Versatile reactivity of scorpionate-anchored yttrium-dialkyl complexes towards unsaturated substrates

Article abstract of DOI:10.1002/chem.201300610

A series of unusual chemical-bond transformations were observed in the reactions of high active yttrium-dialkyl complexes with unsaturated small molecules. The reaction of scorpionate-anchored yttrium-dibenzyl complex [Tp^Me2Y(CH₂Ph)₂(thf)] (1, Tp ^Me2=tri(3,5-dimethylpyrazolyl)borate) with phenyl isothiocyanate led to C=S bond cleavage to give a cubane-type yttrium-sulfur cluster, {Tp ^Me2Y(μ₃-S)}₄ (2), accompanied by the elimination of PhN=C(CH₂Ph)₂. However, compound 1 reacted with phenyl isocyanate to afford a C(sp³)-H activation product, [Tp^Me2Y(thf){μ-η¹:η³-OC(CHPh)NPh} {μ-η³:η²-OC(CHPh)NPh}YTp^Me2] (3). Moreover, compound 1 reacted with phenylacetonitrile at room temperature to produce γ-deprotonation product [(Tp^Me2)₂Y] ⁺[Tp^Me2Y(N=C=CHPh)₃]^- (6), in which the newly formed N=C=CHPh ligands bound to the metal through the terminal nitrogen atoms. When this reaction was carried out in toluene at 120 °C, it gave a tandem γ-deprotonation/insertion/partial-Tp^Me2- degradation product, [(Tp^Me2Y)₂(μ-Pz) ₂{μ-η¹:η³-NC(CH₂Ph)CHPh}] (7, Pz=3,5-dimethylpyrazolyl).

Full text of DOI:10.1002/chem.201300610

FULL PAPER
DOI: 10.1002/chem.201300610
À
Versatile Reactivity of Scorpionate-Anchored Yttrium Dialkyl Complexes
towards Unsaturated Substrates
Weiyin Yi,[a] Jie Zhang,*[a] Fangjun Zhang,[a] Yin Zhang,[a] Zhenxia Chen,[a] and
Xigeng Zhou*[a, b]
Abstract: A series of unusual chemical-
bond transformations were observed in
PhN=C
G
to produce g-deprotonation product
[(TpMe2)2Y]+A[TpMe2 (N=C=CHPh)3]À
1 reacted with phenyl isocyanate to
G
YACHTUNGTRENNUNG
À
the reactions of high active yttrium di-
afford a C
[TpMe2
{m-h3:h2-OC
(6), in which the newly formed N=C=
CHPh ligands bound to the metal
through the terminal nitrogen atoms.
When this reaction was carried out in
toluene at 1208C, it gave a tandem g-
alkyl complexes with unsaturated small
molecules. The reaction of scorpionate-
Y
À
anchored yttrium dibenzyl complex
Moreover, compound 1 reacted with
phenylacetonitrile at room temperature
[TpMe2
Y
(CH2Ph)
T
=
tri(3,5-dimethylpyrazolyl)borate) with
phenyl isothiocyanate led to C=S bond
cleavage to give a cubane-type yttri-
deprotonation/insertion/partial-TpMe2
degradation product, [(TpMe2Y)
2A(m-
Pz)2{m-h1:h3-NC
(CH2Ph)CHPh}] (7,
Pz=3,5-dimethylpyrazolyl).
-
CHTUNGTRENNUNG
Keywords: C H activation · cleav-
age reactions · heterocycles · inser-
tion · yttrium
AHCTUNGTRENNUNG
um–sulfur cluster, {TpMe2
YAHCUTNGERN(NUG m3-S)}4 (2),
accompanied by the elimination of
À
Introduction
earth-metal dihydrides “LLnH2” exhibit remarkable reac-
tivity toward some unsaturated substrates, such as PhCN,
CO, and CO2, which is exquisitely different from those of
rare-earth-metal monohydrides,[7] we decided to investigate
what new unique properties might be derived from coopera-
tive interactions between two alkyl ligands.
À
Rare-earth-metal dialkyl complexes that contain monoa-
nionic ancillary ligands (LLnR2) have occupied a central
place in the organometallic chemistry of these elements
over the last decade, because the presence of two highly re-
active s-bonded hydrocarbon ligands may impart a marked
reactivity onto their rare-earth-metal complexes that is diffi-
cult or impossible to achieve from their corresponding mon-
oalkyl compounds.[1] These complexes not only react facilely
with the appropriate borate compounds, such as [Ph3C][B-
Herein, we report the synthesis of scorpionate-anchored
yttrium dibenzyl complex [TpMe2Y
C
G
À
reaction behavior towards a series of unsaturated substrates,
which show interesting reactivity and lead to new products.
The reaction products have been identified by X-ray diffrac-
tion analysis, thus demonstrating that the two benzyl ligands
can undergo various tandem reactions with one unsaturated
molecule in an unprecedented manner.
ACHTUNGTRENNUNG(C6F5)4] or [PhNMe2H][BAHCTUNGTRNE(NUGN C6F5)4], to generate cationic mon-
oalkyl species that serve as excellent catalysts for the poly-
merization and copolymerization of a variety of olefins,[2]
but they are also useful precursors for the synthesis of a
wide range of rare-earth-metal derivatives, such as rare-
earth-metal polyhydrides,[3] rare-earth-metal terminal-imido
Results and Discussion
À
complexes,[4] and rare-earth-metal carbene complexes.[5]
À
Tris(pyrazolyl)borates (TpR,R’) are among the most-versatile
and most widely used supporting ligands in inorganic and or-
ganometallic chemistry,[8] owing to the facile manipulation
of their steric profile by variation of the substituents at the
À
However, the reactivity of rare-earth-metal dialkyl com-
plexes towards unsaturated substrates has remained almost
unexplored so far.[6] Encouraged by the results that rare-
3-positions of the pyrazolyl rings. Mono-TpR,R’ yttrium dia-
À
[a] Dr. W. Yi, J. Zhang, Prof. Dr. F. Zhang, Y. Zhang, Dr. Z. Chen,
Prof. Dr. X. Zhou
lkyl complexes [(TpMe,R)Y
(CH2SiMe3)
2A
R=tBu, x=0) have been synthesized by salt metathesis and
Department of Chemistry
Shanghai Key Laboratory of Molecular Catalysis and
Innovative Materials
Fudan University, Shanghai 200433 (P. R. China)
E-mail: zhangjie@fudan.edu.cn
alkane elimination, respectively.[3e,9] Recently, we tried to
prepare
mono-TpMe2
yttrium di-silylamide
complex
À
[TpMe2Y(N
(SiMe3)2)2] by using salt metathesis between
[TpMe2YCl
2ACHTUNRGTENNUG(thf)2] and KNCAHUTNTGREN(NGUN SiMe3)2; however, we only isolat-
[b] Prof. Dr. X. Zhou
À
ed the g-methyl-deprotonation or Si Me bond-cleavage
State Key Laboratory of Organometallic Chemistry
Shanghai 200032 (P. R. China)
E-mail: xgzhou@fudan.edu.cn
products.[10] However, the mono-TpMe2 yttrium dibenzyl
À
complex [TpMe2
Y
G
(thf)] (1) was facilely prepared by
Chem. Eur. J. 2013, 19, 11975 – 11983
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11975

the reaction of [TpMe2YCl
KCH2Ph in THF at room temperature and was isolated in
91% yield as colorless air- and moisture-sensitive crystals
(Scheme 1). The constitution of compound 1 was unequivo-
(thf)2] with two equivalents of
This equivalence of the two benzyl groups was also con-
1
firmed by the H and 13C NMR spectra of compound 1 in
1
solution. In the H NMR (C6D6, RT) spectrum of compound
1, the three single peaks at d=5.55, 2.38, and 2.10 ppm are
attributed to the 4-H-TpMe2 and Me-TpMe2 groups, respec-
tively, and the three multiple peaks at d=7.21–6.80 ppm are
attributed to the phenyl-ring protons of the two benzyl
groups. However, the CH2 peak of the benzyl group is
buried in the peak of 5-Me-TpMe2 at d=2.10 ppm. Thus, we
1
studied the variable-temperature H NMR spectra of com-
pound 1 (À40 to 608C, [D8]THF) and found that the original
signal at d=2.10 ppm (C6D6, RT) split into two signals at
d=2.26 and 2.20 ppm ([D8]THF, À408C) in a 4:6 ratio,
which were assignable to the resonances of the CH2Ph and
Me-TpMe2 groups, respectively. Moreover, the resonances at
d=2.38 and 2.20 ppm are assignable to the Me-TpMe2 groups
in a 12:6 ratio. Notably, the integral ratio for the peaks of
Me-TpMe2 at d=2.38 and 1.0 ppm in C6D6 at room tempera-
ture is 6:12, but it changes into 12:6 in [D8]THF at À408C
(d=2.37 and 2.23 ppm). This result might be attributable to
the solution effects of C6D6 and [D8]THF.
