Deprotonation of β-diketiminate in sterically demanding β-(diketiminato)-lanthanide complexes: Influence of lanthanide metals

Article abstract of DOI:10.1002/ejic.201000759

Attempted synthesis of tris(β-diketiminato)lanthanide complexes [Ln(L^2,6-Me2)₃] (L^2,6-Me2 = [{N(C ₆H₃Me₂-2,6)C(Me)}₂-CH]) resulted in ligand deprotonation, and different outcomes depending on the central metal used were observed. Reaction of YbCl3 with NaL^2,6-Me2 (3 equiv.) afforded the fivemembered cyclometalated ytterbium β-diketiminate complex [Yb(L^2,6-Me2)(L^2,6-Me2)dep] (1). The same reaction with LnCl₃ (Ln = Nd, Sm, and Er) gave the new complexes composed of one normal L^2,6-Me2 and one deprotonated neighboring benzazacyclopentane ligand derived from deprotonation of the 2-methyl group followed by an attack of the carbon atom on the β-diketiminate backbone, [Ln(L^2,6-Me2)- (L^2,6-Me2)^dep′(thf)] [Ln = Nd (2), Sm (3), and Er (4)]. The bonding mode in the {Ln(L^2,6-Me2)^dep′} moiety was also found to depend on the central metal ions.

Full text of DOI:10.1002/ejic.201000759

FULL PAPER
DOI: 10.1002/ejic.201000759
Deprotonation of β-Diketiminate in Sterically Demanding β-(Diketiminato)-
lanthanide Complexes: Influence of Lanthanide Metals
Rui Jiao,[a] Mingqiang Xue,[a] Xiaodong Shen,[a] Yong Zhang,[a] Yingming Yao,[a] and
Qi Shen*[a,b]
Keywords: Lanthanide complexes / N ligands / Diketiminato ligand / Deprotonation / Metalation / Steric hindrance
2
Attempted synthesis of tris(β-diketiminato)lanthanide com-
posed of one normal L2,6-Me and one deprotonated neigh-
boring benzazacyclopentane ligand derived from deproton-
ation of the 2-methyl group followed by an attack of the
2,6-Me2
plexes [Ln(L2,6-Me )3] (L
= [{N(C6H3Me2-2,6)C(Me)}2-
2
CH]) resulted in ligand deprotonation, and different out-
comes depending on the central metal used were observed.
carbon atom on the β-diketiminate backbone, [Ln(L2,6-Me )-
2
Reaction of YbCl3 with NaL2,6-Me (3 equiv.) afforded the five-
(L2,6-Me
)
depЈ(thf)] [Ln = Nd (2), Sm (3), and Er (4)]. The bond-
2
2
membered cyclometalated ytterbium β-diketiminate com- ing mode in the {Ln(L2,6-Me
)
depЈ} moiety was also found to
2
2,6-Me2
plex [Yb(L2,6-Me )(L
)
dep] (1). The same reaction with
depend on the central metal ions.
2
LnCl3 (Ln = Nd, Sm, and Er) gave the new complexes com-
small (Yb), none of the metathesis reactions afforded the
Introduction
target complexes [Ln(L2,6-Me )3], but rather new complexes
2
Bidentate β-diketiminate monoanions have been widely
used as spectator ligands in coordination chemistry and or-
ganometallic chemistry of lanthanide metals.[1] These li-
gands have also been proven under certain conditions to
undergo transformations that include reduction to di- or
trianionic species by a reducing agent,[2] deprotonation to
a dianion by means of an alkane elimination[3a–e] or a β-
diketiminate elimination,[3f] and oxidation coupling to a
neutral molecule.[4] Recently we have reported that the β-
diketiminate group in a sterically demanding complex, such
as tris(β-diketiminato)lanthanide complex, can also serve as
an active species in homogeneous catalysis, and the activity
was found to depend both on the size of the β-diketiminato
ligands and the central metals.[5] These results encouraged
us to synthesize tris(β-diketiminato)lanthanide complexes
that contained one “normal” ligand and one deprotonated
ligand by a β-diketiminato ligand elimination. Moreover,
we observed different outcomes depending on the central
metal ions used: a cyclometalated complex [Yb(L2,6-Me )-
2
(L2,6-Me
)
dep] for Yb and the complexes with a neighboring
2
benzazacyclopentane ligand [Ln(L2,6-Me )(L
)
depЈ(thf)]
2,6-Me2
2
for Nd, Sm, and Er. Here we report the results.
