Heterometallic octanuclear REIII3NiII 5 (RE = DyIII, GdIII and YIII) clusters with slow magnetic relaxation for the dysprosium derivative

Article abstract of DOI:10.1039/c3dt32572e

Reactions of rare earth benzoate and nickel perchlorate with a Schiff-base ligand, 2-([(2-hydroxyphenyl)imino]methyl) phenol (H₂L), in the presence of triethylamine yielded three heterobimetallic octanuclear clusters of general formula [RE₃Ni₅L₅(PhCOO) ₃(μ₃-OH)₅(μ₃-OCH ₃)(CH₃OH)₄(H₂O)]·xCH ₃OH·yH₂O (RE = Dy^III, x = 4, y = 4 (1), RE = Gd^III, x = 5, y = 4 (2), RE = Y^III, x = 5, y = 3 (3)). Single-crystal X-ray diffraction reveals that the metal core of each cluster consists of two distorted [RE₂Ni₂O₄] cubane-like moieties and a heterobimetallic triangular [RE₂NiO ₂] unit, with RE ions arranged in a typical triangular fashion. Variable-temperature solid state magnetic susceptibilities of these complexes were measured in the temperature range 2-300 K and the results indicate that an overall ferromagnetic interaction among the metal ions is operative for compounds 2 and 3. Under zero external field, the Dy₃Ni₅ compound shows a frequency dependence of the out-of-phase (χ′′) signals, which indicates slow relaxation of the magnetization.

Full text of DOI:10.1039/c3dt32572e

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Heterometallic octanuclear REIII NiII (RE = DyΙΙΙ, GdΙΙΙ and YΙΙΙ)
3
5
clusters with slow magnetic relaxation for the dysprosium derivative
Huiyu Wang,a, b Hongshan Ke,a Shuang-Yan Lin,a Yang Guo,a Lang Zhao,a* Jinkui Tanga* and Yun-Hui
Lib
5
Received (in XXX, XXX) Xth XXXXXXXXX 200X, Accepted Xth XXXXXXXXX 200X
DOI:
Reactions of rare earth benzoate and nickel perchlorate with Schiff-base ligand, 2-([(2-
hydroxyphenyl)imino]methyl) phenol (H2L), in the presence of triethylamine yielded three
heterobimetallic octanuclear clusters of general formula [RE3Ni5L5(PhCOO)3(µ3-OH)5(µ3-
10 OCH3)(CH3OH)4(H2O)]·xCH3OH·yH2O (RE = DyΙΙΙ, x = 4, y = 4 (1), RE = GdΙΙΙ, x = 5, y = 4 (2), RE =
YΙΙΙ, x = 5, y = 3 (3)). Single-crystal X-ray diffraction reveals that the metal core of each cluster consists
of two distorted [RE2Ni2O4] cubane-like moieties and a heterobimetallic triangular [RE2NiO2] unit, with
RE ions arranged in a typical triangular fashion. Variable-temperature solid state magnetic susceptibilities
of those complexes were performed in the temperature 2-300 K range and the results indicate an overall
15 ferromagnetic interaction among the metal ions is operative for compounds 2 and 3. Under zero external
field, the Dy3Ni5 compound shows a frequency dependence of the out-of-phase (χ'') signals, which
indicates slow relaxation of the magnetization.
Introduction
Since the discovery of slow magnetic relaxation behavior in the
20 Mn12Ac single-molecule magnet (SMM),1 the search for new
molecular aggregates acting as single-molecule magnets (SMMs)
has been the subject of intense research in the light of possible
applications in information storage and quantum computing
devices at a molecular level.2 SMMs can be considered as the
25 classical quantum interface because a few examples have shown
been observed in some DyIII–NiII complexes with various
structures, such as dinuclear DyNi,8a, 8b, 8c, 8d trinuclear Dy2Ni9a, 9b,
9c
11a, 11b, 11c
50
and DyNi2,10 tetranuclear Dy2Ni2
and DyNi3,12
hexanuclear Dy2Ni4,13 even the high-nuclearity Dy6Ni6,14
15
Dy8Ni8 and Dy42Ni10.16 In this context, there is a continuing
need for the synthesis and characterization of new molecules to
enlarge the available database and thus improve the current
quantum tunneling of magnetization3 and quantum phase 55 knowledge of the structure–property relationship in lanthanide
interference,4,5 besides the common action of classical
magnetization hysteresis. More recently, due to their large spin
multiplicity and large magnetic anisotropies in the ground state,
30 the introduction of heavy lanthanide ions has become an effective
containing SMMs.
