Syntheses, structures and magnetism of four Ni(II)/Co(II) interpenetrating coordination polymers based on 1,4-bis(4-(imidazole-1-yl)benzyl)piperazine

Article abstract of DOI:10.1016/j.ica.2016.07.001

Four novel interpenetrating coordination polymers have been hydrothermally synthesized based on a long flexible N-donor ligand (bibp) and different polycarboxylates, namely [Ni(1,3-bdc)(bibp)(H₂O)]·0.5H₂O (1), [Ni(btec)_0.5

Full text of DOI:10.1016/j.ica.2016.07.001

Inorganica Chimica Acta 451 (2016) 1–7
Contents lists available at ScienceDirect
Inorganica Chimica Acta
journal homepage: www.elsevier.com/locate/ica
Research paper
Syntheses, structures and magnetism of four Ni(II)/Co(II)
interpenetrating coordination polymers based on 1,4-bis(4-(imidazole-
1-yl)benzyl)piperazine
Yu Chen a, Xi-Chi Wang a, Yu-Ci Xu a, Hui-Ling Xu a, Hao Yuan a, Jin-Tao Tong a, Dong-Rong Xiao a,b,
⇑
a College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China
b State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Four novel interpenetrating coordination polymers have been hydrothermally synthesized based on a
long flexible N-donor ligand (bibp) and different polycarboxylates, namely [Ni(1,3-bdc)(bibp)(H2O)]ꢀ
0.5H2O (1), [Ni(btec)0.5(bibp)1.5]ꢀH2O (2), [Co(btec)0.5(bibp)1.5]ꢀH2O (3) and [Co(oba)(bibp)]ꢀ2H2O (4)
(bibp = 1,4-bis(4-(imidazole-1-yl)benzyl)piperazine, 1,3-bdc = 1,3-benzenedicarboxylate, btec = 1,2,4,5-
benzenetetracarboxylate, oba = 4,40-oxybisbenzoate). Their structures were determined by single-crystal
X-ray diffraction analyses and further characterized by elemental analyses, IR spectra and TG analyses.
Compound 1 shows a 2-fold interpenetrating 3D framework with CdSO4 topology. Compounds 2 and 3
exhibit 2-fold interpenetrating pcu frameworks. Compound 4 is a 2D ? 3D interdigitated network
formed from 2D ? 2D threefold interpenetrating motifs. In addition, the magnetic properties of com-
pounds 1–4 have also been investigated in the temperature range 2–300 K.
Received 8 April 2016
Received in revised form 16 June 2016
Accepted 1 July 2016
Keywords:
Coordination polymer
Interpenetration
N-containing ligand
Magnetic property
Ó 2016 Elsevier B.V. All rights reserved.
1. Introduction
flexible linear N-donor ligands, considered as an attractive kind
of organic ligands, have successfully built some interpenetrating
In the last decade, fascinating structures and diverse topologies
of coordination polymers (CPs) have received a great deal of atten-
tion [1]. Moreover, CPs have emerged as powerful platforms for
exploring potential applications, such as gas adsorption and sepa-
ration [2], catalysis [3], sensors [4], nonlinear optics [5] and mag-
netic materials [6]. Among the various coordination polymers,
entangled systems have attracted particular attention owing to
its intricate framework topologies [7]. Interpenetrating networks,
as an important subgroup of entangled systems, have been exten-
sively investigated [8]. There is a common characteristic feature of
interpenetrating networks, that is, the individual nets cannot be
separated until internal connections are broken [7b,7c]. Currently,
the synthesis and the modulation on the molecular level aimed at
attaining desirable interpenetrating structures, however, still
remain outstanding challenges.
structures. For example, Ciani and co-workers have synthesized a
series of interpenetrating dia networks with 1,12-dodecanedini-
trile [10]; our group has utilized 1,4-bis(imidazol-1-yl)butane to
obtain a 2-fold interpenetrating framework with CdSO4 topology
[11]; Fan et al. have reported a threefold interpenetrating 3D
framework with a 6-c {312ꢀ428ꢀ55} topology using 1,3-bis(4-pyri-
dyl)propane [12]. It is worthy to be mentioned that long flexible
linear N-donor ligands have great potential to fabricate intriguing
interpenetrating structures for the followed merits: (i) The flexibil-
ity of these ligands whose –CH2– (alkyl) groups enable to bend and
rotate freely leads to different conformation geometries which can
easily meet the coordination nature of metal cations. (ii) Usually,
long organic ligands will lead to large voids which may thus favor
the formation of interpenetrating networks [13]. Therefore, choos-
ing long flexible linear N-donor ligands is regarded as a feasible
proposal to construct new interpenetrating networks [14].
