1 Recent Advances in Actinide and Lanthanide Chemistry K. W . BAGNALL Chemistry Division,
The
A.E.R.E.,
chemistry
americium,
of
the
all being
series.
Their
within
are
cal similarities
In the
All
behave
in much
of the of the
and compared
from
+4,
shows
thorium
to
quantities,
is
or higher oxidation both
as an inner horizontal
states, transition
similarities
group and to a lesser degree, some
with
ments.
actinides
in substantial
best considered
chemistry
the actinide
chemistry
lighter available
now well understood. these elements
H a r w e l l , Didcot, Berks., E n g l a n d
the group actinides
the
with
in their
same way
actinides
verti
4, 5, and 6 d-transition +3
as the
is reviewed
the corresponding
ele
oxidation
states
lanthanides. within
this
The context
lanthanides.
Τ η r e v i e w i n g the c h e m i s t r y of the a c t i n i d e s as a g r o u p , t h e simplest A
a p p r o a c h is to consider e a c h v a l e n c e state separately. I n t h e t e r v a l e n t
state, a n d s u c h examples of the d i v a l e n t state as are k n o w n , the a c t i n i d e s s h o w s i m i l a r c h e m i c a l b e h a v i o r to the l a n t h a n i d e s . E x p e r i m e n t a l diffi culties w i t h the t e r p o s i t i v e a c t i n i d e s u p to p l u t o n i u m are
considerable
because of the r e a d y o x i d a t i o n of this state. S o m e c o r r e l a t i o n exists w i t h the a c t i n i d e s i n studies of the l a n t h a n i d e tetrafluorides a n d plexes.
F o r other c o m p o u n d s
fluoro
com
of the 4-valent a c t i n i d e s , p r o t a c t i n i u m
shows almost as m a n y s i m i l a r i t i e s as differences
between thorium and
the u r a n i u m - a m e r i c i u m set; thus i n v e s t i g a t i n g the c o m p l e x f o r m i n g p r o p erties of t h e i r h a l i d e s has a t t r a c t e d attention.
I n the 5- a n d 6-valent
states, the elements f r o m u r a n i u m to a m e r i c i u m s h o w a degree of c h e m i c a l s i m i l a r i t y .
Protactinium ( V )
considerable
behaves i n m u c h t h e
same w a y as these elements i n the 5-valent state except f o r w a t e r , w h e r e its h y d r o l y t i c b e h a v i o r is m o r e r e m i n i s c e n t of n i o b i u m a n d t a n t a l u m . T h i s r e v i e w is l a r g e l y r e s t r i c t e d to w o r k w h i c h has b e e n p u b l i s h e d i n t h e 1960's w i t h emphasis o n the c h e m i s t r y of t h e h a l i d e s a n d t h e i r complexes.
T h e s e h a v e b e e n the subject of most of the recent research, 1
2
LANTHANIDE /ACTINIDE
CHEMISTRY
a n d a c o m p l e t e c o m p a r i s o n of a l l the k n o w n c h e m i s t r y of the l a n t h a n i d e s a n d actinides has not b e e n a t t e m p t e d p r e v i o u s l y .
Divalent State Compounds
of
d i v a l e n t s a m a r i u m , e u r o p i u m , a n d y t t e r b i u m are
w e l l - k n o w n . I n recent years, l o w e r h a l i d e s of other l a n t h a n i d e s , s u c h as neodymium
praseodymium
(48),
(45,
49, 90),
a n d t h u l i u m (4)
have
b e e n o b t a i n e d b y r e d u c i n g the t r i h a l i d e w i t h the m e t a l . T h e c o r r e s p o n d i n g r e a c t i o n of t h o r i u m t e t r a i o d i d e w i t h t h o r i u m m e t a l has l e d to the i d e n t i f i c a t i o n of t w o c r y s t a l l i n e forms of T h l
2
(41, 91);
i t is u n l i k e l y t h a t
the T h , or e v e n T h , i o n is present i n T h l , b u t l i k e P r l , w h i c h is 2 +
3 +
2
f o r m u l a t e d as P r ( I ~ ) ( e ~ ) (2), 3+
Th
4 +
(r) (2e~) 2
2
2
the c o m p o u n d is p r o b a b l y of the t y p e
C e r t a i n l y one c r y s t a l f o r m is d i a m a g n e t i c
(41).
(41),
suggesting the latter f o r m u l a t i o n . I n a d d i t i o n , a l l of the l a n t h a n i d e s h a v e n o w b e e n o b t a i n e d i n the d i v a l e n t state i n d i l u t e s o l u t i o n i n a C a F fused
salt electrolysis
(52),
2
m a t r i x b y γ-irradiation
or a l k a l i n e e a r t h m e t a l r e d u c t i o n
(74), (68).
A t t e m p t s to r e d u c e a m e r i c i u m , the a n a l o g of e u r o p i u m , to this l o w e r o x i d a t i o n state h a v e also b e e n successful u n d e r s i m i l a r c o n d i t i o n s the A m
2 +
ion, w h i c h occupies C a
its E S R s p e c t r u m . unsuccessful
2 +
(51);
sites i n the c r y s t a l , w a s i d e n t i f i e d b y
S i m i l a r attempts to o b t a i n u r a n i u m ( I I )
have been
(51).
Tervalent State I n the l a n t h a n i d e s , the b a s i c c h e m i s t r y of p r o m e t h i u m has b e c o m e better k n o w n because of the a v a i l a b i l i t y of r e l a t i v e l y large q u a n t i t i e s of 1 4 7
P m (103),
the o b s e r v e d b e h a v i o r of the element b e i n g m u c h as one
w o u l d expect. Thl
4
I n the a c t i n i d e s , T h l
w i t h t h o r i u m m e t a l (41, 91)
3
has b e e n p r e p a r e d b y r e a c t i o n of
a n d appears to b e a n i o n i c c o m p o u n d ;
if so, i t w i l l p r e s u m a b l y b e p a r a m a g n e t i c .
