Reactions and properties of the dinuclear molybdenum complex [(η5-C5H3)2(CMe 2)(SiMe2)]Mo2(CO)6

Article abstract of DOI:10.1016/j.poly.2012.04.045

Reactions of the title complex (1), which features the rigid doubly-bridged biscyclopentadienyl ligand and the unusually long Mo-Mo bond in the structure, with a variety of classic substrates are explored. Complex 1 reacts with I ₂ in CH₂Cl₂ to give the expected Mo-Mo cleaved product [(η⁵-C₅H₃)₂(CMe ₂)(SiMe₂)]Mo₂(CO)₆I₂ (2A) with a Mo-Mo distance of 5.329 A?. While the same reaction in benzene forms the product 2B, which has the same structural formula as 2A but a different conformation, in which the Mo-Mo distance is 6.442 A?. Reaction of 1 with Ph₂E₂ (E = S, Se) in refluxing toluene or under UV irradiation yields products with the carbonyls completely removed, [(η⁵-C₅H₃)₂(CMe ₂)(SiMe₂)]Mo₂(EPh)₂(μ-EPh) ₂ (3a-b). Reaction of 1 with [Et₂NC(S)S]₂ results in the di-substituted product [(η⁵-C₅H ₃)₂(CMe₂)(SiMe₂)]Mo ₂(CO)₄(Et₂NC(S)S)₂ (4). Reaction of 1 with C₂Ph₂ affords the acetylene-bridged derivative [(η⁵-C₅H₃)₂(CMe ₂)(SiMe₂)]Mo₂(CO)₄(μ-C ₂Ph₂) (5). Reaction of 1 with an excess of PPh₃ in refluxing toluene only provides the mono-substituted derivative [(η⁵-C₅H₃)₂(CMe ₂)(SiMe₂)]Mo₂(CO)₅(PPh₃) (6), while the reaction of 1 with excess P(OPh)₃ under the same conditions produces not only the mono-substituted derivative [(η⁵-C₅H₃)₂(CMe ₂)(SiMe₂)]Mo₂(CO)₅(P(OPh) ₃) (7), but also the di-substituted derivative [(η⁵- C₅H₃)₂(CMe₂)(SiMe ₂)]Mo₂(CO)₄(P(OPh)₃)₂ (8). The reactivity and properties of the doubly-bridged molybdenum complex 1 and the corresponding non-bridged and singly-bridged analogs are compared. The molecular structures of 2A, 2B, 3a, 5 and 8 have been determined by single crystal X-ray diffraction.

Full text of DOI:10.1016/j.poly.2012.04.045

Polyhedron 42 (2012) 57–65
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Polyhedron
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Reactions and properties of the dinuclear molybdenum complex
[(g
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)6
b
b
b,
Bo-Lin Zhu a, , Shan-Sheng Xu , Xiu-Zhong Zhou , Bai-Quan Wang
⇑
⇑
a College of Chemistry and Tianjin Key Laboratory of Structure and Performance for Functional Molecules, Tianjin Normal University, Tianjin 300387, People’s Republic of China
b College of Chemistry, Nankai University, Tianjin 300071, People’s Republic of China
a r t i c l e i n f o
a b s t r a c t
Article history:
Reactions of the title complex (1), which features the rigid doubly-bridged biscyclopentadienyl ligand
Received 18 April 2012
Accepted 30 April 2012
Available online 18 May 2012
and the unusually long Mo–Mo bond in the structure, with a variety of classic substrates are explored.
Complex 1 reacts with I2 in CH2Cl2 to give the expected Mo–Mo cleaved product [(g
5-C5H3)2(CMe2)(Si-
Me2)]Mo2(CO)6I2 (2A) with a Mo–Mo distance of 5.329 Å. While the same reaction in benzene forms
the product 2B, which has the same structural formula as 2A but a different conformation, in which
the Mo–Mo distance is 6.442 Å. Reaction of 1 with Ph2E2 (E = S, Se) in refluxing toluene or under UV irra-
Keywords:
Mo–Mo bond
Photolysis
Ph2E2
Doubly-bridged biscyclopentadienyl ligand
X-ray diffraction
diation yields products with the carbonyls completely removed, [(
-EPh)2 (3a–b). Reaction of 1 with [Et2NC(S)S]2 results in the di-substituted product [(
(SiMe2)]Mo2(CO)4(Et2NC(S)S)2 (4). Reaction of 1 with C2Ph2 affords the acetylene-bridged derivative [(g5
C5H3)2(CMe2)(SiMe2)]Mo2(CO)4( -C2Ph2) (5). Reaction of 1 with an excess of PPh3 in refluxing toluene
only provides the mono-substituted derivative [(
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)5(PPh3) (6), while the
reaction of 1 with excess P(OPh)3 under the same conditions produces not only the mono-substituted
derivative [(
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)5(P(OPh)3) (7), but also the di-substituted derivative [(g5
g
5-C5H3)2(CMe2)(SiMe2)]Mo2(EPh)2
5-C5H3)2(CMe2)
(l
g
-
l
g
g
-
C5H3)2(CMe2)(SiMe2)]Mo2(CO)4(P(OPh)3)2 (8). The reactivity and properties of the doubly-bridged molyb-
denum complex 1 and the corresponding non-bridged and singly-bridged analogs are compared. The
molecular structures of 2A, 2B, 3a, 5 and 8 have been determined by single crystal X-ray diffraction.
Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction
doubly-bridged biscyclopentadienyl ligand and the significantly
long Mo–Mo bond [3.433(1) Å] in the structure, was chosen as a
The doubly-bridged biscyclopentadienyl ligands [(g5
C5H3)2(X)(Y)] (X, Y = CH, CH2, CH2CH2, CMe2, SiMe2, SiMe2SiMe2,
GeMe2 or SnMe2), especially [(
5-C5H4)2(SiMe2)2], have been
extensively explored as frameworks for dinuclear transition metal
complexes. Two metal atoms are locked on either the same or
opposite sides of the rigid ligand and then maintained in close
proximity. This feature in a structure results in cooperative effects
between the two metals, as well as unique properties in reactivity
and as catalysts for doubly-bridged biscyclopentadienyl dinuclear
metal complexes [1–10]. We recently reported the reactions of
-
representative compound to study the reactivity of this type of
complex. Related research has been partly explored by Wang’s
group, which is mostly concentrated on the reactions of 1 with ni-
trile, diazoalkane, carbon disulfide, carboxylate-substituted allenes
and phosphanylalkynes [11–14]. It is well-known that non-bridged
and singly-bridged biscyclopentadienyl dinuclear analogs readily
react with a variety of classic substrates, like halogens [6,15–17],
Ph2E2 (E = S or Se) [18–22], [Et2NC(S)S]2 [23–25], RC„CR [26–30]
or PR3 [31] to give the corresponding products via oxidative addi-
tion or CO substitution. To develop a deeper understanding of the
reactivity of 1 and to make a comparison with the corresponding
non- or singly-bridged analogs, in this paper we have explored
the reactions of 1 with the same substrates mentioned above.
