Reprint of structural diversity of cobalt(II) coordination compounds involving bent imidazole ligand: A route from 0D dimer to 3D coordination polymer

Article abstract of DOI:10.1016/j.poly.2013.02.002

Mixed ligand approach could be successfully applied to design porous three-dimensional coordination polymers, involving 1,3-bis(imidazol-1-yl)benzene (1,3-bib) as ligand. Five novel Co(II) compounds with different dimensionality have been synthesized. Utilizing only 1,3-bib in the solvothermal reaction with Co(II) salts, only molecular dimer Co₂(bib)₂Cl₄ or 1D polymer Co₂(1,3-bib)₂(NO₃)₂ could be synthesized. Copolymerization technique using additional linear dicarboxylates 1,4-benzenedicarboxylate (1,4-bdc) or 2,6- naphthalenedicarboxylate (2,6-ndc) facilitates the formation of 2D layered coordination polymers Co(1,3-bib)(1,4-bdc) and Co(1,3-bib)(2,6-ndc). Utilizing 4,4′-biphenyldicarboxylate (4,4′-bpdc) as a co-linker, a 3D metal-organic framework Co₃(1,3-bib)(4,4′-bpdc)₃ (DUT-58, DUT-Dresden University of Technology), possessing two interpenetrated uninodal 8-connected frameworks, has been obtained. DUT-58 exhibits a specific surface area of 1208 m²/g and adsorbs 27 mg/g hydrogen (maximum excess value at 30 bar and 77 K), 0.18 g/g n-butane (at 293 K) and 72 mg/g methane (maximum excess value at 60 bar and 298 K).

Full text of DOI:10.1016/j.poly.2013.02.002

Polyhedron 52 (2013) 1481–1488
Contents lists available at SciVerse ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
Reprint of ‘‘Structural diversity of cobalt(II) coordination compounds involving
bent imidazole ligand: A route from 0D dimer to 3D coordination polymer’’ q
⇑
Laura Schlechte, Volodymyr Bon, Ronny Grünker, Nicole Klein, Irena Senkovska , Stefan Kaskel
Department of Inorganic Chemistry, Dresden University of Technology, Bergstr. 66, D-01062 Dresden, Germany
a r t i c l e i n f o
a b s t r a c t
Article history:
Available online 8 February 2013
Mixed ligand approach could be successfully applied to design porous three-dimensional coordination
polymers, involving 1,3-bis(imidazol-1-yl)benzene (1,3-bib) as ligand. Five novel Co(II) compounds with
different dimensionality have been synthesized. Utilizing only 1,3-bib in the solvothermal reaction with
Co(II) salts, only molecular dimer Co2(bib)2Cl4 or 1D polymer Co2(1,3-bib)2(NO3)2 could be synthesized.
Copolymerization technique using additional linear dicarboxylates 1,4-benzenedicarboxylate (1,4-bdc)
or 2,6-naphthalenedicarboxylate (2,6-ndc) facilitates the formation of 2D layered coordination polymers
Co(1,3-bib)(1,4-bdc) and Co(1,3-bib)(2,6-ndc). Utilizing 4,40-biphenyldicarboxylate (4,40-bpdc) as a co-
linker, a 3D metal–organic framework Co3(1,3-bib)(4,40-bpdc)3 (DUT-58, DUT – Dresden University of
Technology), possessing two interpenetrated uninodal 8-connected frameworks, has been obtained.
DUT-58 exhibits a specific surface area of 1208 m2/g and adsorbs 27 mg/g hydrogen (maximum excess
value at 30 bar and 77 K), 0.18 g/g n-butane (at 293 K) and 72 mg/g methane (maximum excess value
at 60 bar and 298 K).
Dedicated to Alfred Werner on the 100th
Anniversary of his Nobel prize in Chemistry
in 1913
Keywords:
Cobalt(II)
Metal–organic framework
Imidazole ligand
Microporous material
Interpenetration
Ó 2013 Published by Elsevier Ltd.
1. Introduction
dle-wheel SBU allows to avoid interpenetration resulting in the
porous coordination polymers DUT-23 [14]. Several porous materi-
In the last two decades, the investigation of coordination poly-
mers (CP) or metal–organic frameworks (MOFs) was driven by
their high application potential. They are excellent materials for
gas storage [1], gas separation [2,3], sensor applications [4], as well
as heterogeneous catalysts or catalysts supports [5–7].
Beside of great application potential, MOFs are interesting mod-
el objects for crystallochemical investigations, since the dimen-
sionality of resulting compound can be, to some extent, directed
by synthetic conditions [8,9]. Among several approaches that are
used for the MOF synthesis, the co-polymerization of several link-
ers is a very effective one. For example, by copolymerization of
bitopic and tritopic carboxylates in the presence of zinc, as
Zn4O6+ source, highly porous materials such as UMCM family
[10,11], DUT-6 [12], or MOF-210 [13] could be obtained. Copoly-
merization of benzene-1,3,5-tribenzoate, 4,40-bipyridine with pad-
als (including flexible frameworks) were reported, which are copo-
lymerization products of carboxylic ligands (for example
tetracarboxylates, linear dicarboxylates) and nitrogen containing
ligands (such as 4,40-bipyridine, or 1,4-diazabicyclo [2.2.2] octane)
and paddle-wheel SBUs [15–19]. While coordination polymers ob-
tained using copolymerization approach from highly symmetrical
linear, trigonal and square-planar linkers are under intense inves-
tigation, we focus our efforts on the bent imidazole containing li-
gand, which also can be used as a linker (or as a co-linker) in
formation of frameworks with different dimensionality.