W i t h the h i g h e r a c t i n i d e s
b e i n g p r o d u c e d i n large q u a n t i t i e s , it is p l e a s i n g to see c r y s t a l l o g r a p h i c d a t a r e p o r t e d for c a l i f o r n i u m c o m p o u n d s , the e m e r a l d green t r i c h l o r i d e b e i n g h e x a g o n a l ( U C 1 ) , a n d the sesquioxide m o n o c l i n i c ( S m 0 ) 3
2
w h i l e , w i t h the i d e n t i f i c a t i o n of a l o n g e r - l i v e d (79 fermium [
2 5 7
F m (60)]
days)
3
isotope
(58) of
it appears as t h o u g h m i c r o c h e m i c a l studies of a l l
the actinides u p to element 100 w i l l b e c o m e p r a c t i c a b l e . Studies of the c o m p l e x c h e m i s t r y of the t e r v a l e n t l a n t h a n i d e s s h o w that c o o r d i n a t i o n n u m b e r s h i g h e r t h a n six are c o m m o n , for e x a m p l e i n the tetrakistropolonates (79),
the complexes
d i m e t h y l a c e t a m i d e ( D M A ) (77)
of the perchlorates w i t h
or o c t a m e t h y l p y r o p h o s p h o r a m i d e
of the i o d i d e s w i t h Ν,Ν-dimethylformamide ( D M F ) w i t h triphenylphosphine (or
arsine)
oxide
(46),
(76),
a n d the
N,N(61),
the nitrates β-diketone
1.
BAGNALL
chelates (28);
Recent
Advances
m a n y of these complexes are d i s c u s s e d later i n this v o l u m e .
A c t i n i d e ( I I I ) analogs d o not seem to h a v e b e e n p r e p a r e d . I n t h e i r h a l o complexes, the l a n t h a n i d e s ( I I I )
a n d actinides
(III)
s h o w a c o n s i d e r a b l e s i m i l a r i t y . T h u s tetrafluorolanthanides ( I I I ) a n d -actinides ( I I )
(65,
72)
(100)
h a v e b e e n r e p o r t e d , a l l of t h e m h a v i n g
hexagonal symmetry, and hexahalolanthanides (III)
a n d some a c t i n i d e
( I I I ) analogs h a v e also b e e n p r e p a r e d ; the t r i p h e n y l p h o s p h o n i u m h e x a chlorolanthanides (III)
have been isolated from nonaqueous
solvents,
a n d t h e i r v i s i b l e spectra h a v e b e e n d i s c u s s e d i n some d e t a i l (62, T h e corresponding americium (III)
89).
salt c a n b e m a d e i n a s i m i l a r m a n -
ner ( 8 7 ) , b u t the aqueous a l k a l i c h l o r i d e / A m C l system is m o r e c o m p l i 3
c a t e d , the species C s A m C l
4
· 4 H 0 and C s N a A m C l 2
2
6
b e i n g isolated from
aqueous s o l u t i o n a n d " C s A m C l " f r o m e t h a n o l i c h y d r o c h l o r i c a c i d s o l u 3
6
tions of the c o m p o n e n t s ( 2 5 ) ; this last m a y , h o w e v e r , b e C s A m C l i . 8
plutonium compound, C s P u C l 3
h y d r o c h l o r i c a c i d (95).
6
3
7
The
· 2 H 0 , has b e e n i s o l a t e d f r o m aqueous 2
M a n y more lanthanide and actinide halo complex
species h a v e b e e n r e p o r t e d for f u s e d salt m e l t s , r a n g i n g i n the case of the c h l o r i d e s f r o m the s i m p l e M C L f i o n to M C 1 " a n d M C l i 2
9
3
3
0
a
" ; some
examples are s h o w n i n T a b l e I. M a n y of t h e m exist o n l y i n f u s e d salts a n d h a v e not b e e n p r e p a r e d b y other means. Table I.
Anionic Chlorocomplexes in Fused Salts
Anion
Metal
MCLf MC1 MCV" MC1 " M C1 5
9
2
2
6
7
M CVM C1 2
3
1 0
Reference
(M)
9 9, 72, 78, 80, 97, 98 9, 59, 69, 72, 78, 80, 97, 98 72 72, 80 9, 59 9, 69
La L a , Ce, Pr, N d , Sm, Pu Se, Y , L a , C e , P r , N d , S m , Y b , P u Pu Sm, P u Se, C e , P r , N d Y, L a , Ce
Tetravalent State I n the 4-valent state of the elements, one of the most r e m a r k a b l e p r e p a r a t i v e reactions r e p o r t e d r e c e n t l y is the i s o l a t i o n of P r F sodium
fluoride
f r o m the c o m p l e x N a P r F 2
presence of fluorine (92).
6
4
by washing
w i t h a n h y d r o u s H F i n the
T h e structures of P r F
4
a n d its fluoro complexes
are analogous to those of the c o r r e s p o n d i n g u r a n i u m c o m p o u n d s a n d e v i d e n c e has b e e n o b t a i n e d for the f o r m a t i o n of P r ( I V ) species i n the r e a c t i o n of P r O n or P r 0 6
A v a r i e t y of
fluoro
complexes
formed
2
w i t h dinitrogen pentoxide
(93).
b y t h e 4-valent elements
from
p r o t a c t i n i u m to c u r i u m h a v e also b e e n r e p o r t e d r e c e n t l y A n u n u s u a l l a y e r s t r u c t u r e has b e e n f o u n d for T h l existence
of
PaCl
4
has n o w
been
(I),
nitrato
confirmed.
