Synthesis, crystal structure, and magnetic properties of two-dimensional divalent metal glutarate/dipyridylamine coordination polymers, with a single crystal-to-single crystal transformation in the copper derivative

Article abstract of DOI:10.1016/j.jssc.2008.09.020

Hydrothermal reaction of divalent metal chlorides with glutaric acid and 4,4′-dipyridylamine (dpa) has afforded an isostructural family of coordination polymers with formulation [M(glu)(dpa)]_n (M=Co (1), Ni (2), Cu (3); glu=glutarate). Square p

Full text of DOI:10.1016/j.jssc.2008.09.020

ARTICLE IN PRESS
Journal of Solid State Chemistry 182 (2009) 8–17
Contents lists available at ScienceDirect
Journal of Solid State Chemistry
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Synthesis, crystal structure, and magnetic properties of two-dimensional
divalent metal glutarate/dipyridylamine coordination polymers, with a single
crystal-to-single crystal transformation in the copper derivative
Ã
Matthew R. Montneya, Ronald M. Supkowski b, Richard J. Staples a, Robert L. LaDuca a,
a Lyman Briggs College and Department of Chemistry, Michigan State University, East Lansing, MI 48825, USA
b Department of Chemistry and Physics, King’s College, Wilkes-Barre, PA 18711, USA
a r t i c l e i n f o
a b s t r a c t
Hydrothermal reaction of divalent metal chlorides with glutaric acid and 4,40-dipyridylamine (dpa) has
afforded an isostructural family of coordination polymers with formulation [M(glu)(dpa)]n (M ¼ Co (1),
Ni (2), Cu (3); glu ¼ glutarate). Square pyramidal coordination is seen in 1–3, with semi-ligation of a
sixth donor to produce a ‘‘5+1’’ extended coordination sphere. Neighboring metal atoms are linked into
1D [M(glu)]n neutral chains through chelating/monodentate bridging glutarate moieties with a syn–anti
binding mode, and semi-chelation of the pendant carboxylate oxygen. These chains further connect into
2D layers through dipodal dpa ligands. Neighboring layers stack into the pseudo 3D crystal structure of
1–3 through supramolecular hydrogen bonding between dpa amine units and the semi-chelated
glutarate oxygen atoms. The variable temperature magnetic behavior of 1–3 was explored and modeled
as infinite 1D Heisenberg chains. Notably, complex 3 undergoes a thermally induced single crystal-to-
single crystal transformation between centric and acentric space groups, with a conformationally
disordered unilayer structure at 293 K and an ordered bilayer structure at 173 K. All materials were
further characterized via infrared spectroscopy and elemental and thermogravimetric analyses.
& 2008 Elsevier Inc. All rights reserved.
Article history:
Received 22 May 2008
Received in revised form
8 September 2008
Accepted 21 September 2008
Available online 11 October 2008
Keywords:
Coordination polymer
Crystal structure
Dicarboxylate
SCSC
Antiferromagnetism
Ferromagnetism
1. Introduction
[Zn4O(isophthalate)3(4,40-bpy)] has potential use as
a blue
luminescent material [8], and the interpenetrated 3D material
[Zn(terephthalate)(4,40-bpy)0.5] can chromatographically separate
branched and linear hydrocarbons [9].
Compared with benzenedicarboxylate MOFs, organodiimine-
scaffolded coordination polymers based on longer aliphatic
Over the past decade intense investigation has focused on
dicarboxylate metal-organic frameworks (MOFs) due to their
capabilities in gas storage [1], shape-selective separations [2], ion-
exchange [3], catalysis [4], non-linear optics [5], luminescence [6],
and magnetism [7]. In these phases dianionic dicarboxylates act
as tethering ligands to connect neighboring metal ions into a
diverse range of structural motifs, hinged on the disposition of
donor atoms and the ability of these ligands to adopt a wide
variety of binding modes and to provide loci for structure-
directing supramolecular hydrogen bonding interactions.
They also allow the charge balance necessary to permit self-
assembly of neutral MOFs without the incorporation of smaller
anions that could inhibit formation of void spaces. The level of
structural complexity in dicarboxylate MOFs can be enhanced
through the introduction of neutral nitrogen-based tethering
ligands such as 4,40-bipyridine (4,40-bpy), which can connect
metal cations through its distal pyridyl nitrogen donor atoms into
structurally intriguing solids with interesting physicochemical
properties [8–10]. For example, the 2D layered phase
a,o-dicarboxylates have received less attention [10–14]. While
the structural rigidity of benzenedicarboxylate subunits is
advantageous for the construction of porous materials, flexible
aliphatic dicarboxylates can provoke novel structural motifs due
to their ability to access numerous energetically similar con-
formations. For instance, a few divalent metal adipate (adp)
coordination polymers incorporating 4,40-bpy or bpe have been
reported, in all cases manifesting interpenetrated 3D networks
with the well-known a-Po topology [10–12].
For some time we have been interested in the synthesis and
characterization of coordination polymers containing the organo-
diimine 4,40-dipyridylamine (dpa). Unlike 4,40-bpy, dpa possesses
a kinked disposition of its terminal nitrogen donor atoms as well
as a hydrogen bonding locus at its center, allowing it to promote
the formation of novel structural patterns via supramolecular as
well as covalent interactions.
Combination of dpa and
a,o-dicarboxylic acids with appro-
Ã
priate metal precursors under hydrothermal conditions has
resulted in the construction of extended solids with interesting
Corresponding author.
E-mail address: laduca@msu.edu (R.L. LaDuca).
0022-4596/$ - see front matter & 2008 Elsevier Inc. All rights reserved.
doi:10.1016/j.jssc.2008.09.020

ARTICLE IN PRESS
M.R. Montney et al. / Journal of Solid State Chemistry 182 (2009) 8–17
9
yield based on Co) were isolated after washing with distilled
water, ethanol, and acetone and drying in air. Crystals of 1 display
pleochroism, appearing brown, orange, or violet depending on
their orientation with respect to a bright light source. Anal. Calc.
for C15H15CoN3O4 1: C, 50.01; H, 4.20; N, 11.67%. Found: C, 49.50;
H, 3.93; N, 11.43%. IR (KBr, cmꢀ1): 3450 w br (NH), 3292 w, 3074 w,
2971 m, 2925 s, 2858 m (CH), 1638 m, 1596 s (CO2 asym), 1561 s,
1535 s, 1492 m, 1462 m, 1443 m, 1404 m, 1359 m (CO2 sym),
1332 m, 1297 w, 1252 w, 1211 m, 1150 w, 1070 w, 1064 w, 1021 m,
910 w, 857 m, 819 m, 735 w, 677 w, 650 m, 620 w, 589 w, 532 m.
