Crystal Structure of (NH 4 ) 2 [Mo 3 S(S 2 ) 6 ] Containing the Novel Isolated
Cluster [ M O 3 S 1 3 ] 2 _
A . Müller, S. P o h l , a n d M. D a r t m a n n
Fakultät für Chemie, Universität Bielefeld
J. P. Cohen and J. M.
Bennett
U n i o n Carbide Corporation, T a r r y t o w n , N . Y . 10591
R.M.
Kirchner
Chemistry D e p t . , Manhattan College, B r o n x , N . Y . 10471
Z. Naturforsch. 3 4 b , 4 3 4 - 4 3 6 (1979); received A u g u s t 2 8 / N o v e m b e r 10, 1978
Crystal Structure, M o l y b d e n u m , Sulfur, Cluster, M e t a l - M e t a l B o n d , Disulfide D i a t o m i c Ligands
T h e novel tri-nuclear metal-sulfur cluster [Mo 3 S(S 2 ) 6 ] 2 ~ can be obtained as its a m m o n i u m salt b y the reaction o f a M o i v containing aqueous solutions with polysulfide.
Its crystal and molecular structure has been determined b y a single crystal X - r a y study.
The crystals are monoclinic (space g r o u p C m , with a = 11.577(6) A , b = 16.448(7) Ä ,
c = 5.716(2) Ä , ß = 117.30(3)°, V = 967.2 A 3 , Z = 2, d e x p ti. = 2.54(2) g / c m 3 , d c a i =
2.54 g / c m 3 ) . T h e structure consists of isolated [ M o 3 S ( S 2 ) 6 ] 2 _ units, with three M o a t o m s
at the vertices of a triangle. There are bridging as well as terminal S 2 2 ~-ligands lying
a b o v e and below the Mo 3 -plane (bond distances: M o - M o = 2.722 A , Mo-S(terminal) =
2.435, M o - S ( b r i d g i n g ) = 2.452, M o 3 - S = 2.353(4) A and S - S = 2.04 A (mean values)).
Transition metal sulfur clusters are model combinary sulfur clusters were u n k n o w n until recently,
(NH4)2Mo3Si3
Calcd
Found
though
Crystal
pounds
of
bioinorganic
several halogen
interest
cluster
[1,
2].
Isolated
compounds
were
reported. W e were able to isolate the novel compound
(NH4)2[Mo3S(S2)6]
containing
w e l l as t e r m i n a l S 2 2 _ - l i g a n d s i n t h e
bridging
as
molybdenum-
s u l f u r - c l u s t e r a n i o n [2]. I n t h i s p a p e r t h e
crystal
s t r u c t u r e o f t h e c o m p o u n d is r e p o r t e d .
Experimental
Preparation
of (NHi)2[MozS(S2)e]
[2]
Method 1: T o a s o l u t i o n o f 2.00 g (0.011 m o l e w i t h
respect to molybdenum) of (NH4)6Mo7024 • 4 H 2 0 ,
1 . 5 0 g (0.022 m o l e ) o f N H 2 O H • H C l w a s a d d e d .
T h e mixture was stirred until a solution was obtained
a n d t h e n k e p t a t 4 0 - 5 0 °C f o r 5 m i n , w h e n a r e d brown solution containing some brownish y e l l o w
p r e c i p i t a t e w a s f o r m e d . A f t e r a d d i n g 30 m l o f
saturated a m m o n i u m polysulfide solution,
the
m i x t u r e w a s h e a t e d a t ca. 90 °C f o r 3 - 4 h . D a r k - r e d
c r y s t a l s s e p a r a t e d a n d w e r e filtered a n d w a s h e d
w i t h (NH 4 ) 2 Sa;, H 2 0 , e t h a n o l , C S 2 a n d d i e t h y l e t h e r .
Method 2: T o a 30 m l s o l u t i o n o f s a t u r a t e d
ammonium
polysulfide
1 g of solid
MoCl4py2
(PY = p y r i d i n e ) , w a s s l o w l y a d d e d w i t h c o n t i n u o u s
stirring. T h e reaction m i x t u r e w a s stirred for a n o t h e r
1 0 m i n , filtered f r o m a n y u n d i s s o l v e d p r e c i p i t a t e
a n d t h e filtrate k e p t i n a n o i l b a t h a t 90 °C f o r 1 - 2 h .
T h e precipitate w a s w a s h e d as described u n d e r
m e t h o d 1.
Requests for reprints should b e sent t o P r o f . Dr. A .
Müller, Fakultät für Chemie, Universität Bielefeld,
D-4800
Bielefeld.
