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Uranium tetrachloride — aluminum trichloride vapor complex
INORG. HUCL.
CHEM. LETTERS
Yol.
URANIUM TETRACHLORIDE
4,
pp.
-
299-303,
1968,
Pergamon Press.
Printed
In
Greet
Britain.
ALUMINUM TRICHLORIDE VAPOR COMPLEX*
Dieter M. Gruen and Robert L. McBeth Argonne National Laboratory, Argonne~ Illinois 60439 (Recelv~ 22 Feb~a~ 1~8)
Recently, some properties of a neodymium trichloridealuminum chloride vapor complex were described (i).
In addition,
vapor complexes involving aluminum chloride and representative group I chlorides (2)~ group II dichlorides (3~4)~ and 3d transition metal dichlorides (4) have been studied in other laboratories.
The experiments to be discussed here have led to the
spectroscopic identification of a volatile uranium tetrachloridealuminum chloride complex.
These findings suggest that aluminum
chloride is capable of forming gaseous complexes with metal chlorides widely distributed throughout the periodic table (5). A typical experiment~ using apparatus and procedures similar to those described in earlier work (6)~ was conducted as follows: 0.132 g of UCI 4 and 0.52 g of AICI 3 were placed in a 20 cm long~ 25 rm~ I.D.~ 3 rm~ wall thickness, cylindrical quartz cell.
The
evacuated and sealed cell was placed in a resistance heated tube furnace situated in the sample space of a double beam spectrophotometer modified for high-temperature operation.
In the
temperature range, 590°K to 8400K, all of the aluminum chloride was in the vapor phase exerting pressures ranging from 1.7 - 3.0 atm (the A12C16 ~ 2
AICI 3 dissociative equilibrium becomes
*Work performed under the auspices of the U. S. Atomic Energy Commission. 299
MG
UlULMIUM TETRACNLORIDE. ALUMINUM TRICHLORIINE
increasingly significant above
700°K).
brium with solid UCI4(m. p. 863°K).
V°l. 4, Nev$
The vapors were in equili-
In order to determine the
molar absorptivity of the complex, a separate experiment was performed in which 4.5 mg of UCI 4 was added to a cell containing 0.58 g of AICI 3.
The plot of optical density at 8734 cm -I (maximum of
one of the absorption bands of the complex) versus temperature became constant at 625°K and remained constant up to 870°K showing that all of the UCI 4 initially added to the cell was present as vapor complex above 625°K.
From these data one calculates
c8734 cm-I = 25.9. The electronic absorption spectrum of the vapor complex in the range 4,000 - 25,000 cm -I is shown in Fig. i.
For comparison,
the spectrum of pure UCI 4 gas is also shown in Fig. i.
The UCI 4
gas spectrum independently obtained in our laboratory, is in good agreement with that first reported by Morrey, et al.
( 7 ) . The
lower vapor pressure and lower e's of UCI 4 compared with the complex made a correction for light absorption due to uncomplexed UCI 4 unnecessary in the temperature interval of the present measurements.
The partial pressure of the complex, calculated
from the relation Patm = ART c~ where A is the absorbance, and ~ the pathlength, is given in Fig. 2 and is compared with the vapor pressure of UCI4(s)
(8).
It can be seen that the ratio
Pcomplex/PUcl4 is ~ 104 at 623°K (350°C).
This ratio, whose
magnitude depends on the AI2CI 6 pressure in an as yet undetermined way, decreases with increasing temperature because the heat of sublimation of UCI4(s) is larger than the heat of formation of the complex.
1~1. 4, ~
5
UIIAi~M
TETRACHLORIDE
* Ai.UiinIuM
TRiCHLOItlDE
301
O0 ,-4
!
2
• ,.4 ~:~ ~o o .~o0
4-J 4J
~X
~0
!