Scheme 1.
and diverse structural motifs [15–17]. For instance, [Co(succina-
te)(dpa)2]n displays homochiral 1D helices linked together via
2.3. Preparation of [Ni(glu)(dpa)]n (2)
.
dpa-mediated hydrogen bonding. {[Cu(succinate)(dpa)] 0.5H2O}n
.
The procedure for 1 above was followed, using NiCl2 6H2O
adopts a rarely seen two-fold interpenetrated CdSO4 lattice
(658 topology), while {[Ni(dpa)2(succinate)0.5]Cl}n manifested a
unique uniform 5-connected self-penetrated 610 topology (rld-z)
(88 mg, 0.37 mmol), dpa (127 mg, 0.73 mmol) and glutaric acid
(49 mg, 0.37 mmol). For optimized yields, the best reaction
temperature was determined to be 150 1C. Green blocks of 2
(72 mg, 54% yield based on Ni) were isolated after washing with
distilled water, ethanol, and acetone and drying in air. Calc. for
network [15]. The longer chain a,o-dicarboxylate adipate allowed
formation of [Co(adipate)(dpa)]n, a material exhibiting a rather
common two-fold interpenetrated primitive cubic 6-connected
lattice. However, use of a divalent nickel precursor resulted in the
crystallization of [Ni(adipate)(dpa)(H2O)]n, which is the first
example of a triply interpenetrated PtS framework (binodal 4284
topology). Herein we report the first dpa-containing glutarate
(glu, 1,5-pentanedicarboxylate, Scheme 1) coordination polymers
with the hydrothermal synthesis and structural characterization
of three related complexes, [M(glu)(dpa)]n (M ¼ Co, 1; M ¼ Ni, 2;
M ¼ Cu, 3). Thermal and magnetic properties of these materials
C
15H15NiN3O4 2: C, 50.04; H, 4.20; N, 11.67%; Found: C, 49.84; H,
3.97; N, 11.55%. IR (KBr, cmꢀ1): 3450 w br (NH), 3292 w, 3074 w,
2971 m, 2921 s, 2848 m, 1638 m, 1577 s, 1557 s, 1538 s (CO2 asym),
1508 m, 1492 m, 1466 m, 1443 m, 1404 m, 1359 m (CO2 sym),
1332 m, 1295 w, 1252 w, 1213 m, 1152 w, 1070 w, 1064 w,
1021 m, 910 w, 861 m, 826 m, 734 w, 679 w, 658 m, 646 m, 631 w,
596 m, 543 m.
2.4. Preparation of [Cu(glu)(dpa)]n (3)
are also discussed, along with
a curious thermally-induced
ordered to disordered single crystal-to-single crystal (SCSC)
transition in the case of compound 3.
.
The procedure for 1 above was followed, using CuCl2 2H2O
(63 mg, 0.37 mmol), dpa (127 mg, 0.73 mmol), and glutaric acid
(49 mg, 0.37 mmol). Blue blocks of 3 (59 mg, 44% yield based on
Cu) were isolated after washing with distilled water, ethanol, and
acetone and drying in air. Calc. for C15H15CuN3O4 3: C, 49.38; H,
4.14; N, 11.52%. Found: C, 49.08; H, 3.99; N, 11.53%. IR (KBr, cmꢀ1):
2903 w br, 1632 w, 1580 s, 1542 s (CO2 asym), 1523 s, 1487 s,
1455 m, 1440 m, 1416 m, 1388 m, 1351 s (CO2 sym), 1327 m,
1299 m, 1274 w, 1251 w, 1207 s, 1160 w, 1067 w, 1057 m, 1042 w,
1024 s, 907 m, 857 w, 840 w, 819 s, 799 m, 730 w, 679 w, 663 w.
2. Experimental section
2.1. General considerations
.
.
.
CoCl2 6H2O, NiCl2 6H2O, CuCl2 2H2O (Fisher), and glutaric
acid (Aldrich) were obtained commercially. 4,40-dipyridylamine
(dpa) was prepared via a published procedure [18]. Water was
deionized above 3 M
O in-house. Thermogravimetric analysis was
performed on TA Instruments TGA 2050 thermogravimetric
analyzer with a heating rate of 10 1C/min up to 900 1C under
flowing N2. Elemental Analysis was carried out using a Perki-
n–Elmer 2400 Series II CHNS/O Analyzer. IR spectra were recorded
on a Mattson Galaxy FTIR Series 3000 using KBr pellets. Powder
X-ray diffraction on ground samples of 1–3 for phase purity
3. X-ray crystallography
A
brown block of
1
(with dimensions 0.78 mm ꢁ 0.56
mm ꢁ 0.48 mm), a green block of 2 (0.42 mm ꢁ 0.20 mm ꢁ 0.18
mm), and a blue block of 3 (0.24 mm ꢁ 0.10 mm ꢁ 0.10 mm) were
subjected to single crystal X-ray diffraction using a Bruker-AXS
SMART 1k CCD instrument at 173 K. The X-ray diffraction
experiment for the same single crystal of 3 was repeated at
verification were obtained via
Y–2Y scans performed on a Rigaku
Rotaflex instrument. Variable temperature magnetic susceptibility
data (2–300 K) was collected on a Quantum Design MPMS SQUID
magnetometer at an applied field of 0.1 T. After each temperature
change the sample was kept at the new temperature for 5 min
before magnetization measurement to ensure thermal equili-
brium. The susceptibility data was corrected for diamagnetism
using Pascal’s constants [19]. Differential scanning calorimetry on
a sample of crystalline 3 was carried out using a TA Instruments
DSC 2010 instrument.
293 K. Reflection data was acquired using graphite-monochromated
˚
MoKa radiation (l ¼ 0.71073 A). The data was integrated via
SAINT [20]. Lorentz and polarization effect and empirical absorp-
tion corrections were applied with SADABS [21]. The structures
were solved using direct methods and refined on F2 using
SHELXTL [22]. All non-hydrogen atoms were refined anisotropi-
cally. Hydrogen atoms bound to carbon atoms were placed in
calculated positions and refined isotropically with a riding model.
The hydrogen atoms bound to the central nitrogen of the
dpa moieties in 1–3 were found via Fourier difference maps, then
restrained at fixed positions and refined isotropically. Attempts
to refine the crystal structure of 3 using the low temperature
reflection data in the higher symmetry centrosymmetric space
group Pbcm with a disordered glutarate conformation model
resulted in unacceptably high wR2 values (ꢂ0.52), with 355
systematic absence violations. Acceptable solution was possible
2.2. Preparation of [Co(glu)(dpa)]n (1)
.