0340-5087/79/0300-0434/$ 01.00/0
N 3.78
N 4.0
S 56.27,
S 55.8.
Data
X - r a y diffraction studies were carried out on A
S y n t e x P 2 i four-circle a u t o m a t e d diffractometer.
Crystals suitable for X - r a y analysis were obtained
b y the methods given above and m o u n t e d in glass
capillaries. Precession photographs confirmed t h a t
the crystals belonged to the monoclinic system a n d
that the space group was Cm. W i t h an experimental
d e n s i t y o f 2.54 g / c m 3 Z c o u l d o n l y b e 2. T h e
[Mo3Si3]2~-ion could o n l y posses a mirror p l a n e
t h o u g h t h e i d e a l s y m m e t r y s h o u l d be C 3 v . C r y s t a l
d a t a are s u m m a r i z e d in T a b l e I.
T a b l e I. S u m m a r y of crystal data of (NH 4 ) 2 [Mo 3 S(S 2 )6]Formula
Crystal system
Space g r o u p
a, b, c, ß [ A , d e g ]
V [A3], Z
dcaicd [ g / c m 3 ]
Data collection
(NH 4 ) 2 [Mo 3 S(S 2 )6]
monoclinic
Cm
11.577(6), 16.448(7), 5.716(2),
117.30(3)
967.2
2
2.54
and reduction
of the intensity
data
A s t a n d a r d r e f l e c t i o n w a s m e a s u r e d e v e r y 5 0 reflections a n d its intensity s h o w e d no significant fluct u a t i o n or evidence of decomposition of the crystal.
T h e processing of the d a t a w a s carried out as
d e s c r i b e d p r e v i o u s l y [3]. A n a b s o r p t i o n c o r r e c t i o n
was not applied (absorption coefficient [ c m - 1 ] : 31.8;
c r y s t a l d i m e n s i o n s [ m m ] : 0 . 1 2 X 0.04 X 0 . 0 3 ; r a d i a t i o n : M o - K a (X = 0 . 7 1 0 6 9 A ) ; s c a n s p e e d [deg. m i n " 1 ] :
2 . 0 - 2 9 . 3 (eo-20-scan m e t h o d ) ; b a c k g r o u n d / s c a n t i m e
ratio:
1 . 0 ; u n i q u e d a t a : 800; o b s e r v e d
data
(I > 1 . 9 6 a ( I ) ) : 7 6 6 ; sin 0 max //l [ A " 1 ] : 0.572).
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435
A. Müller et al. • Crystal Structure of (NH4)2[Mo3S(S2)6]
Table II. Positional and thermala parameters of (NH4)2[Mo3S(S2)6]Atom
Mol
Mo 2
SI
S2
S3
S4
S5
S6
S7
S8
S9
N
a
X
y
0.00000(0)
— 0.22875(21)
— 0.43002(73)
— 0.33884(74)
0.19059(92)
0.23196(85)
— 0.01298(56)
— 0.05912(53)
— 0.32151(64)
— 0.34444(61)
— 0.15169(79)
0.3518 (22)
0.00000(0)
0.08284(9)
0.00000(0)
0.00000(0)
0.00000(0)
0.00000(0)
0.15076(31)
0.10208(31)
0.18171(37)
0.20974(36)
0.00000(0)
0.1751 (13)
2
0.0000(0)
— 0.2118(42)
— 0.3765(15)
— 0.6007(14)
0.4261(17)
0.1146(19)
0.0168(11)
— 0.3418(10)
— 0.0375(13)
— 0.4107(12)
0.1661(14)
0.4193(43)
Atom
Bn
B22
b 33
Mo 1
Mo 2
SI
S2
S3
S4
S5
S6
S7
S8
S9
N
2.54(11)
2.60(7)
2.40(35)
2.27(31)
4.36(48)
2.59(38)
3.34(27)
2.94(25)
4.09(31)
3.61(30)
3.33(36)
5.62(134)
1.81(10)
1.89(6)
2.72(33)
3.13(34)
2.96(37)
3.48(39)
2.02(21)
2.32(20)
3.32(27)
2.73(24)
1.80(29)
3.95(105)
2.71(11)
0.00(0)
2.61(6)
0.09(7)
3.86(38)
0.00(0)
1.91(28)
0.00(0)
3.34(37)
0.00(0)
5.27(48)
0.00(0)
3.01(23) — 0.25(19)
2.75(21) — 0.30(19)
4.89(32)
0.46(23)
5.11(33)
0.56(22)
3.12(35)
0.00(0)
6.76(130)
0.82(96)
B12
B13
1.35(9)
1.46(5)
1.72(31)
0.84(26)
1.11(35)
1.67(35)
1.48(21)
1.62(20)
2.65(27)
2.03(27)
2.00(30)
2.87(108)
B23
0.00(0)
— 0.05(7)
0.00(0)
0.00(0)
0.00(0)
0.00(0)
— 0.35(19)
— 0.16(18)
— 0.73(24)
0.64(22)
0.00(0)
0.40(95)
In the form exp [1/4 (B n a* 2 A* 2 + - + 2 B12a*b*hk•••)].
