Unprecedented reaction of bridged bis(guanidinate) lanthanide complexes: Sterically induced deprotonation

Article abstract of DOI:10.1039/c3dt32882a

Reaction of LnCl₃ with a lithium salt of bridged bis(guanidinate) bearing a rigid naphthalene linker [Li₂{LH ₂}₂Li₂] (LH₂ = 1,8-C ₁₀H₆{NC(NⁱPr)(NHⁱPr)}₂) (1), which was synthesized by the reaction of 1,8-diaminonaphthalene with 2 equiv. of ⁿBuLi, followed by treatment with 2 equiv. of N,N′-diisopropylcarbodiimide, yielded the chlorides [LnCl{LH₂}] (Ln = Yb (2), Y (3)) in good yields. Metathesis reaction of 2 and 3 with NaN(SiMe₃)₂ did not afford the corresponding amide complexes, but the deprotonation products of [Ln{LH}]₂ (LH = 1,8-C₁₀H₆{NC(NⁱPr)(NHⁱPr)}{NC(N ⁱPr)₂}; Ln = Yb (4), Y (5)) were isolated instead. The LH in 4 and 5 both act as a bridging ligand binding to two metals in a μ-η¹:η²:η² fashion, and the re-arrangement of LH occurred during the reaction. The size of the amido group was found to have a great influence on the outcome of the metathesis reaction. Reaction of 2 with bulky NaNH(C₆H₃ⁱPr ₂-2,6) afforded 4 as the only product, whereas the same reaction with less bulky LiNH(C₆H₄Cl-4) and LiNH(C₆H ₄CH₃-4) led to the corresponding amides, [Yb{LH ₂}(NHC₆H₄Cl-4)]₂ (6) and [Yb{LH ₂}(NHC₆H₄CH₃-4)]₂ (7), respectively. The re-arrangement of ligands was also observed in both cases. A possible pathway for the deprotonation of LH₂ was discussed. Molecular structures of 1-7 were determined by X-ray single crystal analysis. The Royal Society of Chemistry 2013.

Full text of DOI:10.1039/c3dt32882a

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Proofs to: Prof. Qi Shen
College of Chemistry, Chemical
Engineering and Materials Science
Dushu Lake Campus
5
Soochow University
Suzhou, 215123, P. R. China
Fax. No.: (86)512ꢀ65880305
Tel. No.: (86)512ꢀ65882806
Eꢀmail: qshen@suda.edu.cn
10
Unprecedented reaction of bridged bis(guanidinate) lanthanide
complexes: Sterically induced deprotonation
15
Chuanyong Wang, Xingmin Zhang, Mingqiang Xue,* Yong Zhang and Qi Shen*
Key Laboratory of Organic Synthesis of Jiangsu Province, Department of Chemistry, Chemical Engineering and
Materials Science, Dushu Lake Campus, Soochow University, Suzhou 215123, People’s Republic of China
20
* To whom correspondence should be addressed. Email: qshen@suda.edu.cn; xuemingqiang@suda.edu.cn
1

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Unprecedented reaction of bridged bis(guanidinate) lanthanide
complexes: Sterically induced deprotonation
Chuanyong Wang, Xingmin Zhang, Mingqiang Xue,* Yong Zhang and Qi Shen*
5
10
15
Reaction of LnCl3 with lithium salt of bridged bis(guanidinate) bearing a rigid naphthalene linker
[Li2{LH2}2Li2] (LH2 = 1,8ꢀC10H6{NC(NiPr)(NHiPr)}2) (1), which was synthesized by the reaction of 1,8ꢀ
diaminonaphthalene with 2 equiv of nBuLi, followed by treatment with 2 equiv of N,N′ꢀ
diisopropylcarbodiimide, yielded the chlorides [LnCl{LH2}] (Ln = Yb (2), Y (3)) in good yields.
Metathesis reaction of 2 and 3 with NaN(SiMe3)2 did not afford the corresponding amide complexes, but
the deprotonation products of [Ln{LH}]2 (LH = 1,8ꢀC10H6{NC(NiPr)(NHiPr)}{NC(NiPr)2}; Ln = Yb (4),
Y (5)) were isolated instead. The LH in 4 and 5 both act as a bridging ligand binding to two metals in a ꢁꢀ
η1:η2:η2 fashion, and the reꢀarrangement of LH occurred during the reaction. The size of the amido group
was found to have a great influence on the outcome of the metathesis reaction. Reaction of 2 with bulky
i
NaNH(C6H3 Pr2ꢀ2,6) afforded 4 as the only product, whereas the same reaction with less bulky
LiNH(C6H4Clꢀ4) and LiNH(C6H4CH3ꢀ4) led to the corresponding amides, [Yb{LH2}(NHC6H4Clꢀ4)]2 (6)
and [Yb{LH2}(NHC6H4CH3ꢀ4)]2 (7), respectively. The reꢀarrangement of ligand was also observed in both
cases. A possible pathway for the deprotonation of LH2 was discussed. Molecular structures of 1ꢀ7 were
determined by Xꢀray single crystal analysis.
20
Introduction
Monoanionic guanidinate groups, as one of the important nonꢀcyclopentadienyl ligands, have been widely
used in organolanthanide chemistry as ancillary ligands, due to their strong binding to the lanthanide
metals and tunable electronic and steric factors.1 The N,N′,N″ꢀtrialkylguanidinates in these monoanionic
ligand sets are of interest because they can transfer to highly reactive dianionic species under certain
2

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conditions.2ꢀ6 For example, the dianionic guanidinate metal complexes react facilely with Me3SiCl to yield
a Me3Siꢀ modified monoanionic guanidinate complexes,4d,7 and the dianionic guanidinate Ti complex was
found not only to react with amine leading to an imido complex via deꢀguanidine, but also as an active
species for addition of amines to carbodiimides to guanidines.8 Till now several routes to dianionic
guanidinate species have been explored. They are cycloaddition of transition metal imido complexes with
carbodiimides,2 the reaction of [PtCl2(cod)] with N,N′,N″ꢀtriphenylguanidine,3 and the deprotonation
reaction of a coordinated monoanionic guanidinate using alkyl or amido metal reagents,4 or by either
guanidine elimination,5 or amine elimination.6 Here we report the first example of sterically induced
deprotonation of a coordinated bridged bis(guanidinate) ligand in lanthanide complexes, which leads to
the formation of bridged (monoꢀ and dianionic)guanidinate lanthanide complexes, and their reactivity
towards aromatic amines NH2Ar (Ar = C6H4Clꢀ4 and C6H4CH3ꢀ4) to binuclear bridged bis(monoanionic
guanidinate) lanthanide amides. The syntheses of the lithium salt of a novel naphthalene bridged
bis(guanidinate) ligand and the corresponding lanthanide chlorides, as well as the metathesis reaction of
the chlorides with alkali metal salts of amines are also described.
5
10
15
Results and discussion
Synthesis and characterization of [Li2{LH2}2Li2] (LH2 = 1,8-C10H6{NC(NiPr)(NHiPr)}2) (1)
Our recent work shows that the bridged bis(guanidinate) with a soft linker was shown to be suitable
coordination platform, which allows the synthesis of isolable lanthanide monoborohydride and benzyl
complexes.9 Thus, a novel bridged bis(guanidinate) ligand precursor with a rigid naphthalene linker, LH4
(LH4 = 1,8ꢀC10H6{NC(NHiPr)2}2), was designed and the lithium salt [Li2{LH2}2Li2] (1) was synthesized
in 83% yield by the reaction of 1,8ꢀdiaminonaphthalene with 2 equiv of nBuLi, followed by treatment with
2 equiv of N,N′ꢀdiisopropylcarbodiimide in a THF solution (Scheme 1).
20
Complex 1 was fully characterized by NMR spectroscopy, elemental analysis as well as Xꢀray crystal
structure analysis.
3