0
~rj e--i
X
T 0
m_
CO
0
oJ 0
I ~D ~r)
o~1 I'~
cO oJ
~!oJ
0 o~1
~
o~1
(IAIO • 3701AI/~13±17)
cO
0
~0 C~ u~ c~ O~
E
E~
(J
0 ~,-4 r~
302
URANIU/~ T E T R A C H L O R I D E
+3.00
u
I
i
I
• ALUMINUM TRICHLORIDE
I
Yol. 4, No. 5
I
I
I
i
I
I
I
]
+ 2.00
+
1.00
,5,
-'r-
E
0.00
-
1.00
-
(i}
Q)
n.
-
o
_J
-
2.00
A
-3.00
-
-
I
4.00
0.20
0.18
] 0.16
I
0.14
0.12
0.10
102/T oK
Fig.
2.
A.
Vapor pressure
of UCI4(s).
B.
Partial pressures of uranium tetrachloridealuminum chloride vapor complex in a closed cell in which the AI2CI 6 pressure was 1.7 arm at 590°K.
Vol. 4, He. $
URANIUM TETRACHLORIDE
-
ALUMINUM TRICHLORIDE
303
References i.
D. M. GRUEN and H. A. @YE, Inorg. Nucl. Chem. Letters 3, 453 (1967).
2.
E. W. DEWING, J. Am. Chem. Soc. 77, 2639 (1955).
3.
K. N. SEMENENKO, T. N. NAUMOVA, L. N. GOROKHOV, and A. V. NOVOSELOVA, Dokl. Akad. Nauk SSSR 154, 648 (1964).
4.
E. W. DEWING, Nature 214, 483 (1967).
5.
Analogous vapor complexes have now been found involving aluminum bromide and rare earth tribromides.
(D. M. GRUEN and
R. LENGEL, to be published.) 6.
D. M. GRUEN and C. W. DeKOCK, J. Chem. Phys. 45, 455 (1966).
7.
J. R. MORREY, D. G. CARTER, and J. G. GRUBER, J. Chem. Phys. 46, 804 (1967).
8.
The Chemistry of Uranium, J. J. Katz and E. Rabinowitch, eds. NNES VIII, p. 476, McGraw-Hill Book Co. Inc.
(1951).
CHEM. LETTERS
Yol.
URANIUM TETRACHLORIDE
4,
pp.
-
299-303,
1968,
Pergamon Press.
Printed
In
Greet
Britain.
ALUMINUM TRICHLORIDE VAPOR COMPLEX*
Dieter M. Gruen and Robert L. McBeth Argonne National Laboratory, Argonne~ Illinois 60439 (Recelv~ 22 Feb~a~ 1~8)
Recently, some properties of a neodymium trichloridealuminum chloride vapor complex were described (i).
In addition,
vapor complexes involving aluminum chloride and representative group I chlorides (2)~ group II dichlorides (3~4)~ and 3d transition metal dichlorides (4) have been studied in other laboratories.
The experiments to be discussed here have led to the
spectroscopic identification of a volatile uranium tetrachloridealuminum chloride complex.
These findings suggest that aluminum
chloride is capable of forming gaseous complexes with metal chlorides widely distributed throughout the periodic table (5). A typical experiment~ using apparatus and procedures similar to those described in earlier work (6)~ was conducted as follows: 0.132 g of UCI 4 and 0.52 g of AICI 3 were placed in a 20 cm long~ 25 rm~ I.D.~ 3 rm~ wall thickness, cylindrical quartz cell.
The
evacuated and sealed cell was placed in a resistance heated tube furnace situated in the sample space of a double beam spectrophotometer modified for high-temperature operation.
In the
temperature range, 590°K to 8400K, all of the aluminum chloride was in the vapor phase exerting pressures ranging from 1.7 - 3.0 atm (the A12C16 ~ 2
AICI 3 dissociative equilibrium becomes
*Work performed under the auspices of the U. S. Atomic Energy Commission. 299
MG
UlULMIUM TETRACNLORIDE. ALUMINUM TRICHLORIINE
increasingly significant above
700°K).
brium with solid UCI4(m. p. 863°K).