Herein, as part of our efforts in this context, we have
successfully obtained a new REIII–NiII complex with a novel
octanuclear RE3Ni5 structure, Dy3Ni5(1), which consists of two
approach to the achievement of SMMs.6a, 6b, 6c For this reason, the 60 distorted [Dy2Ni2O4] cubane-like moieties and a heterobimetallic
studies on mixed 3d–4f complexes that incorporated with heavy
lanthanide (4f) and first-row transition-metal (3d) ions are much
significant from the synthetic and theoretical viewpoint. The
35 introduction of highly anisotropic 4f ions into an exchange-
triangular [Dy2NiO2] unit with Dy ions arranged in a typical
triangular fashion. To the best of our knowledge, this is the first
observation of
a single Dy3 triangle in heterometallic
dysprosium(III)–nickel(II) complexes showing slow magnetic
coupled molecular 3d system may enhance the SMM behavior, 65 relaxation. The structural features of this compound are
due to the combination of single-ion anisotropy and 3d–4f
interactions. Based on this consideration, mixed 3d–4f SMMs
with higher blocking temperatures and higher energy barriers
40 have been obtained as expected.7a, 7b, 7c, 7d On the other hand, to
obtain new types of 3d–4f SMMs is also a continued research
topic in the field of molecular magnetic materials. Considering
the single-ion anisotropies of dysprosium(III) and nickel(II) ions,
heterometallic dysprosium(III)–nickel(II) complexes have
45 attracted much attention, despite the fact that nickel(II) ions do
not manifest its magnetic anisotropy as expected in these
compounds. To date, slow relaxation of the magnetization have
reminiscent of those reported for a Dy3Cu6 cluster17 and Dy3Mn6
cluster18 but they show differences in magnetic properties. In
addition, we have also synthesized the corresponding Gd3Ni5 (2)
and Y3Ni5 (3) complexes in order to study their magneto-
70 structural relations.
Experimental section
Synthesis of H2L.
2-([(2-hydroxyphenyl)imino] methy) phenol was synthesized by
the condensation of the 2-hydroxybenzaldehyde and 2-
This journal is © The Royal Society of Chemistry [year]
[journal], [year], [vol], 00–00 | 1

aminophenol in a 1:1 molar ratio under stirring at 80–100°C as a
reported method.19 There are two coordination modes of ligand
(H2L) in the clusters. Meanwhile, all the five ligands display two
chelating/bridging modes (η2:η1:η2-μ3 and η3:η1:η1-μ3) as shown
in Scheme. 1.
carried out on a Perkin-Elmer 2400 analyzer. FTIR spectra were
Table 1. Summary of crystal data for clusters 1-3
View Article Online
1
2
3
5
formula
Mr
C95H110Dy3N5Ni5O35C98H114Gd3N5Ni5O34C 96H112Y3N5Ni5O35
2662.93 2671.24 2456.19
cryst size [mm]0.20 × 0.16 × 0.12 0.20 × 0.18 × 0.14 0.22 × 0.16 × 0.14
color
brown blocks
Triclinic
brown blocks
Triclinic
P-1
brown blocks
Triclinic
P-1
cryst. syst.
space group P-1
T [K]
a [Å]
b [Å]
c [Å]
α [deg]
β [deg]
γ [deg]
V [Å 3]
Z
185(2)
185(2)
185(2)
14.25(11)
16.85(14)
24.63(2)
90.00°(10)
101.46°(10)
111.43°(10)
5374.5(7)
2
14.20(11)
16.85(14)
24.86(2)
90.00°(10)
101.26°(10)
111.49°(10)
5414.2(7)
2
14.18 (8)
16.71(9)
24.75(14)
90.40° (10)
101.49°(10)
111.23°(10)
5337.5(5)
2
Scheme 1 Binding modes of the ligand H2L: η2:η1:η2-μ3 (a) and η3:η1:η1-
μ3 (b).
