Aluminum
Η
. J . BECHER
Lithium Aluminu m Hydrid e
LiAlH4I. 4 LiH + AICI3 = L1AIH4 + 3 L i C l
31.8 133.4 38,0 1272
F o r t h e r e a c t i o n b e t w e e n LiH a n d A 1 C 13 to o c c u r to a n o t i c e a b l e e x t e n t , t h e t h i c k , h a r d l u m p s of l i t h i u m h y d r i d e m u s t b e g r o u n d t o a v e r y fine p o w d e r and t h e n s i e v e d . T h i s t r e a t m e n t i s p e r f o r m e d u n d e r n i t r o g e n . A v e r y r e a c t i v e e t h e r s u s p e n s i o n of LiH i s o b t a i n e d if t h e m a t e r i a l i s w e t - g r o u n d w i t h a n h y d r o u s e t h e r in a s p e c i a l b a l l m i l l (K. Z i e g l e r et al.) and u s e d i m m e d i a t e l y .
A f r e s h s u s p e n s i o n of 23.5 g. (2.96 m o l e s ) of LiH in 200 m l . of e t h e r i s i n t r o d u c e d (with e x c l u s i o n of m o i s t u r e ) into a t h r e e - n e c k f l a s k p r o v i d e d w i t h a d r o p p i n g funnel, a r e f l u x c o n d e n s e r a n d a s t i r r e r . A s o l u t i o n of 71.2 g. (0.534 mole) of A 1 C 13 in 300 m l . of e t h e r i s t h e n a d d e d in d r o p s w i t h v i g o r o u s s t i r r i n g . T h e r e a c t i o n s t a r t s i m m e d i a t e l y , a s shown by t h e b o i l i n g of t h e e t h e r . T h e r a t e i s k e p t u n i f o r m by a d j u s t m e n t of t h e a d d i t i o n r a t e . When a l l t h e A 1 C 13 s o l u t i o n h a s b e e n a d d e d , s t i r r i n g i s c o n t i n u e d u n t i l t h e r e a c t i o n h a s s u b s i d e d , and t h e m i x t u r e i s left t o s t a n d f o r s o m e t i m e . T h e c o n t e n t s of t h e f l a s k a r e t h e n f i l t e r e d , u s i n g n i t r o g e n p r e s s u r e , t h r o u g h a f r i t t e d g l a s s f i l t e r , a n d t h e c l e a r f i l t r a t e i s c o n c e n t r a t e d at a t m o s p h e r i c p r e s s u r e u n t i l it h a s a s y r u p y c o n s i s t e n c y . T h e r e s i d u a l e t h e r m a y b e e v a p o r a t e d in v a c u u m at 70°C. T h e y i e l d of L i A l H4, b a s e d on A1C13, i s about 85%.
Insufficient g r i n d i n g of t h e LiH m a y p r e v e n t t h e r e a c t i o n f r o m s t a r t i n g s p o n t a n e o u s l y , o r f r o m going to c o m p l e t i o n , and l e a d to s u d d e n , e x p l o s i v e b u r s t s of r e n e w e d a c t i v i t y ; in s u c h c a s e s t h e r e a c t i o n i s s t a r t e d by a d d i n g 200 m l . of e t h e r , followed by a s o l u tion of 3 g. of L i A l H4 in 30 m l . of e t h e r , t o t h e finely d i v i d e d L i H . The s u b s e q u e n t p r o c e d u r e i s t h e s a m e a s d e s c r i b e d a b o v e . A c c o r d ing to W i b e r g , a s l i g h t q u a n t i t y of iodine m a y b e u s e d a s an i n i t i a t o r i n s t e a d of t h e L i A l H4.
8 0 5
8 0 6 Η . J . B E C H E R
Π. 4 LiH + AlBrs = LiAlH4 + 3 LiBr
31.8 266.7 38.0 260.5
A c c o r d i n g to W i b e r g , t h e difficulties involved in t h e p r e p a r a t i o n of sufficiently r e a c t i v e LiH a r e not e n c o u n t e r e d if A l B r3 i s u s e d i n s t e a d of A1C13. In t h i s c a s e , c o a r s e LiH c a n b e u s e d :
An e t h e r s o l u t i o n of A l B r3 i s p r e p a r e d by adding s m a l l p o r t i o n s of t h e m a t e r i a l (total 267 g. = 1 mole) to 750 m l . of e x t r e m e l y p u r e , d r y e t h e r in a f l a s k c o o l e d w i t h i c e - s a l t m i x t u r e . A 3 3 - g . p o r t i o n (4.1 m o l e s ) of c o a r s e l y g r o u n d LiH i s p l a c e d in a t h r e e - n e c k f l a s k with a r e f l u x c o n d e n s e r , a s t i r r e r and a d r o p p i n g funnel. T h e h y d r i d e i s c o v e r e d with 250 m l . of e t h e r , and t h e A l B r3 s o l u t i o n i s allowed to r u n in; t h e a d d i t i o n t a k e s one t o two h o u r s . T h e s t i r r e d m i x t u r e i s t h e n h e a t e d to t h e b o i l i n g point of e t h e r and k e p t a t t h i s t e m p e r a t u r e for a few h o u r s . T h e L i B r and u n r e a c t e d LiH p r e c i p i t a t e on c o o l i n g . The s o l u t i o n i s r a p i d l y d e c a n t e d t h r o u g h a l a y e r of g l a s s wool in a funnel. T h e f i l t r a t e o b t a i n e d c o n s i s t s of an e t h e r s o l u t i o n of L i A l H4 s a t u r a t e d with L i B r . T h e s o l u t i o n m a y b e s t a b i l i z e d by s t o r i n g it o v e r a s m a l l quantity of L i H .
PROPERTIES:
C o l o r l e s s s o l i d , s t a b l e in d r y a i r at r o o m t e m p e r a t u r e . T h e e t h e r s o l u t i o n i s u s e d in i n o r g a n i c and o r g a n i c c h e m i s t r y a s a r e d u c i n g and h y d r o g e n a t i n g a g e n t .
REFERENCES:
A. E. F i n h o l t , A. C. Bond and Η. I. S c h l e s i n g e r , J . A m e r . C h e m . S o c 6 9 , 1200 (1947).
J. M a h e , J . R o l l e t and A. W i l l e m a r t , B u l l . Soc. C h i m . F r a n c e , M e m . (5), 16, 481 (1949).
K. Z i e g l e r , H. G. G e l l e r t , H. M a r t i n and K. N a g e l , L i e b i g s Ann.
C h e m . 589, 91 (1954).
E . W i b e r g , R. B a u e r , M. S c h m i d t a n d R. U s o n , Z . N a t u r f o r s c h . 6 b , 393 (1951).
E. W i b e r g and M. S c h m i d t , Z. N a t u r f o r s c h . 7_b, 59 (1952).
Calciu m Aluminu m Hydrid e
Ca(AlH4)24CaH2 + 2A1C13 = Ca(AlH4)2 + 3CaCl2
168,4 266,8 102.1 333.0
A f r e s h l y p r e p a r e d s o l u t i o n of A 1 C 13 in t e t r a h y d r o f u r a n i s added t o a s u s p e n s i o n of finely g r o u n d c a l c i u m h y d r i d e in t h e s a m e
s o l v e n t . A 30% e x c e s s of C a H2 s h o u l d b e u s e d . T h e m i x t u r e i s r e f l u x e d u n d e r n i t r o g e n f o r s e v e r a l h o u r s in a f l a s k p r o v i d e d with a s t i r r e r and a r e f l u x c o n d e n s e r . W h e n t h e s o l u t i o n h a s c o o l e d , it i s r a p i d l y s u c t i o n f i l t e r e d and t h e s o l v e n t i s slowly d i s t i l l e d f r o m t h e f i l t r a t e u n d e r n i t r o g e n . T h e s o l i d r e s i d u e e v o l v e s f u r t h e r t e t r a h y d r o f u r a n w h e n h e a t e d to 80-90°C in a s p i r a t o r v a c u u m . T h e n e a r l y c o l o r l e s s r e s i d u e f r o m t h i s t r e a t m e n t s t i l l c o n t a i n s about 50-60% t e t r a h y d r o f u r a n , in a d d i t i o n to t h e C a ( A l H4)2. T h e h y d r i d e c o n t e n t c a n b e r a i s e d t o 60% by t r e a t m e n t in h i g h v a c u u m .
B e f o r e t h e C a H2 c a n b e u s e d in t h e r e a c t i o n , it s h o u l d b e g r o u n d f o r 8 - 2 4 h o u r s in a p o r c e l a i n b a l l m i l l . T h e g r i n d i n g and s u b s e q u e n t p r e p a r a t i o n of t h e t e t r a h y d r o f u r a n s u s p e n s i o n a r e done in t h e a b s e n c e of m o i s t u r e ; t h i s e n s u r e s sufficient r e a c t i v i t y of t h e h y d r i d e . B e f o r e h e a t i n g t h e r e a c t i o n m i x t u r e it i s r e c o m m e n d e d t h a t a few c r y s t a l s of iodine o r , b e t t e r s t i l l , a s m a l l quantity of a p r e v i o u s l y p r e p a r e d t e t r a h y d r o f u r a n s o l u t i o n of C a ( A l H4)2 b e a d d e d . T h e A 1 C 13 s h o u l d b e s u b l i m e d b e f o r e u s e . At w o r s t , it m a y b e only s l i g h t l y y e l l o w .