During the synthesis course, a long flexible N-containing ligand,
named bibp was firstly synthesized, and then reacted with
different polycarboxylates and nickel/cobalt acetate. These
efforts have led to the isolation of four new interpenetrating coor-
dination polymers, namely [Ni(1,3-bdc)(bibp)(H2O)]ꢀ0.5H2O (1),
[Ni(btec)0.5(bibp)1.5]ꢀH2O (2), [Co(btec)0.5(bibp)1.5]ꢀH2O (3) and
[Co(oba)(bibp)] ꢀ2H2O (4) (1,3-bdc = 1,3-benzenedicarboxylate,
In most cases, the factors, such as templates, the solvent sys-
tems, pH value of solution, organic ligands, the metal-ligand ratio,
coordination geometry of the metal ions can influence the struc-
tures and topologies of products [9]. Among these factors, long
⇑
Corresponding author at: College of Chemistry and Chemical Engineering,
Southwest University, Chongqing 400715, PR China.
E-mail address: xiaodr98@swu.edu.cn (D.-R. Xiao).
http://dx.doi.org/10.1016/j.ica.2016.07.001
0020-1693/Ó 2016 Elsevier B.V. All rights reserved.

2
Y. Chen et al. / Inorganica Chimica Acta 451 (2016) 1–7
btec = 1,2,4,5-benzenetetracarboxylate, oba = 4,40-oxybisbenzoate,
Scheme 1). The syntheses, crystal structures and the magnetic
properties of these compounds will be represented and discussed
in this paper.
2.3. Synthesis of [Ni(btec)0.5(bibp)1.5]ꢀH2O (2)
A mixture of Ni(Ac)2ꢀ4H2O (0.050 g, 0.2 mmol), H4btec (0.025 g,
0.1 mmol), bibp (0.040 g, 0.1 mmol), Et3N (0.10 mL) and distilled
water (10 mL) was stirred about 15 min in air, then transferred
and sealed in a 17 mL Teflon-lined autoclave, which was heated
at 160 °C for 72 h. After slow cooling to room temperature, green
plank crystals of 2 were filtered off, washed with distilled water,
and dried at ambient temperature (yield: 31% based on Ni). Ele-
mental analysis (%) calcd for C41H42NiN9O5: C, 61.59; H, 5.29; N,
15.77; Ni, 7.34%. Found: C, 61.78; H, 5.15; N, 15.95; Ni, 7.14%.
FT/IR data (cmꢁ1): 3418(br), 3167(w), 3132(w), 3044(w), 2932
(w), 2873(w), 2808(m), 2767(m), 1611(s), 1566(s), 1524(s), 1484
(m), 1430(w), 1366(s), 1300(s), 1265(m), 1245(w), 1183(w), 1151
(w), 1129(w), 1066(m), 1006(w), 962(w), 926(w), 850(m), 808
(m), 777(w), 730(w), 653(w), 624(w), 570(w), 527(w), 423(w).
2. Experimental
2.1. Materials and general methods
The bibp ligand was synthesized according to the procedures in
Electronic Supplementary information. Other reagents and sol-
vents were obtained from commercial suppliers and used without
further purification.
Elemental analyses (C, H and N) were performed on a Perkin-
Elmer 2400 CHN Elemental Analyzer. Ni and Co were determined
by a tps-7000 Plasma-Spec(I) inductively coupled plasma-atomic
emission spectrometer (ICP-AES). IR spectra were recorded in the
range 400–4000 cmꢁ1 on a Bio-Rad FTS-185 FT/IR Spectropho-
tometer using KBr pellets. TG analyses were performed on a
NETZSCH STA 449C instrument in flowing N2 with a heating rate
of 10 °C minꢁ1. PXRD data were recorded on a XD-3 diffractometer
2.4. Synthesis of [Co(btec)0.5(bibp)1.5]ꢀH2O (3)
The preparation of 3 was similar to that of 2 except that Co
(Ac)2ꢀ4H2O was used instead of Ni(Ac)2ꢀ4H2O and a change in the
dosage of Et3N (0.25 mL). Pink plank crystals of 3 were collected
(yield: 21% based on Co). Elemental analysis (%) calcd for
using Cu Ka radiation. Variable-temperature magnetic susceptibil-
ity data were obtained on a SQUID magnetometer (Quantum
Design, MPMS-7) in the temperature range of 2–300 K with an
applied field of 1.0 kOe. All the magnetic susceptibility data were
corrected from diamagnetic contributions estimated from Pascal’s
constants.
C
41H42CoN9O5: C, 61.57; H, 5.29; N, 15.76; Co, 7.37%. Found: C,
61.80; H, 5.09; N, 15.98; Co, 7.12%. FT/IR data (cmꢁ1): 3417(br),
3161(w), 3131(w), 2934(w), 2873(w), 2807(m), 2767(w), 1611(s),
1567(s), 1523(s), 1484(m), 1368(s), 1300(s), 1264(m), 1183(w),
1153(w), 1131(w), 1065(m), 1007(w), 962(w), 927(w), 851(m),
809(m), 774(w), 730(w), 653(w), 623(w), 576(w), 529(w), 423(w).
