Synthesis of diphenylmethylene bridged fluorenyl cyclopentadienyl lanthanocene complexes with Cs symmetry and crystal structures of the ate complexes [Li(thf)4][LnCl2{(C13H8)CPh 2(C5</

Article abstract of DOI:10.1039/a904223g

The reaction of anhydrous lanthanide chlorides LnCl₃ with the dilithium salt of (C₁₃H₉)CPh₂(C₅H₅) in thf at ambient temperature led to the formation of the 'ate' complexes [Li(thf)₄

Full text of DOI:10.1039/a904223g

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Synthesis of diphenylmethylene bridged fluorenyl cyclopentadienyl
lanthanocene complexes with Cs symmetry and crystal structures
of the ate complexes [Li(thf)4][LnCl2{(C13H8)CPh2(C5H4)}] and
[Li(thf)4][Ln(BH4)2{(C13H8)CPh2(C5H4)}] (Ln ؍ Nd or La)
Changtao Qian,* Wanli Nie and Jie Sun
Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry,
Chinese Academy Of Sciences, 354 Fenglin Lu, Shanghai 200032, China.
E-mail: qianct@pub.sioc.ac.cn; Fax: 0086-21-64166128
Received 26th May 1999, Accepted 22nd July 1999
The reaction of anhydrous lanthanide chlorides LnCl3 with the dilithium salt of (C13H9)CPh2(C5H5) in thf at ambient
temperature led to the formation of the ‘ate’ complexes [Li(thf)4][LnCl2{(C13H8)CPh2(C5H4)}] (Ln = Lu 1 or Y 2).
Treatment of [Ln(BH4)3(thf)3] with 3 equivalents of (C13H8)CPh2(C5H4)Li2 in thf solution gave the anionic complexes
[Li(thf)4][Ln(BH4)2{(C13H8)CPh2(C5H4)}] (Ln = La 3 or Nd 4). The crystal structures of complexes 1, 3, 4 were
determined and indicated that they existed as discrete cation and anion pairs, which showed two crystallographically
independent molecules in the unit cell.
because the intermediates can be isolated more easily than in
Introduction
the case of the Group 4 metallocenes.3
Since the discovery of the first stereorigid chiral ansa metallo-
Until now most of the work reported was on compounds
cene complex1 and the application of such compounds as
stabilized by bis(pentamethylcyclopoentadienyl) or closely
homogeneous catalysts in stereospecific polymerization of
related ligand systems.4 In our previous work, we have
α-olefins to polymers with stereoregular microstructures, a wide
reported C2 symmetric bis(indenyl) ansa-lanthanocene
variety of metallocene catalysts from Groups 3 and 4 have now
complexes.5 So far, no lanthanocene complexes with ansa-
been prepared. The tacticity of polypropylene varies predict-
ably with the structure of the ansa metallocene catalysts: C2
symmetric metallocenes produce highly isotactic polypropyl-
ene; C1 metallocenes also produce isotactic polypropylene, but
bonded fluorenyl ligands have been reported. In this paper we
report the synthesis and structure of some representative ‘ate’
complexes: tetra(tetrahydrofuran) lithium dichloro(fluoren-9-
yldiphenylmethylcyclopentadienyl) lanthanidates and lithium
(fluoren-9-yldiphenylmethylcyclopentadienyl)bis(tetrahydro-
borato) lanthanidates which should prove useful as precursors
to lanthanocene() complexes such as hydrides and alkyls.