g
a
certain type of doubly-bridged biscyclopentadienyl ligand,
(C5H4(CMe2))(C5H4(EMe2)) (E = Si or Ge) with M(CO)6 (M = Mo or
W), which produced the corresponding dinuclear complex [(g5
-
C5H3)2(CMe2)(EMe2)]M2(CO)6 containing an elongated M–M bond
(type A in Fig. 1), and/or a structurally novel complex with
2. Results and discussion
an M–E bond (type B in Fig. 1) [9]. One of the products, [(g5
-
2.1. Reaction of [(
CH2Cl2
g
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)6 (1) with I2 in
C5H3)2(CMe2)(SiMe2)]Mo2(CO)6 (1), which features the rigid
⇑
Corresponding authors. Fax: +86 2 3766532.
E-mail addresses: bolinzhu@yahoo.com.cn (B.-L. Zhu), bqwang@nankai.edu.cn
A solution of complex 1 and 1 equiv of I2 in CH2Cl2 was stirred
for 6 h at room temperature, and the reaction afforded complex 2A
(B.-Q. Wang).
0277-5387/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.poly.2012.04.045

58
B.-L. Zhu et al. / Polyhedron 42 (2012) 57–65
Me2
C
Me2
C
bridges (CMe2 and SiMe2), and each Mo atom has a ‘‘four-legged
piano stool’’ coordination, where the four legs are three CO groups
and an iodine atom. The two Mo(CO)3I units are both coordinated
M
Me2
E = Si, or Ge
M = Mo, or W
(CO)3
E
to the exo side of the slightly bended [(g
5-C5H3)2(CMe2)(SiMe2)] li-
M
M
M
EMe2
(CO)3 (CO)3
(CO)3
gand, and the two iodine atoms are oriented towards different
A
B
directions in a trans way. A similar arrangement of halogen atoms
has been presented in the respective singly-bridged analog [(g5
-
Fig. 1. Type A and B compounds.
C5H4)2(SiMe2)]Mo2(CO)6Cl2 [16]. The bend of the doubly-bridged
ligands, reflected by the angle (19.8°) between the planes of two
Cp rings, is relatively small, which is consistent with the Mo–Mo
non-bonding distance of 5.328 Å. The cyclopentadienyl rings of
the bridging ligand are slightly twisted with respect to each other,
which is evident in the small torsion angle \Cp(centroid)–Mo(1)–
Mo(2)–Cp(centroid) (4.9°).
Me2
C
Me2
Me2
C
I2
Me2
Si
Si
CH2Cl2
Mo
Mo
Mo
Mo
I
OC
CO OC
(CO)3 (CO)3
I
CO
OC CO
1
2A
2.2. Reaction of 1 with I2 in benzene
Scheme 1. Reaction of 1 with I2 in CH2Cl2.
The halogen-bridged cationic complexes [Cp2Ru2(CO)4(l
-X)]+
can be isolated from aromatic solvents as intermediates from the
reactions of Cp2Ru2(CO)4 and excess halogens (X2) [31]; an attempt
here was made to extend this reaction scope to the molybdenum
analog. The reaction of 1 with excess I2 in benzene was carried
out, and the product 2B was isolated as a red air-stable solid
(Scheme 2). The IR spectrum (solid state, KBr) of 2B exhibits the ex-
(Scheme 1), which was isolated as a dark-red air-stable crystal. The
IR spectrum (solid state, KBr) shows the expected strong absorp-
tions between 2034 and 1938 cmꢀ1 for terminal carbonyls. The
1H NMR spectrum of 2A displays two peaks at 5.70 (4H) and 5.47
(2H) ppm for all the protons in the two cyclopentadienyl rings,
indicating its symmetrical structure. In addition, it shows two sing-
lets at 1.68, and 1.57 ppm for the CMe2 protons, and two singlets at
0.77 and 0.43 ppm for the SiMe2 protons. Upon further confirma-
tion by single crystal X-ray diffraction, the molecular structure of
pected strong m
(CO) bands in the region 1946–2050 cmꢀ1. The 1H
NMR spectrum shows two peaks at 5.75 (4H) and 5.49 (2H) ppm
for the protons in the cyclopentadienyl rings, two singlets at 1.72
and 1.60 ppm for the CMe2 protons, and two singlets at 0.81 and
0.47 ppm for the SiMe2 protons. All these spectroscopic data for
2B are very close to those for 2A. The exact molecular structure
of 2B was eventually confirmed by single crystal X-ray diffraction,
which showed it was not the expected iodine-bridged product, but
a compound with the same structural formula as 2A, but with a dif-
ferent conformation.
The molecular structure of 2B is presented in Fig. 3. It has a
crystallographic symmetry plane passing though the bridged car-
bon, the silicon atoms and the center of the Mo–Mo line. There
are two noteworthy differences between 2A and 2B. The first is
the significant bending of the doubly-bridged ligand, which is re-
flected by a much smaller dihedral angle (114.9°) between the
2A is assigned as [(g
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)6I2. Complexes
containing a similar structure have been reported from the reac-
tions of the corresponding dimeric Cp02M2(CO)6 (M = Mo, W) com-
plexes, including the non- [15], single- [16] and double-bridged [6]
biscyclopentadienyl and fulvalene [17] dinuclear metal analogs
with halogens. These results show that complex 1 has consistent
reactivity towards I2 to the respective non- or singly-bridged biscy-
clopentadienyl analogs.