2.2. Synthesis of [Ni(1,3-bdc)(bibp)(H2O)]ꢀ0.5H2O (1)
2.5. Synthesis of [Co(oba)(bibp)]ꢀ2H2O (4)
A
mixture of Ni(Ac)2ꢀ4H2O (0.050 g, 0.2 mmol), 1,3-H2bdc
(0.017 g, 0.1 mmol), bibp (0.040 g, 0.1 mmol), Et3N (0.10 mL) and
distilled water (10 mL) was stirred about 15 min in air, then trans-
ferred and sealed in a 17 mL Teflon-lined autoclave, which was
heated at 160 °C for 48 h. After slow cooling to room temperature,
green octahedral crystals of 1 were filtered off, washed with dis-
tilled water, and dried at ambient temperature (yield: 45% based
on Ni). Elemental analysis (%) calcd for C32H33NiN6O5.5: C, 59.28;
H, 5.13; N, 12.96; Ni, 9.05%. Found: C, 59.57; H, 4.89; N, 12.79;
Ni, 9.31%. FT/IR data (cmꢁ1): 3436(br), 3110(w), 2923(w), 2889
(w), 2840(w), 1602(s), 1546(s), 1522(s), 1479(m), 1446(s), 1383
(s), 1343(w), 1304(s), 1263(m), 1247(w), 1177(w), 1117(m), 1064
(m), 996(m), 962(w), 929(w), 902(w), 847(m), 807(m), 745(m),
719(m), 655(m), 630(w), 571(w), 526(w), 457(w), 431(w).
A mixture of Co(Ac)2ꢀ4H2O (0.100 g, 0.4 mmol)ꢀH2oba (0.104 g,
0.4 mmol), bibp (0.160 g, 0.4 mmol), Et3N (0.25 mL) and distilled
water (10 mL) was stirred about 15 min in air, then transferred
and sealed in a 17 mL Teflon-lined autoclave, which was heated
at 160 °C for 72 h. After slow cooling to room temperature, purple
plank crystals of 4 were filtered off, washed with distilled water,
and dried at ambient temperature (yield: 76% based on Co). Ele-
mental analysis (%) calcd for C38H38CoN6O7: C, 60.88; H, 5.11; N,
11.21; Co, 7.86%. Found: C, 61.10; H, 5.34; N, 10.99; Co, 7.63%.
FT/IR data (cmꢁ1): 3402(w), 3118(m), 3069(w), 2937(w), 2817
(m), 2774(w), 1599(s), 1567(s), 1526(s), 1498(w), 1460(w), 1418
(m), 1377(s), 1301(m), 1240(s), 1157(m), 1126(m), 1096(w),
1062(m), 1007(w), 963(w), 938(w), 877(m), 852(m), 807(m), 781
(m), 728(w), 700(w), 657(m), 557(w), 525(w), 464(w), 427(w).
2.6. X-ray crystallography
Single-crystal X-ray diffaction data for 1–3 were collected using
an Agilent Technologies SuperNova Dual diffractometer with Cu K
a
radiation (k = 1.54184 Å) at 291.08 K. Single-crystal X-ray diffac-
tion data for 4 were collected using a Bruker Smart Apex CCD
diffractometer with Mo K
a radiation (k = 0.71073 Å) at 296.15 K.
Using Olex2 [15], the structures of 1–3 were solved with the Super-
flip [16] structure solution program using Charge Flipping and the
structure of 4 was solved with the ShelXS [17] structure solution
program using Direct Methods. Moreover, the structures of 1–4
were refined with the ShelXL [18] refinement package using Least
Square minimization. The non-hydrogen atoms were refined
anisotropically. The organic hydrogen atoms were generated geo-
metrically. A part of aqua hydrogen atoms in compounds 1 and 4
could not positioned from difference Fourier maps. Other aqua
hydrogen atoms were located from difference Fourier maps and
refined with isotropic displacement parameters. The detailed
crystallographic data and structure refinement parameters for
Scheme 1. Schematic drawing of (a) bibp, (b) 1,3-H2bdc, (c) H4btec and (d) H2oba
ligands.

Y. Chen et al. / Inorganica Chimica Acta 451 (2016) 1–7
3
compounds 1–4 are summarized in Table 1. Selected bond lengths
for 1–4 are listed in Table S1. The topological analyses were done
with the TOPOS program [19].
bibp ligands and one free water molecule. As shown in Fig. 2a,
the coordination environment around Ni1 can be described as a
slightly distorted octahedral geometry, being coordinated by three
carboxylate oxygen atoms (Ni–O 2.056(11)–2.076(10) Å) from two
different btec ligands and three nitrogen atoms (Ni–N 2.085(13)–
2.158(13) Å) from three different bibp ligands. The four carboxylic
groups of btec ligand exhibit monodentate and bis(monodentate)
coordination modes to bind four Ni(II) cations (mode II,
Scheme S3), and each bibp ligand acts as a linear ligand interlink-
ing two Ni atoms (Scheme S2). For convenience, the bibp ligands
containing N5 and N1 are designated bibp0 and bibp00, respectively.
