2650
Vol. 77
NOTES
the wave lengths of the absorption bands. The 1.2 I spectrum of the praseodymium system, as given in Fig. 1, is typical. Wave bength values found were: La+3,5200,5600, 6065 A.; Pr+3,5220,5600, 6050 A.; Ndf3, 5225, 5600, 6045 A.; Sm:3, 5220, 5600, 6040 pi.; Gd+3, 5225, 5600, GO25 A.; Fa, 5225, 5600, 6020 A.; Er+3, 5210, 5580, 6010 A. All spectra amount to modifications of the naph0 1 2 3 4 5 6 7 8 9Metal thazarin spectrum produced by the presence of the 9 8 7 6 5 4 3 2 1 Reagent rare earth metal ions.3 In all cases, concentrations Comp of soh. in ml of these ions were too low to permit detections of Fig. 2 - Continuous variations plot for praseodymiumany of the characteristic rare earth light absorptiaphthazarin system; measurements, ca. 25 '; Cary retion~.~ 1
E
cording spectrophotometer with slit control a t 10, chart range at 0-2.5, Hi-Lo knob a t Lo gears a t 60 driving 60 driven, scanning a t 5 A. per sec.; IO0 cm. demountable cells with quartz windows.
PI -1.2
I--
3
I
with t h ~ r i u msuch , ~ species show cationic characteristics but have many of the properties of polymeric . aggregates. Adherence to Beer's Law.-As shown bv the data in Table I, rather close adherence to Beer's law is obtained in praseodymium or erbium ion concentrations up to ca. 40 X mole/liter. The marked similarities noted among the spectra of these systems irrespective of rare earth metal ion suggest adherence to Beer's law for the entire series.
I
TABLEI BEER'SLAWADHERENCE OF XAPHTHAZARIN-RARE EARTH METALIONSYSTEMS Metal ion concn mold
0 O 2' i /
x
4000
4500
5000
5500
6000
6500
7000
A,ANGSTROMS. Fig. 1.- Absorption spectrum of praseodymium-naphthazarin complex in ethanol; concentration, 10.5 X mole praseodymium per liter; measurements ca. 25"; Cary recording spectrophotometer with slit control a t 10, chart range at 0-2.5, Hi-L? Knob a t Lo, gears at 60 driving, 60 driven, scanning a t 5 A . per sec.; 1.00 cm. demountable cells with quartz windows.
1rP
7 14 21 28 33 42 49 56
Praseodymium, 6050
km
ea
x
A.
lo-*
Erbium. 6010 A.
k
*x
10-8
11.00 9.71 65.75 10.43 10.13 62.35 11.33 9.86 67.90 11.72 70.15 9.93 11.86 713.90 9.54 11.43 68.40 9.29 10.98 9.35 65.65 i n . 54 8.75 63.03 __ 11.16 66.77 Av. 67.58 9.57 Specific extinction, k, is given by the relationship k = (logdo/l)/cl, 1 being in cm. and c being expressed in g. metal ion/l. When c is in mole/liter, k becomes e, the molecular extinction. 68.96 72.00 69.97 70.48 67.74 65.92 63.45 62.11
Compositions of the Colored Species.-Inasmuch as the absorption spectra of naphthazarinConclusions.-Although the naphthazarin reacpraseodymium and naphthazarin-erbium solutions (taken as typical) showed no material variation, tion shows no specificity for individual rare earth except in absorption intensities, for naphthazarin metal ions, it is a sensitive color reaction for any to rare earth metal ion mole ratios of 3: 1, 2: 1, 1 : 1, member of the series. 1 :2 and 1:3, the presence of but a single absorbing Acknowledgment.-Support received from an species was indicated in each instance. An applica- E. I. du Pont de Nemours and Co. Grant-in-aid is tion of a modification6 of Job's method of continu- gratefully acknowledged. ous variations' to both praseodymium and erbium NOYESCHEMICAL LABORATORY systems showed the colored species to contain UNIVERSITY OF ILLINOIS naphthazarin and rare earth metal ions in 2 :1 mole URBANA,ILLINOIS ratios. This is shown for praseodymium in Fig. 2. Although this stoichiometry is the same as that Burning Velocities of Isopropenyl and Diisopropenyl of the thorium c ~ m p l e x ,continuous ~ variations Acetylene data suggest the rare earth metal complexes to be BY PAULWAGNER somewhat less stable than the thorium species. As ( 5 ) T. Moeller and J. C . Arantley, Anal. Chem., 83, 433 (1950). (6) W. C . Vosburgh and G. R. Cooper, THISJ O U R N A L , 63, 437
(1941). (7) P. Job, A n n . rhiwz., [lo] 9, 113 (1928).
