Reactivity of rare-earth metal complexes stabilized by an anilido-phosphinimine ligand

Article abstract of DOI:10.1021/om801004r

Treatment of anilido-phosphinimine-ligated yttrium mono(alkyl) complex la, LY(CH₂Si(CH₃)₃)(THF) (L = o-(2,6-C ₆H₃Pr₂)NC₆H₄P(C ₆H₄)(C₆H

Full text of DOI:10.1021/om801004r

Organometallics 2009, 28, 1453–1460
1453
Reactivity of Rare-Earth Metal Complexes Stabilized by an
Anilido-Phosphinimine Ligand
Bo Liu,†,‡ Xinli Liu,† Dongmei Cui,*,†,§ and Li Liu§
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry,
Chinese Academy of Sciences, Changchun 130022, People’s Republic of China, Graduate School of the
Chinese Academy of Sciences, Beijing 100039, People’s Republic of China, and Ministry-of-Education Key
Laboratory for the Synthesis and Application of Organic Functional Molecules,
Hubei UniVersity, People’s Republic of China
ReceiVed October 18, 2008
Treatment of anilido-phosphinimine-ligated yttrium mono(alkyl) complex 1a, LY(CH2Si(CH3)3)(THF)
i
(L ) o-(2,6-C6H3 Pr2)NC6H4P(C6H4)(C6H5)N(2,4,6-C6H2Me3)), with 2 equiv of phenylsilane in DME
afforded methoxy-bridged complex 2, [LY(µ-OCH3)]2, via the corresponding hydrido intermediate. When
excess isoprene was added to the mixture of 1a and phenylsilane, a η3-isopentene product, 3,
LY(CH2C(CH3)dCHCH3)(THF), was isolated. A lutetium chloride, LLuCl(DME) (4), was generated
through the reaction of lutetium mono(alkyl) complex 1b, LLu(CH2Si(CH3)3)(THF), with [Ph3C]-
[B(C6F5)4] · LiCl accompanied by the formation of [Li(DME)3]+[B(C6F5)4]-. Metathesis reaction of 1b
with excess AlMe3 at room temperature gave a methyl-terminated counterpart, 5, LLu(CH3)(THF)2. In
all these reactions, the Ln-Cphenyl bonds of complexes 1 remained untouched. However, protonolysis of
complex 1b with 2 equiv of phenylacetylene in DME provided a lutetium bis(acetylide),
LHLu(Ct CPh)2(DME) (6), and the linkage of the Ln-Cphenyl bond was cleaved, indicating that the
activated C-H bond was recovered.
of rare-earth metal complexes bearing the anilido-phosphinimine
and amino-phosphine ligands, which have shown unique C-H
activation and unprecedented catalysis on the regioselective
cycloaddition of organic azides and aromatic alkynes.5 These
results intrigued us to apply these phosphide ligands to stabilize
the rare-earth metal hydrido and cationic species that have been
single-component catalysts or precursors for the polymerizations
of olefins and dienes.6 Owing to the hard Lewis acidity and
large ionic radii of Ln3+ ions, rare-earth metal cations and
hydrides have been dominated by cyclopentadienyl,7 heterocy-
Introduction
Ligand design is becoming an increasingly important part of
organometallic chemistry due to the subtle control that ligands
exert on the metal center. To date, many cyclopentadienyl1 and
non-cyclopentadienyl ligands2 have been applied to stabilize
group 3 metal complexes. The recent surge of activity in the
use of phosphinimine donors in organotransition metal chemistry
directed a new path for rare-earth organometallic chemistry.3
By introducing “large” and “soft” phosporus donor, phosphorus
chelating complexes were expected to possess the potential for
catalytic activity toward nonpolar monomers4 and new stoichio-
metric chemistry. Our group has successfully isolated a series
(5) (a) Liu, B.; Cui, D.; Ma, J.; Chen, X.; Jing, X. Chem.-Eur. J. 2007,
13, 834. (b) Liu, B.; Yang, Y.; Cui, D.; Tang, T.; Chen, X.; Jing, X. Dalton
Trans. 2007, 4252. (c) Liu, B.; Cui, D. Dalton Trans. 2009, 550.
(6) (a) Trifonov, A. A.; Skvortsov, G. G.; Lyubov, D. M.; Skorodumova,
N. A.; Fukin, G. K.; Baranov, E. V.; Glushakova, V. N. Chem.-Eur. J.
2006, 12, 5320. (b) Trifonov, A. A.; Fedorova, E. A.; Fukin, G. K.;
Bochkarev, M. N. Eur. J. Inorg. Chem. 2004, 4396. (c) Yu, N.; Nishiura,
M.; Li, X.; Xi, Z.; Hou, Z. Chem. Asian J. 2008, 3, 1406. (d) Zhang, L.;
Nishiura, M.; Yuki, M.; Luo, Y.; Hou, Z. Angew. Chem., Int. Ed. 2008, 47,
2642. (e) Arndt, S.; Beckerle, K.; Zeimentz, P. M.; Spaniol, T. P.; Okuda,
J. Angew. Chem., Int. Ed. 2005, 44, 7473. (f) Zimmermann, M.; Tornroos,
K. W.; Anwander, R. Angew. Chem., Int. Ed. 2008, 47, 775. (g) Wang, B.;
Cui, D.; Lv, K. Macromolecular 2008, 41, 1983.
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Dalton Trans. 2005, 1387. (d) Hou, Z.; Zhang, Y.; Tardif, O.; Wakatsuki,
Y. J. Am. Chem. Soc. 2001, 123, 9216. (e) Song, X.; Thornton-Pett, M.;
Bochmann, M. Organometallics 1998, 17, 1004. (f) Bouwkamp, M. W.;
Budzelaar, P. H. M.; Gercama, J.; Del Hierro Morales, I.; de Wolf, J.;
Meetsma, A.; Troyanov, S. I.; Teuben, J. H.; Hessen, B. J. Am. Chem. Soc.
2005, 127, 14310. (g) Evans, W. J.; Chamberlain, L. R.; Ulibarri, T. A.;
Ziller, J. W. J. Am. Chem. Soc. 1988, 110, 6423. (h) Kaita, S.; Hou, Z.;
Wakatsuki, Y. Macromolecules 2001, 34, 1539. (i) Evans, W. J.; Ulibarri,
T. A. W.; Ziller, J. J. Am. Chem. Soc. 1990, 112, 2314. (j) Christopher,
J. N.; Squire, K. R.; Canich, J. A. M.; Shaffer, T. D. (Exxon Chemical
Patents Inc., USA). PCT Int. Appl. WO2000018808, 2000. (k) Trifonov,
A. A.; Spaniol, T. P.; Okuda, J. Dalton Trans. 2004, 2245. (l) Arndt, S.;
Spaniol, T. P.; Okuda, J. Organometallics 2003, 22, 775.
* Corresponding author. E-mail: dmcui@ciac.jl.cn. Fax: (+86) 431
85262773. Tel: +86 431 85262773.
† Changchun Institute of Applied Chemistry.
‡ Graduate School of the Chinese Academy of Sciences.
§ Hubei University.
