Two novel lanthanide coordination polymers: Synthesis, structures, fluorescence, and thermal properties

Article abstract of DOI:10.1080/15533174.2010.522537

Two novel 1-D chain lanthanide coordination polymers, {[Pr(μ ₂-L)₂(η²-NO₃)(CH ₃OH)(H₂O)₂]H₂O}n (1) and {[Ho(μ₂-L)₂(η²-NO₃)(CH ₃OH)(H₂O)]H₂O}_n (2) (HL = N-benzoyl-N'-(4-benzoxy)thiourea) have been prepared and characterized by IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. The fluorescence properties and themostabilities of the two polymers were determined as well. Copyright Taylor & Francis Group, LLC.

Full text of DOI:10.1080/15533174.2010.522537

Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 40:739–747, 2010
Copyright © Taylor & Francis Group, LLC
ISSN: 1553-3174 print / 1553-3182 online
DOI: 10.1080/15533174.2010.522537
Two Novel Lanthanide Coordination Polymers: Synthesis,
Structures, Fluorescence, and Thermal Properties
Zifeng Li, Kaiyue Zhu, Lihua Yan, and Gang Li
Department of Chemistry, Zhengzhou University, Zhengzhou, P. R. China
boxylate compound N-benzoyl-Nꢀ-(4-benzoxy)thiourea (HL)
in the references. In this contribution, we explore this type of
novel polymers containing both HL and lanthanide ions. We
utilized NaL to react with lanthanide ions to afford two novel
complexes {[Pr(µ2-L)2(η2-NO3)(CH3OH)(H2O)2]·H2O}n (1)
and {[Ho(µ2-L)2(η2-NO3)(CH3OH)(H2O)]·H2O}n (2), charac-
terized their single-crystal structures, and further studied their
fluorescent and thermal properties. The emission spectra of the
two complexes reflected that the ligands predominate the fluo-
rescence properties.
Two novel 1-D chain lanthanide coordination polymers,
{[Pr(µ2-L)2(η2-NO3)(CH3OH)(H2O)2]·H2O}n (1) and {[Ho(µ2-
L)2(η2-NO3)(CH3OH)(H2O)]·H2O}n (2) (HL = N-benzoyl-Nꢀ-(4-
benzoxy)thiourea) have been prepared and characterized by IR
spectroscopy, elemental analysis and single-crystal X-ray diffrac-
tion. The fluorescence properties and themostabilities of the two
polymers were determined as well.
Keywords coordination polymers, crystal structures, fluorescence
properties, thermal properties
O
S
OH
O
INTRODUCTION
The field of coordination polymers and metal–organic frame-
works has seen a tremendous expansion in research efforts over
the past several years.[1−9] As part of a study on the crystal en-
gineering of network solids, a series of coordination polymers
have been prepared using lanthanide salts and bridging ligands
derived from carboxylate[10−13] or pyridyl[14−17] or sulfonate[18]
molecules, and so on. Among various multidentate species,
compounds bearing carboxylate functions are often the most
preferred and widely studied ligands for generating stable lan-
thanide coordination polymers, mainly because of the versa-
tile ligating abilities of the –COO− moieties and the enhanced
affinity of these metal ions towards such O donors.[10−13] Thus,
people have used many kinds of carboxylate ligands to prepare
novel lanthanide coordination polymers.
N
H
N
H
HL
EXPERIMENTAL
General Materials and Instruments
All chemicals were of reagent grade quality obtained from
commercial sources and used without further purification. HL
was prepared according to the literature method.[19] Its sodium
salt was prepared by the reaction of it with sodium methoxide.
IR spectra were recorded on a Nicolet NEXUS 470-FTIR
spectrophotometer as KBr pellets in the 400–4000 cm−1 region.
Elemental analyses (C, H and N) were carried out on a FLASH
EA1112 elemental analyzer. Fluorescence spectrum of the three
complexes was characterized at room temperature by a F-4500
fluorescence spectrophotometer (240 nm/min). TG-DSC mea-
surements were performed by heating the crystalline sample
from 20 to 800◦C at a rate of 10◦C·min−1 in air on a Netzsch
STA 409PC differential thermal analyzer.
It is to be pointed out that there are no examples of lan-
thanide coordination polymers constructed from the organic car-
Received 13 January 2010; accepted 20 July 2010.
The authors gratefully acknowledge the financial support by the Na-
tional Natural Science Foundation of China (20501017 and J0830412),
by the Key Project of Chinese Ministry of Education (207067), by
the Scientific Research Foundation for the Returned Overseas Chinese
Scholars of Chinese Ministry of Education, by the Foundation for Uni-
versity Key Young Teacher by the Henan Educational Committee, and
by the Natural Science Foundation of Henan Educational Committee
(2007150040; 2009A150028).
Synthesis of [{Pr(µ2-L)4(η2-NO3) (CH3OH)
(H2O)2}·H2O]n (1)
Address correspondence to Gang Li, Department of Chemistry,
Zhengzhou University, Zhengzhou 450052, P. R. China. E-mail:
gangli@zzu.edu.cn
NaL (16.1 mg, 0.05 mmol) in 3 mL of methanol solu-
tion was added dropwise to a methanol solution (4 mL) of
739