generally with less stereospecificity; syndiotactic polypropylene
has been produced using essentially a single type of Cs sym-
metric ansa-metallocene catalyst.2 However, the chemistry of
ansa-lanthanocene has been very limited, especially when com-
pared with that of the Group 4 metallocenes. Since the metal-
locenes of the rare earth elements are isoelectronic in structure
with Group 4 cationic alkyl metallocene complexes d0 MCp2Rϩ
(Cp = C5H5). This analogy has been used in the design of olefin
polymerization catalysts. A potentially significant advantage of
these catalysts is that they are single-component catalysts; no
cocatalyst (MeAlO)n (MAO) is needed. They can also catalyse
the polymerization of ethylene and polar monomer without the
cocatalyst MAO and exhibit high activity. Moreover, this fact
facilitates significantly the study of the α-olefin polymerization
mechanism and the influence of the metal–ligand environment
on the structure and properties of the resultant polymer
Results and discussion
Synthesis
The ate complexes [Li(thf)4][LnCl2{(C13H8)CPh2(C5H4)}] (Ln =
Lu 1 or Y 2) were synthesized by using a reaction between a
dilithio salt of an ansa ligand and an anhydrous lanthanide
chloride (Scheme 1). These complexes are readily dissolved in
thf, but just sparingly soluble in toluene at room temperature.
They remain air and moisture sensitive, whether in the solid
or solution phase. We attempted to extend this chemistry to
light lanthanide elements, but failed. This can be explained by
Scheme 1
J. Chem. Soc., Dalton Trans., 1999, 3283–3287
This journal is © The Royal Society of Chemistry 1999
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Table 1 The 1H NMR data (δ, J/Hz) of complexes 1–3 in [2H8]thf at 25 ЊC (300 MHz)
Complex
δCH(Ph)
δCH(fluorene)
δCH(Cp)
1
6.98 (t, 2 H, J = 7.1)
7.09 (m, 4 H)
7.90 (d, 2 H, J = 7.52)
8.00 (d, 2 H, J = 8.2)
6.97 (t, 2 H, J = 7.1)
7.09 (m, 4 H)
7.90 (d, 2 H, J = 7.6)
8.01 (d, 2 H, J = 8.2)
7.30 (m, 2 H)
7.15–7.32 (m, 2 H)
8.44 (m, 6 H)
6.52 (d, 2 H, J = 8.69)
6.81 (t, 2 H)
7.22 (t, 2 H)
8.08 (d, 2 H, J = 7.89)
6.48 (d, 2 H, J = 8.7)
6.84 (t, 2 H)
7.10 (t, 2 H)
8.04 (d, 2 H, J = 9.2)
6.98 (t, 2 H)
5.81 (t, 2 H, J = 2.6)
5.90 (t, 2 H, J = 2.6)
2
3
5.82 (t, 2 H, J = 2.6)
5.92 (t, 2 H, J = 2.6)
7.10 (t, 2 H)
7.95 (d, 2 H, J = 8.0)
8.30 (d, 2 H, J = 7.8)
6.31 (t, 2 H, J = 2.6)
6.74 (t, 2 H, J = 2.6)
Scheme 2
Table 2 Selected bond lengths (Å) and angles (Њ) for complex 1
the steric considerations which determine the stability and
structure of lanthanide complexes. The smaller radius of the
Cl group could only match the steric demand of the heavy
lanthanide elements.