Results and Discussion
Synthesis and Molecular Structure of Cyclometalated
2,6-Me2
Ytterbium(III) Complex [Yb(L2,6-Me )(L
)
dep] (1)
2
The tris(β-diketiminato)ytterbium complex with the
β-diketiminato ligand bearing one methyl group at the
with a bulky ligand L2,6-Me (L2,6-Me = [{N(C6H3Me2-2,6)-
C(Me)}2CH]) in an attempt to extend the synthesis and re-
active chemistry of tris(β-diketiminato)lanthanide com-
2
2
2-position on the phenyl ring, [Yb(L2-Me)3] (L2-Me
=
[{N(C6H4Me-2)C(Me)}2CH]), has recently been found to
plexes. The metathesis reactions of NaL2,6-Me with various
2
be stable.[5b] Thus, the reaction of YbCl3 with a more bulky
LnCl3 from early to late lanthanide metals (Nd, Sm, Er,
and Yb) were conducted in a molar ratio of 3 to 1 with the
aim of understanding the influence of the size of the metals.
However, no matter whether the metal was large (Nd) or
β-diketiminate sodium salt NaL2,6-Me was tested in THF
2
to see whether [Yb(L2,6-Me )3] could also be prepared. The
2
reaction proceeded well at 60 °C and gave the dark green
solution from which dark green crystals were obtained in
41% yield upon crystallization at room temperature. How-
ever, elemental analysis and single-crystal X-ray diffraction
determination demonstrated that the crystals were not the
[a] Key Laboratory of Organic Synthesis, College of Chemistry,
Chemical Engineering and Materials Science,
Dushu Lake Campus, Suzhou University,
Suzhou 215123, People’s Republic of China
Fax: +86-512-65880305
expected [Yb(L2,6-Me )3], but the cyclometalated ytter-
2
2,6-Me2
bium(III) complex [Yb(L2,6-Me )(L
)
dep] (1) instead.
2
E-mail: qshen@suda.edu.cn
Complex 1 contains both the monoanionic ligand L2,6-Me
2
[b] State Key Laboratory of Organometallic Chemistry,
Shanghai Institute of Organic Chemistry,
Chinese Academy of Sciences,
and its deprotonation partner (L2,6-Me
)
by the elimi-
dep
2
Shanghai 200032, People’s Republic of China
nation of one β-diketiminato ligand (Scheme 1).
1448
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2011, 1448–1453

Deprotonation of β-Diketiminate
groups activated by a Yb···Me agostic interaction. An at-
2,6-Me2
tempt to isolate the intermediate [{Yb(L2,6-Me )2}(L
)]
2
was unsuccessful.
The molecular structure of 1 is illustrated in Figure 1.
The selected bond lengths and angles are listed in Table 1.
The central Yb ion bonded to N1 and N2 from a
monoanionic L2,6-Me , thereby forming a boat-shaped β-di-
2
ketiminate ytterbium moiety, and to the bicyclic ligand
through N3, N4, and C41. The bonding mode in the
{Yb(L2,6-Me )} part is close to η , which is similar to that
5
2
Scheme 1.
in reported [Yb(LЈ)(LЈ)dep],[3f] and the bond parameters in
{Yb(L2,6-Me )} are comparable with the corresponding data
2
in η5-bonded complexes of [Yb(LЈ)(LЈ)dep [3f]
and [Yb{N-
]
(SiMe3)C(C6H4Me-4)C(H)C(adamantyl-1)N(SiMe3)}2].[6]
Further experiments indicated that a monochloride de-
rivative [Yb(L2,6-Me )2Cl] could be isolated when YbCl3 was
2
In the {Yb(L2,6-Me
)
dep} part, the Yb atom is coordinated
2
treated with NaL2,6-Me in a molar ratio of 1 to 2. These
2
by the novel bianionic ligand [(L2,6-Me
)
]
through two
dep 2–
2
results demonstrated that the synthesis of tris(β-diketimin-
ato)lanthanide complexes is very sensitive to the size of the
β-diketiminato ligand. Addition of the second methyl group
nitrogen atoms (N3 and N4) and one carbon atom (C41).