The molecular structure of 2A is presented in Fig. 2, and it has
an approximate C2 axis passing through the center of the Si(1)–
C(19) line and the center of the Mo(1)–Mo(2) line. The molecule
consists of two [(g
5-C5H3)Mo(CO)3I] moieties linked by two
Fig. 2. ORTEP diagram of [(g
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)6I2 (2A). Thermal ellipsoids are shown at the 30% level. Hydrogens are omitted for clarity. Selected bond lengths [Å]
and angles [°] are as follows: C(8)–C(19) 1.542(7), C(13)–C(19) 1.559(7), Si(1)–C(7) 1.835(6), Si(1)–C(12) 1.820(6), Mo(1)–I(1) 2.8561(10), Mo(2)–I(2) 2.8586(11), Mo(1)–C(1)
2.005(11), Mo(1)–C(2) 1.975(10), Mo(1)–C(3) 1.979(10), Mo(1)–Cp(centroid) 2.001, Mo(2)–Cp(centroid) 1.997, \C(7)–Si(1)–C(12) 99.4(4), \C(8)–C(19)–C(13) 114.9(6),
\Cp(centroid)–Mo(1)–Mo(2)–Cp(centroid) 4.9, \Cp–Cp fold angle, 160.2.

B.-L. Zhu et al. / Polyhedron 42 (2012) 57–65
59
Me2
C
Me2
C
Me2
C
Me2
excess I2
C6H6
Me2
Me2
Si
Si
Si
Ph2E2/toluene
OC Mo
Mo CO
1
Mo Mo
OC
CO
Mo
Mo
hν or
OC
I
CO
(CO)3 (CO)3
PhE
EPh
I
E
E
Ph Ph
1
2B
3a (E = S)
3b (E = Se)
Scheme 2. Reaction of 1 with I2 in C6H6.
Scheme 3. Reaction of 1 with Ph2E2.
two Cp planes, compared to that (160.2°) in 2A. Both Mo(CO)3I
units are also coordinated to the exo side of the severely bent li-
gand, which results in a very long Mo–Mo non-bonding distance
of 6.442 Å. It is interesting to note that some intermolecular
Mo–Mo distances in 2B (the minimum value is 5.974 Å) are even
shorter than the intramolecular distance. The second is the
arrangement of two iodine atoms in the structure, which are ori-
ented towards the same directions in cis way, and located on the
CMe2-bridge side. The carbonyl ligands on each Mo atom adopt a
perfectly eclipsed conformation, so avoidance of non-bonding
interactions between the carbonyls might be another factor that
results in the super long intramolecular Mo–Mo distance. These
structural features of 2B are highly similar to those in the reported
display no
m(CO) absorption, indicating that all the carbonyl li-
gands are completely removed from the Mo atoms. The 1H NMR
spectra of 3a and 3b show three peaks in the range d 5.50–
4.30 ppm for the protons in each cyclopentadienyl ring, consistent
with an ABC spin system. Additionally they show two singlet peaks
(0.90 and 0.60 ppm for 3a; 0.92 and 0.53 ppm for 3b) for the differ-
ent CH3 protons in the SiMe2 group, and two singlet peaks (2.12
and 1.53 ppm for 3a; 2.15 and 1.41 ppm for 3b) for the different
CH3 protons in the CMe2 group. It is worth mentioning that the sig-
nal for the CMe2 protons (2.12 ppm in 3a; 2.15 ppm in 3b) obvi-
ously shifts to low field with respect to the typical C(CH3)2
region, and this most likely results from the deshielding effect of
a phenyl ring nearby. Upon further confirmation by single crystal
X-ray diffraction, the molecular structure of 3a is assigned as
doubly-bridged analog [(
A, \Cp–Cp = 120° and
tances = 6.542(1) Å) [5].
g
5-C5H3)2(SiMe2)2]Mo2(CO)6Cl2 (Molecule
intramolecular Mo–Mo dis-
[(g l-SPh)2, the formation of
5-C5H3)2(CMe2)(SiMe2)]Mo2(SPh)2(
According to the above-mentioned analytical results, a com-
pound with the same structure formula can form different config-
urations on crystallization, which is an interesting finding. These
data reveal that the doubly-bridged biscyclopentadienyl ligand
which is through the oxidative addition of the S–S bond of Ph2S2
to complex 1 and CO loss. The non-bridged analog [CpMo(SPh)2]x
has been isolated from a similar reaction of [CpMo(CO)3]2 with
Ph2S2 [20,21], however, due to poor solubility in organic solvents,
the detailed structure of [CpMo(SPh)2]x has not yet been deter-
mined. Fortunately, complex 3a is remarkably soluble in polar sol-
vents, like dichloromethane. The CMe2 and SiMe2 substituents on
the Cp rings are very likely responsible for the enhanced solubility.
Therefore, an X-ray quality crystal of 3a was obtained from a mix-
ture of dichloromethane and hexane, and the complete structural
determination for this type of binuclear complex is presented for
the first time (Fig. 4).
[(g
5-C5H3)2(CMe2)(SiMe2)] is actually flexible; it can bend at an
appropriate angle to accommodate the different configurations of
the products. Many effects can easily modify the bending of dou-
bly-bridged ligands, such as the interaction between the coordina-
tion spheres of the metal atoms, or the crystal packing. In our case,
it seems that the solvents lead to different configurations; how-
ever, a detailed investigation on the exact cause and possible ex-
change between them is the subject of further efforts.
The molecular structure of 3a has an approximate C2 axis pass-
ing through the center of the Si(1)–C(11) line and the center of the
2.3. Reaction of 1 with Ph2E2 (E = S, Se)
Mo(1)–Mo(2) line. The two Mo atoms are
g
5-coordinated to the
corresponding cyclopentadienyl rings of the doubly-bridged [(g5
-
The reactions of 1 with Ph2E2 (E = S, Se) in refluxing toluene or
under UV irradiation produce complexes 3a–b, which were iso-
lated as air-stable blue crystals, although the yields are much high-
er under photochemical conditions (Scheme 3). Their IR spectra
C5H3)2(CMe2)(SiMe2)] ligand, and they are also symmetrically
bridged by two SPh groups (with a syn arrangement of the phenyl
groups), and bonded by two terminal SPh groups with two phenyl
Fig. 3. ORTEP diagram of [(g
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)6I2 (2B). Thermal ellipsoids are shown at the 30% level. Hydrogens are omitted for clarity. Selected bond lengths [Å]
and angles [°] are as follows: C(5)–C(9) 1.540(5), Si(1)–C(4) 1.861(4), Mo(1)–I(1) 2.847(1), Mo(1)–C(1) 2.012(6), Mo(1)–C(2) 1.978(5), Mo(1)–C(3) 2.003(5), Mo(1)–
Cp(centroid) 2.009, \C(5)–C(9)–C(5A) 107.6(5), \C(4)–Si(1)–C(4A) 96.2(3), \Cp–Cp fold angle, 114.9.