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Scheme 1 Synthesis of 1.
The molecular structure of 1 with the selective bond lengths and angles is shown in Fig. 1. 1 is a
tetrametallic complex consisting of four Li atoms, two LH2 groups and one THF molecule. Each Li atom
is threeꢀcoordinate. The coordinated environment around the Li atoms can be divided into three types:
Li(1) is ligated by two nitrogen atoms (N(1) and N(2)) of one guanidinate group from one LH2 and one
nitrogen atom (N(7)) from the second LH2; Li(2) and Li(3) both are around by two nitrogen atoms attached
5
10
15
i
to the bridge from one LH2 and the third nitrogen atom at the Pr group of the second LH2, while Li(4) is
coordinated by two nitrogen atoms (N(10) and N(11)) of one guanidinate from one LH2 and one oxygen
atom from the THF molecule.
The three CꢀN bond lengths of each guanidine group (C(2)ꢀN(4) 1.381(5) Å, C(2)ꢀN(5) 1.310(5) Å
and C(2)ꢀN(6) 1.395(5) Å) indicate that the π electron of the C=N double bond is not delocalized within
the CN3 unit. The same bonding type is also found in the complexes with the severe steric bulky amidinate
or guanidinate ligands.10 The NꢀLiꢀN bond angles vary from 66.3° for the chelating guanidinates to 136.1°
for the bridging ones. The LiꢀN bond distances span a range from 1.919(9) to 2.234(9) Å. Thus the
structure is similar to those of other known Li guanidinates.11
Synthesis and characterization of [LnCl{LH2}] (Ln = Yb (2), Y (3))
Reaction of anhydrous LnCl3 with 0.5 equiv of 1 in THF at room temperature for 24 h afforded the
monochlorides [LnCl{LH2}] (Ln = Yb (2), Y (3)) in the yields of 70% for 2 and 66% for 3 (Scheme 2).
4

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Complexes 2 and 3 were obtained as air and moisture sensitive crystalline solids upon crystallization from
a mixture of THF/hexane. They are soluble in THF and toluene and poorly soluble in hexane.
1
Elemental analysis is consistent with their formulae. The H NMR spectra of the diamagnetic 3 in
C6D6 show the expected sets of signals assigned to the LH2 and the coordinated THF molecule.
5
Scheme 2 Synthesis of complexes 2 and 3.
Complexes 2 and 3 were further confirmed by Xꢀray singleꢀcrystal structure analysis. The molecular
structures of 2 and 3 are shown in Fig. 2 as they are isostructural. Selected bond lengths and angles are
listed in Table 1.
10
Both complexes crystallize in the monoclinic space group C2/c with the Yb(Y) atom, the Cl atom and
the two carbon atoms of the linker, C(6) and C(7), lying on a crystallographic two fold axis (thus, only half
the molecule is unique). Each metal atom is bound by two guanidinate groups in a η2ꢀfashion with one
chlorine atom and two THF molecules completing each coordination sphere. The center metal in each
complex is fiveꢀcoordinate, and adopts a pseudoꢀtrigonalꢀbipyramidal geometry, if the guanidinate groups
are considered to be point donors located at the central carbon atoms. The dihedral angle of the two LnꢀNꢀ
CꢀN planes here is 0.83° for 2 and 2.26° for 3, which is consistent with those found in the analogues
reported.12 The YbꢀCl (YꢀCl) distance (Table 1) is comparable with those in the related complexes [(e.g.,
fiveꢀcoordinate bridged bis(amidinate) Yb(Y) chloride,13 average 2.634 Å and fiveꢀcoordinate bridged
bis(guanidinate) Yb(Y) chloride,9a average 2.640 Å). The π electron of the C=N double bond is not
15
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delocalized within the CN3 unit as confirmed by the bond distances of C=N (Table 1). The bond distances
of metal to the guanidinate group are comparable with those reported for the related complexes.14
Reactions of 2 (or 3) with alkali metal amides: Sterically induced deprotonation to bridged (monoꢀ
and
dianionic)guanidinate
lanthanide
complexes,
[Ln{LH}]2
(LH
=
1,8-
5
C10H6{NC(NiPr)(NHiPr)}{NC(NiPr)2}; Ln = Yb (4), Y (5)), and the influence of amido group
Reactions of 2 and 3 with NaN(SiMe3)2 to 4 and 5
It is unexpected that the reaction between NaN(SiMe3)2 and 2 in THF at a molar ratio of 1:1 did not give
the amide complex [Yb{LH2}N(SiMe3)2], but the complex [Yb{LH}]2 (4) with bridged (monoꢀ and
dianionic)guanidinate ligand LH was obtained in good yield via the deprotonation of one of the
guanidinate group (Scheme 3). The formation of 4 was confirmed by elemental analysis and crystal
structure determination.
10
The same reaction of 3 with NaN(SiMe3)2 afforded the analogue 5 as the only product in 60% yield
1
(Scheme 3). Complex 5 was fully characterized by elemental analysis, H NMR and single crystal
structure determination.
15
Scheme 3 Reaction of [LnCl{LH2}] with NaN(SiMe3)2.
Complexes 4 and 5 are isostructural, their molecular structures are shown in Fig. 3. The selected bond
distances and angles are given in Table 2. Both complexes crystallize in the monoclinic space group C2/c
with a crystallographic inversion center located at the midpoint of Ln…Ln. Both have a cyclic structure
6

