Two mononuclear octa-hedral complexes with benzimidazole-2-carboxyl-ate: Supra-molecular networks constructed by hydrogen bonds

Article abstract of DOI:10.1107/S0108270111041837

The title compounds, trans-bis-(1H-benzimidazole-2-carbox-ylato- κ² N³,O)bis-(ethanol-κO)cadmium(II), [Cd(C₈H₅N₂O₂)₂(C ₂H₆O)₂], (I), and trans-bis-(1H-benzimidazole- κN³)bis-(1H-benzimidazole-2-carboxyl-ato-κ² N³,O)nickel(II), [Ni(C₈H₅N₂O ₂)₂(C₇H₆N₂)₂], (II), are hydrogen-bonded supra-molecular complexes. In (I), the Cd ^II ion is six-coordinated by two O atoms from two ethanol mol-ecules, and by two O and two N atoms from two bidentate benzimidazole-2-carboxyl-ate (HBIC) ligands, giving a distorted octa-hedral geometry. The combination of O-H...O and N-H...O hydrogen bonds results in two-dimensional layers parallel to the ab plane. In (II), the six-coordinated Ni^II atom, which lies on an inversion centre, shows a similar distorted octa-hedral geometry to the Cd^II ion in (I); two benzimidazole mol-ecules occupy the axial sites and the equatorial plane contains two chelating HBIC ligands. Pairs of N-H...O hydrogen bonds between pairs of HBIC anions connect adjacent Ni^II coordination units to form a one-dimensional chain parallel to the a axis. Moreover, these one-dimensional chains are further linked via N-H...O hydrogen bonds between HBIC anions and benzimidazole mol-ecules to generate a three-dimensional supra-molecular framework. The two compounds show quite different supra-molecular networks, which may be explained by the fact that different co-ligands occupy the axial sites in the coordination units.

Full text of DOI:10.1107/S0108270111041837

metal-organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
features and properties (Kitaura et al., 2003; Custelcean et al.,
2006; Madalan et al., 2006; Jiang et al., 2008, 2009). It has been
demonstrated that the number and orientation of weak
attraction sites on the discrete building blocks have a signifi-
cant effect on the resulting supramolecular structures. Thus,
minor changes in interaction sites in the building blocks may
affect the packing and even the overall network. Related
studies will help us rationally design crystallized materials with
desirable structures.
ISSN 0108-2701
Two mononuclear octahedral
complexes with benzimidazole-2-
carboxylate: supramolecular networks
constructed by hydrogen bonds
Jun Fan, Song-Liang Cai, Sheng-Run Zheng and
Wei-Guang Zhang*
School of Chemistry and Environment, South China Normal University, Guangzhou
510006, People’s Republic of China
Correspondence e-mail: wgzhang@scnu.edu.cn
Received 21 June 2011
Accepted 11 October 2011
Online 25 October 2011
The title compounds, trans-bis(1H-benzimidazole-2-carbox-
ylato-ꢀ2N3,O)bis(ethanol-ꢀO)cadmium(II), [Cd(C8H5N2O2)2-
(C2H6O)2], (I), and trans-bis(1H-benzimidazole-ꢀN3)bis(1H-
benzimidazole-2-carboxylato-ꢀ2N3,O)nickel(II), [Ni(C8H5-
N2O2)2(C7H6N2)2], (II), are hydrogen-bonded supramolecular
complexes. In (I), the CdII ion is six-coordinated by two O
atoms from two ethanol molecules, and by two O and two N
atoms from two bidentate benzimidazole-2-carboxylate
(HBIC) ligands, giving a distorted octahedral geometry. The
combination of O—Hꢀ ꢀ ꢀO and N—Hꢀ ꢀ ꢀO hydrogen bonds
results in two-dimensional layers parallel to the ab plane. In
(II), the six-coordinated NiII atom, which lies on an inversion
centre, shows a similar distorted octahedral geometry to the
CdII ion in (I); two benzimidazole molecules occupy the axial
sites and the equatorial plane contains two chelating HBIC
ligands. Pairs of N—Hꢀ ꢀ ꢀO hydrogen bonds between pairs of
HBIC anions connect adjacent NiII coordination units to form
a one-dimensional chain parallel to the a axis. Moreover, these
one-dimensional chains are further linked via N—Hꢀ ꢀ ꢀO
hydrogen bonds between HBIC anions and benzimidazole
molecules to generate a three-dimensional supramolecular
framework. The two compounds show quite different supra-
molecular networks, which may be explained by the fact that
different co-ligands occupy the axial sites in the coordination
units.
