Substituted ring-fused yttrium derivatives - X-ray crystal structures of [(L′YCl2·THF)2LiCl·2THF] and [{L′YCl(OH)}6·2THF] (L′ = 2-phenyl-4,5,6,7,8- hexahydroazulenyl)

Article abstract of DOI:10.1002/ejic.200600399

The reaction of lithium salts of ring-fused ligands (L), where the ring fused to the cyclopentadienyl moiety is a saturated one (six, seven, or eight carbon atoms), with YCl₃ in THF in 2:1 and 1:1 molar ratios affords complexes of formula [L₂YCl]₂ and [(LYCl ₂·THF)₂LiCl·2THF], respectively. Here we report the synthesis, spectroscopic characterization, and X-ray crystal structure of [(L′YCl₂·THF)₂LiCl·2THF] (L′ = 2-phenyl-4,5,6,7,8-hexahydroazulenyl), together with the crystal structure of the hexameric species [{L′YCl(OH)}₆·2THF], which was quite unexpectedly isolated during the attempted crystallization of the latter complex and is probably formed by partial hydrolysis of that complex. The activity of the new complexes towards ethylene and 1-hexene polymerization reactions was also tested. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.

Full text of DOI:10.1002/ejic.200600399

FULL PAPER
DOI: 10.1002/ejic.200600399
Substituted Ring-Fused Yttrium Derivatives – X-ray Crystal Structures of
[(LЈYCl2·THF)2LiCl·2THF] and [{LЈYCl(OH)}6·2THF] (LЈ = 2-Phenyl-
4,5,6,7,8-hexahydroazulenyl)
Gino Paolucci,*[a] Manuela Vignola,[a] Alessandra Zanella,[a] Valerio Bertolasi,[b]
Eleonora Polo,*[c] and Silvana Sostero[c]
Keywords: Yttrium / Fused-ring systems / Olefin polymerization
The reaction of lithium salts of ring-fused ligands (L), where
the ring fused to the cyclopentadienyl moiety is a saturated
one (six, seven, or eight carbon atoms), with YCl3 in THF in
2:1 and 1:1 molar ratios affords complexes of formula
[L2YCl]2 and [(LYCl2·THF)2LiCl·2THF], respectively. Here we
report the synthesis, spectroscopic characterization, and X-
ray crystal structure of [(LЈYCl2·THF)2LiCl·2THF] (LЈ = 2-
phenyl-4,5,6,7,8-hexahydroazulenyl), together with the crys-
tal structure of the hexameric species [{LЈYCl(OH)}6·2THF],
which was quite unexpectedly isolated during the attempted
crystallization of the latter complex and is probably formed
by partial hydrolysis of that complex. The activity of the new
complexes towards ethylene and 1-hexene polymerization
reactions was also tested.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2006)
pentadienyl ligands provided with a more versatile structure
and also capable of imparting higher stability and better
solubility in most common organic solvents. In the frame-
work of our research for metallocenes suitable for applica-
tion in homogeneous catalysis, we have recently[8] synthe-
sized several froup 4 ring-fused metallocenes where the ring
(six, seven, or eight carbon atoms) fused to the cyclopen-
tadienyl moiety is a saturated one. Besides their higher solu-
bility, stability, and resistance to hydrolysis in comparison
with the corresponding unsaturated counterparts, these
complexes proved to be interesting polymerization cata-
lysts,[9] since their particular structure introduces a confor-
mational flexibility that can be finely tuned by varying the
size of the cycloalkyl-ring and by introducing different sub-
stituents on the cyclopentadienyl ring. Here, we report the
reactions of some ligands of this family with yttrium tri-
chloride in 1:1 and 2:1 molar ratios as a test for lanthanides
to check if they can produce more stable and soluble com-
plexes for catalytic applications.
Introduction
The chemistry of group 3 organometallics has undergone
a spectacular growth in the past two decades.[1] Besides
their activity as catalysts and reagents for a number of reac-
tions,[2] they are also reckoned to be excellent models[3] and
very active catalysts for Ziegler–Natta polymerizations of
olefins, often without the aid of activators or co-catalysts.