4
PaOCl , 2
(82). (104), PaOBr
a n d the 2
(31),
4
LANTHANIDE/ACTINIDE
PaBr
4
PaOI , and P a l
(33),
2
CHEMISTRY
(31 ) a n d some of t h e i r complexes, i n c l u d i n g
4
h e x a c h l o r o - , h e x a b r o m o - , a n d h e x a i o d o p r o t a c t i n a t e s ( I V ) (33) prepared. P a B r
have been
appears to b e i s o s t r u c t u r a l w i t h one f o r m of T h B r
4
4
and
n o t w i t h m o n o c l i n i c U B r . H e x a c h l o r o complexes of a l l the a c t i n i d e s ( I V ) 4
f r o m t h o r i u m to p l u t o n i u m are n o w o n r e c o r d , o n l y ( N E t ) T h C l 4
2
6
being
r e p o r t e d as d i m o r p h i c . A l l the analogous h e x a b r o m o complexes are also k n o w n since the n e p t u n i u m ( I V ) a n d p l u t o n i u m ( I V ) c o m p o u n d s b e e n i s o l a t e d f r o m e t h a n o l i c h y d r o b r o m i c a c i d (88). thorium ( I V ) , and uranium ( I V )
(37),
h e x a i o d o complexes
(16)
have
Protactinium ( I V ) are
m o r e difficult to o b t a i n , i n a c c o r d a n c e w i t h the m a r k e d C h a t t - A h r l a n d Α-class b e h a v i o r of b o t h l a n t h a n i d e s a n d a c t i n i d e s , b u t h a v e b e e n m a d e b y r e a c t i o n of the t e t r a i o d i d e s w i t h the a p p r o p r i a t e c a t i o n i o d i d e i n m e t h y l c y a n i d e s o l u t i o n , the t e t r a p h e n y l - [ T h ( I V ) , U ( I V ) ] phenylmethylarsonium [Pa ( I V ) ]
and tri-
salts b e i n g the most stable h e x a i o d o
compounds. A l t h o u g h p l u t o n i u m t e t r a c h l o r i d e is u n k n o w n , its complexes oxygen
donor
Cs PuCl
6
2
l i g a n d s , s u c h as a m i d e s , c a n b e
with
prepared b y treating
w i t h a s o l u t i o n of the l i g a n d i n a n o n a q u e o u s solvent
(22);
some of t h e complexes f o r m e d b y the a c t i n i d e t e t r a c h l o r i d e s w i t h a m i d e s are s h o w n i n T a b l e I I . T h e Ν,Ν-dimethylaeetamide ( D M A )
complexes
a p p e a r to b e c h l o r i n e - b r i d g e d d i m e r s i n w h i c h the m e t a l e x h i b i t s 8coordination
whereas
(17),
complex T h C l
4
*4 D M A
n e p t u n i u m (70)
t h o r i u m forms
the
simple
T h e t h o r i u m (19),
(19).
8-coordinate
u r a n i u m (26),
and
t e t r a n i t r a t e complexes w i t h D M A , 2 M ( N G ) · 5 D M A , 3
4
are p r o b a b l y n i t r a t e - b r i d g e d d i m e r s analogous to the U C 1 c o m p l e x , b u t 4
the t h o r i u m a n d u r a n i u m t e t r a t h i o c y a n a t e complexes w i t h D M A (11, are 1:4 m o n o m e r s a n d are 8-coordinate l i k e the o c t a i s o t h i o c y a n a t o plexes
U n f o r t u n a t e l y , these t e t r a c h l o r i d e — D M A complexes
(75).
19) com de
c o m p o s e i n a n x - r a y b e a m , a n d e v i d e n c e for t h e i r structures has b e e n obtained
by
indirect chemical methods
a n d is therefore
somewhat
speculative. Table II. MC1 MC1 2MC1 MC1 4
· 6CH CONH · 4CH CONH(CH ) · 5CH CON(CH ) · 4CH CON(CH ) 3
4
4
Actinide Tetrachloride-Acetamide 2
3
4
3
3
3
3
2
M = = M = M = M
3
2
Complexes
U , N p , P u (22) U (19) U , N p , P u (22) T h (19)
U n u s u a l coordination numbers have been
r e p o r t e d for d i m e t h y l
sulfoxide ( D M S O ) a n d hexamethylphosphoramide ( H M P A )
complexes
of some a c t i n i d e t e t r a h a l i d e s , n o t a b l y 7 - c o o r d i n a t i o n i n U C 1 · 3 D M S O 4
and T h B r
4
· 3 H M P A , a n d 9-coordination i n T h C l
a p p e a r to b e m o n o m e r i c (18).
4
Interestingly, T h B r
b e h a v e as a 1:1 electrolyte i n n i t r o m e t h a n e (18),
· 5 D M S O , a l l of w h i c h 4
* 6 D M S O appears to so that t h o r i u m m a y
1.
BAGNALL
Recent
5
Advances
w e l l b e 9-coordinate i n this c o m p l e x also. S o m e i n f r a r e d d a t a are s h o w n i n T a b l e I I I . C o m p l e x e s of t h e tetrahalides w i t h m e t h y l e n e b i s s u l f o x i d e s ( 5 0 ) , p h o s p h i n e oxides
( 5 5 ) a n d w i t h d i c a r b o x y l i c a c i d amides
(14)
h a v e also b e e n p r e p a r e d , b u t a l l a p p e a r to b e p o l y m e r i c a n d eis-chelates d o n o t seem to b e f o r m e d . Table III.