The assembly of complexes based on bis(chelating) bridging
ligands has been of intense interest, mainly because of the
multiple coordination modes of these ligands, intriguing
structural features and the potential properties of the resulting
complexes (Zhang, Cheng et al., 2008; Zhang, Ma et al., 2008;
Colacio et al., 2009; Mota et al., 2010). For example, a great
many magnetically ordered materials based on oxalate and its
derivatives have been explored in recent years (Ruiz et al.,
1999; Xu et al., 2007; Train et al., 2008). Benzimidazole-2-
carboxylic acid (H2BIC) represents a new kind of bis-
(chelating) bridging ligand and is less well explored than
oxalate and its derivatives. Several complexes constructed
from H2BIC molecules have been investigated, and they
exhibit low-dimensional structural features, such as mono-
nuclear, discrete six-membered rings and a two-dimensional
honeycomb network containing bowl-shaped voids (Dutta &
Satapathi, 1981; Rettig et al., 1999; Saczewski et al., 2006;
Zheng et al., 2011). In this work, we present the structures and
supramolecular assembly via hydrogen bonds of two new
Comment
The design and construction of coordination architectures
with unprecedented topologies have attracted considerable
attention over recent decades (Moulton & Zaworotko, 2001;
Roesky & Andruh, 2003). Discrete coordination assemblies
are linked through numerous weak interactions, such as
hydrogen bonds and ꢁ–ꢁ stacking, thereby resulting in higher-
dimensional supramolecular networks with multiple structural
m346 # 2011 International Union of Crystallography
doi:10.1107/S0108270111041837
Acta Cryst. (2011). C67, m346–m350

metal-organic compounds
complexes with HBIC ligands (HBIC is benzimidazole-2-car-
boxylate), namely, trans-bis(1H-benzimidazole-2-carboxylato-
ꢀ2N3,O)bis(ethanol-ꢀO)cadmium(II), (I), and trans-bis(1H-
benzimidazole-ꢀN3)bis(1H-benzimidazole-2-carboxylato-ꢀ2N3,O)-
nickel(II), (II). Both possess similar mononuclear structures
and one-dimensional hydrogen-bonding chains, but different
hydrogen bonds involving the group on the axial sites result in
quite different higher-dimensional networks.
However, further investigation indicates that these one-
dimensional chains are arranged in a quite different manner
through the linkage of intermolecular attractions, thereby
resulting in quite different supramolecular frameworks,
mainly due to the difference in the apical ligand of the metal
centres.
In compound (I), two ligated ethanol molecules act as
hydrogen-bond donors to form two hydrogen bonds with
carboxylate O atoms (O1 and O3) of HBIC ligands from
adjacent one-dimensional chains. The angle between the
ethanol O—H group and the equatorial plane is 81ꢁ and this
orientation of the hydrogen-bond donor favours the formation
of a ring. Thus, intermolecular O5—H5ꢀ ꢀ ꢀO3v and O6—
H6ꢀ ꢀ ꢀO1vi hydrogen bonds [symmetry codes: (v) x + 1, y, z;
(vi) x ꢂ 1, y, z] between adjacent mononuclear building units,
which generate R22(8) rings, serve to further link the one-
dimensional chains into an extended two-dimensional supra-
molecular layer, which runs along the ab plane (Fig. 4). In the
structure of (I), all potential strong hydrogen-bonding sites
are involved in the formation of hydrogen bonds in the two-
dimensional supramolecular network.
The molecule of complex (I) consists of one CdII ion, two
HBIC anions and two ligated ethanol molecules (Fig. 1), while
in complex (II), the asymmetric unit only contains half an NiII
ion, one HBIC anion and one benzimidazole molecule, as the
NiII ion lies on a crystallographic inversion centre (Fig. 2). (I)
and (II) are mononuclear complexes, in which the metal
centre displays a distorted octahedral coordination geometry
completed by two N atoms and two O atoms from two
bidentate chelating HBIC ligands in the equatorial plane, and
two donors from the different co-ligands in axial sites [O
atoms from two ethanol molecules in (I) and N atoms from
two benzimidazole molecules in (II)]. Selected bond lengths
and angles for the title compounds are listed in Tables 1 and 3;
the M—O and M—N bond distances [M = Cd in (I) and Ni in
(II)] are in the normal ranges (Sarma et al., 2009; Yang & Wu,
2009). In (I), two trans-oriented HBIC ligands in equatorial
positions are almost coplanar, with a dihedral angle between
the Cd1/N1/O1 and Cd1/N3/O3 planes of 9.97ꢁ. The two
ligated ethanol molecules occupy the axial sites and the axial
O5—Cd1—O6 angle [179.94 (19)ꢁ] deviates only slightly from
180ꢁ.