CoCl2 6H2O (88 mg, 0.37 mmol), dpa (127 mg, 0.73 mmol), and
glutaric acid (49 mg, 0.37 mmol) were placed into 10 mL distilled
H2O in a 23 mL Teflon-lined Parr acid digestion bomb. The bomb
was sealed and heated at 120 1C for 48 h, whereupon it was cooled
slowly to 25 1C. Large single crystalline blocks of 1 (110 mg, 82%

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M.R. Montney et al. / Journal of Solid State Chemistry 182 (2009) 8–17
Table 1
tion of the appropriate metal chloride, 4,40-dipyridylamine, and
Crystal and structure refinement data for 1–3
glutaric acid. The infrared spectra of 1–3 were fully consistent
with their formulations. Features corresponding to pyridyl ring
puckering mechanisms were evident in the region between 800
and 600 cmꢀ1. Sharp, medium intensity bands in the range of
ꢂ1600–ꢂ1200 cmꢀ1 were ascribed to stretching modes of the
pyridyl rings of the dpa moieties [23]. Asymmetric and symmetric
C–O stretching modes of the glutarate carboxylate moieties were
evidenced by very strong, slightly broadened bands at ꢂ1580 and
ꢂ1350 cmꢀ1. The multiplicity of peaks in this region corroborates
the presence of different binding modes present at each glutarate
carboxylate terminus. Bands in the region of ꢂ3400 cmꢀ1 in all
cases represent N–H stretching modes within the dpa ligands;
their broadness is indicative of hydrogen bonding to carboxylate
oxygen atoms (vide infra).
Data
1
2
Empirical formula
Formula weight
C15H15CoN3O4
360.23
C15H15N3NiO4
360.01
Collection T (K)
173(2)
173(2)
˚
0.71073
Orthorhombic
Pbcn
0.71073
Orthorhombic
Pbcn
l
(A)
Crystal system
Space group
˚
a (A)
15.3995(12)
8.2673(9)
23.476(3)
2988.8(6)
8
15.412(3)
8.2158(17)
23.273(5)
2946.8(11)
8
˚
b (A)
˚
c (A)
3
˚
V (A )
Z
Dcalc (g cmꢀ3
(mmꢀ1
)
1.601
1.623
m
)
1.173
1.341
Min/max trans.
0.868
0.821
hkl ranges
ꢀ20php20
ꢀ11pkp11
ꢀ31plp31
32906
ꢀ20php19
ꢀ10pkp10
ꢀ30plp31
33456
4.2. Structural description of [M(glu)(dpa)]n (M ¼ Co, 1; M ¼ Ni, 2)
Total reflections
Unique reflections
R (int)
3649
3649
As revealed by single-crystal X-ray diffraction, compounds 1
and 2 are isomorphous and crystallize in the centrosymmetric
orthorhombic space group Pbcn with an asymmetric unit consist-
ing of one divalent metal ion, one glu dianion and one ligated dpa
molecule (Fig. 1, shown for 1). The metal atoms display a distorted
0.0193
0.0653
Parameters/restraints
R1 (all data)
212/0
211/1
0.0268
0.0611
R1 (I42
wR2 (all data)
wR2 (I42 (I))
s(I))
0.0240
0.0394
0.0609
0.0880
s
0.0592
0.0795
square pyramidal [MN2O3] coordination geometry (
t ¼ 0.223 for
Max/min residual (eꢀ/A )
0.376/ꢀ0.257
1.058
0.489/ꢀ0.551
1.063
3
˚
1, 0.224 for 2) [24] with trans nitrogen donors from two different
dpa ligands anchoring the basal plane. A glu dianion in a 1,5-
chelating binding mode fulfills the apical coordination site and
one position in the basal plane. The glu ligands in these complexes
adopt gauche–gauche conformations with four C-atom torsion
angles of 62.61 and 65.91 for 1 and 62.21 and 65.41 for 2. The
fourth and final basal plane coordination site in each case is
occupied by an oxygen atom from a second glu ligand. Bond
lengths and angles (Table 1) are consistent with divalent cobalt
and nickel in a distorted square pyramidal coordination environ-
ment, with subtle differences consistent with well-established
ionic radius trends [25].
G.O.F.
Data
3 (low temperature)
3 (high temperature)
Empirical formula
Formula weight
C30H30Cu2N6O8
729.68
C15H15CuN3O4
364.84
Collection T (K)
173(2)
293(2)
˚
0.71073
Orthorhombic
Pca21
0.71073
Orthorhombic
Pbcn
l
(A)
Crystal system
Space group
˚
a (A)
8.8730(10)
14.9974(16)
22.743(3)
3026.5(6)
4
15.0653(17)
8.9015(10)
22.769(3)
3053.4(6)
8
˚
b (A)
˚
c (A)
3
˚
V (A )
Z
Adjacent metal ions are conjoined into zigzag 1D [M(glu)]n
chains parallel to the b crystal direction (Fig. 2) through bridging
glu carboxylate termini in a syn-anti binding mode, in which the
basal plane of one square pyramidal coordination sphere is linked
Dcalc (g cmꢀ3
)
1.601
1.587
m
(mmꢀ1
)
1.467
1.454
Min/max trans.
0.8299
0.8738
Hkl ranges
ꢀ11php11,
ꢀ19pkp19,
ꢀ29plp29
31 226
ꢀ19php19,
ꢀ11pkp11,
ꢀ30plp29
31 151
. . .
to the apical position of another. The M
M distances along the
˚
chain motifs in 1 and 2 measure 4.294 and 4.264 A, respectively.
Covalent connectivity within the [M(glu)]n chains is supplemen-
ted by semi-ligation [26] on the part of one of the oxygen donor
atoms involved in the 1,5-chelating binding mode of the glu
ligands. This oxygen donor atom is bound at the apical coordina-
tion site of one metal ion, and donates electron density towards
the vacant coordination site of another metal ion. Thus, a 1D
Total reflections
Unique reflections
R (int)
6 970
3 624
0.0292
0.0347
Parameters/restraints
R1 (all data)
422/3
238/1
0.0260
0.0424
R1 (I42
wR2 (all data)
wR2 (I42 (I))
s(I))
0.0225
0.0295
0.0556
0.0773
s
0.0539
0.0719
Max/min residual (eꢀ/A )
0.279/ꢀ0.258
1.040
0.329/ꢀ0.369
1.046
3
˚
. . .
. . .
repeating [M
O–M
O–]n chain within the larger [M(glu)]n
. . .
G.O.F.
chain unit can be invoked. The semi-ligating M
O distances in
1 and 2 are 2.432 and 2.417 A, respectively, causing respective
. . .
˚
aR1
¼
S
||Fo|–|Fc||/
S
|Fo|. bwR2 ¼ { [w(Fo2–Fc2)2]/ [wFo2]2}1/2
S S .
M
O–M angles of 144.41 and 145.21.