3, l W l RECEIVED DECEMBER
The relationship between molecular structure and combustion behavior has been under investiga-
May 5, 1935
NOTES
265 1
tion a t the N.A.C.A. Lewis laboratory. One phase changes are altered, in some cases greatly, when the of this general program has been concerned with anionic composition of the solution is changed. the influence of molecular structure on the burning .Corresponding effects are also found frequently in velocities of hydrocarbon-air mixtures. The pres- non-equilibrium oxidation-reduction. I n the case of exchange between thallium(1) and ent work on the acetylene derivatives should thallium(II1) in aqueous solution it is known that allow further insight into these phenomena. Burning velocities were measured in an open the rate is affected by nitrate4 and is very sensitive burner type apparatus' a t a pressure of 1 atmos- to chloride.s*6 The purpose of the present work phere. Burning velocity of isopropenyl acetylene was to study the effect of cyanide on this reaction was measured a t an initial mixture temperature of in perchlorate-cyanide mixtures. 298°K. The high boiling point of diisopropenyl aceExperimental tylene required that the burning-velocity determiThe exchange reaction was followed by means of nations be made a t elevated initial mixture temperaradioactive thallium, T1204, obtained from Oak tures. Consequent calculation of temperature deRidge. The irradiated thallous nitrate was dispendence of the burning velocity (UTOT~.~') per- solved in distilled water, and thallous perchlorate mitted extrapolation' of the measured quantity to was precipitated with perchloric acid. The salt T i = 298°K. This value is given in parentheses was purified by several successive recrystallizain Table I. Experimental values of maximum tions from distilled water. The final product was burning velocity and the concentrations a t which dissolved in distilled water t o give a stock solution these maxima occur are listed in Table I. The burn- of radioactive thallous perchlorate. The specific ing velocities of both compounds are consistent activity was determined to be 2.3 microcuries per with previously discussed' structure relationships. milligram of thallium. A test for nitrate, with brucine, was negative. TABLEI % StoichioA stock solution of inactive thallous perchlorate Ti ur(max.1 metric at was prepared in the fashion just described, starting Compound (OK.) (cm./sec.) maximum with reagent grade thallous perchlorate. Isopropenyl acetylene 298 62.0 105 The thallic perchlorate stock solution was preDiisopropenyl acetylene 425 88.0 105 pared ele~trolytically~~-~6 from a solution of puriDiisopropenyl acetylene 377 74.0 105 fied thallous perchlorate in perchloric acid. The (298) (52.3) 105 Diisopropenyl acetylene final acidity was 2.86 f. A test for chloride with (1) P.Wagner and G. L. Dugger, THISJOURNAL, 77, 227 (1955). silver nitrate (0.5fin the mixture) was negative. NACA LEWISFLIGHT PROPULSION LABORATORY The other reagents used were C.P. or reagent CLEVELAND, OHIO grade. Reaction mixtures were prepared by mixing in a The Effect of Cyanide on the Rate of the Thallous- volumetric flask the appropriate amounts of stock solutions containing TICIO,, Tl(C10J3, HC104, Thallic Exchange NaC104 and NaCN. The reaction mixtures were BY EDUARDO PENNA-FRANCA~ AND RICHARD W. DODSON made up to a nominal ionic strength of approxiRECEIVED JANUARY 5, 1955 mately 0.5. Exact values of the ionic strength canIn a number of studies of the kinetics of electron not be calculated since the equilibrium constants transfer exchange reactions between metal ions in for the formation of the thallium-cyanide complexes aqueous solution it has been found that the rates are unknown. The values are believed to lie in the are affected significantly by the presence of anions range 0.4-0.55 mole/l., except in one case as noted which are capable of forming complexes with one in Table I. Variations in this range are not exof the reactants. Indeed such an anion effect is so pected to have an important effect on the rate. The reaction mixture was maintained a t 30.0 f general that it may be considered a characteristic feature of these oxidation-reduction exchange reac- 0.1' in a water-bath. At intervals aliquots were tions. Thus for example, the rates of the thallous- pipetted from the reaction mixture. Each aliquot c e r o ~ s - c e r i c , ~ferrou~-ferric,~.'0 ~~ euro- was combined with 10 mg. of T1+ carrier, and thalpous-europicl' and antimono~s-antimonic~~~~~ ex- lous chromate was precipitated as earlier described.6 The precipitates were mounted in the form of 1 inch (1) Work supported in part by the U. S. Atomic Energy Commisdiameter discs on filter paper, and were counted on sion a gas-flow proportional counter. (2) A more detailed account of this investigation will appear in Eugcnhario c Q u h i c a (Ria de Janeiro). Results and Discussion (3) On leave from the Oswaldo Cruz Institute, Rio de Janeiro, Brazil. The results were analyzed in terms of the McKay (4) R. J. Prestwood and A. C Wahl, THIS JOURNAL, 71,3137 (1949). f o r m ~ l ain~ the ~ , ~usual ~ way. The expression used (5) G.Harbottle and R. W. Dodson, ibid., 73, 2442 (1951). was ( 6 ) L. Eimer and R. W. Dodson, Brookhaven National Laboratory Quarterly Progress Report, 93(S-8), p. 67, March 1951. (7) J. W. Gryder and R. W. Dodson, THISJOURNAL,73, 2890 (1951). (8) H.C. Hornig and W. F. Libby, J . P h y s . Ckcm., 5 6 , 869 (1952). (9) J. Silverman and R. W. Dodson, ibid., 56, 846 (1952). (10) J. Hudis and A. C. Wahl, THIS JOURNAL, 75, 4153 (1953). (11) D.J . hlejer and C. S.Garner, J . Phys. Chcm., 56, 853 (1952). (12) N. Bonner, THIS JOURNAL, 71, 3909 (1949). (13) H.M. Neumann and H. Brown, Abstracts 125th Meeting ACS, Kansas City, March 24 to April 1, 1954.
where y is the activity of the initially active form (thallous) a t time t, yo and y m are the activities of the thallous fractions a t times zero and infinity respectively, a and b are the over-all concentrations (14) G.Biedermann, A r k . Kcmi. 5 , 441 (1953). (15) We are indebted to Dr. R. W. Stoenner for this preparation.