(1) (a) Hou, Z.; Wakatsuki, Y. Coord. Chem. ReV. 2002, 231, 1. (b)
Gromada, J.; Carpentier, J. F.; Mortreux, A. Coord. Chem. ReV. 2004, 248,
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Chem. Soc. 2005, 127, 14562. (c) Li, S.; Miao, W.; Tang, T.; Dong, W.;
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Organometallics 2007, 26, 5654.
10.1021/om801004r CCC: $40.75
2009 American Chemical Society
Publication on Web 01/21/2009

1454 Organometallics, Vol. 28, No. 5, 2009
Liu et al.
Scheme 1. Preparation of Complex 2
Table 1. Selected Bond Lengths and Bond Angles of Complex 2
clopentadienyl,8 and few bulky non-cyclopentadienyl ligands
such as ꢀ-diketimine,9 amidinate,6a,b,10 anilido-imine,11 aza
crown ethers,12 and tri(pyrazoly).13 Herein, we report the
synthesis of rare-earth metal hydrido and cationic intermediates
stabilized by anilido-phosphinimine auxiliary ligands and their
derivatives. Moreover, the reactions of the lutetium complex
with trimethylaluminum and phenylacetylene are also presented.
Bond Lengths (Å)
2.2276(16)
Y-O
Y-O(0A)
2.2622(16)
2.3311(19)
1.425(3)
Y-N(1)
Y-C(12)
P-C(7)
2.3042(18)
2.435(2)
1.811(2)
Y-N(2)
O-C(40)
C(7)-C(12)
1.404(3)
Bond Angles (deg)
O-Y-O(0A)
72.24(6)
136.92(15)
87.97(7)
122.29(6)
156.70(6)
77.73(7)
Y-O-Y(0A)
C(40)-O-Y(0A)
O-Y-C(12)
107.76(6)
115.27(14)
132.48(7)
92.00(6)
80.96(6)
107.23(16)
C(40)-O-Y
N(1)-Y-C(12)
O(0A)-Y-N(1)
O(0A)-Y-N(2)
N(2)-Y-C(12)
Results and Discussion
O-Y-N(2)
N(1)-Y-N(2)
C(7)-C(12)-Y
Synthesis of a Yttrium Hydride Intermediate and Its
Reactivity. Addition of phenylsilane to the hexane suspension
of yttrium mono(alkyl) complex 1a, LY(CH2Si(CH3)3)(THF)
(L ) o-(2,6-C6H3iPr2)NC6H4P(C6H4)(C6H5)N(2,4,6-C6H2Me3)),5a
at room temperature formed a clear solution within 1 h, which
was concentrated to 1 mL under reduced pressure and then kept
at -30 °C for several days. However, the hydrido complex could
not be obtained due to its good solubility. Using DME solvent
instead of hexane, anticipated to stabilize the metal-hydride
species, afforded a methoxy group bridged complex, 2, [LY(µ-
OCH3)]2 (δ 2.66 ppm for OCH3) (Scheme 1). This suggested
that the hydride complex was indeed formed, albeit as an
intermediate. Activated by the Lewis-acidic yttrium center, the
hydrido ligand nucleophilically attacked the methylene carbon
of DME with cleavage of the C-O bond. Meanwhile the
Y-CPhenyl bond remained untouched, which gave a doublet at
197.06 ppm, typical for the metal phenyl carbon Y-CPhenyl. This
result is different from the reaction between the linked amido-
cyclopentadienyl-ligated yttrium hydrido complex and DME,
in which the hydrido ligand neclueophilically attacks the methyl
carbon of DME to give a 2-methoxyethoxy-bridging complex,
[Y(L)(µ-OCH2CH2OMe-κO)]2.7k X-ray diffraction analysis shows
that each yttrium atom is coordinated by a CNN tridentate ligand
to form the dimeric complex 2 of Ci symmetry with two bridging
methoxy groups. The molecule adopts a pseudopyramidal
geometry with the N(2) atom apical and atoms N(1), C(12), O,
and O(0A) equatorial (Figure 1, Table 1, and STable 1). The
bridging Y-O bond distances are nearly equivalent (Y-O )
2.2276(16) Å, Y-O(0A) ) 2.2622(16) Å), close to those in
the dimeric enolate complex [Y(η5-MeC5H4)2(µ-OCHdCH2)]2.14
(8) Nishiura, M.; Mashiko, T.; Hou, Z. Chem. Commun. 2008, 2019.
(9) (a) Lee, L. W. M.; Piers, W. E.; Elsegood, M. R. J.; Clegg, W.;
Parvez, M. Organometallics 1999, 18, 2947. (b) Scollard, J. D.; McConville,
D. H. J. Am. Chem. Soc. 1996, 118, 10008. (c) Hayes, P. G.; Piers, W. E.;
Parvez, M. J. Am. Chem. Soc. 2003, 125, 5622. (d) Hayes, P. G.; Piers,
W. E.; Parvez, M. Organometallics 2005, 24, 1173. (e) Hayes, P. G.; Piers,
W. E.; McDonald, R. J. Am. Chem. Soc. 2002, 124, 2132. (f) Lauterwasser,
F.; Hayes, P. G.; Bra¨ se, S.; Piers, W. E.; Schafer, L. L. Organometallics
2004, 23, 2234.
(10) (a) Bambirra, S.; Van Leusen, D.; Meetsma, A.; Hessen, B.; Teuben,
J. H. Chem. Commun. 2003, 522. (b) Bambirra, S.; Bouwkamp, M. W.;
Meetsma, A.; Hessen, B. J. Am. Chem. Soc. 2004, 126, 9182. (c) Hessen,
B.; Bambirra, S. D. A. (Exxonmobil Chemical Patents Inc., USA). PCT
Int. Appl. WO2004000894, 2003.
(11) (a) Hayes, P. G.; Welch, G. C.; Emslie, D. J. H.; Noack, C. L.;
Piers, W. E.; Parvez, M. Organometallics 2003, 22, 1577. (b) Cameron,
T. M.; Gordon, J. C.; Michalczyk, R.; Scott, B. L. Chem. Commun. 2003,
2282.
(12) Lee, L.; Berg, D. J.; Einstein, F. W.; Batchelor, R. J. Organome-
tallics 1997, 16, 1819.
Due to the difficulty in the isolation of the yttrium hydrido
complex, we investigated its properties in situ. Excess isoprene
(13) (a) Cheng, J.; Saliu, K.; Kiel, G. Y.; Ferguson, M. J.; McDonald,
R.; Takats, J. Angew. Chem., Int. Ed. 2008, 47, 4910. (b) Lawrence, S. C.;
Ward, B. D.; Dubberley, S. R.; Kozak, C. M.; Mountford, P. Chem.
Commun. 2003, 2880.
(14) Evans, W. J.; Dominguez, R.; Hanusa, T. P. Organometallics 1986,
5, 1291.

ReactiVity of Rare-Earth Metal Complexes
Organometallics, Vol. 28, No. 5, 2009 1455
Figure 1. Molecular structure of 2 (hydrogen atoms omitted for
clarity; thermal ellipsoids with 50% probability).
Figure 3. Molecular structure of 4 (hydrogen atoms omitted for
clarity; thermal ellipsoids with 50% probability).