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consisting of two metals, two LH and two THF molecules. The ligand LH coordinates to two metals in a
ꢁꢀη1:η2:η2 fashion as a bridging ligand. Thus, the reꢀarrangement of the ligand, which leads to the
transformation of coordination mode from a chelating fashion to a bridging one, occurred during the
reaction process. This may be attributed to the requirement for stabilizing 4 and 5. Each center metal is
sixꢀcoordinate and bound to five nitrogen atoms of the one monoanionic guanidinate and two dianionic
guanidinate groups from the two LH and one oxygen atom from the THF molecule. The coordination
geometry can be described as a distorted trigonal pyramidal (assuming the guanidinate to occupy a single
coordination site at the central C atom of the NCN fragment).
5
10
15
The CꢀN bond distances of each dianionic guanidinate group (Table 2) are approximately equivalent,
indicating that the π electrons of the C=N double bond are delocalized over the CN3 unit.4dꢀ4g,15 Whilst, the
π electron of the C=N double bond in monoanionic guanidinate species is not delocalized within the CN3
unit.
The average bond distance of YbꢀN for the monoanionic guanidiante group (2.328(7) Å) is compared
to those of YbꢀN in the dianionic guanidinate groups (2.322(4) Å), this may be because both dianionic
guanidinate groups are bridging species and the bond distances of the Ybꢀbridged dianionic guanidinate
groups are normally longer than those of the Ybꢀunbridged one. The distance of Yb(Y)ꢀO bond is normal.
Influence of the size of amido group
Reactions of 2 with LiNH(C6H4Clꢀ4) and LiNH(C6H4CH3ꢀ4): Synthesis and characterization of
[Yb(NHC6H4Clꢀ4){LH2}]2 (6) and [Yb(NHC6H4CH3ꢀ4){LH2}]2 (7)
20
To understand the driving force for the occurrence of the deprotonation of LH2, the reactions of 2 with
metal salts of amide with various sizes were further investigated. The reaction of 2 with lithium salt of a
less bulky aromatic amide LiNH(C6H4Clꢀ4) was first conducted. Treatment of a solution of 2 in THF with
equivalent of LiNH(C6H4Clꢀ4) in THF gave a yellow solution. After workup, yellow crystals of 6 were
isolated in 58% yield (Scheme 4). Elemental analysis of the crystals is in good agreement with the
formula. The identity of 6 was unequivocally established by an Xꢀray structure determination.
25
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Replacing LiNH(C6H4Clꢀ4) by almost the same size lithium amide, LiNH(C6H4CH3ꢀ4), also led to
the formation of the analogous amide complex 7 as yellow crystals in 62% yield (Scheme 4). Complex 7
was confirmed by singleꢀcrystal structure analysis. Complexes 6 and 7 are extremely air and moisture
sensitive. They are soluble in THF and sparingly soluble in hexane.
iPr
iPr
NH
iPr
N
H
NHAr
N
N
N
N
iPr
iPr
iPr
THF
N
N
N
Yb
2 LiCl
N
N
HN
2
NH
+
2
LiNHAr
Yb
Yb
N
iPr
iPr
N
THF
N
iPr
Cl
iPr
ArHN
H
N
iPr
HN
iPr
Ar = 4ꢀClC6H4 (6), 4ꢀCH3C6H4 (7)
2
5
Scheme 4 Preparations of 6 and 7.
The molecular structures of 6 and 7 are depicted in Fig. 4 and 5, respectively. Selected bond distances
and angles are listed in Table 3. Complexes 6 and 7 both crystallize in the triclinic space group Pī with a
crystallographic inversion center located at the center of the Yb2N2 (Yb(1), Yb(1A), N(1) and N(1A)) core.
Both are binuclear cyclic complexes in which the two YbꢀN(amide) moieties are connected together by the
two LH2 groups. Both LH2 ligands adopt a ꢁꢀη1:η2:η2 coordination fashion. Obviously, the reꢀarrangement
of the ligand from a chelating to a bridging one occurred during the metathesis reaction. The reꢀ
arrangement of a bridged LH2 ligand here, similar to the case mentioned above, might be attributed to the
overcrowded coordination environment around the central metal in the original state.16 Each center metal
in both complexes is sixꢀcoordinate and bound to five nitrogen atoms of the three guanidinate fragments
from the two LH2 ligands and one amido group. The coordination geometry is a pseudoꢀtrigonal pyramidal
(assuming the guanidinate to occupy a single coordination site at the central C atom of the CN3 fragment).
The average bond distances of YbꢀN(guanidinate) fall in the ranges of lanthanide guanidinate
complexes.1,9 The π electron of the C=N double bond is not delocalized within the CN3 unit, which is as
10
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same as those in 2, 3 and the other related complexes.4c,10c The distance of YbꢀN(amide) (2.206(5) Å for 6
and 2.181(5) Å for 7) is comparable with those found in lanthanide amide complexes reported
previously.17
i
Reaction of 2 with LiNH(C6H3 Pr2ꢀ2,6): Formation of 4
i
5
However, the further reaction of 2 with the bulky sodium salt of amide NaNH(C6H3 Pr2ꢀ2,6) resulted in the
occurrence of deprotonation reaction of LH2, affording 4 as the only product in 56% yield, and no amide
i
complex [Yb(NHC6H3 Pr2ꢀ2,6){LH2}]2 could be obtained (Scheme 5). These results demonstrated that the
metathesis reaction of 2 with metal amide is very sensitive to the size of the amido group.
iPr
iPr
NH
NHAr
iPr
N
H
N
N
N
N
iPr
Yb
N
N
THF
iPr
Yb
N
N
N
iPr
iPr
2 NaCl
N
N
HN
i
N
Yb
2
+
2 NaNH(C6H3 Pr2ꢀ2,6)
i
H
N
H
Pr
N
ArHN
iPr
HN
iPr
iPr
THF
iPr
Cl
2
4 +
2 H2NAr
i
10
Scheme 5 Reaction of 2 with NaNH(C6H3 Pr2ꢀ2,6).
Possible mechanism for the formation of 4 and 5
Based on the above results, we may propose that the overcrowded coordination environment in lanthanide
amide formed, rather than the nucleophilic attack of MNHAr to LH2, leads to the further deprotonation of
LH2, although the detailed mechanism for the double deprotonation of LH4 has not been clear. Thus, the
pathway for the deprotonation via amineꢀelimination is proposed as shown in Scheme 6.
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Scheme 6 Possible pathway for the formation of 4 and 5.
The reaction of [LnCl{LH2}] with NaN(SiMe3)2 affords an unstable transient
[{Ln…N(SiMe3)2}{LH2}]2 with a loose ꢀN(SiMe3)2 farther from the Ln ion than their usual optimal
distance. The loose ꢀN(SiMe3)2 group in the transient is not electroꢀstatically stabilized as effectively as it
is in conventional amide complexes, such as 6 and 7. Thus, the unstable [{Ln…N(SiMe3)2}{LH2}]2
transfers to the stable complex 4 (or 5) via elimination of HN(SiMe3)2.
5
Reactivity of 4 toward NH2Ar (Ar = C6H4Clꢀ4 and C6H4CH3ꢀ4): A facile route for the preparation
of 6 and 7
10
The reactivity of bianionic guanidinate Ti complex [Ti{(Me2N)C(NiPr)2}2{iPrNC(NC6F5)(NiPr)}] toward
amine was reported to yield an imido complex with the formation of guanidine.8 Thus, the reactivity of 4
towards NH2Ar was investigated.
Treatment of 4 with 2 equiv of NH2(C6H4Clꢀ4) in THF at room temperature led to the color change of
the solution from red to yellow immediately. Removing the volatiles, washing with hexane, and extracting
with toluene gave yellow crystals in 51% yield upon crystallization. The crystals were confirmed by
determination of the unit cell of the single crystals to be 6. Also the same reaction with NH2(C6H4CH3ꢀ4)
afforded the yellow crystals, which were characterized to be 7 as shown in Scheme 7. The reaction was not
effected by either electronꢀwithdrawing substituent (ꢀCl) or electronꢀdonating substituent (ꢀCH3) at the
phenyl ring of aromatic amines. However, the reaction is sensitive to the size of the amine.
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iPr
NH iPr
iPr
N
H
NHAr
N
N
N
iPr
iPr
Yb
NH
N
N
2 H2NAr
THF
N
iPr
iPr
N
Yb
N
iPr
N
ArHN
N
N
THF
Yb
iPr
H
N
iPr
N
N
iPr
HN iPr
iPr
N
N
THF
Yb
Ar = 4ꢀClC6H4 (6), 4ꢀCH3C6H4 (7)
N
iPr
N
N
iPr
i
NH C H Pr ꢀ2,6
2
2
6
3
2
iPr
no reaction
HN
THF
4
Scheme 7 Reactivity of 4 toward aromatic amines.
i
When 4 was treated with bulkier amine, NH2(C6H3 Pr2ꢀ2,6), no reaction was observed (Scheme 7).
i
The failure in the formation of [Yb(NHC6H3 Pr2ꢀ2,6){LH2}]2, which is in accordance with the result
i
5
obtained from the metathesis of 2 with LiNH(C6H3 Pr2ꢀ2,6) (see above paragraph), is not surprised and
i
might be attributed to the instability of the overcrowded [Yb(NHC6H3 Pr2ꢀ2,6){LH2}]2 formed in situ.
Reaction of 4 with [HNEt3][BPh4] was tried in an attempt to synthesize a corresponding cationic
guanidinate complex. However, the reaction did not occur and the starting materials were recovered.
Conclusion
10
The new tetranuclear lithium salt of bridged bis(guanidinate) with a rigid naphthalene linker
[Li2{LH2}2Li2] and the lanthanide chlorides [LnCl{LH2}] were prepared. The deprotonation of the LH2 in
a highly encumbered lanthanide amide complex has been explored. To our best knowledge, this is the first
example of sterically induced deprotonation of a coordinated bridged bis(guanidinate) ligand in lanthanide
complexes. Thus, the size of the amido group is found to have a great influence on the outcome of the
metathesis reaction between [LnCl{LH2}] and alkali metal amides: corresponding amide complexes 6 and
7 could be prepared using less bulky metal amides, whereas the deprotonation products 4 and 5 were
isolated by use of bulky metal amides. Reaction of 4 with appropriate aromatic amines afforded lanthanide
amide complexes, which represents an alternative route for the synthesis of lanthanide amides. The high
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reactivity of [Yb{LH}]2 is likely to find more general applications in synthesis of metal complex. The
related work is ongoing.
Experimental
General procedures
5
10
15
20
All manipulations and reactions described below were carried out under a purified argon atmosphere using
standard Schlenk or glovebox techniques. Solvents were degassed and distilled from sodium
benzophenone ketyl under argon before use. N,N′ꢀdiisopropylcarbodiimide was purchased from Alfa Aesar
and dried over CaH2 for 48 h and distilled under reduced pressure. The other reagents were purchased
from Acros Chemical and used as received without further purification. The 1H and 13C NMR spectra were
recorded in a C6D6 solution for complexes 1, 3 and 5 with a Unity Varian spectrometer. Because of their
paramagnetism, no resolvable NMR spectrum for the other complexes was obtained. Elemental analysis
was performed by direct combustion using a CarloꢀErba EA 1110 instrument. The IR spectra were
recorded on a MagnaꢀIR 550 spectrometer as KBr pellets.
[Li4{LH2}2(THF)] (1). To a solution of 1,8ꢀDiaminonaphthalene (1.45 g, 9.16 mmol) in THF (30
o
mL) was slowly added a solution of nBuLi in hexane (6.59 mL 2.78 M, 18.32 mmol) at 0 C. The reaction
mixture was stirred for 6 h. N,N′ꢀdiisopropylcarbodiimide (2.86 mL, 18.32 mmol) was then added
dropwise to the solution. The mixture was stirred for 24 h, after which the solvent was removed to dry
o
under vacuum conditions. The product was extracted with a mixture of THF/hexane. Cooling to 0 C
yielded colorless crystals of 1 (3.49 g, 83%). Anal. Calcd for C52H80N12OLi4 (917.04): C, 68.10; H, 8.72;
N, 18.32%. Found: C, 67.99; H, 8.69; N, 18.41%. 1H NMR (400 MHz, C6D6): δ 7.37ꢀ6.38 (m, 12H, Arꢀ
H), 4.15ꢀ2.83 (m, 16H, NH, αꢀCH2 THF and CH(CH3)2), 1.43ꢀ1.30 (m, 4H, βꢀCH2 THF), 1.28ꢀ0.40 (m,
48H, CH3). 13C NMR (75 MHz, C6D6): 163.8 (C=N), 162.4 (C=N), 162.3 (C=N), 161.9 (C=N), 156.5
(Ar), 153.6 (Ar), 151.5 (Ar), 149.1 (Ar), 140.7 (Ar), 139.3 (Ar), 138.9 (Ar), 126.7 (Ar), 126.4 (Ar), 125.7
(Ar), 125.0 (Ar), 124.6 (Ar), 121.6 (Ar), 119.1 (Ar), 117.4 (Ar), 115.8 (Ar), 114.9 (Ar), 113.8 (Ar), 113.1
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(Ar), 107.9 (Ar), 67.7 (αꢀCH2 THF) ， 46.9 (CH(CH3)2), 46.2 (CH(CH3)2), 45.9 (CH(CH3)2), 45.8
(CH(CH3)2), 45.2 (CH(CH3)2), 44.5 (CH(CH3)2), 43.9 (CH(CH3)2), 43.5 (CH(CH3)2), 27.0 (CH3), 26.1
(CH3), 25.8 (CH3), 25.7 (CH3), 25.6 (CH3), 25.3 (βꢀCH2 THF), 24.8 (CH3), 24.6 (CH3), 24.5 (CH3), 24.1
(CH3), 23.7 (CH3), 23.5 (CH3), 23.2 (CH3). IR (KBr, cmꢀ1): 3270 (m), 2963 (s), 1630 (s), 1573 (s), 1493
(s), 1465 (s), 1384 (m), 1230 (s), 1157 (s), 863 (m), 763 (w), 624 (w), 505 (m).
5
10
15
20
25
[YbCl{LH2}(THF)2] (2). A white suspension of YbCl3 (2.45 g, 8.78 mmol) in THF (20 mL) was
added to a solution of 1 (4.02 g, 4.39 mmol) in THF (20 mL). The mixture was stirred for 24 h at room
temperature, and then the solvent was removed to dry under vacuum conditions. The residue was extracted
with toluene and the LiCl was removed by centrifugation. The extracts were concentrated and cooled to 0
oC. Complex 2 was obtained as yellow crystals in a few days (4.68 g, 70%). Anal. Calcd for
C32H52ClN6O2Yb (761.29): C, 50.48; H, 6.83; N, 11.03%. Found: C, 50.11; H, 6.67; N, 10.90%. IR (KBr,
cmꢀ1): 3270 (w), 2972 (m), 2870 (w), 1614 (s), 1576 (s), 1384 (m), 1241 (m), 1158 (s), 864 (w), 765 (m),
504 (m).
[YCl{LH2}(THF)2] (3). The synthesis of complex 3 was carried out in the same way as that
o
described for complex 2. Pale yellow crystals were obtained at 0 C (3.92 g, 66%). Anal. Calcd for
1
C32H52ClN6O2Y (677.16): C, 56.75; H, 7.68; N, 12.40%. Found: C 56.31; H, 7.47; N, 12.64%. H NMR
(400 MHz, C6D6): δ 7.50ꢀ6.35 (m, 6H, ArꢀH), 4.10ꢀ3.15 (br, 14H, NH, αꢀCH2 THF and CH(CH3)2), 1.81ꢀ
13
0.40 (m, 32H, βꢀCH2 THF and CH3). C NMR (101 MHz, C6D6): 164.4 (C=N), 146.3 (Ar), 138.5 (Ar),
125.9 (Ar), 125.3 (Ar), 117.4 (Ar), 111.2 (Ar), 69.7 (αꢀCH2 THF), 46.9 (CH(CH3)2), 45.56 (CH(CH3)2),
25.7 (CH3), 25.1 (βꢀCH2 THF), 24.8 (CH3), 24.6 (CH3), 24.0 (CH3). IR (KBr, cmꢀ1): 3273 (w), 2970 (m),
2858 (m), 1615 (s), 1588 (s), 1381 (m), 1235 (m), 1158 (s), 873 (m), 826 (w), 764 (w), 505 (m).
[Yb{LH}(THF)]2 (4). Method 1. A solution of NaN(SiMe3)2 in toluene (10.0 mL, 3.00 mmol) was
added to a solution of 2 (2.28 g, 3.00 mmol) in THF (20 mL) slowly under stirring at room temperature.
The mixture was stirred for 24 h, and then the solvent was removed to dry under vacuum conditions. The
residue was extracted with toluene and the undissolved portion was removed by centrifugation. The
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resulting red solution was concentrated at room temperature to give 4 (1.14 g, 58%) as orange crystals.
Anal. Calcd for C56H86N12O2Yb2 (1305.44): C, 51.52; H, 6.64; N, 12.88%. Found: C, 51.16; H, 6.37; N,
12.59%. IR (KBr, cm−1): 3232(m), 2969 (m), 2873(w), 2186 (m), 1627 (m), 1573 (m), 1463 (w), 1384
(w), 1207 (s), 1153 (s), 821 (m), 763 (m), 636 (m) 505 (m).
5
10
15
20
25
Method 2. The synthesis of complex 4 was carried out in the same way as that described in method 1,
i
but corresponding NaNH(C6H3 Pr2ꢀ2,6) (10.0 ml in toluene, 3.00 mmol) and 2 (2.28 g, 3.00 mmol) were
used. The orange crystals of complex 4 were isolated (yield 1.10 g, 56%).
[Y{LH}(THF)]2 (5). The synthesis of complex 5 was carried out as that described for complex 4 in
the method 1. Light yellow crystals of complex 5 were isolated (1.02 g, 60%). Anal. Calcd for
1
C56H86N12O2Y2 (1137.17): C, 59.15; H, 7.62; N, 14.78%. Found: C, 58.90; H, 7.47; N, 14.54%. H NMR
(400 MHz, C6D6): δ 7.40ꢀ6.70 (m, 12H, ArꢀH), 4.45ꢀ3.31 (m, 18H, NH, αꢀCH2 THF and CH(CH3)2), 1.85ꢀ
0.75 (m, 56H, βꢀCH2 THF and CH3). 13C NMR (101 MHz, C6D6): 162.1 (CN3), 159.2 (C=N), 150.6 (Ar),
149.7 (Ar), 140.5 (Ar), 125.7 (Ar), 124.7 (Ar), 122.3 (Ar), 114.9 (Ar), 114.2 (Ar), 109.7 (Ar), 109.2 (Ar),
69.1 (αꢀCH2 THF), 46.4 (CH(CH3)2), 45.9 (CH(CH3)2), 45.0 (CH(CH3)2), 44.5 (CH(CH3)2), 26.3 (CH3),
26.0 (CH3), 25.7 (CH3), 25.6 (CH3), 24.9 (βꢀCH2 THF), 24.7 (CH3), 24.5 (CH3), 24.0 (CH3), 23.1 (CH3).
IR (KBr, cm−1): 3230(m), 2972(m), 2881(w), 2184 (m), 1627 (m), 1573 (m), 1462 (w), 1381 (w), 1201 (s),
1156 (s), 820 (m), 773 (s), 632 (m), 503 (m).
[Yb(NHC6H4Cl-4){LH2}]2 (6). Method 1. The synthesis of complex 6 was carried out as that
described for complex 4 in the method 1, but corresponding LiNH(C6H4Clꢀ4) (0.40 g, 3.00 mmol) and 2
(2.28 g, 3.00 mmol) were used. The yellow crystals of complex 6 were isolated (yield 1.23 g, 58%). Anal.
Calcd for C60H82Cl2N14Yb2 (1416.37): C, 50.88; H, 5.84; N, 13.84%. Found: C, 51.04; H, 5.54; N,
13.70%. IR (KBr, cm−1): 3350 (s), 3297 (w), 2969 (m), 1631 (s), 1569 (s), 1500 (m), 1465 (m), 1384 (m),
1234 (s), 1157 (s), 825 (w), 700 (s), 643 (m), 555 (m).
Method 2. A solution of NH2(C6H4Clꢀ4) (0.42 g, 3.32 mmol) in THF (10 mL) was added into a
solution of the complex 4 (2.17 g, 1.66 mmol) in THF (20 mL) slowly under stirring. The mixture was
14