Lanthanide chemistry has been dominated mainly by cy-
clopentadienyl complexes[4] because this family of ligands
allows a wide range of modifications of the environment at
the metal center through simple variation of the substitu-
tion pattern. Despite the interesting results thus far ob-
tained, their high sensitivity to air and moisture, polar sol-
vents,[5] and reagents[5,6] makes their application on an in-
dustrial scale still quite difficult. Furthermore, lanthanides
with unsubstituted cyclopentadienyl ligands are almost in-
soluble in hydrocarbon solvents and usually show low ac-
tivity.[7] Due to the delicate balance required in the ligand
substitution pattern, it is advisable to find a family of cyclo-
[a] Dipartimento di Chimica, Università Ca’Foscari di Venezia,
Dorsoduro 2137, 30123 Venezia, Italy
E-mail: paolucci@unive.it
Results and Discussion
[b] Centro di Strutturistica Diffrattometrica and Dipartimento di
Chimica, Università di Ferrara,
Synthesis and Characterization of Yttrium Complexes
44100 Ferrara, Italy
The lithium salts (C6CpMe)Li (1; HL = 2-methyl-
4,5,6,7-tetrahydro-1H-indene), (C7CpMe)Li (2; HL = 2-
methyl-1,4,5,6,7,8-hexahydroazulene, and (C8CpMe)Li (3;
HL = 2-methyl-4,5,6,7,8,9-hexahydro-1H-cyclopenta[8]an-
nulene, prepared according to the literature procedures,[9a]
were treated with YCl3 in a 2:1 molar ratio to afford the
corresponding complexes [L2YCl]2 with L = C6CpMe (4),
Fax: +39-053-224-0709
E-mail: m38@unife.it
[c] C.N.R.I.S.O.F., sez. Ferrara, Dipartimento di Chimica, Uni-
versità di Ferrara,
Ferrara, Italy
Fax: +39-053-224-0709
E-mail: tr3@unife.it
Supporting information for this article is available on the
WWW under http://www.eurjic.org or from the author.
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Substituted Ring-Fused Yttrium Derivatives
FULL PAPER
C7CpMe (5), and C8CpMe (6), and in a 1:1 ratio to give drous Nujol allowed X-ray data collection at 150 K; this
the complexes [(LYCl2·THF)2LiCl·2THF] with
C7CpMe (7) and C8CpMe (8); see Scheme 1.
L
=
confirmed the analytical and NMR spectroscopic data,
which correspond to a complex of formula [(LЈYCl2·
THF)2LiCl·2THF] (LЈ = C7CpPh; Figure 1).
Scheme 1. Synthesis of the 2-methyl-substituted complexes.
The resulting complexes, which were isolated as dusty so-
lids by precipitation with n-hexane from toluene or CH2Cl2
solutions, are also completely soluble in diethyl ether and
THF. Analytical (elemental analyses and MS data) and
NMR (1H and 13C; assignments by HMQC and HMBC
experiments) data were consistent with the given formula-
tions.
Figure 1. ORTEP[10] view of complex 11 displaying the thermal el-
lipsoids at 30% probability. The hydrogen atoms have been omitted
for sake of clarity.
Crystal Structures
Crystals of complexes 4, 6, 7, and 8 were obtained by
slow evaporation of concentrated CH2Cl2 solutions, but,
despite repeated attempts, they were not suitable for X-ray
analysis. This difficulty in obtaining ordered structures is
probably due both to the flexibility of the saturated ring
and to the small size of the methyl group. Only complex 5
gave crystals suitable for X-ray diffraction, but they did not
withstand the treatment (Fomblin F06206R or dehydrated
Nujol) necessary to protect them from air and moisture
during X-ray data acquisition.
Since the reactivity, stability, and solubility of lanthanide
compounds are highly dependent on the steric hindrance of
the ligand preventing oligomer formation, we decided to
substitute the methyl group in the 2-position of the ligands
for a phenyl group in order to obtain more ordered crystals.
We chose the ligand with a saturated ring of seven carbon
atoms since it was the only one that gave acceptable crystals
for 5 and 7. Treatment of lithium 2-phenyl-1,4,5,6,7,8-hexa-
hydroazulenyl (LЈ, 9)[9b] with YCl3 in a 2:1 or 1:1 molar
ratio, afforded complexes [(LЈ2YCl)2] (10) and
[(LЈYCl2·THF)2LiCl·2THF] (11), respectively (Scheme 2).
The structure (Figure 1, and Tables S1 and S2 in the Sup-
porting Information) consists of a trimetallic complex
where two atoms of yttrium and one atom of lithium, in a
distorted octahedral coordination, are bridged by three µ-
Cl (Cl1, Cl2, and Cl5) and two µ3-Cl (Cl3 and Cl4) anions.