Scheme 1. Synthesis of compounds 2 and 3 from compound 1.
The reaction of compound 1 with one equivalent of
phenyl isothiocyanate smoothly took place at room temper-
ature in THF. After workup, the structurally characterized
cally established by single-crystal X-ray diffraction analysis
(Figure 1), which indicated that compound 1 was a solvate
monomer, in which the yttrium atom was bonded to a k3-
TpMe2 ligand, two h1-benzyl groups, and one coordinated thf
molecule to form a distorted octahedral geometry. No multi-
hapto interactions were observed between the yttrium atom
and the two benzyl groups in the solid state.[11] The two
metal complex {TpMe2
YACHTUNGRTENNUGN
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
1
GCMS and H NMR spectroscopy. X-ray analysis revealed
that compound 2 adopted a tetranuclear cubane-like Y4S4
core structure that was formed from four “TpMe2
YACHTUNGTRENNUNG(m3-S)”
units (Figure 2).[13] Each yttrium atom was ligated by a k3-
almost-equivalent Y C bond lengths (Y1 C1 2.457(8) ꢁ,
scorpionate-TpMe2 ligand (Y1 N1 2.519(3) ꢁ, Y1 N1A
À
À
À
À
À
À
À
Y1 C8 2.418(8) ꢁ) indicate that they are standard yttrium
2.519(3) ꢁ, Y1 N1B 2.519(3) ꢁ) and three m3-bridging
À
À
À
carbon s bonds and these values are comparable to the cor-
S atoms (Y1 S2 2.6704(9) ꢁ, Y1 S2A 2.6704(9) ꢁ, Y1 S2C
À
responding values in other lanthanide benzyl complexes,
[12]
À
such as [Y
N
G
Figure 2. Molecular structure of compound 2; thermal ellipsoids are set
at 30% probability. Carbon atoms on the TpMe2 moiety and all hydrogen
atoms are omitted for clarity. Selected bond lengths [ꢁ] and angles [8]:
Figure 1. Molecular structure of compound 1; thermal ellipsoids are set at
À
À
À
À
30% probability. Hydrogen atoms are omitted for clarity. Selected bond
Y1 S2 2.6704(9), Y1 S2A 2.6704(9), Y1 S2C 2.6704(9), Y1 N1 2.519(3),
À
À
À
À
À
lengths [ꢁ] and angles [8]: Y1 C1 2.457(8), Y1 C8 2.418(8), Y1 O1
Y1 N1A 2.519(3), Y1 N1B 2.519(3); S2-Y1-S2A 85.59(4), S2-Y1-S2C
85.59(4), S2A-Y1-S2C 85.59(4), Y1-S2-Y1A 94.25(3), Y1-S2-Y1C
94.25(3), Y1A-S2-Y1C 94.25(3).
À
À
À
2.335(5), Y1 N2 2.502(6), Y1 N4 2.378(6), Y1 N6 2.485(6); Y1-C1-C2
116.4(6), Y1-C8-C9 130.1(6).
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À
Reactivity of Scorpionate-Anchored Yttrium Dialkyl Complexes
FULL PAPER
2.6704(9) ꢁ). Cubane cluster 2 is similar to the known tet-
raoxo complex Cp’4Y4O4 (Cp’=C5Me4SiMe3).[7e]
The formation of compound 2 indicated that a new C=S
double-bond cleavage occurred during the isothiocyanate-in-
sertion process. It is known that the insertion of isothiocya-
À
nate into metal ligand bonds usually leads to the formation
of insertion products,[14] whilst the C=S double-bond cleav-
age of the isothiocyanate unit has only rarely been ob-
served.[15] The behavior of phenyl isothiocyanate in the reac-
tion between compound 1 and PhNCS is similar to that of
phenyl isocyanate in the reaction of yttrium polyhydride
with PhNCO, which results in the cleavage of the C=O
double bond.[7g] Thus, we speculate that the formation of
À
compound 2 might undergo a continuous Y C s-bond-inser-
tion process, as shown in Scheme 2.
Figure 3. Molecular structure of compound 3; thermal ellipsoids are set
at 30% probability. Hydrogen atoms are omitted for clarity. Selected
À
À
À
bond lengths [ꢁ] and angles [8]: Y1 N1 2.296(6), Y1 O1 2.353(5), Y1
À
À
À
O2 2.276(5), Y2 N2 2.312(7), Y2 O1 2.209(5), Y2 O2 2.383(5),
À
À
À
Y1···H16 2.478(5), C1 N1 1.393(9), C1 O1 1.388(8), C1 C2 1.374(10),
À
À
À
C15 N2 1.333(9), C15 O2 1.365(8), C15 C16 1.398(10); N1-C1-O1
105.2(8), N1-C1-C2 136.5(8), O1-C1-C2 118.1(9), N2-C15-O2 112.6(9),
N2-C15-C16 133.4(9), O2-C15-C16 115.2(7).
TpMe2 group. The CHPh fragment that is bound to the
PhNCO unit is observed as a singlet at d=4.73 ppm and the
13C NMR spectrum of compound 3 shows one resonance at
d=68.07 ppm, which is assignable to the CHPh proton. In
an attempt to obtain more details about the agostic Y···H in-
teraction in solution, we also studied the variable-tempera-
ture 1H NMR spectra of compound 3·THF (from À40 to
608C in [D8]THF). The single peak at d=4.83 ppm, which is
assignable to the two CHPh groups, does not split into two
single peaks in [D8]THF at À408C. However, the two over-
lapping peaks that are assignable to 3-Me-TpMe2 and 5-Me-
TpMe2 at d=2.16–2.02 ppm split into four single peaks at d=
2.42, 2.38, 2.24, and 1.94 ppm in a 6:12:6:12 ratios and the
single peak at d=5.57 ppm (C6D6, RT), which is assignable
to the 4H-TpMe2 group, also splits into two single peaks at
d=5.85 and 5.65 ppm in a 2:4 ratio in [D8]THF at À408C.
Thus, we speculate that compound 3·THF adopts a C2v-sym-
metric structure in solution, owing to the fast dissociation/
re-addition of THF (the THF molecule in the crystal lattice
in C6D6 or the [D8]THF molecule in [D8]THF). Indeed, we
also cannot exclude the possibility that the agostic Y···H
solid-state structure is maintained in solution, but undergoes
rapid fluxional behavior, thus giving a time-averaged solu-
tion structure that has higher symmetry than the C1-symmet-
ric solid-state structure.
Scheme 2. Plausible reaction process for the formation of compound 2.
