100 Formate 21 Acetate 24 Propionate 32 n-Butyrate 45 n-Valerate (pentanoate) 59 Caproate 68 Heptylate (hcptanoate) 75 Caprylate (octanoate) 77 Conditions. Ascending on Whatmnn’R No. 1 paper in 1500 ml. of l-butanolwater-propylaminc (100 to 15 to 1 v./v.). Detection with ninhydrin in chloroform.
Titrated olucnts containing ncids from formic through caproic were applied directly t o paper without the indicator removal. The indicator
moved with Rt 82 to 85 and interfered only with the fastest moving acide (heptylic and above). Eluents containing only small amounts of acid were concentrated to obtain solutions applicable to paper. ACKNB WlEDOMENT
The cooperation of the research laboratories of the American Tobacco Co. and of the Liggett and Myers Tobacco Co. is gratefully acknowledged. LITERATURE CITED
Block, R. J., Durrum, E. L,,Zweig G., “Pa r Chromal$aihy aqd ElectroeCresis,l, cadenuc Press, hew York,f955. BuyRke, D. A,, Wilder, P.,Hobbs, M. E., AXAL.CHEM.29, 105 1967). Corcoran, G. B., Zbtd., 28, 160 tl956) Resnik, F. E., Lee, L. A,, Powell; W.A., [bid., 27, 928 (1955). De artment of 8hemietry Duke University Durham, N. C.
LOUISD. QUIN PELHAS WILDER,JR. Mmcus E, HOBES
RECEIVEDfor review May 31, 1957. Accepted January 9, 1958. Work RU ported in part by Damon Runyon moria1 Fund.
&g
e
SIR: Dccaborane reacts inatantaneously with a solution of iodine in methanol, evolving heat and hydrogen. This is in marked contrast to the nlcoholysis of decnhornnc, which is reported to be slow (I,,??) and to exhibit an induction period (1). When the decaborane ’u’as added to an excess of iodine in mcthnnol, and the excess backtitrnted with sodium thiosulfate solution, 40.2 f 0.1 equivalents of iodine werc consumcd per mole of decaborane. This is suggested a8 a quantitative method for decaborane. The equation abuld seem to be:
+
Paper Chromatography of Sodium Salts. The sodium salts (25 to 50 r ) were chromatographed in the
+
of iodine totalcd 44 (TabIe I). This suggests that hydrogen reacts with iodine in methanol solution, and this reaction w a ~shown to procced slowly. On this basis, thc reaction in a closcd system may be expressed by Equation 2, BiaHic
+ +-
+-
(20 n)Tt 30 CHaOH 10 B(0CHa)a (40 2n)HI (2 - n)Hr (2)
+ +
+
where n equals the number of moles of moleculnr hydrogen that huvc renctrd with iodine. The reaction of iodine with tetrn-
borane \vas investigated only in the closed system because of the difficultiw in handling tctraborane. The resiilts reported in Table I suggest the renction expressed by Equation 3, which is analogous to that of decaborane, with additional iodine reacting aitli the hydrogcn liherated.
+
+
B~HID 0 11 12 CHaOH -C 4 B(OCH8)s f 18 HI 2 H2 (3)
+
As the rate of rcaction of decaborane with a solution of iodine in methanol is estimntcd to be orders of magnitude
BioH14 20 It 30 CHaOH 4 10 B(OCH8)s 40 HI 2 H, (1)
+
+
In order to mensurc the qunntity of hydrogen evolvcd, tho rcnction waa carried out in a closed system, using a Toepler pump t o isolate the hydrogen. The amount of hydrogen cvolved in this proccdurc was less than that predicted by Equation 1 and the amount of iodine consumed waa . proportionally larger. The equivalcnts of hydrogen plus those
Table I,
Reaction of Iodine in Methanol with Boron Hydrides in a Closed System
Sample BiaHi4
,
Equiv. 12 pcr Mole 41.1 40.7 20.5 19,8 10.7
Equiv, Hg Evolved per Mole 2.8
3.3
1.2
1.7 1.8
Equiv. per XIole Calcd:
Total 43.9 44.0
21.7 21.5 21.5
44.0 22 .o
VOL. 30, NO. 4, APRIL 1958 e
847
larger than either the alcoholysis of decaborane with methanol alone or the reaction of iodine in methanol with hydrogen, it can be concluded that iodine in methanol solution reacts with boron-boron and boron-hydrogen bonds. The tact that part of the available hydrogen is evolvd in the molecular form suggests that two d8erent types of hydrogen are present. The two
moles of hydrogen evolved in an open system further suggest that these are derived from bridge hydrogen atoms present in the compound. It may thus be possibIe to differentiate chemically between bridge and nonbridge hydrogen in boron hydrides. ARTHURE. MESSNEal Callery Chemical CO., Callery, Pa.
