Syntheses, characterizations and crystal structures of four zinc(II) and cadmium(II) complexes constructed by ligand bearing poly-coordination atoms

Article abstract of DOI:10.1016/j.ica.2010.04.037

Treatment of 3-(4-carboxyphenylhydrazono)pentane-2,4-dione (HL) with transition metal ions afforded four novel complexes, [Zn(L)(μ₂- OOCCH₃)(H₂O)]_n (1), [Zn(L)₂(MeOH) ₄] (2), {[Cd₄(η²-L) ₄(μ₂-η²-L)₄(H ₂O)₄(MeOH)₂]·MeOH) (3) and [Cd(n ²-L)(μ₂-η²-OOCCH₃)(H ₂O)₂]_n (4). Their crystal structures have been characterized by single-crystal X-ray crystallography. In polymer 1, the acetate anions bridge the Zn(II) ions forming an infinite one-dimensional (1-D) chain with L^- units acting as monodentate ligands in the side chain. In mononuclear complex 2, two L^- ligands act as monodentate fashion to coordinate to the Zn(II) ion. In its solid-state structure, [Zn(L) ₂(MeOH)₄] groups are joined together by hydrogen bonds forming a three-dimensional (3-D) supramolecular network. In tetranuclear complex 3, four Cd(II) ions are linked by four μ₂- η²-L^- ligands, and chelated by another four L ^- ligands, respectively. In polymer 4, the acetate anions bridge the Cd(II) ions leading to a 1-D chain containing chelating L^- units in the side chain.

Full text of DOI:10.1016/j.ica.2010.04.037

Inorganica Chimica Acta 363 (2010) 2616–2623
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Inorganica Chimica Acta
journal homepage: www.elsevier.com/locate/ica
Syntheses, characterizations and crystal structures of four zinc(II) and
cadmium(II) complexes constructed by ligand bearing poly-coordination atoms
*
Zifeng Li, Guangjian Mei, Haifang Zhang, Gang Li , Wenyue Wang, Zongpei Zhang
Department of Chemistry, Zhengzhou University, Henan 450052, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 18 June 2009
Received in revised form 18 April 2010
Accepted 25 April 2010
Available online 5 May 2010
Treatment of 3-(4-carboxyphenylhydrazono)pentane-2,4-dione (HL) with transition metal ions afforded
four novel complexes, [Zn(L)(
(H2O)4(MeOH)2]ꢀMeOH} (3) and [Cd(
l
2-OOCCH3)(H2O)]n (1), [Zn(L)2(MeOH)4] (2), {[Cd4(
g -g
2-L)4(l2 2-L)4-
g
2-L)(l2 2-OOCCH3)(H2O)2]n (4). Their crystal structures have been
-g
characterized by single-crystal X-ray crystallography. In polymer 1, the acetate anions bridge the Zn(II)
ions forming an infinite one-dimensional (1-D) chain with Lꢁ units acting as monodentate ligands in
the side chain. In mononuclear complex 2, two Lꢁ ligands act as monodentate fashion to coordinate to
the Zn(II) ion. In its solid-state structure, [Zn(L)2(MeOH)4] groups are joined together by hydrogen bonds
forming a three-dimensional (3-D) supramolecular network. In tetranuclear complex 3, four Cd(II) ions
Keywords:
Coordination polymers
Crystal structures
Anion effect
are linked by four l2-g
2-Lꢁ ligands, and chelated by another four Lꢁ ligands, respectively. In polymer
4, the acetate anions bridge the Cd(II) ions leading to a 1-D chain containing chelating Lꢁ units in the side
chain.
Ó 2010 Elsevier B.V. All rights reserved.
1. Introduction
related complexes [28–30]. (3) As for hydrazone unit, it obviously
has strong coordination ability due to the existence of two N do-
Recently, considerable efforts have been devoted to design var-
ious ligands to construct coordination frameworks with tunable
properties [1–10]. People found that the geometry of ligating
atoms within a polynucleating ligand, the flexibility of the ligand
backbone, and the additional functional groups of the ligands all
play important roles in directing the structural outcome of the
resulting complex [11–20].
In the view of ligand design, compound 3-(4-carboxy-
phenylhydrazono)pentane-2,4-diketone (HL) is a very useful li-
gand. This compound contains three coordination units: carboxyl-
ate, hydrazono and b-diketone groups. Thus the compound should
have potential strong coordination ability. The reasons are as fol-
lows: (1) for carboxylate group, they usually adopt various coordi-
nation modes as terminal monodentate, chelating to one metal
center, bridging bidentate in a syn–syn, syn–anti, anti–anti configu-
ration to two metal centers and bridging tridentate to two metal
centers, etc. Moreover, hydrogen bonds are likely to be formed
among the carboxylate compounds providing additional support-
ing force for supramolecular system [21–27]. (2) For chelating
group b-diketone, as a constituent of polydentate ligands, it has
been increasingly encountered in the context of metallo-supramo-
lecular chemistry and widely used in coordination chemistry. Re-
cently, several groups have reviewed the diketone ligands and
nors. However, up to now, reported complexes bearing HL ligand
are still very limited [31–33]. It is to be pointed out that the re-
ported complexes with HL ligand have only been characterized
by elemental analysis and IR spectra, etc. There are no crystal data
for these complexes yet.