The significant difference between the reactivities of yttri-
[14a]
À
À
um monobenzyl and yttrium dibenzyl complexes
to-
wards phenyl isothiocyanate led us to explore other hetero-
allenes, such as phenyl isocyanate. An equimolar reaction of
compound 1 with phenyl isocyanate in THF at room temper-
ature afforded an insertion and benzyl-deprotonation prod-
uct, 3·THF, in 72% yield (Scheme 1). The solid-state struc-
ture of compound 3·THF was also determined by single-
crystal X-ray diffraction. Figure 3 shows that the two newly
formed OCACHTUNGTRENNUNG
(CHPh)NPh ligands are bonded to two Y3+ ions
in a bridged and side-on bonding mode and that there is an
agostic Y···H interaction between the Y1 ion and the CHPh
À
À
moiety (Y1···H 2.478(5) ꢁ). The C1 C2 and C15 C16
(1.374(10) and 1.398(10) ꢁ) bond lengths are significant
À
shorter than that of a C C single bond (1.50 ꢁ), thus indi-
cating partially delocalized double-bond character. Consis-
À
À
tent with this observation, the C1 N1 (1.393(9) ꢁ) and C1
O1 bonds (1.388(8) ꢁ) are slightly shorter than those of C-
2
2
À
À
À
À
G
U
The C=C double-bond character of the C1 C2 and C15
C16 bonds in compound 3 were also confirmed by the fol-
lowing reaction: Complex 3 can further react with Me3SiCl
under mild conditions to give a nucleophilic-addition prod-
uct (4) in 87% yield, as shown in Scheme 3. Its solid-state
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
dicate charge delocalization. In the 1H NMR spectrum of
compound 3·THF at room temperature in C6D6, the single
peak at d=5.57 ppm is assigned to the resonance of the 4H-
TpMe2 group and the two overlapping single peaks at d=
2.02–2.16 ppm are assigned to the resonances of the Me-
À
structure (Figure 4) reveals that the Si Cl bond of the
À
Me3SiCl group added across the Y N bond and that the
Me3Si group is bonded with the CHPh moiety through a
1,3-migration process. Compound 4 contains a monoanionic
Chem. Eur. J. 2013, 19, 11975 – 11983
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11977

J. Zhang, X. Zhou et al.
À
dergoes an insertion of phenyl isocyanate into one Y
CH2Ph bond, followed by g-deprotonation and PhCH3-elei-
À
mation processes. Considering the fact that no ytterbium al-
kylidene intermediate was determined in the H NMR spec-
1
trum of compound 1, we suggest that path b is more likely.
Moreover, the result of the reaction of compound 1 with
carbodiimide can also be used to exclude path a (see
below).
Scheme 3. Synthesis of compound 4 from compound 3.
The treatment of compound 1 with one equivalent of
ArN=C=NAr in THF at room temperature produced a mon-
oinsertion product, [TpMe2
YAHCTUNRGEN(NUG CH2Ph){(RN)2CACHTUNGTRENN(UNG CH2Ph)}] (5,
Ar=C6H3-iPr-2,6), in almost-quantitative yield (Scheme 5).
Scheme 5. Synthesis of compound 5 from compound 1.
Complex 5 does not undergo further transformations, such
as proton abstraction from the CH2Ph group of the amidi-
nate ligand or the elimination of PhCH3, similar to com-
pound 3, even at elevated temperatures (808C) for 24 h.
Figure 4. Molecular structure of compound 4; thermal ellipsoids are set
at 30% probability. Hydrogen atoms are omitted for clarity. Selected
À
À
À
bond lengths [ꢁ] and angles [8]: Y1 O1 2.305(2), Y1 N1 2.420(3), Y1
À
These results might suggest that the ytterbium alkylidene
À
À
À
Cl1 2.568(1), C1 O1 1.283(4), C1 N1 1.326(5), C1 C2 1.511(5); O1-C1-
N1 115.7(3), O1-C1-C2 118.0(3), N1-C1-C2 126.3(4).
intermediate is not formed during the process for the forma-
tion of compound 3 (Scheme 4, path a).
Single-crystal analysis (Figure 5) and 1H and 13C NMR
spectroscopy confirmed that compound 5 was a mixed
amido ligand, OC(CH
ACHTUNGRTEN(NUNG SiMe3)Ph)NPh, and has incorporated
a chloride ligand into the coordination sphere of the metal.
TpMe2/amidinate yttrium monobenzyl complex. In the
1H NMR spectrum of compound 5, the two single peaks at
d=5.63 and 5.30 ppm were assigned to the resonances of
the 4H-TpMe2 group in a 1:2 ratio, whilst the four single
peaks at d=2.50, 2.07, 1.94, and 1.87 ppm were assigned to
the resonances of the Me-TpMe2 protons in a 3:6:3:6 ratio.
À
À
À
The C1 C2 bond length (1.511(5) ꢁ) corresponds to a
standard single bond. A singlet peak at d=3.16 ppm is as-
3
À
signed to the C
G
N
1
group in the H NMR spectrum of compound 4. These re-
sults also indicate that a new C
the CH2Ph ligand has been realized by the reactions from
compound 1 to compound 4.
We speculate that the formation of compound 3 might
proceed through two different pathways, as outlined in
Scheme 4. In path a, compound 1 undergoes a PhCH3-elimi-
[5]
À
nation step to yield a metal carbene intermediate; then,
À
the cycloaddition of isocyanate to the ytterbium alkylidene
intermediate forms compound 3. In path b, compound 1 un-
Figure 5. Molecular structure of compound 5; thermal ellipsoids are set
at 30% probability. Hydrogen atoms are omitted for clarity. Selected
À
À
À
bond lengths [ꢁ] and angles [8]: Y1 N1 2.390(2), Y1 N2 2.379(2), Y1
À
À
À
C33 2.451(3), C1 N1 1.331(3), C1 N2 1.336(3), C1 C2 1.520(4); N1-C1-
N2 115.5(2), N1-C1-C2 122.7(3), N2-C1-C2 121.8(3).
Scheme 4. Plausible reaction processes for the formation of compound 3.
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À
Reactivity of Scorpionate-Anchored Yttrium Dialkyl Complexes
FULL PAPER
Two multiple peaks at d=3.95 and 3.45 ppm are assigned to
the resonances of the HC
peaks (J=6.4) at d=1.62, 1.50, 0.93, and 0.84 ppm are as-
signed to the resonances of the HC(CH3)2 groups in a
ACHTUGNTERN(NUNG CH3)2 groups and the four double
AHCTUNGTRENNUNG
6:6:6:6 ratio. These results indicate that compound 5 is a Cs-
symmetrical solution. Two characteristic single peaks at d=
3.84 and 2.11 ppm are assigned to the resonances of the NC-
À
ACHTUNGTRENNUNG(CH2Ph)N and Y CH2Ph groups, respectively. Consistent
with this observation, two resonances at d=56.42 and
À
35.24 ppm, which were assignable to the Y CH2Ph and NC-
A
(CH2Ph)N groups, were observed in the 13C NMR spectrum
of compound 5. The molecular structure and important
bond lengths and angles are listed in Figure 5. The central
metal ion, Y3+, is bonded to one k3-TpMe2 group, one h1-
benzyl group, and one chelating amidinate ligand to form a
Scheme 6. Two routes for the synthesis of compound 7 from compound 1.
À
distorted octahedral geometry. The two C N bond lengths
À
À
of the amidinate group (C1 N1 and C1 N2, 1.331(3) and
1.336(3) ꢁ, respectively) are approximately equivalent and
that the PhCHCN ligand contained a ketenimine skeleton
(Figure 6). Moreover, the newly formed N=C=CHPh anion-
ic ligands bound to the central metal through a terminal ni-
2
3
À
significantly shorter than the lengths of the CACTHNUTRGENUG(N sp ) N (sp )
single bonds (1.47–1.50 ꢁ), thus indicating that the p elec-
À
trons of the C=N double bond in these structures are delo-
trogen atom (Y1 N1 2.252(5) ꢁ). To the best of our knowl-
edge, this bond mode of the ketenimino ligand to lanthanide
À
À
calized over the NCN unit. The Y N1 and Y N2 distances
(2.390(2) and 2.379(2) ꢁ) are intermediate between the
ions has not previously been reported.[17]
À
À
values for a Y N single bond and a Y N coordinate bond
and are longer than the corresponding values in [Cp2Y-
À
À
ACHTUNGTRENNUNG{(tBuN)2CnBu}] (Y N1 and Y N2, 2.301(3) and 2.302(3),
respectively).[16] This result may be attributed to the larger
steric hindrance of the TpMe2 group compared with the Cp
group, which decreases the interaction between the Y and
À
À
N atoms. The Y1 C33 (2.451 ꢁ) bond is a normal Y C
À
s bond. The C1 C2 bond (1.520(4) ꢁ) is consistent with a
À
carbon carbon single bond.