Juxtaposed [M(glu)]n chains in 1 and 2 are linked into (4,4)
rectangular grid ruffled 2D [M(glu)(dpa)]n layer parallels to the bc
. . .
only in Pca21 with racemic twinning taken into account.
Conversely, the crystal structure of 3 could not be acceptably
solved in an acentric orthorhombic space group using the high
temperature reflection data. Relevant crystallographic data for 1,
2, and 3 (at both 173 and 293 K) are listed in Table 1.
crystal plane by exobidentate dpa ligands (Fig. 3). The M
M
contact distances through the bridging dpa ligands are 11.806 (1)
˚
and 11.701 A (2), with an inter-ring torsion within the dpa ligands
of 28.71 (1) and 28.11 (2). The [M(glu)(dpa)]n single layers in 1 and
2
contrast with those in the similar manganese complex
[Mn(glu)(4,40-bpy)]n [11]. In this latter material, [Mn2(glu)2]n
. . .
4. Results and discussion
double chains, which lack any sort of M–O
M interaction, are
4.1. Synthesis and spectral characterization
linked into a thick 2D slab by the dipyridyl tethers.
Neighboring [M(glu)(dpa)]n layers are organized into pseudo
three-dimensional structures by hydrogen bonding donation
between the dpa central amine units projecting above and below
The coordination polymers 1–3 were prepared as single phase
crystalline products under hydrothermal conditions via combina-

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M.R. Montney et al. / Journal of Solid State Chemistry 182 (2009) 8–17
11
Fig. 1. Coordination environment of 1. Thermal ellipsoids are shown at 50% probability with partial atom numbering scheme. Hydrogen atoms are represented as sticks. The
coordination environment of 2 is very similar.
Fig. 2. A [Co(glu)]n chain in 1, with semi-ligating interactions shown as dashed lines. The semi-chelating oxygen atom is covalently bound at the apical site of the square
pyramidal coordination environment.
each layer, and semi-chelating carboxylate oxygen atoms belong-
ing to glu ligands in two other layers (Fig. S1). To facilitate this
supramolecular interaction, the individual layers are arranged in
an offset ABA stacking pattern. Geometrical parameters for the
interlayer hydrogen bonding patterns in 1 and 2 are listed in
Table 2. Considering the nitrogen atoms at the dpa ligands’ central
nitrogen atoms as three-connected nodes, and the metal atoms as
five-connected nodes, the overall supramolecular structures
of 1 and 2 can be visualized as a (3,5)-connected 3D network
with an unprecedented binodal (4.62)(4.65.84) topology (Fig. 4), as
analyzed via TOPOS software [27].
ments and binding modes of glu and dpa ligands to those seen
in 1 and 2. Nevertheless there are subtle variations in bond
lengths and angles about the copper atoms (Table 4). Here, the glu
dianion bound to Cu1 adopts a gauche–anti conformation (torsion
angles ¼ 66.1/153.31), while that bound to Cu2 rests in
a
gauche–gauche conformation (torsion angles ¼ 66.3/62.41). No
crystallographic disorder is evident in the glu ligands in 3 at
173 K; attempts to model the structure in a higher symmetry
centrosymmetric space group with one copper atom, one dpa
ligand, and one disordered glu ligand failed.
Adjacent Cu1 atoms are linked through the gauch–anti
conformation glu ligands to form [Cu(glu)]n 1D chains (chain-A,
. . .
˚
Cu distance of 4.694 A. Similarly, neighboring
Fig. 6a) with a Cu
4.3. Structural description and single crystal-to-single crystal
Cu2 atoms are conjoined via gauche–gauche conformation glu
transformation of [Cu(glu)(dpa)]n (3)
ligands to form crystallographically distinct [Cu(glu)]n 1D chains
˚
. . .
(chain-B, Fig. 6b) with a Cu
Cu distance over 0.1 A closer, at
˚
As done for crystals of 1 and 2, an X-ray diffraction experiment
was performed at 173 K on a single crystal of compound 3.
Dissimilar to 1 and 2, the complex crystallized in the acentric
orthorhombic space group Pca21, with an asymmetric unit
consisting of two divalent copper atoms, two glutarate dianions,
and two dpa moieties (Figs. 5a and b). Both Cu1 and Cu2 possess
distorted square pyramidal [MN2O3] coordination geometry
4.589 A. The varying glu conformations instill different twists
of neighboring copper square pyramidal coordination spheres
. . .
(291 in chain-A, 43 1 in chain-B). Cu
. . .
O semi-ligation within both
. . .
chain-A and chain-B provides [Cu
O–Cu
O–]n chain patterns,
. . .
˚
with Cu
chain-B, respectively.
O distances of 2.778 and 2.600 A within chain-A and
Chain-A 1D motifs connect into a 2D [Cu(glu)(dpa)]n layered
. . .
(
t
¼ 0.273 and 0.261, respectively) with very similar arrange-
motif (layer-A) through tethering dpa ligands, with a Cu
Cu

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M.R. Montney et al. / Journal of Solid State Chemistry 182 (2009) 8–17
Fig. 3. A single [Co(glu)(dpa)]n rectangular grid layer in 1, viewed down the a crystal direction.
Table 2
At 293 K, the same crystal of 3 gave single-crystal X-ray
diffraction data that could only be acceptably solved in the
centrosymmetric orthorhombic space group Pbcn. The asym-
metric unit consists of one divalent copper ion, one glu dianion
and one ligated dpa molecule (Fig. 8). Similar to 1 and 2, the
copper atom displays a distorted square pyramidal [MN2O3]
˚
Selected bond distance (A) and angle (1) data for 1 and 2
Co1–O2
2.0116(10)
2.0760(10)
2.1101(10)
2.1417(11)
2.1423(11)
1.2570(15)
1.2750(15)
1.2698(16)
1.2404(16)
106.86(4)
161.05(4)
91.83(3)
Ni1–O4
2.0049(18)
2.0488(17)
2.0711(18)
2.084(2)
2.086(2)
1.275(3)
1.256(3)
1.248(3)
1.270(3)
106.43(7)
161.35(7)
91.89(7)
93.92(8)
89.00(7)
89.72(8)
88.33(8)
94.87(7)
86.67(8)
174.79(8)
Co1–O3
Ni1–O1
Co1–O1#1
Ni1–O2#4
Co1–N2#2
Ni1–N2#5
Co1–N1
Ni1–N1
coordination geometry (
two different dpa ligands anchoring the basal plane. The apical
t ¼ 0.26) with trans nitrogen donors from
O1–C11
O1–C11
O3–C11
O2–C11
bond length, to a glu carboxylate oxygen atom is elongated by
O2–C15
O3–C15
9
˚
O4–C15
O4–C15
ꢂ0.2 A due to the Jahn–Teller active d electronic configuration.