MX
4
^S = 0,
S = 0, cm.'
1
ThCl UC1 ThBr UBr
4
4
4
4
· 5DMSO · 3DMSO · 6DMSO · 6DMSO
4
4
4 4 4
· 2HMPA · 2HMPA · 3HMPA · 2HMPA · 2HMPA
cm:
1
108 103 102 112
942 947 948 938 P = 0,
ThCl ThBr ThBr UC1 UBr
(18)
Complexes with Oxygen Donors
Δνρ
cm:
1
o,
=
cm:
1
159 174 130 167 184
1042 1027 1071 1034 1017
Pentavalent State C o n s i d e r a b l e advances h a v e b e e n m a d e i n o u r k n o w l e d g e
of t h e
5-valent a c t i n i d e s , a g a i n m a i n l y i n t h e h a l i d e s a n d h a l o complexes. is n o w k n o w n , m a d e f r o m N p 0
*H
3
2
m e t a l w i t h m o l t e n l i t h i u m p e r c h l o r a t e (43). the most a t t e n t i o n , t h e p e n t a f l u o r i d e (94), bromide
a n d pentaiodide
(34)
oxygen
donors
(38),
5
P r o t a c t i n i u m has r e c e i v e d
as w e l l as t h e i r complexes a l l having been
i n v e s t i g a t e d i n t h e past f e w years. U n l i k e N b C l b r i d g e d p o l y m e r (47),
2
p e n t a c h l o r i d e (10, 36), p e n t a -
a n d t h e i r h a l o complexes,
chlorine-bridged dimers, P a C l
Np 0
0 (23) o r b y r e a c t i o n of n e p t u n i u m
5
with
thoroughly
a n d U C 1 , w h i c h are 5
appears to b e a n infinite l i n e a r c h l o r i n e -
5
its s y m m e t r y b e i n g a p p r o x i m a t e l y
O . 5h
T h e o x y h a l i d e s of t h e 5-valent a c t i n i d e s h a v e p r o v e d to b e of c o n s i d e r a b l e interest, o x y g e n Pa OCl 2
(36),
8
b r i d g e d species
analogous to U O F 2
8
s u c h as P a O F 2
being reported.
(67)
spectra of t h e r a n g e of o x y g e n - b r i d g e d p r o t a c t i n i u m ( V ) (36)
8
and
(94)
T h e infrared oxychlorides
suggest that these represent successive stages i n t h e c h l o r i n a t i o n
of t h e p o l y m e r i c p e n t o x i d e ( F i g u r e 1 ) . T h e other k n o w n p r o t a c t i n i u m (V)
oxyhalides—PaOBr , PaOI , 3
nature (34),
Pa0 Br, 2
a n d P a 0 I — a r e similar i n 2
3
a n d U 0 B r (73)—which
m a y also b e p o l y m e r s .
2
Hydrated N p O F fluoride
3
b u t there are n o d a t a f o r t h e u r a n i u m a n a l o g — U O B r ( 8 5 )
3
(12)
has b e e n p r e p a r e d b y t h e a c t i o n of h y d r o g e n
o n the recently reported pentoxide, N p 0 2
5
(23, 43),
but N p F
5
itself has n o t y e t b e e n r e c o r d e d . Salts of t h e fluoro c o m p l e x ions M F " , M F 6
r e p o r t e d f o r P a ( V ) (5,7,
7
2
" , and M F
8
3
" have been
29, 30, 40, 66), U ( V ) (6, 56, 57, 81, 83, 84, 86,
6
LANTHANIDE/ACTINIDE
Pa O Cl
PaOClo
2
\
CI
CI
0< Pa
Pa
/
/ CI
\
CI
Pa OCl 2
Figure 1. 96), N p ( V )
\
CI
8
Pa (V)
and P u ( V )
(3)
oxygenated neptunium ( V )
4
CI
CI CI
s
CHEMISTRY
Oxychlorides
( δ ) , the last t w o b e i n g t h e first n o n -
and plutonium ( V )
compounds.
the p r e p a r a t i v e p r o c e d u r e s u s e d for u r a n i u m ( V )
fluoro
Some
complexes
of are
shown in Table I V . A recent s t u d y of the a l k a l i m e t a l / u r a n i u m fluoride c o m p l e x systems has s h o w n that K U F o , K U F , a n d K U F : i
3
7
a
c r y s t a l s y m m e t r y b e i n g unaffected b y the structure of K P a F 2
7
8
are i s o m o r p h o u s fluoride
(99),
i o n absences.
the The
has b e e n d e t e r m i n e d o n l y r e c e n t l y ( 3 9 ) , a n d it has
b e e n s h o w n that each p r o t a c t i n i u m a t o m is s u r r o u n d e d b y n i n e
fluorine
atoms i n w h a t is effectively a t r i g o n a l p r i s m w i t h three a d d e d e q u a t o r i a l fluorine
atoms; the P a F
fluorine
bridges.
groups are l i n k e d i n infinite chains b y
9
Salts of t h e analogous p r o t a c t i n i u m ( V ) ( 1 0 ) a n d u r a n i u m ( V )
two (20)
c h l o r o c o m p l e x ions, M C 1 " a n d M C 1 ~ , h a v e b e e n o b t a i n e d f r o m t h i o n y l 0
8
3
1.
BAGNALL
Recent
7
Advances
c h l o r i d e solutions of the 5-valent elements, b u t no h e p t a c h l o r o
complexes
h a v e b e e n i s o l a t e d . S i m i l a r l y , so f a r o n l y the h e x a b r o m o - a n d h e x a i o d o protactinates ( V )
have been obtained, prepared from methyl cyanide
solutions of the c o m p o n e n t s
(38).