These considerations have prompted us to further study the
reaction of HL with other metal ions. We hope to obtain a series
of new complexes with novel structures and desired properties.
In this paper, the syntheses and crystal structures of four Zn(II)
and Cd(II) complexes (Scheme 1), namely [Zn(L)(
(H2O)]n (1), [Zn(L)2(MeOH)4] (2), {[Cd4(
2-L)4(l2
2-OOCCH3)(H2O)2]n (4)
l
-g
2-OOCCH3)-
g
2-L)4(H2O)4-
(MeOH)2]ꢀMeOH} (3) and [Cd(
g -g
2-L)(l2
are presented.
2. Results and discussion
2.1. Synthesis
From synthesis process of complexes 1–4, it is to be found that
utilization of different metal salts directs the structural outcome of
the resulting complex. When we use the metal nitrate salts,
Zn(NO3)2 or Cd(NO3)2, to react with NaL in solution, the mononu-
clear complex 2 or tetranuclear complex 3 have been produced.
When metal acetate salts, Zn(OAc)2 or Cd(OAc)2, react with NaL
in solution, two coordination polymers 1 and 4 can be obtained.
* Corresponding author.
E-mail address: gangli@zzu.edu.cn (G. Li).
0020-1693/$ - see front matter Ó 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2010.04.037

Z. Li et al. / Inorganica Chimica Acta 363 (2010) 2616–2623
2617
Zn(OAc) , MeOH
2
[Zn(L)(μ -OOCCH )(H O)]n
(1)
(2)
(3)
2
3
2
Zn(NO ) , MeOH
3 2
[Zn(L) (MeOH) ]
O
2
4
H
N
NaOOC
N C
+
Cd(NO ) , MeOH
O
3 2
2
2
.
{[Cd (η -L) (μ -η -L) (H O) (MeOH) ] MeOH}
2
4
4
4
2
4
2
Cd(OAc) , MeOH
2
2
NaL
[Cd (μ -L)(μ -η -OOCCH )(H O) ]n
2
2
3
2
2
(4)
Scheme 1.
Obviously, the anion effect of metal salts is significant for the prep-
aration of different structural complexes.
Another interesting feature of the complexes is the carboxylato
coordination mode of the ligand Lꢁ. In complexes 1–4, Lꢁ coordi-
nates as a terminal monodentate ligand (in complexes 1 and 2),
or as chelating ligand (in complexes 3 and 4), or as bridging triden-
tate ligand (in complex 3). It is worth noticing that only the car-
boxylato group of the ligand Lꢁ takes part in the coordination to
central metal ion. This is largely different from that in the reported
complexes bearing Lꢁ units [31,32]. As shown in Scheme 2, the
chelating b-diketone group (A) [32] or oxygen of carbonyl group
and nitrogen of hydrazono unit of the ligand Lꢁ (B) [33] join in
the coordination to metal ion. This is may be due to the utilization
of NaL to react with metal ions in our reaction. The sodium salt of
ligand is in favor of the coordination ability of carboxylate group.
The 1H NMR spectra exhibit signals at d = 14.42, 7.43–7.91, 2.51
and 2.45 ppm (for 1), 14.44, 7.45–7.90, 2.50 and 2.41 ppm (for 2),
14.49, 7.40–7.88, 2.52 and 2.45 ppm (for 3) and 14.51, 7.46–7.93,
2.57 and 2.48 ppm (for 4), which are similar to those of the free li-
gand HL of d = 14.58, 7.48–8.06, 2.59 and 2.51 ppm [31].
2.2. The molecular structure of crystalline [Zn(L)(l2-OOCCH3)(H2O)]n
(1)
Single-crystal structural determination reveals that polymer 1
crystallizes in the monoclinic space group P2(1)/c with the compo-
sition of neutral asymmetric unit [Zn(L)(
sumes an infinite1-D chain.
l2-OAc)(H2O)] and as-
As illustrated in Fig. 1, each Zn(II) atom is four-coordinated by
two oxygen atoms from two acetate ions, one oxygen atom from
one water molecule, and one oxygen atom from carboxylate group
Fig. 1. Molecular structure of [Zn(L)(l2-CH3COO)(H2O)]n (1) (H atoms omitted for
clarity).
of ligand Lꢁ to form a slightly distorted tetrahedron. The distances
of Zn–O are in the range of 1.961(4)–2.005(4) Å, are close to those
in previous carboxylate polymer {[Zn(FcCOO)2(bpt)]ꢀ2.5H2O}n
O
O
O
O
O
N
_
_
M1
N
OH
HO
O
N
(Fc = (g g
5-C5H5)Fe( 5-C5H4); bpt = N,N0-bis(3-pyridylmethyl)thio-
N
urea) [34] (Zn–O 1.946–1.977 Å). The bond angles around the cen-
tral Zn(II) ion vary from 92.85° to 123.13°. Each acetate anion acts
as bidentate ligand bridging the Zn(II) ions to form a 1-D chain, in
which the intrachain distances between metallic cations are
4.397 Å for Zn1ꢀ ꢀ ꢀZn1A.