Each Y atom is coordinated to four chloride ions, an η5-
cyclopentadienyl ring of the 2-phenyl-1,4,5,6,7,8-hexahy-
droazulenyl ligand, and a molecule of THF, while the lith-
ium cation is coordinated to four Cl ions (Cl1, Cl3, Cl4,
and Cl5) and two molecules of THF. The six Y–C1 bonds
involved in the formation of Y–Cl–Y bridges display dis-
tances in the range 2.677(1)–2.860(1) Å (2.77 Å on average),
and are slightly longer than those observed in di-
meric bis[(µ-Cl)YIII(cyclopentadienyl)] complexes (2.66–
2.70 Å).[11–13] This Y–Cl lengthening can be justified by the
presence of a µ-Cl bridge between yttrium atoms and two
µ3-Cl bridges which involve all three metal centers. The re-
maining µ-Cl1 and µ-Cl5 chlorides connecting yttrium
atoms with lithium display shorter Y–Cl distances of
2.607(2) and 2.627(1) Å, in agreement with those found in
the range 2.62–2.65 Å in similar Y–Cl–Li fragments.[14,15]
During our attempts to finding the appropriate crystalli-
zation solvents for complex 11, in one crop we isolated se-
veral crystals stable to Fomblin treatment which allowed
crystal data collection. Quite unexpectedly, they turned out
to be the partial hydrolysis product of 11, most probably
caused by slight traces of water in the crystallization sol-
vent. The results of the fast X-ray data collection at 120 K
Scheme 2. Synthesis of the 2-phenyl-substituted complexes.
Crystals suitable for X-ray diffractometry studies were revealed the structure of an organometallic yttrium cluster,
obtained only in the case of complex 11. While attempts to namely [{LЈYCl(OH)}6·2THF] (12; Figure 2 and Tables S3
protect the crystals with Fomblin failed, the use of anhy- and S4 in the Supporting Information). It is well known
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G. Paolucci, M. Vignola, A. Zanella, V. Bertolasi, E. Polo, S. Sostero
FULL PAPER
that hydrolysis and oxidation reactions are a common mode
of decomposition for organometallic complexes of yttrium
and the f elements, giving in most cases organometallic spe-
cies containing M–OH or M–O–O–M bonds.[16–18]
Figure 3. Diagram of the metal, halogen, and hydroxy framework
of complex 12, including the coordinated THF molecules.
Figure 2. ORTEP view of complex 12 displaying the thermal ellip-
soids at 30% probability. The hydrogen atoms have been omitted
for sake of clarity.
Polymerization Studies
We have examined the activity of the new yttrium com-
plexes, with MAO as co-catalyst, as a preliminary test for
The 1H NMR spectrum of crystals of complex 12 is quite their polymerization activity. It is known[2] that organolan-
similar to that of 11 except for the presence of a very broad thanide complexes often do not require a co-catalyst or an
singlet at δ = 2.73 ppm that can be attributed to the OH activator to show high activity, but they must be previously
group. The IR spectrum in CH2Cl2 solution shows an OH converted into the corresponding sterically demanding alkyl
stretch at 3540 cm1.
derivatives [(trimethylsilyl)methyl or bis(trimethylsilyl)-
Complex 12 is a hexamer where two trimetallic clusters methyl], to prevent β-alkyl elimination, and as intermedi-
of yttrium atoms are held together, around a center of sym- ates to the more unstable, but much more active, hydrides.
metry, by two µ-Cl3 chlorides between Y1 and Y3 (Fig-
The bis(cyclopentadienyl) complexes 4, 5, 6, and 10 did
ure 3). In each trimer the yttrium atoms are surrounded by not show any activity towards ethene polymerization, while
an η5-bonded cyclopentadienyl ring belonging to a 2- the mono(cyclopentadienyl) complexes 7 and 11, which
phenyl-1,4,5,6,7,8-hexahydroazulenyl ligand and bridged by have a more open coordination sphere around the metal
chloride and hydroxy groups. In particular, the three Cl1, center, show a moderate activity (Table 1). This result can
Cl2, and O3H anions span the three edges of the triangles be interpreted by taking into account the fact that only a
formed with the Y atoms, while the µ3-O1H and µ3-O2H limited number of mono(cyclopentadienyl) half-sandwich
hydroxy groups triply bridge above and below the triangle rare-earth complexes of the type [(η5-C5R5)LnX2(L)n] have
formed by the yttrium atoms. The sixfold coordination been synthesized, and their catalytic performance is often
around Y2 is completed by the oxygen atom of a THF hampered by “ate complex” formation with concomitant
molecule.