Syntheses of compounds 1-3
10 [Dy3Ni5L5(PhCOO)3(µ3-OH)5(µ3-
OCH3)(CH3OH)4(H2O)]·4CH3OH·4H2O (1):
A
methanol
solution of Dy(PhCOO)3 (0.10 mmol, 0.0536 g) was added to the
Schiff-base ligand H2L (0.11 mmol, 0.0214 g) dissolved in 10
mL of methanol. The reaction mixture was stirred for 30 min,
15 then added Ni(ClO4)2·6H2O (0.0443 g, 0.12 mmol) and
triethylamine (0.3 mmol), and the resulting deep-yellow solution
was stirred for 3 h. Block brown single crystals suitable for X-ray
diffraction were obtained after six days. Yield: 32 mg, (50%,
based on the nickel salt). Elemental analysis (%) calcd for
20 C96H112Dy3N5Ni5O35: C, 42.85, H, 4.16, N, 2.63; found: C, 42.42,
H, 3.65, N, 2.62. IR (KBr, cm-1): 3351 (br), 3059 (m), 1596 (s),
1542 (s), 1467 (s), 1440 (s), 1386 (m), 1332 (w), 1297 (m), 1243
(m), 1220 (w), 1172 (m), 1151 (m), 1126 (w), 1070 (w), 1038
(w), 961 (w), 920 (m), 827 (m), 746 (s), 720 (s), 675 (m), 549
25 (w).
Dcalcd [g cm-3] 1.646
1.639
1.528
μ(Mo Kα)
2.994
2.739
2.554
[mm-1]
F(000)
2666
2682
2520
reflns collected30029
unique reflns 21225
30431
21304
0.0284
27324
18713
0.0531
Rint
0.0355
Parameters
/restraints
1314 / 666
1329/ 33
1297 / 57
GOF
1.047
1.058
1.042
0.0658
0.0557
0.1803
0.0840
0.2783
R1 [I > 2σ(I)]
wR2 (all data) 0.2151
largest diff.
[Gd3Ni5L5(PhCOO)3(µ3-OH)5(µ3-
OCH3)(CH3OH)4(H2O)]·5CH3OH·4H2O (2):
3.088 and -1.324 2.726 and -1.213 1.790 and -0.805
peak/hole[eÅ-3]
A
similar
synthetic procedure as that for 1 was used to synthesize 2 except
that Dy(PhCOO)3 was replaced by Gd(PhCOO)3 (0.101 mmol,
30 0.0457 g). Yield: 30 mg, (47%, based on the nickel salt).
Elemental analysis (%) calcd for C97H118Gd3N5Ni5O36: C, 44.06,
H, 4.30, N, 2.62; found: C, 42.75, H, 3.65, N, 2.59. IR (KBr, cm-
1): 3367 (br), 3060 (m), 1596 (s), 1541 (s), 1467 (s), 1440 (s),
1386 (m), 1333 (w), 1300 (m), 1244 (m), 1220 (w), 1172 (m),
35 1151 (m), 1126 (w), 1070 (w), 1038 (w), 961 (w), 920 (m), 827
(m), 746 (s), 721 (s), 675 (m), 549 (w).
recorded with
a Perkin-Elmer Fourier transform infrared
55 spectrophotometer using the reflectance technique (4000–300 cm-
1). Samples were prepared as KBr disks. All magnetization data
were recorded on a Quantum Design MPMS-XL7 SQUID
magnetometer. The variable-temperature magnetization was
measured with an external magnetic field of 1000 Oe in the
60 temperature range of 2-300 K. The experimental magnetic
susceptibility data are corrected for the diamagnetism estimated
from Pascal’s tables and sample holder calibration.
[Y3Ni5L5(PhCOO)3(µ3-OH)5(µ3-
OCH3)(CH3OH)4(H2O)]·5CH3OH·3H2O (3):
X-Ray crystal structure determinations
A
similar
synthetic procedure as that for 1 was used to synthesize 3 except
40 that Dy(PhCOO)3 was replaced by Y(PhCOO)3 (0.102 mmol,
0.0532 g). Yield: 29 mg, (51%, based on the nickel salt).