The Yb–C41 bond length of 2.380(3) Å is 0.026 Å shorter
than 2.406 Å in [Yb(LЈ)(LЈ)dep],[3f] which may be due to the
requirement of weak interactions between the two aromatic
carbon atoms (C35 and C36), respectively, to Yb. The Yb–
N4 bond length of 2.291(3) Å is consistent with 2.289(2) Å
in [Yb(LЈ)(LЈ)dep].[3f] The distances of Yb···C35 [2.858(3) Å]
and Yb···C36 [2.788(3) Å] are in the range observed in the
other known complexes of lanthanide π-arene interac-
tions.[7]
at the 6-position on
a
phenyl ring led to an
L2,6-Me ligand that was too bulky to stabilize the tris(β-
diketiminato)ytterbium complex.
2
The self-deprotonation reaction of the β-diketiminato li-
gand was first reported in the case of the reaction of
[Pb(LЈ)2] with [Yb(LЈ)2] (LЈ = [{N(SiMe3)C(Ph)}2CH]). The
reaction led to a four-membered cyclometalated ytter-
bium(III) β-diketiminate complex, [Yb(LЈ)(LЈ)dep].[3f] In our
case, the five-membered cyclometalated ytterbium was
formed because of the presence of an ortho-methyl group at
the phenyl ring. According to the pathway suggested for the
synthesis of [Yb(LЈ)(LЈ)dep],[3f] complex 1 may be formed
2,6-Me2
through an unstable intermediate [{Yb(L2,6-Me )2}(L
)]
2
as shown in Scheme 2.
Figure 1. ORTEP diagram of 1 showing the atom-numbering
scheme. Thermal ellipsoids are drawn at the 10% probability level.
Hydrogen atoms are omitted for clarity.
Syntheses and Molecular Structures of [Ln(L2,6-Me )-
2
Scheme 2.
(L2,6-Me
)
depЈ(thf)] [Ln = Nd (2), Sm (3), and Er (4)]
2
The reaction first afforded an unstable transient interme-
The same reaction with a large metal chloride, NdCl3,
2,6-Me2
diate [{Yb(L2,6-Me )2}(L
)]. On account of the over- was then tried to address the influence of the size of metal.
2
crowded coordination environment around the central Yb Treatment of NdCl3 with NaL2,6-Me (3 equiv.) at 60 °C gave
metal by three β-diketiminato ligands, the third loosely at- the yellow-green crystals from a mixture of THF and hex-
2
tached ligand L2,6-Me deprotonated one of the methyl ane. The full characterization of the crystals, including X-
2
Eur. J. Inorg. Chem. 2011, 1448–1453
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1449

R. Jiao, M. Xue, X. Shen, Y. Zhang, Y. Yao, Q. Shen
FULL PAPER
Table 1. Selected bond lengths [Å] and bond angles [°] for complex 1.
Yb1–N1
2.297(3)
Yb1–N2
2.283(3)
Yb1–N3
2.286(3)
Yb1–N4
Yb1–C4
Yb1–C41
N3–C23
C3–C4
2.291(3)
2.951(3)
2.380(3)
1.354(4)
1.405(5)
1.418(5)
84.51(10)
113.72(10)
69.88(11)
112.5(3)
Yb1–C2
Yb1–C35
N1–C2
N4–C35
C23–C24
C36–C41
N1–Yb1–N3
N2–Yb1–N4
C35–N4–Yb1
C35–C36–C41
2.962(3)
2.858(3)
1.328(4)
1.435(4)
1.379(5)
1.462(5)
133.00(10)
93.46(10)
97.47(19)
118.7(3)
Yb1–C3
Yb1–C36
N2–C4
C2–C3
C24–C25
3.048(4)
2.788(3)
1.333(4)
1.409(5)
1.419(5)
C35–C36
N1–Yb1–N2
N2–Yb1–N3
N4–Yb1–C41
C36–C35–N4
N1–Yb1–N4
N3–Yb1–N4
C36–C41–Yb1
146.08(9)
78.58(10)
89.8(2)
ray crystal structure determination, revealed the crystals to molecule. The bond parameters in the {LnL2,6-Me } part of
2
2,6-Me2
be a deprotonated complex, [Nd(L2,6-Me )(L
)
depЈ(thf)] each complex are highly comparable to those found in the
2
(2), not the [Nd(L2,6-Me )3] complex. The occurrence of the corresponding [Ln(L4-Me)3].[5]
2
deprotonation reaction here indicates that even with a large
metal (Nd), the ligand L2,6-Me is still too big to form stable
2
[Nd(L2,6-Me )3]. Complex 2 has a new structural skeleton
2
that contains one normal L2,6-Me and one neighboring
2
benzazacyclopentane ligand derived from deprotonation of
the 2-methyl group followed by an attack of the carbon
atom on the β-diketiminate backbone as shown in
Scheme 3.