A (M1 = Cu2+, Co2+, Ni2+
)
32
Within the same ligand Lꢁ, the dihedral angle between the phe-
nyl ring and carboxylate plane is 4.2°, which is significantly nar-
rower than the 14.7° in the corresponding free ligand HL [31].
The nitrogen–nitrogen bond of the complex is very similar to
(1.303(5) Å) that found in the crystal structure of the free HL
(1.307(3) Å). The C–O bond lengths of the carboxylate group of 1
are longer [C3–O3 1.267(6), C3–O4 1.237(6) Å] than those in the
free ligand [C–O 1.209 to 1.214 Å]. The C–O bond lengths of the
O
_
_
O
N
N
O
O
M2
H2O
B (M2 = Zn2+, Co2+, Ni2+, Cd2+, Mn2+
)
33
pentane-2,4-dione fragment of
1 [C11–O2 1.227(6), C12–O1
1.201(6) Å] are near to those in the free ligand [C–O 1.220(3) to
1.213(3) Å].
Scheme 2.

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Z. Li et al. / Inorganica Chimica Acta 363 (2010) 2616–2623
Fig. 2. Crystal packing view from the a-axis of [Zn(L)(l2-CH3COO)(H2O)]n (1).
In the solid state structure of 1, linear [Zn(L)(
l
2-OOCCH3)(-
bonds forming a one-dimensional ladder-like structure, then the
ladder-like chains pack each other through the van der Waals
interactions forming the 3-D supramolecular structure.
H2O)]n chains are linked by intermolecular hydrogen bonds form-
ing a 2-D sheet. It can be seen from Fig. 2, there are two kinds of
intermolecular hydrogen bonds. One is between O unit of the dike-
tone group from one [Zn(L)(
one coordination water molecule from neighboring [Zn(L)(l2
OOCCH3)(H2O)]n. The other originates from CH of the methyl group
from one [Zn(L)(
2-OOCCH3)(H2O)]n chain with O from the OAcꢁ
group of neighboring [Zn(L)( 2-OOCCH3)(H2O)]n unit. Thus, above
H-bond interactions together with van der Waals forces represents
the main contribution for the stabilization of the crystal packing
(Fig. 2).
l2-OOCCH3)(H2O)]n chain and OH of
2.4. The molecular structure of crystalline {[Cd4(g - -
2-L)4(l2 g2
L)4(H2O)4(MeOH)2]ꢀMeOH} (3)
-
l
X-ray diffraction analysis reveals that compound 3 crystallizes
l
ꢀ
in the space group P1. The structure of 3 is made up of a tetranu-
clear array of [Cd4(g -g
2-L)4(l2 2-L)4(H2O)4(MeOH)2] unit and a crys-
tallization methanol molecule. The ORTEP plot showing the
structural unit of 3 is illustrated in Fig. 4.
In the compound 3, the four Lꢁ ligands indicate two kinds of
coordination conformation: chelating and bridging tridentate fash-
ions. The four Cd(II) ions are bridged by four bridging tridentate Lꢁ
2.3. The molecular structure of crystalline [Zn(L)2(MeOH)4] (2)
X-ray diffraction analysis of compound 2 shows that it crystal-
ligands leading to a tetranuclear core [Cd4(l2-g
2-L)4]. The geome-
ꢀ
lizes in the space group P1. An ORTEP drawing of the structure with
tries around Cd1 and Cd2 are slightly different. Both Cd1 and Cd2
are seven-coordinated. For Cd1, five oxygen atoms from three Lꢁ li-
gands occupy the equatorial plane, and two oxygen atoms from
water and methanol molecules respectively occupy the axial posi-
tions, forming pentagonal bipyramid geometry. For Cd2, five oxy-
gen atoms from three Lꢁ ligands locate the equatorial plane; two
oxygen atoms from respective water and another Lꢁ ligand occupy
the axial positions to form pentagonal bipyramid geometry as well.
The bond lengths and bond angles around Cd1 and Cd2 are very
similar. The dihedral angle between the planes Cd1–Cd2–O16–
O11 (the mean deviation from the plane is 0.0567 Å) and Cd1A–
O12A–Cd1–O12 (the mean deviation from the plane is 0.0000 Å)
is 95.7°. The Cd1ꢀ ꢀ ꢀCd2 and Cd1ꢀ ꢀ ꢀCd1A distances are 3.794 and
3.915 Å, respectively. These distances are far shorter than that of
the reported complex built up by bipyridine-based bridges
{[Cd(o-O2CC6H4COFc)2(bpe)(MeOH)2]ꢀ2H2O}n (bpe = 1,2-bis(4-pyr-
idyl)ethene) (Cdꢀ ꢀ ꢀCd 14.047 Å) built up by bipyridine-based
bridges [35].
selected atoms labeling scheme is shown in Fig. 3.