O2–Co1–O3
O2–Co1–O1#1
O3–Co1–O1#1
O2–Co1–N2#2
O3–Co1–N2#2
O1#1–Co1–N2#2
O2–Co1–N1
O3–Co1–N1
O1#1–Co1–N1
N2#2–Co1–N1
O4–Ni1–O1
O4–Ni1–O2#4
O1–Ni1–O2#4
O4–Ni1–N2#5
O1–Ni1–N2#5
O2#4–Ni1–N2#5
O4–Ni1–N1
O1–Ni1–N1
O2#4–Ni1–N1
N2#5–Ni1–N1
Bond lengths and angles (Table 4) are consistent with divalent
copper in a distorted square pyramidal coordination environment.
The flexible glu ligands in 1 are disordered equally over two sets of
positions; one set represents a gauche–gauche conformation with
C–C–C–C torsion angles of 68.0/72.01, while the other set marks a
contrasting gauche–anti conformation (64.7/151.11 four-atom
torsion angles). The terminal carbon atoms within the glu chain
are common to both disordered conformations.
94.07(4)
89.35(4)
89.11(4)
88.28(4)
94.76(4)
87.07(4)
174.47(4)
Adjacent copper ions are conjoined into zigzag 1D [Cu(glu)]n
chains virtually identical to those in 1 and 2 by bridging glu
carboxylate termini in a syn–anti binding mode, in which the basal
plane of one square pyramidal coordination sphere is linked to the
Symmetry transformations to generate equivalent atoms: (#1) ꢀx+3/2, y+1/2, z;
(#2) ꢀx+3/2, ꢀy+1/2, z ꢀ1/2; (#3) ꢀx+3/2, yꢀ1/2, z; (#4) ꢀxꢀ1/2, yꢀ1/2, z; (#5)
ꢀx+1/2, ꢀy+1/2, z+1/2.
. . .
apical position of another. The Cu
Cu distance along the chain
˚
˚
through-diimine distance of 11.477 A. In layer-A the inter-ring
motif in the high temperature form of 3 measures 4.653 A.
Covalent connectivity within the [Cu(glu)]n chains is supplemen-
ted by semi-ligation on the part of one of the oxygen donor atoms
involved in the 1,5-chelating binding mode of the glu ligands. This
oxygen donor atom is bound at the apical coordination site of one
copper ion, and donates electron density towards the vacant
torsion angle within the dpa ligands subtends 31.11. In turn, chain-B
1D patterns link into similar 2D [Cu(glu)(dpa)]n units (layer-B),
˚
. . .
with a shorter Cu
Cu through-dpa distance of 11.420 A fostered
by the inter-ring torsion angle of 32.21. A similar trend, where less
acute inter-ring torsion angles result in a shorter through-dpa
metal–metal tethering distance, has been observed in other dpa-
based aliphatic dicarboxylate coordination polymers [15]. Crystal-
lographically distinct layer-A and layer-B motifs then stack in an
offset alternating pattern via hydrogen bonding mechanisms
(Table 3) mediated by the central amine units of the dpa ligands
(Fig. 7).
. . .
coordination site of another copper ion. The semi-ligating Cu
O
˚
. . .
distance is 2.684 A, causing a Cu
O–Cu angle of 139.4 1.
As in 1 and 2, dipodal dpa ligands link the [Cu(glu)]n chains
into (4,4) rectangular grid ruffled 2D [Cu(glu)(dpa)]n layers. The
. . .
Cu
Cu contact distance through the bridging dpa ligands is
˚
11.472 A, with an inter-ring torsion within the dpa ligands of 31.71.

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13
Fig. 4. Schematic perspective of the unprecedented (3,5)-connected supramolecular binodal topology in 1.
The structure of 3 contrasts markedly with that observed with
that of its rigid-rod analog [Cu2(glu)2(4,40-bpy)]n, which contains
2D [Cu2(glu)2]n layers strutted by 4,40-bpy ligands into a rare 3D
rob topology [28]. Neighboring crystallographically identical
[Cu(glu)(dpa)]n layers in the high temperature polymorph of 3
are organized into the pseudo 3D structure, stacking in an ABAB
repeat pattern through similar hydrogen bonding patterns as seen
in the Co and Ni analogues (Table 3).
the negative sign of the exchange parameter J corroborating the
likelihood of intra-chain antiferromagnetic coupling within 2.
"
!
#
ꢀ
ꢁ
Ng2
b
2SðS þ 1Þ
3k
1 þ u
1 ꢀ u
wmT ¼
þ TIPðTÞ
(1)
where u ¼ cothð2JSðS þ 1Þ=kTÞ ꢀ ðkT=2JSðS þ 1ÞÞ.
A plot of the mT product vs T for the copper derivative 3
portrays smooth decline between 300 and 10 K with
w
a
a
Thus, the low temperature and high temperature forms of 3
can be considered polymorphs that can be transformed through a
SCSC process. Most SCSC transformations in coordination poly-
mers involve the absorption or desorption of guest molecules [29],
and in some rare cases the rearrangement of covalent bonds [30].
The thermally induced SCSC transformation in 3 is not as
dramatic, instead more closely mirroring SCSC transformations
in organic systems occurring by conformational readjustments
[31]. Nevertheless the conformational changes in the flexible glu
ligand with coordination polymer 3 provide a mechanism to
toggle between acentric and centrosymmetric crystal forms.
precipitous drop at lower temperatures, hinting towards anti-
ferromagnetic coupling between neighboring copper atoms. As for
2, the variable temperature magnetic data were fit to Eq. (1), but
with S ¼ 1/2. Best fit parameters for 3 (Fig. 8) were: g ¼ 2.110(5),
J ¼ –0.33(1) cm–1
,
and TIP ¼ 1.02(1) ꢁ 10–3 cm3 mol–1 with
R ¼ 1.4 ꢁ10–4. Thus both 2 and 3 appear to exhibit antiferromag-
. . .
. . .
O–M
netic superexchange through their respective 1D [M
O–]n chain motifs.
A plot of the wmT product vs T for the cobalt derivative 1 shows
a smooth decrease from 300–15 K, below which point it increases
to 4.0 cm3 Kmol–1 at 5.5 K, only to decrease again at low
temperatures. Magnetic treatment of d7 divalent cobalt systems
is complicated by both zero-field splitting and unquenched orbital
angular momentum. Therefore, the data was fit to a phenomen-
ological expression by Rueff (Eq. (2)) [33], which takes into
account both competing single ion effects (D) and magnetic
superexchange (J), with C being equivalent to the Curie constant of
the material:
4.4. Magnetic properties of 1–3
Variable temperature magnetic susceptibility measurements
were undertaken to investigate the level of spin communication
. . .