In this way, the Ni atoms are connected by btec and bibp0 ligands to
furnish 2D double layers (Fig. S2). Then the bibp00 ligands act as pil-
lars residing in the interlayer regions and join adjacent 2D double
layers together, to generate a 3D open framework with large
channels (Fig. 2b). Topologically, if each binuclear Ni cluster
({Ni2(OCO)2}: two Ni atoms connected by two carboxylate groups)
is reduced to a 6-connected node, the structure can be simplified as
a pcu network (Fig. 2c).
3. Results and discussion
3.1. Description of crystal structures
3.1.1. Structure of [Ni(1,3-bdc)(bibp)(H2O)]ꢀ0.5H2O (1)
Compound 1 is a 3D 2-fold interpenetrating framework with
CdSO4 topology. The asymmetric unit of 1 consists of one Ni(II)
ion, one 1,3-bdc ligand, one bibp ligand, one coordinated water
molecule and half of one free water molecule. As shown in
Fig. 1a, the coordination environment around Ni1 can be described
as a slightly distorted octahedral geometry, being coordinated by
three carboxylate oxygen atoms (Ni–O 2.0335(15)–2.1595(17) Å)
from two 1,3-bdc ligands as well as one oxygen atom of a coordi-
nated water molecule (Ni–O 2.0778(17) Å) at the equatorial posi-
tions, and two nitrogen atoms (Ni–N 2.0742(19) Å and 2.122
(2) Å) from two bibp ligands at the axial positions. Each 1,3-bdc
In order to minimize the large voids from a single 3D frame-
work and stabilize the structure, two identical frameworks inter-
penetrate each other, thus giving a new 2-fold interpenetrating
framework (Fig. 2d). Due to such twofold interpenetration, the sol-
vent-accessible voids of 2 are radically reduced to be only 2.2% of
the crystal volume as calculated by PLATON [20]. Besides, a further
ligand adopts (j j
2)-( 1)-l2 coordination mode connecting two Ni
atoms (mode I, Scheme S3). Using two imidazole rings at either
end, each bibp ligand acts as a bridging ligand connecting two
adjacent Ni(II) ions (Scheme S2). Based on these connection modes,
the Ni atoms are linked by these two kinds of organic ligands,
resulting in the formation of a 3D framework (Fig. 1c).
investigation reveals that there exist the
tions between the benzene rings and the imidazole rings of differ-
p p stacking interac-
ꢀ ꢀ ꢀ
From a topological viewpoint, each Ni atom can be regarded as a
4-connected node and all organic ligands can be considered as lin-
ear linkers (Fig. 1b). Therefore, the 3D structure in 1 can be simpli-
fied as a 4-connected net with (65ꢀ8) CdSO4-type topology. The
spacious nature of the single 3D framework allows one identical
network to penetrate it, thus finally giving a 2-fold interpenetrat-
ing framework (Fig. 1d).
ent bibp ligands (center-to-center distance: 3.88 Å, Fig. S3).
3.1.3. Structure of [Co(oba)(bibp)] (4)
When oba, a longer ditopic carboxylate ligand, was used to
react with cobalt salt and bibp, a new structure of 4 was obtained.
Compound 4 is an unusual 2D ? 3D interdigitated framework
formed from 2D ? 2D threefold interpenetration motifs. The
asymmetric unit of 4 consists of one Co(II) ion, one oba ligand,
one bibp ligand and two free water molecules. As shown in
Fig. 3a, the Co1 atom is coordinated by three carboxylate oxygen
atoms (Co–O 2.001(4)–2.313(5) Å) from two oba ligands and two
nitrogen atoms (Co–N 2.041(6) and 2.080(6) Å) from two bibp
ligands, to furnish a distorted trigonal-bipyramidal geometry. The
oba ligand binds two Co(II) cations, one carboxylate group in
monodentate and the other in bidentate fashion (mode III,
3.1.2. Structures of [Ni(btec)0.5(bibp)1.5]ꢀH2O (2) and [Co
(btec)0.5(bibp)1.5]ꢀH2O (3)
When tetracarboxylate ligand btec was introduced into the
reaction system, two 2-fold interpenetrating pcu networks were
isolated. Compounds 2 and 3 are isostructural (Fig. S1), so only
the structure of 2 will be discussed in detail. In the asymmetric
unit, there are one Ni(II) ion, half of a btec ligand, one and a half
Table 1
Crystal data and structure refinements for compounds 1–4.