Each Zn(II) is coordinated by six oxygen atoms forming a octa-
hedron geometry, in which four oxygen atoms from four coordi-
nated methanol molecules occupy the equatorial plane, and two
oxygen atom from two Lꢁ ligands locate at the axial position. The
distances of Zn–O are in the range of 2.016–2.162 Å (the average
Zn–O distance being 2.109 Å). These distances are slightly longer
than those in some ferrocene-based carboxylate complexes, for
example [Zn4(l2-FcCOO)6(l4-O)] (Zn–O: 1.837–2.001 Å) and
{[Zn(FcCOO)2(bpt)]ꢀ2.5H2O}n (Zn–O: 1.946–1.977) [34]. The angles
around the central Zn(II) ion are in the range of 89.00°–180°. In the
pentane-2,4-diketone fragment, the distances of O3–C9 and O4–
C11 are 1.226(3) and 1.226(2) Å, respectively, which are close to
those of complex 1. The distance of N–N being 1.308 Å is also close
to that found in the free HL ligand [31].
There are two kinds of hydrogen bonds in the compound 2. One
is intramolecular hydrogen bond [N1–H1ꢀ ꢀ ꢀO3 1.90 Å, 132.9°]. The
other is arising from the interaction of OH of the coordination
methanol molecule with O of one dione unit of the ligand Lꢁ. Thus,
these [Zn(L)2(MeOH)4] units are linked by intermolecular hydrogen
Interestingly, there exist aromatic p–p stacking interactions of
the neighboring benzene rings of the different Lꢁ ligands. The dihe-
dral between phenyl rings C2–C6 (the mean deviation from the

Z. Li et al. / Inorganica Chimica Acta 363 (2010) 2616–2623
2619
Fig. 3. Molecular structure of [Zn(L)2(MeOH)4] (2) (H atoms omitted for clarity).
Fig. 4. Molecular structure of {[Cd4(
g
2-L)4(l2
-
g
2-L)4(H2O)4(MeOH)2]ꢀMeOH} (3) (H atoms and solvent molecule omitted for clarity).
plane is 0.0048 Å) and C38A–C43A (the mean deviation from the
plane is 0.0049 Å) is 2.5° with the distance between the two rings
being 3.562 Å. The dihedral between other two phenyl rings C26–
C31 (the mean deviation from the plane is 0.0025 Å) and C13A–
C19A (the mean deviation from the plane is 0.0082 Å) is 8.8° with
the distance between the two rings being 3.612 Å.
Each Cd(II) atom is seven-coordinated, and is in a single-cap tri-
angular prism environment with three oxygen atoms O3, O4 and
O3A from two l2-g
2-OOCCH3 units, two oxygen atoms O1 and
O4 from one chelating L and two oxygen atoms O5 and O6 from
two water molecules (Fig. 6). Selected geometrical parameters
are listed in Table 1.
The bond distances and bond angles within the Lꢁ ligand of
complex 3 are unexceptional and close to those in complexes 1
and 2.
The Cd–O distances range from 2.232(6) to 2.554(6) Å, which
compares with 2.269(4) Å in the polymer [Cd(O2CC6H4{C(O)Fc-
o})2(bpe)(MeOH)2]ꢀ2H2O}n [35]. The angles around the Cd1 are in
the range of 53.1°–174.8°. The Cd1ꢀ ꢀ ꢀCd1A separation of 4.433 Å
is slightly longer than that in complex 3.
2.5. The molecular structure of crystalline [Cd(g - -
2-L)(l2 g2
OOCCH3)(H2O)2]n (4)
The bond distances and bond angles within the Lꢁ ligand of
complex 4 are unexceptional and close to those in complexes 1,
2 and 3.
The structure determination of 4 reveals that each OAcꢁ anion
acts as a tridentate fashion bridging the central Cd(II) ions forming
a 1-D chain. This molecule crystallizes in the space group P2(1)/n.
An ORTEP drawing of the chain structure with atom labeling
scheme is shown in Fig. 5.
Like complex 2, both the intramolecular and intermolecular
hydrogen bonds contribute to the stabilization of the complex 4.
The H-bond within the same ligand Lꢁ is between NH unit and
O8 [N1–H1ꢀ ꢀ ꢀO8 1.95 Å, 131.5°]. The intermolecular hydrogen

2620
Z. Li et al. / Inorganica Chimica Acta 363 (2010) 2616–2623
Fig. 5. 1-D chain structure of [Cd(
g
2-L)(l2
-
g
2-CH3COO)(H2O)2]n (4) (H atoms omitted for clarity).
3. Conclusions
By reacting of the organic ligand NaL with metal ions under
mild conditions, four crystalline products have been successfully
prepared. The X-ray diffraction results indicate that the Lꢁ ligands
in our complexes indicate interesting carboxylato coordination
mode. In particular, complex 3 shows novel tetranuclear structure.
The IR data are consistent with the X-ray analysis results.