60
B.-L. Zhu et al. / Polyhedron 42 (2012) 57–65
Fig. 4. ORTEP diagram of [(
g
5-C5H3)2(CMe2)(SiMe2)]Mo2(SPh)2(
l
-SPh)2 (3a). Thermal ellipsoids are shown at the 30% level. Hydrogens are omitted for clarity. Selected bond
lengths [Å] and angles [°] are as follows: Mo(1)–Mo(2) 2.482(1), Mo(1)–S(1) 2.452(2), Mo(1)–S(2) 2.442(2), Mo(1)–S(3) 2.412(9), Si(1)–C(2) 1.832(5), Si(1)–C(7) 1.834(5),
Mo(1)–Cp(centroid) 2.038, Mo(2)–Cp(centroid) 2.034, \C(2)–Si(1)–C(7) 93.6(3), \C(1)–C(11)–C(6) 106.3(4), \Mo(1)–S(1)–Mo(2) 61.18(6), \Mo(1)–S(2)–Mo(2) 124.6(2),
\Mo(1)–S(3)–C(28) 109.6(2), \Mo(2)–S(4)–C(34) 109.8(2), \Mo(2)–Mo(1)–S(3) 125.36(7), \S(1)–Mo(1)–S(2) 106.84(6), \S(3)–Mo(1)–Mo(2)–S(4) ꢀ21.8(1), \Cp(centroid)–
Mo(1)–Mo(2)–Cp(centroid) 4.9, \Cp–Cp fold angle, 127.6.
groups extending outside in a sterically favorable way. One compa-
rable structure would be that of the non-bridged biscyclopentadie-
nyl analog [(
groups coordinate to two Mo atoms in a bridging mode. Another
structural analog is the compound [( -SMe)2]2
5-C5H5)MoCl(
g l-SMe)2]2 [32], in which all four SMe
5-C5H5)Mo(
Me2
C
Me2
g
l
Si
[Et2NC(S)S]2
toluene
[33], in which two Mo atoms are coordinated by two bridging
SMe groups and two terminal chloro ligands. The most notable fea-
ture among all structural parameters in 3a is its extremely short
Mo–Mo bond distance (2.482(1) Å). It is significantly shorter than
1
(CO)2Mo
Mo(CO)2
S
S
S
S
C
C
NEt2
NEt2
that (2.603(2) Å) in [(g l-SMe)2]2 [32], in which the
5-C5H5)Mo(
4
Mo–Mo bond is already very short, but still considered as a single
bond, while it is in good agreement with the Mo–Mo bond dis-
tances in compounds like Cp2Mo2(CO)4 (2.448(1) Å) [34] and
Scheme 4. Reaction of 1 with [Et2NC(S)S]2.
[(g l-SMe)2]2 (2.4507(2) Å) [33], in which the Mo–
5-C5H5)MoCl(
Mo bonds are assigned as triple bonds. Considering that the Mo–
Mo bond distance in 3a is much closer to those for typical Mo„Mo
bonds, it is more reasonable to assign it as a triple bond, which also
makes complex 3a meet the 18-electron rule requirement. Besides,
the short Mo„Mo bond results in not only severe bending of the
2.4. Reaction of 1 with [Et2NC(S)S]2
Complex 1 reacted with [Et2NC(S)S]2 in refluxing toluene to give
compound 4 (Scheme 4), which was isolated as an air-stable red
solid. The 1H NMR spectrum of 4 exhibits one multiplet at d 5.1–
5.7 ppm for the protons in the Cp rings, one broad multiplet at d
3.64 ppm for the CH2 protons in the Et group, and one sharp triplet
at d 1.16 ppm for the CH3 protons in the Et group. The IR spectrum
doubly-bridged [(g
5-C5H3)2(CMe2)(SiMe2)] ligand, which is re-
flected by a smaller dihedral angle (127.6°) between the two cyclo-
pentadienyl rings than that in complex 1 (149.3°) [9], but also in
two small Mo–S–Mo bridging angles (61.00(5)° and 61.18(6)°),
of 4 shows two sharp m
(CO) bands at 1934 and 1835 cmꢀ1, which
correspond to the terminal CO ligands. Based on these spectro-
which are consistent with those (60.96(1)° and 60.99(2)°) in [(g5
-
C5H5)MoCl(
l
-SMe)2]2 [33], but narrower than those in [(g5
-
scopic data and the elemental analysis, the molecular structure
C5H5)Mo(
l
-SMe)2]2 (range 63.6(1)–63.9(1)°) [32]. The S(1)ꢁꢁꢁS(2)
of 4 is suggested as [(g
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)4(SC(S)-
distance is 3.930 Å, which is significantly larger than the sum of
the covalent radius of two sulfur atoms, and this indicates no
bonding interactions between them. In addition, the cyclopentadi-
enyl rings of the doubly-bridged ligand are slightly twisted with
respect to each other, which is evident in the torsion angle
\Cp(centroid)–Mo(1)–Mo(2)–Cp(centroid) (4.9°). Comparing with
the highly symmetrical structure of compound 1 [9], this minimal
twist may partly alleviate the strain of the seriously bent doubly-
bridged ligand.
NEt2)2, which is the normal expected product. However, an
alternative structure in which both of the two SC(S)NEt2 ligands
bridge over the two Mo atoms cannot be ruled out. The corre-
sponding non-bridged analog
(g
5-C5H5)M(CO)2[SC(S)NR2] (M =
Mo, or W) has been synthesized from the reactions of the biscyclo-
pentadienyl dinuclear carbonyl complex Cp02M2(CO)6 with
[R2NC(S)S]2 under thermal or photochemical conditions [23,24].
Clearly complex 1 shows similar reactivity towards [Et2NC(S)S]2
as the respective non-bridged biscyclopentadienyl analogs.

B.-L. Zhu et al. / Polyhedron 42 (2012) 57–65
61
Me2
C
Me2
Si
PhC CPh
toluene,
1
CO
Mo
OC Mo
OC
CO
C
C
Ph Ph
5
Scheme 5. Reaction of 1 with C2Ph2.