V°l. 4, Nev$
The vapors were in equili-
In order to determine the
molar absorptivity of the complex, a separate experiment was performed in which 4.5 mg of UCI 4 was added to a cell containing 0.58 g of AICI 3.
The plot of optical density at 8734 cm -I (maximum of
one of the absorption bands of the complex) versus temperature became constant at 625°K and remained constant up to 870°K showing that all of the UCI 4 initially added to the cell was present as vapor complex above 625°K.
From these data one calculates
c8734 cm-I = 25.9. The electronic absorption spectrum of the vapor complex in the range 4,000 - 25,000 cm -I is shown in Fig. i.
For comparison,
the spectrum of pure UCI 4 gas is also shown in Fig. i.
The UCI 4
gas spectrum independently obtained in our laboratory, is in good agreement with that first reported by Morrey, et al.
( 7 ) . The
lower vapor pressure and lower e's of UCI 4 compared with the complex made a correction for light absorption due to uncomplexed UCI 4 unnecessary in the temperature interval of the present measurements.
The partial pressure of the complex, calculated
from the relation Patm = ART c~ where A is the absorbance, and ~ the pathlength, is given in Fig. 2 and is compared with the vapor pressure of UCI4(s)
(8).
It can be seen that the ratio
Pcomplex/PUcl4 is ~ 104 at 623°K (350°C).
This ratio, whose
magnitude depends on the AI2CI 6 pressure in an as yet undetermined way, decreases with increasing temperature because the heat of sublimation of UCI4(s) is larger than the heat of formation of the complex.
1~1. 4, ~
5
UIIAi~M
TETRACHLORIDE
* Ai.UiinIuM
TRiCHLOItlDE
301
O0 ,-4
!
2
• ,.4 ~:~ ~o o .~o0
4-J 4J
~X
~0
!
0
~rj e--i
X
T 0
m_
CO
0
oJ 0
I ~D ~r)
o~1 I'~
cO oJ
~!oJ
0 o~1
~
o~1
(IAIO • 3701AI/~13±17)
cO
0
~0 C~ u~ c~ O~
E
E~
(J
0 ~,-4 r~
302
URANIU/~ T E T R A C H L O R I D E
+3.00
u
I
i
I
• ALUMINUM TRICHLORIDE
I
Yol. 4, No. 5
I
I
I
i
I
I
I
]
+ 2.00
+
1.00
,5,
-'r-
E
0.00
-
1.00
-
(i}
Q)
n.
-
o
_J
-
2.00
A
-3.00
-
-
I
4.00
0.20
0.18
] 0.16
I
0.14
0.12
0.10
102/T oK
Fig.
2.
A.
Vapor pressure
of UCI4(s).
B.
Partial pressures of uranium tetrachloridealuminum chloride vapor complex in a closed cell in which the AI2CI 6 pressure was 1.7 arm at 590°K.
Vol. 4, He. $
URANIUM TETRACHLORIDE
-
ALUMINUM TRICHLORIDE
303
References i.
D. M. GRUEN and H. A. @YE, Inorg. Nucl. Chem. Letters 3, 453 (1967).
2.
E. W. DEWING, J. Am. Chem. Soc. 77, 2639 (1955).
3.
K. N. SEMENENKO, T. N. NAUMOVA, L. N. GOROKHOV, and A. V. NOVOSELOVA, Dokl. Akad. Nauk SSSR 154, 648 (1964).
4.
E. W. DEWING, Nature 214, 483 (1967).
5.
Analogous vapor complexes have now been found involving aluminum bromide and rare earth tribromides.
(D. M. GRUEN and
R. LENGEL, to be published.) 6.
D. M. GRUEN and C. W. DeKOCK, J. Chem. Phys. 45, 455 (1966).
7.
J. R. MORREY, D. G. CARTER, and J. G. GRUBER, J. Chem. Phys. 46, 804 (1967).
8.
The Chemistry of Uranium, J. J. Katz and E. Rabinowitch, eds. NNES VIII, p. 476, McGraw-Hill Book Co. Inc.
(1951).