4. Experimental
4.1. General materials and instruments
All reagents were got from commercial sources and used with-
out further purification.
3-(4-Carboxyphenylhydrazono)pentane-2,4-dione is prepared
according to reference procedure [36]. Its sodium salt was pre-
pared with sodium methoxide.
Fig. 6. The coordination conformation of Cd1 in complex 4.
Infrared spectra were recorded on a Nicolet NEXUS 470-FTIR
spectrophotometer as KBr pellets in the 400–4000 cmꢁ1 region.
Elemental analyses (EAs) were carried out on a FLASH EA1112 Ele-
bonds originate OH units of the coordination water molecules with
mental Analyzer. 1H NMR spectra were recorded at room temper-
ature with a Bruker DPX 400 spectrometer.
O of OAcꢁ anion and carboxylate unit of Lꢁ of adjacent [Cd(g2
-
L)(l2
-
g
2-OOCCH3)(H2O)2]n chain [O5–H5Aꢀ ꢀ ꢀO1A 1.92 Å, 175.6°;
O5–H1 Wꢀ ꢀ ꢀO4D 2.09 Å, 149°]. Thus, in the solid state structure
of 4, linear [Cd(
g
2-L)(l2
-
g
2-OOCCH3)(H2O)2]n chains are linked by
4.2. Syntheses of the complex [Zn(L)(l2-CH3COO)(H2O)]n (1)
intermolecular hydrogen bonds forming a 2-D sheet. These 2-D
sheets pack each other through the van der Waals interactions
forming the 3-D supramolecular structure (Fig. 7).
Zn(OAc)2ꢀ2H2O (0.011 g, 0.05 mmol) and NaL (0.025 g,
0.1 mmol) in methanol solution (5 ml) was stirred for 30 min.
The resulting mixture was filtered and the filtrate was allowed to
stand at room temperature. After 1 month, good quality yellow sin-
gle crystals of 1 were obtained. Crystals of 1 are stable in the air.
Yield: 68% based on Zn. Anal. Calc. (%) for C14H15O7N2Zn: C,
43.19; H, 4.11; N, 7.20. Found: C, 43.22; H, 4.15; N, 7.15%. IR
(cmꢁ1, KBr): 3400(s), 3249(s), 2924(m), 1655(s), 1630(s), 1598(s),
1547(s), 1505(w), 1464(w), 1406(w), 1372(m), 1279(m), 1196(s),
1162(s), 1099(m), 1055(w), 1025(m), 990(m), 939(s), 870(s),
839(s), 788(s), 699(s), 613(s). 1H NMR (400 MHz, CDCl3): d = 2.45
(s, 3 H, CH3CO), 2.51 (s, 3 H, CH3CO), 7.43 (s, 2 H, Ar–H), 7.91 (s,
2 H, Ar–H), 14.42 (s, 1 H, NH).
2.6. IR spectroscopy
According to Refs. [31–33,36], the characteristic IR bands of HL
are the existence of an NH vibration around 3260 cmꢁ1 and a
m
(C@N) frequency between 1587 and 1606 cmꢁ1, which can be
found in the four complexes (3249 and 1547–1629 cmꢁ1for 1;
3247 and 1547–1630 cmꢁ1 for 2; 3250 and 1595–1630 cmꢁ1 for
3; 3396 and 1522–1627 cmꢁ1 for 4). The strong bands at 1623
and 1553 cmꢁ1 for 1, 1456 and 1549 cmꢁ1 for 2, 1661 and
1382 cmꢁ1 for 3 and 1669 and 1411 cmꢁ1 for 4 are assigned to
m
as(COOꢁ) and s(COOꢁ) vibrations, while those at 1324 and
m
788 cmꢁ1 (1), 1324 and 788 cmꢁ1 (2), 1318 and 799 cmꢁ1 (3),
1320 and 782 cmꢁ1 (4) are due to
(CO–CH3) and (Ar–H) vibra-
4.3. Syntheses of the complex [Zn(L)2(MeOH)4] (2)
m
m
tions, respectively. In conclusion, these IR data are consistent with
the crystal data of the four complexes.
The synthesis of 2 was similar to that of 1 except that
Zn(NO3)2ꢀ6H2O (0.0149 g, 0.05 mmol) was used instead of