Elemental analysis (%) calcd for C96H112Y3N5Ni5O35: C, 46.95,
H, 4.60, N, 2.85; found: C, 47.2, H, 4.34, N, 2.93. IR (KBr, cm-
1): 3367 (br), 3060 (m), 1597 (s), 1541 (s), 1467 (s), 1440 (s),
45 1386 (m), 1333 (w), 1300 (m), 1244 (m), 1220 (w), 1172 (m),
1151 (m), 1126 (w), 1070 (w), 1038 (w), 961 (w), 920 (m), 827
(m), 746 (s), 721 (s), 675 (m), 550 (w).
X-Ray crystal structure determination suitable single crystals
65 with dimensions of 0.20 × 0.16 × 0.12, 0.20 × 0.18 × 0.14 and
0.22 × 0.16 × 0.14 mm3 for 1, 2 and 3 were selected for single-
crystal X-ray diffraction analysis. Crystallographic data were
collected at a temperature of 185(2) K on a Bruker Apex II CCD
diffractometer with graphite monochromated Mo-Kα radiation (λ
70 = 0.71073 Å). Data processing was performed with SAINT
processing program. The structures were solved by direct
methods and refined on F2 with the full matrix least squares
methods by SHELXTL-97.20 The locations of the metal atoms
Physical measurements
were easily determined, and O, N, and
C atoms were
All chemicals were used as commercially obtained without
50 further purification. Elemental analysis for C, H, and N were
75 subsequently determined from the difference Fourier maps. All
non-hydrogen atoms were refined with anisotropic thermal
2
|
Journal Name, [year], [vol], 00–00
This journal is © The Royal Society of Chemistry [year]

parameters. The H atoms were introduced in calculated positions
and refined with fixed geometry with respect to their carrier
atoms. CCDC 893629 (1), 893630 (2) and 893631 (3) contain the
supplementary crystallographic data for this paper. These data
can be obtained free of charge from the Cambridge
Crystallographic Data Centre via www.ccdc.cam.ac.uk/data
request/cif.
groups and two bridging phenoxide groups of the ligand L2-, plus
one water molecule for Dy1 and one methanol molecule for Dy2
View Article Online
5
Results and discussion
Single-crystal X-ray diffraction reveals that clusters 1, 2 and 3
45
10 are isostructural and all crystallize in the triclinic space group P-1
(Table 1), therefore, a full description of the structure of 1 is
described here as a representative.
17
Fig. 2 The main framework of [Dy3Cu6] obtained by Luneau et al (a)
and [Dy3Ni5] (b).
Fig. 3 The [Dy2Ni2O4] cubane-like moietiy (a) and [Dy2NiO2] moiety (b).
50 and Dy3, exhibiting a relatively perfect dicapped trigonal-
prismatic geometry (Fig. 4). Consistent with normal range,21 the
Dy-O bond lengths are in the range 2.283(7)-2.484(7) Å, with the
longest Dy3-O13 (2.484(7) Å) and the shortest Dy2-O18
(2.283(7) Å). The Dy-O-Dy and Ni-O-Dy angles range from
55 105.1(2) to 108.1(3)o and 86.1(2) to 110.2(3)o, respectively.
Fig. 1 Structure of the cluster 1 with selective numbering scheme.
15
The crystal structure of 1 consists of neutral entities
[Dy3Ni5L5(PhCOO)3(µ3-OH)5(µ3-OCH3)(CH3OH)4(H2O)] (Fig.