2,6-Me2
Figure 2. ORTEP diagram of [Ln(L2,6-Me )(L
)
depЈ(thf)] [Ln =
2
Scheme 3.
Nd (2), Sm (3), Er (4)] showing the atom-numbering scheme ther-
mal ellipsoids are drawn at the 10% probability level. Hydrogen
The formation of a new Nd complex 2 prompted us to atoms are omitted for clarity.
further study the reactions with other lanthanide metal
chlorides. Thus, reactions of NaL2,6-Me with middle and
However, differences in bonding mode in the {Ln-
2
later metal chlorides, SmCl3 and ErCl3, were conducted in (L2,6-Me
)
depЈ} part were observed among them. In com-
2
THF at 60 °C. Red and dark-brown crystals, respectively, plexes 2 and 3, the novel ligand can be best described as
were isolated in good yields. Both crystals were charac- implicating η3-1-azaallyl (N3–C23–C24) and amide (N4)
terized by X-ray diffraction to be the corresponding com- bonds to the metals. The distances of Ln···C23 and
2,6-Me2
plexes [Sm(L2,6-Me )(L
)
depЈ(thf)] (3) and [Er(L2,6-Me2)- Ln···C24 are 2.859(7) and 3.001(7) Å for Nd, and 2.932(9)
2
(L2,6-Me
)
depЈ(thf)] (4), which are analogues of complex 2 and 3.110(9) Å for Sm, respectively, which are in the range
2
(Scheme 3). The formation of 2–4 may be attributed to the of intramolecular π-arene···Ln interactions. In complex 2, a
absence of an Ln···Me agostic interaction in their interme- weak interaction between Nd and C25 was also observed
diates.
because the distance of Nd···C25 is 3.093(7) Å; subtraction
Complexes 2–4 are sensitive to air and moisture but of an extrapolated radius (0.983 Å) for six-coordinate Nd3+
thermostable. They decomposed at 127–129, 123–124, and from Nd···C gives 2.11 Å, well within the upper limit
90–93 °C, respectively.
(2.16 Å) for significant intramolecular π-arene···Ln interac-
Complexes 2–4 all contain a coordinated thf molecule. tions.[8] The distance of Sm···C25 is longer than the upper
Their molecular structures are shown in Figure 2. The se- value of π-arene···Ln bonding.
In complex 4, the {Er(L2,6-Me
)
depЈ} moiety can be best
2
lected bond lengths and angles are listed in Table 2. The
central metal in each complex is coordinated by one described as η2-1,5 diazapentene-2 (N3, N4) bonds to the
monoanionic β-diketiminato ligand L2,6-Me in a chelating metal. The distance of Er···C23 is 2.965(6) Å, thus indicat-
2
mode through two nitrogen atoms (N1 and N2), one dian- ing the presence of a C23···Er interaction. But the distance
ionic neighboring benzazacyclopentane ligand, and one thf of Er···C24 [3.171(6) Å] is far from the limit value for a
1450
www.eurjic.org
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2011, 1448–1453

Deprotonation of β-Diketiminate
Table 2. Selected bond lengths [Å] and bond angles [°] for complexes 2–4.