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stirred at room temperature for 24 h. Volatiles were removed under vacuum, and the solid residue was
crystallized from toluene at 0 °C to give 1.19 g (51%) of yellow crystals.
[Yb(NHC6H4CH3-4){LH2}]2 (7). Method 1. The synthesis of complex 7 was carried out as that
described for complex 4 in the method 1, but corresponding LiNH(C6H4CH3ꢀ4) (0.34 g, 3.00 mmol) and 2
(2.28 g, 3.00 mmol) were used. The yellow crystals of complex 7 were isolated (yield 1.28 g, 62%). Anal.
Calcd for C62H88N14Yb2 (1375.54): C, 54.14; H, 6.45; N, 14.26%. Found: C, 54.46; H, 6.79; N, 14.50%.
IR (KBr, cm−1): 3348 (s), 3290 (w), 2953 (m), 1630 (s), 1572 (m), 1500 (m), 1464 (m), 1384 (m), 1340
(m), 1246 (s), 1157 (s), 820 (m), 763 (w), 625 (m), 555 (m).
5
Method 2. The synthesis of complex 7 was carried out as that described for complex 6 in the method
2, but corresponding NH2(C6H4CH3ꢀ4) (0.38 g, 3.54 mmol) and 4 (2.31 g, 1.77 mmol) were used. The
yellow crystals of complex 7 were isolated (yield 1.28 g, 53%).
10
X-Ray crystallographic structure determinations
Crystals of complexes 1ꢀ7 suitable for Xꢀray diffraction were sealed in a thinꢀwalled glass capillary filled
under argon. Diffraction data were collected on a Agilent Xcalibur CCD area detector in the ω scan mode
using Mo Kα radiation (λ = 0.71070 Å) for complexes 2, 5 and 7 and on a Rigaku Saturn CCD area
detector in the ω scan mode using Mo Kα radiation (λ = 0.71075 Å) for complexes 1, 3, 4, and 6. The
diffracted intensities were corrected for Lorentzꢀpolarization effects and empirical absorption corrections.
Details of the intensity data collection and crystal data are given in Table 4. The structures were solved by
direct methods and refined by fullꢀmatrix leastꢀsquares procedures based on |F|2. All of the nonꢀhydrogen
atoms were refined with anisotropic displacement coefficients. The hydrogen atoms in these complexes
were all generated geometrically, assigned appropriate isotropic thermal parameters, and allowed to ride
on their parent carbon atoms. All of the hydrogen atoms were held stationary and included in the structure
factor calculations in the final stage of fullꢀmatrix leastꢀsquares refinement. The structures were solved
and refined using SHELXLꢀ97 programs.
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Acknowledgements
We are grateful to the National Natural Science Foundation of China (Grants No. 21132002, 20972107), a
project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
for financial support.
5
Notes and references
a Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering
and Materials Science, Soochow University, Suzhou 215123, People’s Republic of China. Fax: 86 512
65880305; Tel: 86 512 65882806; Eꢀmail: qshen@suda.edu.cn; xuemingqiang@suda.edu.cn
† Electronic Supplementary Information (ESI) available: CCDC 909529 (for 1), 909530 (for 2), 909531
(for 3), 909532 (for 4), 909533 (for 5), 909534 (for 6), 909535 (for 7).
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1 (a) Y. Zhou, G. P. A. Yap, D. S. Richeson, Organometallics, 1998, 17, 4387. (b) P. J. Bailey, S. Pace,
Coord. Chem. Rev., 2001, 214, 91. (c) F. T. Edelmann, Adv. Organomet. Chem., 2008, 57, 183. (d) F.
T. Edelmann, Chem. Soc. Rev., 2009, 38, 2253. (e) C. Jones, Coord. Chem. Rev., 2010, 254, 1273. (f)
F. T. Edelmann, Chem. Soc. Rev., 2012, 41, 7657. (g) A. A. Trifonov, Coord. Chem. Rev., 2010, 254,
1327.
2 (a) N. J. Bremer, A. B. Cutcliff, M. F. Farona, W. G. Kofron, J. Chem. Soc., A, 1971, 3264. (b) K. R.
Birdwhistell, J. Lanza, J. Pasos, J. Organomet. Chem., 1999, 584, 200. (c) R. L. Zuckerman, R. G.
Bergman, Organometallics, 2000, 19, 4795. (d) R. L. Zuckerman, R. G. Bergman, Organometallics,
2001, 20, 1792. (e) T. G. Ong, G. P. A. Yap, D. S. Richeson, Chem. Commun., 2003, 2612.
3 M. B. Dinger, W. Henderson, Chem. Commun., 1996, 211.
4 (a) P. J. Bailey, A. J. Blake, M. Kryszczuk, S. Parsons, D. Reed, J. Chem. Soc., Chem. Comm., 1995,
1647. (b) T. Chivers, M. Parvez, G. Schatte, J. Organomet. Chem., 1998, 550, 213. (c) S. R. Foley, G.
P. A. Yap, D. S. Richeson, Inorg. Chem., 2002, 41, 4149. (d) P. Zheng, J. Hong, R. Liu, Z. Zhang, Z.
16