2.5. Reaction of 1 with C2Ph2
Complex 1 reacts with C2Ph2 in refluxing toluene overnight to
afford compound 5, which is isolated as an air-stable dark brown
crystal (Scheme 5). The IR spectrum of 5 contains three strong
m
(CO) bands in the range 1977–1914 cmꢀ1, indicating the existence
of terminal CO ligands. The 1H NMR spectrum shows three peaks at
5.56, 5.31 and 5.00 ppm for the protons in each cyclopentadienyl
ring, two singlets at 0.68 and 0.65 ppm for the different CH3 pro-
tons in the SiMe2 group, and two singlet peaks at 1.58 and
0.49 ppm for the different CH3 protons in the CMe2 group. Com-
pared with the typical region for CMe2 protons, the signal at
0.49 ppm is approximately 0.9 ppm shifted to high field, which
indicates an apparent shielding effect from a nearby phenyl ring
on the corresponding methyl protons. This hypothesis is further
confirmed by X-ray structural data of 5, which is assigned as
[(g l-PhC„CPh). Two carbonyl
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)4(
Fig. 5. ORTEP diagram of [(
g
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)4(
l
-C2Ph2) (5). Thermal
groups from each Mo atom in complex 1 are substituted by a bridg-
ing PhC„CPh ligand. Similar reactions of the non-bridged biscyclo-
pentadienyl analog Cp2Mo2(CO)6 [26], singly-bridged analog
SiMe2[Cp0Mo(CO)3]2 [27] and fulvalene [28,29] dinuclear complex
FvMo2(CO)6 with alkynes have been reported to give the corre-
ellipsoids are shown at the 30% level. Hydrogens are omitted for clarity. Selected
bond lengths [Å] and angles [°] are as follows: Mo(1)–Mo(2) 2.913(1), Mo(1)–C(1)
1.971(4), Mo(1)–C(2) 1.980(5), Mo(1)–C(5) 2.192(5), Mo(1)–C(6) 2.198(4), Si(1)–
C(19) 1.857(5), Si(1)–C(24) 1.846(5), C(5)–C(6) 1.362(6) Mo(1)–Cp(centroid) 2.003,
Mo(2)–Cp(centroid) 2.011, \C(19)–Si(1) –C(24) 96.4(2), \C(20)–C(29)–C(25)
107.3(3), \Mo(1)–C(5)–Mo(2) 82.8(2), \Mo(1)–C(6)–Mo(2) 83.9(2), \Cp(cen-
troid)–Mo(1)–Mo(2)–Cp(centroid) 5.0, \Cp–Cp fold angle, 136.7.
sponding products containing an l-RC„CR structure, which show
the consistent reactivity of 1, and its respective non-, or singly-
bridged analogs towards C2Ph2.
The molecular structure of complex 5 is presented in Fig. 5. It has
an approximate symmetry plane passing though the bridged car-
bon, the silicon atoms and the center of the Mo–Mo line. The Mo–
Mo bond distance of 2.9126(10) Å in 5 is very close to those in the
Me2
C
Me2
PR3/toluene
+
Si
1
non-bridged analogs Cp2Mo2(CO)4(
2.977(1) Å, R = Et; 2.956(1) Å, R = Ph) [35,36] and singly-bridged
analog (SiMe2)[Cp02Mo2(CO)4](
-RC„CR) (2.966(1) Å, R = CO2Me)
[27], whereas it is much shorter than that in 1 [3.433(1) Å] [9],
which results in a significant bending of the [(
5-C5H3)2(CMe2)
l
-RC„CR0) (2.980(1) Å, R = H;
Mo
Mo PR3
R3P Mo
(CO)3 (CO)2
6 (R= Ph)
l
7 (R = OPh)
g
Scheme 6. Reaction of 1 with PR3.
(SiMe2)] ligand (\Cp–Cp fold angle 136.7°) with respect to that
(149.3°) in 1. The alkyne is coordinated to the two Mo metals in a
nearly symmetrical way, with its alkyne C–C bond almost perpen-
dicular to the Mo–Mo line. The bridging alkyne is also tipped over
to the CMe2 bridge side of the doubly-bridged ligand, which possi-
bly owing to the smaller steric effect of the CMe2 bridge compared
with the SiMe2 bridge makes it adopt a predominate configuration,
and it also well accounts for the proton peaks of CMe2 being shifted
to the high field mentioned above. Two phenyl planes are almost
perpendicular to each other, with a dihedral angle of 72.6°. In addi-
tion, there exists a slight torsion between the two cyclopentadienyl
rings (\Cp(centroid)–Mo(1)–Mo(2)–Cp(centroid) = 5.0°).
products under photochemical conditions [39]. Similarly, for com-
parison, the reactions of complex 1 with PR3 (R = Ph, OPh) were ex-
plored (Scheme 6).
Complex 1 reacts with PPh3 in refluxing toluene to only give
the mono-substituted complex [(g
5-C5H3)2(CMe2)(SiMe2)]Mo2
(CO)5(PPh3) (6); no di-substituted product was observed even in
the presence of excess PPh3 ligand. While 1 reacts with P(OPh)3
under the same conditions, both the mono-substituted derivative
[(
tuted derivative [(
g
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)5(P(OPh)3) (7) and the di-substi-
g
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)4(P(OPh)3)2 (8)
could be isolated. Although the electron-donating ability of the
PPh3 ligand is stronger than that of P(OPh)3, here the steric effect
of bulky PPh3 group seems to be the main factor that leads to the
absence of the di-PPh3 substituted product. In other words, complex
1 shows similar reactivity to its respective singly-bridged analog
towards PR3, but different to its non-bridged analog.
2.6. Reaction of 1 with PR3 (R = Ph, OPh)
The reactions of the non-bridged biscyclopentadienyl dinuclear
complexes Cp2M2(CO)6 (M = Mo, W) [37] and fulvalene dinuclear
complexes FvM2(CO)6 (M = Mo, W) [38] with PR3 have been re-
ported, and these generally resulted in ionic products. However,
Complex 6 was isolated as an air-stable green crystal. The IR
the singly-bridged analog [(
g
5-C5H4)2(CH2)]Mo2(CO)6 reacted with
spectrum of 6 contains three strong
m(CO) bands in the range
PR3 to give the corresponding mono-substituted or di-substituted
1973–827 cmꢀ1, corresponding to the terminal CO ligands. The

62
B.-L. Zhu et al. / Polyhedron 42 (2012) 57–65
Fig. 6. ORTEP diagram of [(
g
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)4(P(OPh)3)2 (8). Thermal ellipsoids are shown at the 30% level. Hydrogens are omitted for clarity. Selected bond
lengths [Å] and angles [°] are as follows: C(7)–C(8) 1.529(8), C(3)–Si(1) 1.837(7), Mo(1)–Mo(1A) 3.563, Mo(1)–C(1) 1.962(7), Mo(1)–C(2) 1.981(8), Mo(1)–P(1) 2.338(2),
Mo(1)–Cp(centroid) 2.019, \C(3)–Si(1)–C(3A) 96.9(4), \C(7)–C(8)–C(7A) 107.8(7), \Mo(1)–C(1)–O(1) 173.9(6), \Mo(1)–C(2)–O(2) 171.9(6), \Cp–Cp fold angle 153.7,
\Cp(centroid)–Mo(1)–Mo(2)–Cp(centroid) 0.