. . .
through the [M
O–M
O–]n chain patterns within the
mT
[M(glu)(dpa)]n coordination polymer layers. A plot of the
w
product vs T for the nickel derivative 2 reveals a slow descending
curve between 300 and ꢂ30 K with a sharper decrease thereafter,
potentially indicative of weak antiferromagnetic coupling
between neighboring nickel atoms. The data were fit to the
expression of Fisher (Eq. (1)) [32] for a 1D Heisenberg chain of
w
mT ¼ A expðꢀD=kTÞ þ B expðJ=kTÞ
(2)
where A þ B ¼ C ¼ ð5Ng2
b
2=4kÞ.
Fitting the variable temperature susceptibility data to Eq. (2)
resulted in best-fit parameters (Fig. 9) of C ¼ 2.36(3) (giving
coupled spins modified by the inclusion of
a
temperature
g ¼ 2.24), D ¼ 30(1) cm–1
,
J ¼ 14(1) cm–1 with R ¼ 3.0 ꢁ10ꢀ3
.
independent paramagnetic term (TIP), with S ¼ 1 and all other
variables having their usual magnetochemical meanings. Best
fit parameters for 2 as obtained by non-linear regression were
(Fig. 7): g ¼ 2.117(4), J ¼ –0.28(1) cm–1, and TIP ¼ 2.9(3) ꢁ 10–5
Thus, in contrast to the antiferromagnetic tendencies seen in 2
and 3, the predominant magnetic superexchange pathway is
ferromagnetic. This divergent behavior is plausibly ascribed to the
overlap of different magnetic orbital sets (‘‘eg’’ only in 2 and 3,
both ‘‘t2g’’ and ‘‘eg’’ in 1), as reported for other dual-ligand
cm3 mol–1 with R ¼ {
S[(
w
mT)obs–(
w
mT)calc]2}1/2 ¼ 3.3 ꢁ10–4, with

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M.R. Montney et al. / Journal of Solid State Chemistry 182 (2009) 8–17
Fig. 5. (a, b) Coordination environments around Cu1 and Cu2 in the low temperature polymorph of 3. (c) The unique coordination environment in the high temperature
polymorph of 3, showing the two positions of the disordered glutarate ligand. Thermal ellipsoids are shown at 50% probability.
coordination polymer systems [14,34]. An examination of the low
4.5. Thermogravimetric analysis
temperature magnetic data for 1 (Fig. 10) indicates a sharp
All new phases were subjected to thermogravimetric analysis
to probe their thermal stabilities. Compound 1 remained stable
until ꢂ320 1C, whereupon removal of the organic components
occurred. The remaining material at 900 1C, 22.8% of the original
mass, corresponds roughly to the deposition of CoO (20.8% calc’d).
Compound 2 exhibited no mass loss until ꢂ275 1C, at which point
decrease in the wmT value below 5.5 K, indicative of either long-
range weak antiferromagnetic interaction through the dpa
ligands, or more likely, anisotropy-driven spin canting with
misalignment of neighboring spins from an idealized ferromag-
netic ground state. The data below 5.5 K could not be acceptably
fit with Eq. (2).

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M.R. Montney et al. / Journal of Solid State Chemistry 182 (2009) 8–17
15
Fig. 6. (a) [Cu(glu)]n chain-A motif in the low temperature polymorph of 3. (b) [Cu(glu)]n chain-B motif in the low temperature polymorph of 3. (c) Unique [Cu(glu)]n chain
motif in the low temperature polymorph of 3. Semi-ligating interactions are shown as dashed lines.
Table 3
˚
Hydrogen bonding distance (A) and angle (1) data for 1–3
. . .
. . .
. . .
d(D A)
D–H
A
d(H
A)
+DHA
Symmetry transformation for A
1
. . .
. . .
N3–H3N
N3–H3N
O4
O3
1.926(18)
1.879(19)
164.0(16)
162(3)
2.7290(16)
2.722(3)
ꢀx+2, ꢀy+1, ꢀz+1
ꢀx+1, ꢀy+1, ꢀz+1
2
3 (low temp.)
. . .
N2–H2N
N5–H5N
O2
O5
1.934(18)
1.929(18)
163(2)
162(2)
2.755(2)
2.735(2)
x+1, y, z
. . .
x ꢀ 1, y, z
3 (high temp.)
. . .
N2–H2N
O2
1.924(17)
164(2)
2.751(3)
ꢀx+2, ꢀy+1, ꢀz+1
the organic ligands are expelled. The mass remnant of 31.0% at
ꢂ440 1C is consistent with the production of NiCO3 (33.0% calc’d);
decarboxylation between ꢂ440 1C and ꢂ700 1C resulted in likely
deposition of NiO (20.3% observed remaining mass, 20.8% calc’d).
Compound 3 began to expel its organic components at ꢂ250 1C,
with a sharp mass loss noted immediately thereafter. A final mass

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M.R. Montney et al. / Journal of Solid State Chemistry 182 (2009) 8–17
Table 4
˚
Selected bond distance (A) and angle (1) data for 3 (low and high temperature)
3 (low temperature)
Cu1–O6
1.9642(14)
1.9788(14)
2.0250(18)
2.0412(16)
2.2918(15)
1.9680(14)
2.0164(17)
2.0218(18)
2.0246(15)
2.2243(14)
N1–Cu1–O7
93.78(6)
87.64(6)
95.24(7)
88.58(6)
175.39(7)
160.15(6)
87.91(7)
87.63(7)
105.15(6)
87.92(6)
93.58(6)
94.53(5)
175.35(7)
111.22(5)
89.40(5)
Cu1–O8#1
Cu1–N1
N3#2–Cu1–O7
O1–Cu2–N6#3
O1–Cu2–N4
Cu1–N3#2
Cu1–O7
N6#3–Cu2–N4
O1–Cu2–O4#4
N6#3–Cu2–O4#4
N4–Cu2–O4#4
O1–Cu2–O3
N6#3–Cu2–O3
N4–Cu2–O3
Cu2–O1
Cu2–N6#3
Cu2–N4
Cu2–O4#4
Cu2–O3
O6–Cu1–O8#1
O6–Cu1–N1
O8#1–Cu1–N1
O6–Cu1–N3#2
O8#1–Cu1–N3#2
159.35(6)
90.18(6)
87.20(7)
93.44(6)
88.39(6)
O4#4–Cu2–O3
N1–Cu1–N3#2
O6–Cu1–O7
O8#1–Cu1–O7
3 (high temp.)