Lu–Cl(1)
Lu–Cl(2)
Lu–C(1)
Lu–C(6)
Lu–C(7)
Lu–C(12)
Lu–C(13)
Lu–C(15)
Lu–C(16)
Lu–C(17)
Lu–C(18)
Lu–C(19)
2.496(2)
2.501(2)
2.631(5)
2.818(5)
2.841(5)
2.673(6)
2.570(6)
2.561(5)
2.567(5)
2.615(5)
2.626(5)
2.577(5)
Cl(1)–Lu–Cl(2)
Cl(1)–Lu–C(13)
Cl(2)–Lu–C(13)
Cl(1)–Lu–C(15)
96.48(7)
126.3(1)
124.8(1)
126.6(1)
126.7(1)
126.4(4)
125.8(4)
101.7(4)
124.9(4)
124.3(4)
103.5(4)
The usual route to synthesis of organolanthanide tetra-
hydroborates is by the reaction of a halide precursor with
LiBH4 or NaBH4.6 Besides [(thf)2(BH4)2Nd(µ-η7 :η7-C7H7)Nd-
(BH4)2(thf)2]7 and [{Nd(COT)(BH4)(thf)}2],8 which were
obtained from the reaction of Nd(BH4)3(thf)n (n = 2 or 3) with
KC7H9 or K2C8H8 respectively, no ansa-(cyclopentadienyl)-
lanthanide tetrahydroborate complexes have been isolated
directly by the reaction of Nd(BH4)3(thf)n with cyclopentadi-
enyl anionic reagents. Compounds [Li(thf)4][Ln{(µ-H)3BH)2}-
{(C13H8)CPh2(C5H4)}] (Ln = La 3 or Nd 4) were synthesized
directly by the reaction of [Ln(BH4)3(thf)3] with (C13H8)CPh2-
(C5H4)Li2 in thf (Scheme 2). By slow diffusion of hexane
into the concentrated thf solution, we got single crystals suit-
able for X-ray diffraction. The crystal structures indicated
that they belonged to the class of ‘ate’ complexes instead of
the expected homometallic compounds or heterometallic
ones. Taking into consideration the larger radius and the ver-
satile bonding modes of the BH4 group in comparison with
chloride, it would be expected that the tetrahydroborate com-
plexes of most of the rare earth elements should be obtain-
able. However in this series, we only isolated the light lanthan-
ide tetrahydroborate complexes. Any attempt to obtain yttrium
tetrahydroborate complex from the reaction of [Y(BH4)3(thf)3]
with the dilithium salt of the ligand failed and unfortunately
a non-crystallizing oil formed which can not be purified or
further characterized.
Cl(2)–Lu–C(15)
C(1)–C(13)–C(14)
C(12)–C(13)–C(14)
C(13)–C(14)–C(15)
C(14)–C(15)–C(16)
C(14)–C(15)–C(19)
C(20)–C(14)–C(26)
doublet pattern. Since the additional phenyl substituents show
signals in the same region as the fluorenyl ligand, their spectra
are too complicated accurately to calculate the 1H, 1H coupling
constants. The data are collected in Table 1. Since compound 4
exhibits paramagnetic chemical shifts it is very difficult to
assign its 1H NMR spectrum.
Molecular structure
X-Ray diffraction quality crystals were grown from thf solu-
tion. All the crystal structures of these three ate complexes con-
sist of isolated ion pairs. Selected bond lengths and internal
angles are given in Tables 2 and 3. The molecular structures of 1
and 4 are shown in Figs. 1 and 2, respectively. In the anion the
complexes adopt the pseudotetrahedral, bent metallocene
Ϫ
motif commonly observed for Cp2LnX2 complexes.10,11 The
Ln–C (Cp ring, fluorene-ring) bond distances display the dis-
persion pattern observed in other ring-bridged organo-
lanthanide complexes with longer Ln–C (Cp ring, fluorene-
ring) distances for carbon atoms (C(6), C(7), C(17), C(18))
distal to the Ph2C bridge vs. proximal carbon atoms (C(13),
C(15)).4 The Ln–C (Cp ring) distances in these three complexes
are within the range expected for ansa-lanthanocene. However,
for the Ln–C (fluorene-ring), the metal–carbon bond distances
between Ln and C(6), C(7) are much longer than the proximal