Structure solution and refinement
T h e a t o m i c s c a t t e r i n g f a c t o r s for Mo(0), S(0), a n d
N ( 0 ) w e r e t a k e n f r o m t h e " I n t e r n a t i o n a l T a b l e s " [4].
A t h r e e - d i m e n s i o n a l P a t t e r s o n s y n t h e s i s [5] p r o v i d e d the location of the m o l y b d e n u m a t o m s in t h e
u n i t cell. D i f f e r e n c e F o u r i e r s y n t h e s e s i n d i c a t e d t h e
positions of the 13 sulfur a t o m s a n d led, a f t e r several
cycles of refinement, to the location of the nitrogen
atom.
T h e final refinement of the m o d e l c o n v e r g e d to
g i v e r e s i d u a l s R = 0 . 0 5 3 a n d Rw = 0 . 0 5 9 f o r t h e 7 6 6
o b s e r v e d r e f l e c t i o n s (see T a b l e I), u s i n g s t a t i s t i c a l
w e i g h t i n g a s d e s c r i b e d p r e v i o u s l y [3]
(highest
s h i f t / e r r o r ( f i n a l c y c l e ) : 0 . 0 1 ) . L i s t i n g s o f final v a l u e s
o f (Fc) a n d (F0) are a v a i l a b l e f r o m t h e a u t h o r s .
A t o m i c fractional coordinates are collected
in
Table II.
Results and Discussion
T h e c r y s t a l s t r u c t u r e consists o f discrete [M03S13]2units. T h e drawing in Fig. 1 illustrates the p a c k i n g
within the crystal. B o n d distances and angles
are
g i v e n in T a b l e I I I .
T h e c l u s t e r [ M 0 3 S 1 3 ] 2 - ( O R T E P d r a w i n g i n F i g . 2)
Table III. Bond distances (Ä) and angles (deg) for
[MO3S(S2)6]2- (estimated standard deviation in parentheses).
Mo
Mo
Mo
Mo
Mo
Mo
1-Mo 2
1-S 3
1-S 4
1-S 5
1-S 6
1-S 9
SI
-S2
S3 - S 4
S 5 -S 6
2.719(2)
2.423(9)
2.455(11)
2.489(5)
2.425(5)
2.348(10)
2.000(12)
2.045(14)
2.031(8)
Mo 2- M o l Mo 2'a 60.1(1
S 9 - Mo 1- S 3
95.7(3
S 9 - Mol- -S4
145.2(3
S 9 - Mo 1--S 5
85.1(2
S 9 -Mol- S 6
109.8(2
S3 - M o l - 5 4
49.6(3
S3 - M o l - •S 5
90.3(2
53 - M o l - S 6
126.9(2
54 - Mo 1- 55
93.9(2
54 - Mo 1- S 6
94.9(2
a
S 5 -Mol- -S5'
170.2(2
S 5 - Mol- S 6
48.8(2
S 5 - M o l - • S 6 ' a 136.2(2
S 6 -Mol- S 6 ' a
87.7(2
S 5 - Mo 2- •S 8
93.7(2
170.6(2
55 - Mo 2- S I
128.3(2
S 6 - Mo 2- -S 7
95.4(2
S 6 - Mo 2- -S 8
135.1(2
S 6 - Mo 2- - S I
50.6(2
S 7 - Mo 2- -S 8
90.5(2
S 7 - Mo 2- S I
94.2(2
S 8 - Mo2- • S I
Mo 1- S 9 - Mo 2 70.6(2
Mo2- •S 9 -Mo2' a 70.7(2
Mo 2- S 2 - Mo2' a 68.8(2
67.7(3
Mo2- -S 2 - SI
S 7 -S 8
Mo 2-Mo 2'a
Mo2-Sl
Mo 2-S 2
Mo 2-S 5
Mo 2-S 6
Mo 2-S 7
Mo 2-S 8
Mo 2-S 9
2.077(9
2.725(2
2.482(8
2.413(6
2.490(7
2.418(7
2.403(7
2.459(6
2.356(6
Mo 1- Mo 2- Mo2' a 59. 93(6)
S 9 - Mo 2- •S 2
109.6(3)
S 9 - Mo 2- S 5
84. 9(2
S 9 - Mo 2- S 6 109. 8(2
S 9 - Mo 2- •S7
93. 7(3
S 9 - Mo2- S 8 144. 3(3
S 9 - Mo 2- S I
85. 7(3
S 2 - Mo2- S 5 135. 7(2
S 2 - Mo2- S 6
87. 2(2
S 2 - Mo2- •S 7 128. 1(3
S 2 - Mo 2- •S 8
96. 2(2
S 2 - Mo 2- S I
48. 2(2
S5 - Mo 2- S 6
48. 9(2
S5 - Mo 2- -S 7
90. 6(2
Mo 1- S 3 - •S4
66. 0(3
M o l - •S4 - S 3