Z. Li et al. / Inorganica Chimica Acta 363 (2010) 2616–2623
2621
Found: C, 48.46; H, 5.23; N, 8.13%. IR (cmꢁ1, KBr): 3247(m),
2929(w), 1655(s), 1629(w), 1598(s), 1547(m), 1505(s), 1465(w),
1406(s), 1372(s), 1324(s), 1280(w), 1197(s), 1163(s), 939(s),
870(m), 840(m), 788(s), 699(m), 665(w), 614(w), 544(m),
436(m). 1H NMR (400 MHz, CDCl3): d = 2.41 (s, 3 H, CH3CO), 2.50
(s, 3 H, CH3CO), 7.45 (s, 2 H, Ar–H), 7.90 (s, 2 H, Ar–H), 14.44 (s,
1 H, NH).
Table 1
Selected bond distances (Å) and angles (°) for 1, 2, 3 and 4.a
1
Zn(1)–O(3)
Zn(1)–O(6)#1
N(1)–N(2)
C(3)–O(3)
C(11)–O(2)
O(3)–Zn(1)–O(5)
O(5)–Zn(1)–O(6)#1
O(5)–Zn(1)–O(7)
1.961(4)
Zn(1)–O(5)
1.974(4)
2.005(4)
1.993(4)
1.237(6)
1.201(6)
116.75(16)
102.84(17)
92.85(15)
1.993(4)
Zn(1)–O(7)
1.303(5)
1.267(6)
O(6)–Zn(1)#2
C(3)–O(4)
1.227(6)
C(12)–O(1)
123.13(17)
103.06(15)
114.44(17)
O(3)–Zn(1)–O(6)#1
O(3)–Zn(1)–O(7)
O(6)#1–Zn(1)–O(7)
4.4. Syntheses of the complex {[Cd4(l2-L)4(l2- -
g2
L)4(H2O)4(MeOH)2]ꢀMeOH} (3)
2
Zn(1)–O(1)#1
Zn(1)–O(5)
Zn(1)–O(6)
N(1)–N(2)
2.0158(12)
2.1480(16)
2.1622(15)
1.308(2)
Zn(1)–O(1)
Zn(1)–O(5)#1
Zn(1)–O(6)#1
2.0158(12)
2.1481(16)
2.1622(15)
NaL (0.025 g, 0.1 mmol) was dissolved in methanol 3 ml. The
solution was added slowly dropwise to solution of
a
Cd(NO3)2ꢀ4H2O (0.0155 g, 0.05 mmol) in 3 ml methanol. The
resulting mixture was filtered, and the filtrate was allowed to
stand at room temperature. Good quality yellow crystals for 3 were
obtained after 1 month. Crystals of 3 are stable in the air. Yield:
62% based on Cd. Anal. Calc. (%) for C100H112N16O40Cd4: C, 45.67;
O(1)#1–Zn(1)–O(1)
O(1)–Zn(1)–O(5)
O(1)–Zn(1)–O(5)#1
O(1)#1–Zn(1)–O(6)
O(5)–Zn(1)–O(6)
O(1)#1–Zn(1)–O(6)#1
O(5)–Zn(1)–O(6)#1
O(6)–Zn(1)–O(6)#1
180.00(10)
89.61(6)
90.39(6)
89.00(6)
89.94(6)
91.00(6)
90.06(6)
179.999(1)
O(1)#1–Zn(1)–O(5)
O(1)#1–Zn(1)–O(5)#1
O(5)–Zn(1)–O(5)#1
O(1)–Zn(1)–O(6)
O(5)#1–Zn(1)–O(6)
O(1)–Zn(1)–O(6)#1
O(5)#1–Zn(1)–O(6)#1
90.39(6)
89.61(6)
180.0
91.00(6)
90.06(6)
89.00(6)
89.94(6)