Spectroscopic properties
In the case of diamagnetic complexes, the 1H NMR spectra of 1
and 2 were recorded in THF-d8, and that of 3 in C6D6. The
spectra show similar patterns for the four protons of the
cyclopentadienyl. The two pseudotriplets lay in the range δ 5.8–
6.7 with 1H, 1H coupling constants of 2.5–2.7 Hz. The protons
of the fluorenyl ligands give rise to a doublet, triplet, triplet,
3284
J. Chem. Soc., Dalton Trans., 1999, 3283–3287

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Table 3 Selected bond lengths (Å) and angles (Њ) for complexes 3 and 4
3(La)
4(Nd)
Ln–B(1)
Ln–B(2)
2.717(5)
2.713(5)
2.37(6)
2.43(4)
2.38(5)
2.52(5)
2.49(5)
2.40(4)
2.845(3)
3.001(3)
3.010(3)
2.861(3)
2.788(3)
2.763(3)
2.769(3)
2.828(4)
2.830(4)
2.769(3)
2.642(7)
2.658(6)
2.53(4)
2.38(6)
2.38(4)
2.39(4)
2.45(5)
2.45(5)
2.793(4)
2.946(4)
2.954(4)
2.806(4)
2.725(4)
2.701(4)
2.699(4)
2.771(4)
2.767(4)
2.708(4)
Ln–H(23)
Ln–H(24)
Ln–H(25)
Ln–H(27)
Ln–H(28)
Ln–H(29)
Ln–C(1)
Ln–C(6)
Ln–C(7)
Ln–C(12)
Ln–C(13)
Ln–C(15)
Ln–C(16)
Ln–C(17)
Ln–C(18)
Ln–C(19)
Fig. 2 An ORTEP drawing of the [Nd(BH4)2(C13H8)CPh2(C5H4)2]Ϫ
anion.
B(1)–Ln–B(2)
99.5(2)
126.6(3)
125.6(3)
104.1(2)
125.9(3)
125.8(3)
102.7(2)
99.3(2)
126.8(3)
125.3(3)
102.4(3)
125.5(3)
125.9(4)
103.1(3)
only that of 4 is discussed. This compound exists as discrete
cation and anion pairs, and shows two crystallographically
independent molecules in the unit cell. The Nd is bonded to the
cyclopentadienyl ring and fluorenyl ring in η5 fashion, and to
two BH4 ligands in symmetric geometry. The angle of B(1)–
Nd–B(2) (99.3(2)Њ) is almost equal to the value of Cl(1)–Nd–
Cl(2) in the anion [Nd(CpЉ)2Cl2]Ϫ, 99.3(1)Њ. The Nd–C (Cp ring)
distances range from 2.699(4) to 2.767(4) Å, average 2.729 Å.
The Nd–C (fluorene-ring) distances range from 2.725(4) to
2.954(4) Å, average 2.845 Å. The angle at the diphenylmethyl-
ene carbon C(13)–C(14)–C(15) 102.4(3)Њ is larger than in previ-
ously reported Group 4 metallocenes having a C5H4CR2C13H8
(R = Me or Ph) chelating ligand system.14 We believe that the
progressive increase in the Nd–C bond distances from the
bridgehead carbon C(13)(2.725(4)) to C(1)(2.793(4)), C(12)-
(2.806(4)), C(6)(2.946(4)), C(7)(2.954(4)) Å is due to the non-
bonding interaction between the two borate ligands. Similar
reasoning applies to the Nd–C bond distances to the cyclo-
pentadienyl moiety. The Nd–C(17) (2.771(4)) and Nd–C(18)
(2.767(4) Å) distances which are on average about 0.1 Å larger
than the other three are also due to the non-bonding interaction
between the two borate ligands, and the (dorsal/distal)carbon
and hydrogen atoms are responsible for the repulsion that gives
rise to this bond lengthening. The most remarkable structural
feature of the complex is the mode of attachment of the tetra-
hedral BH4 ligands. The two boron atoms have almost the same
ligation geometry. Each of them is linked to the metal centre via
a µ3-hydrogen bridging the B and the Nd atoms. This ‘ate’
co-ordination type of tetrahydroborate ligand has not been
encountered in organolanthanide tetrahydroborate com-
pounds, but is known in uranium compounds.15 The two Nd–B
distances (Nd–B(1) 2.642(7), Nd–B(2) 2.658(6) Å) which
may be compared with that of 2.664(25) Å in the monomeric
neodymium complex [Nd(C5H4CH2CH2OMe)2(BH4)]16b are
shorter than that of dimeric neodymium complexes (e.g.
