solutions of aluminurn 8-quinolinolate, contrary to the literature references. This deconiposition is worse for U.S.P. chloroform than for either reagent or
Spectrogrades. Oxygen and light together give the most rapid decomposition. Tentatively we believe t h a t chloroform decomposition products,
Table I. Absorbance of Aluminum 8-Quinolinolate (5.0 mg. per 100 ml. of chloroform solution, 390 mp) Absorbance, us. CHCh Darka Chloroform Light* Chloroform Minn A B C D A B Ce utes 0 0 699 0 695 0 685 0 691 0 696 0 697 0 691 0 688 0 699 0 691 0 681 0 686 0 694 0 692 0 685 0 681 10 0 696 0 686 0 674 0 683 0 688 0 681 0 680 0 675 20 0.691 0.683 0.670 ... 0.682 0.673 0.676 ... 30 0.686 0.683 0.667 ... 0,674 0.671 0.673 .., 40 0.685 0.681 ... ... 0.669 0.668 ... ... 50 Chloroform: A, Baker analyzed reagent, 0.6% ethyl alcohol; B, Eastman Organic Chemical, Spectrograde, alcohol stabilized; C, Baker U.S.P., 99.0-99.5% CHC13, balance ethyl alcohol; D, Baker U.S.P. passed through silica gel column. 0 Solution kept in Beckman instrument in total darkness. b Exposed to 60-watt incandescent light, in Beckman 1.00-cm. silica cell, approximately 18 inches from bulb. Light exposure in this case consisted in leaving cell in Beckman a t 390 niG with slit wide oDen. no filter. a , Our absorbance value of 0.699 yields a molar absorptivity of 6.42 X l o 3 compared to Moeller’s value of 6.61 X lo3(3). KO detectable differences were found in the two different aluminum 8-quinolinolate preparations.
probably oxygenated compounds such as phosgene, attack and decompose t h e aluminum chelate. Since BHT does not seem to affect t h e decomposition, i t appears to be non-free-radical in nature. ACKNOWLEDGMENT
The authors thank the Reheis Co., Inc., for a grant which made this work possible. LITERATURE CITED
(1) Kolthoff, I. &I Sandell, ., E. B , “Textbook of Quantitative Inorganic Analysis,” 3rd Gd., p. 320, Maemillan, New York, 1952. ( 2 ) Mrargerum, D. W.,Sprain, W., Banks, C. 1 ., ANAL.CHEM.2 5 , 249 (1953). (3) Moeller, T., Ibid., 15, 270, 346 (1943). (4) Moeller, T., ,-,ohen, J., Ibid., 22, 686 (1950). (5) Moeller, T., Cohen, A. J., J . .4m. Chem. SOC.72, 3546 (1950). (6](Reheis. Co., Berkeley Heights, N. J., Analysis Procedure, Chlorhydrol 50% Solution.” ROBERT H. L I N ~ E L L FREDRIK H. R A A B Department of Chemistry University of Vermont Burlington, Vt.
196. Titanium Dioxide (Brookite), TiO, S. R. YOGANARASIMHAN and C. N. R. RAO, Deportment of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 12, India Weyl (+1 ) has repeated the earlier work of Pauling and Sturdivant (2) on the crystal structure of t h e brookit? modification of titanium dioxide. The results show t h a t brookite belongs to the orthorhombic system with T T h * 5 symmetry. The detailed powder diffraction d a t a of brookite have not been reported. The .2STM cards ( I ) report only a few lines for brookite and the intensities are only visual estimates. T h e authors have now investigated the crystallography of brookite, using a Debye-Scherrer powder camera and a Geiger counter x-ray diffractometer. The procedure of the National Bureau of Standards (3) was employed for the preparation of the samples used with the diffractometer. Brookite samples from hlagnet Cove, Ark., and Canton Uri, Su-itzerland, were used for the study. The samples were found to be pure by chemical and spectrographic analyses. It was made certain by x-ray analysis (Weissenberg pattern) t h a t no traces of anatase and rutile were present in the samples. RECENTLY,
CRYSTALLOGRAPBY Crystal System. Orthorhombic. Space Group. T’his.
X-Ray Diffraction Data Magnet Canton Cove, IJri, r hkl d, A. d , A. 42 210 3.518 3.513 100 111 3.471 3.4.59 ___ 46 2 899 211 2 907 13 2 484 2 482 102 12 2 415 02 1 2 419 15 2 249 202 2 253 11 2 141 221, 410 2 139 8 1 975 1 971 302 26 1 900 1 906 32 1 12 1 855 312 1 857 26 1 695 230 1 696 33 1 666 421 1 668 6r 1 615 1 615 113 I 1 547 213 1 547 6 1 500 331 1 501 10 1 468 132 1 469 8 1 457 1 457 422 1 448 8 313 1 448 9 1 438 123 1 439 2 1 423 611 1 423 4 1 370 040 1 370 1 341 5 332 1 342
Lattice Constants. a = 9.25 f 0.03 A. b = 5.46 =k 0.02 A. c = 5.16 =t0.01 A. Density. 4.07 grams per cc. (x-ray) The powder x-ray diffraction d a t a of the Magnet Cove and Canton Uri samples of brookite are summarized in t h e table. T h e d a t a of the two samples agree well with each other and are also in fair agreement with those reported in the ASTRI cards ( 1 ) . ACKNOWLEDGMENT
The authors thank ILI. R. A. Rao for his keen interest. LITERATURE CITED
(1) Am.
SOC.Testing Materials, Index
1957. (2) Pauling, L., Sturdivant J. H., 2. Krist. 68, 239 (1928). (3) Swanson, H. E., Tatge, E., Natl. Bur. Standards, Circ. 539 (1953). (4) Weyl, V. R., Z. Krist. 111, 401 (1959). CRYSTALLOGRAPHIC data for publication in this section should be sent t? W. C. McCrone, 501 East 32nd St., Chicago 16, Ill. VOL. 33, NO. 1, JANUARY 1961
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