PROPERTIES:
T h e t e t r a h y d r o f u r a n s o l u t i o n of C a ( A l H4)2i s r a p i d l y d e c o m p o s e d by m o i s t u r e . E v e n on s t o r a g e in a c l o s e d v e s s e l , c o n s i d e r a b l e d e c o m p o s i t i o n o c c u r s a f t e r s o m e w e e k s .
REFERENCE:
W. Schwab and K. W i n t e r s b e r g e r , Z. N a t u r f o r s c h . 8_b, 690 (1953).
Polymeri c Aluminu m Hydrid e
( A l H3) n- x O ( C2H5)23 LiAlH4 + A1C13 = 4/n(AlH3)n + 3LiCl
313.9 133.4 120-0 127.2
A s o l u t i o n of 1.137 g. of L i A l H4 in 30 m l . of e t h e r i s p l a c e d in a s m a l l t h r e e - n e c k f l a s k fitted w i t h a n i t r o g e n inlet t u b e , a r e f l u x c o n d e n s e r and a d r o p p i n g funnel. T h e a p p a r a t u s i s t h o r o u g h l y f l u s h e d with d r y n i t r o g e n , and a s o l u t i o n of 1.33 g. of A 1 C 13 in 20 m l . of e t h e r i s d r o p p e d in. T h e e n s u i n g r e a c t i o n i s v i g o r o u s , but f a l l s off r a p i d l y . A f i l t e r t u b e w i t h a s e a l e d - i n f r i t t e d d i s k i s s u b s t i t u t e d f o r t h e funnel, a n d t h e s o l u t i o n i s f i l t e r e d out of t h e f l a s k . The e t h e r i s p a r t l y e v a p o r a t e d f r o m t h e f i l t r a t e by s l o w l y r a i s i n g t h e t e m p e r a t u r e to 90°C in high v a c u u m . T h e w h i t e r e s i d u e h a s t h e c o m p o s i t i o n ( Α 1 Η3)η · χ CKCjgHg) 2, t h e r a t i o of A 1 H3 to e t h e r
8 0 8 Η . J . B E C H E R
d e p e n d i n g on t h e d u r a t i o n and t e m p e r a t u r e of e v a p o r a t i o n ; it r a n g e s f r o m 2.8 : 1 to 4.8 : 1 . T h e p r o d u c t c a n n o t b e o b t a i n e d e n t i r e l y f r e e of e t h e r , s i n c e h y d r o g e n slowly s p l i t s off a t t e m p e r a t u r e s e x c e e d ing 90°C.
I m m e d i a t e l y a f t e r c o m p l e t i o n of t h e r e a c t i o n , t h e s o l u t e c o n s i s t s of m o n o m e r i c A 1 H3. After a s h o r t w h i l e , h o w e v e r , a p o l y m e r with a high e t h e r c o n t e n t b e g i n s t o s e p a r a t e .
REFERENCES:
A. E. F i n h o l t , A. C. Bond and H. J . S c h l e s i n g e r , J . A m e r . C h e m . Soc. 6 9 , 1200 (1947).
E. W i b e r g , H. G r a f and R. U s o n , Z . a n o r g . a l l g . C h e m . 272, 221 (1953).
Aluminu m Chlorohydrid e
A12C1SH3A1H3 + AICI3 = A12C13H3
30.0 133,4 163,4
A f r e s h e t h e r s o l u t i o n of m o n o m e r i c A 1 H3 i s p r e p a r e d a s d e s c r i b e d in t h e p r e v i o u s s e c t i o n a n d t h e L i C l p r e c i p i t a t e i s r e m o v e d by f i l t r a t i o n o r c e n t r i f u g a t i o n . A s o l u t i o n of A 1 C 13 in a s m a l l v o l u m e of e t h e r i s i m m e d i a t e l y a d d e d to t h e c l e a r A 1 H3 s o l u t i o n . T h e two r e a c t a n t s (A1H3 and A1C13) a r e a d d e d in e q u i m o l a r a m o u n t s . T h e a d d i t i o n of t h e A 1 C 13 p r e v e n t s t h e p o l y m e r i z a t i o n of t h e A 1 H3. T h e e t h e r c a n t h e n b e c o m p l e t e l y e v a p o r a t e d f r o m t h e s o l u t i o n , y i e l d i n g a w a t e r - c l e a r liquid, w h i c h d i s t i l l s a t 80°C without d e c o m p o s i t i o n in high v a c u u m . It h a s t h e c o m p o s i t i o n of A 12C 13H3.
SYNONYM:
T r i c h l o r o d i a l a n e .
PROPERTIES:
T h e e t h e r s o l u t i o n of t h e c o m p o u n d b e h a v e s c h e m i c a l l y a s a m i x t u r e of s o l u t i o n s of A 1 H3 and A 1 C 13. It h a s t h e a d v a n t a g e of b e i n g m o r e s t a b l e t h a n a n e t h e r s o l u t i o n of p u r e A 1 H3.
REFERENCE:
E. W i b e r g and M. Schmidt, Z. N a t u r f o r s c h . 6 b , 3 3 3 , 4 5 8 , 459 (1951).
Aluminu m Hydrid e Trimethylaminat e
A1H3 · 2N(CH3)3,A1H3 · N(CH3)3 A1H3 · 2N(CH3)3A1H3 + 2 N(CH3)3 = A1H3 · 2 N(CH3)3
30.0 118,2 148.2
A s in t h e p r e c e d i n g two p r e p a r a t i o n s , a f r e s h e t h e r e a l s o l u t i o n of m o n o m e r i c A 1 H3 i s p r e p a r e d and i t s c o n c e n t r a t i o n a d j u s t e d t o 0.5 M. A 1 5 - m l . p o r t i o n of a 1 Μ e t h e r s o l u t i o n of a n h y d r o u s t r i m e t h y l a m i n e i s a d d e d to 15 m l . of t h e h y d r i d e s o l u t i o n . If a s l i g h t t u r b i d i t y r e s u l t s , t h e m i x t u r e s h o u l d b e c e n t r i f u g e d . T h e c l e a r s o l u t i o n i s left to s t a n d f o r one half h o u r . T h e e t h e r i s t h e n v a c u u m d i s t i l l e d , s t a r t i n g a t —78°C a n d s l o w l y r a i s i n g t h e t e m p e r a t u r e t o +20°C. T h e r e s i d u e , a w h i t e p o w d e r , i s slowly s u b l i m e d in high v a c u u m into a r e c e i v i n g f l a s k c o o l e d with an i c e - s a l t m i x t u r e ; t h e s u b l i m a t i o n t e m p e r a t u r e i s 40°C. T h e c o m p o s i t i o n of t h e s u b l i m a t e i s A 1 H3' 2 N ( C H3)3.
PROPERTIES:
C o l o r l e s s c r y s t a l s . M . p . 95°C; d e c o m p o s e s a b o v e 100°C.
F u m e s in a i r and i s v i g o r o u s l y h y d r o l y z e d in w a t e r . Soluble in t e t r a h y d r o f u r a n , e t h e r and b e n z e n e .
A1H3 · N(CH3)3
T h e c o m p o u n d i s p r e p a r e d a n a l o g o u s l y , but u s i n g e q u i m o l a r q u a n t i t i e s of t h e h y d r i d e a n d t h e a m i n e . T h e w h i t e p o w d e r left in t h e f l a s k a f t e r r e m o v a l of t h e e t h e r s u b l i m e s b e t w e e n 50 and 60°C (1 m m . ) . T h e p r o d u c t c o n s i s t s of c o l o r l e s s c r y s t a l s w h i c h h a v e t h e c o m p o s i t i o n A 1 H3 · N ( C H3) 3.
PROPERTIES:
M . p . 76°C. O t h e r w i s e s i m i l a r to Α 1 Η3· 2 N ( C H3)3.
REFERENCE:
E . W i b e r g , H. Graft and R. U s o n , Z . a n o r g . a l l g . C h e m . 272, 221 (1953).
Diethylaluminu m Bromid e
Al(C2H5)2Br2A1 + Mg + 4C2H5Br = 2Al(C2H5)2Br + MgBr2
54.0 24.3 435.9 330.1 184.1
T h e r e a c t i o n i s c a r r i e d out in a o n e - l i t e r , t h r e e - n e c k f l a s k equipped w i t h a s t i r r e r , a r e f l u x c o n d e n s e r and a d r o p p i n g funnel,
8 1 0 Η . J . B E C H E R
a s w e l l a s an inlet t u b e for d r y , o x y g e n - f r e e n i t r o g e n . T h e f l a s k i s filled w i t h 107 g. of t u r n i n g s o b t a i n e d f r o m an alloy of 30%
m a g n e s i u m and 70% a l u m i n u m . S m a l l q u a n t i t i e s of i o d i n e and ethyl b r o m i d e a r e a d d e d . After a s h o r t t i m e t h e h a l i d e c a n b e o b s e r v e d to r e a c t with t h e m e t a l . T h e r e a c t i o n f l a s k i s t h e n i m m e r s e d in a n oil b a t h and a t o t a l of 496 g. of e t h y l b r o m i d e i s a d d e d d r o p w i s e d u r i n g 2.5 h o u r s . T h e f l a s k i s t h e n h e a t e d to 120-140°C and kept at t h i s t e m p e r a t u r e for one h o u r to e n s u r e c o m p l e t i o n of t h e r e a c t i o n . T h e p r o d u c t i s s e p a r a t e d f r o m t h e m a g n e s i u m b r o m i d e by v a c u u m d i s t i l l a t i o n , u s i n g a n oil p u m p , and i s r e d i s t i l l e d in v a c u u m (2 m m . , 75°C). All o p e r a t i o n s m u s t b e c a r r i e d out u n d e r n i t r o g e n . T h e y i e l d i s 370 g. of A l ( C3H5)2B r , c o n t a m i n a t e d with 2% A l C2H5B r2.