2.875(6) and 2.941(6) in [{Nd{(COT)(BH4)(thf)}2]8). The
short distances are characteristic of tridentate BH4 ligands.
The six Nd–Hb bond distances for the tridentate groups are
not significantly different (2.53(4), 2.45(5), 2.39(4), 2.38(4) Å).
In each Nd–µ–H moiety two of the Nd–Hb bond distances
are equal (2.38(5) and 2.45(5) Å, respectively). The Nd–B–Hb
angles are equal to 64(2) or 72(2)Њ, whereas the two Nd–B–Ht
angles are almost linear (Nd–B(1)–Ht 173(3), Nd–B(2)–Ht
178(2)Њ). The tetrahedral BH4 groups seem much more distorted
than its ideal H–B–H angles of 109Њ28Ј. The bond distances
of B–Hb and B–Ht are not significantly different, varying
from 0.97(6) to 1.10(5) Å. In the FT-Raman spectrum the
sharp singlet at 2421 and 2221cmϪ1 are characteristic of tri-
dentate BH4 groups.
C(1)–C(13)–C(14)
C(12)–C(13)–C(14)
C(13)–C(14)–C(15)
C(14)–C(15)–C(16)
C(14)–C(15)–C(19)
C(20)–C(14)–C(26)
Fig. 1 An ORTEP9 drawing of the [LuCl2(C13H8)CPh2(C5H4)]Ϫ anion.
Ln–C(13) distance. This can be explained by the inclined
stereorigid planar fluorenyl ligation.
In the crystal structure of complex 1 the central metal Lu is
tetrahedrally co-ordinated to the bridging ligand and the two Cl
atoms with angle Cl(1)–Lu–Cl(2) 96.48(7)Њ and the bond
lengths Lu–Cl(1) 2.496(2) and Lu–Cl(2) 2.501(2) Å. Since the
Nd3ϩ radius is 0.15 Å larger than that of Lu3ϩ, this compound is
comparable to the anion [Nd(CpЈ)2Cl2]Ϫ 11 (CpЈ = C5Me5) where
the average Nd–Cl distance is 2.668(4) Å and Cl(1)–Nd–Cl(2) is
99.3(1)Њ. Since the chlorine atoms do not co-ordinate with the
lithium in these ate compounds, these values depart some-
what from those found in other classes of lutetium metallo-
cenes e.g. for [(R)-Me2SiCpЉ[(ϩ)-neomenthylCp]Lu(µ-Cl)2Li-
(OEt2)2]12 (CpЉ = Me4C5) (86.9(1)Њ; 2.569(4) Å and 2.571(4) Å)
and for achiral [CpЈ2Yb(µ-Cl)2Li(OEt2)2]10b (85.89Њ; Lu–Cl
2.586 and 2.584 Å), correcting for differences in Lu3ϩ and Yb3ϩ
eight-co-ordinate ionic radii,13 in which the longer Ln–Cl dis-
tance (>0.06–0.07 Å) and smaller Cl(1)–Ln–Cl(2) angle (<10Њ)
are caused by the bridging nature of the chlorides.