2
3
4
2
3
4
Ln1–N1
Ln1–N3
Ln1–O1
Ln1–C24
N2–C4
N4–C25
C2–C3
C23–C24
2.471(8)
2.293(8)
2.526(5)
3.110(9)
1.342(10)
1.499(13)
1.387(13)
1.363(14)
1.526(14)
1.512(18)
76.6(2)
2.536(6)
2.349(6)
2.581(5)
3.001(7)
1.328(9)
1.504(9)
1.397(10)
1.363(10)
1.571(10)
1.496(11)
75.27(18)
95.4(2)
2.392(4)
2.215(5)
2.426(3)
3.171(6)
1.339(7)
1.516(8)
1.390(8)
1.334(8)
1.542(8)
1.501(10)
79.26(15)
98.43(19)
136.84(16)
90.59(14)
85.65(14)
107.1(5)
Ln1–N2
Ln1–N4
Ln1–C23
N1–C2
N3–C23
N4–C35
C3–C4
2.487(6)
2.231(7)
2.932(9)
1.339(12)
1.376(11)
1.402(13)
1.396(13)
1.530(16)
1.431(14)
2.489(6)
2.291(6)
2.859(7)
1.333(9)
1.407(9)
1.394(9)
1.415(10)
1.518(10)
1.404(10)
2.394(4)
2.180(4)
2.965(6)
1.350(7)
1.413(7)
1.396(7)
1.396(8)
1.524(8)
1.423(9)
C24–C25
C35–C36
C25–C41
C36–C41
N1–Ln1–N2
N4–Ln1–N3
N3–Ln1–N1
N4–Ln1–O1
N1–Ln1–O1
N4–C25–C41
C36–C41–C25
C35–C36–C41
N3–Ln1–N2
N4–Ln1–N1
N4–Ln1–N2
N3–Ln1–O1
N2–Ln1–O1
C35–N4–C25
N4–C35–C36
96.6(2)
124.0(3)
99.1(2)
113.8(2)
127.94(19)
100.8(2)
82.97(19)
160.82(19)
97.69(15)
124.57(17)
100.96(15)
90.78(15)
164.46(15)
97.6(3)
138.3(3)
92.9(2)
134.45(19)
85.98(18)
86.37(18)
109.2(6)
93.0(2)
87.2(2)
163.4(2)
107.0(8)
111.3(11)
104.4(10)
103.3(9)
107.1(9)
indicator and a hexamine buffer.[11] Carbon, hydrogen, and nitro-
gen analyses were performed by direct combustion using a Carlo–
Erba EA-1110 instrument. The IR spectra were recorded with a
Nicolet-550 FTIR spectrometer as KBr pellets. The uncorrected
melting points of crystalline samples were determined in sealed Ar-
filled capillaries.
weak π-arene···Ln interaction. The differences in bonding
mode observed among the three complexes may be attrib-
uted to the differences in the amount of steric hindrance
around the central metals that results from the size of met-
als: the smallest ionic radius of Er leads to the most
crowded coordinated sphere. The bond lengths of C25–C41
2,6-Me2
in 2–4 are highly comparable to each other and are consis- [Yb(L2,6-Me )(L
)
dep] (1): The solution of NaL2,6-Me2 in THF
2
(15.7 mL, 8.70 mmol) that was formed by the reaction of NaH with
tent with the value of a C–C single bond.
L2,6-Me H in THF at room temperature was added to a slurry of
2
anhydrous YbCl3 (0.81 g, 2.90 mmol) in THF (about 10 mL). The
reaction mixture was stirred at 60 °C for 24 h. The undissolved por-
tion was removed by centrifugation and the dark green solution
was concentrated to about 1 mL. Hexane (5 mL) was then added.