1H NMR spectrum shows five peaks at d 5.41 (1H), 5.13 (1H), 5.02
(1H), 4.90 (1H) and 4.38 (2H) ppm for the protons of each cyclo-
pentadienyl ring, which are consistent with the proposed asym-
metric structure of 6. It also shows two singlets at 0.48 and
0.46 ppm for the different CH3 protons in the SiMe2 group, and
two singlets at 1.45 and 1.41 ppm for the different CH3 protons
in the CMe2 group. Complex 7 exhibits similar spectroscopic pat-
terns to 6.
conformations, which were both determined by X-ray diffraction.
The second is that the detailed structure of complex 3a, as a
representative example for this type of binuclear compound,
[Cp0Mo(SPh)2]2, has been determined for the first time. After a
comparison with its respective non-bridged and singly-bridged
analogs, the doubly-bridged biscyclopentadienyl dinuclear com-
plex 1 shows mostly similar reactivity and properties, except with
better solubility.
Complex 8 was obtained as an air-stable green crystal. Its IR
spectrum contains three strong m(CO) bands in the range 1981–
1878 cmꢀ1, consistent with the presence of terminal CO ligands.
The 1H NMR spectrum shows three peaks at 4.95, 4.07, and
3.73 ppm for the protons of each cyclopentadienyl ring, two sing-
lets at 0.20 and 0.13 ppm for the SiMe2 protons, and two singlets
at 1.15 and 1.04 ppm for the CMe2 protons. In the molecular struc-
ture of 8 (Fig. 6), there is a perfect symmetry plane passing though
the bridged carbon (C(8)) and silicon (Si(1)) atoms and the center
of the Mo–Mo line. Two bulky substituted P(OPh)3 groups are coor-
dinated to the corresponding Mo atom in a cis arrangement and are
extended outside in a steric favorable way. The Mo–Mo bond dis-
4. Experimental
4.1. General procedures
Schlenk and vacuum line techniques were employed for all
manipulations. All solvents were distilled from the appropriate
drying agents under argon prior to use. 1H and 31P{1H} NMR spec-
tra were recorded with a Bruker AV300 instrument (1H at 300 MHz
and 31P{1H} at 121.5 MHz), while IR spectra were recorded as KBr
disks on a NICOLET 560 E.S.P. FTIR spectrometer. Elemental analy-
ses were performed on a Perkin-Elmer 240C analyzer. The complex
tance is 3.563 Å, which is longer than that in complex
1
[(g
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)6 (1) was prepared according to
the literature method [9]. Irradiations were conducted using a
quartz glass photochemical reactor utilizing a 500 W high-pressure
mercury lamp as the light source.
[3.433(1) Å] [9], this leads to a wider Cp–Cp fold angle (153.7°)
with respect to that (149.3°) in 1. The lengthened Mo–Mo bond
is most likely attributed to avoidance of non-bonding interactions
between the highly symmetrical and eclipsed carbonyl and phos-
phite ligands, in addition to alleviation of strain of the bended dou-
bly-bridged biscyclopentadienyl ligand.
4.2. Reaction of 1 with I2
3. Conclusions
A solution of 58 mg (0.10 mmol) of 1 and 30 mg (0.12 mmol) of
I2 in 20 mL of CH2Cl2 was stirred for 6 h at room temperature. After
removal of the solvent, the residue was chromatographed on an
alumina column using petroleum ether/CH2Cl2 (2:1) as the eluent.
The only red band afforded 20 mg (24%) of 2A as dark-red crystals.
In summary, the thermal or photochemical reactions of
[(g
5-C5H3)2(CMe2)(SiMe2)]Mo2(CO)6 (1), featuring rigid doubly-
bridged biscyclopentadienyl ligands and an unusually long Mo–
Mo bond (3.433(1) Å) in the structure, with a series of classic
substrates, including I2, Ph2E2 (E = S, Se), [Et2NC(S)S]2, C2Ph2 and
PR3 (R = Ph or OPh), are reported. Among all the results obtained,
two are especially noteworthy. The first is that the di-iodo com-
plexes 2A and 2B have the same structural formula but different
For compound 2A, mp: 170 °C (dec.). Anal. Calc. for C21H18 2-
I
Mo2O6Si: C, 30.02; H, 2.16. Found: C, 29.95; H, 2.15%. 1H NMR
(CDCl3) d (ppm): 5.70 (m, 4H, Cp–H), 5.47 (m, 2H, Cp–H), 1.68 (s,
3H, C–Me), 1.57 (s, 3H, C–Me), 0.77 (s, 3H, Si–Me), 0.43 (s, 3H,
Si–Me). IR (KBr) [m
CO/cmꢀ1]: 2050 s, 2034 s, 1990 s, 1972 s, 1946 s.

B.-L. Zhu et al. / Polyhedron 42 (2012) 57–65
63
A solution of 58 mg (0.10 mmol) of 1 and 76 mg (0.30 mmol) of
4.6. Reaction of 1 with C2Ph2
I2 in 20 mL of benzene was stirred for 1 h at room temperature.
After removal of the solvent, the residue was chromatographed
on an alumina column using petroleum ether/CH2Cl2 (2:1) as the
eluent. The only red band afforded 45 mg (54%) of 2B as dark-red
crystals.
A toluene (20 mL) solution of 58 mg (0.10 mmol) of 1 and 20 mg
(0.11 mmol) of C2Ph2 was refluxed overnight. After removal of the
solvent, the residue was chromatographed on an alumina column
using petroleum ether/CH2Cl2 (3:1) as the eluent. The only brown
band afforded 50 mg (71%) of 5 as dark brown crystals.
For compound 5, mp: 212 °C. Anal. Calc. for C33H28Mo2O4Si: C,
55.94; H, 3.98. Found: C, 55.90; H, 3.95%. 1H NMR (CDCl3) d
(ppm): 7.33–7.00 (m, 10H, Ph–H), 5.56 (m, 2H, Cp–H), 5.31 (m,
2H, Cp–H), 5.00 (m, 2H, Cp–H), 1.58 (s, 3H, C–Me), 0.68 (s, 3H,
For compound 2B, mp: 170 °C (dec.). Anal. Calc. for C21H18 2-
I
Mo2O6Si: C, 30.02; H, 2.16. Found: C, 30.04; H, 2.21%. 1H NMR
(CDCl3) d (ppm): 5.75 (m, 4H, Cp–H), 5.49 (m, 2H, Cp–H), 1.72 (s,
3H, C–Me), 1.60 (s, 3H, C–Me), 0.81 (s, 3H, Si–Me), 0.47 (s, 3H,
Si–Me). IR (KBr) [m
CO/cmꢀ1]: 2038 s, 1990 s, 1964 s, 1952 s, 1936 s.
Si–Me), 0.65 (s, 3H, Si–Me), 0.49 (s, 3H, C–Me). IR (KBr) [mCO
/
cmꢀ1]: 1977 s, 1946 s, 1914 s.
4.3. Reaction of 1 with Ph2S2
A toluene (20 mL) solution of 100 mg (0.17 mmol) of 1 and
74 mg (0.34 mmol) of Ph2S2 was refluxed overnight. After removal
of the solvent, the residue was chromatographed on an alumina
column using petroleum ether/CH2Cl2 (3:1) as the eluent. The only
blue band afforded 20 mg (14%) of 3a as dark blue crystals.
For compound 3a, mp: 152 °C (dec.). Anal. Calc. for C39H38Mo2
S4Si: C, 54.79; H, 4.48. Found: C, 54.60; H, 4.38%. 1H NMR (CDCl3)
d (ppm): 8.42 (m, 4H, Ph–H), 7.50–7.27 (m, 6H, Ph–H), 6.87 (m,
10H, Ph–H), 5.50 (m, 2H, Cp–H), 5.24 (m, 2H, Cp–H), 4.31 (m, 2H,
Cp–H), 2.12 (s, 3H, C–Me), 1.53 (s, 3H, C–Me), 0.90 (s, 3H, Si–Me),
0.60 (s, 3H, Si–Me).
A solution of 100 mg (0.17 mmol) of 1 and 74 mg (0.34 mmol)
of Ph2S2 in 40 mL of toluene was placed in a quartz irradiation ves-
sel. The reaction mixture was photolyzed for 0.5 h. After removal of
the solvent, the residue was chromatographed on an alumina col-
umn using petroleum ether/CH2Cl2 (3:1) as the eluent. The only
blue band afforded 50 mg (34%) of 3a as dark blue crystals.
4.7. Reaction of 1 with PPh3
A toluene (20 mL) solution of 100 mg (0.17 mmol) of 1 and
100 mg (0.38 mmol) of PPh3 was refluxed overnight. After removal
of the solvent, the residue was chromatographed on an alumina
column using petroleum ether/CH2Cl2 (4:1) as the eluent. The only
green band afforded 60 mg (43%) of 6 as dark green crystals.
For compound 6, mp: 157 °C. Anal. Calc. for C38H33Mo2O5PSi: C,
55.62; H, 4.05. Found: C, 55.42; H, 3.95%. 1H NMR (CDCl3) d (ppm):
7.41 (m, 15H, Ph–H), 5.41 (m, 1H, Cp–H), 5.13 (m, 1H, Cp–H), 5.02
(m, 1H, Cp–H), 4.90 (m, 1H, Cp–H), 4.40 (m, 2H, Cp–H), 1.45 (s, 3H,
C–Me), 1.41 (s, 3H, C–Me), 0.48 (s, 3H, Si–Me), 0.46 (s, 3H, Si–Me).
31P{1H} NMR (CDCl3) d (ppm) 77.0 (s). IR (KBr) [ CO/cmꢀ1]: 1973 s,
m
1898 s, 1870 s, 1827 s.
4.8. Reaction of 1 with P(OPh)3
A toluene (20 mL) solution of 80 mg (0.14 mmol) of 1 and 90 mg
(0.29 mmol) of P(OPh)3 was refluxed overnight. After removal of
the solvent, the residue was chromatographed on an alumina col-
umn using petroleum ether/CH2Cl2 (4:1) as the eluent. The first
band (green) afforded 40 mg (33%) of 7 as dark green crystals,
The second band (green) afforded 20 mg (12%) of 8 as dark green
crystals.
4.4. Reaction of 1 with Ph2Se2
A toluene (20 mL) solution of 100 mg (0.17 mmol) of 1 and
106 mg (0.34 mmol) of Ph2Se2 was refluxed overnight. After re-
moval of the solvent, the residue was chromatographed on an alu-
mina column using petroleum ether/CH2Cl2 (3:1) as the eluent. The
only blue band afforded 10 mg (6%) of 3b as dark blue crystals.
For compound 3b, mp: 190 °C. Anal. Calc. for C39H38Mo2Se4Si: C,
44.93; H, 3.67. Found: C, 44.65; H, 3.28%. 1H NMR (CDCl3) d (ppm):
8.42 (m, 4H, Ph–H), 7.59–7.27 (m, 6H, Ph–H), 7.08 (m, 4H, Ph–H),
6.90 (m, 6H, Ph–H), 5.39 (m, 2H, Cp–H), 5.06 (m, 2H, Cp–H), 4.30
(m, 2H, Cp–H), 2.15 (s, 3H, C–Me), 1.41 (s, 3H, C–Me), 0.92 (s, 3H,
Si–Me), 0.53 (s, 3H, Si–Me).
For compound 7, mp: 144 °C. Anal. Calc. for C38H33Mo2O8PSi: C,
52.55; H, 3.83. Found: C, 50.84; H, 4.55%. 1H NMR (CDCl3) d (ppm):
7.33–7.17 (m, 15H, Ph–H), 5.33 (m, 1H, Cp–H), 5.09–4.97 (m, 3H,
Cp–H), 4.20 (m, 1H, Cp–H), 3.96 (m, 1H, Cp–H), 1.33 (s, 3H, C–
Me), 1.19 (s, 3H, C–Me), 0.38 (s, 3H, Si–Me), 0.29 (s, 3H, Si–Me).
31P{1H} NMR (CDCl3) d (ppm): 187.2 (s). IR (KBr) [ CO/cmꢀ1]:
m
1988 s, 1905 s, 1885 s, 1842 s.
A solution of 100 mg (0.17 mmol) of 1 and 106 mg (0.34 mmol)
of Ph2Se2 in 40 mL of toluene was placed in a quartz irradiation
vessel. The reaction mixture was photolyzed for 0.5 h. After re-
moval of the solvent, the residue was chromatographed on an alu-
mina column using petroleum ether/CH2Cl2 (3:1) as the eluent. The
only blue band afforded 60 mg (34%) of 3b as dark blue crystals.