Herein, we report five novel Co(II) based compounds, where
1,3-bis(imidazole-1-yl)benzene (1,3-bib) was used as a linker or
co-linker. It should be mentioned that several structures involving
selected organic building block 1,3-bib are reported up to now, but
systematic investigation of coordination ability in term of multidi-
mensional framework formation using copolymerization synthesis
approach was not performed yet.
DOI of original article: http://dx.doi.org/10.1016/j.poly.2012.06.065
q
The publisher would like to inform the readership that this article is a reprint of
a previously published article. An error occurred on the publisher’s side which
resulted in the publication of this article in a wrong issue. As a consequence, the
publisher would like to make this reprint available for the reader’s convenience and
for the continuity of the special issue. For citation purposes, please use the original
publication details; L. Schlechte et al./Polyhedron 44 (2012) 179–186’. The
publisher sincerely apologizes to the readership and in particular to the author of
the respective article and deeply regrets the inconvenience caused.
2. Results and discussion
Taking into account the geometry of imidazole ring and flexibil-
ity around C—N bond, different conformations of the ligand occur.
As a result, the angle between nitrogen donor groups varies
slightly. Cobalt as an inorganic building block was chosen due to
its coordination versatility and capability to build various second-
⇑
Corresponding author. Tel.: +49 351 46332564; fax: +49 351 46337287.
E-mail address: irena.senkovska@chemie.tu-dresden.de (I. Senkovska).
0277-5387/$ - see front matter Ó 2013 Published by Elsevier Ltd.
http://dx.doi.org/10.1016/j.poly.2013.02.002

1482
L. Schlechte et al. / Polyhedron 52 (2013) 1481–1488
ary building units (SBUs). Thus, utilizing different synthesis condi-
tions and using commercially available carboxylic acids (H2(1,4-
bdc), H2(2,6-ndc), H2(4,40-bpdc)) as co-linkers, a series of coordina-
tion compounds with different dimensionality (from 0D to 3D) was
obtained (Scheme 1).
occupied by four bridging 1,3-bib ligands, forming chains along
[001] direction. The Co-N-bonds range between 2.11(9) and
2.13(2) Å (Table S2 ESI). The Co-O-bond has a length of 2.18(3) Å.
The Co. . .Co atoms distance in the polymeric chain is 10.59(9) Å.
Within the 1,3-bib ligands the imidazole rings are twisted with re-
spect to the benzene rings, forming a dihedral angles of 26.9(2) and
51.5(1)° with N2/C3/N3/C11/C12 and N1/C1/N4/C7/C2 imidazole
2.1. Co(1,3-bib)Cl2 (1)
rings. In the crystal structure, the chains are linked by
p–p-stack-
ing between benzene rings and by C—H. . . interactions between
p
Using CoCl2ꢀ6H2O as a metal source in solvothermal reaction
with 1,3-bib blue crystals of complex 1 were obtained. The single
crystal X-ray diffraction analysis reveals, that the compound crys-
imidazole rings (Fig. 2b and Table S3), strengthening the structure
in the [110] direction. The distances between the centers of the
phenyl rings lie in the range between 3.78(8) and 3.87(4) Å. Weak,
non classical hydrogen bonds are formed between the O atoms of
the nitrate groups and H atoms of the imidazole rings (Fig. 2c
and Table S3 ESI). The structure analog to 2, involving thiocyanate
anion instead of nitrate, was reported by Chung and co-workers
[21]. The linear geometry of thiocyanate anion, as well as the dihe-
dral angles value between phenyl and both imidazole moieties in
the linker molecule (42.2(2)°) cause symmetry increase (com-
pound crystallizes in the space group C2/m).
ꢀ
tallizes in P1 space group with a molecular dimeric Co2(1,3-bib)2-
Cl4 unit as a key element (Fig. 1a). The asymmetric unit contains
one-half of such molecular fragment. The Co atom shows nearly
regular tetrahedral coordination geometry containing two chlorine
and two nitrogen atoms. The Co—N and Co—Cl bond lengths have
expected values (Table S1 ESI). The valence angles around the Co
atom are in the range of 104.59(10)–112.30(5)°. The distance be-
tween symmetrically dependent Co1 atoms in the molecule
amounts to 10.304 Å. Within the 1,3-bib ligand, the benzene ring
is twisted with respect to the imidazole rings, forming dihedral an-
gles of 43.3(9)° and 46.0(7)° with the N1- and the N2-containing
imidazole rings. The formation of a weak hydrogen bonds C3—
H3. . .Cl1i (d(C3—Cl1i) = 3.685(5) Å, i: 2 ꢁ x, 1 ꢁ y, 1 ꢁ z) is observed
in the crystal structure of 1. They stabilize the crystal structure
along [101] direction (Fig. 1b). It should be mentioned, that Shu
and co-workers reported the zinc(II) based compound analogue
to compound 1, containing 1,3-bib and azide anion instead of chlo-
ride [20].
2.3. Co(1,3-bib)(1,4-bdc) (3)
Using the same synthesis conditions as applied for compound 2
and utilizing H2(1,4-bdc) as a co-linker, crystals of compound 3
could be obtained. The single crystal X-ray diffraction study reveals
polymeric structure containing 2D layers running parallel to (010)
plane. The centrosymmetric SBU is formed by two Co atoms
(Fig. 3a), that are held together by 2
l2-carboxylates from two
1,4-bdc linkers forming a chain (Fig. 3b). The 1,3-bib molecules
in this case have a function of an auxiliary linkers, strengthening
the chains. The chains are interconnected along c by further 1,4-
bdc molecules, which act as bidentate chelate ligands (Fig. 3c).
The coordination geometry of the Co atom can be described as a
strongly distorted octahedron. The Co—O and Co—N distances are
in the range of 2.009(3)–2.280(3) and 2.113(4)–2.127(4) Å, respec-
tively (Table S4 ESI). The adjacent angles of Co polyhedron are in
range of 58.99(12)–94.44(14) Å. The Co. . .Co distance within the
SBU amount to 4.268(2) Å. The described layers are held together
2.2. Co(1,3-bib)(NO3) (2)
Under similar synthesis conditions, but utilizing cobalt nitrate
instead of cobalt chloride as a metal source, pink crystals of 2 were
obtained. In the structure of 2 the Co atom is coordinated by four N
atoms of four 1,3-bib ligands and two oxygen atoms of two nitrate
groups resulting in a distorted CoN4O2-type octahedral coordina-
tion polyhedron with adjacent angles in the range of 83.45(6)–
96.55(6)° (Fig. 2a). The equatorial positions of the octahedron are
Scheme 1. Schematic representation of the synthetic route for compounds (1–5). Blue balls indicate Co atoms or SBU, red balls – carboxylate, black balls – 1,3-bib linker. Red
and blue balls in the representation of structure 5 correspond to the Co SBUs of two interpenetrated frameworks. (Color online.)

L. Schlechte et al. / Polyhedron 52 (2013) 1481–1488
1483
Fig. 1. Crystal structure of 1. (a) (ORTEP) representation of dimer in 1 with labeling scheme (i = ꢁx + 1, ꢁy + 1, ꢁz + 1). (b) Packing diagram of 1 (dashed lines indicate weak
intramolecular interactions).
Fig. 2. Crystal structure of 2. (a) Fragment of 1D chain with atom labeling scheme. (b) View of the structure along b axis showing
p–p-stacking and C—H. . .p interactions as
dished lines. The H atoms not involved in the hydrogen bonding are omitted for clarity. (c) Packing diagram along a direction involving intermolecular C—H. . .O interactions.
by intra- and interlayer C—H. . .
direction (Table S5 ESI).
p
and
p
. . .
p
interactions along c
boxylic group in syn fashion (Fig. 4b). It should be mentioned that
in the case of 4, 1,3-bib linker shows another conformation, than in
compound 1. The dihedral angles between the imidazole (N1/N2/
C13/C14/C15; N3/N4/C19/C20/C21) and the phenyl (C16/C17/
C18/C22/C23/C24) rings amounts to 19.8(2) and 42.8(3)°, respec-
tively. The distance between Co atoms in adjacent layers is
7.661(2) Å. The neighboring layers are interconnected by numer-
2.4. Co(1,3-bib)(2,6-ndc) (4)
Utilizing H2(2,6-ndc) as a co-linker under the same synthetic
conditions, the crystalline precipitate of compound 4 was obtained.
In the structure of 4, Co atoms have distorted CoN2O2 tetrahedral
coordination geometry (Fig. 4a) and do not form a SBU, but act
as single atom connectors. The Co—O and Co—N bond lengths are
in the close range of 1.969(3)–2.039(4) Å (Table S6 ESI). The crystal
structure is built up from 2D layers, running parallel to the (101)
plane. The layers are created from Co2(1,3-bib)24+dimmers, similar
to those found in compound 1 in which chlorine anions are substi-
tuted by 2,6-ndc linker, coordinating by one oxygen from each car-
ous
p–p-stacking and C—H. . .p interactions (Fig. 4c and Table S7
ESI).
2.5. Co3(1,3-bib)(4,40-bpdc)3 (5) DUT-58
Utilizing the longer linear ligand H2(4,40-bpdc) under the main-
taining other synthetic conditions, the crystals of DUT-58 (5) were
obtained. The crystal structure of 5 contains two interpenetrated

1484
L. Schlechte et al. / Polyhedron 52 (2013) 1481–1488
Fig. 3. Crystal structure of 3. (a) SBU. (b) View on 2D layer along b direction. (c)
Packing diagram along c direction. In (a) and (c) hydrogen atoms are omitted for
clarity.
Fig. 4. Crystal structure of 4. (a) Thermal ellipsoid plot of the network fragment,
involving numbering scheme. (b) Fragment of the 2D network along [111]
3D frameworks, related by inversion center. The Co atoms form a
linear Co3(COO)6 SBU (Fig. 5a), common for Co containing MOFs
[22,23]. Co1–Co3 and Co1–Co2 distances amount to 3.215(2) and
3.511(2) Å, respectively. The coordination polyhedrons of the Co2
and Co3 atoms can be described as strongly distorted trigonal
bipyramids (Table S8 ESI). Co1 atom has nearly regular octahedral
CoO6 coordination sphere. In the SBU, the adjacent Co atoms are
direction. (c) Crystal packing diagram showing intermolecular
interactions. Hydrogen atoms are omitted.
p–p-stacking
The similar layers formation was reported by Volkmer and co-
workers [24] for mixed-metal compound with the composition
Zn2Co(4,40-bpdc)3(DMF)2. This structure consists of layers, because
the axial coordination positions of SBUs are saturated by solvent
DMF molecules preventing the formation of 3D structure.
These layers in the structure of DUT-58 are interconnected by
1,3-bib pillar molecules, coordinated in the axial positions of the
SBU, forming a 8-connected 36418536 net (i.e., hexagonal primitive
lattice). The single framework possesses triangular channels along
interconnected by two 4,40-bpdc ligands coordinating in
boxylato- O:
O0 fashion (Fig. 5a). The third 4,40-bpdc linker
(involving O1, O2, O3, and O4 oxygen atoms) coordinates the Co
atom in 3-fashion, resulting in one bridging function of the car-
l-car-
j
j
l
boxylic oxygen of each carboxylic group (O1 and O3). Such connec-
tivity facilitates the creation of the 2D layer, running parallel to
(011) plane.

L. Schlechte et al. / Polyhedron 52 (2013) 1481–1488
1485
Fig. 5. Crystal structure of 5 (DUT-58). (a) SBU geometry. (b) View on a single framework along b direction. (c) Representation of the interpenetrated frameworks along [101]
direction.
[101] direction (Fig. 5c) and square channels along [010] (Fig. 5b)
crystallographic directions. In spite of interpenetration, after
removing the lattice solvent molecules from the crystal structure,
the solvent accessible volume, calculated using PLATON [25],
amount to 43.1% of the unit cell volume.
exchange to CH2Cl2 (DCM) was undertaken. After removing of
DCM in argon steam at room temperature, DUT-58 was addition-
ally activated thermally at 120 °C for 24 h. The crystallinity of the
dried sample was confirmed by X-ray powder diffraction (Fig. S5
ESI).
Interestingly, compounds isoreticular to DUT-58 could be ob-
The nitrogen physisorption measurement at ꢁ196 °C reveals
type I isotherm, which reaches saturation at 300 cm3/g (Fig. 6a)
and confirms microporous nature of the material. The multipoint
specific surface area was calculated using the BET method in the
low pressure region and amounts to 1208 m2/g. The total pore vol-
ume is 0.47 cm3/g (p/p0 = 0.996). Hydrogen excess physisorption
isotherm measured at ꢁ196 °C (Fig. 6b) shows a maximum at
30 bar. The hydrogen storage capacity of DUT-58 is 27.3 mg/g
(2.64 wt.%). Methane adsorption capacity was studied at 25 °C up
to 150 bar (Fig. 6d). DUT-58 has a maximum excess uptake of
72 mg/g at 60 bar.
tained by using only 4,40-bpdc, which act as linker within the layer
+
and as a pillar between the layers [26,27] (in this case NMe4 as
counter ions are present inside the pores), as well as by using
4,40-bipyridine as pillar [28]. For the last compound (named
IRPM-1) the pore volume of 0.25 cm3/g based on the n-hexane
adsorption was reported.
2.6. Thermogravimetric analysis
Thermal stability of compounds 1–5 was investigated by ther-
mogravimetric analysis. The decomposition of compound 1, which
does not contain any solvent, occurs at the temperatures higher
than 310 °C (Fig. S9 ESI). Compound 2 loses the free solvent mole-
cules at 30–140 °C, and the following weight loss, starting at
270 °C, is caused by decomposition of the whole skeleton
(Fig. S10 ESI).
The compounds 3–5, which all contain additional carboxylic
linkers show enhanced thermostability in comparison to 1 and 2.
The decomposition of 2D and 3D frameworks is shifted to higher
temperatures and take place at 360 °C for compound 3 (Fig. S11
ESI), at 375 °C for compound 4 (Fig. S12 ESI) and at 350 °C for com-
pound 5 (Fig. S13 ESI).
3. Conclusions
Summarizing, five Co(II) coordination compounds involving
1,3-bib, possessing different dimensionality have been synthe-
sized. It has been shown that using solely 1,3-bib ligand in the
solvothermal synthesis, the dimer complex or 1D coordination
polymer could be obtained. Using the dicarboxylates (1,4-bdc,
2,6-ndc) as co-linker, the compounds showing 2D layered struc-
tures were obtained. The co-polymerization of Co2+, 1,3-bib and
4,40-bpdc led to the formation of a microporous metal–organic
framework, named DUT-58, with
a specific surface area of
1208 m2/g. The crystal structure of DUT-58 consists of two inter-
penetrated uninodal 8-connected frameworks adopting hexagonal
primitive topology. High pressure adsorption experiments show
excess uptake of 27 mg/g (30 bar) for hydrogen and 72 mg/g for
methane. The n-butane adsorption capacity is 0.18 g/g.
2.7. Physisorption measurements
The accessibility of the pores in DUT-58 was studied by gas
physisorption experiments. Prior the measurements, the solvent

1486
L. Schlechte et al. / Polyhedron 52 (2013) 1481–1488
Fig. 6. Physisorption isotherms of DUT-58: nitrogen (ꢁ196 °C); hydrogen high pressure excess (ꢁ196 °C); n-butane (20 °C); methane high pressure excess (25 °C). Adsorption
(d) and desorption (s).
4.1.2. Synthesis of Co(1,3-bib)Cl2 (1)
4. Experimental
CoCl2ꢀ6H2O (23.7 mg, 0.1 mmol) and 1,3-bib (21 mg 0.1 mmol)
were dissolved separately in DMF (2 mL). The mixture was soni-
cated for 1 min and heated at 353 K for 48 h. After cooling to room
temperature the product was isolated by decanting the mother li-
quor and washed with DMF. For elemental analysis and TGA the
product was dried under argon at room temperature for 6 h. Yield
55% (based on 1,3-bib). Elemental analysis Calc. (%) for C12H10N4-
Cl2Co (Co(1,3-bib)Cl2): C 42.38; H 2.96; N 16.47. Found: C 42.53;
4.1. Materials
CoCl2ꢀ6H2O was purchased from Fluka Analytical. Co(NO3)2-
ꢀ6H2O was purchased from ChemPur. Both were used as received.
N,N-dimethylformamide (DMF) was distilled from phosphorus
pentoxide and stored under argon.
H 2.86; N 16.45. IR:
m
/cmꢁ1 = 3097 (w); 3048 (w); 1668 (m);
4.1.1. Synthesis of 1,3-bis(imidazol-1-yl)benzene (1,3-bib)
1599 (m); 1513 (s); 1404 (w); 1386 (w); 1245 (s); 1070 (s);
956 (w); 944 (w); 929 (w); 900 (w); 799 (s); 779 (s); 767 (s);
749 (s); 693 (s) (see Fig. S6 ESI).
A Schlenk flask was loaded with CuI (2.74 g, 14.4 mmol), N,N-
dimethylglycine (2.97 g, 28.8 mmol), K2CO3 (39.79 g, 288 mmol)
and imidazole (12.24 g, 180 mmol). The system was evacuated
and filled with argon. 1,3-Dibromobenzene (16.92 g, 72 mmol)
and 350 mL DMSO were added. The mixture was heated at 393 K
for 48 h. After that the mixture was cooled down to room temper-
ature and segregated between water and ethyl acetate. The organic
layer was separated and the aqueous fraction was extracted with
ethyl acetate twice. The combined organic layers were washed
with NaHCO3, dried over MgSO4 and concentrated in vacuum.
The residue was purified by column chromatography (dichlorme-
thane/methanol (10:1)) and recrystallized from methanol to give
white crystals of 1,3-bib. Yield 69% (based on 1,3-dibromoben-
zene); dH(500 MHz, CDCl3) 7.90 (s, 2H, H-5), 7.60 (t, J = 8.2 Hz,
1H, H-1), 7.42 (m, 2H, H-7), 7.39 (d, J = 1.9 Hz, 1H, H-4), 7.32 (m,
2H, H-2), 7.24 (m, 2H, H-6); dC(125 MHz, CDCl3) 138.76 (C-3,
4.1.3. Synthesis of Co(1,3-bib)(NO3)2(DMF)2 (2)
Co(NO3)2ꢀ6H2O (26.2 mg, 0.1 mmol) and 1,3-bib (21 mg,
0.1 mmol) were dissolved separately in DMF (2 mL). The mixture
was sonicated for 1 min and heated at 373 K for 24 h. After cooling
to room temperature the product was isolated by decanting the
mother liquor and washed with DMF. For elemental analysis and
TGA the product was dried under argon at room temperature for
6 h. Yield 86% (based on 1,3-bib). Elemental analysis Calc. (%) for
C
30H34O8N12Co (Co(1,3-bib)(NO3)2(DMF)2): C 48.09; H 4.57; N
22.43. Found: C 48.16; H 4.40; N 22.30. IR:
m
/cmꢁ1 = 3121 (w);
2929 (w); 2867 (w); 1663 (m); 1614 (w); 1508 (m); 1403 (m);
1385 (m); 1292 (s); 1246 (s); 1120 (w); 1066 (s); 1033 (m); 935 (m);
890 (m); 851 (w); 790 (w); 768 (w); 741 (m); 687 (m); 657 (s)
(see Fig. S6 ESI).
C
quart), 135.53 (C-5, CH), 131.55 (C-1, CH), 131.07 (C-6, CH),
120.22 (C-2, CH), 118.09 (C-7, CH), 114.58 (C-4, CH); Mp: 144 °C.
IR:
/cmꢁ1 = 3099 (m), 1610 (m), 1599 (m), 1497 (s), 1482 (s),
m
1377 (w), 1296 (m), 1248 (s), 1106 (m), 1059 (s), 1000 (m),
955 (m), 905 (m), 880 (s), 833 (w), 797 (s), 769 (s), 745 (s),
724 (s), 688 (s), 652 (m).
4.1.4. Synthesis of [Co(1,3-bib)(1,4-bdc)](DMF)0.5(H2O)0.5 (3)
Co(NO3)2ꢀ6H2O (26.2 mg, 0.1 mmol) and H2(1,4-bdc) (16.6 mg,
0.1 mmol) were dissolved in 9 mL DMF. 1,3-bib (21 mg, 0.1 mmol)

L. Schlechte et al. / Polyhedron 52 (2013) 1481–1488
1487
was dissolved separately in 1 mL DMF. After sonification for 1 min
the solutions were mixed, transferred into a Teflon vessel (25 cm3)
and heated in an autoclave at 393 K for 48 h. After cooling to room
temperature the product was isolated by decanting the mother li-
quor and washed with DMF. For elemental analysis and TGA the
product was dried under argon at room temperature for 6 h. Yield
81% (based on 1,3-bib). Elemental analysis Calc. (%) for C20H14O4N4-
Co (Co(1,3-bib)(1,4-bdc)(DMF)0.5(H2O)0.5): C 53.93; H 3.89; N
perature for 6 h. Yield 64% (based on H2(4,40-bpdc)). Elemental
analysis Calc. (%) for C57H41O13N5Co3 (Co3(1,3-bib)(4,40-bpdc)3
(DMF)2(H2O)): C 56.30; H 4.27; N 7.29. Found: C 55.94; H 4.01;
N 7.65. IR:
m
/cmꢁ1 = 1666 (m); 1596 (m); 1513 (m); 1382 (s);
1254 (w); 1176 (w); 1090 (w); 1061 (w); 1006 (w); 855 (w);
769 (s); 679 (w) (see Fig. S8 ESI).
4.2. Single crystal measurements
13.16. Found: C 54.05; H 3.61; N 13.08. IR:
m
/cmꢁ1 = 3144 (w);
1667 (m); 1599 (s); 1566 (m); 1500 (s); 1441 (w); 1384 (s);
1320 (m); 1280 (m); 1248 (m); 1114 (w); 1057 (m); 931 (m);
822 (m); 779 (w); 751 (s); 676 (w) (see Fig. S7 ESI).
Suitable crystals were selected under polarized light, washed
with solvent and prepared in a sealed glass capillary in a solvent
atmosphere. Measurements were performed on a STOE IPDS 2 dif-
fractometer equipped with long focused X-ray tube with Mo-anode
and a graphite monochromator (k = 0.71073 Å). The integrated
intensities were corrected for Lorentz and polarization using X-
Area software [29]. The numerical adsorption correction was ap-
plied to datasets of 1, 2, and 4 using X-red32 program. Crystal
structures were solved by direct methods and refined by full ma-
trix least-square on F2 using SHELX program package [30]. All non
hydrogen atoms were refined in anisotropic approximation. The
positions of hydrogen atoms were calculated geometrically regard-
ing hybridization of parent atom and refined using ‘‘riding’’ model.
Due to irresolvable disorder of guest solvent molecules, observed
in crystal structures of 3, 4 and 5, solvent molecule contributions
have been removed from the intensity data via the SQUEEZE rou-
tine as implemented in PLATON. The topology of the framework
was analyzed using program TOPOS 4.0 [31]. The crystallographic
data for compounds 1–5 are summarized in Table 1.
4.1.5. Synthesis of [Co(1,3-bib)(2,6-ndc)](DMF)1.5(H2O)1.5 (4)
Co(NO3)2ꢀ6H2O (26.2 mg, 0.1 mmol) and H2(2,6-ndc) (21.6 mg,
0.1 mmol) were dissolved in 9 mL DMF. 1,3-bib (21 mg, 0.1 mmol)
was dissolved separately in 1 mL DMF. After sonification for 1 min
the solutions were mixed, transferred into a Teflon vessel (25 cm3)
and heated in an autoclave at 393 K for 48 h. After cooling to room
temperature the product was isolated by decanting the mother li-
quor and washed with DMF. For elemental analysis and TGA the
product was dried under argon at room temperature for 6 h. Yield
89% (based on 1,3-bib). Elemental analysis Calc. (%) for C24H16O4N4-
Co (Co(1,3-bib)(2,6-ndc)(DMF)1.5(H2O)1.5): C 55.21; H 4.8; N 12.43.
Found: C 55.01; H 4.54; N 12.81. IR: m
/cmꢁ1 = 3133 (w); 1656 (m);
1602 (m); 1574 (m); 1512 (m); 1494 (m); 1385 (s); 1342 (s);
1286 (m); 1253 (m); 1196 (m); 1095 (m); 1064 (s); 959 (w);
942 (w); 922 (w); 836 (w); 786 (s); 747 (m); 684 (w) (see Fig. S7
ESI).
4.3. Adsorption measurements
4.1.6. Synthesis of [Co3(1,3-bib)(4,40-bpdc)3](DMF)2(H2O) (5)
Co(NO3)2ꢀ6H2O (52.4 mg, 0.2 mmol) and H2(4,40-bpdc)
(48.4 mg, 0.2 mmol) were dissolved in 23 mL DMF. 1,3-bib
(31.5 mg, 0.15 mmol) was dissolved separately in 2 mL DMF. After
sonification for 1 min the solutions were mixed, transferred into a
Teflon vessel (50 cm3) and heated in an autoclave at 393 K for 48 h.
After cooling to room temperature the product was isolated by
decanting the mother liquor and washed with DMF. For elemental
analysis and TGA the product was dried under argon at room tem-
Nitrogen physisorption measurements up to 1 bar at 77 K were
carried out using a Quantachrome Autosorb1C apparatus. High
pressure H2 adsorption measurement at 77 K up to 80 bar was per-
formed using a volumetric BELSORP HP apparatus. High pressure
CH4 adsorption was studied using a magnetic suspension balance
(Rubotherm). Adsorption measurement of n-butane was per-
formed with a micro-balance (B111, Setaram) at 293 K and atmo-
spheric pressure under dynamic conditions (n-butane diluted
Table 1
Crystallographic data for compounds 1–5.
1
C
2
3
4
5
Formula
24H20Cl4Co2N8
C30H34CoN12O8
749.62
triclinic
C20H14CoN4O4
433.28
monoclinic
C2/c
C24H16CoN4O4
483.34
triclinic
C57H41Co3N5O13
1180.74
monoclinic
C2/c
Molecular weight
Crystal system
Space group
Unit cell dimensions
a (Å)
680.14
triclinic
P1
ꢀ
ꢀ
ꢀ
P1
P1
7.497(2)
9.232(3)
10.349(3)
91.160(9)
95.263(7)
105.181(7)
687.6(4)
1
8.9989(3)
9.8166(4)
10.5995(7)
102.359(3)
100.875(3)
107.415(2)
840.02(7)
1
21.745(5)
14.720(6)
15.091(3)
90
119.52(3)
90
4203(2)
8
1.369
11.825(2)
12.158(2)
12.764(3)
68.57(3)
81.97(3)
67.12(3)
1573.8(5)
2
44.781(9)
13.959(3)
26.181(5)
90
119.71(3)
90
14214(5)
8
1.103
b (Å)
c (Å)
a
(°)
b (°)
c
(°)
Volume (Å3)
Z
Calculated density (g cmꢁ3
)
1.642
1.625
342
1.482
0.580
389
1.020
0.572
494
Absorption coefficient (mmꢁ1
F(000)
)
0.848
1768
0.745
4824
Reflections collected/unique
5710/2677
(Rint = 0.0435)
2677/0/172
0.953
10342/3427
(Rint = 0.0328)
3427/0/234
1.068
9971/3524
(Rint = 0.0791)
3524/0/262
0.730
10328/5085
(Rint = 0.0505)
5085/1/298
0.952
46253/11911
(Rint = 0.1960)
11911/0/705
0.634
Data/restrains/parameters
Goodness-of-fit on F2
Final R indices [I > 2
R indices (all data)
r
(I)]
R1 = 0.0477
wR2 = 0.0784
R1 = 0.1110
wR2 = 0.0975
0.357/ꢁ0.386
R1 = 0.0394
wR2 = 0.0879
R1 = 0.0519
wR2 = 0.0930
0.354/ꢁ0.334
R1 = 0.0447
wR2 = 0.0877
R1 = 0.1063
wR2 = 0.0995
0.240/ꢁ0.605
R1 = 0.0593
wR2 = 0.1582
R1 = 0.0881
wR2 = 0.1661
0.675/ꢁ0.382
R1 = 0.0587
wR2 = 0.1301
R1 = 0.1279
wR2 = 0.1436
0.602/ꢁ0.845
Largest difference in peak and hole (Åꢁ3
)

1488
L. Schlechte et al. / Polyhedron 52 (2013) 1481–1488
[7] D. Farrusseng, S. Aguado, C. Pinel, Angew. Chem., Int. Ed. 48 (2009) 7502.
[8] I. Senkovska, J. Fritsch, S. Kaskel, Eur. J. Inorg. Chem. (2007) 5475.
[9] I.M. Hauptvogel, V. Bon, R. Grünker, I.A. Baburin, I. Senkovska, U. Mueller, S.
Kaskel, Dalton Trans. 41 (2012) 4172.
with nitrogen). High purity gases were used: N2: 99.999%, H2:
99.999%, CH4: 99.5%, and n-C4H10: 99.95%.
[10] K. Koh, A.G. Wong-Foy, A.J. Matzger, J. Am. Chem. Soc. 131 (2009) 4184.
[11] K. Koh, A.G. Wong-Foy, A.J. Matzger, Angew. Chem., Int. Ed. 47 (2008) 677.
[12] N. Klein, I. Senkovska, K. Gedrich, U. Stoeck, A. Henschel, U. Mueller, S. Kaskel,
Angew. Chem., Int. Ed. 48 (2009) 9954.
[13] H. Furukawa, N. Ko, Y.B. Go, N. Aratani, S.B. Choi, E. Choi, A.Ö. Yazaydin, R.Q.
Snurr, M. O’Keeffe, J. Kim, O.M. Yaghi, Science 329 (2010) 424.
[14] N. Klein, I. Senkovska, I.A. Baburin, R. Grünker, U. Stoeck, M. Schlichtenmayer,
B. Streppel, U. Mueller, S. Leoni, M. Hirscher, S. Kaskel, Chem. Eur. J. 17 (2011)
13007.
Acknowledgments
The authors are grateful for the financial support of the German
Research Foundation (SPP 1362). A special thank to Florian Wisser
for the performance of the infrared spectroscopic measurements
and Anke Peritz for the performance of the elemental analyses.
[15] H.-T.S.P.M. Barron, C. Hu, W. Choe, Cryst. Growth Des. 9 (2009) 1960.
[16] Z. Chang, D.-S. Zhang, Q. Chen, R.-F. Li, T.-L. Hu, X.-H. Bu, Inorg. Chem. 50
(2011) 7555.
Appendix A. Supplementary data
[17] N. Klein, C. Herzog, M. Sabo, I. Senkovska, J. Getzschmann, S. Paasch, M.R. Lohe,
E. Brunner, S. Kaskel, Phys. Chem. Chem. Phys. 12 (2010) 11778.
[18] H. Wang, J. Getzschmann, I. Senkovska, S. Kaskel, Microporous Mesoporous
Mater. 116 (2008) 653.
[19] D.N. Dybtsev, H. Chun, K. Kim, Angew. Chem. 116 (2004) 5143.
[20] W.-D. Xu, M.-H. Shu, Acta Crystallogr., Sect. E 62 (2006) m3341.
[21] S.U. Son, K.H. Park, B.Y. Kim, Y.K. Chung, Cryst. Growth Des. 3 (2003) 507.
[22] P. Wollmann, M. Leistner, U. Stoeck, R. Grünker, K. Gedrich, N. Klein, O. Throl,
W. Grählert, I. Senkovska, F. Dreisbach, S. Kaskel, Chem. Commun. 47 (2011)
5151.
CCDC 874391–874395 contains the supplementary crystallo-
graphic data for complexes 1–5. These data can be obtained free
of charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html, or
from the Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: (+44) 1223 336 033; or e-mail: de-
posit@ccdc.cam.ac.uk. Supplementary data associated with this
article can be found, in the online version, at http://dx.doi.org/
10.1016/j.poly.2012.06.065.
[23] D.J. Tranchemontagne, J.L. Mendoza-Cortes, M. O’Keeffe, O.M. Yaghi, Chem.
Soc. Rev. 38 (2009) 1257.
References
[24] Y. Wang, B. Bredenkotter, B. Rieger, D. Volkmer, Dalton Trans. (2007) 689.
[25] A.L. Spek, Utrecht University, Utrecht, The Netherlands, 2008.
[26] Y. Du, A.L. Thompson, N. Russell, D. O’Hare, Dalton Trans. 39 (2010) 3384.
[27] F. Luo, Y.-X. Che, J.-M. Zheng, Chem. Eur. J. 9 (2008) 1066.
[28] L. Pan, H. Liu, X. Lei, X. Huang, D.H. Olson, N.J. Turro, J. Li, Angew. Chem., Int. Ed.
42 (2003) 542.
[29] Stoe & Cie GmbH, Darmstadt, Germany, 2008.
[30] G. Sheldrick, Acta Crystallogr., Sect. A 64 (2008) 112.
[31] V.A. Blatov, IUCr Compcomm Newsletter 7 (2006) 4.
[1] V.C. Menon, S. Komarneni, J. Porous Mater. 5 (1998) 43.
[2] J.R. Li, R.J. Kuppler, H.C. Zhou, Chem. Soc. Rev. 38 (2009) 1477.
[3] S.T. Meek, J.A. Greathouse, M.D. Allendorf, Adv. Mater. 23 (2011) 249.
[4] M.C. Das, S. Xiang, Z. Zhang, B. Chen, Angew. Chem., Int. Ed. 50 (2011) 10510.
[5] G. Nickerl, A. Henschel, R. Grünker, K. Gedrich, S. Kaskel, Chem. Ing. Tech. 83
(2011) 90.
[6] A. Corma, H. Garcia, F.X.L. Xamena, Chem. Rev. 110 (2010) 4606.