The solution was cooled to –10 °C for crystallization to give dark
green crystals in 41% (0.96 g) yield; m.p. 72–75 °C (decomp.). IR
Conclusion
The reaction of LnCl3 (Ln = Nd, Sm, Er, and Yb) with
NaL2,6-Me (3 equiv.) leads to the sterically induced self-de-
2
(KBr): ν = 3046 (w), 3019 (w), 2916 (m), 2853 (w), 1659 (m), 1624
˜
protonation of L2,6-Me with the formation of novel com-
2
(s), 1553 (s), 1468 (s), 1379 (m), 1277 (m), 1182 (m), 1092 (m), 1028
(w), 988 (w), 918 (w), 766 (s), 694 (w), 596 (w), 569 (w), 520 (w),
484 (w), 440 (w) cm–1. C42H49N4Yb (782.89): calcd. C 64.43, H
6.31, N 7.16, Yb 22.10; found C 63.63, H 6.67, N 6.71, Yb 21.96.
plexes 1–4. The structural motif of 1–4 depends on the lan-
thanide metals: the cyclometalated β-diketiminate complex
for the smallest metal Yb, and the complexes [Ln-
2,6-Me2
(L2,6-Me )(L
)
depЈ(thf)] with a neighboring benzazacy-
2
2,6-Me2
[Nd(L2,6-Me )(L
)
depЈ(thf)] (2): Complex 2 was prepared by the
2
clopentane partner for Nd, Sm, and Er. Moreover, the in-
same procedure as that for complex 1, but anhydrous NdCl3
fluence of lanthanide metals on the bonding mode in the
(0.72 g, 2.87 mmol) in THF (about 10 mL) and the solution of
NaL2,6-Me (28.2 mL, 8.61 mmol) in THF were used. The yellow-
{Ln(L2,6-Me
)
depЈ} moiety for complexes 2–4 was also ob-
2
2
green crystals of complex 2 from a mixture of THF (1 mL) and
hexane (4 mL) were isolated at 5 °C in 71% (1.68 g) yield; m.p.
served. Further study of the reactivity of β-diketiminate in
sterically demanding lanthanide complexes continues in our
laboratory.
127–129 °C. IR (KBr): ν = 3017 (s), 2963 (s), 2918 (s), 2855 (s),
˜
1653 (s), 1624 (s), 1597 (s), 1552 (s), 1466 (s), 1379 (s), 1273 (s),
1091 (m), 1026 (m), 984 (w), 921 (w), 764 (s), 631 (w), 526 (w), 448
(w) cm–1. C46H57N4NdO (826.20): calcd. C 66.87, H 6.95, N 6.78,
Nd 17.46; found C 66.22, H 6.86, N 6.76, Nd 16.99.
Experimental Section
2,6-Me2
[Sm(L2,6-Me )(L
)
depЈ(thf)] (3): By the same procedure as that
2
General Procedures: All manipulations were performed under a
purified argon atmosphere using standard Schlenk techniques. Sol-
vents were degassed and distilled from sodium benzophenone ketyl
for complex 2, red crystals of complex 3 were obtained from the
treatment of SmCl3 (1.30 g, 5.06 mmol) with NaL2,6-Me (25.8 mL,
2
15.18 mmol) upon crystallization from a mixture of (about 1 mL)
and hexane (4 mL) at 5 °C; yield 1.90 g, 45%; m.p. 123–124 °C. IR
before use. L2,6-Me H was prepared according to the literature
2
method.[9] Anhydrous LnCl3 was prepared according to the litera-
ture procedure.[10] Lanthanide analyses were performed by ethyl-
enediaminetetraacetic acid (EDTA) titration with a xylenol orange
(KBr): ν = 2963 (w), 2912 (w), 2851 (w), 1660 (m), 1624 (s), 1553
˜
(s), 1469 (m), 1373 (m), 1276 (m), 1091 (m), 1026 (w), 997 (w), 804
(w), 765 (s), 631 (m), 517 (m), 448 (w) cm–1. C46H57N4OSm
Eur. J. Inorg. Chem. 2011, 1448–1453
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1451

R. Jiao, M. Xue, X. Shen, Y. Zhang, Y. Yao, Q. Shen
FULL PAPER
Table 3. Crystallographic data for complexes 1–4.