alkali metal salt incorporation.[24] We also noticed some dif-
Accordingly, the overall geometry about each yttrium ferences between the polymers obtained with the methyl-
atom can be described as a distorted octahedral coordina- substituted (7) and phenyl-substituted (11) derivatives.
tion. The Y–(µ-Cl) distances (2.66–2.74 Å) are in agreement While with the methyl-substituted complex 7, after the us-
with those observed in dimeric bis[(µ-Cl)YIII(cyclopentadi- ual work-up, a single fraction of highly linear polyethylene
enyl)] complexes. Furthermore, as observed in other com- was produced (single peak at δ = 27.7 ppm in the 13C NMR
pounds,[16–19] the Y–(µ-OH) distances of 2.230(6) and spectrum), with the phenyl-substituted complex 11 the yield
2.216(4) Å for Y1–O3 and Y2–O3, respectively, are shorter was almost twice as high but the solid consisted of two frac-
than those of Y–(µ3-OH), which are in the range 2.34– tions, the first (43%) of which is similar to the polymer
2.43 Å. In both complexes the Y–Cp(cyclopentadienyl isolated with the catalyst 7 and the second (57%) of which
centroid) bond length (2.37–2.40 Å) and the Y–O(THF) contains a mixture of oligomers. Apparently this different
distance of 2.338(6) Å are in accordance with the respective behavior can be attributed to the influence of the substitu-
values observed in other cyclopentadienylyttrium deriva- ent in the ancillary ligand. It is likely that the methyl group,
tives.[20–23]
which exerts a symmetrical steric hindrance around the
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Substituted Ring-Fused Yttrium Derivatives
FULL PAPER
none ketyl; CH2Cl2, CD2Cl2, and CDCl3 over CaH2; C6D5N over
KOH). YCl3 (Aldrich) was used as received. Nujol (Aldrich) was
degassed and dehydrated by reflux over potassium. Fomblin
(ABCR) F06206R, viscosity 1600cSt, was degassed prior to use.
The ligands C6CpMeH,[8] C6CpMeLi (1),[8] C7CpMeH,[8]
C8CpMeH,[8] and C7CpPhH[9a] were prepared according to litera-
ture methods. Microanalyses were performed at the Istituto di Chi-
mica Inorganica e delle Superfici, CNR, Padova. The Li contents
of the complexes were determined by ICP using an ICP-MS Agilent
7500 apparatus. Mass spectra were recorded with a Finnigan Trace
MS equipped with a probe for the direct introduction of the sample
metal center, produces a more homogeneous material than
the phenyl with its different space occupancy. We also tried
the polymerization of a more sterically demanding mono-
mer, 1-hexene, but we could not get any polymer. In struc-
turally similar achiral lanthanocenes,[2e,25] which are also in-
active towards 1-alkene polymerization, this negative result
has been attributed to the formation of stable η3-allyl type
complexes.[26]
Table 1. Results of ethane and 1-hexene polymerizations.
Activity[a]
Oligomers [%]
1
(EI = 70 eV, Tprobe = 120–150 °C). H and 13C NMR spectra were
Complex
Monomer
obtained for CDCl3 or CD2Cl2 solutions with a Bruker AMX 300
spectrometer operating at 300 and 100.61 MHz, respectively. 2D-
Heterocorrelated COSY experiments (HMQC and HMBC) al-
4, 5, 6, 10
ethene[b]
–
–
7
57
–
–
7
ethene[b]
820
1650
–
11
7
11
ethene[b]
1
1-hexene[c]
1-hexene[c]
lowed the identification of all H and 13C resonances.
–
Lithium Salts of the Ligands. General Synthetic Procedure: The
starting diene (14 mmol) was suspended in n-hexane at –80 °C. n-
Butyllithium (14 mmol) was then added dropwise, whilst stirring,
and the solution was slowly allowed to reach room temperature
(about 4 h) and stirred overnight. The lithium salt that separated
from the solution was isolated by centrifugation, washed several
times with n-hexane, and dried under vacuum to give a dusty solid.