Compound
1
2
3
4
Empirical formula
C
32H33NiN6O5.5
C41H42NiN9O5
799.54
C41H42CoN9O5
799.76
C38H38CoN6O7
749.67
Mr (g molꢁ1
)
648.35
Crystal system
Space group
a (Å)
b (Å)
c (Å)
Monoclinic
C2/c
17.1617(2)
10.82945(14)
32.7999(5)
90
97.1975(13)
90
6047.87(14)
8
Triclinic
P 1
Triclinic
P 1
Monoclinic
P21/c
15.092(3)
23.551(4)
10.2410(19)
90
98.440(4)
90
3600.5(12)
4
ꢀ
ꢀ
9.31533(19)
9.8122(3)
22.6050(6)
82.249(2)
80.229(2)
69.035(2)
1895.23(9)
2
9.3896(2)
9.7401(3)
22.7444(18)
82.351(4)
80.247(4)
69.101(3)
1909.19(18)
2
a
(°)
b (°)
c
(°)
V (Å3)
Z
qcalcd (g cmꢁ3
)
1.424
1.372
1.401
1.219
1.391
4.001
1.383
0.535
l
(mmꢁ1
)
F (0 0 0)
range/°
Reflections collected
2712.0
9.68–142.352
41,924
838.0
9.684–142.936
20,832
836.0
9.75–142.85
20,802
1564.0
2.728–50.32
20,179
2
H
Unique data (Rint
)
5837 (0.0460)
1.157
0.0504/0.1234
0.0510/0.1239
7266 (0.0267)
1.036
0.0359/0.0973
0.0380/0.0992
7294 (0.0363)
1.036
0.0420/0.1100
0.0494/0.1151
6444 (0.1087)
0.977
0.0795/0.1866
0.1999/0.2500
GOF on F2
b
R1a/wR2 [I > 2
r
(I)]
b
R1a/wR2 (all data)
P
P
a
R1
wR2
=
||F0|-|FC||/ |F0|.
P
P
b
=
[w(F02-FC2)2]/ [w(F02)2]1/2
.

4
Y. Chen et al. / Inorganica Chimica Acta 451 (2016) 1–7
Fig. 1. For compound 1: (a) ORTEP diagram showing the coordination environment
for Ni atoms in 1. (b) Perspective (upper) and simplified (down) views of the four-
connected Ni atom. (c) View of a single 3D framework. (d) Schematic representation
of the 3D 2-fold interpenetrating framework.
Scheme S3). Meanwhile, the bibp ligand acts as a linear bridging
ligand connecting two Co atoms (Scheme S2). On the basis of these
connection modes, Co atoms are linked by oba and bibp ligands to
form a 2D (44)-sql network (Fig. 3b and c). The single 2D sheet con-
tains large windows with dimensions of 15.09 ꢂ 21.67 Å, and exhi-
bits an undulating character with a thickness of ca. 15.43 Å
(Fig. S4). The large quadrilateral grids and the corrugation of the
single sheet allow two other identical nets to penetrate it, giving
a 3-fold 2D ? 2D parallel interpenetrating layer (Fig. 3d).
Interestingly, the oba out of the layer can be regarded as a
‘tooth’, and each 2D interpenetrating layer exhibits sawtooth-like
arrangement [21], which provide enough space for the occurrence
of interdigitation. So the adjacent layers are interdigitated in a par-
allel fashion to yield an unusual 2D ? 3D interdigitated framework
Fig. 2. For compound 2: (a) ORTEP diagram showing the coordination environment
for Ni atoms in 2. (b) View of the 3D pillared double-layer framework. (c)
Perspective (upper) and simplified (down) views of the linkages of a dimetallic SBU
with six equivalent neighbors. (d) Schematic representation of the 3D 2-fold
interpenetrating framework.
interpenetrating coordination polymer. On the one hand, as a lin-
ear bidentate ligand, bibp bridges metal centers to add the dimen-
sion of the structures. On the other hand, thanks to the sufficient
length, bibp could generate large voids that may result in interpen-
etrating networks.
(Fig. 3e). In addition, there also exist the
p p stacking interactions
ꢀ ꢀ ꢀ
3.2. X-ray powder diffractions and thermal properties for compounds
1–4
between the benzene rings and the imidazole rings of different
bibp ligands (center-to-center distance: 3.66 Å, Fig. S5), which fur-
ther stabilize the network of 4.
The interpenetrating networks of compounds 1–4 indicate that
the bibp ligand could be a good candidate for the construction of
In order to check the phase purity of compounds 1–4, the X-ray
powder diffraction (PXRD) patterns were recorded at room tem-
perature. As shown in Figs. S6–S9, the peak positions of simulated

Y. Chen et al. / Inorganica Chimica Acta 451 (2016) 1–7
5
Fig. 4. Thermal gravimetric curves for 1–4.
temperature to 120 °C, assigned to the loss of free water molecules
(calcd 2.25%). The structure starts to decompose above 320 °C. For
3, the weight loss of 2.28% at temperatures below 96 °C is consis-
tent with the removal of free water molecules (calcd 2.25%). In
the range of 281–760 °C, the structure decomposes to form CoO
as the residue (obsd 9.35%, calcd 9.38%). For 4, the weight loss of
4.76% at temperatures below 170 °C is consistent with the removal
of free water molecules (calcd 4.81%). The decomposition of the
structure starts at 287 °C.