In compound (II), benzimidazole molecules occupying the
axial sites also act as hydrogen-bond donors to generate N4—
H4ꢀ ꢀ ꢀO1vii hydrogen bonds [symmetry code: (vii) ꢂx + 2, y + 12,
1
2
ꢂz + ] with carboxylate O atoms (O2) of HBIC anions.
Although the angle between the benzimidazole N—H group
and the equatorial plane is 45ꢁ and the orientation of the
hydrogen-bond donor in (II) is not suitable for the formation
of a hydrogen-bond ring, these hydrogen-bond interaction
sites cannot be restrained in a two-dimensional layer, thereby
resulting in a three-dimensional supramolecular network
(Fig. 5).
In the title compounds, pairs of N—Hꢀ ꢀ ꢀO hydrogen bonds
are formed between pairs of HBIC anions from adjacent
mononuclear building blocks [for (I): N2—H2ꢀ ꢀ ꢀO4ii and
N4—H4ꢀ ꢀ ꢀO2iii, symmetry codes: (ii) x + 1, y ꢂ 1, z; (iii) x ꢂ 1,
y + 1, z; for (II): N2—H2ꢀ ꢀ ꢀO2iv, symmetry code: (iv) ꢂx + 1,
ꢂy, ꢂz], which yield centrosymmetric R22(10) rings. Thus, the
connection of these hydrogen bonds leads to similar one-
dimensional chain-like structures in both complexes (Fig. 3).
Figure 1
The molecular structure of (I), showing the atom-numbering scheme.
Displacement ellipsoids are drawn at the 30% probability level. All H
atoms are drawn as spheres of arbitrary radii.
Figure 2
The molecular structure of (II), with displacement ellipsoids drawn at the
30% probability level. [Symmetry code: (i) ꢂx + 2, ꢂy, ꢂz.]
ꢃ
Acta Cryst. (2011). C67, m346–m350
Fan et al.
[Cd(C8H5N2O2)2(C2H6O)2] and [Ni(C8H5N2O2)2(C7H6N2)2] m347

metal-organic compounds
Figure 3
(a) A packing diagram of (I), showing a one-dimensional chain formed by pairs of intermolecular hydrogen bonds (dashed lines). (b) A packing diagram
of (II), showing a one-dimensional chain. Dashed lines represent N—Hꢀ ꢀ ꢀO interactions.
The topological analysis approach was employed to better
describe the structural characteristics of (II). The topology of
this three-dimensional supramolecular framework can be
simplified by considering the NiII coordination units as six-
connected nodes and the intermolecular hydrogen bonds as
two-connected linkers between these nodes. As a result, a
three-dimensional network structure of 412.63-pcu topology is
formed.
IR spectra of the two compounds show characteristic
absorptions for the carboxylate stretching vibrations. The
characteristic bands of carboxylate groups are seen in the
range 1648–1520 cmꢂ1 for asymmetric stretching and 1490–
1458 cmꢂ1 for symmetric stretching (Zheng et al., 2011). The
absence of strong absorption peaks around 1700 cmꢂ1 indi-
cates that all carboxyl groups (–COOH) are deprotonated.
Moreover, a strong and broad absorption band at 3587 cmꢂ1 is
assigned to the ꢂ(O—H) vibration of ethanol molecules in
complex (I).
In summary, two new complexes were constructed from the
reaction between various metal salts and H2BIC molecules
with different co-ligands. They show a similar mononuclear
structure, where the metal ions reside in a distorted octahedral
coordination environment and in which two bidentate che-
lating HBIC anions occupy equatorial positions. However,
intermolecular hydrogen bonds link discrete coordination
units to form different supramolecular networks.
Figure 4
Figure 5
A packing diagram of (I), showing the two-dimensional layer-like
structure along the ab plane. Dashed lines represent hydrogen-bonding
interactions.