REFERENCE:
A. von G r o s s e and J . M. Mavity, J . O r g . C h e m . 5, 106 (1940).
Triethylaluminu m
A1(C2H5)3Sodium w i r e (50 g.) i s i n t r o d u c e d u n d e r n i t r o g e n into a t h r e e - n e c k f l a s k fitted w i t h a s t i r r e r , a r e f l u x c o n d e n s e r and a n i t r o g e n inlet t u b e . T h e n 150 g. of A l ( C2H5)2B r i s a d d e d d r o p w i s e . T h e flask i s h e a t e d to 105°C and a v i g o r o u s r e a c t i o n s o o n b e g i n s . T h e m i x t u r e s t a r t s to boil and e x t e r n a l c o o l i n g i s n e c e s s a r y . A s soon a s t h e r e a c t i o n q u i e t s down, an a d d i t i o n a l 186 g. of A l ( C2H c 5)2B r i s a d d e d . T h e t e m p e r a t u r e i s slowly r a i s e d to 200°C and m a i n t a i n e d t h e r e for 10 h o u r s , with c o n s t a n t s t i r r i n g . T h e f l a s k i s t h e n c o o l e d to r o o m t e m p e r a t u r e and 2 g. of s o d i u m w i r e i s a d d e d to e n s u r e c o m p l e t i o n of t h e d e h a l o g e n a t i o n . S t i r r i n g i s r e s u m e d , and t h e t e m p e r a t u r e i s a g a i n r a i s e d to 150°C and h e l d for 1.5 h o u r s . T h e A 1 ( C2H5)3 f o r m e d i s d i s t i l l e d f r o m t h e r e a c t i o n m i x t u r e in v a c u u m (2 m m . ) . F u r t h e r p u r i f i c a t i o n i s a c h i e v e d by f r a c t i o n a t i o n in a v a c u u m P o d b i e l n i a k c o l u m n ; t h e p r o d u c t b o i l i n g b e t w e e n 128 and 130°C and 50 m m . i s c o l l e c t e d .
PROPERTIES:
F o r m u l a w e i g h t 1 1 4 . 2 . Spontaneously f l a m m a b l e . I m m e d i a t e l y h y d r o l y z e d by m o i s t u r e t o Al(OH) 3 and C2H6.
REFERENCES:
A. von G r o s s e , J . M. Mavity, J . O r g . C h e m . 5, 106 (1940). R e c e n t p r e s s u r e p r o c e s s e s f o r a l u m i n u m t r i a l k y l s s t a r t i n g w i t h Al, H2 and o l e f i n s , a s w e l l a s t h e i r a p p l i c a t i o n s to t h e l o w - p r e s s u r e p o l y m e r i z a t i o n of e t h y l e n e , a r e given in K. Z i e g l e r et a l . , Angew. C h e m . 67, 424 (1955).
Triethylaluminu m Etherat e AI(C2H5)3 · 0 ( C2H5)2
A 2 4 - g . s a m p l e of E l e c t r o n m e t a l t u r n i n g s (15.1% Al, t h e r e m a i n d e r Mg a n d t r a c e s of Si) i s c o v e r e d w i t h 400 m l . of e t h e r in a t h r e e - n e c k f l a s k fitted w i t h a r e f l u x c o n d e n s e r , a s t i r r e r and a d r o p p i n g funnel; 150 g. of e t h y l b r o m i d e i s a d d e d by d r o p s . T h e r e a c t i o n m a y b e i n i t i a t e d by t h e a d d i t i o n of a few c r y s t a l s of i o d i n e . W h i l e t h e r e a c t i o n i s in p r o g r e s s , t h e e t h e r s h o u l d b e b o i l i n g at a u n i f o r m r a t e . W h e n t h e m e t a l h a s c o m p l e t e l y d i s s o l v e d , t h e e t h e r i s quickly r e m o v e d , l e a v i n g a s o l i d r e s i d u e f r o m w h i c h t h e t r i e t h y l a l u m i n u m e t h e r a t e i s d i s t i l l e d at 140-180°C into an i c e - c o o l e d r e c e i v e r . T h e d i s t i l l a t i o n i s c a r r i e d out slowly u n d e r n i t r o g e n a t 1 4 - 1 6 m m . , u s i n g a n oil b a t h . T h e p r o d u c t i s r e d i s t i l l e d at 112°C and 16 m m .
PROPERTIES:
F o r m u l a w e i g h t 1 8 8 . 3 . C o l o r l e s s liquid, s e n s i t i v e t o a i r and m o i s t u r e . B . p . 112°C (16 m m . ) .
REFERENCES:
E . K r a u s e and B. W e n d t , B e r . d t s c h . c h e m . G e s . 56, 466 (1923).
Ε. B. B a k e r and H. S. S i s l e r , J . A m e r . C h e m . Soc. 7 5 , 4828 (1953).
Diethylaluminu m Hydrid e A1(C2H5)2H
A1(C2H5)2C1 + LiH = A1(C2H5)2H + LiCl
120.6 7.9 128.2 42.5
T h e e t h e r c o m p l e x of d i e t h y l a l u m i n u m c h l o r i d e i s p r e p a r e d f i r s t by a d d i n g d r o p w i s e o n e half m o l e of A1C13, d i s s o l v e d in s o m e e t h e r , to o n e m o l e of A 1 ( C2H 5 ) 3 · 0 ( C2H 5 ) 2. W h e n t h e evolution of h e a t c e a s e s , t h e e x c e s s s o l v e n t i s e v a p o r a t e d a n d t h e A 1 ( C2H 5)2C 1 e t h e r a t e i s d i s t i l l e d in v a c u u m . A 7 6 - g . p o r t i o n of t h i s p r o d u c t i s d i l u t e d w i t h 120 m l . of a b s o l u t e e t h e r a n d p l a c e d in a 5 0 0 - m l . , t h r e e - n e c k f l a s k w h i c h h a s b e e n f l u s h e d w i t h d r y n i t r o g e n . A s u s p e n s i o n of L i H in e t h e r (62 m l . , 7 Μ in LiH) i s p r e p a r e d in a d r o p p i n g funnel u n d e r a n i t r o g e n b l a n k e t a n d a l l o w e d t o flow into t h e f l a s k . L i t h i u m c h l o r i d e s e p a r a t e s a n d t h e r e a c t i o n m i x t u r e b o i l s . T o w a r d t h e end of t h e r e a c t i o n , s t i r r i n g i s a p p l i e d a n d t h e m i x t u r e i s h e a t e d to 40°C f o r 15 m i n u t e s m o r e . T h e L i C l
8 1 2 Η . J . B E C H E R
r a p i d l y p r e c i p i t a t e s w h e n t h e f l a s k i s a l l o w e d to c o o l . T h e c l e a r s u p e r n a t a n t i s t h e n s a m p l e d w i t h a p i p e t t e a n d t e s t e d f o r h a l o g e n . If t h e t e s t i s p o s i t i v e , a few m o r e d r o p s of t h e LiH s u s p e n s i o n a r e a d d e d . T h e s u p e r n a t a n t s h o u l d b e j u s t h a l o g e n f r e e but s h o u l d not c o n t a i n any a p p r e c i a b l e a m o u n t of e x c e s s L i . T h e m i x t u r e i s t h e n c e n t r i f u g e d and t h e c l e a r s o l u t i o n d e c a n t e d . T h e p r e c i p i t a t e i s w a s h e d with a s m a l l v o l u m e of e t h e r , w h i c h i s t h e n e v a p o r a t e d in an a s p i r a t o r v a c u u m , t h e l a s t t r a c e s b e i n g r e m o v e d at 50°C.
T h e r e s i d u a l A 1 ( C2H5)2H i s d i s t i l l e d in high v a c u u m , holding t h e flask in a b a t h m a i n t a i n e d at 80°C o r l o w e r . It i s c o l l e c t e d in a r e c e i v e r c o o l e d to — 20°C. T h e d i s t i l l a t e i s a w a t e r - c l e a r liquid.
T h e e n t i r e p r e p a r a t i o n should b e c a r r i e d out without i n t e r r u p t i o n . The p r e s e n c e of s o l i d d e p o s i t s d u r i n g t h e d i s t i l l a t i o n of t h e c r u d e p r o d u c t l o w e r s t h e y i e l d , w h i c h o t h e r w i s e m a y b e a s high a s 70%.
PROPERTIES:
A i r - and m o i s t u r e - s e n s i t i v e liquid. B . p . 55-56°C ( 1 0 "3 m m . ) .