Investigations of the reactivity of rare-earth-metal alkyl
complexes toward organic nitriles provide many important
organometallic reactions and interesting structures and they
À
have found that they usually react with nitriles to give the
[17]
À
insertion or C H activation products. However, no exam-
À
ples of reaction of rare-earth-metal dialkyl complexes with
nitriles have been reported so far. To further explore the re-
À
activity of the yttrium dialkyl complex, we also investigated
Figure 6. Anionic structure of compound 6; thermal ellipsoids are set at
30% probability. Hydrogen atoms are omitted for clarity. Selected bond
the reaction of compound 1 with phenylacetonitrile and
found that compound 1 could react with one equivalent of
phenylacetonitrile in THF at room temperature to afford a
À
À
À
lengths (ꢁ) and bond angles (8): Y1 N1 2.252(5), Y1 N2 2.313(6), Y1
À
À
À
À
N3 2.290(5), N1 C1 1.177(9), C1 C2 1.382(10), N2 C9 1.127(8), C9 C10
structurally characterized complex, [(TpMe2)2Y]
+A
Y
A
À
À
1.357(10), N3 C17 1.133(8), C17 C18 1.381(10); N1-C1-C2 178.5(8), N2-
C9-C10 176.6(10), N3-C17-C18 178.0(8).
C=CHPh)3]À(6), in 70% yield (based on the reaction stoichi-
ometry), thus indicating that PhCH2CN underwent a g-de-
protonation step to form an anionic ketenimino ligand that
adopted an unusual bonding mode. When the reaction was
carried out in toluene at 1208C, a tandem g-deprotonation/
The crystal structure of compound 7 is shown in Figure 7
and shows that the dianionic 1-azaallyl ligand [PhCH=C-
insertion/partial-TpMe2-degradation product, [(TpMe2Y)
Pz)2{m-h1:h3-NC
(CH2Ph)CHPh}] (7, Pz=3,5-dimethylpyra-
zolyl), was isolated in 34% yield (based on the Y metal), as
shown in Scheme 6. The H NMR spectrum of compound 6
2A
(CH2Ph)N]2À has been formed through the insertion of the
ACHTUNGTRENNUNG
anionic PhCH=C=NÀ group into the Y C
ACTHUNGTERNNU(G benzyl) s bond.
À
G
À
À
The C1 C2 and C2 N1 bond lengths, 1.373(12)
1
and1.335(12) ꢁ, adopt intermediate values between the cor-
À
À
showed a single resonance at d=5.94 ppm, which was as-
signable to the N=C=CHPh unit. Consistent with this obser-
vation, the bond parameters, such as N1-C1-C2 178.5(8)8,
responding C C and C N single- and double-bond lengths,
thus indicating that the p electrons of the C=C double bond
in this structure are partially delocalized over the C-C-N
unit.[18] The Y1 N1 distance (2.147(7) ꢁ) is significantly
À
À
À
N1 C1 1.177(9) ꢁ, and C1 C2 1.382(10) ꢁ, also suggested
Chem. Eur. J. 2013, 19, 11975 – 11983
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
11979

J. Zhang, X. Zhou et al.
tained on a Bruker DMX-400 NMR spectrometer (1H: 400 MHz, 13C:
100 MHz).
Synthesis of [TpMe2
(KCH2Ph, 0.260 g, 2.00 mmol) was added to a solution of [TpMe2YCl2-
(thf)] (0.529 g, 1.00 mmol) in THF (20 mL) at RT. After stirring over-
YACHTNGUTRENU(NG CH2Ph)2ACHTNUGTREN(NGNU thf)] (1): In a glove box, benzyl potassium
AHCTUNGTRENNUNG
night, the thick, pale-red solution was evaporated to dryness under
vacuum and toluene (30 mL) was added to the residue. After stirring for
30 min, the mixture was filtered through Celite and the filtrate was con-
centrated to about 10 mL and then layered with n-hexane to afford com-
pound 1 as colorless crystals. Yield: 0.583 g (91%); 1H NMR (100 MHz,
C6D6, RT): d=7.17–7.21 (m, 8H; C6H5), 6.80 (m, 2H; C6H5), 5.55 (s, 3H;
4H-TpMe2), 3.47 (m, 4H; O
(two overlapping peaks, 16H; CH3 of TpMe2 and CH2Ph), 1.11 ppm (m,
4H; O
(CH2CH2)2), 2.38 (s, 6H; CH3 of TpMe2), 2.10
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
to 608C): at À408C: d=6.80 (m, 4H; C6H5), 6.67 (m, 4H; C6H5), 6.36
(m, 2H; C6H5), 5.77 (s, 3H; 4H-TpMe2), 2.37 (s, 12H; CH3 of TpMe2), 2.28
(s, 4H; CH2Ph), 2.23 (s, 6H; CH3 of TpMe2); variable-temperature
1H NMR ([D8]THF, from À40 to 608C): at 608C: d=6.77 (m, 4H; C6H5),
6.66 (m, 4H; C6H5), 6.34 (m, 2H; C6H5), 5.77 (s, 3H; 4H-TpMe2), 2.35 (s,
12H; CH3 of TpMe2), 2.26 (s, 4H; CH2Ph), 2.20 ppm (s, 6H, CH3 of
TpMe2); 13C NMR (100 MHz, C6D6, RT): d=154.70 (s; 3-C-Pz), 145.66 (s;
5-C-Pz), 128.49 (s; CH2C6H5), 124.45 (s; CH2C6H5), 117.08 (s; CH2C6H5),
À
Figure 7. Molecular structure of compound 7; thermal ellipsoids are set at
30% probability. Hydrogen atoms are omitted for clarity. Selected bond
À
À
À
lengths [ꢁ] and angles [8]: Y1 N1 2.147(7), Y2 N1 2.315(8), Y2 C1
À
À
À
À
2.678(11), Y2 C2 2.675(11), N1 C2 1.335(12), C2 C1 1.373(12), C2 C3
1.563(13); N1-C2-C1 120.9(9), N1-C2-C3 119.1(9), C1-C2-C3 119.8(9).
106.30 (s; 4-C-Pz), 71.11 (s; thf), 56.26 (d, JACHTNUTRGEN(UGN Y,C)=34 Hz; Y CH2C6H5),
25.07 (s; thf), 14.30 (s; 3-Me-Pz), 13.07 ppm (s; 5-Me-Pz). elemental anal-
ysis calcd (%) for C33H44BN6OY: C 61.89, H 6.92, N 13.12; found:
C 62.12, H 7.01, N 12.89.
À
shorter than that of the Y2 N1 bond (2.315(8) ꢁ) and is
Synthesis of {TpMe2
YAHCUTNGERN(NUG m3-S)}4 (2): In a glove box, phenyl isothiocyanate
comparable to the values in rare-earth-metal-bridged imido
(0.068 g, 0.50 mmol) was slowly added to a solution of compound 1
(0.320 g, 0.50 mmol) in THF (15 mL). After stirring overnight at RT, the
solution was concentrated to dry under reduced pressure. To the residue
was added toluene (5 mL) and then n-hexane was diffused into the con-
centrated toluene solution to give colorless crystals of compound 2.
Yield: 0.569 g (68%);. 1H NMR (100 MHz, C6D6, RT): d=5.56 (s, 3H;
4H-TpMe2), 2.75 (s, 9H; CH3 of TpMe2), 2.06 ppm (s, 9H; CH3 of TpMe2);
13C NMR (100 MHz, C6D6, RT): d=150.91 (s; 3-C-Pz), 148.79 (s; 5-C-
Pz), 107.12 (s; 4-C-Pz), 14.36 (s; 3-Me-Pz), 12.94 ppm (s; 5-Me-Pz); ele-
mental analysis calcd (%) for C60H88B4N24S4Y4: C 43.08, H 5.30, N 20.10;
found: C 42.85, H 5.24, N 20.29.
complexes.[7 h] Moreover, the almost-equivalent lengths of
À
À
the Y2 C1 (2.678(11) ꢁ) and Y2 C2 bonds (2.675(11) ꢁ)
À
shows that the C1 C2 double bond is coordinated to the Y2
ion in a side-on bonding mode. The source of the 3,5-dime-
thylpyrazolyl group might be the degradation of the TpMe2
ligand at high temperatures.[19]
Conclusion
The mother solution was concentrated to dryness under reduced pressure
to give an oily mixture. Then, the oily mixture was abstracted twice with
n-hexane (10 mL). After removing the volatile compounds, the impure
In summary, we have investigated the equimolar reactions
À
of rare-earth-metal dialkyl complexes with some unsaturat-
organic byproduct PhN=CACHTUNRGTNEUNG(CH2Ph)2 was obtained and purified by fast
column chromatography on silica gel. Yield: 0.091 g (64%); 1H NMR
(100 MHz, CDCl3, RT): d = 3.94 (s, 4H; CH2Ph), 7.01–7.48 ppm (m,
15H; C6H5).[21]
ed substrates and revealed some unusual chemical-bond
3
À
transformations, such as C=S cleavage and C
G
tion or functionalization. These results indicate that the
Synthesis
of
[TpMe2 (thf){m-h1:h3-OC(CHPh)NPh}{m-h3:h2-OC-
YAHCTUNGTRENNUGN ACHTUNGTRENNNUG
À
presence of two highly active metal carbon s bonds in the
AHCTUNGTRENNUNG
dialkyl complexes offers a greater variety of reactivity
beyond insertion compared to its monoalkyl analogue.
was added to a solution of compound 1 (0.448 g, 0.70 mmol) in THF
(15 mL) at RT. After stirring overnight, the reaction mixture was worked
up by using the method described for the synthesis of compound 2. Col-
orless crystals of compound 3·THF were obtained in 72% yield (0.673 g).