Scheme 2. Preparation of Complex 3
Figure 2. Molecular structure of 3 (hydrogen atoms omitted for
clarity; thermal ellipsoids with 50% probability).
was added to the mixture of 1a and phenylsilane to explore the
coordination behavior of an isoprene molecule. Concentration
of the reaction solution under reduced pressure followed by
cooling to -30 °C gave white solids of complex 3. The solid-
state structure of 3 determined by X-ray analysis (Stable 1) has
proved that one isoprene molecule inserts into a Y-H bond.
The resultant pentenyl unit adopts a syn-form coordinating to
the Lu ion in a η3-mode via atoms C(1) and C(3) (Figure 2).
The bond angle of C(1)-Y-C(3) (55.53(13)°) is in agreement
with a η3-coordination mode. The C(2)-C(3) bond length of
1.362(5) Å, which is close to that of a CdC double bond (1.34
Å), indicates that the Y-H species reacts via 1,4-addition with
the isoprene molecule. According to Evans’ group’s result that
anti- and syn-π-allylic isomers of Cp*Sm(η3-CH2CHCHCH3).15
The CNN tridentate ligand, the syn-pentenyl moiety, and a THF
molecule form a twisted trigonal-bipyramidal geometry around
the central metal with atoms C(21), N(1), and O in equatorial
and the pentenyl moiety and N(2) in axial positions. The bond
length of Y-C(1) (2.496(4) Å) is slightly shorter than those of
Y-C(2) (2.715(3) Å) and Y-C(3) (2.702(4) Å), which are close
tothevaluesintheliterature.16 ThebondangleofC(1)-C(2)-C(3)
(121.1(4)°) is smaller than that in [Y(η3-C3H5)3(µ-C4H8O2)]∞
(126.4(7)°).16a The pentenyl group is nearly coplanar with C(4)
and C(5), lying 0.05 and 0.17 Å above the C(1)C(2)C(3) plane,
respectively (Table 2).
1
in the H NMR spectrum of Cp*Sm(η3-CH2CHCHCH3) the
separate signals of the allyl moiety are assigned to the syn and
anti protons,7i the newly formed pentenyl moiety of complex 3
gave two sets of signals that could also be attributed to the syn-
π-allylic and anti-π-allylic isomers (Scheme 2). The methylene
protons of syn- and anti-CH2C(CH3)CHCH3 showed two dif-
ferent doublets at 0.75 and 0.62 ppm (2J(Y,H) ) 6.4 Hz),
respectively, with an intensity ratio of 3:1. This indicates that
the anti-isomer is less stable than the syn-isomer due to steric
repulsion, which is consistent with the DFT calculation on the
Synthesis and Reactivity of the Lutetium Cationic
Complex. Addition of equimolar [Ph3C][B(C6F5)4] · LiCl17 to
a toluene solution of 1b gradually afforded a white precipitate.
(15) Kaita, S.; Koga, N.; Hou, Z.; Doi, Y.; Wakatsuki, Y. Organome-
tallics 2003, 22, 3077.
(16) (a) Sanchez-Barba, L. F.; Hughes, D. L.; Humphrey, S. M.;
Bochmann, M. Organometallics 2005, 24, 3792. (b) Rodrigues, A.-S.;
Kirillov, E.; Lehmann, C. W.; Roisnel, T.; Vuillemin, B.; Razavi, A.;
Carpentier, J.-F. Chem.-Eur. J. 2007, 13, 5548.

1456 Organometallics, Vol. 28, No. 5, 2009
Liu et al.
Table 2. Selected Bond Lengths and Bond Angles of Complex 3
methylene protons of LuCH2Si(CH3)3 in B give one signal at
-0.35 ppm, which is different from the AB spin system with
signals at -0.78 and -0.87 ppm found in the precursor 1b.13
The formation of B from 1b is reversible. Complex B is cleaved
by the electron donor THF to give complex 5 as the major
product. This behavior was similar to that of [Me2Si(2-Me-
C9H5)2]Y[(µ-Me)(µ-iBu)AliBu2] decomposing to [Me2Si(2-Me-
C9H5)2]YMe(THF) and [Me2Si(2-Me-C9H5)2]YiBu(THF) in THF
(ca. 6:1 molar ratio).22 LuCH3 shows a singlet at a relatively
upfield position (-0.65 ppm) in contrast to that of the bridging
methyl in (NCNdipp)Y[(µ-Me)2AlMe2]2 (0.02 ppm)6e and {[κ3-
1-(NDipp)-2-(PPh(C6H4)dNDipp)C6H4]ScMe}2 (0.50 ppm).23
This result is consistent with the X-ray diffraction analysis,
where the methyl group of complex 5 coordinates to the metal
center in a terminal mode (STable 1 and Table 4). The auxiliary
ligand adopts a distorted octahedral geometry around the metal
center. Atoms C(1), O(1), C(35), and N(1) are equatorial, while
atoms O(2) and N(2) are located at the axial positions. The bond
length of Lu-C(1) (2.444(6) Å) is longer than that in the
analogous scandium dimethyl complex (av 2.343 Å), owing to
the large radius of the Lu ion.24
Reaction of Lutetium Monoalkyl Complex with Phenyl-
acetylene. Rare-earth metal aryl complexes have been covered
in the recent literature;25 however, their reactivities have been
less explored. According to the structures of 2, 3, and 5, we
concluded that the weak Lewis acid, such as PhSiH3 and AlMe3,
did not react with the metal phenyl group in complexes 1. Thus,
complex 1b was treated with a relatively strong Lewis acid,
phenylacetylene, to give complex 6. Obviously, the Lu-Cphenyl
bond was cleaved by phenylacetylene due to the absence of
the resonance for a metal phenyl carbon at ca. 200 ppm. X-ray
analysis confirmed that complex 6 is a monomeric lutetium
bis(alkynyl) complex, which, to the best of our knowledge,
represents the first non-Cp-ligated monomeric bis(alkynyl)
lanthanide. Complex 6 crystallizes in a triclinic unit cell (STable
1) with the ligands adopting a distorted octahedral geometry
around the Lu atom (Figures 4 and 5). The acetylide groups
are located at apexes forming a larger C-Lu-C angle (155.1(2)°)
in contrast to that (106.8(2)°) in the Cp-ligated monomeric
lutetium bis(acetylide), where the acetylide groups construct the
equator of a square-bipyramid. The acetylide bond lengths
Lu(1)-C(1) and Lu(1)-C(9) (2.395(6) and 2.424(6) Å) are
close to those (av 2.39 Å) in [Cp*Lu(CCPh)2(bipy)(py)].26 The
triple-bond distances C(1)-C(2) of 1.199(9) and C(9)-C(10)
of 1.204(9) Å are comparable to the literature values (av 1.209
Å) (Table 5).26,27
Bond Lengths (Å)
Y-N(1)
Y-O
2.322(3)
2.364(2)
2.496(4)
2.702(4)
1.362(5)
1.409(5)
Y-N(2)
Y-C(21)
Y-C(2)
C(1)-C(2)
C(3)-C(4)
2.361(3)
2.443(3)
2.715(3)
1.426(5)
1.519(5)
Y-C(1)
Y-C(3)
C(2)-C(3)
C(21)-C(26)
Bond Angles (deg)
N(1)-Y-C(21)
N(1)-Y-O
C(3)-C(2)-C(1)
N(1)-Y-N(2)
N(2)-Y-C(21)
N(2)-Y-C(2)
76.60(10)
174.01(8)
121.1(4)
82.71(9)
89.87(10)
159.09(10)
O-Y-C(21)
97.42(10)
55.53(13)
108.1(2)
97.68(8)
125.9(4)
C(1)-Y-C(3)
C(26)-C(21)-Y
N(2)-Y-O
C(2)-C(3)-C(4)
Filtration and removal of the volatiles left a yellow oil, which
was dissolved in DME/hexane to afford colorless crystals of 4,
which were characterized by X-ray analysis as the lutetium
chloride LLuCl(DME). The proposed reaction pathway was that,
first, complex 1b reacted with [Ph3C][B(C6F5)4] to afford the
cationic intermediate A, [LLu(DME)]+[B(C6F5)4]-, which trans-
formed into 4 via metathesis reaction with LiCl (Scheme 3).