REFERENCE:
K. Z i e g l e r , H. G. G e l l e r t , H. M a r t i n and K. Nagel, L i e b i g s Ann.
C h e m . 589, 9 1 - 1 2 1 (1954).
Aluminu m Chlorid e
A1C13Al + 3HC1 = AICI3 + 1V2H2 27.0 109.4 133.4 3.0
I. One end of a l a r g e d i a m e t e r V y c o r t u b e (25 to 40 m m . ) i s i n s e r t e d t h r o u g h one of two h o l e s b o r e d in a c o r k c l o s i n g a w i d e - n e c k f l a s k . T h e s e c o n d h o l e h o l d s a t u b e l e a d i n g to t h e hood. T h e c o r k c a n b e d i s p e n s e d with if t h e r e a c t i o n t u b e c a n b e m a d e to fit tightly into t h e n e c k of a l o n g - n e c k , r o u n d - b o t t o m f l a s k . T h e r e a c t i o n t u b e i s p l a c e d in an e l e c t r i c f u r n a c e . T h e d i s t a n c e b e t w e e n t h e hot z o n e and t h e r e c e i v e r flask s h o u l d not b e l o n g e r t h a n 8 c m . , to p r e v e n t plugging of t h e t u b e by t h e s u b l i m a t e . T h e c o r k i s p r o t e c t e d f r o m t h e h e a t by an a s b e s t o s w r a p p i n g . A p o r c e l a i n b o a t c o n t a i n i n g a l u m i n u m t u r n i n g s o r p o w d e r i s i n s e r t e d in t h e r e a c t i o n t u b e . G a s e o u s HC1 i s then p a s s e d t h r o u g h f r o m t h e end o p p o s i t e t h e r e c e i v e r . The r u b b e r t u b i n g c o n n e c t i o n s s h o u l d b e a s s h o r t a s p o s s i b l e . When t h e a i r h a s b e e n c o m p l e t e l y d i s p l a c e d by t h e HC1, t h e f u r n a c e i s slowly h e a t e d u n t i l a w h i t e m i s t b e g i n s to a p p e a r . T h e flow of HC1 i s t h e n i n c r e a s e d and t h e t e m p e r a t u r e r a i s e d to
p r e v e n t p r e m a t u r e c o n d e n s a t i o n of t h e s u b l i m a t e . T h e r e a c t i o n i s t h e n a l l o w e d to c o n t i n u e u n t i l t h e a l u m i n u m h a s b e e n c o m p l e t e l y c o n s u m e d .
II. C o m m e r c i a l A1C13, w h i c h u s u a l l y c o n t a i n s i r o n and t r a c e s of oxygen due to h y d r o l y s i s , m a y b e p u r i f i e d by t h e following p r o c e d u r e . T h e c r u d e m a t e r i a l i s m i x e d with about 10% by w e i g h t of a l u m i n u m t u r n i n g s and t h e m i x t u r e i s p l a c e d in a s u b l i m a t i o n flask with a s i d e a r m t h r o u g h w h i c h a m o d e r a t e s t r e a m of d r y HC1 i s fed d u r i n g t h e s u b l i m a t i o n . A s h o r t , w i d e , c u r v e d t u b e c o n n e c t s t h e s u b l i m a t i o n flask w i t h t h e r e c e i v i n g f l a s k a n d t h e e n t i r e s y s t e m i s p r o t e c t e d a g a i n s t m o i s t u r e by a d r y i n g t u b e . F u r t h e r p u r i f i c a t i o n i s by r e s u b l i m a t i o n in a n i t r o g e n a t m o s p h e r e , u s i n g t h e r e c e i v e r of t h e f i r s t s t e p a s a s u b l i m a t i o n flask; t h e r e s t of a p p a r a t u s i s s i m i l a r .
PROPERTIES:
M.p. 193°C, b . p . 180°C; d (17°C) 2 . 4 6 5 , d (200°C, liq.) 1.31.
C o l o r l e s s , t r a n s p a r e n t , h e x a g o n a l p l a t e s . V e r y h y g r o s c o p i c .
REFERENCES:
I. F . S t o c k h a u s e n and L. G a t t e r m a n n , B e r . d t s c h . c h e m . G e s . 2 5 , 3521 (1892).
II. D. D. E l e y and H. W a t t s , J . C h e m . Soc. (London) 1952, 1914.
Aluminu m Bromid e
AlBr3I. Al + l72Br2 = AlBr3
27.0 239.7 266.7
V e r y p u r e A l B r3 m a y b e p r e p a r e d in t h e a p p a r a t u s shown in F i g . 2 4 4 . T h e b o t t o m of t h e r e a c t i o n f l a s k i s c o v e r e d with a l a y e r of g l a s s wool, and t h e d e s i r e d quantity of v e r y p u r e , d e g r e a s e d d r y a l u m i n u m t u r n i n g s i s p l a c e d on t o p . N i t r o g e n , d r i e d o v e r P2Os, i s i n t r o d u c e d at e and e s c a p e s a t / . W h e n t h e l a s t t r a c e s of m o i s t a i r h a v e b e e n flushed out, s t o p c o c k β i s c l o s e d and t h e s t r e a m of n i t r o g e n i s p a s s e d f r o m g t o / . D r y b r o m i n e i s t h e n a d d e d f r o m t h e d r o p p i n g funnel into f l a s k a. T h e r a t e of addition i s a d j u s t e d s o t h a t t h e h e a t of r e a c t i o n m a i n t a i n s t h e r e s u l t i n g A l B r3 at a t e m p e r a t u r e sufficient for r e f l u x i n g in t h e m i d d l e s e c t i o n of t h e a i r c o n d e n s e r . A c o n s i d e r a b l e e x c e s s of Al should r e m a i n a f t e r a l l t h e b r o m i n e h a s b e e n a d d e d . T h e r e a c t i o n f l a s k i s t h e n h e a t e d u n t i l t h e liquid flowing down f r o m b i s c o l o r l e s s .
8 1 4 H . J . B E C H E R
T h e d i r e c t i o n of t h e n i t r o g e n s t r e a m i s r e v e r s e d , a d r y i n g t u b e filled w i t h P2Ob i s a t t a c h e d at g, and t h e A l B r3 i s d i s t i l l e d f r o m a into r e c e i v e r o. W h e n t h e d i s t i l l a t i o n i s c o m p l e t e , t h e r e c e i v e r i s d i s c o n - n e c t e d without i n t e r r u p t i n g t h e n i t r o g e n flow a n d i m m e d i a t e l y c l o s e d t i g h t l y .
II. When c o l o r l e s s A l B r3 i s not r e - q u i r e d , t h e p r o c e d u r e d e s c r i b e d in I m a y b e c a r r i e d out in a r e g u l a r d i s - t i l l a t i o n f l a s k with a d r o p p i n g funnel f o r b r o m i n e . T h e b o t t o m of t h e f l a s k i s a g a i n c o v e r e d with g l a s s wool and t h e a l u m i n u m p l a c e d on t o p . T h e flask i s p r e h e a t e d o v e r an open f l a m e to about 100°C. T h e d r o p w i s e a d d i t i o n of B r2 i s t h e n c a r r i e d out at s u c h a r a t e t h a t it i s r a p i d l y c o n s u m e d . T h e t e m p e r a t u r e s h o u l d r e m a i n below t h e b o i l i n g point of A l B r3. W h e n t h e addition i s c o m p l e t e t h e p r o d u c t i s d i s t i l l e d t h r o u g h a d e - s c e n d i n g t u b e into a r e c e i v e r .
F i g . 244. P r e p a r a t i o n of a l u m i n u m b r o m i d e .
PROPERTIES:
C o l o r l e s s , shiny l a m e l l a e . H y d r o l y z e s in m o i s t a i r . R e a c t s violently with w a t e r (caution!). Soluble in m a n y o r g a n i c s o l v e n t s . M.p. 97.5°C, b . p . 255°C; d (18°C) 3.205, d (100°C, liq.) 2 . 6 4 .
REFERENCES:
D. G. N i c h o l s o n , P . K. W i n t e r and H. F i n e b e r g in: F . A u d r i e t h , I n o r g . S y n t h e s e s , Vol. Ill, New Y o r k - L o n d o n 1950, p . 3 3 . W. Biltz and A. Voigt, Z. a n o r g . a l l g . C h e m . 126, 48 (1923).
W. K l e m m , W. Tilk and S. von M u l l e n h e i m , Z. a n o r g . a l l g . C h e m . 176, 14 (1928).
Aluminu m Iodid e AII3
Al + I V 2 12 = AII3
27 0 380.7 407,7
I. A l u m i n u m t u r n i n g s and a few c r y s t a l s of iodine a r e p l a c e d in a C 02- f i l l e d f l a s k and h e a t e d until r e a c t i o n b e g i n s . M o r e I2 i s t h e n added u n t i l only a s m a l l a m o u n t of a l u m i n u m r e m a i n s . T h e
r e a c t i o n p r o d u c t i s k e p t a l i t t l e l o n g e r in t h e m o l t e n s t a t e and t h e n t r a n s f e r r e d u n d e r n i t r o g e n into an A n s c h u t z d i s t i l l a t i o n flask, w h e r e it i s slowly d i s t i l l e d in an oil p u m p v a c u u m . T h e p u m p i s p r o t e c t e d a g a i n s t i o d i n e v a p o r by two w a s h b o t t l e s filled with a c t i v a t e d c h a r c o a l .