Page 17 of 28
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Pang, L. Weng, X. Zhou, Organometallics, 2010, 29, 1284. (e) C. Qian, X. Zhang, J. Li, F. Xu, Q.
Shen, J. Organomet. Chem., 2010, 695, 747. (f) C. Qian, X. Zhang, J. Li, F. Xu, Y. Zhang, Q. Shen,
Organometallics, 2009, 28, 3856. (g) X. Zhang, C. Qian, C. Wang, Y. Zhang, Y. Wang, Y. Yao, Q.
Shen, Eur. J. Inorg. Chem., 2012, 847.
5
10
15
20
25
5 C. Pi, Z. Zhang, Z. Pang, J. Zhang, J. Luo, Z. Chen, L. Weng, X. Zhou, Organometallics, 2007, 26,
1934.
6 (a) M. K. T. Tin, N. Thirupathi, G. P. A. Yap, D. S. Richeson, J. Chem. Soc., Dalton Trans., 1999,
2947. (b) P. J. Bailey, R. O. Gould, C. N. Harmer, S. Pace, A. Steiner, D. S. Wright, Chem. Commun.,
1997, 1161.
7 N. Thirupathi, G. P. A. Yap, D. S. Richeson, Organometallics, 2000, 19, 2573.
8 T. G. Ong, G. P. A. Yap, D. S. Richeson, J. Am. Chem. Soc., 2003, 125, 8100.
9 (a) X. Zhang, C. Wang, M. Xue, Y. Zhang, Y. Yao, Q. Shen, J. Organomet. Chem., 2012, 716, 86. (b)
X. Zhang, C. Wang, M. Xue, Y. Zhang, Y. Yao, Q. Shen, J. Organomet. Chem., 2012, 713, 182.
10 (a) J. A. R. Schmidt, J. Arnold, J. Chem. Soc., Dalton Trans., 2002, 2890. (b) M. Zhou, H. B. Tong, X.
H. Wei, D. S. Liu, J. Organomet. Chem., 2007, 692, 5195. (c) S. P. Green, C. Jones, G. Jin, A. Stasch,
Inorg. Chem., 2007, 46, 8.
11 (a) M. Zhou, X. Qiao, H. Tong, T. Gong, M. Fan, Q. Yang, Q. Dong, J. Chao, Z. Guo, D. Liu, Inorg.
Chem., 2012, 51, 4925. (b) A. M. Willcocks, T. P. Robinson, C. Roche, T. Pugh, S. P. Richards, A. J.
Kingsley, J. P. Lowe, A. L. Johnson, Inorg. Chem., 2012, 51, 246.
12 (a) D. Heitmann, C. Jones, P. C. Junk, K.ꢀA. Lippert, A. Stasch, Dalton Trans., 2007, 187. (b) D.
Heitmann, C. Jones, D. P. Millsa, A. Stasch, Dalton Trans., 2010, 1877. (c) M. V. Yakovenko, A. V.
Cherkasov, G. K. Fukin, D. Cui, A. A. Trifonov, Eur. J. Inorg. Chem., 2010, 3290.
13 (a) A. O. Tolpygin, A. S. Shavyrin, A. V. Cherkasov, G. K. Fukin, A. A. Trifonov, Organometallics,
2012, 31, 5405. (b) S. Bambirra, A. Meetsma, B. Hessen, J. H. Teuben, Organometallics, 2001, 20,
782. (c) J. Wang, Y. Yao, J. L. Cheng, X. Pang, Y. Zhang, Q. Shen, J. Mol. Struct., 2005, 743, 229.
17