1
2·C4H8O
3
4
Empirical formula
Formula weight
T [K]
Crystal system
Space group
Crystal size [mm3]
a [Å]
C42H49N4Yb
782.89
223(2)
monoclinic
P21/n
0.70ϫ0.50ϫ0.40
11.7812(9)
14.8560(11)
20.9300(16)
93.581(2)
3656.0(5)
4
C50H65N4O2Nd
898.30
223(2)
monoclinic
C2/c
0.60ϫ0.12ϫ0.10
28.705(2)
20.7724(12)
20.8219(17)
132.4560(10)
9160.0(12)
8
C46H57N4OSm
832.31
293(2)
orthorhombic
Pbcn
0.60ϫ0.58ϫ0.30
18.2397(15)
11.6238(9)
38.654(4)
90
C46H57N4OEr
849.22
223(2)
orthorhombic
Pbcn
0.30ϫ0.30ϫ0.20
18.0005(10)
11.4813(8)
38.644(2)
90
b [Å]
c [Å]
β [°]
V [Å3]
8195.3(12)
8
1.349
7986.5(9)
8
1.413
Z
Dcalcd. [mgcm–3]
1.422
2.592
1.303
1.175
μ [mm–1]
1.472
2.141
F (000)
θ range [°]
Reflections collected/unique
R(int)
1596
3752
3448
3496
3.02–25.50
18377/6776
0.0274
3.05–25.50
23456/8515
0.0581
3.03–25.35
54769/7324
0.0736]
3.06–25.50
21992/7350
[0.0437
Data/restraints/parameters
Goodness-of-fit on F2
final R [IϾ2σ(I)]
wR2 (all data)
6776/0/436
1.116
0.0287
8515/12/487
1.130
0.0737
7324/1/421
1.178
0.0858
7350/1/481
1.165
0.0515
0.0629
0.1701
0.2187
0.0948
(832.31): calcd. C 66.38, H 6.90, N 6.73, Sm 18.06; found C 66.85,
H 6.92, N 6.73, Sm 17.90.
Acknowledgments
2,6-Me2
[Er(L2,6-Me )(L
)
depЈ(thf)] (4): By the same procedure as that
2
We are grateful to the National Natural Science Foundation of
China (NSFC) for financial support (grant numbers 20632040 and
20972107).
for complex 2, the dark brown crystals of complex 4 were obtained
from the treatment of ErCl3 (0.46 g, 1.68 mmol) with NaL2,6-Me
2
(16.5 mL, 5.04 mmol) upon crystallization from a mixture of THF
(about 1 mL) and hexane (4 mL) at 15 °C; yield 0.57 g, 40%; m.p.
[1] a) L. Bourget-Merle, M. F. Lappert, J. R. Severn, Chem. Rev.
2002, 102, 3031–3065; b) W. E. Piers, D. J. H. Emslie, Coord.
Chem. Rev. 2002, 131, 233–234; c) V. C. Gibson, K. Spitz-
messer, Chem. Rev. 2003, 103, 283–315; d) L. M. Mirica, X.
Ottenwaelder, T. D. P. Stack, Chem. Rev. 2004, 104, 1013–1046;
e) G. W. Coates, D. R. Moore, Angew. Chem. 2004, 116, 6784;
Angew. Chem. Int. Ed. 2004, 43, 6618–6639.
[2] a) A. G. Avent, A. V. Khvostov, P. B. Hitchcock, M. F. Lap-
pert, Chem. Commun. 2002, 1410–1411; b) O. Eisenstein, P. B.
Hitchcock, A. V. Khvostov, M. F. Lappert, L. Maron, L. Per-
rin, A. V. Protchenko, J. Am. Chem. Soc. 2003, 125, 10790–
10791; c) A. G. Avent, P. B. Hitchcock, A. V. Khvostov, M. F.
Lappert, A. V. Protchenko, Dalton Trans. 2004, 2272–2280.
[3] a) Y. Ding, H. Hao, H. W. Roesky, M. Noltemeyer, H. G.
Schmidt, Organometallics 2001, 20, 4806–4811; b) A. M. Necu-
lai, H. W. Roesky, D. Neculai, J. Magull, Organometallics 2001,
20, 5501–5503; c) S. Harder, Angew. Chem. 2003, 115, 3553;
Angew. Chem. Int. Ed. 2003, 42, 3430–3434; d) P. G. Hayes,
W. E. Piers, L. W. M. Lee, L. K. Knight, M. Parvez, M. R. J.
Elsegood, W. Clegg, Organometallics 2001, 20, 2533–2544; e)
F. Bazuli, J. C. Huffman, D. J. Mindiola, Inorg. Chem. 2003,
42, 8003–8010; f) P. B. Hitchcock, M. F. Lappert, A. V. Prot-
chenko, Chem. Commun. 2005, 951–953.