740
Z. LI ET AL.
TABLE 1
The crystallographic data for complexes 1 and 2
Compound
1
2
Formula
Formula weight
T(K)
C63.5H54N10O25.5Pr2S4
1775.27
C31H27N5O13HoS2
906.63
293(2) K
Triclinc
291(2) K
Triclinc
Crystal system
Space group
Crystal size(mm3)
P-1
P-1
0.20 × 0.20 × 0.20
9.6062(19)
9.817(2)
0.20 × 0.16 × 0.16
˚
a(A)
9.835(2)
˚
b (A)
10.351(2)
18.781(2)
84.61(3)
84.43(3)
84.42(3)
˚
c (A)
21.220(4)
77.71(3)
80.65(3)
76.73(3)
1889.4(6)
1.560
α (◦)
β (◦)
γ (◦)
3
˚
V (A )
Dc (Mg m−3
Z
1887.1(7)
1.596
)
1
2
µ (mm−1
F(000)
)
1.467
891
2.274
902
Reflens collected/unique
18860 / 6631
R(int) = 0.0198
6631/0/481
R1 = 0.0344
wR2 = 0.1155
R1 = 0.0355
wR2 = 0.1165
1.205
19115/6641
R(int) = 0.1625
6641/0/459
R1 = 0.1520
wR2 = 0.3718
R1 = 0.1708
wR2 = 0.3897
1.223
Data/restraints/parameters
Fina R indices [I>2sigma(I)]
R indices (all data)
Goodness-of-fit on F2
Symmetry transformations used to generate equivalent atoms. For complex 1: #1 = −x+1,−y+1,−z; For
complex 2: #1 = −x+1,−y+1,−z+1; #2 = −x+2,−y+1,−z+1.
Pr(NO3)3·6H2O (43.5 mg, 0.1 mmol). The resulting colorless
mixture was allowed to stand at room temperature. Good qual-
ity colorless crystals of 1 were obtained after one month. Yield:
58.2%. Anal. calcd.(%) for C63.5H54O25.5N10S4Pr2: C, 42.96;
H, 3.09; N, 7.89; S, 7.23. Found: C, 42.86; H, 3.01; N, 8.06; S,
7.63. IR (cm−1, KBr): 3381 (m), 3284 (m), 3179 (s), 2364 (m),
1938 (w), 1603 (s), 1560 (m), 1404 (s), 1336 (s), 1257 (s), 1177
(s), 1103 (m), 1021 (w), 891 (s), 837 (m), 784 (s), 721 (s), 706
(s), 664 (w), 626 (m), 511 (s), 470 (w).
X-Ray Crystallography
Crystal data and experimental details for compounds 1 and
2 are contained in Table 1. All measurements were made on a
Rigaku SATURN-724 imaging plate area detector with graphite
monochromated Mo-Kα radiation (λ = 0.710 73 A). Colorless
˚
prismatic single crystals of 1 (0.20 × 0.20 × 0.20 mm) and of 2
(0.20 × 0.16 × 0.16 mm) were selected and mounted on a glass
fiber. All data were collected at a temperature of 291(2) K using
the ω-2θ scan technique and corrected for Lorenz-polarization
effects. A correction for secondary extinction was applied.
The two structures were solved by direct methods and ex-
panded using the Fourier technique. The non-hydrogen atoms
were refined with anisotropic thermal parameters. Hydrogen
atoms were included, but not refined. The final cycle of full-
matrix least squares refinement was based on 6631 observed
reflections and 481 variable parameters for 1 and 6641 observed
reflections and 459 variable parameters for 2. All calculations
were performed using the SHELX-97 crystallographic software
package.[20] Selected bond lengths and bond angles are listed in
Table 2.
Synthesis of {[Ho(µ2-L)2(η2-NO3)(CH3OH)(H2O)]·
H2O}n (2)
The complex 2 was prepared in a manner analogous to that
used to prepare 1. Reaction of Ho(NO3)3·6H2O with NaL gave
2 as colorless single crystals. Yield: 61%. Anal. calcd. (%) for
C62H54O26N10S4Ho2: C, 41.07; H, 3.00; N, 7.72; S, 7.07. Found:
C, 41.39; H, 3.26; N, 8.02; S, 7.62. IR (cm−1, KBr): 3361 (m),
3278 (m), 1604 (s), 1536 (s), 1409 (s), 1336 (s), 1257(w), 1177
(m), 1103 (m), 1070 (w), 891 (m), 838 (m), 783 (s), 722 (s), 663
(w), 622 (w), 561 (w), 511 (w).