[a] gPol(mmoly hatm)–1. [b] Reaction conditions: toluene: 100 mL,
[Y] = 8×10–6 , [MAO]/[Y] = 1100, trxn = 24 h, room temp. [c]
Reaction conditions: toluene: 100 mL, [Y] = 8×10–6 , [MAO]/[Y]
= 1875, trxn = 24 h, room temp.
Conclusions
2-Methyl-1,4,5,6,7,8-hexahydroazulenyllithium (2): White solid.
Yield: 1.94 g (90%). H NMR ([D5]pyridine): δ = 1.73–1.94 (m, 6
1
Novel unbridged bicyclic yttrium complexes containing
six-, seven-, and eight-membered saturated rings fused to a
cyclopentadienyl moiety substituted in position 2 (CH3, Ph)
have been synthesized with 2:1 and 1:1 ligand/metal ratios,
and fully characterized. Unlike their analogous cyclopen-
tadienyl derivatives, these complexes are very soluble in
most common organic solvents but are highly sensitive to
air and moisture. The crystal structure of complex 11 shows
its dimeric nature, thus confirming that the high coordina-
tive unsaturation of the monomer in the absence of high
steric hindrance favors the formation of dimeric yttrium
species. Quite unexpectedly, we have been able to isolate
and fully characterize the hexameric yttrium organometallic
cluster 12, which is probably formed by the reaction of 11
with traces of water in the crystallization solvent. The yttrio-
cenes 4, 5, 6, and 10, in combination with MAO as co-
catalyst, are inactive in the polymerization of ethylene and
1-hexene, while complexes 7 and 11 show a low reactivity
towards ethene polymerization and are also inactive
towards 1-hexene. These unsatisfactory results can be at-
tributed to the probably dimeric nature of the complexes,
which is maintained after MAO activation, thus preventing
access of the olefin to the reactive center due to steric hin-
drance. Further studies are necessary to modify the chloro
complexes (i.e., by substitution with bulky alkyl groups) in
order to produce monomeric yttrium species, which should
be more efficient polymerization catalysts.
H, C-CH2-CH2-), 2.43 (s, 3 H, CH3), 2.85 (br. s, 4 H, -C-CH2-
CH2-), 5.86 (s, 2 H, -CH-,Cp) ppm.
2-Methyl-4,5,6,7,8,9-hexahydro-1H-cyclopenta[8]annulenyllithium
1
(3): White solid. Yield: 2.22 g (88%). H NMR ([D5]pyridine): δ =
1.57–1.74 (m, 8 H, C-CH-CH2-), 2.41 (s, 3 H, CH3), 2.68–2.74 (m,
4 H, -C-CH2-CH2-), 5.86 (s, 2 H, -CH-, Cp) ppm.
2-Phenyl-1,4,5,6,7,8-hexahydroazulenyllithium (9): Pink-white solid.
1
Yield 1.82 g (60%). H NMR ([D5]pyridine): δ = 1.47–1.65 (m, 6
H, C-CH-CH2-), 2.48 (m, 4 H, -C-CH2-CH2-), 6.11 (s, 2 H, -CH-,
3
3
Cp), 6.50 (t, JH,H = 7.7 Hz, 1 H, meta-C5H6), 6.90 (t, JH,H
=
7.7 Hz, 2 H, para-C5H6), 7.42 (d, 3JH,H = 7.6 Hz, 2 H, ortho-C5H6)
ppm.
Yttrium Complexes. General Synthetic Procedure: YCl3 (1.0 mmol)
was dissolved in warm THF (30 mL) and cooled to room tempera-
ture. A solution of the lithium salt (2.0 or 1.0 mmol) dissolved in
THF (20 mL) was then added with vigorous stirring at room tem-
perature, and the reaction mixture stirred overnight. The solvent
was then removed under reduced pressure, the residue washed with
dichloromethane (3×10 mL), and separated from LiCl, when nec-
essary, by centrifugation. The yellow solution was concentrated (to
about 10 mL) and left at –25 °C for several days to give microcrys-
tals.