A packing diagram of (II), showing the three-dimensional supra-
molecular network formed by intermolecular hydrogen bonds (dashed
lines).
ꢃ
m348 Fan et al. [Cd(C8H5N2O2)2(C2H6O)2] and [Ni(C8H5N2O2)2(C7H6N2)2]
Acta Cryst. (2011). C67, m346–m350

metal-organic compounds
Table 2
Hydrogen-bond geometry (A, ) for (I).
Experimental
ꢁ
˚
For the synthesis of complex (I), benzimidazole-2-carboxylic acid
(H2BIC, 16.2 mg, 0.10 mmol) was dissolved in water (5 ml) and the
pH was adjusted to about 8 with NaOH solution. A solution of
Cd(ClO4)2ꢀ6H2O (41.9 mg, 0.10 mmol) in ethanol (5 ml) was then
layered on the aqueous H2BIC solution. The system was left for about
two months at room temperature and colourless block-shaped crys-
tals of (I) were obtained by filtration (yield 56%). IR (KBr pellet, ꢂ,
cmꢂ1): 3587 (s), 3100 (s), 1648 (s), 1582 (w), 1520 (s), 1484 (m), 1458
(s), 1391 (m), 1331 (s), 1212 (w), 1147 (w), 1018 (s), 994 (w), 948 (w),
911 (w), 857 (m), 819 (m), 757 (s), 631 (w), 593 (w), 547 (w), 436 (w).
For the preparation of (II), a mixture of NiCl2ꢀ6H2O (23.8 mg,
0.10 mmol), H2BIC (16.2 mg, 0.10 mmol) and benzimidazole
(11.8 mg, 0.10 mmol) in H2O–C2H5OH (3:1v/v, 4 ml) was sealed in a
sample bottle reactor (10 ml) and heated at 383 K under autogenous
pressure for 48 h. After the sample had been cooled to room
temperature at a rate of 5 K hꢂ1, block-shaped pale-purple crystals of
(II) were collected (yield 68%). IR (KBr pellet, ꢂ, cmꢂ1): 3098 (s),
1627 (s), 1614 (s), 1523 (m), 1490 (m), 1464 (s), 1391 (s), 1372 (w),
1343 (s), 1302 (w), 1273 (w), 1145 (w), 1023 (m), 966 (w), 914 (w), 858
(w), 823 (m), 766 (w), 743 (s), 637 (w), 597 (w), 433 (w).
D—Hꢀ ꢀ ꢀA
D—H
Hꢀ ꢀ ꢀA
Dꢀ ꢀ ꢀA
D—Hꢀ ꢀ ꢀA
N2—H2ꢀ ꢀ ꢀO4i
0.86
0.86
0.85
0.85
1.94
1.94
1.91
1.85
2.743 (6)
2.761 (6)
2.678 (6)
2.678 (6)
155
158
150
164
N4—H4Aꢀ ꢀ ꢀO2ii
O5—H5Aꢀ ꢀ ꢀO3iii
O6—H6Aꢀ ꢀ ꢀO1iv
Symmetry codes: (i) x þ 1; y ꢂ 1; z; (ii) x ꢂ 1; y þ 1; z; (iii) x þ 1; y; z; (iv) x ꢂ 1; y; z.
Table 3
Selected geometric parameters (A, ) for (II).
ꢁ
˚
Ni1—N1
Ni1—N3
2.0492 (17)
2.1181 (18)
Ni1—O1
2.0915 (14)
N1—Ni1—O1i
N1—Ni1—N3
99.52 (6)
89.17 (7)
O1—Ni1—N3
O1—Ni1—N3i
91.52 (7)
88.48 (7)
Symmetry code: (i) ꢂx þ 2; ꢂy; ꢂz.
Table 4
Hydrogen-bond geometry (A, ) for (II).
ꢁ
˚
D—Hꢀ ꢀ ꢀA
D—H
Hꢀ ꢀ ꢀA
Dꢀ ꢀ ꢀA
D—Hꢀ ꢀ ꢀA
Compound (I)
N4—H4Aꢀ ꢀ ꢀO1ii
N4—H4Aꢀ ꢀ ꢀO2ii
N2—H2ꢀ ꢀ ꢀO2iii
0.86
0.86
0.86
2.56
2.25
1.91
3.111 (2)
3.030 (3)
2.753 (2)
123
150
167
Crystal data
[Cd(C8H5N2O2)2(C2H6O)2]
Mr = 526.82
Triclinic, P1
ꢅ = 78.54 (3)ꢁ
V = 1081.7 (4) A
Z = 2
Mo Kꢃ radiation
ꢆ = 1.05 mmꢂ1
T = 298 K
0.35 ꢄ 0.28 ꢄ 0.22 mm
3
˚
1
2
1
2
Symmetry codes: (ii) ꢂx þ 2; y þ ; ꢂz þ ; (iii) ꢂx þ 1; ꢂy; ꢂz.