3.3. Magnetic properties
The magnetic properties of compounds 1–4 were measured in
the temperature range of 2–300 K at a direct current field of
1.0 kOe (Fig. 5 and Table 2).
For 1, the
Fig. 5a), which is slightly higher than the expected value
(1.000 cm3 K molꢁ1, 2.828
B) of one isolated spin-only Ni(II) ion
v ;
MT value at 300 K is 1.290 cm3 K molꢁ1 (3.212 lB
l
(S = 1, g = 2.0). As T is lowered,
vMT continuously decreases to a
value of 1.229 cm3 K molꢁ1 at 21.8 K, and then increases to a max-
imum value at 9.5 K (1.302 cm3 K molꢁ1). Below the temperature,
the
v
MT product decreases sharply to 0.784 cm3 K molꢁ1 at 2 K.
The magnetic behavior of 1 might be contributed to the competi-
tion between zero-field splitting effects of Ni(II) ions and a very
weak ferromagnetic coupling among distantly separated Ni(II) ions
[22].
For 2, the
Fig. 5b), which is higher than the expected value
(1.000 cm3 K molꢁ1, 2.828
B) of one isolated spin-only Ni(II) ion
(S = 1, g = 2.0). The MT value of 2 remains almost constant from
v ;
MT value at 300 K is 1.439 cm3 K molꢁ1 (3.393 lB
Fig. 3. For compound 4: (a) ORTEP diagram showing the coordination environment
for Co atoms in 4. (b) Perspective (upper) and simplified (down) views of the four-
connected Co atom. (c) View of a single 2D corrugated (4,4) layer. (d) View of the
2D ? 2D parallel 3-fold interpenetration. (e) View of the 2D ? 3D interdigitated
structure.
l
v
300 K to 60 K, and then increases on further cooling, reaching a
maximum value of 1.958 cm3 K molꢁ1 at 2.9 K. Below this temper-
ature, the
v
MT product decreases to 1.892 cm3 K molꢁ1 at 2 K.
These behaviors indicate the presence of ferromagnetic interac-
tions between the Ni(II) ions in the structures of 2. In 2, the NiꢀꢀꢀNi
distance through the relatively short btec bridge is 9.315 Å. The
long Niꢀ ꢀ ꢀNi distance exclude an efficient direct exchange between
the Ni(II) ions [1d]. Therefore, the magnetic behavior of 2 can be
explained by the magnetic exchange coupling within the binuclear
nickel clusters.
and experimental patterns are in good agreement with each other,
demonstrating the phase purity of the products. The differences in
intensity may be due to the preferred orientation of the crystalline
powder samples.
Thermal gravimetric analyses (TG) were performed on com-
pounds 1–4 to investigate their thermal stabilities (Fig. 4). For 1,
the first weight loss is 4.28% from room temperature to 260 °C,
assigned to the release of the coordinated and lattice water mole-
cules (calcd 4.17%). The second weight loss corresponding to the
release of organic ligands is observed from 288 to 708 °C. The
remaining residue corresponds to the formation of NiO (obsd
11.0%, calcd 11.52%). For 2, the first weight loss is 2.36% from room
For 3, the
Fig. 5c), which is much higher than the expected value
(1.875 cm3 K molꢁ1, 3.873
B) of one isolated spin-only Co(II) ion
v ;
MT value at 300 K is 3.079 cm3 K molꢁ1 (4.963 lB
l
(S = 3/2, g = 2.0), which can be ascribed to the strong orbital
contribution to the magnetic moment of Co(II) centers [23]. As T
is lowered,
vMT continuously decreases and reaches a minimum

6
Y. Chen et al. / Inorganica Chimica Acta 451 (2016) 1–7
Fig. 5. Thermal variation of vM and
v
MT for compounds 1 (a), 2 (b), 3 (c) and 4 (d). Inset: Plot of thermal variation of vꢁM1 for the respective compound.
(S = 3/2, g = 2.0), which can be ascribed to the strong orbital contri-
Table 2
bution to the magnetic moment of Co(II) centers [23]. As T is low-
ered,
MT continuously decreases to a value of 2.729 cm3 K molꢁ1
at 51.9 K, and then increases to a maximum of 3.291 cm3 K molꢁ1
The Curie-Weiss fitting of 1/vM for compounds 1–4.
v
Compound
T (K)
C (cm3 K molꢁ1
)
h (K)
1
2
3
4
2–300
2–300
50–300
50–300
1.201
1.323
3.107
3.289
0.753
2.567
at 30.6 K. Below the temperature,
vMT decreases sharply and
reaches 1.713 cm3 K molꢁ1 at 2 K. The magnetic behavior of 4 is
unusual and interesting, indicative of a strong antiferromagnetic
interaction admixture with a very weak ferromagnetic interaction
[25].
