NOTES
1018
solute value of the standard is not known closer than 10%. Therefore, the actinium fluoride neutron emission rate determined experimentally is probably no better than f 15 to 20%. However, since the neutron emission from the fluoride sample, and the theoretical growth curve agreed quite closely over the growth period, and since the theoretical and experimental maximum values are of the same order of .magnitude, one can conclude that the values that were used for computation are approximately correct, and the neutron yields obtained by extrapolation from data in reference six are not unreasonable. Thus, the use of neutron counting techniques for quantitative detection of trace quantities of fluorine in actinium appears feasible. There seems to be no serious objection to extending the technique to the detection of fluorine or other light elements, such as beryllium or boron, in any of the alpha-active heavy elements. We wish t o acknowledge the assistance of Mr. R. D. Joyner and Mr. S. R. Orr, who found time between their regular duties to prepare the actinium fluoride and to perform the calorimetric assay. We are also grateful t q Dr. H. W. Schamp for his assistance with the sealing problem.
*
THE INFRARED SPECTRA OF THREE ALUMINUM ALKOXIDES BY DOSALDL. GUERTIS,STEPHES E. WIBERLEY, WALTERH. HAVER ASD JEROMEGOLDESSOS Contribution f r o m the Walker Laboratory of Rensselaer Polyfechnic Inafitute, T r o y , N . Y . , and The Chemicnl and Radiological Laboratories A r m y Chemical Center, -1Iaryland Keceibed J a n u a v y 2.5, 1966
Infrared absorption near 990 em.-’ in aluminum di-soaps was ascribed to the aluminum-oxygen
Vol. 60
linkage by Scott, et aL1 Ludke, et aL12later showed that this band was associated with the aluminumoxygen-aluminum linkage rather than the aluminum-oxygen-carbon linkage. T o verify this correlation, it appeared of value to investigate the infrared spectra of several aluminum alkoxides. The spectra of aluminum isopropoxide has previously been reported3 but the spectra of the two other alkoxides discussed in this paper are not available. The present work indicates that aluminum-oxygen-carbon linkages give rise to absorption between 1028 to 1070 em.-’. Experimental Alcohols .-Alcohols were stored over Drierite for two weeks, filtered and distilled from calcium hydride. The boiling points and infrared spectra agreed with reported data.4 Preparation and Analysis of A1koxides.-The alkoxides were prepared according to directions in Organic Reactio~is.~ The boiling points of the alkoxides and analytical results for per cent. aluminum are presented in Table I.
TABLE I ANALYSISOF ALUMINUM ALKOXIDES Alkoxide
Isopropoxide Sec. Butoxide 2-Pentoxide
B.p., “C. (mm.) Lit.8 Found
Calcdq” Bound
140 (10)
13.21 13.22
180-181.5 (8) 160 (10)
10.95 11.03
140.5 (8)
....
140-150 (10)
9.35
9.20
Infrared Absorbance Measurements.-Infrared spectra were obtained on a Perkin-Elmer Model 21 double beam recording infrared spectrometer equipped with rock salt optics. Alcohols were measured in a demountable liquid cell without a spacer. Liquid alkoxides were measured in a fixed liquid cell with a 0.025 mm. spacer and in a demountable liquid cell without a spacer to resolve strong bands. Nujol mulls of the solid alkoxides were measured in a demountable liquid cell without a spacer. Potassium bromide windows7 of the solid alkoxides were also prepared, but hydrolysis of the alkoxides occurred in these cases.
Results and Discussion The infrared spectra of the alkoxides and the spectra of the corresponding alcohol in the region of 8 to 12 p are shown in Fig. 1. Table I1 presents the frequencies assigned to the A1-0-C linkage in the alkoxides studied. TABLE I1
100
50
.o
W
FREQUENCIES (cM.-~) ASSOCIATEDWITH THE AI-0-C LINKAGE I N THREE ALKOXIDES
NUM 12- PEN~OXIDE 12
WAVELENGTH
Fig. 1.-Infrared
14
MICRONS,
spectra of three aluminum alkoxides.
Alkoxide
Assignment, cm.-l
Aluminum isopropoxide Aluminum sec-butoxide Aluminum 2-pentoxide
1033 1058 1070
(1) F. A. Scott, J. Goldenson, 8. E. Wiberley and W. H. Bauer T H E JOURNAL, 68, 61 (1954). (2) W.0. Ludke, 6 . E. Wiberley. J. Goldenson and W. H. Bauer, ibid., 69, 222 (1955). (3) J. V. Bell, J. Heisler, H. Tannenbaum and J. Goldenso?, Anal. Chem., 26 1720 (1953). (4) Am. Petroleum Inst., Research Project 44, Carnegie Institute of Technology, ”Catalog of Infrared Spectral Data,” 1950: Sgectrograms 428, 431 and 436. (5) R. Adams, editor-in-chief, “Organic Reactions,” Vol. 11, John Wiley and Sons, Inc., New York, N . Y., 1944, p. 198. (6) “Beilsteins Handbuch der organischen Chemie,” Band 1. Vierte Auflage, 1943. (7) M. M. Stimson and M. J. O’DonneU, J . A m . Chem. Sac., 74, 805 (1952).
July, 1956 As can be noted from Table I1 the frequency shifts with change in inductive effect of the alkane substituent. According to Ingold's8 theory the alkyl groups concerned can be listed in order of electron releasing ability as