LANTHANIDE COORDINATION POLYMERS
741
TABLE 2
a
˚
Selected bond distances (A) and angles (deg) for 1 and 2
1
Pr(1) O(24)#1
Pr(1) O(4)
2.406 (3)
2.449 (3)
Pr(1) O(3)
Pr(1) O(27)
2.421(3)
2.571(3)
Pr(1) O(20)
2.583 (4)
Pr(1) O(21)
2.652(4)
O(24)#1 Pr(1) O(2)
O(24)#1 Pr(1) O(26)
O(27) Pr(1) O(21)
O(2) Pr(1) O(3)
O(26) Pr(1) O(21)
O(27) Pr(1) O(25)
O(27) Pr(1) O(20)
O(26) Pr(1) O(27)
O(3) Pr(1) O(26)
O(24)#1 Pr(1) O(3)
O(4) Pr(1) O(21)
O(26) Pr(1) O(25)
O(2) Pr(1) O(25)
O(4) Pr(1) O(27)
O(2) Pr(1) O(26)
87.40 (11)
76.94 (14)
132.38 (13
78.58 (11)
65.90 (14)
126.88 (12)
138.76 (12)
133.66 (14)
134.76 (13)
141.64 (12)
73.00 (12)
68.20 (13)
70.57 (12)
73.29 (11)
138.68 (13)
O(24)#1 Pr(1) O(4)
O(4) Pr(1) O(25)
O(4) Pr(1) O(20)
O(25) Pr(1) O(21)
O(2) Pr(1) O(21)
O(3) Pr(1) O(25)
O(3) Pr(1) O(20)
O(2) Pr(1) O(27)
O(3) Pr(1) O(4)
O(20) Pr(1) O(21)
O(24)#1 Pr(1) O(21)
O(26) Pr(1) O(20)
O(2) Pr(1) O(20)
O(24)#1 Pr(1) O(27)
O(2) Pr(1) O(4)
91.82(10)
142.25(12)
120.61(12)
100.17(14)
125.18(11)
134.04(11)
73.84(12)
72.45(11)
79.95(10)
48.32(13)
142.21(13)
86.90(15)
80.23(12)
70.81(12)
143.93(11)
2
Ho(1) O(3)
Ho(1) O(7)
Ho(1) O(10)
Ho(1) O(2)#2
2.267 (8)
2.532 (10)
86.90 (15)
2.303 (8)
153.4 (3)
51.3 (3)
71.2 (3)
125.6 (3)
73.5 (3)
76.1 (3)
74.9 (3)
75.0 (3)
84.3 (3)
109.4 (3)
88.6 (3)
70.0 (3)
139.8 (3)
77.0 (3)
Ho(1) O(6)
Ho(1) O(5)#1
Ho(1) O(11)
80.23(12)
2.302(8)
2.394(9)
2.400(10)
85.1(3)
140.6(3)
75.5(3)
134.3(3)
126.8(3)
144.2(3)
76.4(3)
86.3(3)
92.1(3)
139.7(3)
135.4(3)
74.1(3)
Ho(1) O(9)
O(3) Ho(1) O(6)
O(9) Ho(1) O(7)
O(2)#2 Ho(1) O(7)
O(3) Ho(1) O(7)
O(2)#2 Ho(1) O(9)
O(3) Ho(1) O(9)
O(5)#1 Ho(1) O(11)
O(2)#2 Ho(1) O(10)
O(3) Ho(1) O(10)
O(3) Ho(1) O(2)#2
O(6) Ho(1) O(5)#1
O(5)#1 Ho(1) O(7)
O(11) Ho(1) O(9)
O(6) Ho(1) O(11)
O(3) Ho(1) O(5)#1
O(10) Ho(1) O(7)
O(6) Ho(1) O(7)
O(10) Ho(1) O(9)
O(6) Ho(1) O(9)
O(2)#2 Ho(1) O(11)
O(3) Ho(1) O(11)
O(6) Ho(1) O(10)
O(6) Ho(1) O(2)#2
O(5)#1 Ho(1) O(2)#2
O(11) Ho(1) O(7)
O(5)#1 Ho(1) O(9)
O(10) Ho(1) O(11)
O(5)#1 Ho(1) O(10)
70.4(3)
145.2(3)
RESULTS AND DISCUSSION
ing ligand link the central ion Pr(III) ions to form a 1D chain
(Figure 1).
Crystal Structure of [{Pr(µ2-L)4(η2-NO3)
(CH3OH)(H2O)2}·H2O]n (1)
There is only one crystallographically independent Pr(III)
ion in the crystal lattice. As shown in Figure 1, each nine-
coordinate Pr(III) ion is joined to the two oxygen atoms from
chelated η2-NO3, four oxygen atoms from four bridging µ2-
L, one oxygen atom from methanol molecule and two oxy-
gen atoms from two water molecules forming a distorted tr-
icapped trigonal prism coordination polyhedron (Figure 2).
X-ray diffraction analysis of compound 1 shows that it crys-
tallizes in the space group P1. Compound 1 contains an infinite
chain {Pr(µ2-L)4(η2-NO3)(CH3OH)(H2O)2}n, one crystalliza-
tion water molecules. It is a double-cross one-dimensional coor-
dination polymer, in which NO−3 anion as a bidentate chelating
ligand and the carboxylate group of L− as a bidentate bridg-
˚
The bond length of Pr-O is between 2.406(3) A and 2.652(4)