ꢁ17.456
ꢁ12.270
value of 2.352 cm3 K molꢁ1 at 33.9 K originating from spin-orbit
coupling, and then sharply increases to a maximum value of
3.297 cm3 K molꢁ1 at 2 K, exhibiting ferromagnetic interaction in
the Co(II) dimer [24].
4. Conclusion
Four new Ni(II)/Co(II) coordination compounds, constructed
from a long flexible N-donor ligand (bibp) with different polycar-
boxylates under hydrothermal conditions, display different inter-
For 4, the
Fig. 5d), which is much higher than the expected value
(1.875 cm3 K molꢁ1, 3.873
B) of one isolated spin-only Co(II) ion
v ;
MT value at 300 K is 3.238 cm3 K molꢁ1 (5.090 lB
l
penetrating
structures.
Compounds
1–3
are
2-fold

Y. Chen et al. / Inorganica Chimica Acta 451 (2016) 1–7
7
[5] (a) J.P. Zou, Q. Peng, Z.H. Wen, G.S. Zeng, Q.J. Xing, G.C. Guo, Cryst. Growth Des.
10 (2010) 2613;
interpenetrating 3D frameworks (topology: cds in 1 and pcu in 2 &
3). Compound 4 is a 2D ? 3D interdigitated network assembled
from 2D ? 2D 3-fold interpenetrating layers. Considering that
the combination of bibp ligand and polycarboxylates in the assem-
bly process may be a promising strategy for constructing new
interpenetrating networks, further work is in progress.
(b) Z. Yin, Q.X. Wang, M.H. Zeng, J. Am. Chem. Soc. 134 (2012) 4857;
(c) H.Y. Yang, L.K. Li, Y.L. Song, H.W. Hou, Y.T. Fan, J. Organomet. Chem. 693
(2008) 2624.
[6] (a) T. Grancha, J. Ferrando-Soria, M. Castellano, M. Julve, J. Pasan, D.
Armentano, E. Pardo, Chem. Commun. 50 (2014) 7569;
(b) F.P.A. Fabbiani, Acta Crystallogr. B 71 (2015) 247;
(c) J. Xiao, B.Y. Liu, G. Wei, X.C. Huang, Inorg. Chem. 50 (2011) 11032.
[7] (a) L. Carlucci, G. Ciani, D.M. Proserpio, Coord. Chem. Rev. 246 (2003) 247;
(b) S.R. Batten, R. Robson, Angew. Chem., Int. Ed. 37 (1998) 1460;
(c) S.R. Batten, CrystEngComm 3 (2001) 67.
Acknowledgments
[8] (a) V.A. Blatov, L. Carlucci, G. Ciani, D.M. Proserpio, CrystEngComm 6 (2004)
378;
This work was financially supported by the NSFC (21571149),
the Program for Chongqing Excellent Talents in University, the
Fundamental Research Funds for the Central Universities
(XDJK2013A027, XDJK2016C101), and the Open Foundation of
Key Laboratory of Synthetic and Natural Functional Molecule
Chemistry of Ministry of Education (338080045).
(b) I.A. Baburin, V.A. Blatov, L. Carlucci, G. Ciani, D.M. Proserpio,
CrystEngComm 10 (2008) 1822;
(c) I.A. Baburin, V.A. Blatov, L. Carlucci, G. Ciani, D.M. Proserpio, Cryst. Growth
Des. 8 (2008) 519;
(d) K.L. Huang, X. Liu, G.M. Liang, Inorg. Chim. Acta 362 (2009) 1565;
(e) E.V. Alexandrov, V.A. Blatov, A.V. Kochetkov, D.M. Proserpio,
CrystEngComm 13 (2011) 3947.
[9] (a) Y.H. Xu, Y.Q. Lan, X.L. Wang, H.Y. Zang, K.Z. Shao, Y. Liao, Z.M. Su, Solid State
Sci. 11 (2009) 635;
Appendix A. Supplementary data
(b) X. Zhu, X.G. Liu, B.L. Li, Y. Zhang, CrystEngComm 11 (2009) 997;
(c) H.Y. Zang, Y.Q. Lan, G.S. Yang, X.L. Wang, K.Z. Shao, G.J. Xu, Z.M. Su,
CrystEngComm 12 (2010) 434.
CCDC 1407248 for 1, 1407253 for 2, 1407254 for 3 and 1407252
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. These data include some additional structural
figures and tables, PXRD patterns and IR spectrum. Supplementary
data associated with this article can be found, in the online version,
at http://dx.doi.org/10.1016/j.ica.2016.07.001.
[10] L. Carlucci, G. Ciani, D.M. Proserpio, S. Rizzato, Chem. Eur. J. 8 (2002) 1519.