Bis[(µ-chloro){bis[η5-(2-methyl-4,5,6,7-tetrahydro-1H-indenyl)]-
yttrium}] (4): Yellow solid. Yield: 0.508 g (65 %). C40H52Cl2Y2
(781.57): calcd. C 61.47, H 6.71, Cl 9.07; found C 61.05, H 6.95,
1
Cl 8.90. H NMR (CDCl3): δ = 1.65–1.80 (m, 8 H, C-CH2-CH2-),
2.05 (s, 6 H, CH3), 2.50–2.90 (m, 8 H, -C-CH2-CH2-), 5.90 (s, 4
H, -CH-, Cp) ppm. 13C NMR (CDCl3): δ = 14.9 (CH3), 29.9 (-C-
CH2-CH2-), 33.1(-C-CH2-CH2-), 114.6 (-CH, Cp), 125.7 (-C-CH3),
132.8 (-CH2-C=CH-, Cp) ppm. MS (Tprobe = 120 °C): m/z (%) 766
(18) [M+· – CH3]+, 751 (22) [M+· – 2CH3]+, 746 (12) [M+· – Cl]+,
731 (10) [M+· – CH3 – Cl]+.
Experimental Section
General procedures: All manipulations were carried out under an
oxygen- and moisture-free atmosphere in a Braun MB 200 GII
glove box. All solvents were thoroughly deoxygenated and dehy-
drated under argon by refluxing and distillation over a suitable
drying agent (n-hexane, toluene, and THF over Na or K/benzophe-
Bis[(µ-chloro){bis[η5-(2-methyl-1,4,5,6,7,8-hexahydroazulenyl)]-
yttrium}] (5): Yellow solid. Yield: 0.611 g (73 %). C44H60Cl2Y2
(837.68): calcd. C 63.09, H 7.22, Cl 8.46; found C 62.75, H 6.95,
1
Cl 8.65. H NMR (CDCl3): δ = 1.35–1.70 (m, 8 H, C-CH2-CH2-
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FULL PAPER
CH2-), 1.70–1.95 (m, 4 H, C-CH2-CH2-CH2-), 2.08 (s, 6 H, CH3), Crystals suitable for X-ray analysis were obtained from a very con-
2.50–2.90 (m, 8 H, -C-CH2-CH2-CH2-), 5.95 (s, 4 H, -CH-, Cp) centrated CH2Cl2 solution after four days at –26 °C.
ppm. 13C NMR (CDCl3): δ = 14.9 (CH3), 29.9 (-C-CH2-CH2-
CH2-), 31.6 (-C-CH2-CH2-CH2-), 33.2 (C-CH2-CH2-CH2), 114.4
(-CH, Cp), 120.3 (-C-CH3), 129.8 (-CH2-C=CH-, Cp) ppm. MS
Complex 12: Yellow solid, C104H108Cl6O8Y6 (2232.12): calcd. C
55.96, H 5.73, Cl 9.53; found C 55.80, H 5.60, Cl 9.40. IR
1
(CH Cl ): ν = 3540 cm–1. H NMR (CD Cl ): δ = 1.55–1.71 (m, 8
˜
2
2
2
2
(Tprobe = 120 °C): m/z (%) 837 (1) [M]+·, 822 (21) [M+· – CH3]+, 807
(25) [M+· – 2CH3]+, 802 (15) [M+· – Cl]+, 690 (42) [C33H45Cl2Y2]+,
403 (44) [C21H27ClY]+, 388 (100) [C20H24ClY]+, 368 (37)
[C21H27Y]+.
H, C-CH2-CH2-CH2-), 1.71–1.83 (m, 4 H, C-CH2-CH2-CH2-), 1.89
(br. s, 2.7 H, THF), 2.37–2.55 (m, 8 H, -C-CH2-CH2-CH2-), 2.73
(br. s, 1 H, OH), 3.97 (br. s, 2.7 H, THF), 6.66 (s, 4 H, -CH-, Cp),
3
7.12 (t, 3JH,H = 7.0 Hz, 2 H, para-C5H6), 7.27 (t, JH,H = 7.0 Hz, 4
3
Bis[(µ-chloro){bis[η5-(2-methyl-4,5,6,7,8,9-hexahydro-1H-cyclo-
penta[8]annulenyl)]yttrium}] (6): Yellow solid. Yield: 0.590 g (66%).