This was proved further by the fact that the white precipitates
were [Li(DME)3]+[B(C6F5)4]-, confirmed by X-ray analysis
(SFigure 1). To the best of our knowledge, this represents the
first reaction between rare-earth metal cationic species and
inorganic salts, although Evans’ group had reported the reaction
of [Sm(η5-C5Me5)2(µ-Ph)2BPh2] with alkyl lithium or potassium
to afford bis(pentamethylcyclopentadienyl) rare-earth metal alkyl
complexes.18 The 13C NMR spectrum analysis indicated that
the Ln-Cphenyl bond remained untouched by giving a typical
downfield shift at 202.56 ppm. The auxiliary ligands adopt
bipyramidal geometry around the metal center (Figure 3 and
STable 1). Atoms N(2), C(15), O(1), and O(2) are equatorial,
with Lu lying 0.2491 Å below the plane, while atoms Cl(1)
and N(1) are located at the axial positions. The bond length
Lu-Cl(1) (2.5339(10) Å) (Table 3) is slightly shorter than 2.619
Å (av) for Ln-Clterminal given in the literature due to the lesser
steric environment around the Cl(1) atom.19
Reaction of Lutetium Monoalkyl Complex with Trimeth-
yl Aluminum. Our group has found that in some cases rare-
earth metal alkyl complexes activated by a perfluorinated
tetraphenylborate counterion, such as [Ph3C][B(C6F5)4], were
inert to the polymerization of dienes. Upon addition of AlR3,
the ternary system showed versatile activities depending on the
molar ratio of [Al]/[Ln].20 Moreover, the sterics of the R group
influenced the regioselectivity.4c,6d,g These results prompted us
to probe the reaction between rare-earth metal alkyl complexes
and aluminum trialkyls. Treatment of a THF solution of 1b by
excess AlMe3 (ca. 10 equiv) gave a methyl-terminated coun-
terpart, 5. The procedure might be depicted as shown in Schemes
4 and 5. Trimethyl aluminum coordinates to the metal center
by extruding a THF molecule to afford complex B.21 The
Conclusion
A yttrium mono(alkyl) complex stabilized by an anilido-
phosphinimine ligand reacted with PhSiH3 to afford the hydrido
intermediate. The hydrido group shows strong nucleophilicity
and attacks the methylene carbon of DME accompanied by the
(17) The synthesis procedure of [Ph3C][B(C6F5)4] · LiCl was included
in the Supporting Information.
(18) Evans, W. J.; Davis, B. L.; Ziller, J. W. Inorg. Chem. 2001, 40,
6341.
(19) (a) Kuo, P.; Chang, J.; Lee, W.; Lee, H. M.; Huang, J. J. Organomet.
Chem. 2005, 690, 4168. (b) Xue, M.; Yao, Y.; Shen, Q.; Zhang, Y. J.
Organomet. Chem. 2005, 690, 4685. (c) Glazier, M. J.; Levason, W.;
Matthews, M. L.; Thornton, P. L.; Webster, M. Inorg. Chim. Acta 2004,
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ReactiVity of Rare-Earth Metal Complexes
Organometallics, Vol. 28, No. 5, 2009 1457
Scheme 3. Preparation of Complex 4
1H and 13C NMR spectra were recorded on a Bruker AV400 (FT,
400 MHz for 1H; 100 MHz for 13C) spectrometer. NMR assignments
were confirmed by 1H-1H (COSY) and 1H-13C (HMQC) experi-
ments when necessary. Crystals for X-ray analysis were obtained
as described in the Experimental Section. The crystals were
manipulated in a glovebox. Data collections were performed at
-86.5 °C on a Bruker SMART APEX diffractometer with a CCD
area detector, using graphite-monochromated Mo KR radiation (λ
) 0.71073 Å). The determination of crystal class and unit cell
parameters was carried out by the SMART program package. The
raw frame data were processed using SAINT and SADABS to yield
the reflection data file. The structures were solved by the SHELXTL
program. CCDC-678678 (2), 6678679 (3), 678677 (4), 678676 (5),
and 678675 (6) contain the supplementary 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. Elemental analyses were performed at National
Analytical Research Centre of Changchun Institute of Applied
Chemistry.
Table 3. Selected Bond Lengths and Bond Angles of Complex 4.
Bond Lengths (Å)
Lu-N(1)
2.276(3)
2.417(3)
2.5339(10)
1.417(5)
Lu-N(2)
Lu-O(2)
Lu-C(15)
P-C(10)
2.285(3)
2.378(3)
2.359(4)
1.807(3)
Lu-O(1)
Lu-Cl(1)
C(10)-C(15)
Bond Angles (deg)
O(2)-Lu-O(1)
N(2)-Lu-C(15)
N(2)-Lu-Cl(1)
C(15)-Lu-Cl(1)
C(10)-C(15)-Lu
O(2)-Lu-Cl(1)
O(2)-Lu-N(1)
O(1)-Lu-N(2)
67.73(10)
90.54(11)
98.62(7)
99.80(9)
112.6(2)
91.26(8)
88.61(10)
173.70(10)
C(15)-Lu-O(1)
N(2)-Lu-O(2)
N(1)-Lu-N(2)
N(1)-Lu-C(15)
O(1)-Lu-Cl(1)
O(1)-Lu-N(1)
N(1)-Lu-Cl(1)
C(15)-Lu-O(2)
85.29(11)
115.16(10)
84.85(10)
78.57(11)
86.76(7)
89.68(10)
176.21(7)
150.25(11)
cleavage of a C-O bond, leading to the formation of a methoxy-
bridged complex, while isoprene insertion into the metal hydride
group gives a η3-pentenyl complex via 1,4-addition. The
lutetium mono(alkyl) analogue reacted with [Ph3C][B(C6F5)4] ·
LiCl and AlMe3 to afford the corresponding rare-earth metal
chloride and methyl complexes, respectively. In these processes
the metal-Cphenyl bonds have survived. However, treatment of
lutetium mono(alkyl) complex with PhCt CH generated a
relatively strong Lewis acid, the first non-Cp-ligated monomeric
lanthanide bis(alkynyl), via metathesis reaction between phe-
nylacetylene and metal-alkyl and the cleavage of the
metal-Cphenyl bond.