H, 4.26; N, 8.52. Found: C, 45.25; H, 3.85; N, 8.13%. IR (cmꢁ1
,
KBr): 3422(m), 1661(s), 1630(w), 1595(m), 1519(s), 1382(s),
1318(m), 1182(s), 1162(m), 935(w), 838(m), 780(m), 6679(w),
441(m). 1H NMR (400 MHz, CDCl3): d = 2.45 (s, 3 H, CH3CO), 2.52
(s, 3 H, CH3CO), 7.40 (s, 2 H, Ar–H), 7.88 (s, 2 H, Ar–H), 14.49 (s,
1 H, NH).
3
Cd(1)–O(14)
Cd(1)–O(19)
Cd(1)–O(12)#1
Cd(1)–O(12)
Cd(2)–O(17)
Cd(2)–O(15)
Cd(2)–O(16)
N(1)–N(2)
N(5)–N(6)
O(14)–Cd(1)–O(16)
O(16)–Cd(1)–O(19)
O(16)–Cd(1)–O(11)
O(14)–Cd(1)–O(12)#1
O(19)–Cd(1)–O(12)#1
O(10)–Cd(2)–O(17)
O(17)–Cd(2)–O(18)
O(17)–Cd(2)–O(15)
O(10)–Cd(2)–O(9)
O(18)–Cd(2)–O(9)
O(10)–Cd(2)–O(16)
O(18)–Cd(2)–O(16)
O(9)–Cd(2)–O(16)
O(17)–Cd(2)–O(11)
O(15)–Cd(2)–O(11)
O(16)–Cd(2)–O(11)
2.309(2)
2.310(2)
2.406(3)
2.473(2)
2.286(3)
2.309(3)
2.468(2)
1.296(4)
1.305(4)
89.76(8)
98.47(8)
78.60(8)
98.14(8)
164.63(8)
91.43(9)
170.54(9)
93.56(10)
54.56(9)
95.99(9)
165.50(9)
86.63(9)
139.84(8)
87.10(9)
126.99(8)
73.00(8)
Cd(1)–O(16)
Cd(1)–O(11)
Cd(1)–O(13)
Cd(2)–O(10)
Cd(2)–O(18)
Cd(2)–O(9)
Cd(2)–O(11)
N(3)–N(4)
2.315(3)
2.348(2)
2.418(2)
2.279(2)
2.294(3)
2.427(3)
2.498(2)
1.298(4)
1.321(4)
84.66(8)
161.33(9)
82.70(8)
96.66(9)
97.68(8)
90.10(9)
140.26(9)
91.23(10)
92.50(10)
85.83(9)
89.59(9)
54.02(9)
92.61(8)
83.50(9)
147.16(7)
4.5. Syntheses of the complex [Cd(g -g
2-L)(l2 2-OOCCH3)(H2O)2]n (4)
N(7)–N(8)
The synthesis of 4 was similar to that of 3 except that
Cd(OAc)2ꢀ2H2O (0.0134 g, 0.05 mmol) was used instead of
Cd(NO3)2ꢀ4H2O. Good quality yellow single crystals for 4 were ob-
tained after 1 month. Crystals of 4 are stable in the air. Yield: 57%
based on Cd. Anal. Calc. (%) for C14H18O8N2Cd: C, 37.00; H, 3.96; N,
6.17. Found: C, 37.13; H, 3.99; N, 6.12%. Yield: 57%. IR (cmꢁ1, KBr):
3396(s), 2929(m), 1926(m), 1669(s), 1627(m), 1597(s), 1522(s),
1411(s), 1356(w), 1320(s), 1294(w), 1273(s), 1201(m), 1185(w),
1166(s), 1026(m), 937(m), 871(m), 859(s), 840(s), 782(s), 685(s),
660(m), 617(s), 453(s). 1H NMR (400 MHz, CDCl3): d = 2.48 (s, 3
H, CH3CO), 2.57 (s, 3 H, CH3CO), 7.46 (s, 2 H, Ar–H), 7.93 (s, 2 H,
Ar–H), 14.51 (s, 1 H, NH).
O(14)–Cd(1)–O(19)
O(14)–Cd(1)–O(11)
O(19)–Cd(1)–O(11)
O(16)–Cd(1)–O(12)#1
O(11)–Cd(1)–O(12)#1
O(10)–Cd(2)–O(18)
O(10)–Cd(2)–O(15)
O(18)–Cd(2)–O(15)
O(17)–Cd(2)–O(9)
O(15)–Cd(2)–O(9)
O(17)–Cd(2)–O(16)
O(15)–Cd(2)–O(16)
O(10)–Cd(2)–O(11)
O(18)–Cd(2)–O(11)
O(9)–Cd(2)–O(11)
4.6. X-ray crystallography
4
Cd(1)–O(3)#1
Cd(1)–O(1)
Cd(1)–O(5)
Cd(1)–O(3)
N(1)–N(2)
O(3)#1–Cd(1)–O(6)
O(6)–Cd(1)–O(1)
O(6)–Cd(1)–O(4)
O(3)#1–Cd(1)–O(5)
O(1)–Cd(1)–O(5)
O(3)#1–Cd(1)–O(2)
O(1)–Cd(1)–O(2)
O(5)–Cd(1)–O(2)
O(6)–Cd(1)–O(3)
O(4)–Cd(1)–O(3)
O(2)–Cd(1)–O(3)
2.232(6)
2.327(6)
2.367(7)
2.554(6)
1.307(11)
97.3(2)
121.6(3)
95.6(2)
78.7(2)
82.1(2)
84.8(2)
54.3(2)
95.8(2)
76.3(2)
53.1(2)
104.9(2)
Cd(1)–O(6)
Cd(1)–O(4)
Cd(1)–O(2)
O(3)–Cd(1)#2
2.262(7)
2.359(6)
2.460(6)
2.232(6)
The crystallographic data for complexes 1–4 are listed in Table
2. All measurements were made on a Bruker Smart 1000 diffrac-
tometer with
a
graphite-monochromated Mo Ka radiation
(k = 0.71073 Å). Single crystals of 1 (0.45 ꢂ 0.24 ꢂ 0.23 mm), of
2 (0.44 ꢂ 0.36 ꢂ 0.22 mm) and of 3 (0.38 ꢂ 0.24 ꢂ 0.21 mm), of
4 (0.43 ꢂ 0.15 ꢂ 0.21 mm) were selected and mounted on a glass
fiber. All data were collected at a temperature of 293(2) K using
O(3)#1–Cd(1)–O(1)
O(3)#1–Cd(1)–O(4)
O(1)–Cd(1)–O(4)
O(6)–Cd(1)–O(5)
O(4)–Cd(1)–O(5)
O(6)–Cd(1)–O(2)
O(4)–Cd(1)–O(2)
O(3)#1–Cd(1)–O(3)
O(1)–Cd(1)–O(3)
O(5)–Cd(1)–O(3)
132.4(2)
91.9(2)
108.7(2)
79.9(3)
168.9(2)
174.8(3)
89.0 (2)
142.6(3)
77.9(2)
the
x
ꢁ 2h scan technique and corrected for Lorenz-polarization
effects. A correction for secondary extinction was applied. The
four structures were solved by direct methods and expanded
using the Fourier technique. The non-hydrogen atoms were re-
fined with anisotropic thermal parameters. Hydrogen atoms were
included but not refined. The final cycle of full-matrix least
squares refinement was based on 6819 observed reflections
134.1(2)
a
Symmetry transformations used to generate equivalent atoms. For complex 1:
#1 = x, ꢁy + 3/2, z ꢁ 1/2; #2 = x, ꢁy + 3/2, z + 1/2. For complex 2: #1 = ꢁx, ꢁy + 3, ꢁz.