C48H68Cl2Y2 (893.78): calcd. C 64.50, H 7.67, Cl 7.93; found C
64.15, H 7.25, Cl 7.80. 1H NMR (CDCl3): δ = 1.10–1.25 (m, 12
H, -CH2-), 1.25–1.50 (m, 4 H, -CH2-), 2.00 (s, 6 H, CH3), 2.30–
2.45 (m, 4 H, -C-CH2-CH2-), 2.55–2.75 (m, 4 H, -C-CH2-CH2-),
5.95 (s, 4 H, s, 4 H, -CH-, Cp) ppm. 13C NMR (CDCl3): δ = 14.9
(CH3), 26.3 (C-CH2-CH2–CH2-), 27.4 (-C-CH2-CH2-CH2-), 33.4
(C-CH2-CH2-CH2), 112.3 (-CH, Cp), 122.0 (-C-CH3), 128.3 (-CH2-
C=CH-, Cp) ppm. MS (Tprobe = 10 °C): 893 (3) [M]+·, 878 (27)
[M+· – CH3]+, 863 (31) [M+· – 2CH3]+, 858 (15) [M+· – Cl]+, 446
(8) [C24H34ClY]+, 431 (100) [C23H31ClY]+, 416 (65) [C22H28ClY]+,
396 (37) [C23H31Y]+.
H, meta-C5H6), 7.44 (d, JH,H = 7.0 Hz, 4 H, ortho-C5H6) ppm.
X-ray Crystallographic Structure Determinations for 11 and 12: The
crystal data for compounds 11 and 12 (Table 2) were collected at
120 and 150 K, respectively, using a Nonius Kappa CCD dif-
fractometer with graphite-monochromated Mo-Kα radiation. The
data sets were integrated with the Denzo-SMN package[27] and cor-
rected for Lorentz, polarization, and absorption (SORTAV[28]) ef-
fects. The structures were solved by direct methods (SIR97[29]) and
refined using full-matrix least-squares with all non-hydrogen atoms
anisotropic and hydrogens included at calculated positions as ri-
ding on their carrier atoms. All calculations were performed using
SHELXL97[30] and PARST[31] implemented in WINGX[32] system
of programs.
Complex 7: Yellowish solid. Yield: 0.803 g (85 %). C38H62Cl5-
Table 2. Crystal data for complexes 11 and 12.
LiO4Y2 (944.92): calcd. C 48.30, H 6.61, Cl 18.76, Li 0.73; found
1
C 47.95, H 6.55, Cl 18.45, Li 0.80. H NMR (CDCl3): δ = 1.25–
Compound
11
12
1.95 (m, 12 H, -CH2-), 1.90 (br. s, 16 H, THF), 2.00 (s, 6 H, CH3),
2.45–2.80 (m, 8 H, -C-CH2-CH2-), 3.80 (br. s, 16 H, THF), 5.95 (s,
4 H, -CH-, Cp) ppm.
Formula
MW
Space group
Crystal system
a [Å]
b [Å]
c [Å]
α [°]
β [°]
C48H66Cl5LiO4Y2
C104H108Cl6O8Y6
2520.56
P1
triclinic
14.0415(3)
14.4971(3)
15.4855(5)
76.886(1)
86.128(1)
65.722(2)
150
1
1.496
1286
33.940
42244
1069.02
P212121
orthorhombic
11.6874(3)
19.9579(5)
21.3214(4)
90
90
90
120
4
¯
Complex 8: Yellow solid. Yield: 0.807 g (83%). C40H66Cl5O4LiY2
(972.96): calcd. C 49.38, H 6.84, Cl 18.22, Li 0.71; found C 49.15,
1
H 6.75, Cl 18.45, Li 0.80. H NMR (CDCl3): δ = 1.10–1.85 (m, 16
H, -CH2-), 1.98 (br. s, 16 H, THF), 2.05 (s, 6 H, CH3), 2.10–2.65
(m, 8 H, -C-CH2-CH2-), 4.04 (br. s, 16 H, THF), 5.72 (s, 4 H,
-CH-, Cp) ppm. 13C NMR (CDCl3): δ = 16.28 (CH3), 25.81 (THF),
26.47 (-C-CH2-CH2-CH2-), 27.71 (-C-CH2-CH2-CH2-), 33.33 (C-
CH2-CH2-CH2-), 71.02 (THF), 114.16 (-CH, Cp), 123.0 (-C–CH3),
129.91 (-CH2-C=CH-, Cp) ppm.
γ [°]
T [K]
Z
Dc [gcm–3
F(000)
]
1.428
2200
26.313
Bis[(µ-chloro){bis[η5-(2-phenyl-1,4,5,6,7,8-hexahydroazulenyl)]-
yttrium}] (10): Deep-yellow solid. Yield: 0.847 g (78 %).