C e s i u m h e x a c h l o r o u r a n a t e (V) has b e e n u s e d to p r e p a r e U C 1 * R P O 5
3
complexes b y r e a c t i o n w i t h the l i g a n d i n m e t h y l e n e d i c h l o r i d e (21), r e a c t i o n analogous to that u s e d to p r e p a r e P u C l corresponding P a C l
complexes,
4
complexes h a v e also b e e n m a d e (32);
5
d a t a are g i v e n i n T a b l e V . W h e r e a s N b C l of the l i g a n d , f o r m i n g N b O C l
some i n f r a r e d
· P h P O reacts w i t h a n excess
5
3
· 2 P h P O , the P a C l
3
a
a n d the
3
d o not. O n the other h a n d , n e i t h e r the N b C l
5
and U C 1
5
5
complexes
n o r PaCl» complexes w i t h
h e x a m e t h y l p h o s p h o r a m i d e ( H M P A ) react w i t h a n excess of l i g a n d . A l k a l i m e t a l dioxofluorides of the t y p e A M 0 F I
a n d A m (2, 64)
c o m p l e x salts of n e p t u n i u m ( V ) Table IV. MiUF
(M =
2
and americium ( V )
(24)
Np, Pu
(64)
( 2 5 ) are n o w
Preparation of U r a n i u m ( V ) Fluoro Complexes M = (a) N O , N 0 1
6
2
h a v e b e e n p r e p a r e d f r o m aqueous s o l u t i o n a n d c h l o r o
+
2
(b, c) L i , N a , K , R b , C s
+
+
+
+
+
+
(a) N O + U F - » N O U F (57) N O F + U F -> N O U F (57) 6
6
5
6
in 10-27M H F (b) ΜΨ + U F >MiUF 5
6
(6)
300°e. (c) ΜΨ 4- U F M iUF 2
M = K , Rb\ Cs 1
7
2ΜΨ + U F M iUF 3
5
+
300°C. >%MnJF +
3ΜΨ + U F
5
Na UF
2
3
Table V .
+
7
+
+ y M njF
NbCl, · Ph PO TaCl · Ph PO PaCl · Ph PO UC1 · Ph PO NbOCl · 2Ph PO 3
5
3
5
3
3
3
2
3
350°C. > M *UF 2
7
+
3
2
8
(84)
8
390°C. >Na UF 3
(86)
8
Infrared D a t a for M C l · P h P O Complexes 5
Ρ = 0,
3
e
350°C. >M !UF
+ y F
(83)
6
+
M i = Na , K , Rb , Cs
8
5
>MiUF
5
977 987 990 973 1167
cm:
1
3
AvP = O, 215 205 202 219 25
cm:
1
Reference 32 32 32 21 32, 44
8
LANTHANIDE/ACTINIDE
k n o w n ; the f o r m e r are salts of the " N p 0 0 2
f o r m a t i o n of C s N p O C l 2
i o n is m o r e
4
3
" and N p O C l
5
2
CHEMISTRY
" ions.
The
f r o m aqueous s o l u t i o n i n d i c a t e s that t h e N p 0
5
easily c h l o r i n a t e d t h a n h a d b e e n
suspected,
2
+
but further
c h l o r i n a t i o n results o n l y i n d i s p r o p o r t i o n a t i o n . " C s A m 0 0 " is isostruc3
t u r a l w i t h the n e p t u n i u m ( V ) c o m p o u n d
2
4
a n d there is some d o u b t
(25),
as to w h e t h e r these c o m p o u n d s are m o n o m e r i c or m o r e c o r r e c t l y f o r m u l a t e d as C s ( M 0 ) C l i i . 8
2
3
A f e w d e r i v a t i v e s of oxyanions h a v e also b e e n p r e p a r e d ;
protac-
t i n i u m ( V ) forms h e x a n i t r a t o complexes, P a ( N 0 ) ~ , b y r e a c t i o n of the 3
6
h e x a c h l o r o c o m p l e x w i t h d i n i t r o g e n p e n t o x i d e , i n contrast to n i o b i u m a n d tantalum w h i c h , under similar conditions, y i e l d only tetranitrato complexes, M O ( N 0 ) " ( 3 5 ) . 3
NpO(N0 ) 3
3
Neptunium (V)
4
h a v e also b e e n r e p o r t e d (71).
a n d selenato
complex
acids, H P a O ( S 0 ) 3
4
nitrates, N p 0 N 0 2
Protactinium ( V ) 3
and
3
sulfato-
and H P a O ( S e 0 ) , 3
4
have
3
b e e n o b t a i n e d f r o m aqueous s o l u t i o n ( 1 3 ) , b u t n o f u l l y s u l f a t e d or selen a t e d species h a v e b e e n r e c o r d e d .
Hexavalent State M u c h less w o r k has b e e n r e p o r t e d for the 6-valent elements as c o m p a r e d w i t h the v o l u m e of l i t e r a t u r e for the a c t i n i d e s i n l o w e r states. Np0
3
valence
H y d r a t e d n e p t u n i u m a n d p l u t o n i u m trioxides are n o w k n o w n , * H 0 and P u 0 2
3
·· ( 0 . 8 ) H O b e i n g r e a d i l y o b t a i n e d b y the a c t i o n 2
of o z o n e o n a n aqueous suspension of n e p t u n i u m ( V ) or p l u t o n i u m ( I V ) h y d r o x i d e s at 90 ° C . (23); at 18°C.