Complexes 3 and 4 have almost identical structures and so
J. Chem. Soc., Dalton Trans., 1999, 3283–3287
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Table 4 X-Ray diffraction data collection parameters for complexes 1, 3 and 4
1
3
4
Formula
M
C47H54Cl2LiLuO4
935.76
C47H62B2LaLiO4
858.47
C47H62B2LiNdO4
863.81
Crystal system
Space group
a/Å
b/Å
c/Å
α/Њ
β/Њ
Triclinic
P1 (no. 2)
12.529(5)
15.280(3)
12.247(3)
99.06(2)
100.53(2)
76.02(2)
2173(1)
293
Triclinic
P1 (no. 2)
12.422(3)
16.343(4)
12.337(4)
110.50(2)
103.16(2)
76.16(2)
2249(1)
293
Triclinic
P1 (no. 2)
12.415(6)
16.245(5)
12.337(5)
110.43(3)
103.23(4)
76.13(3)
2234(1)
293
γ/Њ
V/Å3
T/K
Z
2
2
9.85
7918
7522
2
µ(Mo-Kα)/cmϪ1
Reflections collected
Independent reflections
R, RЈ
24.35
8051
7659
0.037, 0.052
12.01
5026
4707
0.027, 0.036
0.032, 0.041
The cation [Li(thf)4]ϩ which exists in the three crystal struc-
tures is classical and quite similar to that in the complex
[Li(thf)4][Yb(t-BuCp)(NPh2)3].16 Each lithium is co-ordinated
by four oxygen atoms from four thf molecules forming a tetra-
hedral structure with Li–O distances ranging from 1.907(9) to
1.934(9) Å.
Since the single atom bridge of the Ph2C linker provides a
relatively rigid ansa-metallocene ligand framework and serves
to increase the dihedral angle between the cyclopentadienyl and
fluorenyl planes, this leads to ‘opening’ of the wedge between
the two planes where two BH4 or Cl groups can be located on
the metal to afford ate lanthanide complexes.
(cmϪ1): 3061m, 2986m, 2889m, 1595w, 1529m, 1436m, 1343s,
1327vs, 1002s, 667w, 438m and 286m.
Complex 2. A procedure similar to that for complex 1 was
adopted for YCl3 (1.40 g, 7.2 mmol), affording 2 as a yellow
crystalline product (0.94 g, 41%) (Found: C, 65.52; H, 6.33.
Calc. for C47H54Cl2LiO4Y: C, 66.38; H, 6.36%). FT-Raman
(cmϪ1): 3055m, 2888m, 2875m, 1530w, 1435m, 1326vs, 1003s,
668w, 438w and 286m.
[Li(thf)4][Ln(BH4)2{(C13H8)CPh2(C5H4)}]. Complex 3. To a
suspension of [La(BH4)3(thf)3] (0.85 g, 1.85 mmol) in 15 ml thf
was added dropwise a solution of (C13H8)CPh2(C5H4)Li2 (0.05
M, 37 ml, in thf) with vigorous stirring at Ϫ78 ЊC under argon.
The mixture was slowly warmed to room temperature and
stirred for another 4 h. The precipitate was separated and
resultant clear solution concentrated to 10 ml and slowly
diluted with hexane. Orange crystals of complex 3 were formed
after keeping overnight. (0.35 g, 22%) (Found: C, 64.77; H,
7.09. Calc. For C47H62B2LaLiO4: C, 65.70; H, 7.22%). EI mass
spectrum (70 eV, 50–400 ЊC): m/z 764 (9.10, [M Ϫ LiBH4 Ϫ
thf]ϩ) and 165 (100%). FT-Raman (cmϪ1): 3064m, 3052m,
2984m, 2887m, 2413m, 2218m, 1585w, 1530w, 1436m, 1346m,
1326vs, 1004s, 667w, 437m and 289m.
Conclusion
The synthesis, characterization and structure of several
diphenylmethylene bridged cyclopentadienyl fluorenyl ‘ate’ lan-
thanocene chlorides and tetrahydroborates with Cs symmetry
are reported. The crystal structures demonstrate that these exist
as ate complexes in the solid state.