˚
a = 5.4761 (11) A
˚
b = 10.477 (2) A
˚
c = 19.896 (4) A
Compound (II)
ꢃ = 75.31 (3)ꢁ
ꢄ = 88.67 (3)ꢁ
Crystal data
3
˚
V = 1419.5 (5) A
Z = 2
[Ni(C8H5N2O2)2(C7H6N2)2]
Mr = 617.27
Data collection
Bruker SMART APEXII CCD
area-detector diffractometer
Absorption correction: multi-scan
(SADABS; Bruker, 2002)
5344 measured reflections
3804 independent reflections
3228 reflections with I > 2ꢇ(I)
Rint = 0.021
Monoclinic, P21=c
Mo Kꢃ radiation
ꢆ = 0.74 mmꢂ1
T = 298 K
0.42 ꢄ 0.35 ꢄ 0.26 mm
˚
a = 10.321 (2) A
˚
b = 12.923 (3) A
˚
c = 11.495 (2) A
ꢄ = 112.21 (3)ꢁ
Tmin = 0.709, Tmax = 0.801
Refinement
Data collection
R[F2 > 2ꢇ(F2)] = 0.056
wR(F2) = 0.161
S = 1.17
3804 reflections
270 parameters
12 restraints
H-atom parameteꢂrs3 constrained
Bruker SMART APEXII CCD
area-detector diffractometer
Absorption correction: multi-scan
(SADABS; Bruker, 2002)
7496 measured reflections
2787 independent reflections
2374 reflections with I > 2ꢇ(I)
Rint = 0.022
˚
Áꢈmax = 0.93 e A
ꢂ3
˚
Áꢈmin = ꢂ1.26 e A
Tmin = 0.748, Tmax = 0.832
Refinement
R[F2 > 2ꢇ(F2)] = 0.035
wR(F2) = 0.096
S = 1.09
2787 reflections
184 parameters
6 restraints
H-atom parameteꢂrs3 constrained
Table 1
Selected geometric parameters (A, ) for (I).
ꢁ
˚
˚
Áꢈmax = 0.79 e A
ꢂ3
˚
Áꢈmin = ꢂ0.48 e A
Cd1—N1
Cd1—N3
Cd1—O1
2.254 (5)
2.265 (5)
2.317 (4)
Cd1—O3
Cd1—O5
Cd1—O6
2.327 (4)
2.354 (5)
2.372 (5)
A SIMU instruction (SHELXL97; Sheldrick, 2008) was used for
several C atoms with large displacement parameters in the refinement
of both structures. The H atoms of the ethanol molecules were
located in difference Fourier maps and the others were placed in
calculated positions and refined as riding atoms, with isotropic
displacement parameters [C—H = 0.97 (methyl), 0.96 (methylene)
N1—Cd1—N3
N1—Cd1—O1
N3—Cd1—O1
N1—Cd1—O3
N3—Cd1—O3
O1—Cd1—O3
N1—Cd1—O5
N3—Cd1—O5
177.57 (17)
74.26 (16)
105.53 (16)
105.98 (16)
74.21 (15)
179.45 (15)
93.64 (18)
88.78 (18)
O1—Cd1—O5
O3—Cd1—O5
N1—Cd1—O6
N3—Cd1—O6
O1—Cd1—O6
O3—Cd1—O6
O5—Cd1—O6
89.37 (17)
91.10 (17)
86.32 (18)
91.26 (17)
90.58 (17)
88.95 (17)
179.94 (19)
˚
˚
or 0.93 A (aromatic) and N—H = 0.86 A; Uiso(H) = 1.2Ueq(C),
1.2Ueq(N) or 1.5Ueq(O)].
ꢃ
Acta Cryst. (2011). C67, m346–m350
Fan et al.
[Cd(C8H5N2O2)2(C2H6O)2] and [Ni(C8H5N2O2)2(C7H6N2)2] m349

metal-organic compounds
Dutta, R. L. & Satapathi, S. K. (1981). J. Inorg. Nucl. Chem. 43, 1533–
1539.