C64H68Cl2Y2 (1085.9): calcd. C 70.78, H 6.31, Cl 6.53; found C
µ(Mo-Kα) [cm–1
]
Measured reflections 29098
Unique reflections
Rint
9657
0.101
12718
0.050
9484
4.00–27.50
1
70.45, H 6.15, Cl 6.75. H NMR (CD2Cl2): δ = 1.12–2.10 (m, 12
Obs. reflns [I Ն 2σ(I)] 7677
H, -CH2-), 2.25–2.85 (m, 8 H, -C-CH2-CH2-CH2-), 6.14 (s, 4 H,
-CH-, Cp), 7.12 (t, 3JH,H = 7.23 Hz, 2 H, para-C5H6), 7.33 (t, 3JH,H
= 7.62 Hz, 4 H, 4 H, meta-C5H6), 7.46 (d, 3JH,H = 7.23, 4 H, ortho-
C5H6) ppm. MS (Tprobe = 120 °C): m/z (%) 1085 (1) [M]+·, 877 (44)
[C48H51Cl2Y2]+, 667 (2) [C32H34Cl2Y2]+, 543 (1) [C32H34ClY]+, 528
(100) [C31H31ClY]+, 493 (28) [C31H31Y]+, 298 (1) [C16H16Y]+, 210
(20) [C16H18]+.
Θmin, Θmax [°]
hkl ranges
2.85–26.00
–13,14; –24,24; –26,26 –18,18; –16,18; –19,20
R(F2)(obs. reflns.)
wR(F2) (all reflns.)
No. variables
0.0537
0.0961
541
1.054
–0.686, 0.379
0.0701
0.1781
625
1.218
–0.750, 1.180
Goodness of fit
ρmin, ρmax [eÅ–3
]
Complex 11: Deep-yellow solid. Yield: 0.823 g (77 %).
C48H66Cl5LiO4Y2 (1069.05): calcd. C 53.93, H 6.22, Cl 16.58, Li
0.65; found C 54.10, H 6.05, Cl 16.80, Li 0.70. 1H NMR (CD2Cl2):
δ = 1.65 (m, 8 H, C-CH2-CH2-CH2-), 1.78 (m, 4 H, C-CH2-CH2-
CH2-), 1.89 (br. s, 16 H, THF), 2.40–2.53 (m, 8 H, -C-CH2-CH2-
CH2-), 3.99 (br. s, 16 H, THF), 6.65 (s, 4 H, -CH-, Cp), 7.11 (t,
CCDC-297382 (for 11) and -297383 (for 12) contain the supple-
mentary crystallographic data for this paper. These data can be
obtained free of charge from The Cambridge Crystallographic
Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
Supporting Information (see also the footnote on the first page of
this article): Selected interatomic distances and angles are given in
Tables S1–S4.
3
3JH,H = 7.3 Hz, 2 H, para-C5H6), 7.27 (t, JH,H = 7.3 Hz, 4 H,
3
meta-C5H6), 7.43 (d, JH,H = 7.3 Hz, 4 H, ortho-C5H6) ppm. 13C
NMR (CD2Cl2): δ = 25.7 (THF), 28.3 (-C-CH2-CH2-CH2-), 28.4
(-C-CH2-CH2-CH2-), 30.1 (-C-CH2-CH2-CH2-), 30.7 (-C-CH2-CH2- General Polymerization Conditions: All manipulations of air- and/
CH2-), 31.9 (-C-CH2-CH2-CH2-), 70.4 (THF), 124.7 (ortho-C5H6),
126.1 (para-C5H6), 128.7 (meta-C5H6), 133.0 (-CH, Cp), 142.0
or moisture-sensitive materials were carried out under inert atmo-
sphere using either a dual vacuum/nitrogen line and standard
(ipso-C5H6), 142.8 (-C–C5H6), 143.6 (-CH2-C=CH-, Cp) ppm. Schlenk techniques or in a dry-box under nitrogen atmosphere
4108 Eur. J. Inorg. Chem. 2006, 4104–4110
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© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

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The authors warmly thank Dr. F. Forlini of ISMAC-C.N.R. (Mil-
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Published Online: August 11, 2006
4110
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Eur. J. Inorg. Chem. 2006, 4104–4110