Cu1–O1
1.9629(13)
1.9987(15)
2.0261(15)
2.0296(15)
2.2715(16)
O1–Cu1–N3#6
O3#5–Cu1–N3#6
N1–Cu1–N3#6
O1–Cu1–O4
94.29(6)
88.25(6)
175.44(7)
107.72(5)
92.48(6)
93.57(6)
87.79(7)
Cu1–O3#5
Cu1–N1
Fig. 7. Plot of wmT vs T for 2. The solid line represents the best fit to Eq. (1).
Cu1–N3#6
Cu1–O4
O3#5–Cu1–O4
N1–Cu1–O4
O1–Cu1–O3#5
O1–Cu1–N1
O3#5–Cu1–N1
159.71(6)
89.45(6)
87.34(6)
N3#6–Cu1–O4
Symmetry transformations to generate equivalent atoms: (#1) x+1/2, ꢀy+2, z; (#2)
ꢀx+1, ꢀy+2, zꢀ1/2; (#3) ꢀx, ꢀy+1, z+1/2; (#4) xꢀ1/2, ꢀy+1, z; (#5) ꢀx+3/2, y+1/2,
z; (#6) ꢀx+3/2, ꢀy+1/2, zꢀ1/2.
Fig. 8. Plot of wmT vs T for 3. The solid line represents the best fit to Eq. (1).
remnant of 18.7% of the original is roughly consistent with the
deposition of Cu metal (17.4% calc’d). The TGA traces for 1–3 are
given in Figs. S1–S3.
5. Conclusions
Self-assembly of divalent transition metal cations, glutarate,
and the kinked diimine dpa has generated three isostructural
coordination polymers wherein neutral 1D [M(glu)]n chains
Fig. 9. Plot of wmT vs T for 1. The solid line represents the best fit to Eq. (2).
. . .
featuring close M
M contacts fostered by semi-ligation are
connected into 2D (4,4) rectangular grid layers. In the case of the
copper derivative, low energy conformational changes within the
glu ligand, with concomitant adjustment of hydrogen-bonding
pathways imparted by the amine functional groups of the
the glutarate ligands, in tandem with the kinked donor disposition
and hydrogen-bonding facility of the dpa tethers, results in a
. . .
. . .
family of coordination polymers with 1D [M
O–M
O–]n
chain motifs possessing varying magnetic interactions. The nickel
and copper derivatives show weak antiferromagnetic coupling
along the chain motifs; the variable temperature magnetic
behavior in both cases could be interpreted successfully using a
classic model. On the other hand, the cobalt analog exhibits
competing ferromagnetic ordering and zero-field effects, which
results in possible spin-canting behavior at low temperature.
Further work towards the synthesis of coordination polymers
dpa moieties, provides access to
a single crystal-to-single
crystal transformation between centrosymmetric and acentric
polymorphs.
The structures of 1–3 vary very significantly from their deri-
vatives incorporating either shorter or longer
a,o-dicarboxylate
ligands [15–16]. Among these succinate or adipate complexes,
only [Co(adipate)(dpa)]n possesses metal–metal contacts close
enough for magnetic communication, within its discrete {Co2}
dinuclear units. Thus, the unique conformational capabilities of
incorporating substituted or unsubstituted
a,o-dicarboxylate
ligands and tethering, hydrogen-bonding capable organodiimines

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17
[4] S.G. Baca, M.T. Reetz, R. Goddard, I.G. Filippova, Y.A. Simonov, M. Gdaniec,
N. Gerbeleu, Polyhedron 25 (2006) 1215;
H. Han, S. Zhang, H. Hou, Y. Fan, Y. Zhu, Eur. J. Inorg. Chem. (2006) 1594;
W. Mori, S. Takamizawa, C.N. Kato, T. Ohmura, T. Sato, Microporous
Mesoporous Mater. 73 (2004) 15.
[5] S. Zang, Y. Su, Y. Li, Z. Ni, Q. Meng, Inorg. Chem. 45 (2006) 174;
L. Wang, M. Yang, G. Li, Z. Shi, S. Feng, Inorg. Chem. 45 (2006) 2474;
S. Wang, Y. Hou, E. Wang, Y. Li, L. Xu, J. Peng, S. Liu, C. Hu, New J. Chem. 27
(2003) 1144.
[6] J. Tao, J.X. Shi, M.L. Tong, X.X. Zhang, X.M. Chen, Inorg. Chem. 40 (2001) 6328;
J. Tao, M.L. Tong, J.X. Shi, X.M. Chen, S.W. Ng, Chem. Commun. (2000) 2043;
J.C. Dai, X.T. Wu, Z.Y. Fu, C.P. Cui, S.M. Hu, W.X. Du, L.M. Wu, H.H. Zhang,
R.Q. Sun, Inorg. Chem. 41 (2002) 1391;
W. Chen, J.Y. Wang, C. Chen, Q. Yue, H.M. Yuan, J.S. Chen, S.N. Wang, Inorg.
Chem. 42 (2003) 944;
N. Hao, E. Shen, Y.B. Li, E.B. Wang, C.W. Hu, L. Xu, Eur. J. Inorg. Chem. (2004)
4102.
[7] W.-G. Lu, C.-Y. Su, T.-B. Lu, L. Jiang, J.-M. Chen, J. Am. Chem. Soc. 128 (2006)
34–35;
S. Horike, R. Matsuda, S. Kitagawa, Stud. Surf. Sci. Catal. 156 (2005) 725–732;
C. Qin, X.-L. Wang, Y.-G. Li, E.-B. Wang, Z.-M. Su, L. Xu, R. Clerac, Dalton Trans.
(2005) 2609–2614;
Y.-Q. Zheng, E.-R. Ying, Polyhedron 24 (2005) 397–406;
S.K. Ghosh, J. Ribas, P.K. Bharadwaj, Cryst. Growth Des. 5 (2005) 623–629;
X.-Z. Sun, Y.-F. Sun, B.-H. Ye, X.-M. Chen, Inorg. Chem. Commun. 6 (2003)
1412.
Fig. 10. Low temperature regime plot of wmT vs T for 1.
[8] L. Xu, G.-C. Guo, B. Liu, M.-S. Wang, J.-S. Huang, Inorg. Chem. Commun. 7
(2004) 1145.
[9] B. Chen, C. Liang, J. Yang, D.S. Contreras, Y.L. Clancy, E.B. Lobkovsky, O.M.
Yaghi, S. Dai, Angew. Chem. Int. Ed. 45 (2006) 1390.
[10] L.-S. Long, Y.-R. Wu, R.-B. Huang, L.-S. Zheng, Inorg. Chem. 43 (2004)
3798–3800.
is certain to afford materials with novel topologies and intriguing
physicochemical properties.
[11] Y.-Q. Zheng, J.-L. Lin, Z.-P. Kong, Inorg. Chem. 43 (2004) 2590.