For complex 3: #1 = ꢁx + 3, ꢁy, ꢁz. For complex 4: #1 = x ꢁ 1/2, ꢁy + 1/2, z ꢁ 1/2;
#2 = x + 1/2, ꢁy + 1/2, z + 1/2.
and 2678 variable parameters for
1 [Rint = 0.0313], 5930
observed reflections and 2942 variable parameters for
2
[Rint = 0.0171], 14 662 observed reflections and 10 195 variable
parameters for 3 [Rint = 0.0411], and 9248 observed reflections
and 2964 variable parameters for 4 [Rint = 0.0817]. All calcula-
tions were performed using the SHELX-97 [37] crystallographic
software package. The selected bond lengths and bond angles
are listed in Table 1.
Zn(OAc)2ꢀ2H2O. Good quality white crystals for 2 were obtained
after 2 weeks. Crystals of 2 are stable in the air. Yield: 73.0% based
on Zn. Anal. Calc. (%) for C28H38N4O12Zn: C, 48.88; H, 5.57; N, 8.14.

2622
Z. Li et al. / Inorganica Chimica Acta 363 (2010) 2616–2623
Fig. 7. Crystal packing view from the c-axis of [Cd(
g
2-L)(l2
-g
2-CH3COO)(H2O)2]n (4).
Table 2
The crystallographic data for complexes 1, 2, 3 and 4.
Complex
1
2
3
4
Formula
Formula weight
T (K)
C
14H15N2O7Zn
C28H38N4O12Zn
687.99
293(2)
C100H112N16O40Cd4
2627.66
291(2)
C14H18O8N2Cd
454.70
291(2)
388.65
291(2)
Crystal system
Space group
Crystal size (mm3)
a (Å)
b (Å)
c (Å)
monoclinic
P2(1)/c
triclinic
P1
triclinic
P1
monoclinic
P2(1)/n
ꢀ
ꢀ
0.45 ꢂ 0.24 ꢂ 0.23
7.9200(16)
24.480(5)
8.7400(17)
90.00
107.25(3)
90.00
1618.3(6)
1.595
0.44 ꢂ 0.36 ꢂ 0.22
7.9778(11)
8.1168(11)
14.183(2)
75.734(2)
83.992(2)
63.110(2)
793.81(19)
1.439
0.38 ꢂ 0.24 ꢂ 0.21
11.880(2)
15.820(3)
16.410(3)
114.54(3)
90.33(3)
96.19(3)
2784.8(10)
1.567
0.43 ꢂ 0.15 ꢂ 0.21
7.4915(5)
29.088(2)
8.5568(5)
90.00
113.315(4)
90.00
1712.4(2)
1.764
a
(°)
b (°)
c
(°)
V (Å3)
Dc (Mg mꢁ3
)
Z
l
4
1
1
4
(mmꢁ1
)
1.556
0.841
0.846
1.320
F(0 0 0)
796
360
1336
912
Reflections collected/unique
6819/2678,
Rint = 0.0313
2678/0/220
R1 = 0.0672,
wR2 = 0.1911
R1 = 0.0798,
wR2 = 0.2175
1.093
5930/2942,
Rint = 0.0171
2942/0/209
R1 = 0.0316,
wR2 = 0.0861
R1 = 0.0357,
wR2 = 0.0894
1.048
14662/10195,
Rint = 0.0411
10195/5/723
R1 = 0.0494,
wR2 = 0.0972
R1 = 0.0937,
wR2 = 0.1110
1.005
9248/2964,
Rint = 0.0817
2964/0/234
R1 = 0.0722,
wR2 = 0.1747
R1 = 0.1093,
wR2 = 0.1895
1.042
Data/restraints/parameters
Final R indices [I > 2
R indices (all data)
r(I)]
Goodness-of-fit (GOF) on F2
free of charge from The Cambridge Crystallographic Data Centre
via www.ccdc.cam.ac.uk/data_request/cif. Supplementary data
associated with this article can be found, in the online version, at
doi:10.1016/j.ica.2010.04.037.
Acknowledgments
We gratefully acknowledge the financial support by the Na-
tional Natural Science Foundation of China (20501017 and
J0830412) and by the Key Project of Chinese Ministry of Education
(207067) and the Project Sponsored by the Scientific Research
Foundation for the Returned Overseas Chinese Scholars of Chinese
Ministry of Education.
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