1H NMR (400 MHz, C6D6, RT): d=6.24–8.04 (m, 20H; C6H5), 5.57 (s,
6H; 4H-TpMe2), 4.73 (s, 2H; CHPh), 3.52 (m, 8H; O
2.16 (two overlapping peaks, 36H; CH3-TpMe2), 1.44 ppm (m, 8H; O-
(CH2CH2)2); variable-temperature 1H NMR ([D8]THF, from À40 to
ACHTNUGTNER(NUGN CH2CH2)2), 2.02–
Experimental Section
AHCTUNGTRENNUNG
General methods: All of the reactions were carried out under a dry and
inert atmosphere by using either standard Schlenk techniques or under a
nitrogen atmosphere in an MBRAUN glove box. The nitrogen gas in the
glove box was constantly circulated through a copper/molecular sieves
catalyst unit. The oxygen and moisture concentrations in the glove box
were monitored by an O2/H2O Combi-Analyzer (MBRAUN) to ensure
that both concentrations stayed below 1 ppm. The THF, toluene, and n-
hexane solvents were heated at reflux and distilled over sodium benzo-
phenone ketyl under a nitrogen atmosphere immediately prior to use.
608C): at À408C: d=7.48 (m, 4H; C6H5), 6.78 (m, 4H; C6H5), 6.64 (m,
4H; C6H5), 6.53 (m, 4H; C6H5), 6.25 (m, 4H; C6H5), 5.85 (s, 2H; 4H-
TpMe2), 5.65 (s, 4H; 4H-TpMe2), 4.83 (s, 2H; CHPh), 2.42 (s, 6H; CH3 of
TpMe2), 2.38 (s, 12H; CH3 of TpMe2), 2.24 (s, 6H; CH3 of TpMe2), 1.94 ppm
(s, 12H; CH3 of TpMe2); variable-temperature 1H NMR ([D8]THF, from
À40 to 608C): at 608C: d=7.48 (m, 4H; C6H5), 6.79 (m, 4H; C6H5), 6.52
(m, 4H; C6H5), 6.22 (m, 8H; C6H5), 5.67 (s, 6H; 4H-TpMe2), 4.83 (s, 2H;
CHPh), 2.38 (s, 24H; CH3 of TpMe2), 2.05 ppm (s, 12H; CH3 of TpMe2);
13C NMR (100 MHz, C6D6, RT): d=167.81 (s; OCN), 154.68 (s; 3-C-Pz),
152.38 (s; 3-C-Pz), 150.41 (s; 3-C-Pz), 149.77 (s; 5-C-Pz), 146.50 (s; 5-C-
Pz), 145.23 (s; 5-C-Pz), 124.32 (s; CH2C6H5), 121.19 (s; CHC6H5), 116.53
(s; CHC6H5), 115.94 (s; CHC6H5), 105.82 (s; 4-C-Pz), 75.67 (s; thf), 68.07
(s; CHC6H5), 25.82 (s; thf), 14.23 (s; 3-Me-Pz), 13.00 (s; 5-Me-Pz),
[TpMe2YCl2ACHTUNGTRENNUNG
(thf)2][20a] and KCH2Ph[20b] were prepared according to litera-
ture methods. Phenyl isothiocyanate (PhNCS), phenyl isocyanate
(PhNCO), and phenyacetonitrile (PhCH2CN) were purchased from Al-
drich and used without further purification. Elemental analysis was car-
ried out on a Rapid CHN-O analyzer. 1H and 13C NMR data were ob-
11980
www.chemeurj.org
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2013, 19, 11975 – 11983

À
Reactivity of Scorpionate-Anchored Yttrium Dialkyl Complexes
FULL PAPER
12;73 ppm (s, 5-Me-Pz); IR (KBr): n˜ =2525 cmÀ1 (BÀH); elemental anal-
ysis calcd (%) for C66H82N14B2O4Y2: C 59.38, H 6.19, N 14.69; found:
C 59.67, H 6.22, N 14.45.
2ACTHUNGTRENUNG ACHTUNGTERN(NUNG CH2Ph)CHPh}] (7, Pz=3,5-
Synthesis of [(TpMe2Y) (m-Pz)2{m-h1:h3-NC
dimethylpyrazolyl): In a glove box, a mixture of compound 1 (0.320 g,
0.50 mmol) and PhCH2CN (0.059 g, 0.5 mmol) in toluene (15 mL) was
heated in 1208C for 24 h. The solution was concentrated to dryness
under vacuum, the residue was washed with n-hexane (2ꢂ10 mL), and
the solution in n-hexane was slowly vaporized in the glove box to afford
colorless crystals of compound 7. Yield: 0.100 g (34% based on the Y
metal); 1H NMR (400 MHz, C6D6, RT): d=6.79–7.13 (m, 10H, C6H5),
5.60 (two overlapping peaks, 8H; 4H-TpMe2 and 4H-pyrazolyl), 4.02 (s,
1H; CHPh), 3.59 (s, 2H; CH2Ph), 1.99–2.39 (m, 36H; CH3 of TpMe2),
1.64 (s, 3H; 3-CH3-pyrazolyl), 1.40 (s, 3H; 3-CH3-pyrazolyl), 1.24 ppm (s,
6H; 5-CH3-pyrazolyl); 13C NMR (100 MHz, C6D6, RT): d=208.64 (s;
NCC), 150.92 (s; 3-C-Pz), 150.15 (s; 3-C-Pz), 144.99 (s; 5-C-Pz), 142.97
(s; 5-C-Pz), 137.89 (s; 3-C-pyrazolyl), 131.46 (s; 5-C-pyrazolyl), 129.33 (s;
C6H5), 128.58 (s; C6H5), 128.19 (s; C6H5), 128.17 (s; C6H5), 127.62 (s;
C6H5), 125.71 (s; C6H5), 105.98 (s; 4-C-Pz), 105.25 (s; 4-C-pyrazolyl),
43.77 (s; NCCHC6H5), 31.99 (s; CH2C6H5), 14.38 (s; 3-Me-Pz), 13.13 (s;
3-Me-pyrazolyl), 13.05 (s; 5-Me-Pz), 12.63 ppm (s; 5-Me-pyrazolyl); ele-
mental analysis calcd (%) for C55H71B2N17Y2: C 56.48, H 6.12, N 20.36;
found: C 56.21, H 6.05, N 20.63.
Synthesis of [TpMe2YCl(h2-N(Ph)C
ACHTUNGTRENNUNG ACHUTGTNERN{UNG CHPhACHTUNGETRN(GNUN SiMe3)}O)ACHTUNGTREN(NNGU thf)] (4): In a glove
box, Me3SiCl (0.054 g, 0.50 mmol) was slowly added to a solution of com-
pound 3 (0.667 g, 0.50 mmol) in THF (10 mL) at RT. After stirring over-
night, the reaction mixture was concentrated to dryness under reduced
pressure. The residue was dissolved in toluene (6 mL). Colorless crystals
of compound 4 were achieved in 74% yield (0.574 g) by the diffusion of
n-hexane into a solution of compound 4 in toluene. 1H NMR (400 MHz,
C6D6, RT): d = 7.03–7.45 (m, 10H; C6H5), 5.64 (s, 1H; 4H-TpMe2), 5.51 (s,
2H; 4H-TpMe2), 3.59 (m, 4H; O
6H; CH3-TpMe2), 2.06 (s, 12H; CH3-TpMe2), 1.18 (m, 4H; O
0.35 (s, 3H; Si(CH3)3), 0.30 ppm (s, 6H; Si
(CH3)3); 13C NMR (100 MHz,
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
A
ACHTUNGTRENNUNG
C6D6, RT): d=183.35 (s; OCN), 150.79 (s; 3-C-Pz), 144.15 (s; 3-C-Pz),
139.14 (s; 5-C-Pz), 137.89 (s; 5-C-Pz), 129.34 (s; C6H5), 129.18 (s; C6H5),
128.57 (s; C6H5), 128.06 (s; C6H5), 125.70 (s; C6H5), 125.35 (s; C6H5),
105.99 (s; 4-C-Pz), 70.77 (s; thf), 25.01 (s; thf), 21.46 (s; CHSiMe3C6H5),
14.26 (s; 3-Me-Pz), 13.04 (s; 5-Me-Pz), 1.43 (s; SiMe3), À1.46 ppm (s;
SiMe3); elemental analysis calcd (%) for C36H50BClN7O2SiY: C 55.71,
H 6.49, N 12.63; found: C 55.96, H 6.63, N 12.41.
Synthesis of [TpMe2
YACHTUNGTRENNUNG(CH2Ph)ACHTUNGTERNN{GU (ArN)2CACHTUNTGRNEGU(N CH2Ph)}] (5, Ar=C6H3iPr2-2,6):
In a glove box, N,N’-2,6-diisopropylphenylcarbodiimide (BPC, 0.182 g,
0.50 mmol) was added to a solution of compound 1 (0.320 g, 0.50 mmol)
in THF (15 mL) at RT. The pale-yellow solution was stirred
X-ray data collection, structure determination, and refinement: Single
crystals of complexes 1–7 suitable for X-ray diffraction were sealed
under a nitrogen atmosphere in Lindemann glass capillaries for X-ray
structural analysis. Diffraction data were collected on a Bruker SMART
for 12 h. After removing the solvent under reduced pressure,
the residue was dissolved in toluene (8 mL). The solution was
layered with n-hexane to afford colorless crystals of com-
pound 5·C7H8. Yield: 0.460 g (90%); 1H NMR (400 MHz,
C6D6, RT): d=5.96–7.28 (m, 16H; C6H5 or C6H3), 5.63 (s,
1H; 4H-TpMe2), 5.30 (s, 2H; 4H-TpMe2), 3.95 (m, 2H; CH-
Table 1. Crystal and data-collection parameters of complexes 1, 2, and 3.
1
2
3·THF
formula
Mw
crystal color
crystal dimensions [mm]
crystal system
space group
a [ꢁ]
b [ꢁ]
c [ꢁ]
C33H44BN6OY
640.46
colorless
C60H88B4N24S4Y4
1672.66
colorless
0.20ꢂ0.12ꢂ0.10
cubic
C66H82B2N14O4Y2
1334.90
colorless
0.20ꢂ0.15ꢂ0.08
monoclinic
P21/c
22.118(7)
15.085(4)
21.202(6)
90.00
98.694(5)
90.00
1874.2(10)
4
1.268
1.706
0.15ꢂ0.10ꢂ0.06
triclinic
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG
¯
P1
Fd-3
10.771(4)
11.285(4)
16.001(6)
80.193(5)
81.410(4)
63.949(4)
1715.8(11)
2
24.966(6)
24.966(6)
24.966(6)
90.00
90.00
90.00
15562(6)
8
1.428
3.144
6848
A
ACHTUNGTRENNUNG
A
R
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
a [ꢁ]
B [8]
ACHTUNGTRENNUNG
NCN), 154.63 (s; 3-C-Pz), 149.78 (s; 3-C-Pz), 145.80 (s; 5-C-
Pz), 145.58 (s; 5-C-Pz), 143.64 (s; 5-C-Pz), 142.89(s; 5-C-Pz),
129.87 (s; C6H5 or C6H3), 128.54 (s; C6H5 or C6H3), 126.79 (s;
C6H5 or C6H3), 125.24 (s; C6H5 or C6H3), 125.15 (s; C6H5 or
C6H3), 124.51 (s; C6H5 or C6H3), 124.00 (s; C6H5 or C6H3),
117.21 (s; C6H5 or C6H3), 106.64 (s; 4-C-Pz), 56.42 (d, J-
g [8]
V [ꢁ3]
Z
1calcd [gcmÀ3
]
1.240
1.733
672
m [mmÀ1
F (000)
]
2784
ACHTUNGTRENNUNG(Y,C)=34 Hz; Y-CH2C6H5), 35.24 (s; (ArN)2CCH2Ph), 28.21
radiation
MoKa
MoKa
MoKa
(s; CHMe2), 25.40 (s; CHMe2), 25.30 (s; CHMe2), 14.38 (s; 3-
Me-Pz), 13.06 ppm (s; 5-Me-Pz); elemental analysis calcd (%)
for C61H78BN8Y: C 71.62, H 7.68, N 10.95; found: C 71.35,
H 7.56, N 11.14.
(l=0.710730 ꢁ)
T [K]
293(2)
293(2)
293(2)
scan type
w-2q
w-2q
w-2q
q range [8]
h,k,l range
2.02–25.10
À11<h<12
À13<k<12
À19<l<16
7107
1.41–25.58
À29<h<30
À30<k<30
À30<l<22
16425
1.64–25.01
À23<h<26
À17<k<9
À24<l<25
28471
CTHNUGTRNENUG YACHTUNGERTNNUNG a
Synthesis of [(TpMe2)2Y]+A[TpMe2 (N=C=CHPh)3]À(6): In
glove box, to a solution of compound 1 (0.320 g, 0.50 mmol)
in THF (15 mL) was dropwise added PhCH2CN (0.059 g,
0.5 mmol). After stirring for 24 h at ambient temperature, the
solution was concentrated to dryness under reduced pressure.
To the residue was added toluene (7 mL) and then n-hexane
was diffused into the concentrated toluene solution gave col-
orless crystals of compound 6. Yield: 0.167 g (70%, based on
the reaction stoichiometry); 1H NMR (400 MHz, [D8]THF,
RT): d=7.00–7.31 (m, 15H; C6H5), 5.94 (s, 3H; NCCHPh),
5.75 (s, 6H; 4H-TpMe2), 5.60 (s, 3H; 4H-TpMe2), 2.37 (br, 36H;
CH3 of TpMe2), 1.78 ppm (br, 18H; CH3 of TpMe2); 13C NMR
(100 MHz, [D8]THF, RT): d=206.02 (s; NCCHPh), 151.76 (s;
3-C-Pz), 145.93 (s; 5-C-Pz), 129.48 (s; C6H5), 128.72 (s; C6H5),
127.73 (s; C6H5), 120.42 (s; C6H5), 107.23 (s; 4-C-Pz), 91.95 (s;
NCCHPh), 13.70 (s; 3-Me-Pz), 13.24 ppm (s; 5-Me-Pz); ele-
mental analysis calcd (%) for C69H84B3N21Y2: C 58.45, H 5.97,
N 20.75; found: C 58.71, H 6.02, N 20.48.
total reflns
unique reflns
5953
1237
12297
[R
N
[R
A
[RACHTNGUTERN(UNG int)=0.1474]
completeness to q [%]
max transmission
97.4 (q=25.10)
0.9032,
100 (q=25.58)
0.7459,
99.9 (q=25.01)
0.8756,
min transmission
0.7811
0.5748
0.7266
refinement method
data/restraints/parameters
GOF on F2
full-matrix least-squares on F2
5953/1/382
0.977
1237/0/75
1.078
12297/19/786
1.002
final R indices [I>2s(I)]
R1 =0.0689
wR2 =0.1711
R1 =0.1438
wR2 =0.2144
0.896,
R1 =0.0323
wR2 =0.0848
R1 =0.0484
wR2 =0.0945
0.296,
R1 =0.0640
wR2 =0.0933
R1 =0.2150
wR2 =0.1138
0.764,
R indices (all data)
largest diff. peak
and hole [eꢁÀ3
]
À0.993
À0.244
À0.439
Chem. Eur. J. 2013, 19, 11975 – 11983
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
11981

J. Zhang, X. Zhou et al.
Apex CCD diffractometer by using
graphite-monochromated MoKa radia-
tion (l=0.71073 ꢁ). During the col-
lection of the intensity data, no sig-
nificant decay was observed. The in-
tensities were corrected for Lorentz-
polarization effects and empirical ab-
sorption by using the SADABS pro-
gram.[22] The structures were solved
by using direct methods with the
SHELXL-97 program.[23] All non-hy-
drogen atoms were located from the
difference Fourier syntheses. The
H atoms were included at calculated
positions with isotropic thermal pa-
rameters related to those of the sup-
porting C atoms, but were not includ-
ed in the refinement. All of the calcu-
lations were performed by using the
Bruker Smart program. The atomic
coordinates and equivalent isotropic
displacement parameters, including
all of the bond lengths and angles, as
well as the anisotropic displacement
parameters, are provided in the cif
files. The crystal data of compounds 6
Table 2. Crystal and data-collection parameters of complexes 4, 5, 6, and 7.
4
5·1/2C7H8
6
7
formula
Mw
crystal color
crystal dimensions [mm]
crystal system
space group
a [ꢁ]
b [ꢁ]
c [ꢁ]
C36H50BClN7O2SiY
776.09
colorless
C61H78BN8Y
1023.03
colorless
0.15ꢂ0.10ꢂ0.06
monoclinic
C2/c
41.320(11)
11.088(3)
25.297(7)
90.00
91.689(4)
90.00
11585(5)
8
1.173
1.051
C69H84B3N21Y2
1417.82
colorless
0.20ꢂ0.15ꢂ0.12
triclinic
P1
13.235(4)
16.875(5)
22.788(7)
77.708(5)
87.210(5)
68.371(4)
4620(3)
2
C55H71B2N17Y2
1169.73
colorless
0.18ꢂ0.12ꢂ0.08
triclinic
P1
12.740(5)
13.349(5)
21.247(8)
83.124(5)
75.276(6)
87.697(6)
3469(2)
2
1.120
1.708
1216
MoKa
293(2)
w-2q
1.54–25.00
À12<h<15
À15<k<15
À25<l<22
14486
12006
[RACHTNGUTERN(UNG int)=0.0682]
98.2 (q=25.00)
0.8755,
0.7486
0.15ꢂ0.10ꢂ0.08
triclinic
¯
¯
¯
P1
9.238(2)
11.125(3)
22.057(6)
95.400(3)
96.336(3)
113.859(3)
2036.3(9)
2
a [8]
b [8]
g [8]
V [ꢁ3]
Z
1calcd [gcmÀ3
]
1.266
1.566
812
1.019
1.293
1476
m [mmÀ1
F (000)
]
4352
radiation (l=0.710730 ꢁ)
T [K]
MoKa
293(2)
MoKa
293(2)
MoKa
293(2)
scan type
w-2q
w-2q
w-2q
q range [8]
h,k,l range
1.88–25.05
À10<h<10
À8<k<13
À24<l<26
8517
1.61–26.01
À50<h<45
À13<k<13
À31<l<27
25737
1.33–25.01
À15<h<14
À20<k<17
À27<l<24
19270
total reflns
and
7 show some high R values,
unique reflns
7066
11346
15951
owing to the poor crystal qualities. A
summary of the crystallographic data
and selected experimental informa-
tion are listed in Table 1 and Table 2.
[R
N
[R
A
[R
(int)=0.0647]
completeness to q [%]
max. and min.
98.0 (q=25.05)
0.8850,
99.4 (q=26.01)
0.9396,
97.9 (q=25.01)
0.8603,
transmission
0.7991
0.8583
0.7820
CCDC-923866 (1), CCDC-923868
(2), CCDC-923869 (3), CCDC-
923871 (4), CCDC-923867 (5),
CCDC-923865 (6), and CCDC-
923870 (7) contain the supplementary
crystallographic data for this paper.
These data can be obtained free of
charge from The Cambridge Crystal-
refinement method
data/restraints/parameters
GOF on F2
full-matrix least-squares on F2
7066/0/455
1.008
11346/0/647
0.871
15951/3/880
0.906
12006/0/688
0.948
final R indices
AHCTUNGTRENN[GUN I>2s (I)]
R indices (all data)
R1 =0.0510
wR2 =0.1054
R1 =0.0813
wR2 =0.1125
0.549,
R1 =0.0481
wR2 =0.0834
R1 =0.1168
wR2 =0.0978
0.489,
R1 =0.0941
wR2 =0.2065
R1 =0.2013
wR2 =0.3014
1.291,
R1 =0.0995
wR2 =0.2744
R1 =0.1752
wR2 =0.3119
1.573,
largest diff. peak
and hole [eꢁÀ3
]
À0.692
À0.433
À0.641
À1.207
lographic
Data
Centre
via
www.ccdc.cam.ac.uk/data_request/cif.
Acknowledgements
775; j) L. Zhang, M. Nishiura, M. Yuki, Y. Luo, Z. Hou, Angew.
Chem. 2008, 120, 2682; Angew. Chem. Int. Ed. 2008, 47, 2642; k) X.
Xu, Y. Chen, J. Sun, Chem. Eur. J. 2009, 15, 846; l) X. Li, M. Nish-
iura, L. Hu, K. Mori, Z. Hou, J. Am. Chem. Soc. 2009, 131, 13870;
m) G. Du, Y. Wei, L. Ai, Y. Chen, Q. Xu, X. Liu, S. Zhang, Z. Hou,
X. Li, Organometallics 2011, 30, 160.
We thank the NNSF, the NSFof Shanghai, the 973 Program
(2012CB821600), and the Shanghai Leading Academic Discipline Project
(B108) for financial support.
[1] For reviews, see: a) M. Nishiura, Z. Hou, Nat. Chem. 2010, 2, 257;
b) P. M. Zeimentz, S. Arndt, B. R. Elvidge, J. Okuda, Chem. Rev.
2006, 106, 2404; c) F. T. Edelmann in Comprehensive Organometallic
Chemistry III, Vol. 4.01 (Eds.: R. H. Crabtree, D. M. P. Mingos),
Elsevier, Oxford, 2006, p. 1.
[2] a) P. G. Hayes, W. E. Piers, R. McDonald, J. Am. Chem. Soc. 2002,
124, 2132; b) S. Bambirra, M. Bouwkamp, A. Meetsman, B. Hessen,
J. Am. Chem. Soc. 2004, 126, 9182; c) Y. Luo, J. Baldamus, Z. Hou,
J. Am. Chem. Soc. 2004, 126, 13910; d) L. Zhang, Y. Luo, Z. Hou, J.
Am. Chem. Soc. 2005, 127, 14562; e) X. Li, J. Baldamus, Z. Hou,
Angew. Chem. 2005, 117, 984; Angew. Chem. Int. Ed. 2005, 44, 962;
f) L. Zhang, T. Suzuki, Y. Luo, M. Nishiura, Z. Hou, Angew. Chem.
2007, 119, 1941; Angew. Chem. Int. Ed. 2007, 46, 1909; g) B. Wang,
D. Cui, K. Lv, Macromolecules 2008, 41, 1983; h) A. Ravasio, C.
Zampa, L. Boggioni, I. Tritto, J. Hitzbleck, J. Okuda, Macromole-
cules 2008, 41, 9565; i) M. Zimmermann, K. W. Tornroos, R. Anwan-
der, Angew. Chem. 2008, 120, 787; Angew. Chem. Int. Ed. 2008, 47,
[3] a) J. Cheng, T. Shima, Z. Hou, Angew. Chem. 2011, 123, 1897;
Angew. Chem. Int. Ed. 2011, 50, 1857; b) D. M. Lyubov, C. Dçing,
Y. S. Ketkov, R. Kempe, A. A. Trifonov, Chem. Eur. J. 2011, 17,
3824; c) M. Nishiura, J. Baldamus, T. Shima, K. Mori, Z. Hou,
Chem. Eur. J. 2011, 17, 5033; d) M. Ohashi, M. Konkol, I. D. Rosal,
R. Poteau, L. Maron, J. Okuda, J. Am. Chem. Soc. 2008, 130, 6920;
e) J. Cheng, K. Saliu, G. Y. Kiel, M. J. Ferguson, R. McDonald, J.
Takats, Angew. Chem. 2008, 120, 4988; Angew. Chem. Int. Ed. 2008,
47, 4910; f) X. Li, J. Baldamus, M. Nishiura, O. Tardif, Z. Hou,
Angew. Chem. 2006, 118, 8364; Angew. Chem. Int. Ed. 2006, 45,
8184; g) B. D. Ward, S. Bellemin-Laponnaz, L. H. Gade, Angew.
Chem. 2005, 117, 1696; Angew. Chem. Int. Ed. 2005, 44, 1668; h) S.
Arndt, K. Beckerle, P. M. Zeimentz, T. P. Spaniol, J. Okuda, Angew.
Chem. 2005, 117, 7640; Angew. Chem. Int. Ed. 2005, 44, 7473.
[4] a) J. Scott, F. Basuli, A. R. Fout, J. C. Huffman, D. J. Mindiola,
Angew. Chem. 2008, 120, 8630; Angew. Chem. Int. Ed. 2008, 47,
11982
www.chemeurj.org
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2013, 19, 11975 – 11983

À
Reactivity of Scorpionate-Anchored Yttrium Dialkyl Complexes
FULL PAPER
8502; b) E. Lu, Y. Li, Y. Chen, Chem. Commun. 2010, 46, 4469; c) J.
Chu, E. Lu, Z. Liu, Y. Chen, X. Leng, H. Song, Angew. Chem. 2011,
123, 7819; Angew. Chem. Int. Ed. 2011, 50, 7677; d) B. F. Wicker, H.
Fan, A. K. Hickey, M. G. Crestani, J. Scott, M. Pink, D. J. Mindiola,
J. Am. Chem. Soc. 2012, 134, 20081.
[13] There are no examples of tetranuclear cubane-like Ln4S4 complexes,
although two examples of lanthanide clusters that include Ln6S6
double-cubane cores have been reported: a) A. Kornienko, T. J.
Emge, G. A. Kumar, R. E. Riman, J. G. Brennan, J. Am. Chem. Soc.
2005, 127, 3501; b) L. Huebner, A. Kornienko, T. J. Emge, J. G.
Brennan, Inorg. Chem. 2005, 44, 5118.
[14] a) W. Yi, J. Zhang, M. Li, Z. Chen, X. Zhou, Inorg. Chem. 2011, 50,
11813; b) H. Wang, H. Li, Z. Xie, Organometallics 2003, 22, 4522;
c) H. Li, Y. Yao, Q. Shen, L. Weng, Organometallics 2002, 21, 2529.
[15] A sole example of C=S cleavage of phenyl isocyanate on a ditanta-
lum–dihydride complex that contains side-on- and end-on-bound di-
nitrogen has been reported: J. Ballmann, A. Yeo, B. O. Patrick,
M. D. Fryzuk, Angew. Chem. 2011, 123, 527; Angew. Chem. Int. Ed.
2011, 50, 507.
[5] a) W. Zhang, Z. Wang, M. Nishiura, Z. Xi, Z. Hou, J. Am. Chem.
Soc. 2011, 133, 5712; b) J. Hong, L. Zhang, X. Yu, M. Li, Z. Zhang,
P. Zheng, M. Nishiura, Z. Hou, X. Zhou, Chem. Eur. J. 2011, 17,
2130; c) M. Zimmermann, D. Rauschmaier, K. Eichele, K. W. Tçrn-
roos, R. Anwander, Chem. Commun. 2010, 46, 5346; d) R. Litlabø,
M. Zimmermann, K. Saliu, J. Takats, K. W. Tçrnroos, R. Anwander,
Angew. Chem. 2008, 120, 9702; Angew. Chem. Int. Ed. 2008, 47,
9560.
[6] a) S. Li, J. Cheng, Y. Chen, M. Nishiura, Z. Hou, Angew. Chem.
2011, 123, 6484; Angew. Chem. Int. Ed. 2011, 50, 6360; b) N. A. Si-
ladke, J. W. Ziller, W. J. Evans, J. Am. Chem. Soc. 2011, 133, 3507.
[7] a) J. Cheng, H. Wang, M. Nishiura, Z. Hou, Chem. Sci. 2012, 3,
2230; b) A. Venugopal, W. Fegler, T. P. Spaniol, L. Maron, J. Okuda,
J. Am. Chem. Soc. 2011, 133, 17574; c) J. Cheng, M. J. Ferguson, J.
Takats, J. Am. Chem. Soc. 2010, 132, 2; d) Y. Takenaka, T. Shima, J.
Baldamus, Z. Hou, Angew. Chem. 2009, 121, 8028; Angew. Chem.
Int. Ed. 2009, 48, 7888; e) T. Shima, Z. Hou, J. Am. Chem. Soc.
2006, 128, 8124; f) D. Cui, M. Nishiura, Z. Hou, Angew. Chem. 2005,
117, 981; Angew. Chem. Int. Ed. 2005, 44, 959; g) O. Tardif, D. Ha-
shizume, Z. Hou, J. Am. Chem. Soc. 2004, 126, 8080; h) D. Cui, O.
Tardif, Z. Hou, J. Am. Chem. Soc. 2004, 126, 1312.
[16] J. Zhang, R. Y. Ruan, Z. H. Shao, R. F. Cai, L. H. Weng, X. G.
Zhou, Organometallics 2002, 21, 1420.
[17] a) J. E. Bercaw, D. L. Davies, P. T. Wolczanskit, Organometallics
1986, 5, 443; b) R. Duchateau, C. T. van Wee, J. H. Teuben, Organo-
metallics 1996, 15, 2291; c) W. J. Evans, K. J. Forrestal, J. W. Ziller, J.
Am. Chem. Soc. 1998, 120, 9273; d) W. Yi, J. Zhang, Z. Chen, X.
Zhou, Organometallics 2012, 31, 7213.
[18] Z. Zhang, X. Bu, J. Zhang, R. Liu, X. Zhou, L. Weng, Organometal-
lics 2010, 29, 2111.
[19] A. Domingos, M. R. J. Elsegood, A. C. Hillier, G. Lin, S. Liu, I.
Lopes, N. Marques, G. H. Maunder, R. McDonald, A. Sella, J. W.
Steed, J. Takats, Inorg. Chem. 2002, 41, 6761.
[8] a) N. Marques, A. Sella, J. Takats, Chem. Rev. 2002, 102, 2137; b) S.
Trofimenko, Scorpionates: The Coordination Chemistry of Polypyra-
zolylborate Ligands, Imperial College Press, London, 1999.
[9] a) D. P. Long, P. A. Bianconi, J. Am. Chem. Soc. 1996, 118, 12453;
b) J. Blackwell, C. Lehr, Y. M. Sun, W. E. Piers, S. D. Pearce-Batch-
ilder, M. J. Zaworotko, V. G. Young, Can. J. Chem. 1997, 75, 702.
[10] a) F. Han, J. Zhang, W. Yi, Z. Zhang, J. Yu, L. Weng, X. Zhou,
Inorg. Chem. 2010, 49, 2793; b) W. Yi, J. Zhang, Z. Chen, X. Zhou,
Inorg. Chem. 2012, 51, 10631.
[20] a) D. P. Long, A. Chandrasekaran, R. O. Day, P. A. Bianconi, A. L.
Rheingold, Inorg. Chem. 2000, 39, 4476; b) P. J. Bailey, R. A. Coxall,
C. M. Dick, S. Fabre, L. C. Henderson, C. Herber, S. T. Liddle, A.
Parkin, S. Parsons, Chem. Eur. J. 2003, 9, 4820.
[21] H. Ahlbrecht, S. Fischer, Tetrahedron 1970, 26, 2837.
[22] G. M. Sheldrick, SADABS, A Program for Empirical Absorption
Correction, Gçttingen, Germany, 1998.
[23] G. M. Sheldrick, SHELXL-97, Program for the Refinement of the
Crystal Structure, University of Gçttingen, Germany, 1997.
[11] a) S. Bambirra, A. Meetsma, B. Hessen, Organometallics 2006, 25,
3454; b) W. Huang, B. M. Upton, S. I. Khan, P. L. Diaconescu, Orga-
nometallics 2013, 32, 1379.
[12] a) D. P. Mills, O. J. Cooper, J. McMaster, W. Lewis, S. T. Liddle,
Dalton Trans. 2009, 4547; b) A. J. Wooles, D. P. Mills, W. Lewis, A. J.
Blake, S. T. Liddle, Dalton Trans. 2010, 39, 500.
Received: February 17, 2013
Revised: June 14, 2013
Published online: July 19, 2013
Chem. Eur. J. 2013, 19, 11975 – 11983
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
11983