Experimental
All operations involving organometallics were carried out
under an inert atmosphere of argon using standard Schlenk
techniques. The thf was distilled under argon from sodium–
benzophenone prior to use. Anhydrous lanthanide chlorides17
and lanthanide tetrahydroborate compounds8,18 were prepared
according to the literature and the reactants n-butyllithium and
Complex 4. Analogously to complex 3, 0.89 g [Nd(BH4)3-
(thf)3] (1.92 mmol) afforded 4 as green macrocrystals (0.79 g,
48%) (Found: C, 63.77; H, 6.88. Calc. For C47H62B2LiNdO4:
C, 65.29; H, 7.18%). EI mass spectrum (70 eV, 50–400 ЊC):
m/z 770 (12.03, [M Ϫ LiBH4 Ϫ thf]ϩ) and 165 (100%).
FT-Raman (cmϪ1): 3064m, 3052m, 2984m, 2887m, 2421m,
2221m, 1586w, 1530w, 1436m, 1347m, 1328vs, 1004s, 688w,
437m and 280m.
fluorene were purchased from Aldrich. The compound
14b
(C13H8)CPh2(C5H4)Li2
was synthesized using the literature
method for related compounds. The solvents C6D6 and thf-D8
were degassed and dried over a Na/K alloy. Mass spectra were
recorded on a Hp 5989A spectrometer (50–400 ЊC, 1.3 kV), 1H
NMR on IX-90Q (90 MHz) spectrometers. Elemental analyses
were performed by the Analytical laboratory of the Shanghai
Institute of Organic Chemistry.
Crystallography
Single crystals were sealed in thin-walled glass capillaries under
an atmosphere of argon. Crystal data and experimental details
are given in Table 4. X-Ray diffraction data were collected at
room temperature using the ω–2θ scan technique to a max-
imum 2θ value of 45.0Њ. The intensities of three representative
reflections were measured after every 200. Over the course of
data collection the standards decreased by 2.3%. A linear
correction factor was applied to account for this. The data
were corrected for Lorentz-polarization effects. The structure
were solved by heavy-atom Patterson methods and expanded
using Fourier techniques. The non-hydrogen atoms were
refined anisotropically. All calculations were performed using
TEXSAN.19
Preparations
[Li(thf)4][LnCl2{(C13H8)CPh2(C5H4)}]. Complex 1. A solu-
tion of (C13H8)CPh2(C5H4)Li2 (0.1 M, 42 ml in thf) was added
dropwise to a stirred suspension of LuCl3 (1.58 g, 5.6 mmol) in
20 ml thf at Ϫ78 ЊC under argon. The reaction mixture was
then slowly warmed to room temperature and stirred for 2 d.
The precipitate was filtered off. The filtrate was carefully con-
centrated to a slightly supersaturated solution and allowed to
stand for several days at Ϫ20 ЊC to isolate yellow crystals of
compound 1 (yield: 1.35 g, 63%) (Found: C, 57.40; H, 5.43.
Calc. For C31H22Cl2LiLu: C, 57.50; H, 3.40%). FT-Raman
CCDC reference number 186/1592.
See http://www.rsc.org/suppdata/dt/1999/3283/ for crystallo-
graphic files in .cif format.
3286
J. Chem. Soc., Dalton Trans., 1999, 3283–3287

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9 C. K. Johnson, ORTEP II, Report ORNL-5138, Oak Ridge
National Laboratory, Oak Ridge, TN, 1976.
Acknowledgements
The authors are grateful to the National Nature Science
Foundation of China and Shanghai-Hong Kong Joint Labor-
atory in Chemical Synthesis for their financial support.
10 (a) P. L. Watson, J. F. Whitney and R. L. Harlow, Inorg. Chem.,
1981, 3271; (b) H. Schumann, I. Albrecht, J. Leobel, E. Hahn,
B. Hossain and D. Van der Helm, Organometallics, 1986, 5, 1296;
(c) M. A. Giardello, V. P. Conticello, L. Brard and T. J. Marks,
J. Am. Chem. Soc., 1994, 116, 10241; (d) M. D. Rausch, K. J.
Moriarty, J. L. Atwood, J. A. Weeks, W. E. Hunter and H. G.
Brittain, Organometallics, 1986, 5, 1281.