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14 (a) D. M. Lyubov, G. K. Fukin, A. A. Trifonov, Inorg. Chem., 2007, 46, 11450. (b) A. A. Trifonov, D.
M. Lyubov, E. A. Fedorova, G. K. Fukin, H. Schumann, S. Mühle, M. Hummert, M. N. Bochkarev,
Eur. J. Inorg. Chem., 2006, 4, 747. (c) Y. Yao, Y. Luo, J. Chen, Z. Zhang, Y. Zhang, Q. Shen, J.
Organomet. Chem., 2003, 679, 229. (d) Y. Luo, Y. Yao, Q. Shen, K. Yu, Eur. J. Inorg. Chem., 2002,
2, 318.
5
10
15
20
25
15 (a) C. Pi, Z. Zhu, L. Weng, Z. Chen, X. Zhou, Chem. Commun., 2007, 2190. (b) C. Pi, R. Liu, P.
Zheng, Z. Chen, X. Zhou, Inorg. Chem., 2007, 46, 5252.
16 (a) G. Desurmont, Y. Li, H. Yasuda, T. Maruo, N. Kanehisa, Y. Kai, Organometalics, 2000, 19, 1811.
(b) D. Stern, M. Sabatand, T. J. Marks, J. Am. Chem. Soc., 1990, 112, 9558. (c) J. Wang, Y. Yao, Y.
Zhang, Q. Shen, Inorg. Chem., 2009, 48, 744.
17 (a) M. R. Douglass, M. Ogasawara, S. Hong, M. V. Metz, T. J. Marks, Organometallics, 2002, 21,
283. (b) Y. Wu, S. Wang, X. Zhu, G. Yang, Y. Wei, L. Zhang, H. Song, Inorg. Chem., 2008, 47, 5503.
(c) J. Wang, T. Cai, Y. Yao, Y. Zhang, Q. Shen, Dalton Trans., 2007, 5275. (d) W. Li, M. Xue, F. Xu,
J. Tu, Y. Zhang, Q. Shen, Dalton Trans., 2012, 8252.
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Table 1 Selected bond lengths (Å) and angles (o) for complexes 2 and 3
2
3
2
3
Bond Lengths
Ln(1)ꢀN(1)
Bond Angles
2.284(3)
2.412(4)
2.780(4)
2.6120(14)
2.337(3)
1.349(5)
1.313(5)
1.383(5)
2.312(5)
2.432(4)
2.798(6)
2.663(3)
2.364(4)
1.361(7)
1.305(7)
1.386(7)
N(1)ꢀLn(1)ꢀN(2)
56.35(10)
91.29(6)
56.05(15)
91.61(10)
115.8(7)
128.3(3)
176.8(2)
113.7(5)
123.7(5)
122.6(6)
Ln(1)ꢀN(2)
Ln(1)ꢀC(1)
Ln(1)ꢀCl(1)
Ln(1)ꢀO(1)
N(1)ꢀC(1)
N(2)ꢀC(1)
N(3)ꢀC(1)
O(1)ꢀLn(1)ꢀCl(1)
C(1)ꢀLn(1)ꢀCl(1)
C(1)ꢀLn(1)ꢀC(1A)
O(1)ꢀLnꢀO(1A)
N(1)ꢀC(1)ꢀN(2)
N(2)ꢀC(1)ꢀN(3)
N(3)ꢀC(1)ꢀN(1)
115.13(8)
129.75(17)
177.41(12)
113.1(3)
124.2(4)
122.7(4)
5
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Table 2 Selected bond lengths (Å) and angles (o) for complexes 4 and 5
4
5
4
5
Bond Lengths
Ln(1)ꢀN(1)
Ln(1)ꢀN(4)
Ln(1)ꢀN(5)
Ln(1)ꢀN(2A)
Ln(1)ꢀN(3A)
Ln(1)ꢀO(1)
N(1)ꢀC(1)
Bond Angles
2.293(8)
2.281(8)
2.375(7)
2.241(8)
2.431(6)
2.341(7)
1.351(11)
1.376(11)
1.351(11)
1.385(12)
1.322(11)
1.384(12)
2.329(3)
2.326(3)
2.428(3)
2.291(3)
2.471(3)
2.393(3)
1.380(4)
1.379(4)
1.329(4)
1.366(4)
1.321(4)
1.372(5)
N(4)ꢀLn(1)ꢀN(5)
N(2A)ꢀLn(1)ꢀN(3A)
Ln(1A)ꢀN(2)ꢀLn(1)
N(1)ꢀLn(1)ꢀO(1)
O(1)ꢀLn(1)ꢀC(1A)
O(1)ꢀLn(1)ꢀC(2)
N(1)ꢀC(1)ꢀN(3)
N(1)ꢀC(1)ꢀN(2)
N(3)ꢀC(1)ꢀN(2)
N(5)ꢀC(2)ꢀN(6)
N(5)ꢀC(2)ꢀN(4)
N(6)ꢀC(2)ꢀN(4)
57.9(3)
56.09(9)
56.69(9)
107.11(10)
98.19(10)
122.74(10)
91.38(10)
130.3(3)
114.3(3)
113.6(3)
123.5(3)
112.7(3)
123.7(3)
57.7(3)
107.9(3)
99.2(3)
121.7(3)
91.9(3)
130.5(8)
116.2(8)
111.9(7)
123.8(8)
112.9(8)
123.2(8)
N(2)ꢀC(1)
N(3)ꢀC(1)
N(4)ꢀC(2)
N(5)ꢀC(2)
N(6)ꢀC(2)
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Table 3 Selected bond lengths (Å) and angles (o) for complexes 6 and 7
6
7
6
7
Bond Lengths
Yb(1)ꢀN(1A)
Yb(1)ꢀN(2A)
Yb(1)ꢀN(4)
Yb(1)ꢀN(5)
Yb(1)ꢀN(1)
Yb(1)ꢀN(7)
N(1)ꢀC(1)
Bond Angles
2.536(5)
2.329(5)
2.238(5)
2.238(5)
2.361(5)
2.206(5)
1.403(8)
1.299(8)
1.344(8)
1.365(8)
1.317(8)
1.370(8)
2.560(4)
2.333(4)
2.239(4)
2.357(4)
2.350(5)
2.181(5)
1.386(7)
1.319(7)
1.362(7)
1.375(7)
1.317(7)
1.374(7)
N(7)ꢀYb(1)ꢀN(4)
N(4)ꢀYb(1)ꢀN(5)
N(2A)ꢀYb(1)ꢀN(1A)
N(1)ꢀYb(1)ꢀN(1A)
Yb(1)ꢀN(1)ꢀYb(1A)
N(2)ꢀC(1)ꢀN(3)
N(2)ꢀC(1)ꢀN(1)
N(3)ꢀC(1)ꢀN(1)
N(5)ꢀC(2)ꢀN(4)
N(5)ꢀC(2)ꢀN(6)
N(4)ꢀC(2)ꢀN(6)
116.8(2)
58.53(18)
55.81(17)
85.70(17)
94.30(17)
125.4(6)
115.3(5)
119.2(6)
113.6(6)
123.7(6)
122.6(6)
117.07(18)
58.26(17)
55.48(15)
86.40(14)
114.3(3)
124.9(5)
115.3(4)
119.7(5)
112.6(5)
124.3(5)
122.9(5)
N(2)ꢀC(1)
N(3)ꢀC(1)
N(4)ꢀC(2)
N(5)ꢀC(2)
N(6)ꢀC(2)
5
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Table 4 Crystallographic Data for Complexes 1ꢀ7
1
2
3
4·5(THF)
5·5(THF)
6·3(toluene)
7ꢂ(THF)
C76H126N12O7 C76H126N12O7 C81H106Cl2N14 C66H96N14O
Formula
C52H80N12OLi4 C32H52ClN6O2Yb C32H52ClN6O2Y
Yb2
Y2
Yb2
Yb2
fw
917.04
223(2)
0.71075
Triclinic
Pī
761.29
677.16
1665.97
223(2)
1497.71
220(2)
1692.78
223(2)
0.71075
Triclinic
Pī
1447.65
220(2)
0.71070
Triclinic
Pī
T/K
223(2)
223(2)
λ/Å
0.71070
Monoclinic
C2/c
0.71075
Monoclinic
C2/c
0.71075
Monoclinic
C2/c
0.71070
Monoclinic
C2/c
Crystal system
Space group
0.70 × 0.30 ×
0.30
0.60 × 0.40 × 0.60 × 0.50 × 0.80 × 0.50 ×
0.40 × 0.18 ×
0.15
Crystal size/mm
0.60 × 0.40 × 0.30 0.70 × 0.60 × 0.40
0.35
0.30
0.40
a/Å
b/Å
c/Å
α /°
β/°
11.100(2)
12.745(3)
21.549(6)
86.141(18)
85.522(18)
64.633(12)
2744.4(11)
2
13.8453(6)
12.2986(4)
20.3408(9)
90
13.835(5)
12.374(5)
20.243(8)
90
27.103(7)
18.045(5)
16.717(5)
90
27.2799(11)
18.1316(7)
16.7684(7)
90
11.4364(18)
12.8922(15)
15.651(3)
72.96(2)
84.03(3)
64.624(19)
1992.8(6)
1
11.5151(6)
12.9495(8)
13.0112(7)
98.036(5)
92.863(4)
116.207(6)
1709.95(17)
1
93.541(4)
90
93.448(10)
90
105.444(7)
90
105.244(4)
90
γ/°
V/Å3
Z/Å3
3457.0(2)
4
3459(2)
4
7881(4)
4
8002.3(6)
4
D
calcd/g cmꢀ3
/mmꢀ1
1.110
1.463
2.819
1556
1.300
1.799
1432
1.404
2.417
864
1.243
1.5
1.411
2.45
1.406
2.768
0.067
µ
F(000)
992
748
3448
738
3.21ꢀ25.50
23279
10188
2.95ꢀ25.49
6650
3.05ꢀ25.49
8940
3.02ꢀ25.50
32764
7308
3.19ꢀ25.50
18163
7422
3.05ꢀ25.50
16645
7370
3.19ꢀ25.50
16040
6363
θrange/°
Total no. of rflns
No. of indep rflns
3148
3201
Rint
0.074
0.0365
0.0787
0.0827
0.035
0.0511
0.052
GOF
1.076
1.031
0.964
1.188
1.04
1.101
1.039
R [I >2σ(I)]
wR
0.0995
0.2415
0.0330
0.0756
0.0748
0.1845
0.0718
0.1459
0.0492
0.1279
0.0508
0.1162
0.0434
0.1046
Largest diff. peak and
hole/e Åꢀ3
0.815, ꢀ0.519
1.302, ꢀ0.573
0.886, ꢀ1.569
0.919, ꢀ1.152 0.659, ꢀ0.665 1.091, ꢀ1.528
1.635, ꢀ1.485
5
22