For compound 8, mp: 153 °C. Anal. Calc. for C55H48Mo2O10P2Si:
C, 57.40; H, 4.20. Found: C, 56.47; H, 5.01%. 1H NMR (CDCl3) d
(ppm): 7.36–7.12 (m, 30H, Ph–H), 4.97 (m, 2H, Cp–H), 4.07 (m,
2H, Cp–H), 3.73 (m, 2H, Cp–H), 1.15 (s, 3H, C–Me), 1.03 (s, 3H,
C–Me), 0.20 (s, 3H, Si–Me), 0.12 (s, 3H, Si–Me). 31P{1H} NMR
(CDCl3) d (ppm): 188.5 (s). IR (KBr) [m
CO/cmꢀ1]: 1981 s, 1906 s,
1876 s.
4.5. Reaction of 1 with [Et2NC(S)S]2
4.9. Crystallographic studies
A toluene (25 mL) solution of 100 mg (0.17 mmol) of 1 and
100 mg (0.34 mmol) of [Et2NC(S)S]2 was refluxed overnight. Dur-
ing this time the solution turned from dark green to red. After re-
moval of the solvent, the residue was chromatographed on an
alumina column using petroleum ether/CH2Cl2 (4:1) as the eluent.
The band (orange) afforded 90 mg (64%) of 4 as orange-red crystals.
For compound 4, mp: 140 °C. Anal. Calc. for C29H38Mo2N2O4S4Si:
C, 42.13; H, 4.63. Found: C, 42.12; H, 4.61%. 1H NMR (CDCl3) d
(ppm): 5.46 (m, 6H, Cp–H), 3.64 (m, 8H, N–CH2), 1.53 (s, 3H, C–
Me), 1.45 (s, 3H, C–Me), 1.16 (t, 12H, NC–Me), 0.37 (s, 3H, Si–
Single crystals of complexes 2A, 2B, 3a, 5 and 8, suitable for
X-ray diffraction, were obtained from hexane/CH2Cl2 (1:1)
solution. Data collection was performed on a BRUKER SMART
1000, using graphite-monochromated Mo K
a radiation (x-2h
scans, k = 0.71073 Å). Semi-empirical absorption corrections were
applied for all complexes. The structures were solved by direct
methods and refined by full-matrix least-squares. All calculations
were carried out using the SHELXL-97 program system. The crystal
data and a summary of the X-ray data collection are presented in
Tables 1 and 2.
Me), 0.30 (s, 3H, Si–Me). IR (KBr) [m
CO/cmꢀ1]: 1934 s, 1835 s.

64
B.-L. Zhu et al. / Polyhedron 42 (2012) 57–65
Table 1
Crystal data and summary of X-ray data collection for 2A, 2B, 3a and 5.
2A
2B
3a
5
Empirical formula
Formula weight
T (K)
C
21H18I2Mo2O6Si
C21H18I2Mo2O6Si
840.12
293(2)
C39H38Mo2S4Si
854.90
293(2)
C33H28Mo2O4Si
708.52
293(2)
840.12
293(2)
Crystal system
Space group
a (Å)
b (Å)
c (Å)
orthorhombic
Pbca
14.703(3)
18.676(4)
18.834(4)
90
monoclinic
P2(1)/m
7.943(3)
20.144(7)
8.679(3)
90
monoclinic
P2(1)/n
11.540(4)
17.80(8)
18.056(9)
90
orthorhombic
P2(1)2(1)2(1)
10.535(4)
13.552(5)
19.910(8)
90
a
(°)
b (°)
90
90
5172(2)
8
2.158
109.307(5)
90
1310.5(8)
2
2.129
3.391
101.820(11)
90
3630(17)
4
1.564
0.982
90
90
c
(°)
V (Å3)
2842.5(19)
4
1.656
Z
Dcalc (g cmꢀ3
)
l
(mmꢀ1
)
3.437
0.962
F(000)
3168
792
1736
1424
Crystal size (mm)
Maximum 2h (°)
0.14 ꢂ 0.12 ꢂ 0.10
0.36 ꢂ 0.20 ꢂ 0.16
0.20 ꢂ 0.20 ꢂ 0.10
0.22 ꢂ 0.20 ꢂ 0.16
50.00
52.84
52.92
52.82
Reflections collected
Independent reflections/Rint
Number of parameters
GOF on F2
13429
4526/0.0836
346
7558
2761/0.0392
154
20362
7438/0.0736
478
13530
5805/0.0372
365
1.017
1.086
1.018
1.013
R1, wR2 [I > 2
r
(I)]
0.0529, 0.0626
0.1120, 0.0745
0.658
0.0334, 0.0635
0.0586, 0.0692
0.835
0.0458, 0.0802
0.1129, 0.0962
0.849
0.0339, 0.0642
0.0535, 0.0708
0.369
R1, wR2 (all data)
Largest peak in final difference map (e Åꢀ3
)
respectively. These data can be obtained free of charge via http://
www.ccdc.cam.ac.uk/conts/retrieving.html, or from the Cambridge
Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ,
UK; fax: (+44) 1223–336-033; or e-mail: deposit@ccdc.cam.ac.uk.
Table 2
Crystal data and summary of X-ray data collection for 8.
8
Empirical formula
Formula weight
T (K)
C55H48Mo2O10P2Si
1150.84
293(2)
References
Crystal system
Space group
a (Å)
b (Å)
c (Å)
orthorhombic
Pnma
17.303(5)
29.749(9)
9.972(3)
90
90
90
5133(3)
4
1.489
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a
(°)
b (°)
c
(°)
V (Å3)
Z
Dcalc (g cmꢀ3
)
l
(mmꢀ1
)
0.633
2344
F(000)
Crystal size (mm)
Maximum 2h (°)
Reflections collected
Independent reflections/Rint
Number of parameters
GOF on F2
0.22 ꢂ 0.18 ꢂ 0.16
52.88
28503
5364/0.1662
325
1.030
R1, wR2 [I > 2
r
(I)]
0.0667, 0.1128
0.1540, 0.1490
0.512
R1, wR2 (all data)
Largest peak in final difference map (e Åꢀ3
)
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Acknowledgments
We sincerely thank Prof. Robert J. Angelici for improving the
English for this article. We also gratefully acknowledge financial
support from the National Natural Science Foundation of China
(Grants 21002069 and 21072101), the Scientific Research Founda-
tion for the Returned Overseas Chinese Scholars, State Education
Ministry, and the Talent Fund Projects for the Introduced Scholar
in Tianjin Normal University (No. 5RL088).
Appendix A. Supplementary material
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CCDC 853219, 853220, 853221, 731548 and 853222 contain the
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