Yttrium Methoxy Complex 2. To a DME solution of complex
1a (0.15 g, 0.18 mmol), LY(CH2Si(CH3)3)(THF), was added phenyl-
silane (0.04 g, 0.37 mmol) in DME (1 mL). After 1 h, the reaction
mixture was concentrated to 0.5 mL under reduced pressure, then
diluted with hexane (1 mL). The solution was cooled to -30 °C for
several days to give white solids of complex 2, [LY(µ-OCH3)]2 (0.09
g, 73%). Crystals for X-ray analysis were obtained through recrystal-
lization from benzene/hexane at room temperature. 1H NMR(400 MHz,
2
[D6]benzene, 25 °C): δ 0.62(d, J(H, H) ) 6.8 Hz, 3H, NC6H3-
(CH(CH3)2)2), 0.73(d, 2J(H, H) ) 6.8 Hz, 3H, NC6H3(CH-
(CH3)2)2), 1.45(d, 2J(H, H) ) 6.8 Hz, 3H, NC6H3(CH(CH3)2)2), 1.92(d,
2J(H, H) ) 6.4 Hz, 3H, NC6H3(CH(CH3)2)2), 1.95(m, 1H,
NC6H3(CH(CH3)2)2), 2.03(s, 3H, NC6H2(CH3)3), 2.14(s, 3H,
NC6H2(CH3)3), 2.57(s, 3H, NC6H2(CH3)3), 2.66(s, 3H, YOCH3),
3.70(m, 1H, NC6H3(CH(CH3)2)2), 6.33(dd, 3J(H,H) ) 8.0 Hz, 4J(H,P)
) 6.0 Hz, 1H, o-YC6H4P), 6.55(td, 3J(H,H) ) 7.2 Hz, 4J(H,H) ) 2.8
Hz, 1H, m-PC6H4Y), 6.60(s, 1H, m-NC6H2Me3), 6.87(s, 1H,
m-NC6H2Me3), 6.95(td, J(H,H) ) 8.0 Hz, J(H,H) ) 2.8 Hz, 2H,
m-PC6H5), 7.00(dd, 3J(H,H) ) 7.2 Hz, 4J(H,H) ) 1.6 Hz, 1H,
m-NC6H3iPr2),7.06(m, 1H, p-PC6H5, 1H, p-PC6H4Y), 7.20(m, 1H,
p-NC6H3iPr2, 1H, m-PC6H4N), 7.34(t, 3J(H,H) ) 7.2 Hz, 1H,
Experimental Section
General Methods. All reactions were carried out under a dry
and oxygen-free argon atmosphere using Schlenk techniques or in
a glovebox. Solvents were purified by a MBraun SPS system. All
starting materials were purchased from Aldrich or Fluka and
distilled before use. Syntheses of rare earth metal alkyl complexes,
LLn(CH2Si(CH3)3)(THF) (L ) o-(2,6-C6H3iPr2)NC6H4P(C6H5)(C6H4)-
N(2,4,6-C6H2Me3), 1a, Ln ) Y; 1b, Ln ) Lu),5a were carried out
according to the literature.
3
4
Instruments and Measurements. Organometallic samples for
NMR spectroscopic measurements were prepared in a glovebox.

1458 Organometallics, Vol. 28, No. 5, 2009
Scheme 4. Metathetic Reaction between Complex 1b and AlMe3
Liu et al.
Scheme 5. Preparation of Complex 6
NC6H3(CH(CH3)2)2), 25.54(s, 1C, NC6H3(CH(CH3)2)2), 25.76(s, 1C,
NC6H3(CH(CH3)2)2), 27.25(s, 1C, NC6H3(CH(CH3)2)2), 27.83(s, 1C,
NC6H3(CH(CH3)2)2), 30.86(s, 1C, NC6H3(CH(CH3)2)2), 50.46(s, 1C,
YOCH3), 113.48(d, 3J(C,P) ) 12 Hz, 1C, m-PC6H4Y), 114.07(s, 1C,
o-NC6H3iPr2), 115.02(s, 1C, o-NC6H3iPr2), 117.32 (d, 3J(C,P) ) 8 Hz,
1C, o-YC6H2P), 124.28(s, 1C, p-NC6H3iPr2), 125.08, 125.26(s, 1C,
o-PC6H4Y, 1C, p-PC6H4N), 126.65, 126.93(s, 2C, m-NC6H3iPr2),
128.00(overlap, 1C, m-PC6H4N), 129.00, 129.26, 129.57(s, 1C,
m-NC6H2Me3, 1C, p-PC6H5, 1C, p-PC6H4Y), 131.65, 132.04, 132.15,
132.30(s, 2C, m-PC6H5, 1C, m-NC6H2Me3, 1C, o-PC6H4N), 132.87(s,
1C, p-NC6H2Me3), 134.74(s, 1C, o-PC6H5), 134.81(s, 1C, o-PC6H5),
135.41(d, J(C,P) ) 5 Hz, 1C, o-NC6H2Me3), 136.46(d, J(C,P))6
Hz, 1C, o-NC6H2Me3), 137.25(s, 1C, o-NC6H4P), 137.48(s, 1C, ipso-
PC6H4N), 141.46(s, 1C, ipso-NC6H4P), 144.69(d, 1J(C,P) ) 9 Hz, 1C,
ipso-PC6H4Y), 145.41(s, 1C, ipso-NC6H3iPr2), 150.25(s, 1C, ipso-
NC6H2Me3), 159.88(d, 1J(C,P) ) 5 Hz, 1C, ipso-PC6H5), 197.06 ppm
3
3
Table 4. Selected Bond Lengths and Bond Angles of Complex 5
Bond Lengths (Å)
Lu-N(1)
2.325(5)
2.432(5)
2.444(6)
1.396(9)
Lu-N(2)
Lu-O(2)
C(35)-Lu
C(40)-P
2.270(5)
2.350(4)
2.477(7)
1.812(6)
Lu-O(1)
C(1)-Lu
C(35)-C(40)
Bond Angles (deg)
N(2)-Lu-C(35)
N(1)-Lu-C(35)
O(2)-Lu-O(1)
N(2)-Lu-C(1)
C(40)-C(35)-Lu
O(2)-Lu-C(35)
N(1)-Lu-C(1)
N(2)-Lu-O(2)
77.04(19)
88.1(2)
81.09(19)
93.5(2)
108.1(4)
96.95(19)
107.09(19)
173.89(16)
N(2)-Lu-N(1)
O(1)-Lu-C(1)
O(2)-Lu-C(1)
N(1)-Lu-O(2)
O(1)-Lu-C(35)
N(2)-Lu-O(1)
N(1)-Lu-O(1)
C(35)-Lu-C(1)
84.27(17)
83.2(2)
92.0(2)
96.79(17)
82.1(2)
96.8(2)
169.59(18)
161.4(2)
3
4
p-PC6H4N), 7.41(dd, J(H,H) ) 7.2 Hz, J(H,H) ) 1.6 Hz, 1H,
3
4
m-NC6H3iPr2), 7.53(dd, J(H,H) ) 8.0 Hz, J(H,H) ) 1.6 Hz, 1H,
3
3
o-PC6H4Y), 7.63(d, J(H,H) ) 7.2, 1H, o-PC6H4N), 7.73(d, J(H,H)
3
) 7.2 Hz, 1H, o-PC6H5), 7.76(d, J(H,H) ) 7.2 Hz, 1H, o-PC6H5),
8.05 ppm (d, 3J(H,H) ) 7.1 Hz, 1H, o-NC6H4P). 13C NMR (400 MHz,
[D6]benzene, 25 °C): δ 20.19(s, 1C, p-NC6H2(CH3)3), 21.24(s, 1C,
o-NC6H2(CH3)3),22.14(s, 1C, o-NC6H2(CH3)3), 24.70(s, 1C,
Figure 5. Molecular structure of 6 (hydrogen atoms omitted for
clarity; thermal ellipsoids with 50% probability).