Page 23 of 28
Dalton Transactions
View Article Online
5
Fig. 1 Molecular structure of complex 1. Thermal ellipsoids are drawn at the 30% probability level.
Hydrogen atoms (except those on the nitrogen atoms) are omitted for clarity. Selected bond distances (Å)
and angles (°): Li(1)ꢀN(1) 2.147(8), Li(1)ꢀN(2) 1.970(9), Li(1)ꢀN(7) 2.138(9), Li(2)ꢀN(1) 1.942(8), Li(2)ꢀ
N (4) 1.919(9), Li(2)ꢀN(8) 1.982(8), Li(3)–N(5) 2.003(7), Li(3)ꢀN(7) 1.964(8), Li(3)ꢀN(10) 1.933(7),
Li(4)ꢀN(10) 2.234(9), Li(4)ꢀN(11) 1.960(9), Li(4)ꢀO(1) 1.888(9), N(1)ꢀC(1) 1.400(5), N(2)ꢀC (1) 1.306(5),
N(3)ꢀC(1) 1.374(5), N(4)ꢀC(2) 1.381(5), N(5)ꢀC(2) 1.310(5), N(6)ꢀC(2) 1.395(5), N(7)ꢀC(25) 1.382(5),
N(8)ꢀC(25) 1.310(5), N(9)ꢀC(25) 1.380(5), N(10)ꢀC(26) 1.403(5), N(11)ꢀC(26) 1.294(5), N(12)ꢀC(26)
1.382(5), N(2)ꢀLi(1)ꢀN(1) 68.3(3), N(4)ꢀLi(2)ꢀN(8) 136.1(4), N(7)ꢀLi(3)ꢀN(5) 134.8(4), N(11)ꢀLi(4)ꢀN(10)
66.3(3).
10
15
23