Jiang, J. J., Li, L., Yang, T., Kuang, D. B., Wang, W. & Su, C. Y. (2009). Chem.
Commun. pp. 2387–2389.
Jiang, J. J., Zheng, S. R., Liu, Y., Pan, M., Wang, W. & Su, C. Y. (2008). Inorg.
Chem. 47, 10692–10699.
Kitaura, R., Seki, K., Akiyama, G. & Kitagawa, S. (2003). Angew. Chem. Int.
Ed. 42, 428–431.
For both compounds, data collection: APEX2 (Bruker, 2004); cell
refinement: SAINT (Bruker, 2004); data reduction: SAINT;
program(s) used to solve structure: SHELXS97 (Sheldrick, 2008);
program(s) used to refine structure: SHELXL97 (Sheldrick, 2008);
molecular graphics: XP in SHELXTL (Bruker, 2004); software used
to prepare material for publication: SHELXL97.
Madalan, A. M., Avarvari, N. & Andruh, M. (2006). Cryst. Growth Des. 6,
1671–1675.
Mota, A. J., Dieguez, A. R., Palacios, M. A., Herrera, J. M., Luneau, D. &
Colacio, E. (2010). Inorg. Chem. 49, 8986–8996.
Moulton, B. & Zaworotko, M. J. (2001). Chem. Rev. 101, 1629–1658.
Rettig, S. J., Storr, A. & Trotter, T. (1999). Can. J. Chem. 77, 434–438.
Roesky, H. W. & Andruh, M. (2003). Coord. Chem. Rev. 236, 91–119.
Ruiz, R., Faus, J., Lloret, F., Julve, M. & Journaux, Y. (1999). Coord. Chem.
Rev. 193, 1069–1117.
The authors gratefully acknowledge financial support from
the National Natural Science Foundation of China (grant Nos.
20771040 and 21003053), the Ministry of Science and Tech-
nology of China (grant No. 10C26214412704) and Guangdong
Science and Technology Department (grant No. 2010B0903-
00031).
Saczewski, F., Dziemidowicz-Borys, E., Bednarski, P. J., Gruenert, R., Gdaniec,
M. & Tabin, P. (2006). J. Inorg. Biochem. 100, 1389–1398.
Sarma, D., Ramanujachary, K. V., Lofland, S. E., Magdaleno, T. & Natarajan, S.
(2009). Inorg. Chem. 48, 11660–11676.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Train, C., Gheorghe, R., Krstic, V., Chamoreau, L. M., Ovanesyan, N. S.,
Rikken, G. L. J. A., Gruselle, M. & Verdaguer, M. (2008). Nat. Mater. 7, 729–
734.
Xu, H. B., Wang, Z. M., Liu, T. & Gao, S. (2007). Inorg. Chem. 46, 3089–
3096.
Yang, P. & Wu, J.-Z. (2009). Acta Cryst. C65, m4–m6.
Zhang, J. Y., Cheng, A. L., Yue, Q., Sun, W. W. & Gao, E. Q. (2008). Chem.
Commun. pp. 847–849.
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: QS3005). Services for accessing these data are
described at the back of the journal.
References
Bruker (2002). SADABS. Version 2.10. Bruker AXS Inc., Madison, Wisconsin,
USA.
Bruker (2004). APEX2. Version 6.12. Bruker AXS Inc., Madison, Wisconsin,
USA.
Colacio, E., Aouryaghal, H., Mota, A. J., Cano, J., Sillanp, R. & Dieguez, A. R.
(2009). CrystEngComm, 11, 2054–2064.
Zhang, J. Y., Ma, Y., Cheng, A. L., Yue, Q., Sun, Q. & Gao, E. Q. (2008). Dalton
Trans. pp. 2061–2066.
Custelcean, R., Moyer, B. A., Bryantsev, V. S. & Hay, B. P. (2006). Cryst.
Growth Des. 6, 555–563.
Zheng, S. R., Cai, S. L., Fan, J., Xiao, T. T. & Zhang, W. G. (2011). Inorg. Chem.
Commun. 14, 818–821.
ꢃ
m350 Fan et al. [Cd(C8H5N2O2)2(C2H6O)2] and [Ni(C8H5N2O2)2(C7H6N2)2]
Acta Cryst. (2011). C67, m346–m350