References
1 W. Kaminsky, K. Kulper, H. H. Brintzinger and F. R. P. Wild,
Angew. Chem., Int. Ed. Engl., 1985, 24, 507.
11 M. F. Lappert, A. Singh, J. L. Atwood, W. E. Hunter and H. M.
Zhang, J. Chem. Soc., Chem. Commun., 1983, 69.
2 H. H. Brintzinger, D. Fishcher, R. Mulhaupt, B. Rieger and
R. M. Waymouth, Angew. Chem., Int. Ed. Engl., 1995, 34, 1143;
M. Bochmann, J. Chem. Soc., Dalton Trans., 1996, 255; A. Razavi
and J. L. Atwood, J. Organomet. Chem., 1993, 459, 117; J. A. Ewen,
R. L. Jones, A. Razavi and J. D. Ferrara, J. Am. Chem. Soc., 1988,
110, 6255.
3 E. B. Coughlin and J. E. Bercaw, J. Am. Chem. Soc., 1992, 114, 7606.
4 H. M. Christoper, L. S. Charlotte and T. J. Marks, Organometallics,
1996, 15, 1765; P. W. Roesky, U. Denninger, C. L. Stern and
T. J. Marks, Organometallics, 1997, 16, 4486; D. Stern, M. Sabat and
T. J. Marks, J. Am. Chem. Soc., 1990, 112, 9558.
5 C. Qian, G. Zou and J. Sun, J. Chem. Soc., Dalton Trans., 1999, 519;
1998, 1607; J. Organomet. Chem., 1998, 566, 21; 1996, 525, 53.
6 (a) M. F. Lappert, A. Singh, J. L. Atwood and W. E. Hunter,
J. Chem. Soc., Chem. Commun., 1983, 206; (b) D. Deng, X. Zheng,
C. Qian, J. Sun and L. Zhang, J. Organomet. Chem., 1994, 466, 95;
(c) T. J. Marks and G. W. Grynkewich, Inorg. Chem.,1976, 15, 1302.
7 T. Arliguie, M. Lance, M. Nierlich and M. Ephritikhine, J. Chem.
Soc., Dalton Trans., 1997, 2501.
12 M. A. Giardello, M. Sabat, A. L. Rheingold and C. L. Stern, J. Am.
Chem. Soc., 1994, 116, 10212.
13 R. E. Shannon, Acta Crystallogr., Sect. A, 1976, 32, 751.
14 (a) A. Razavi and J. L. Atwood, J. Organomet. Chem., 1993, 459,
117; (b) A. Razavi and J. Ferrara, J. Organomet. Chem., 1992, 435,
299; (c) A. Razavi and J. L. Atwood, J. Organomet. Chem., 1996,
520, 115.
15 T. Arliguie, D. Baudry, J. C. Berthet, M. Ephritikhine, M. Nierlich,
C. Lance and J. Viger, J. Chem. Soc., Dalton Trans., 1992, 1019;
P. C. Leverd, T. Arliguie, M. Lance, M. Nierlich, J. Vigner and
M. Ephritikhine, J. Chem. Soc., Dalton Trans., 1994, 501.
16 L. Mao, Q. Shen and S. Jin, Polyhedron, 1994, 13, 1023.
17 J. H. Chapman and L. N. Owen, J. Chem. Soc., 1950, 579.
18 U. Mirsaidov, T. G. Rotenberg and T. N. Dymova, Chem. Abstr.,
1976, 85, 136374; Dokl. Akad. Nauk Tadzh. SSR, 1976, 19, 30.
19 TEXSAN, Structure Analysis Package, Molecular Structure
Corporation, Houston, TX, 1985.
8 S. M. Cendrowski-Guillaume, M. Nierlich, M. Lance and M.
Ephritikhine, Organometallics, 1998, 17, 786.
Paper 9/04223G
J. Chem. Soc., Dalton Trans., 1999, 3283–3287
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