Dalton Transactions
Page 24 of 28
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5
Fig. 2 Molecular structures of complexes 2 and 3. Thermal ellipsoids are drawn at the 30% probability
level. Hydrogen atoms (except those on the nitrogen atoms) are omitted for clarity.
10
15
24

Page 25 of 28
Dalton Transactions
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5
Fig. 3 Molecular structures of complexes 4 and 5. Thermal ellipsoids are drawn at the 30% probability
level. Hydrogen atoms (except those on the nitrogen atoms) and free THF molecules in the lattice are
omitted for clarity.
10
15
25

Dalton Transactions
Page 26 of 28
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5
Fig. 4 Molecular structure of complex 6. Thermal ellipsoids are drawn at the 30% probability level.
Hydrogen atoms (except those on the nitrogen atoms) and free toluene molecules in the lattice are omitted
for clarity.
10
15
26

Page 27 of 28
Dalton Transactions
View Article Online
5
Fig. 5 Molecular structure of complex 7. Thermal ellipsoids are drawn at the 30% probability level.
Hydrogen atoms (except those on the nitrogen atoms) and free THF molecule in the lattice are omitted for
clarity.
10
15
27

Dalton Transactions
Page 28 of 28
View Article Online
Unprecedented reaction of bridged bis(guanidinate)
lanthanide complexes: Sterically induced
deprotonation
Chuanyong Wang, Xingmin Zhang, Mingqiang Xue,* Yong Zhang and Qi Shen*
Text:
Synthesis of bridged (mono- and dianionic)guanidinate lanthanide complexes by
sterically induced deprotonation and their reactivity toward amines are described.
Graphic: