Crystal structure and fluorescence of supramolecular compound [Cd 3Cl6C6N2O8H 22]n

Article abstract of DOI:10.1134/S0036023611120333

A novel trinuclear supramolecular compound of [Cd₃Cl ₆C₆N₂O₈H₂₂]_n has been synthesized under alanine with cadmium chloride to the reaction in aqueous solution conditions, and characterized by elemental analyses, FT-IR spectroscopy, X-ray diffraction, DTA-TG. Its crystal structure was determined from single crystal X-ray diffraction. The title compound crystallizes in monoclinic system with space group P2₁/n. The crystal structure of the compound is characterized by forming a trinuclear 3D supramolecular structure with three cadmium(II) ions, six chloride ions, two molecules D, L-alanine in salt, two coordinated water molecules and two crystal water molecules. Cd(1) is distorted octahedrally coordinated with two oxygen atoms (from the adjacent amino acid and water molecule) and four chloride ions; Cd(2) is smaller extent distorted octahedrally coordinated with two oxygen atoms (from the adjacent amino acids) and four chloride ions. Cd(1) and Cd(2) connected by the bridge bonds of μ₂-Cl, μ₃-Cl and the carboxyl oxygen into ID chain structure, which further connected by hydrogen bonds to form 3D supramolecular network. Fluorescence test showed that the compound has a good photoluminescence property, respectively. Pleiades Publishing, Ltd., 2011.

Full text of DOI:10.1134/S0036023611120333

ISSN 0036ꢀ0236, Russian Journal of Inorganic Chemistry, 2011, Vol. 56, No. 12, pp. 1967–1971. © Pleiades Publishing, Ltd., 2011.
PHYSICAL METHODS
OF INVESTIGATION
Crystal Structure and Fluorescence of Supramolecular
1
Compound [Cd Cl C N O H ]
3
6 6
2
8
22 n
Ge Guo, Ruzhong Sun, and Yuanlin Dang
College of Chemistry and Pharmacy Engineering, Nanyang Normal University, Nanyang, Henan, 473061, China
eꢀmail: yuanlindang@yahoo.com.cn
Received September 20, 2010
Abstract—A novel trinuclear supramolecular compound of [Cd Cl C N O H22]n has been synthesized
3
6
6
2 8
under alanine with cadmium chloride to the reaction in aqueous solution conditions, and characterized by
elemental analyses, FTꢀIR spectroscopy, Xꢀray diffraction, DTAꢀTG. Its crystal structure was determined
from single crystal Xꢀray diffraction. The title compound crystallizes in monoclinic system with space group
P
2 /n. The crystal structure of the compound is characterized by forming a trinuclear 3D supramolecular
1
structure with three cadmium(II) ions, six chloride ions, two molecules D, Lꢀalanine in salt, two coordinated
water molecules and two crystal water molecules. Cd(1) is distorted octahedrally coordinated with two oxygen
atoms (from the adjacent amino acid and water molecule) and four chloride ions; Cd(2) is smaller extent disꢀ
torted octahedrally coordinated with two oxygen atoms (from the adjacent amino acids) and four chloride
ions. Cd(1) and Cd(2) connected by the bridge bonds of
μ
2ꢀCl, 3ꢀCl and the carboxyl oxygen into ID chain
μ
structure, which further connected by hydrogen bonds to form 3D supramolecular network. Fluorescence
test showed that the compound has a good photoluminescence property, respectively.
DOI: 10.1134/S0036023611120333
1
Cadmium is an important environmental and diffraction, DTGꢀTG and fluorescence spectra. Its
industrial toxins, it also is a very long halfꢀlife multiꢀ crystal structure was determined from single crystal
organ, multiꢀsystem poison [1, 2]. Amino acids are an Xꢀray diffraction, to our knowledge, the structure of
important component of biological organisms, it’s the the type not been reported.
basic unit of peptide and protein composition, it also
is the metabolic processes of biological organisms in
the basic materials, it has important physiological
functions. As we all know, we study the composition
and structure of complexes with the cadmium and the nine (Ala) (mass fraction
amino acid is benefit of the physiological role of
Equipment and conditions. C, H and N analyses
EXPERIMENTAL SECTION
Reagents. CdCl (mass fraction
≥
0.996), DL–alaꢀ
2
≥
0.998).
organism. Moreover, cadmium is one of the semiconꢀ were carried out with a Vario EL III CHNOS element
ductor materials, which compounds are mostly good analysis instrument. The IR analysis was conducted on
photoluminescence properties [3, 4]. The inorganicꢀ a Nicolet 5700 spectrometer (KBr discs). Thermal
organic supramolecular compound is a new material, characterization of the new compound was underꢀ
which has wide application areas of optical, catalytic, taken with a SDT Q600 V8.0 thermal analysis apparaꢀ
magnetic materials, conductors, semiconductors, tus (TGꢀDTG) that worked with a heating rate of
nonlinear optical materials and molecular recognition 10 K/min under a N2 atmosphere with a flow rate of
3
[
5–8]. To investigate the compounds of cadmium(II) 100 cm /min; Xꢀray diffraction (XRD) measurements
and amino acid form a supramolecular structure and were performed by a D/Maxꢀ3C diffractometer using
photoluminescence properties, the compound [2ꢀ(3ꢀ Cu radiation, 50 kV and 80 mA, at room temperaꢀ
[Cd Cl ] has been synꢀ ture, in air. The diffraction data of the structure analyꢀ
K
α
4+
4–
pyridy1)benzimidazoleH2]
⋅
2
8
sis was collected by a Bruker Smart Apexꢀll CCD difꢀ
fractometer using a graphite monochromatized Mo
radition ( = 0.071 073 nm), at room temperature.
thesized under been synthesized under hydrothermal
conditions in literature [9], and its structure and fluoꢀ
rescence properties have been studied. In this paper,
K
α
λ
Broker); CARY Eclipse fluorescence spectrophotomꢀ
eter (VARIAN), light flashingꢀtype is xenon lamp, its
we report
a
8
supramolecular compound of
has been synthesized under
22 n
[
Cd Cl C N O H ] (I)
3
6
6
2
–1
scanning speed of 12000 nm min . Excitation and
alanine with cadmium chloride to the reaction in
aqueous solution conditions at 323 K, and characterꢀ
ized by elemental analyses, FTꢀIR spectroscopy, Xꢀray
emission slits were 5.0 nm.
Synthesis. The title compound was synthesized
from a mixture of 1.8331 g of CdCl2 in 30 mL of H O,
2
1
The article is published in the original.
0.5934 g of Ala in 30 mL of H O, the CdCl2 and Ala in
2
1967

1968
GUO et al.
Table 1. Bond lengths [Å] and angles [deg] for
I
Cd(1)–O(1)
2.273(4)
2.321(4)
Cd(2)–Cl(1)#3
2.5880(15)
Cd(1)–O(2W)
Cd(2)–Cl(2)
2.6419(14)
Cd(1)–Cl(2)#1
2.8401(15)
2.301(4)
O(2)–C(2)#2
1.272(7)
Cd(2)–O(2)
O(2W)–H(2)
0.81(8)
O(1)Cd(1)O(2W)
O(1)Cd(1)Cl(2)
83.25(16)
103.44(11)
170.71(12)
82.79(13)
78.43(11)
87.01(12)
172.83(5)
88.05(5)
O(2)Cd(2)Cl(1)#3
O(2)Cd(2)Cl(2)
Cl(1)#1Cd(2)Cl(2)
O(2)Cd(2)Cl(2)#2
Cl(2)Cd(2)Cl(2)#2
Cd(1)Cl(2)Cd(2)
Cd(1)Cl(2)Cd(1)#1
Cd(2)Cl(2)Cd(1)#1
Cd(2)#4Cl(1)Cd(1)
C(2)#2O(2)Cd(2)
Cd(1)O(2W)H(1)
Cd(1)O(2W)H(2)
–
93.88(11)
86.68(11)
O(2W)Cd(1)Cl(2)
O(2W)Cd(1)Cl(1)
O(1)Cd(1)Cl(2)#1
O(2W)Cd(1)Cl(2)#1
Cl(3)Cd(1)Cl(2)#1
Cl(2)Cd(1)Cl(2)#1
Cl(1)Cd(1)Cl(2)#1
O(2)#2Cd(2)O(2)
O(2)#2Cd(2)Cl(1)#1
O(2)Cd(2)Cl(1)#1
O(2)#2Cd(2)Cl(1)#3
Note: Symmetry code: #1 –
84.84(5)
93.32(11)
180.00(6)
102.94(5)
91.95(5)
92.29(4)
80.36(4)
98.79(5)
180.0(2)
129.6(4)
93.88(11)
86.12(11)
86.12(11)
109(5)
112(5)
–
x
– 2, –
y, –
z
; #2 –
x
–1, –
y, –z; #3
x
+ 1,
y,
z; #4
x
– 1,
y,
z
. (CCDC number–CCDC 729398).
the molar ratio of 3 : 2. Ala solution will slowly add
drops of CdCl2 solution, constantly mixed at 323 K crystal with dimensions 0.12
Determination of crystal structure. A suitable single
0.10 0.08 mm was
×
×
about 8 h, and then vacuum evaporation. The resulting selected for the crystal structure measurements. The
columnar colorless crystals were collected and dried in Xꢀray diffraction intensities were recorded by a Bruker
air at ambient temperature. Analysis calculated for the ApexꢀII CCD diffractometer with graphite monoꢀ
title compound: C 9.00, H 2.75, N 3.50%; found: C chromatized Mo
K
radiation ( = 0.071073 nm), at a
λ
α
9
.09, H 2.56, N 3.42%.
temperature of 296(2) K. A total of 5203 reflection
10000
100
TG
80
60
40
20
0
8000
6000
4000
2000
0
DTG
300 400 500 600 700 800 900 1000
Temperature/K
10
20
30
40
, deg
50
60
70
2θ
Fig. 1. Xꢀray powder diffraction spectrum of
Cd Cl C N O H ]n.
Fig.
2.
Thermoꢀgravimetric
[Cd Cl C N O H ]n.
curve
of
[
3
6
6
2
8
22
3
6 6 2 8 22
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 56 No. 12 2011

CRYSTAL STRUCTURE AND FLUORESCENCE
and deg]
(D–H)
1969
Table 2. Hydrogen bonds for A [
D–H⋅⋅⋅A (Å)
Å
d
d
(H⋅⋅⋅A)
d
(D⋅⋅⋅A)
<(DHA)
N(1)–H(1A)⋅⋅⋅Cl(3)#5
N(1)–H(1B)⋅⋅⋅O(1W)#6
N(1)–H(1B)⋅⋅⋅Cl(1)#7
0.86
0.86
0.86
2.65
2.32
2.82
3.250(5)
3.005(7)
3.337(5)
128
137
120
Note: Symmetry code: #5 –x – 2, –y –1, –z; #6 –x – 3/2, y – 1/2, –z – 1/2; #7 x + 1/2, –y – 1/2, z – 1/2.
complexes, the adsorption bonds at 1624 and 1410 cm–1
,
intensities, of which 1889 were independent (Rint
=
<
0
2
.0292), were collected within the range 2.40 <
4.99 deg for the compound. All data were corrected
θ
assigned to the asymmetrical and symmetrical stretchꢀ
–
ing vibrations of COO in D, Lꢀalanine, are shifted to
and experience Lp absorption correction factor. Posiꢀ
tions of the hydrogen atoms attached to carbon and
nitrogen atoms were fixed at their ideal positions, and
those attached to water hydrogen atoms were not
located. All nonꢀhydrogen atoms were refined anisꢀ
tropically. The final cycle of refinement performed on
afforded residuals R1 = 0.0381 and wR2 = 0.1691. The
–1
1
619 and 1464 cm , respectively. The results indicate
that these carboxyl groups of the complexes are double
–1
coordination. (3) The band around 3444 cm is
attributed to the stretching vibration of –OH in the
–1
H O molecular. The band observed near 531 cm is
2
the wagging vibration of H O, which indicates that
2
H O molecular take part in coordination. (4) The
2
structures were solved using direct method and refined
2
complexes also exhibit some medium intensity bands
at the low wavelength range. For example, the bands
by fullꢀmatrix leastꢀsquares methods on
SHELXLꢀ97 program package [10, 11].
F
by using
–1
around 369 and 357 cm are assigned to the symmetꢀ
rical stretching vibration of Cd–O, and the peaks
–1
RESULTS AND DISCUSSION
around 283, 266, 260 cm are ascribed to the symmetꢀ
rical stretching vibration of Cd–Cl, which suggested
that the oxygen atoms and chlorine atoms also take
part in coordination.
The FTꢀIR spectrum of the pure D, Lꢀalanine and
the complexes are recorded from KBr tablet in the
–1
region of 100–4000 cm . Compared with that of the
pure Ala, the spectrum of the asꢀformed complexes
The Xꢀray powder diffraction pattern of the I comꢀ
displays several significant differences: (1) The pound obtained is shown in Fig. 1. It is neither the
adsorption peaks at 3086 and 2958 cm–1 are resulted same as CdCl2 or Ala, nor the simple superposition of
from the asymmetrical stretching vibration and the CdCl2 and Ala. This demonstrates that I is formed
+
from a reaction between CdCl2 and Ala.
symmetrical stretching vibration of NH3 ; however, as
to the complexes, these adsorption bands become
TGꢀDTG curves for the title compound ispreꢀ
broadened and are shifted to 3130 cm–1, which reveals sented in Fig. 2. It can be seen clearly from the massꢀ
the existence of strong hydrogen bonds between amino loss curve that three steps existed in the process of the
groups and H O. (2) As shown in the spectrum of the thermal decomposition for
I. The solid complex was
2
Cd
Cl
O
N
H
C
Fig. 3. Oneꢀdimensional chain of the complex for a.
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 56 No. 12 2011

1970
GUO et al.
stable below 360 K and started decomposition at this
point. The first massꢀloss took place in the range of
60 to 475 K, the second massꢀloss occurred in the
O1W
3
N1
C1
temperature range 508 to 643 K, and the third massꢀ
loss arose at 782 K. These results were well in accord
with those obtained by DTG curve. The first massꢀloss
was 9.19%, and the second massꢀloss was 17.12%.
According to the massꢀloss in each step, it was
assumed that the first massꢀloss peak was associated
with the loss of water, the second massꢀloss peak corꢀ
responded to the decomposition of Ala, and the third
massꢀloss peak represented the sublimation of cadꢀ
mium chloride. The first massꢀloss value was in agreeꢀ
ment with the theoretical dehydration value of 9.00%.
O2W
C3
Cl1
C2
Cd1
Cl2
Cl3
Cd
Cl
O
Cd2
N
H
O2
C
The main bond lengths and angles for title comꢀ
pound is listed in Table 1 and the details of hydrogen
bonds for title compound is listed in Table 2. The
asymmetric structure of the title compound consists of
Fig. 4. Asymmetric unit structure.
2
+
two Cd cation, one amino acid molecule and water
molecule as shown in Fig. 3. Figure 4 shows the oneꢀ
dimensional chain of the complex along the a axis.
Figure 5 shows the coordination environment of Cd
atoms. Unit cell composed of three cadmium(II) ions,
six chloride ions, two molecules Ala in salt, two coorꢀ
dinated water and two crystal water and formed 3D
supramolecular compound. Cd(l) is distorted octaheꢀ
drally coordinated with two oxygen atoms O(1) which
from the adjacent amino acid and O(2W) which from
water molecule, and four chloride ions (Cl(3) and
Cl(2)#l are in the axial position). The bond length is
Cd
Cl
O
N
H
C
2.5325(15) Å for Cd(1)–Cl(3) and 2.8401(15) Å for
Cd(1)–Cl(2)#l, the bond angle is 172.83(5)° for
Cl(3)Cd(l)Cl(2)#l. O(2W), O(1), Cl(1) and Cl(2) are
in the equatorial position, the shortest bond length is
2
.273(4) Å and the longest bond length of 2.6221(15) Å.
The equatorial plane diagonal atomic the largest angle
is 170.71(12)° for O(2W)Cd(1)Cl(2) and 155.11(10)
Fig.
5.
Molecular
Cd Cl C N O H ]n.
structure
of
complex
°
[
3
6
6 2 8 22
for O(1)Cd(1)Cl(1). Cd(2) is smaller extent distorted
octahedrally coordinated with two oxygen atoms of
O(2) and O(2)#2 which from the adjacent amino acids
and four chloride ions (Cl(2) and Cl(2)#2 are in the
axial position). The bond length is 2.6419(14) Å for
Cd(2)–Cl(2). Cl(1)#l, Cl(1)#3, O(2) and O(2)#2 are
in the equatorial position, the shortest bond length is
2.301(4) Å and the longest bond length of 2.5880(15) Å.
Cd(1) and Cd(2) are connected by the bridge bonds of
220
200
180
160
140
120
4
36
423
460
μ
2ꢀCl,
μ
3ꢀCl and formed quadrilateral shape. Cd(1)
and Cd(1)#1 are connected by the bridge bonds of
3ꢀCl(2)–Cl(2), Cl(2)#2 linked to form a new fourꢀ
μ
ring. Cl(2) is connected with Cd(1), Cd(2) and
Cd(1)#1 in the form of three bridges. The bonds
length of 2.5938(15) Å for Cd(1)–Cl(2), 2.6419(14) Å
for Cd(2)–Cl(2), 2.8401(15) Å for Cl(2)–Cd(1)#1.
The bonds angles 102.94(5)° for Cd(1)Cl(2)Cd(2),
4
00 410 420 430 440 450 460 470
Wavelength (nm)
91.95(5)° for Cd(1)Cl(2)Cd(1)#1, 92.29(4)° for
Cd(2)Cl(2)Cd(1)#1, while Cd(1) and Cd(2) through
the carboxyl oxygen O(1), O(2) the formation of carꢀ
boxylic bridge bond. The asymmetric unit connected
Fig. 6. Fluorescence spectra of compound
Cd Cl C N O H ]n.
[
by the bridge bonds of
μ
2ꢀCl, 3ꢀCl and the carboxyl
μ
3
6 6 2 8 22
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 56 No. 12 2011

CRYSTAL STRUCTURE AND FLUORESCENCE
1971
oxygen into 1D chain structure along the a axis, which
further connected by hydrogen bonds (N(1)–
H(1A)···Cl(3)#5, N(1)–H(1B)···O(1W)#6, N(1)–
H(1B)···Cl(1)#7) to form 3D supramolecular netꢀ
work, thereby increasing the stability of the title comꢀ
pound.
3. Mao Jiayuan, Fang Hongxin, Lu Jianmei, et al., Chin.
lnorg. Chem. 24 (7), 1046 (2008).
4. Feng Li, Tian Jinlei, Yan Shiping, et al., Sci. Natur.
Univ. Nankalensis 41 (1), 51 (2008).
5. Li Wei, Li Changhong, Yang Yingqun, et al., Chin.
Inorg. Chem. 24 (7), 1051 (2008).
Figure 6 is the title compound at room temperature
with 255 nm excitation fluorescence spectra, and we
can seen from the graph, the compound at 423, 436
and 460 nm have a relatively strong fluorescence emisꢀ
sion peak, and the fluorescence intensity in 436 nm is
greater than in the 423 and 460 nm, the causes need to
be further studied.
6. M. B. Zamman, M. D. Smith, D. M. Ciurtin, et al.,
Inorg. Chem. 41, 4895 (2002).
7. Li Wei, Li Changhong, Yang Yingqun, et al., Chin.
Inorg. Chem. 24 (8), 1360 (2008).
8. Li Jianding, Zhang Wu, Tao Ruojie, et al., Chem.
J. Chin. U. 29 (3), 453 (2008).
9. Guo Yingchen, Sun Ruzhong, Qiao Zhanping, et al.,
Chin. Inorg. Chem. 25 (8), 1447 (2009).
1
0. G. M. Sheldrick, SHELXL97. Program for Crystal
Structure Refinement (Univ. of Göttingen, Göttingen,
1997).
REFERENCES
1
. Peng Xiaojun, Du Jianjun, W. Fan Jiangli, et al., J. Am.
Chem. Soc. 129 (6), 1500 (2007).
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1. G. M. Sheldrick, SHELXL97. Program for Crystal
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RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 56 No. 12 2011