[12] P.S. Mukherjee, S. Konar, E. Zangrando, T. Mallah, J. Ribas, N.R. Chaudhuri,
Inorg. Chem. 42 (2003) 2695.
6. Supplementary material
[13] L. Pan, H. Liu, X. Lei, X. Huang, D.H. Olson, N.J. Turro, J. Li, Angew. Chem. Int.
Ed. 42 (2003) 542.
[14] F.S. Delgado, M. Hernandez-Molina, J. Sanchiz, C. Ruiz-Perez, Y. Rodriguez-
Martin, J. Lopez, F. Lloret, M. Julve, CrystEngComm 6 (2004) 106.
[15] M.R. Montney, S. Mallika Krishnan, N.M. Patel, R.M. Supkowksi, R.L. LaDuca,
Cryst. Growth Des 7 (2007) 1145.
[16] M.R. Montney, S. Mallika Krishnan, N.M. Patel, R.M. Supkowksi, R.L. LaDuca,
Inorg. Chem. 46 (2007) 7362.
[17] D.P. Martin, R.M. Supkowksi, R.L. LaDuca, Inorg. Chem. 46 (2007) 7917.
[18] P.J. Zapf, R.L. LaDuca, R.S. Rarig, K.M. Johnson, J. Zubieta, Inorg. Chem. 37
(1998) 3411–3414.
Low temperature crystallographic data (excluding structure
factors) for 1 and 2 have been deposited with the Cambridge
Crystallographic Data Centre with Nos. 677975 and 677976.
The crystal structure data for
3 have CCDC Nos. 679062
(low temperature) and 677977 (high temperature). Copies of
the data can be obtained free of charge via the Internet at /http://
www.ccdc.cam.ac.uk/conts/retrieving.htmlS or by post at CCDC,
12 Union Road, Cambridge CB2 1EZ, UK (Fax: 44–1223336033,
Email: deposit@ccdc.cam.ac.uk).
[19] O. Khan, Molecular Magnetism, VCH Publishers, New York, 1993.
[20] SAINT, Software for Data Extraction and Reduction, Version 6.02, Bruker AXS,
Inc., Madison, WI, 2002.
[21] SADABS, Software for Empirical Absorption Correction, Version 2.03, Bruker
AXS, Inc., Madison, WI, 2002.
[22] G.M. Sheldrick, SHELXTL, Program for Crystal Structure Refinement, Uni-
versity of Gottingen, Gottingen, Germany, 1997.
Acknowledgments
The authors gratefully acknowledge Michigan State University
for financial support of this work. We thank Dr. Rui Huang (MSU)
for elemental analysis (SDG).
[23] M. Kurmoo, C. Estournes, Y. Oka, H. Kumagai, K. Inoue, Inorg. Chem. 44 (2005)
217.
[24] A.W. Addison, T.N.J. Rao, J. Chem. Soc., Dalton Trans. (1984) 1349.
[25] R.D. Shannon, Acta Cryst. A 32 (1976) 751.
[26] J.W. Steed, D.A. Tocher, Polyhedron 13 (1994) 167.
[27] V.A. Blatov, A.P. Shevchenko, V.N. Serezhkin, J. Appl. Crystallogr. 33 (2000)
1193.
Appendix A. Supplementary material
[28] B. Rather, M.J. Zaworotko, Chem. Commun. (2003) 830.
[29] M. Kondo, Y. Irie, Y. Shimizu, M. Miyazawa, H. Kawaguchi, A. Nakamura,
T. Naito, K. Maeda, F. Uchida, Inorg. Chem. 43 (2004) 6139;
T.K. Maji, K. Uemura, H.C. Chang, R. Matsuda, S. Kitagawa, Angew. Chem. Int.
Ed. 33 (2004) 3269;
Supplementary data associated with this article can be found
in the online version at 10.1016/j.jssc.2008.09.020.
M. Kurmoo, H. Kumagai, K.W. Chapman, C.J. Kepert, Chem. Commun. (2005)
3012;
M.H. Zeng, X.L. Feng, X.M. Chen, Dalton Trans. (2004) 2217;
D.V. Soldatov, G.D. Enright, J.A. Ripmeester, Chem. Mater. 14 (2002)
348.
References
[30] J.P. Zhang, Y.Y. Lin, W.X. Zhang, X.M. Chen, J. Am. Chem. Soc. 127 (2005)
14162;
[1] J.L.C. Roswell, O.M. Yaghi, Angew. Chem. Int. Ed. Engl. 44 (2005) 4670;
M. Kondo, T. Okubo, A. Asami, S.-I. Noro, T. Yoshitomi, S. Kitagawa, T. Ishii,
H. Matsuzaka, Angew. Chem. Int. Ed. Engl. 38 (1999) 140;
A.C. Sudik, A.R. Millward, N.W. Ockwig, A.P. Cote, J. Kim, O.M. Yaghi, J. Am.
Chem. Soc. 127 (2005) 7110.
K. Cheng, B.M. Foxman, J. Am. Chem. Soc. 99 (1977) 8102;
O.-S. Jung, S.H. Park, K.M. Kim, H.G. Jang, Inorg. Chem. 37 (1998) 5781;
Q. Chu, D.C. Swenson, L.R. MacGillivray, Angew. Chem. Int. Ed. 44 (2005)
3569;
[2] J.S. Seo, D. Whang, H. Lee, S.I. Jun, J. Oh, Y.J. Jeon, K. Kim, Nature 404 (2000)
982;
K. Cheng, B.M. Foxman, J. Am. Chem. Soc. 99 (1977) 8102.
[31] G.R. Desiraju, I.C. Paul, D.Y. Curtin, J. Am. Chem. Soc. 99 (1977) 1594.
[32] M.E. Fisher, Am. J. Phys. 32 (1964) 343.
A. Cingolani, S. Galli, N. Masciocchi, L. Pandolfo, C. Pettinari, A. Sironi, J. Am.
Chem. Soc. 127 (2005) 6144.
[33] J.M. Rueff, N. Masciocchi, P. Rabu, A. Sironi, A. Skoulios, Chem. Eur. J. 8 (2002)
1813.
[3] Q.-R. Fang, G.-S. Zhu, M. Xue, J.-Y. Sun, S.-L. Qiu, Shi-Lun, Dalton Trans. (2006)
2399;
X.-M. Zhang, M.-L. Tong, H.K. Lee, X.-M. Chen, J. Solid State Chem. (2001) 118;
O.M. Yaghi, H. Li, T.L. Groy, Inorg. Chem. 36 (1997) 4292.
[34] L.-M. Duan, F.-T. Xie, X.-Y. Chen, Y. Chen, Y.-K. Lu, P. Cheng, J.-Q. Xu, Cryst.
Growth Des. 6 (2006) 1101.