II. A 2 0 - g . p o r t i o n of d r i e d and s u b l i m e d iodine i s d i s s o l v e d in 80 m l . of C S2 a n d h e a t e d w i t h 3.5 g. of s h e e t a l u m i n u m in a f l a s k p r o v i d e d with a r e f l u x c o n d e n s e r . When t h e r e a c t i o n i s o v e r , t h e m i x t u r e i s f i l t e r e d , t h e f i l t r a t e i s h e a t e d o v e r a w a t e r b a t h (caution: do not u s e a n open flame!) to d i s t i l l off m o s t of t h e C S2, and t h e c o n c e n t r a t e d r e s i d u e i s c o o l e d . A l u m i n u m iodide c r y s - t a l l i z e s out. T h e c r y s t a l s a r e s u c t i o n - f i l t e r e d , w a s h e d with h e x a n e and d r i e d at 100°C. T h e p r o d u c t r e t a i n s a s l i g h t y e l l o w - b r o w n t i n g e .
PROPERTIES:
C o l o r l e s s l e a f l e t s if p u r e . M o i s t u r e - s e n s i t i v e . D e c o m p o s e s t o I2 and A 1203 on h e a t i n g in a i r . Soluble in C S2, a l c o h o l and e t h e r . M . p . 191°C, b . p . 382°C; d (17°C) 3.948; d (200°C, liq.) 3.26.
REFERENCES:
I. W. Biltz and A. Voigt, Z. a n o r g . a l l g . C h e m . 126, 50 (1923).
W. K l e m m , W. Tilk and S. von Miillenheim, Z . a n o r g . a l l g . C h e m . 176, 15 (1928).
II. W. N e s p i t a l , Z. p h y s . C h e m . (B) 16, 164 (1932).
Aluminu m Chlorid e Hydrat e
A1C13 · 6 H20At 0°C, A 1 C 13- 6 H20 i s s l i g h t l y s o l u b l e (21 m g . / l O O m l . ) in s a t u r a t e d a q u e o u s HCl and i s t h e r e f o r e e a s i l y i s o l a t e d f r o m s u c h a s o l u t i o n . T h e a l u m i n u m i s d i s s o l v e d in c o n c e n t r a t e d HCl and t h e s o l u t i o n i s t r a n s f e r r e d into a t h r e e - n e c k f l a s k fitted with a s t i r r e r , an inlet t u b e for HCl g a s and an o u t l e t t u b e . T h e f l a s k i s c o o l e d t o 0°C and HCl g a s i s i n t r o d u c e d into t h e c o n t i n u o u s l y s t i r r e d and c o o l e d s o l u t i o n u n t i l it i s s a t u r a t e d . T h e inlet t u b e s h o u l d not dip into t h e s o l u t i o n , s i n c e it m i g h t b e c o m e c l o g g e d with s a l t , but sufficient a b s o r p t i o n of t h e HCl i s e n s u r e d by v i g o r o u s s t i r r i n g . A w a s h b o t t l e with c o n c e n t r a t e d H2S 04 c o n n e c t e d t o t h e o u t l e t of t h e f l a s k s e r v e s to i n d i c a t e t h e p r o g r e s s of t h e s a t u r a t i o n . T h e p r e c i p i t a t e d h y d r a t e i s r a p i d l y s u c t i o n - f i l t e r e d and, w h i l e s t i l l cold, w a s h e d with s o m e e t h e r and d r i e d on a c l a y p l a t e .
REFERENCE:
W. F i s c h e r and W. Seidel, Z. a n o r g . a l l g . C h e m . 247, 333 (1941).
8 1 6 H . J . B E C H E R
Sodiu m Tetrachloroaluminat e
NaAlCl4NaCl + AICI3 = NaAlCl4
58.4 133.4 191.8
T h e r e a c t i o n i s c a r r i e d out in a P y r e x v e s s e l ( F i g . 245), which should b e a s c o m p a c t a s p o s s i b l e . T h e s t o i c h i o m e t r i c
a m o u n t s of C P . NaCl and f r e s h l y s u b - l i m e d A 1 C 13 a r e i n t r o d u c e d into t h e p e a r - s h a p e d p a r t of t h e r e a c t i o n v e s s e l . T h e filling i s done u n d e r n i t r o g e n and t h e v e s s e l s h o u l d b e v e r y c l e a n and d r y . A m e l t i n g point c a p i l l a r y i s t h e n affixed u n d e r n e a t h t h e g r o u n d joint; t h e a p p a - r a t u s i s e v a c u a t e d t o a high v a c u u m and F i g . 2 4 5 . P r e p a r a t i o n t o r c h - s e a l e d . It i s t h e n i m m e r s e d a s of s o d i u m t e t r a c h l o r o - d e e p l y a s p o s s i b l e in a n oil b a t h at a l u m i n a t e . 2 0 0 - 2 4 0 ° C . T h e A1C13, w h i c h t e n d s t o
s u b l i m e onto t h e cool p a r t s of t h e w a l l , i s d r i v e n b a c k by p a s s i n g a l u m i n o u s f l a m e o v e r t h e c o n d e n s a t e s p o t s . When t h e flask c o n t e n t s h a v e b e c o m e a n e a r l y c l e a r m e l t , they a r e p o u r e d hot into t h e s i d e f l a s k of t h e v e s s e l . T h e p r o d u c t s o l i d i f i e s on c o o l i n g .
PROPERTIES:
C o l o r l e s s , c r y s t a l l i n e m a t e r i a l . M . p . 156°C.
REFERENCES:
H. G e r d i n g and H. Houtgraaf, R e c . T r a v . C h i m . P a y s - B a s 72, 21 (1953).
N. C. B a e n z i g e r , A c t a C r y s t . (London) 4 , 216 (1951).
Tetrachloroalumini c Aci d Dietherat e
HAIC14 · 2 0 ( C2H5)2HCl + AICI3 + 2 0 ( C2Hs)2 = HA1C14 · 2 0(C2H5)2
36.5 133.4 148.2 318.1
Dry HCl g a s i s p a s s e d t h r o u g h a b s o l u t e e t h e r u n t i l a c o n c e n - t r a t e d s o l u t i o n i s o b t a i n e d . Slightly l e s s t h a n t h e s t o i c h i o m e t r i c a m o u n t of a n h y d r o u s A 1 C 13 i s a d d e d with c o o l i n g a n d s h a k i n g . A
c l e a r oil s e p a r a t e s and s l o w l y f o r m s w h i t e c r y s t a l s when t h e m i x t u r e i s c o o l e d to — 20°C w i t h s t i r r i n g . T h e c r y s t a l s a r e f i l t e r e d u n d e r n i t r o g e n on a s i n t e r e d g l a s s f i l t e r and w a s h e d with e t h e r . T h e c o m p o u n d i s s t a b l e on s t o r a g e if m o i s t u r e i s e x c l u d e d .
A n a l o g o u s l y , A l B r3 and H B r m a y b e r e a c t e d to f o r m H A l B r4« 2 0 ( C2H 5 )2, w h i c h i s o b t a i n e d in t h e f o r m of an o i l .
REFERENCE:
E, W i b e r g , M. S c h m i d t and A. G. G a l i n o s , Angew. C h e m . 66, 443 (1954).
Aluminu m Chlorid e Ammoniat e
A1C13 · N H3AICI3 + NH3 = AICI3 · NH3
133.4 17.0 150.4
T h o r o u g h l y d r i e d a m m o n i a i s p a s s e d o v e r f r e s h l y s u b l i m e d AICI3 in a long, 2 0 - 4 0 m m . d i a m e t e r g l a s s t u b e . H i g h e r a m m o n i - a t e s a r e f o r m e d a s t h e c o n t e n t s m e l t . T h e r e a c t i o n t u b e i s s w e p t w i t h n i t r o g e n and slowly h e a t e d in a f u r n a c e f r o m 190°C t o 360°C at w h i c h t e m p e r a t u r e t h e m o n o a m m o n i a t e A 1 C 13- N H3 i s o b t a i n e d . It i s p u r i f i e d by v a c u u m d i s t i l l a t i o n at 2 m m . , with t h e flask on an oil b a t h a t 2 0 5 - 2 1 0 ° C .
PROPERTIES:
M o i s t u r e - s e n s i t i v e , c o l o r l e s s s u b s t a n c e . M . p . 130°C.
REFERENCES:
E. T i e d e , M. T h i m a n n and K. S e n s s e , B e r . d t s c h . c h e m . G e s . 6 1 , 1568 (1928).
H. G e r d i n g a n d H. Houtgraaf, R e c . T r a v . C h i m . P a y s - B a s 74, 15 (1955).
Aluminu m Chloride-Sulfu r Dioxid e Adduc t
AICI3 · s o2AICI3 + S 02 = AICI3 · so2
133.4 64.0 197.4
A c o m b u s t i o n t u b e i s c h a r g e d with A1C13, w h i c h s h o u l d b e p u r e and f r e e of i r o n . An e x c e s s of S 02 i s c o n d e n s e d on t h e c h l o r i d e .