I Present ad-, Eseo Reeearch and En ineering Co.,,P. 0. Box 61, Linden,
N.3.
LITERATURE CITED (1) BescheU, H. C., Meeker, T. R., J. Am. C b n , Soc. 78,1796 (1966). (2) Qutar G.'A., Schaeffer, 0. W., fbid., 78,3646 (1950).
~ P ~ C N V E for D review June 13, 1957. Accepted January 8, 195%
is(cyclope nta d isnyl)Zircon iurn Dichloride H. B, BRADLEY and L. G. DOWELL, Linde Co., Division of Union Carbide Corp., Tonawanda, N. Y.
Structural Formula of Bis(cyc1opentadieny1)Zirconium Dichloride Figure 1. Crystals of bis(cycl0pentadieny1)zirconium dichloride
IS(CSCLOPEST.\DIF:S\.L)~IRCOSIUII
DrcHLoRt1)s (1, 2) is sohb!e in benzcnc, chloroforni, iiiitl dimethyl Cellosolve. It is spsriiiply P O I U I J I ~ in pctrolcum cthcr. I t rfis+olvt.s and
Table I.
Principal lines in X-Ray Spectrum d
Ill0
slon'iy dcco~nposcs in nnter. Polymorphis~nhns not bccn observed.
0.67 5.90 5.67
1 .00 0.52
CIlliSTAL hIORPH0LOC~Y
5.60
4,64 4.61 3.94 3.88 3.76 3.72 3.46 3.33 3.28 3.18 2.996 2,843 2.797 2 749 2,725 2% 608 2.058 2.483 2.434 2 398 2.353 I
I
2.288
2.257 2.221
dl
0.57 0.78 0.05 0.40 0.07 0.05 0,08 0 09
0.Oi
0.03 0.02 0.07 0 .o:! 0.12 0.02 0.00 0.12 0.03 0.04 0.34
0.00 0.08 0.04 0.02 0.05 0.05
AWALWCAL CHEMISTRY
Crystnl systcin, Noiwclinic, Form and Ilnbit. Crystnllixcs from benzenr in rrctnngril:ir tablrta with truncated cdgcs, prcF(wcd oricn tntion (010) (see Figurc 1).
X-RAYDIFFRACTIOS DATA Ccll Dimcnsions. n = 6.20 A,; b = 6.58 A.; ,c,= 13,33A; @ = SDOD'. Formula I%cights prr cell. 2. Formula Wciglit. 202.24. Density. l.iS2 (pycnometer); 1.785 (x-ray). OPTICAL PROPERTIES
Rcfrnctive IndiceR. (Diryliglit filkr) rx 1.708 f 03lO5, fl = 1.712 d= 0,005, Y
= 1.76 I13 0.01.
Optic-$&-Angle. (Rcd filtrr) 3 2V = 21 , (Blue filtcr) = 21' = 43O, (Dtiylight filter) = 21' = 31". Dispcrsion, 1' > r, Optic Axinl Plunc, 10% '
Sign of Doublc Refraction. Positive
.A.critc Biscctrix. BXa parallel to b. Estinction. a A c = 13' (daylight
filtcr). JrolccuInr refraction. AIW X n% -I/ nb 2 X l / d = 80.6. Fusion Dntn. Melts nt 232' c. with subliinntion to givc euhedm! crystals (010) on cover law. The refractive indes of thc me% is 1.555 d= 0.008 a t the melting tempcmture.
+
ACKNOWLEDGMENT
The sample of bis(cycIopentndieny1) zirconium dichloride was prepared by J. C. Brantley and E. L. Morehouse of this laboratory. LIYERATURE CITED ( I ) Wilkinson, O., Birmingham, J, hl,, J . A n t . Chon. Sot. 76, 4281 (1054).
(2) Wilkinson, CI., Cotton, F. A,, Chem. and Ind. (London)XBM, 307,
COHTIUBUTIONS of crwh~logrsplriadata for thia section ahould be sent tp W. 6. McCrone, 500 East 33rd SL, Chitxigo 1% Ill.