(23)
Np0
3
· 2 H 0 is o b t a i n e d i n a s i m i l a r m a n n e r 2
or b y o z o n e o x i d a t i o n of n e p t u n i u m ( V )
l i t h i u m - p o t a s s i u m n i t r a t e eutectic at 1 5 0 ° C .
i n a molten
(42).
A n o t h e r u n s u c c e s s f u l a t t e m p t has b e e n m a d e to p r e p a r e A m F , 6
fluorinating
Am 0 2
s u c h as N a U F 2
8
3
(63),
i n the presence of P t F NH UF 4
7
6
and N O U F
(102)
C o m p l e x e s of
(100). 7
(56)
by UF«
are n o w k n o w n ,
b u t the c o m p l e x i n g b e h a v i o r of n e p t u n i u m a n d p l u t o n i u m hexafluorides a n d u r a n i u m h e x a c h l o r i d e has scarcely b e e n i n v e s t i g a t e d . T h e most stable f o r m of the actinides ( V I ) M0
2
2 +
is the o x y g e n a t e d
ion
, a n d this t y p e of species has r e c e i v e d m u c h a t t e n t i o n .
A l t h o u g h a m e r i c i u m ( V I ) is r a p i d l y r e d u c e d to a m e r i c i u m ( I I I ) b y c h l o r i d e i o n i n aqueous s o l u t i o n , the i n s o l u b l e r e d C s A m 0 C l 2
o b t a i n e d w h e n the a m e r i c i u m ( V )
2
4
is r e a d i l y
c h l o r o c o m p l e x is t r e a t e d w i t h c o n -
c e n t r a t e d h y d r o c h l o r i c a c i d ; the m e c h a n i s m of the r e a c t i o n is not yet k n o w n , b u t i t is not a result of d i s p r o p o r t i o n a t i o n Anhydrous neptunyl s o d i u m n e p t u n y l acetate Np0
3
fluoride, (52),
(25).
previously obtained b y
fluorinating
is m o r e c o n v e n i e n t l y m a d e b y t r e a t i n g
* H 0 w i t h l i q u i d b r o m i n e t r i f l u o r i d e at r o o m t e m p e r a t u r e , h y d r o 2
g e n fluoride at 3 0 0 ° C , or fluorine at 2 3 0 ° C , a n d e v e n b y v a c u u m d r y i n g a h y d r o f l u o r i c a c i d s o l u t i o n of N p 0
3
· H 0 (12), 2
f r o m w h i c h it appears
1.
BAGNALL
9
Recent Advances
that t h e n e p t u n y l c o m p o u n d is less s t r o n g l y h y d r a t e d t h a n u r a n y l
fluoride.
C o m p l e x e s of u r a n y l c h l o r i d e w i t h a v a r i e t y of o x y g e n d o n o r l i g a n d s c o n t i n u e to b e r e p o r t e d , n o t a b l y w i t h p h o s p h i n e oxides ( 5 5 ) , p y r i d i n e N - o x i d e s (27),
N , N - d i m e t h y l f o r m a m i d e (71),
acetamide ( 1 5 ) , a n d w i t h
the Ν,Ν,Ν',Ν'-tetramethyldiearboxylic a c i d a m i d e s (14),
t h e last b e i n g
m a i n l y p o l y m e r i c c o m p o u n d s . A f e w s i m i l a r c o m p l e x e s of u r a n y l b r o m i d e ( 54 ) a n d i o d i d e ( 71 ) are also k n o w n . I n c o n c l u s i o n , c o m p a r e d w i t h t h e ( i - t r a n s i t i o n elements a n d t h e l a n t h a n i d e s , l i t t l e i n f o r m a t i o n is a v a i l a b l e o n t h e m a g n e t i c a n d s p e c t r a l properties of t h e a c t i n i d e s as a g r o u p , so t h a t there is c o n s i d e r a b l e scope f o r f u r t h e r w o r k i n this area. T h e s y m m e t r y properties o f / - o r b i t a l s are scarcely m e n t i o n e d i n t h e textbooks, a n d one m u s t search to find a n y t r e a t m e n t of t h e m i n t h e l i t e r a t u r e . T h i s reflects t h e c o m p l e x m a g n e t i c b e h a v i o r of m a n y a p p a r e n t l y m a g n e t i c a l l y d i l u t e a c t i n i d e complexes, together w i t h t h e o b v i o u s c o m p l e x i t y of t h e i r spectra, p a r t i c u l a r l y of species of h i g h c o o r d i n a t i o n n u m b e r a n d u n k n o w n , b u t p r o b a b l y l o w , symmetry.
I n this c o n n e c t i o n there is a n o b v i o u s n e e d f o r m o r e s t r u c
t u r a l w o r k , f o r i n n e a r l y e v e r y case c r y s t a l l o g r a p h i c d a t a are l a c k i n g a n d structures h a v e b e e n i n f e r r e d b y i n d i r e c t m e t h o d s .