1), and water molecules and methanol molecules for
crystallization. In comparison with the Dy3Cu6 cluster obtained
by Luneau et al,17 for which the cluster is built from three DyIII
20 ions arranged in a triangular fashion with [Cu2] dimer units on
each edge of the Dy3 triangle (Fig. 2(a)) , two [Ni2] dimer units
and one [Ni] monomer locate on the edge of the Dy3 triangle in 1
(Fig. 2(b)). Alternatively, the main framework can be described
as the fusion of two distorted [Dy2Ni2O4] cubane-like moieties
25 (Fig. 3(a)) and a heterobimetallic triangular [Dy2NiO2] moiety
(Fig. 3(b)) that share the Dy ions in a triangular fashion. In
[Dy2Ni2O4] cubane-like moieties (Fig. 3(a)), two DyIII ions are
connected to two NiII ions by two µ3-OH- groups and two
phenoxido groups µ3-O atoms of the ligands. In addition,
30 benzoate ligands connect Dy1 and Ni5, Dy2 and Ni2, as well as
Dy3 and Ni4 in syn-syn η1:η1-μ2 form, further consolidating this
heterometallic cubane. Heterobimetallic triangular [Dy2NiO2]
moiety (Fig. 3(b)) is capped above and below by one µ3-OH- and
one μ3-OCH3 group and two Dy-Ni edges of triangle are
35 connected by two µ2-Ophenoxido groups of the ligand. Although the
different moieties are around the [Dy3O6] compared with the
Dy3Cu6 cluster, the [Dy3Ni5] also forms a near equilateral Dy3
triangle with Dy···Dy distances of 3.5762(6), 3.5838(6) and
3.5486(7) Å.
Fig. 4 Coordination modes of three DyIII ions.
Unlike the five- or six- coordinate CuII ions in the Dy3Cu6
cluster, the five NiII ions all have the six-coordinate NO5
60 environment with a distorted octahedral geometry in similar
form: the basal plane is made up of two oxygen atoms and one
nitrogen atom from the ligand L2- and one µ3-OH oxygen atom;
the axial position is occupied by µ3-Ophenoxido of the ligands L2-
and μ3-OMe for Ni1, methanol molecule and μ3-OMe for Ni3, µ3-
65 Ophenoxido of the ligands L2- and one oxygen atom of benzoate
ligand for Ni2 and Ni4 and Ni5 ions. Additionally, there are no
obvious irregularities in the Ni−N and Ni−O bond lengths, these
distances are in the ranges 1.959(8)-2.000(18) and 1.976(7)-
2.313(6) Å, respectively.
40
The three DyIII ions are all eight-coordinate environment, as
the DyIII ions in the Dy3Cu6 cluster.17 Each DyIII ion is
coordinated by four bridging OH groups, one bridging benzoate
70 Magnetic properties
Given low symmetry in clusters 1, 2 and 3 compared with
This journal is © The Royal Society of Chemistry [year]
Journal Name, [year], [vol], 00–00 | 3

2
2
2
2
2
ˆ
ˆ
ˆ
ˆ
ˆ
Dy3Cu6 cluster, we study the magnetic of three clusters to reveal
the influence of the structure on the properties. The temperature
dependence of the direct current (dc) magnetic susceptibilities of
clusters 1, 2 and 3 were measured under 1000 Oe magnetic field
in the 2-300 K temperature range. The results are depicted in Fig.
5 as χMT versus T curve (χM being the molar magnetic
susceptibility per RE3Ni5 unit). For 1, the product of χMT at room
temperature is 46.25 cm3 K mol-1, which is close to the expected
value of 48.51 cm3 K mol-1 for five independent NiII ions (S = 1,
H = −2J1(SNi1 ⋅SNi2 ) − 2J2 (SNi4 ⋅SNi5 ) + D(SNi1 + SNi2 + SNi3 + SNi4 + SNi5 )
where J1 represents interaction between Ni1 and NVi2ie,wwAhrtiicllee OJn2line
50 represents interaction between Ni4 and Ni5. The best fit is
obtained with values of J1 = 7.6 cm-1, J2 = 6.2 cm-1, g = 2.19, D =
19.1 cm-1. It is worth noting that J1 is slightly larger than J2 may
be due to the minor differences of the Ni-O-Ni angle.
5
10 C = 1.20 cm3 K mol-1 with g = 2.19) and three DyIII ions (J =
15/2, S = 5/2, g = 4/3,C = 14.17 cm3 K mol-1). The χMT product
gradually decreases until 50 K and then further drops to reach a
minimum of 30.55 cm3 K mol-1 at 2 K. The decline in χMT is
likely due to a combination of the progressive depopulation of
6
15 DyIII excited Stark sublevels (Stark sublevels of the H15/2 state)
and possible exchange interaction between the metal ions.