Table 5. Selected Bond Lengths and Bond Angles of Complex 6
Bond Lengths (Å)
Lu-N(1)
Lu-C(1)
Lu-O(1)
C(1)-C(2)
C(9)-C(10)
2.253(4)
2.395(6)
2.469(4)
1.199(9)
1.204(9)
Lu-N(2)
2.259(5)
2.424(6)
2.421(4)
1.442(9)
1.443(9)
Lu-C(9)
Lu-O(2)
C(2)-C(3)
C(10)-C(11)
Bond Angles (deg)
N(1)-Lu-O(1)
N(2)-Lu-O(2)
C(1)-Lu-C(9)
C(10)-C(9)-Lu
C(9)-C(10)-C(11)
C(9)-Lu-O(2)
C(9)-Lu-N(2)
C(1)-Lu-O(2)
C(1)-Lu-N(2)
N(1)-Lu-O(2)
109.31(15)
95.17(15)
155.1(2)
175.9(5)
179.0(7)
79.87(17)
99.42(18)
80.71(18)
97.71(19)
175.01(15)
O(2)-Lu-O(1)
N(1)-Lu-N(2)
C(2)-C(1)-Lu
C(1)-C(2)-C(3)
C(9)-Lu-O(1)
C(9)-Lu-N(1)
C(1)-Lu-O(1)
C(1)-Lu-N(1)
N(2)-Lu-O(1)
69.92(14)
85.97(16)
166.9(5)
176.4(7)
83.13(17)
95.15(17)
75.63(18)
103.98(18)
164.32(15)
Figure 4. Molecular structure of 5 (hydrogen atoms omitted for
clarity; thermal ellipsoids with 50% probability).

ReactiVity of Rare-Earth Metal Complexes
Organometallics, Vol. 28, No. 5, 2009 1459
(d, 1J(C,Y) ) 36 Hz, 1C, ipso-YC6H4P). Anal. Calcd for
C80H98N4O2P2Y2: C, 69.26; H, 7.12; N, 4.04. Found: C, 69.25; H, 7.10;
N, 4.03.
NC6H3(CH(CH3)2)2), 59.23(s, 1C, (CH3OCH2)2), 62.53(s, 1C,
(CH3OCH2)2), 71.38(s, 1C, (CH3OCH2)2), 72.40(s, 1C, (CH3OCH2)2),
113.48(d, 3J(C,P) ) 12 Hz, 1C, m-PC6H4Y), 115.40(s, 1C,
o-NC6H3iPr2), 115.62(s, 1C, o-NC6H3iPr2), 119.41 (d, 3J(C,P) ) 9 Hz,
1C, o-YC6H2P), 122.44(s, 1C, p-NC6H3iPr2), 124.68, 125.84(s, 1C,
o-PC6H4Y, 1C, p-PC6H4N), 126.34, 126.43(s, 2C, m-NC6H3iPr2),
126.82(s, 1C, m-PC6H4N), 129.94, 130.25, 130.47(s, 1C, m-NC6H2Me3,
1C, p-PC6H5, 1C, p-PC6H4Y), 131.20, 131.31, 132.22, 132.43(s, 2C,
m-PC6H5, 1C, m-NC6H2Me3, 1C, o-PC6H4N), 133.07(s, 1C,
p-NC6H2Me3), 133.17(s, 1C, o-PC6H5), 133.83(s, 1C, o-PC6H5),
134.83(d, 3J(C,P) ) 8 Hz, 1C, o-NC6H2Me3), 136.84(d, 3J(C,P) ) 6
Hz, 1C, o-NC6H2Me3), 137.76(s, 1C, o-NC6H4P), 139.63(s, 1C, ipso-
PC6H4N), 139.86(s, 1C, ipso-NC6H4P), 145.33(s, 1C, ipso-PC6H4Y),
147.67(s, 1C, ipso-NC6H3iPr2), 149.07(s, 1C, ipso-NC6H2Me3), 161.24(d,
1J(C,P) ) 5 Hz, 1C, ipso-PC6H5), 202.56 ppm (d, 1J(C,P) ) 35 Hz,
1C, ipso-YC6H4P). Anal. Calcd for C43H51N2O2PclLu: C, 59.41; H,
5.91; N, 3.22. Found: C, 59.41; H, 5.92; N, 3.21.
Yttrium Pentenyl Complex 3. Phenylsilane (0.03 g, 0.27 mmol)
in toluene (1 mL) was dropwise added into a toluene solution of 1a
(0.12 g, 0.15 mmol), LY(CH2Si(CH3)3)2(THF). After 1 h, isoprene
(0.68 g, 10 mmol) was added to the above solution. AFter stirring for
6 h at room temperature, the reaction mixture was concentrated to 0.5
mL under reduced pressure, then diluted with hexane (1 mL). The
solution was cooled at -30 °C for several days to give white solids
of complex 3 (0.08 g, 71%), LLn(CH2C(CH3)dCHCH3)(THF).
Recrystallization from benzene/hexane at room temperature afforded
crystals that were good enough for X-ray analysis. 1H NMR (400 MHz,
[D6]benzene, 25 °C): δ 0.62(d, 2J(Y,H) ) 6.4 Hz, 2H, anti-
CH2C(CH3)dCHCH3), 0.75(d, 2J(Y,H)
) 6.4 Hz, 2H, syn-
CH2C(CH3)dCHCH3), 1.34(br, 4H, THF), 1.44(d, 3J(H,H) ) 6.8 Hz,
3
3H, NC6H3(CH(CH3)2)2), 1.46(d, J(H,H) ) 7.2 Hz, 3H, NC6H3-
(CH(CH3)2)2), 1.54(d, 3J(H,H)
)
7.2 Hz, 3H, NC6H3-
Lutetium Methyl Complex 5. To a THF solution of complex 1b
(0.15 g, 0.17 mmol), LLu(CH2Si(CH3)3)(THF), was added AlMe3 (0.12
g, 1.70 mmol) in THF (1 mL). After 2 h, the reaction mixture was
concentrated to 0.5 mL under reduced pressure, then diluted with
hexane (1 mL) followed by cooling to -30 °C, and kept for several
days, giving white solids of complex 5, LLu(CH3)(THF)2 (0.09 g,
3
(CH(CH3)2)2), 1.62(d, J(H,H) ) 7.2 Hz, 3H, NC6H3(CH(CH3)2)2),
1.95(s, 3H, syn-CH2C(CH3)dCHCH3), 2.05(s, 3H, anti-
CH2C(CH3)dCHCH3) 2.11(d, 3J(H,H)
CH2C(CH3)dCHCH3), 2.14(d, 3J(H,H)
)
)
2.4 Hz, 3H, anti-
2.0 Hz, 3H, syn-
CH2C(CH3)dCHCH3), 2.23(multi, 1H, syn-CH2C(CH3)dCHCH3),
2.33(multi, 1H, anti-CH2C(CH3)dCHCH3), 2.66(s, 3H, p-C6H2(CH3)3),
2.79(s, 6H, o-C6H2(CH3)3), 3.44(br, 4H, THF), 3.78(multi, 1H,
NC6H3(CH(CH3)2)2), 4.42(multi, 1H, NC6H3(CH(CH3)2)2), 6.26(dd,
1
60%). H NMR (400 MHz, [D6]benzene, 25 °C): δ -0.65(s, 3H,
LuCH3), 0.80(d, 3J(H,H) ) 7.2 Hz, 6H, NC6H3(CH(CH3)2)2), 1.49(br,
8H, THF), 1.34(d, 3J(H,H) ) 7.2 Hz, 6H, NC6H3(CH(CH3)2)2), 2.32(s,
3H, NC6H2(CH3)3), 2.49(s, 3H, NC6H2(CH3)3), 2.58(s, 3H,
3
3J(H,H) ) 8.0 Hz, J(H,Y) ) 6.0 Hz, 1H, syn-o-YC6H4P), 6.33(dd,
3
3J(H,H) ) 8.0 Hz, J(H,Y) ) 6.0 Hz, 1H, anti-o-YC6H4P), 6.48(td,
NC6H2(CH3)3),
3.67(br,
8H,
THF),
3.81(multi,
2H,
4
3
3J(H,H) ) 7.2 Hz, J(H,H) ) 2.8 Hz, 1H, m-PC6H4Y), 6.57(s, 1H,
NC6H3(CH(CH3)2)2), 6.31(d, J(H,H) ) 8.0 Hz, 1H, o-LuC6H4P),
6.49(t, 3J(H,H) ) 7.2 Hz, 1H, m-PC6H4Lu), 6.72(s, 1H, m-NC6H2Me3),
6.78(s, 1H, m-NC6H2Me3), 6.93-6.99(multi, 2H, m-NC6H3iPr2),
7.09(m, 1H, p-PC6H5, 1H, p-PC6H4Y), 7.20(m, 1H, p-NC6H3iPr2, 1H,
m-PC6H4N), 7.37(t, 3J(H,H) ) 7.2 Hz, 1H, p-PC6H4N), 7.43-7.53(multi,
1H, o-PC6H4Y, 2H, m-PC6H5), 7.56(d, 3J(H,H) ) 7.2, 1H, o-PC6H4N),
7.79(multi, 2H, o-PC6H5), 8.07 ppm (d, 3J(H,H) ) 7.1 Hz, 1H,
o-NC6H4P). 13C NMR (400 MHz, [D6]benzene, 25 °C): δ 20.13(s,
1C, NC6H2(CH3)3), 21.33(s, 1C, NC6H2(CH3)3), 21.92(s, 1C,
NC6H2(CH3)3), 23.49(s, 2C, NC6H3(CH(CH3)2)2), 24.63(s, 2C,
NC6H3(CH(CH3)2)2), 26.19(s, 4C, THF), 27.39(s, 1C,
NC6H3(CH(CH3)2)2), 29.78(s, 1C, NC6H3(CH(CH3)2)2), 68.54(s, 4C,
THF), 113.41(s, 1C, m-PC6H4Lu), 113.53(s, 1C, o-NC6H3iPr2), 114.13(s,
1C, o-NC6H3iPr2), 117.86(s, 1C, o-LuC6H2P), 123.71(s, 1C,
p-NC6H3iPr2), 124.90(s, 1C, o-PC6H4Lu), 125.40(, 1C, p-PC6H4N),
126.23(s, 2C, m-NC6H3iPr2), 126.91(s, 1C, m-PC6H4N), 131.10, 131.67,
132.07(s, 1C, m-NC6H2Me3, 1C, p-PC6H5, 1C, p-PC6H4Y), 132.39,
132.65, 132.80(s, 2C, m-PC6H5, 1C, m-NC6H2Me3, 1C, o-PC6H4N),
134.10(s, 1C, p-NC6H2Me3), 134.58(s, 2C, o-PC6H5), 134.86(s, 1C,
o-NC6H2Me3), 135.97(s, 1C, o-NC6H2Me3), 137.83(s, 1C, o-NC6H4P),
139.74(s, 1C, ipso-PC6H4N), 139.92(s, 1C, ipso-NC6H4P), 143.43(s,
1C, ipso-PC6H4Lu), 147.50(s, 1C, ipso-NC6H3iPr2), 148.34(s, 1C, ipso-
NC6H2Me3), 150.08(d, 1J(C,P) ) 5 Hz, 1C, ipso-PC6H5), 201.56 ppm
(s, 1C, ipso-LuC6H4P). Anal. Calcd for C48H60N2O2Plu: C, 63.85; H,
6.70; N, 3.10. Found: C, 63.84; H, 6.68; N, 3.09.
m-NC6H2Me3), 6.87(s, 1H, m-NC6H2Me3), 6.93(td, 3J(H,H) ) 8.0 Hz,
4J(H,H) ) 2.8 Hz, 2H, m-PC6H5), 7.01(dd, 3J(H,H) ) 7.2 Hz, 4J(H,H)
) 1.6 Hz, 1H, m-NC6H3iPr2), 7.05(m, 1H, p-PC6H5, 1H, p-PC6H4Y),
7.22(m, 1H, p-NC6H3iPr2, 1H, m-PC6H4N), 7.31(t, 3J(H,H) ) 7.2 Hz,
1H, p-PC6H4N), 7.42(dd, 3J(H,H) ) 7.2 Hz, 4J(H,H) ) 1.6 Hz, 1H,
m-NC6H3iPr2), 7.54-7.73(m, 1H, o-PC6H4Y, 1H, o-PC6H4N, 1H,
o-PC6H5), 7.80(d, 3J(H,H) ) 7.2 Hz, 1H, o-PC6H5), 8.27(d, 3J(H,H)
) 7.2 Hz, 1H, syn-o-NC6H4P), 8.43 ppm (d, 3J(H,H) ) 6.8 Hz, 1H,
anti-o-NC6H4P). Anal. Calcd for C48H58N2OPLu C, 65.15; H, 6.61;
N, 3.17. Found: C, 65.13; H, 6.60; N, 3.16.