[11] H.Y. Chen, D.R. Xiao, J.H. He, Z.F. Li, G.J. Zhang, D.Z. Sun, R. Yuan, E.B. Wang, Q.L.
Luo, CrystEngComm 13 (2011) 4988.
[12] T.T. Fan, J.J. Li, X.L. Qu, H.L. Han, X. Li, CrystEngComm 17 (2015) 9443.
[13] C.M. Nagaraja, B. Ugale, A. Chanthapally, CrystEngComm 16 (2014) 4805.
[14] (a) W. Wang, W.Q. Kan, J. Yang, J.F. Ma, CrystEngComm 15 (2013) 3824;
(b) P. Yang, J.J. Wu, H.Y. Zhou, B.H. Ye, Cryst. Growth Des. 12 (2012) 99.
[15] O.V. Dolomanov, L.J. Bourhis, R.J. Gildea, J.A.K. Howard, H. Puschmann, J. Appl.
Crystallogr. 42 (2009) 339.
[16] (a) L. Palatinus, G. Chapuis, J. Appl. Crystallogr. 40 (2007) 786;
(b) L. Palatinus, A. van der Lee, J. Appl. Crystallogr. 41 (2008) 975;
(c) L. Palatinus, S.J. Prathapa, S. van Smaalen, J. Appl. Crystallogr. 45 (2012)
575.
References
[17] G.M. Sheldrick, Acta Crystallogr. Sect. A: Found Crystallogr. 64 (2008) 112.
[18] G.M. Sheldrick, Acta Crystallogr. C 71 (2015) 3.
[19] V.A. Blatov, A.P. Shevchenko, V.N. Serezhkin, J. Appl. Crystallogr. 33 (2000)
1193.
[1] (a) T.R. Cook, Y.R. Zheng, P.J. Stang, Chem. Rev. 113 (2013) 734;
(b) J. Yang, J.F. Ma, S.R. Batten, Chem. Commun. 48 (2012) 7899;
(c) J.P. Zhang, Y.B. Zhang, J.B. Lin, X.M. Chen, Chem. Rev. 112 (2012) 1001;
(d) D.R. Xiao, E.B. Wang, H.Y. An, Y.G. Li, Z.M. Su, C.Y. Sun, Chem. Eur. J. 12
(2006) 6528;
[20] A.L. Spek, J. Appl. Crystallogr. 36 (2003) 7.
[21] B.Q. Song, C. Qin, Y.T. Zhang, X.S. Wu, H.S. Liu, K.Z. Shao, Z.M. Su,
CrystEngComm 17 (2015) 3129.
(e) H.Y. Chen, D.R. Xiao, S.W. Yan, J.H. He, J. Yang, X. Wang, R. Yuan, E.B. Wang,
Inorg. Chim. Acta 387 (2012) 283.
[22] C.M. Liu, S. Gao, H.M. Hu, X. Jin, H.Z. Kou, Dalton Trans. (2002) 598.
[23] (a) G. Demunno, M. Julve, F. Lloret, J. Faus, A. Caneschi, Dalton Trans. (1994)
1175;
(b) Y. Chen, J. Yang, X.C. Wang, Y.C. Xu, H.L. Xu, X.S. Zeng, D.R. Xiao, RSC Adv. 6
(2016) 5729.
[24] (a) J. Souletie, P. Rabu, M. Drillon, in: Magnetism: Molecules to Materials V,
Wiley-VCH Verlag GmbH & Co. KgaA, 2005, p. 347;
[2] (a) A. Shigematsu, T. Yamada, H. Kitagawa, J. Am. Chem. Soc. 134 (2012)
13145;
(b) C. Serre, Angew. Chem., Int. Ed. 51 (2012) 6048;
(c) J.R. Li, J. Sculley, H.C. Zhou, Chem. Rev. 112 (2012) 869;
(d) Y.Y. Fu, C.X. Yang, X.P. Yan, Langmuir 28 (2012) 6794.
[3] (a) J.M. Falkowski, C. Wang, S. Liu, W.B. Lin, Angew. Chem., Int. Ed. 50 (2011)
8674;
(b) J. Yang, J.L. Liu, X. Wang, X.L. Chi, J.L. Zhang, H.Y. Zhang, D.R. Xiao, Q.L. Luo,
CrystEngComm 15 (2013) 10435.
[25] J. Tao, Y. Zhang, M.L. Tong, X.M. Chen, T. Yuen, C.L. Lin, X.Y. Huang, J. Li, Chem.
Commun. (2002) 1342.
(b) M. Yoon, R. Srirambalaji, K. Kim, Chem. Rev. 112 (2012) 1196;
(c) X.W. Dong, T. Liu, Y.Z. Hu, X.Y. Liu, C.M. Che, Chem. Commun. 49 (2013)
7681.
[4] O. Shekhah, J. Liu, R.A. Fischer, C. Woll, Chem. Soc. Rev. 40 (2011) 1081.