However, it is difficult to comment on the interactions of Ni···Dy
and Dy···Dy in 1, with lanthanide ions having intrinsic
complicated magnetic characteristics, which include the presence
20 of spin-orbit coupling and magnetic anisotropy.22
55 Fig. 6 M vs. H plot at 2 K for Dy3Ni51 (□), Gd3Ni52 (○) and Y3Ni53 (△).
For 2, the χMT value of 31.07 cm3 K mol-1 at room temperature
is close to 29.63 cm3 K mol-1 expected for five NiII ions (S = 1, C
= 1.20 cm3 K mol-1 with g = 2.19) and three GdIII ions (J = 7/2, S
= 7/2, g = 2.0, C = 7.875 cm3 K mol-1). Upon cooling, the χMT
25 value gradually increases to 32.94 cm3 K mol-1 at 50 K and then
rapidly increases to 53.19 cm3 K mol-1 at 2 K, suggesting an
overall ferromagnetic interaction among the metal ions is
operative. The ferromagnetic interaction in 2 is in contrast to
antiferromagnetic interactions in the reported RE3Mn6 cluster
30 with the same Gd3 motif.18 However, due to the large size of the
Hamiltonian matrix, efforts to extract the exchange coupling
constants by fitting the experimental magnetic susceptibility data
for 2 with eight paramagnetic centers were not successful.
Magnetization experiments for clusters 1-3 were carried out in
the 0-7 T field range (Fig. 6). For 1, the magnetization increases
smoothly with increasing applied dc field, and reaches the value
of 27.10 μB at 2 K and without any sign of saturation even at 7 T,
60 which can be attributed to anisotropy of the DyIII and the
presence of weak magnetic interactions that make the low-lying
excited states accessible. Furthermore, the non-superimposed M
vs. H/T curves confirm the presence of anisotropy and/or low-
lying excited states as expected for clusters containing
65 anisotropic DyIII and/or NiII ions (Fig. 7).
Fig. 7 M vs. H/T plot for cluster 1.
For 2, the field dependence of the magnetization (M) at low
temperatures shows that the magnetization increases with the
70 applied dc field (H) to approach a clear saturation at 7 T with the
value of 30.16 μB (Fig. 6), indicative of a low magnetic
anisotropy, as is expected for isotropic systems. Moreover, the
magnetization value of cluster 3 gradually increases to 8.05 μB at
2 K and 7 T, close to the saturation as expected.
35 Fig. 5 Temperature dependence of the χMT product at 1000 Oe for
Dy3Ni51 (□), Gd3Ni52 (○) and Y3Ni53 (△).
For 3, there is no contribution from the diamagnetic YIII ion
and the χMT product at room temperature of 6.16 cm3 K mol-1 is
in agreement with the calculated value of 6.00 cm3 K mol-1
40 expected for five NiII ions (S = 1, C = 1.20 cm3 K mol-1 with g =
2.19). Upon cooling, the χMT value gradually increases to the
maximum value 7.66 cm3 K mol-1 at 30 K, due to ferromagnetic
interactions between NiII ions. Then rapidly decreases to 2.07 cm3
K mol-1 at 2 K, which is probably associated to the zero-field
45 splitting effect of the NiII ions. To analyze the magnetic
susceptibility data of 3, we have employed a simple model with
the following spin Hamiltonian,
75
In view of the SMM behavior of Dy3Cu6 cluster and the
significant anisotropy inherent to DyIII, alternating-current (ac)
magnetic susceptibility measurements were performed under zero
static field to probe the dynamics of magnetization for cluster 1.
As shown in Fig. 8, the low-temperature ac susceptibility shows
80 appearance of an out-of-phase signal below 4 K indicating the
4
|
Journal Name, [year], [vol], 00–00
This journal is © The Royal Society of Chemistry [year]

45 †CCDC reference numbers 893629-893631. For ESI and crystallographic
data in CIF or other electronic format see www.ccdc.cam.ac.uk/data
onset of slow magnetization relaxation, which is typical for SMM
behavior. The absence of frequency-dependent peaks in out-of-
phase susceptibility may be caused by the presence of a relatively
fast zero-field relaxation. These behaviors suggest 1 is possibly a
3d-4f SMM but one with a rather small relaxation barrier.
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Fig. 8 Frequency dependence of the out-of-phase (χ'') signals at different
frequencies of 1 under zero external field.