90–93 °C. IR (KBr): ν = 3018 (w), 2963 (m), 2916 (m), 2855 (w),
˜
1659 (s), 1624 (s), 1597 (s), 1553 (s), 1468 (s), 1369 (s), 1279 (m),
1184 (m), 1092 (m), 1032 (w), 766 (s), 635 (w), 519 (w), 421 (m)
cm–1. C46H57ErN4O (849.22): calcd. C 65.06, H 6.77, N 6.60, Er
19.72; found C 64.52, H 6.69, N 6.73, Er 19.33.
X-ray Crystallography: Suitable single crystals of complexes 1–4
were sealed in a thin-walled glass capillary, respectively, for de-
termining the single-crystal structure. Intensity data were collected
with a Rigaku Mercury CCD area detector in ω scan mode by
using Mo-Kα radiation (λ = 0.71070 Å). The diffracted intensities
were corrected for Lorentz polarization effects and empirical ab-
sorption corrections. Details of the intensity data collection and
crystal data are given in Table 3.
The structures were solved by direct methods and refined by full-
matrix least-squares procedures based on |F|2. All the non-hydrogen
atoms were refined anisotropically. The hydrogen atoms in these
complexes were all generated geometrically (C–H bond lengths
fixed at 0.95 Å), assigned appropriate isotropic thermal parameters,
and allowed to ride on their parent carbon atoms. All the H atoms
were held stationary and included in the structure factor calcula-
tion in the final stage of full-matrix least-squares refinement. The
structures were solved and refined by using SHELEXL-97 pro-
gram.
[4] R. Jiao, X. D. Shen, M. Q. Xue, Y. Zhang, Y. M. Yao, Q. Shen,
Chem. Commun. 2010, 46, 4118–4120.
[5] a) M. Q. Xue, R. Jiao, Y. Zhang, Y. M. Yao, Q. Shen, Eur. J.
Inorg. Chem. 2009, 4110–4118; b) R. Jiao, M. Q. Xue, X. D.
Shen, Y. Zhang, Y. M. Yao, Q. Shen, Eur. J. Inorg. Chem. 2010,
2523–2529.
CCDC-783856 (for 1), -783857 (for 2), -783858 (for 3), and -783859
(for 4) contain the supplementary crystallographic data for this
paper. These data can be obtained free of charge from The Cam-
bridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
[6] A. G. Avent, P. B. Hitchcock, A. V. Khvostov, M. F. Lappert,
A. V. Protchenko, Dalton Trans. 2003, 1070–1075.
[7]
a) H. Liang, Q. Shen, J. Guan, Y. Lin, J. Organomet. Chem.
1994, 474, 113–116; b) H. Liang, J. Guan, Y. Lin, Q. Shen,
1452
www.eurjic.org
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2011, 1448–1453

Deprotonation of β-Diketiminate
Youji Huaxue 1994, 14, 380–382; c) M. Niemeyer, S.-O. [10] M. D. Taylor, C. P. Carter, J. Inorg. Nucl. Chem. 1962, 24, 387–
Hauber, Z. Anorg. Allg. Chem. 1999, 625, 137–140; d) M. N.
Bochkarev, Chem. Rev. 2002, 102, 2089–2118.
[8] G. B. Deacon, Q. Shen, J. Organomet. Chem. 1996, 511, 1–17.
[9] J. Feldman, S. J. Mclain, A. Parthasarathy, W. J. Marshall, J. C.
Calabrese, S. D. Arthur, Organometallics 1997, 16, 1514–1516.
391.
[11] J. L. Atwood, W. E. Hunter, A. L. Wayda, W. J. Evans, Inorg.
Chem. 1981, 20, 4115–4119.
Received: July 12, 2010
Published Online: February 15, 2011
Eur. J. Inorg. Chem. 2011, 1448–1453
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1453