64. 4(3
Mo 1- S5 - Mo 2 66. 2(2
Mo 1- S5 - S 6
64. 0(2
Mo2- S 5 - S 6
63. 7(2
M o l - S 6 - Mo 2 68. 3(2
Mo 1- S 6 - S 5
67. 3(2
Mo 2- •S 6 -•S 5
67. 4(2
Mo2- S 7 -•S 8
66. 1(3
Mo 2- S 8 - •S 7
63. 3(3
Mo2- S I - Mo2' a 66 6(2
Mo2- S I - -S2
64 1(3
angles between the normal on the Mo3-plane(N) and
S2-ligands:
N-S1/S2:
28.1°
N-S3/S4:
12.1°
N-S5/S6:
12.0°
N-S7/S8:
0.8°
Fig. 1. ORTEP plot of the unit cell (without H-atoms).
a
Transformation x, y, z.
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A . Müller et al. • Crystal S t r u c t u r e o f (NH 4 ) 2 [Mo 3 S(S2)6]
436
possibility
of the preparation of the
homologous
cluster with n = 2 from a solution containing MoIV,
w h i c h w a s indeed possible. F r o m the above
tioned
cluster
F i g . 2. M o l e c u l a r s t r u c ture o f [ M O 3 S ( S 2 ) 6 ] 2 ( O R T E P p l o t , ellipss O . ' s8'oids with 5 0 % p r o b a bility).
scheme
the
existence
[Mo4mS4(S2)4]4~
of
could
the
also
men-
homologous
be
predicted.
T h e c e n t r a l u n i t {Mo 4 S 4 } c a n a l r e a d y b e f o u n d i n
[(C5Ha)MoS]4 [1] a n d in t h e solid state
structures
M [ M o 2 R e 2 ] S 8 a n d M ' M o 4 S 8 [8] ( M = F e , C o , N i , Z n ;
M'
=
Al,
Ga).
Obviously
the
stability
c o m p o u n d s is also c o n n e c t e d w i t h t h e
of
these
occurrence
has three m o l y b d e n u m atoms at the vertices of a
o f t r i - c o o r d i n a t e s u l f u r (for t h e l o w r e a c t i v i t y cf.
triangle
in the central units
with
a unique
S-atom above
its
center.
{Mov(S2)2Mov},
[1])
{Mo3IVS(S2)3}
T h e r e are bridging as w e l l as t e r m i n a l S22_-ligands,
and
{Mo4mS4}.
which
first
t w o u n i t s are also present in the solid state
both
lie a b o v e
and
below
the
Mo3-plane.
E a c h m o l y b d e n u m is c o o r d i n a t e d t o o n e
terminal
a n d t w o bridging S22--ligands as well as t w o other
the
s t r u c t u r e s o f |,[MO2(S2) 2 C1 4 C1 4 / 2 ] a n d
1 [ M O 3 S ( S 2 ) 3 C 1 2 C 1 4 / 2 ] [9].
A
m o l y b d e n u m atoms.
T h e d i r e c t e d s y n t h e s i s of c l u s t e r - c o m p o u n d s is a
I t is i n t e r e s t i n g t o n o t e t h a t
comparison
distances
are
shows
very
that
similar
corresponding
(Table IV)
even
bond
with
[6].
respect t o the a s y m m e t r i c coordination of the S 2 2 - -
F o r the transition elements Mo, W , T c and R e with
l i g a n d s (see T a b l e I I I a n d r e f . [7, 9]). T h e e x i s t e n c e
dw
of m e t a l - m e t a l bonds follows from the short distance
current p r o b l e m in transition m e t a l c h e m i s t r y
electron configurations, cluster t y p e s are e x p e c t e d
t o b e d u m b - b e l l s h a p e d (in t h e c a s e w h e r e n=
1),
a s w e l l as f r o m the d i a m a g n e t i s m of [Mo3S(S2)6]2"
t r i a n g u l a r (n = 2), t e t r a h e d r a l (n = 3) a n d o c t a h e d r a l
[10].
(n = 4) ( t h e r e f o r e n a l s o i n d i c a t e s t h e n u m b e r
[MO3IVS(S2)6]2- t h a n i n [ M o ^ ^ e ] 2 - as e x p e c t e d .
metal-metal
bonds
originating
from
each
of
metal
a t o m ) . R e c e n t l y , t h e first b i n a r y s p e c i e s w i t h n = 1
v i z [MO2(S2)6] 2 ~ [7] h a s b e e n i s o l a t e d i n t h e f o r m o f
its
ammonium
salt.
Therefore
we
expected
the
The
Mo-Mo
bond
distance
is
shorter
in
W e thank the Deutsche Forschungsgemeinschaft
and the F o n d s der Chemischen Industrie for
financial
support, Dr. Sarkar and Dr. R . G. B h a t t a c h a r y y a
for their experimental help and Dr. A . W . N a u m a n n
for initiating the cooporation.
T a b l e I V . C o m p a r i s o n o f b o n d distances o f c o m p o u n d s w i t h the central units {Mo 3 S(S2) 3 } a n d {Mo2(S2) 2 } (mean
values, in A ) .
[Mo3S(S2)6] 2
^[MO 3 S(S 2 ) 3 C1 2 C1 4 /2]
[MO 2 (S 2 )6] 2 i[Mo 2 (S 2 )2Cl 4 Cl 4 /2]
Mo-Mo
Mo-Sf
Mo-Sterme
2.722
2.745
2.827
2.833
2.353
2.36
2.435
-
-
2.459
-
M o - S b r i c Ige e
2.452
2.45
2.444
2.43
S-Sterm
2.06
-
2.049
-
S—Sbridge
2.02
2.03
2.043
1.980
a
b
c
d
a This w o r k , b ref. [9], c ref. [7], d ref. [9], e a v e r a g e distances ( t e r m : terminal S 2 - g r o u p s ; b r i d g e : bridging
S2-groups), f distance t o the S - a t o m a b o v e t h e M o 3 - p l a n e .
[1] H . V a h r e n k a m p , A n g e w . C h e m . 87, 363 ( 1 9 7 5 ) ;
A n g e w . C h e m . I n t . E d . E n g l . 14, 322 (1975).
[2] A . Müller, S. Sarkar, R . G . B h a t t a c h a r y y a , S.
P o h l , a n d M . D a r t m a n n , A n g e w . Chem. 90, 564
( 1 9 7 8 ) ; A n g e w . Chem. I n t . E d . E n g l . 17, 535
(1978). A l t e r n a t i v e p r e p a r a t i o n : C. R . K u r t a k a n d
L . D . H a r t z o g , U . S . P a t e n t s 3764649 a n d 3876755
(the c o r r e c t s t o i c h i o m e t r y w a s n o t g i v e n , there).
[3] S. P o h l a n d B . K r e b s , C h e m . B e r . 108, 2934 (1975).
[4] " I n t e r n a t i o n a l T a b l e s f o r X - R a y
Crystallog r a p h y " , V o l . I V , K y n o c h Press, B i r m i n g h a m
1974.
[5] All calculations were d o n e using t h e " S y n t e x X T L
P r o g r a m S y s t e m " a n d the p r o g r a m O R T E P f r o m
C. K . J o h n s o n .
[6] R . B . K i n g , P r o g . I n o r g . C h e m . 15, 287 (1972).
[7] A . Müller, W . O. N o l t e , a n d B . K r e b s , A n g e w .
C h e m . 90, 286 (1978); A n g e w . Chem. I n t . E d .
E n g l . 17, 279 (1978); J . A m . Chem. Soc., t o b e
submitted.
[8] C. P e r r i n , R . Chevrel, and M. Sergent, J . Solid
State C h e m . 19, 305 ( 1 9 7 6 ) ; C. Perrin, R . Chevrel.
a n d M . Sergent, C. R . A c a d . Sei. Ser. C. 280, 949
(1975).
[9] J . M a r c o l l , A . R a b e n a u , D . M o o t z , and H . W u n derlich, R e v . Chim. Min. 11, 607 (1974).
[10] T h e interpretation o f t h e t h e r m o c h e m i c a l , m a g n e t i c a n d s p e c t r o s c o p i c properties ( U V , V I S ,
X P S , I R , R A M A N , X a - c a l c u l a t i o n s ) will be
p u b l i s h e d later.
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Download Date | 6/17/17 5:40 AM