8 1 8 H . J . B E C H E R
No m o i s t u r e s h o u l d b e p r e s e n t d u r i n g t h e r e a c t i o n . T h e t u b e i s t o r c h - s e a l e d and h e a t e d t o 50°C for about half an h o u r . T h e e x c e s s S 02 i s t h e n a l l o w e d to e s c a p e by h e a t i n g t h e s e a l e d end of t h e t u b e . T h e r e s i d u e i s a v i s c o u s , c o l o r l e s s liquid, w h i c h g r a d u a l l y s o l i d i f i e s . Its c o m p o s i t i o n i s A 1 C 13- S 02.
REFERENCES:
O, Ruff, B e r . d t s c h . c h e m . G e s . 3 5 , 4954 (1902).
H. G e r d i n g and E. Smit, Z. p h y s . C h e m . (B) 5 1 , 204 (1942).
Aluminu m Chloride-Thiony l Chlorid e Adduc t
Al2Cle · SOCl22 A1C13 + SOCl2 = A12C16 · SOCl2
266.7 119.0 385.7
A n h y d r o u s A 1 C 13 i s d i s s o l v e d a t r o o m t e m p e r a t u r e in e x c e s s S O C l2. When l a r g e q u a n t i t i e s a r e to b e p r e p a r e d , t h e s o l u b i l i t y of t h e A 1 C 13 c a n b e i n c r e a s e d by h e a t i n g t h e s o l u t i o n . T h e e x c e s s S O C l2 i s d i s t i l l e d f r o m t h e r e d - b r o w n s o l u t i o n a n d t h e t e m p e r a t u r e of t h e b a t h in w h i c h t h e f l a s k i s i m m e r s e d i s t h e n slowly r a i s e d . T h e f i r s t f r a c t i o n i s d i s c a r d e d . T h e A 12C 16' S O C l2 d i s t i l l s o v e r at 212 t o 216°C in t h e f o r m of oily d r o p l e t s w h i c h solidify in t h e r e c e i v i n g f l a s k . T h e p r o d u c t i s p u r i f i e d by f r a c t i o n a t i o n , b . p . 2 1 4 - 2 1 5 ° C .
REFERENCE:
H. Hecht, Z. a n o r g . a l l g . C h e m . 254, 44 (1947).
Aluminu m Chloride-Phosphoru s Pentachlorid e Adduc t
AICI3 · PCI5
AICI3 + PCI5 = AICI3 · PCI5
133.3 208.3 341.6
I. A l u m i n u m c h l o r i d e and m o r e t h a n t h e s t o i c h i o m e t r i c a m o u n t of P C I Β a r e p l a c e d in a t h i c k - w a l l t u b e s e a l e d at one end. T h e t u b e i s e v a c u a t e d u s i n g a n o i l p u m p and t h e o t h e r e n d i s s e a l e d . T h e t u b e i s t h e n h e a t e d u n t i l t h e s o l i d t u r n s into a c l e a r m e l t . After cooling, t h e t u b e i s opened u n d e r n i t r o g e n and t h e c o n t e n t s a r e p o u r e d into a s m a l l d i s t i l l a t i o n f l a s k . V a c u u m i s a p p l i e d a n d t h e t e m p e r a t u r e slowly r a i s e d to 300°C to r e m o v e t h e e x c e s s P C 15.
II. A p r e c i p i t a t e of A 1 C 13- P C 15 i s p r o d u c e d on m i x i n g a c h l o r o - f o r m s o l u t i o n of PCI 5 and A 1 C 13.
PROPERTIES:
C o l o r l e s s p o w d e r . M . p . 380°C (383°C, II). Soluble in n i t r o - b e n z e n e . T h i s s o l u t i o n c o n d u c t s a c u r r e n t and p r o b a b l y c o n t a i n s t h e i o n s A I C I 4 and P C 14.
REFERENCES:
I. W. F i s c h e r and O, J u b e r m a n n , Z . a n o r g . a l l g . C h e m . 2 3 5 , 345 (1938).
II. Y a . A. F i a l k o v and Y a . B . B u r y a n o v , Doklady Akad. Nauk.
SSSR 92, 585 (1953).
Aluminu m Bromide-Hydroge n Sulfid e Adduc t
AIBr3 · H2SAlBr3 + H2S = AlBr3 · H2S
266,7 34,1 300,8
A l u m i n u m b r o m i d e i s d i s s o l v e d in liquid H2S w i t h e x c l u s i o n of m o i s t u r e . W h e n s o l u t i o n i s c o m p l e t e , t h e e x c e s s H2S i s e v a p o - r a t e d . A l t e r n a t i v e l y , d r y H2S g a s m a y b e i n t r o d u c e d into a s o l u t i o n of A l B r3 in C S2 and t h e p r e c i p i t a t e d c r y s t a l s f i l t e r e d with e x c l u - s i o n of m o i s t u r e .
PROPERTIES:
C o l o r l e s s , m o i s t u r e - s e n s i t i v e c r y s t a l s . M . p . 103°C in a c l o s e d t u b e . S t r u c t u r e : Al t e t r a h e d r a l l y s u r r o u n d e d by 3 B r and 1 S.
REFERENCES:
W. Biltz and E . K e u n e c k e , Z . a n o r g . a l l g . C h e m . 147, 174 (1925).
J . J a k u b s o h n , Z. p h y s . C h e m . 118, 32 (1925).
A r m i n W e i s s , P . P l a s s and A l a r i c h W e i s s , Z . a n o r g . a l l g . C h e m . 2 8 3 , 390 (1956).
Aluminu m lodide-Hexaammoniat e
A1I3 · 6 N H3A1I8 + 6 NH3 = AII3 · 6 NH3
407.7 102.2 509.9
A p p r o x i m a t e l y 1 g. of c o a r s e l y g r o u n d , p u r e A 1 I3 i s p l a c e d in a t a r e d d r y f l a s k and w e i g h e d . A s l o w n i t r o g e n s t r e a m i s p a s s e d
8 2 0 Η · J . B E C H E R
t h r o u g h a t r a p c o n t a i n i n g d r y , liquid a m m o n i a at —40°C, and i s t h e n i n t r o d u c e d into t h e f l a s k with t h e A 1 I3, w h i c h i s k e p t at — 70°C t h r o u g h o u t t h e r e a c t i o n . T h e a m m o n i a i s a b s o r b e d by t h e iodide, and a fine, w h i t e p o w d e r f o r m s . P e r i o d i c w e i g h i n g i s u s e d a s a c h e c k for t h e q u a n t i t a t i v e a b s o r p t i o n of s i x m o l e s of N H3 for e a c h m o l e of A 1 I3 p r e s e n t .
If t h e c o n c e n t r a t i o n of a m m o n i a in t h e n i t r o g e n i s too high, o r if t h e c o o l i n g i s not efficient enough, t h e r e a c t i o n m a y b e c o m e s o v i g o r o u s t h a t t h e iodide will m e l t and p a r t i a l l y s u b l i m e . P a r t i a l a m m o n o l y s i s of t h e A 1 I3 m a y a l s o o c c u r .
REFERENCE:
W. L. Lloyd T a y l o r , E . G r i s w o l d and J . K l e i n b e r g . J . A m e r . C h e m . Soc. 77, 294 (1955).
Aluminu m Hydroxid e
α - Α 1( Ο Η )3 ( H Y D R A R G I L L I T E )
I. A l u m i n u m h y d r o x i d e ( C P . o r b e t t e r ) i s d i s s o l v e d with m o d e r a t e h e a t i n g in s o d i u m h y d r o x i d e s o l u t i o n ( s a t u r a t e d in t h e cold) u n t i l s a t u r a t i o n i s a t t a i n e d . T h e s o l u t i o n i s d i l u t e d w i t h w a t e r to a d e n s i t y of 1.1, s u c t i o n - f i l t e r e d t h r o u g h h a r d f i l t e r p a p e r , and s t o r e d f o r two w e e k s in a c l o s e d v e s s e l . T h e m o t h e r l i q u o r i s d e c a n t e d f r o m t h e p r e c i p i t a t e of Al(OH) 3 f o r m e d . T h e r e s i d u e i s d i g e s t e d for s e v e r a l d a y s with c o l d w a t e r and t h e n w a s h e d w i t h hot w a t e r u n t i l no a l k a l i n e r e a c t i o n i s d e t e c t a b l e with l i t m u s . T h e p r o d u c t i s d r i e d f i r s t o v e r C a C l2, t h e n o v e r P205. T h e e n t i r e p r e p a r a t i o n i s c a r r i e d out in P y r e x g l a s s w a r e .
II. A l u m i n u m h y d r o x i d e i s p r e c i p i t a t e d f r o m s o l u t i o n by a c o l d solution of ( N H4)sC 03; t h e c r y s t a l s a r e t h o r o u g h l y w a s h e d on a leaf f i l t e r and a d d e d in s m a l l p o r t i o n s to a 50% NaOH s o l u t i o n u n t i l no f u r t h e r s o l u t i o n o c c u r s . T h e g r e a t e r p a r t of t h e s o l u t i o n i s f i l t e r e d . T h e r e m a i n d e r , which c o n t a i n s a s m a l l quantity of u n d i s s o l v e d a l u m i n u m h y d r o x i d e , i s u s e d t o s e e d t h e f i l t r a t e . W e l l - d e v e l o p e d c r y s t a l s of h y d r a r g y l l i t e f o r m in about eight d a y s . They a r e t h e n w a s h e d f r e e of a l k a l i .