Lutetium Chloro Complex 4. [Ph3C][B(C6F5)4] · LiCl (0.13 g,
0.13 mmol) in 2 mL of DME was added to a toluene solution of
complex 1b (0.12 g, 0.13 mmol). After 30 min, filtration afforded a
white solid, which was [Li(DME)3]+[B(C6F5)4]-, confirmed by X-ray
analysis. Removal of the volatiles of the filtrate left a yellow oil, which
was diluted by hexane/DME. The mixture was kept at -30 °C for
several days to afford complex 4, LLuCl(DME) (0.10 g, 90%), as
colorless crystals. 1H NMR(400 MHz, [D6]benzene, 25 °C): δ 0.74(d,
2J(H, H) ) 6.8 Hz, 3H, NC6H3(CH(CH3)2)2), 1.49(d, 2J(H, H) ) 6.8
Hz, 3H, NC6H3(CH(CH3)2)2), 1.50(d, 2J(H, H) ) 6.8 Hz, 3H,
NC6H3(CH(CH3)2)2), 1.67(d, 2J(H, H)
)
6.8 Hz, 3H,
NC6H3(CH(CH3)2)2), 1.90(s, 3H, NC6H2(CH3)3), 2.16(s, 3H,
NC6H2(CH3)3), 2.61(multi, 1H, NC6H3(CH(CH3)2)2), 2.71(s, 3H,
NC6H2(CH3)3), 3.06(br, 4H, (CH3OCH2)2), 3.19(s, 6H, (CH3OCH2)2),
3
4.01(multi, 1H, NC6H3(CH(CH3)2)2), 6.35(dd, J(H,H) ) 8.4 Hz,
Lutetium Bis(alkynyl) Complex 6. Phenylacetylene (0.03 g, 0.29
mmol) in DME (1 mL) was dropwise added into a DME solution of
1a (0.13 g, 0.14 mmol), LLu(CH2Si(CH3)3)(THF). After stirring for
2 h at room temperature, the reaction mixture was concentrated to 0.5
mL under reduced pressure, then diluted with hexane (1 mL) followed
by cooling at -30 °C for several days, to give red crystals of complex
6 (0.10 g, 66%), LLu(Ct CPh)2(DME). 1H NMR (400 MHz,
[D6]benzene, 25 °C): δ 1.48(d, 2J(H, H) ) 6.8 Hz, 6H,
3J(H,Lu) ) 6.4 Hz, 1H, o-YC6H4P), 6.44(td, 3J(H,H) ) 7.2 Hz, 4J(H,H)
) 2.8 Hz, 1H, m-PC6H4Y), 6.52(s, 1H, m-NC6H2Me3), 6.86(s, 1H,
m-NC6H2Me3), 6.95-7.05(mutil, 1H, m-NC6H3iPr, 2H, m-PC6H5, 1H,
p-PC6H5,), 7.24(t, 3J(H,H) ) 7.6 Hz, 1H, p-PC6H4Y), 7.36-7.54(m,
1H, p-NC6H3iPr2, 1H, m-PC6H4N, 1H, p-PC6H4N, 1H, m-NC6H3iPr2,
3
3
1H, o-PC6H4Y), 7.68(dd, J(H,H) ) 8.4 Hz, J(H,P) ) 8.4 Hz,1H,
o-PC6H4N), 7.88(d, 3J(H,H) ) 7.2 Hz, 1H, o-PC6H5), 7.90(d, 3J(H,H)
) 7.2 Hz, 1H, o-PC6H5), 8.51 ppm (d, 3J(H,H) ) 6.8 Hz, 1H,
o-NC6H4P). 13C NMR (400 MHz, [D6]benzene, 25 °C): δ 20.46(s,
1C, NC6H2(CH3)3), 21.14(s, 1C, NC6H2(CH3)3), 21.25(s, 1C,
NC6H2(CH3)3), 24.93(s, 1C, NC6H3(CH(CH3)2)2), 25.12(s, 1C,
NC6H3(CH(CH3)2)2), 26.33(s, 1C, NC6H3(CH(CH3)2)2), 27.32(s, 1C,
NC6H3(CH(CH3)2)2), 28.69(s, 1C, NC6H3(CH(CH3)2)2), 29.40(s, 1C,
NC6H3(CH(CH3)2)2), 1.78(d, 2J(H, H)
)
6.8 Hz, 6H,
NC6H3(CH(CH3)2)2), 2.23(s, 3H, p-NC6H2(CH3)3), 2.35(s, 6H,
o-NC6H2(CH3)3), 2.98(s, 6H, (CH3OCH2)2), 3.42(br, 4H, (CH3OCH2)2),
4.49(br, 2H, NC6H3(CH(CH3)2)2), 6.25(dd, 3J(H,H) ) 8.0 Hz, 3J(H,P)
3
) 8.0 Hz, 1H, o-PC6H4N), 6.53(t, J(H,H) ) 6.8 Hz, m-NC6H4P),
3
6.87(s, 2H, m-NC6H2Me3), 6.92(d, J(H,H) ) 7.2 Hz, o-NC6H4P),

1460 Organometallics, Vol. 28, No. 5, 2009
Liu et al.
7.03-7.11(m, 2H, p-Ct CC6H5, 2H, p-P(C6H5)2, 4H, m-P(C6H5)2, 1H,
137.65(s, 2C, o-NC6H3iPr2), 139.19(s, 1C, ipso-PC6H4N), 139.68(s,
2C, ipso-P(C6H5)2), 143.29(s, 1C, o-NC6H4P), 149.64(s, 1C, ipso-
NC6H2Me3), 157.76(s, 1C, ipso-NC6H3iPr2), 162.63 ppm (s, 2C,
Ct CC6H5). Anal. Calcd for C59H62N2O2PLu: C, 68.33; H, 6.03; N,
2.70. Found: C, 68.31; H, 6.03; N, 2.69.
3
p-NC6H4P), 7.20(t, J(H,H) ) 7.6 Hz, 4H, m-Ct CC6H5), 7.43(t,
3J(H,H) ) 7.2 Hz, 1H, p-NC6H3iPr2), 7.52-7.58(m, 4H, o-Ct CC6H5,
2H, m-NC6H3iPr2), 8.03(d, 3J(H,H) ) 7.6 Hz, 2H, o-PC6H5), 8.06 ppm
(d, 3J(H,H) ) 7.6 Hz, 2H, o-PC6H5). 13C NMR (400 MHz, [D6]benzene,
25 °C): δ 21.33(s, 1C, p-NC6H2(CH3)3), 21.40(s, 2C, o-NC6H2(CH3)3),
25.22(s, 2C, NC6H3(CH(CH3)2)2), 27.08(s, 2C, NC6H3(CH(CH3)2)2),
29.21(s, 2C, NC6H3(CH(CH3)2)2), 60.47(s, 2C, (CH3OCH2)2), 72.29(s,
2C, (CH3OCH2)2), 106.83(s, 2C, Ct CC6H5), 112.83(d, 2J(P,C) ) 15
Acknowledgment. We are grateful for financial support
from the National Natural Science Foundation of China for
project nos. 20571072 and 20674081, the Ministry of Science
and Technology of China for project no. 2005CB623802,
and the “Hundred Talent Program” of CAS.
3
Hz, 1C, o-PC6H4N), 119.65(d, J(P,C) ) 9 Hz, 1C, m-NC6H4P),
124.74(s, 1C, p-NC6H2Me3), 125.72(s, 2C, o-Ct CC6H5), 125.90(s,
2C, o-Ct CC6H5), 126.61(s, 1C, p-NC6H3iPr2), 128.50(overlap, 4C,
m-Ct CC6H5), 129.25(s, 2C, p-P(C6H5)2), 130.42(s, 2C, m-NC6H2Me3),
131.38(s, 2C, o-NC6H2Me3), 132.04(s, 2C, m-NC6H3iPr2), 132.16(s,
4C, m-P(C6H5)2), 133.08(s, 1C, m-Ct CC6H5), 133.17(s, 1C,
m-Ct CC6H5), 133.75(s, 2C, p-Ct CC6H5), 134.03(s, 1C, p-NC6H4P),
135.69(d, 2J(P,C) ) 9 Hz, 4C, o-P(C6H5)2), 137.51(s, 1C, o-NC6H4P),
Supporting Information Available: This material is available
free of charge via the Internet at http://pubs.acs.org.
OM801004R