In contrast to the slow relaxation observed in 1, no out-of-
10 phase ac signal is noticed for the cluster 2 and 3. Therefore, slow
magnetic relaxation of 1 arises mainly from the presence of
anisotropic DyIII ions. Nevertheless, the intramolecular magnetic
interactions as a secondary consideration may also mediate the
magnetic relaxation of 3d-4f based magnetic clusters.
15 Conclusions
In summary, we have successfully obtained three heterometallic
RE-Ni clusters based on the Schiff-base ligand H2L. The metal
core of each cluster consists of two distorted [RE2Ni2O4] cubane-
like moieties and a heterobimetallic triangular [RE2NiO2] unit
9. (a) F. Mori, T. Ishida and T. Nogami, Polyhedron, 2005, 24, 2588-
2592; (b) F. Pointillart, K. Bernot, R. Sessoli and D. Gatteschi,
Chem.–Eur. J., 2007, 13, 1602-1609; (c) A. Okazawa, T. Nogami, H.
Nojiri and T. Ishida, Inorg. Chem., 2008, 47, 9763-9765.
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Vittal, A. Houri and R. Clérac, Inorg. Chem., 2008, 47, 4918-4929.
20 with RE ions arranged in
a typical triangular fashion.
Investigation on their magnetic property shows ferromagnetic
interactions in 2 and 3. Ac susceptibility measurements reveal
that only cluster 1 exhibits out-of-phase ac signal at different
frequencies in zero external field, indicating slow relaxation of
25 the magnetization. Comparison of the Dy3Cu6 cluster , RE3Mn6
clusters and cluster 1 suggest that some changes in structure have
a great influence on the magnetic property, despite the different
transition metal. Further experiments are underway to synthesize
RE3Ni6 and RE3Cu5 clusters and thoroughly analyze the
30 structural and magnetic property relationship. This synthetic
approach may represent a promising new route toward the design
of novel 3d-4f clusters and new magnetic materials.
85 11. (a) T. D. Pasatoiu, M. Etienne, A. M. Madalan, M. Andruh and R.
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90
11604-11611.
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2705.
95
14. Y.-Z. Zheng, M. Evangelisti and R. E. P. Winpenny, Angew. Chem.
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Chem., 2010, 49, 9743-9745.
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Jacquot and D. Luneau, Angew. Chem. Int. Ed., 2006, 45, 4659-4662.
18. X.-J. K. Yong Zheng, La-Sheng Long, Rong-Bin Huang and Lan-
Sun Zheng, Dalton Trans., 2011, 40, 4035-4037.
100
105
Acknowledgements
This work was supported by the National Natural Science
35 Foundation of China (Grants 21201160, 21221061, 91022009
and 21241006) for its financial support.
Notes and references
19. Y. Elerman, A. Elmali, O. Atakol, I. Svoboda, Acta Crystallogr. Sec.
C, 1995, 51, 2344-2346.
110 20. G. M. Sheldrick, Acta Crystallogr. Sec. A, 2008, 64, 112-122.
21. R. D. Shannon, Acta Crystallogr. Sect. A, 1976, 32, 751-767.
22. X.-Q. Zhao, Y. Lan, B. Zhao, P. Cheng, C. E. Anson and A. K.
Powell, Dalton Trans., 2010, 39, 4911-4917.
aState Key Laboratory of Rare Earth Resource Utilization, Changchun
Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun
40 130022, People’s Republic of China, Fax:(+)86-431-85262878; E-mail:
tang@ciac.jl.cn.
bSchool of Chemistry and Environmental Engineering ,Changchun
University of Science and Technology, Changchun, People’s Republic of
China.
This journal is © The Royal Society of Chemistry [year]
Journal Name, [year], [vol], 00–00 | 5

Graphical Abstract
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The reactions of rare earth benzoate and nickel perchlorate with
Schiff-base ligand afford three heterometallic octanuclear clusters
[RE3Ni5] with RE ions arranged in a typical triangular fashion.
The Dy3Ni5 cluster showing a frequency dependency of the out-
of-phase (χ'') signals indicates slow relaxation of the
magnetization.
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Journal Name, [year], [vol], 00–00
This journal is © The Royal Society of Chemistry [year]