PROPERTIES:
P o o r a d s o r p t i v i t y . C o n v e r t e d into b o e h m i t e (AlOOH) a t 180 t o 200°C. d (20°C) 2 . 4 2 4 .
REFERENCES:
I. R. F r i c k e and B. W u l l h o r s t , Z . a n o r g . a l l g . C h e m . 2 0 5 , 127 (1932).
II. W. Biltz a n d K. A. L e h r e r , Z . a n o r g . a l l g . C h e m . 172, 299 (1928).
/?-Al(OH)3 (BAYERITE)
I. A l u m i n u m h y d r o x i d e ( C P . o r b e t t e r ) i s d i s s o l v e d w i t h m o d e r a t e h e a t i n g in s o d i u m h y d r o x i d e s o l u t i o n ( s a t u r a t e d in t h e cold) u n t i l s a t u r a t i o n i s a t t a i n e d . T h e s o l u t i o n i s diluted w i t h w a t e r t o a d e n s i t y of 1.15 and s u c t i o n - f i l t e r e d t h r o u g h h a r d f i l t e r p a p e r . C a r b o n dioxide i s t h e n b u b b l e d t h r o u g h t h e f i l t r a t e f o r t h r e e d a y s . T h e m o t h e r l i q u o r i s d e c a n t e d f r o m t h e r e s u l t i n g p r e c i p i t a t e ; t h e s u b s e q u e n t t r e a t m e n t i s i d e n t i c a l to t h a t d e s c r i b e d f o r h y d r a r - g i l l i t e (Γ). T h e t h o r o u g h l y w a s h e d a n d d r i e d r e s i d u e i s p u r e b a y e r i t e .
II. P u r e a l u m i n u m r i b b o n i s c u t into s t r i p s , d e g r e a s e d and r i n s e d w i t h f r e s h l y d i s t i l l e d a c e t o n e . T h e p i e c e s a r e c o v e r e d with a l a y e r of a m a l g a m by a s h o r t dip in a 0.1 Ν s o l u t i o n of H g C l2 and t h o r oughly w a s h e d with d i s t i l l e d w a t e r , followed by a final r i n s i n g w i t h d o u b l e - d i s t i l l e d w a t e r . T h e p i e c e s a r e t h e n t r a n s f e r r e d to a P y r e x f l a s k c l o s e d off with a s o d a - l i m e t u b e , a n d c o v e r e d w i t h d o u b l e - d i s t i l l e d w a t e r . W h i t e f l a k e s of b a y e r i t e f o r m a f t e r a few d a y s .
Initially, t h e p r o d u c t o b t a i n e d by p r o c e d u r e II i s a m o r p h o u s a c c o r d i n g t o i t s x - r a y p a t t e r n ; h o w e v e r , a f t e r 2 5 - 3 0 h o u r s , t h e b a y e r i t e l i n e s b e g i n t o a p p e a r in t h e p o w d e r p a t t e r n .
PROPERTIES:
H e x a g o n a l c r y s t a l s . C o n s i d e r e d t o b e a m e t a s t a b l e m o d i f i c a t i o n of Al(OH)3. I n d u s t r i a l Al(OH)3, w h i c h i s m a d e by s t i r r i n g s e e d e d a l u m i n u m h y d r o x i d e s o l u t i o n s , i s chiefly h y d r a r g i l l i t e . P r e c i p i t a t i o n f r o m a c i d s o l u t i o n , on t h e o t h e r hand, y i e l d s e x c l u s i v e l y a n a m o r p h o u s p r o d u c t when c a r r i e d out in t h e cold, a n d chiefly b o e h m i t e (α-ΑΙΟΟΗ) when hot s o l u t i o n s a r e u s e d .
REFERENCES:
R. F r i c k e and B . W u l l h o r s t , Z . a n o r g . a l l g . C h e m . 2 0 5 , 127 (1932).
H. S c h m a h , Z. N a t u r f o r s c h . 1, 323 (1946).
J . B o h m , Z. a n o r g . a l l g . C h e m . 149, 203 (1925).
R. F r i c k e , Z. a n o r g . a l l g . C h e m . 166, 244 (1927); 1 7 5 , 249 (1928).
«-ΑΙΟΟΗ (BOEHMITE)
I. A s d e s c r i b e d in m e t h o d II f o r p r e p a r a t i o n of b a y e r i t e , C P . a l u m i n u m i s c o a t e d w i t h a l a y e r of a m a l g a m and t h o r o u g h l y r i n s e d w i t h d o u b l e - d i s t i l l e d w a t e r in a g r o u n d g l a s s f l a s k w i t h a r i s e r t u b e . W h e n t h e w a t e r i s b r o u g h t to a b o i l , a v i o l e n t r e a c t i o n e n s u e s w h i c h , h o w e v e r , d i e s down b e f o r e t h e a l u m i n u m h a s b e e n e n t i r e l y c o n s u m e d . T h e b o e h m i t e o b t a i n e d i s s e p a r a t e d by d e c a n t a t i o n and d r i e d o v e r C a C l2, followed by d r y i n g o v e r P205.
822 H . J . B E C H E R
II. A l u m i n u m h y d r o x i d e p r e c i p i t a t e d in t h e c o l d with a m m o n i a solution i s c o v e r e d with w a t e r in an a u t o c l a v e and h e a t e d for two h o u r s at 200°C. P u r e b o e h m i t e i s f o r m e d .
PROPERTIES:
B o e h m i t e i s t h e chief c o n s t i t u e n t of b a u x i t e . It i s c o n v e r t e d into d i a s p o r e by h e a t i n g it in t h e p r e s e n c e of NaOH for s e v e r a l d a y s at 350°C in an a u t o c l a v e . N a t u r a l d i a s p o r e i s a d d e d a s a s e e d i n g m a t e r i a l [V. K. D r u s h i n i d a , Doklady Akad. Nauk SSSR, N.S., 88, 133 ( 1 9 5 3 ) ] .
REFERENCE:
I. R. F r i c k e and K. J o c k e r s , Z . a n o r g . a l l g . C h e m . 262, 3 (1950).
II. J . B o h m , Z. a n o r g . a l l g . C h e m . 149, 203 (1925).
H. G i n s b e r g and M. K o s t e r , Z. a n o r g . a l l g . C h e m . 2 7 1 , 4 1 (1952).
Aluminu m Oxid e
«-Al203 (CORUNDUM)
T h e c o m p o u n d i s p r e p a r e d by h e a t i n g a l u m i n u m h y d r o x i d e o r α - Α 1203 to a b o v e 1100°C. D i a s p o r e u n d e r g o e s r a p i d c o n v e r s i o n above 500°C.
PROPERTIES:
R h o m b o h e d r a l c r y s t a l s . M . p . 2050°C.
/?-AI203
T h e β f o r m c r y s t a l l i z e s f r o m m o l t e n a l u m i n u m o x i d e c o n t a i n i n g up to 5% of an a l k a l i o x i d e . T h e t r a n s i t i o n t a k e s p l a c e at a t e m p e r a t u r e not m u c h below t h e m e l t i n g point of c r y o l i t e (1020°C) when a m i x t u r e of c r y o l i t e and α - Α 1203 i s a n n e a l e d . T h e a f o r m i s c o n v e r t e d into β - Α 1203 a f t e r a n n e a l i n g a m i x t u r e c o n t a i n i n g 15-20% c r y o l i t e for 20 h o u r s .
PROPERTIES:
A l w a y s c o n t a i n s a s m a l l a m o u n t of a l k a l i . It i s t h e r e f o r e o c c a s i o n a l l y c o n s i d e r e d t o b e a v e r y a l u m i n u m - r i c h a l k a l i a l u m i - n a t e . Hexagonal c r y s t a l s .
REFERENCE:
H. Saalfeld, Z. a n o r g . a l l g . C h e m . 286, 174 (1956).
y-Al203
R e c e n t i n v e s t i g a t i o n s h a v e e s t a b l i s h e d t h a t a n n e a l i n g of a l u m i n u m h y d r o x i d e s (with t h e e x c e p t i o n of d i a s p o r e ) at t e m p e r a t u r e s b e t w e e n 400 and 1000°C y i e l d s not only y - A l203, but a s e r i e s of v a r i o u s p h a s e s (χ, η , κ, δ - Α 1203) , a l l of w h i c h p r o b a b l y c o n t a i n s o m e r e s i d u a l w a t e r t o s t a b i l i z e t h e r e s p e c t i v e l a t t i c e s . A s f a r a s r a n g e of e x i s t e n c e and p r e p a r a t i v e c o n d i t i o n s for t h e s e m o d i f i c a t i o n s i s c o n c e r n e d , t h e o r i g i n a l p a p e r s should b e c o n s u l t e d .
REFERENCES:
H. C. Stumpf, A. S. R u s s e l and J . W. N e w s o m e , Ind. E n g . C h e m . 4 2 , 1398 (1950).
M. R. T e r i t a n , C o m p t . R e n d . Hebd. S e a n c e s A c a d . Sci. 230, 1677 (1950).
S t r u c t u r e R e p o r t s 1 3 , 225 (1950).
H. Thibon, J . C h a r r i e r a n d R. T e r t i a n , B u l l . Soc. C h i m . F r a n c e , (Mem) (5) 18, 384 (1951).
Μ. Κ. B. Day a n d V. J . Hill, N a t u r e (London) 170, 539 (1952).
Aluminu m Sulfid e
A12S3I. 2A1 + 3 H2S = A12S3 + 3 H2
54.0 1022 150.2
A l u m i n u m t u r n i n g s a r e p l a c e d in a c o r u n d u m b o a t i n s e r t e d in a q u a r t z o r h a r d p o r c e l a i n t u b e . One end of t h e t u b e i s c o n n e c t e d to a g e n e r a t o r of p u r e , d r y H2S ; t h e o t h e r end l e a d s to t h e hood.
T h e t u b e i s p l a c e d in a f u r n a c e and H2S i s p a s s e d t h r o u g h . T h e t e m p e r a t u r e d u r i n g t h e f i r s t five h o u r s i s 6 0 0 - 6 3 0 ° C , a n d f o r t h e following 12 h o u r s , 1000°C. T h e p r o d u c t c o n s i s t s of 9 0 - 9 4 % a l u m i n u m sulfide w h i c h s t i l l c o n t a i n s s o m e u n r e a c t e d a l u m i n u m and 1-3% o x y g e n . H i g h e r r e a c t i o n t e m p e r a t u r e s l e a d to a h i g h e r oxygen c o n t e n t , b e c a u s e t h e p r o d u c t r e a c t s with t h e c o r u n d u m of t h e b o a t .
II. 2A1 + 3 S = A12S3
54.0 96.2 150.2
A s t o i c h i o m e t r i c m i x t u r e of a l u m i n u m filings and s u l f u r p o w d e r i s p l a c e d in a g r a p h i t e c r u c i b l e a n d c o v e r e d w i t h s o m e e x c e s s s u l f u r . T h e r e a c t i o n i s s t a r t e d by a s h o r t c i r c u i t b e t w e e n t h e b o t t o m of t h e c r u c i b l e a n d a c a r b o n e l e c t r o d e i m m e r s e d in t h e
824 H . J . B E C H E R
c r u c i b l e . T h e r e a c t i o n m a y a l s o b e i n i t i a t e d with a b u r n i n g m a g n e s i u m s t r i p . After t h e r e a c t i o n i s o v e r , t h e p r o d u c t i s p l a c e d in a c a r b o n b o a t o r c r u c i b l e and h e a t e d in v a c u u m f o r s i x h o u r s to 1150°C to r e m o v e e x c e s s a l u m i n u m . T h e m o l t e n m a s s i s then allowed t o cool s l o w l y . C r y s t a l s 1-3 m m . t h i c k a r e o b t a i n e d . See a l s o t h e p r o c e d u r e f o r d e u t e r i u m sulfide, p . 1 3 4 .
PROPERTIES:
Y e l l o w i s h p o w d e r o r c r y s t a l s ; e x c e s s a l u m i n u m g i v e s t h e c o m p o u n d a g r a y t i n g e . H y d r o l y z e d by w a t e r t o H2S and A l ( O H )3.
REFERENCES:
W, K l e m m , K. G e i e r s b e r g e r , B . S c h a e l e r and H. Mindt, Z . a n o r g . a l l g . C h e m . 2 5 5 , 288 (1948); c i t e s e a r l i e r r e f e r e n c e s .
J. F l a h a u t , C o m p t . R e n d . Hebd. S e a n c e s A c a d . Sci. 232, 334 (1951).
Aluminu m Sulfite
BASIC ALUMINUM SULFITE, AI203 · 2 S 02 · H20
Sulfur dioxide i s i n t r o d u c e d into a s u s p e n s i o n of Al(OH) 3 in w a t e r u n t i l a c l e a r s o l u t i o n i s o b t a i n e d . T h e l a t t e r i s t h e n p l a c e d in a flask c l o s e d with a B u n s e n v a l v e . T h e f l a s k i s h e a t e d to 78-80°C w i t h c o n s t a n t s h a k i n g . A m a g n e t i c s t i r r e r m a y b e u s e d . Sulfur dioxide i s e v o l v e d in t h e p r o c e s s , a s l i g h t p o s i t i v e p r e s s u r e b e i n g m a i n t a i n e d by t h e v a l v e . C r y s t a l l i z a t i o n s e t s in s u d d e n l y and i s e s s e n t i a l l y c o m p l e t e a f t e r four h o u r s . T h e s o l i d p r o d u c t i s f i l t e r e d and d r i e d u n d e r v a c u u m . It c o n s i s t s of Α 1203· 2 S 02- 3 H20 . H e a t i n g to 68 t o 90°C u n d e r v a c u u m l i b e r a t e s w a t e r until t h e c o m p o s i t i o n A 1203 · 2 S 03 · 1 HaO i s a t t a i n e d .
PROPERTIES:
F o r m u l a weight 2 4 8 . 0 8 . H e a t i n g a b o v e 100°C c a u s e s d e c o m p o s i t i o n with evolution of S 02 and w a t e r .
REFERENCE:
E . R o s e n k r a n z and G. F . Hiittig, Z. a n o r g . a l l g . C h e m . 2 2 6 , 126 (1936).
NEUTRAL ALUMINUM SULFITE, Al2Os · 3 S 02 · x H20
A c o n c e n t r a t e d a q u e o u s s o l u t i o n of a l u m i n u m s u l f i t e i s p r e p a r e d a c c o r d i n g to t h e d i r e c t i o n s in t h e p r e c e d i n g m e t h o d a n d e v a p o r a t e d
o v e r P205 in a d e s i c c a t o r . T h e Ρ205 s h o u l d b e r e n e w e d s e v e r a l t i m e s . Sulfur dioxide i s p a s s e d t h r o u g h t h e d e s i c c a t o r d u r i n g t h e e n t i r e d r y i n g p r o c e s s , w h i c h t a k e s about 1 0 - 1 4 d a y s .
PROPERTIES:
W h i t e p o w d e r with v a r i a b l e w a t e r c o n t e n t .
REFERENCE:
W. F i s c h e r a n d E . B u r g e r , Z . a n o r g . a l l g . C h e m . 2 5 1 , 355 (1943).
Aluminu m Selenid e
Al2Se3
2A1 + 3 S e - A l2S e3 54.0 236.9 290,9
I. P u r e , d r y a l u m i n u m p o w d e r (30 g.) i s g r o u n d t o g e t h e r with 50 g.
of finely divided, d r y p r e c i p i t a t e d s e l e n i u m . T h e n 5 g. of t h e m i x t u r e i s t r a n s f e r r e d into a t h i c k - w a l l , 2 0 0 - m l . c l a y c r u c i b l e p r o v i d e d with a l i d . T h e c r u c i b l e i s p l a c e d in t h e hood a n d a s m a l l p i e c e of b u r n i n g m a g n e s i u m s t r i p i s d r o p p e d in to i g n i t e t h e m i x t u r e . T h e c r u c i b l e i s i m m e d i a t e l y c o v e r e d a g a i n . At i n t e r v a l s of a few s e c o n d s t h e lid i s r a i s e d a l i t t l e a n d about 3 g. of t h e s t a r t i n g m i x t u r e i s a d d e d u n t i l t h e e n t i r e m i x t u r e i s u s e d u p . W h e n t h e c r u c i b l e h a s c o o l e d down, t h e p r o d u c t i s c r u s h e d a n d s t o r e d in a c l o s e d c o n t a i n e r .
II. A s t o i c h i o m e t r i c m i x t u r e of a l u m i n u m p o w d e r a n d r e d s e l e n i u m i s p l a c e d in a c o m b u s t i o n t u b e , w h i c h i s e v a c u a t e d a n d s e a l e d off.
T h e end of t h e t u b e a t w h i c h t h e m i x t u r e i s s i t u a t e d i s c a r e f u l l y h e a t e d o v e r an open f l a m e u n t i l t h e o n s e t of t h e r e a c t i o n , w h i c h o c c u r s at t h e b e g i n n i n g of r e d h e a t . The r e a c t i o n p r o g r e s s e s slowly t h r o u g h o u t t h e e n t i r e m a s s and i s a c c o m p a n i e d by i n c a n d e s c e n c e .
III. A l u m i n u m t u r n i n g s a r e p l a c e d in a c a r b o n b o a t i n s e r t e d in a P y r e x r e a c t i o n t u b e . One end of t h e t u b e i s c o n n e c t e d t o a s o u r c e of high v a c u u m , t h e o t h e r end t o a s t o r a g e t u b e c o n t a i n i n g r e d s e l e n i u m . T h e s y s t e m i s e v a c u a t e d and t h e s e l e n i u m i s d r i v e n into t h e r e a c t i o n t u b e by h e a t i n g . T h e r e a c t i o n t u b e i t s e l f i s h e a t e d t o 600-650°C for 36 h o u r s , w h i c h i s t h e t i m e r e q u i r e d f o r c o m p l e t e c o n v e r s i o n .
PROPERTIES:
Yellow; s l o w l y h y d r o l y z e d in m o i s t a i r t o H2S e a n d A l ( O H )3.