Literature Cited (1) Asprey, L. B., Coleman, J. S., Reisfeld, M. J., ADVAN. CHEM. SER. 71, 122 (1967). (2) Asprey, L. B., Ellinger, F. H., Zachariasen, W. H., J. Am. Chem. Soc. 76, 5235 (1954). (3) Asprey, L. B., Keenan, T. K., Penneman, R. Α., Sturgeon, G. D., Inorg. Nucl. Chem. Letters 2, 19 (1966). (4) Asprey, L. B., Kruse, F. H.,J.Inorg. Nucl. Chem. 13, 32 (1960). (5) Asprey, L. B., Kruse, F. H., Penneman, R. Α.,J.Am. Chem. Soc. 87, 3518 (1965). (6) Asprey, L. B., Penneman, R. Α., Inorg. Chem. 3, 727 (1964). (7) Asprey, L. B., Penneman, R. Α., Science 145, 924 (1964). (8) Asprey, L. B., Sturgeon, G. D., Penneman, R. Α., J. Am. Chem. Soc. 87, 5803 (1965). (9) Baev, A. K., Novikov, G. I., Zh. Neorgan. Khim. 6, 2610 (1961). (10) Bagnall, K. W., Brown, D., J. Chem. Soc. 1964, 3021. (11) Bagnall, K. W., Brown, D., Colton, R., J. Chem. Soc. 1964, 2527. (12) Bagnall, K. W., Brown, D., Easey, J. F., J. Chem. Soc. (to be pub lished). (13) Bagnall, K. W., Brown, D., Jones, P. J.,J.Chem. Soc. 1965, 176. (14) Bagnall, K. W., Brown, D., Jones, P. J.,J.Chem. Soc. 1966, 741. (15) Bagnall, K. W., Brown, D., Jones, P. J.,J.Chem. Soc. (to be published). (16) Bagnall, K. W., Brown, D., Jones, P. J., du Preez, J. G. H., J. Chem. Soc. 1965, 350. (17) Bagnall, K. W., Brown, D., Jones, P. J., du Preez, J. G. H., J. Chem. Soc. 1965, 3594. (18) Bagnall, K. W., Brown, D., Jones, P. J., du Preez, J. G. H., J. Chem. Soc. 1966, 737. (19) Bagnall, K. W., Brown, D., Jones, P. J., Robinson, P. S., J. Chem. Soc. 1964, 2531.
10
LANTHANIDE/ACTINIDE CHEMISTRY
(20) Bagnall, K. W., Brown, D., du Preez, J. G. H., J. Chem. Soc. 1964, 2603. (21) Bagnall, K. W., Brown, D., du Preez, J. G. H., J. Chem. Soc. 1965, 5217. (22) Bagnall, K. W., Deane, A. M., Markin, T. L., Robinson, P. S., Stewart, Μ. Α. Α., J. Chem. Soc. 1961, 1611. (23) Bagnall, K. W., Laidler, J. B., J. Chem. Soc. 1964, 2693. (24) Bagnall, K. W., Laidler, J. B., J. Chem. Soc. 1966, 516. (25) Bagnall, K. W., Laidler, J. B., Stewart, M. A. A. (to be published). (26) Bagnall, K. W., Robinson, P. S., Stewart, Μ. Α. Α.,J.Chem. Soc. 1961, 4060. (27) Balakrishnan, P. V., Patil, S. K., Venkatasetty, Η. V., J. Inorg. Nucl. Chem. 28, 537 (1966). (28) Bauer, H., Blanc, J., Ross, D. L., J. Am. Chem. Soc. 86, 5125 (1964). (29) Brown, D., Easey, J. F., Nature 205, 589 (1965). (30) Brown, D., Easey, J. F., J. Chem. Soc. 1966, 254. (31) Brown, D., Easey, J. F., Jones, P. J., J. Chem. Soc. (to be published). (32) Brown, D., Easey, J. F., du Preez, J. G. H., J. Chem. Soc. 1966, 258. (33) Brown, D., Jones, P. J., Chem. Commun. 1966, 280. (34) Brown, D., Jones, P. J., J. Chem. Soc. 1966, 262. (35) Brown, D., Jones, P. J., J. Chem. Soc. 1966, 733. (36) Brown, D., Jones, P. J., J. Chem. Soc. 1966, 874. (37) Brown, D., Jones, P. J., J. Chem. Soc. (to to published). (38) Brown, D., Jones, P. J., private communication. (39) Brown, D., Smith, A. J., Chem. Commun. 1965, 554. (40) Bukhsh, M. N., Flegenheimer, J., Hall, F. M., Maddock, A. G., Miranda, C. Ferreira de, J. Inorg. Nucl. Chem. 28, 421 (1966). (41) Clark, R. J., Corbett, J. D., Inorg. Chem. 2, 460 (1963). (42) Cohen, D., Inorg. Chem. 2, 866 (1963). (43) Cohen, D., Walter, A. J., J. Chem. Soc. 1964, 2696. (44) Copley, D. B., Fairbrother, F., Thompson, Α., J. Less-Common Metals 8, 256 (1965). (45) Corbett, J. D., Druding, L. F., Burkhard, W. J., Lindahl, C. B., Discus sions Faraday Soc. 32, 79 (1961). (46) Cousins, D., Hart, Α., J. Inorg. Nucl. Chem., in press. (47) Dodge, R. P., Smith, G. S., Johnson, Q., Elson, R. W., U.S. Report UCRL-14581 (1966). (48) Druding, L. F., Corbett, J. D., J. Am. Chem. Soc. 83, 2462 (1961). (49) Druding, L. F., Corbett, J. D., Ramsey, Β. N., Inorg. Chem. 2, 869 (1963). (50) Du Preez, J. G. H., private communication. (51) Edelstein, N., Easley, W., McLaughlin, R., J. Chem. Phys. 44, 3130 (1966). (52) Fong, F. K., J. Chem. Phys. 41, 2291 (1964). (53) Fried, S., Nat. Nucl. Energy Ser., Div. IV, 14 A, 471 (1954). (54) Gans, P., Ph.D. Thesis, London (1964). (55) Gans, P., Smith, B. C., J. Chem. Soc. 1964, 4172. (56) Geichman, J. R., Smith, Ε. Α., Ogle, P. R., Inorg. Chem. 2, 1012 (1963). (57) Geichman, J. R., Smith, Ε. Α., Trond, S. S., Ogle, P. R., Inorg. Chem. 1, 661 (1962). (58) Green, J. L., U.S. Report UCRL-16516 (1965). (59) Gut, R., Gruen, D. M., J. Inorg. Nucl. Chem. 21, 259 (1961). (60) Hulet, Ε. K., Hoff, R. W., Evans, J. E., Lougheed, R. W., Phys. Rev. Letters 13, 343 (1964).
1. BAGNALL
Recent Advances
11
(61) Joesten, M . D., Jacob, R. Α., ADVAN. CHEM. SER. 71, 13 (1967). (62) Jørgensen, C. K., Proc. Conf. Rare Earth Res., 5th, Ames, Iowa, 1965, Paper No. CERI-TIC-P99. (63) Katz, S., Inorg. Chem. 3, 1598 (1964). (64) Keenan, T. K., Inorg. Chem. 4, 1500 (1965). (65) Keller, C., Schmutz, Η., Z. Naturforsch. 19B, 1080 (1964). (66) Keller, O. L., Chetham-Strode, Α., Proc. Colloque Phys.-chim. Protactinium1965,119 (67) Kirslis, S. S., McMillan, T. S., Bernhardt, Η. Α., U.S. Report K-567 (1950). (68) Kiss, Z. J., Yocom, P. N.,J.Chem. Phys. 41, 1511 (1964). (69) Korshunov, B. G., Drobot, D. V., Zh. Neorgan. Khim. 9, 222 (1964). (70) Laidler, J. B.,J.Chem. Soc. 1966, 780. (71) Lamisse, M., Heimburger, R., Rohmer, R., Compt. rend. 258, 2078 (1964). (72) Leary, J. Α., U.S. Report LA-2661 (1962). (73) Levet, J. C., Compt. rend. 260, 4775 (1965). (74) McClure, D. S., Kiss, Z., J. Chem. Phys. 39, 3251 (1963). (75) Markov, V. P., Traggeim, Ε. N., Zh. Neorgan. Khim. 6, 2316 (1961). (76) Moeller, T., Galasyn, V., J. Inorg. Nucl. Chem. 12, 259 (1960). (77) Moeller, T., Vicentini, G., J. Inorg. Nucl. Chem. 27, 1477 (1965). (78) Morozov, I. S., Ionov, V. I., Korshunov, B. G., Zh. Neorgan. Khim. 4, 1457 (1959). (79) Muetterties, E. L., Wright, C. M.,J.Am. Chem. Soc. 87, 4706 (1965). (80) Novikov, G. I., Polyachenok, O. G., Frid, S. Α., Zh. Neorgan. Khim. 9, 472 (1964). (81) Penneman, R. Α., Asprey, L. B., Sturgeon, G., J. Am. Chem. Soc. 84, 4608 (1962). (82) Penneman, R. Α., Keenan, T. K., Asprey, L. B., ADVAN. CHEM. SER. 71, 248 (1967). (83) Penneman, R. Α., Kruse, F. H., George, R. S., Coleman, J. S., Inorg. Chem. 3, 309 (1964). (84) Penneman, R. Α., Sturgeon, G. D., Asprey, L. B., Inorg. Chem. 3, 126 (1964). (85) Prigent, J., Ann. Chim. (Paris), 15, 65 (1960). (86) Rüdorff, W., Leutner, H., Ann. 632, 1 (1960). (87) Ryan, J. L., ADVAN. CHEM. SER. 71, 331 (1967). (88) Ryan, J. L., Jørgensen, C. K., Mol. Phys. 7, 17 (1963). (89) Ryan, J. L., Jørgensen, C. K., Cyanamid European Research Institute, Geneva, Rep. CERI-TIC-P95 (1965). (90) Sallach, R. Α., Corbett, J. D., Inorg. Chem. 2, 457 (1963). (91) Scaife, D. E., Wylie, A. W., J. Chem. Soc. 1964, 5450. (92) Soriano, J., Givon, M., Shamir, J., Inorg. Nucl. Chem. Letters 2, 13 (1966). (93) Soriano, J., Marcus, Y., Inorg. Chem. 3, 901 (1964). (94) Stein, L., Inorg. Chem. 3, 995 (1964). (95) Stevens, R. E., J. Inorg. Nucl. Chem. 27, 1873 (1965). (96) Sturgeon, G. D., Penneman, R. Α., Kruse, F. H., Asprey, L. B., Inorg. Chem. 4, 748 (1965). (97) Sun, I. C., Morozov, I. S., Zh. Neorgan. Khim. 3, 1914 (1958). (98) Sung, Yu-Lin, Novikov, G. I., Zh. Neorgan. Khim. 8, 700 (1963). (99) Thoma, R. E., Friedman, Η. Α., Penneman, R. Α., J. Am. Chem. Soc. 88, 2046 (1966). (100) Thoma, R. E., Insley, H., Hebert, G. M., Inorg. Chem. 5, 1222 (1966). (101) Tsujimura, S., Cohen, D., Chernick, C. L., Weinstock, B., J. Inorg. Nucl. Chem. 25, 226 (1963).
12
LANTHANIDE/ACTINIDE CHEMISTRY
(102) Volavsek, B., Croat. Chem. Acta. 33, 181 (1961). (103) Weigel, F., Proc. Conf. Rare Earth Res., 5th, Ames, Iowa, 1965, Paper No. 650804-7 (Nucl Sci. Abstr. 19, 43988 (1965) ). (104) Zalkin, Α., Forrester, J. D., Templeton, D. H., Inorg. Chem. 3, 639 (1964). RECEIVED August 7, 1966.