742
Z. LI ET AL.
FIG. 1. One-dimensional chain structure of polymer 1 (Hydrogen atoms and solvent molecules omitted for clarity).
A (the average bond length of Pr-O being 2.518(6) A). The O: 2.44(2)–2.67(3) A)[23], {NH4[Pr(OVA)4]}n (OVA = 2-
˚
˚
˚
Pr-O distances are within the range of those observed for hydroxy-3-methoxybenzoate) (Pr-O: 2.4088(15)–2.5717(14)
[24]
other Pr(III) complexes with oxygen donor ligands,[21−25] for A)
and {[Pr(pzdc)1.5(H2O)3]·0.5H2O}n, (pzdc = 2,5-
˚
[25]
˚
example in {[Pr(mptc)(H2O)4]·3H2O}n (H3mptc = 6-methyl- pyrazinedicarboxylate) (Pr-O: 2.434(3)-2.529(3) A).
The
2,3,5-pyridinetricarboxylic acid) (Pr-O: 2.389(2)–2.516(3) bond angles around Pr(III) change within the scope of 51.2(2)◦-
[21]
[Ln(HPPDA)(PPDA)(H2O)2]·2H2O (H2PPDA = (2,3- 152.7(3)◦. The intrachain distances between metallic cations
˚
A),
˚
f)-pyrazino(1,10)phenanthroline-2,3-dicarboxylic acid) (Pr-O: are 5.471 A for Pr1. . . Pr1A, which is largely shorter than that
2.440(3)–2.618(3) A),
[22]
˚
{[Pr(C2O4)(ClO4)(H2O)]·Cl}n (Pr- in the reported polymer {[Pr(mptc)(H2O)4]·3H2O}n (10.116
[21]
˚
A),
however, slightly longer than that in the polymer
[24]
˚
{NH4[Pr(OVA)4]}n (4.516 A).
Obviously, this is due to the
different coordination modes of the different carboxylate lig-
ands. The dihedral angles between the phenyl rings C2 C6 (the
˚
˚
˚
˚
mean deviation from the plane is 0.0097 A) and C9 C14 (the
mean deviation from the plane is 0.0071 A) or C16 C20 (the
mean deviation from the plane is 0.0036 A) and C24 C29 (the
mean deviation from the plane is 0.0097 A) in the same ligand
L− are 7.1◦ or 29.0◦, respectively.
In the solid-state structure, the 1-D chains pack each other
through the Van der Waals interactions. Figure 3 gives the crystal
packing structure of polymer 1.
Crystal Structure of {[Ho(␮2-L)2(␩2-NO3)
(CH3OH)(H2O)]·H2O}n (2)
X-ray diffraction analysis of compound 2 shows that it crys-
tallizes in the space group Pî as polymer 1. The structure of 2
is made up of a one-dimensional array of [Ho(η2-NO3)(H2O)2]
units bridged by µ2-L ligands. The ORTEP plot showing the
structural unit of 2 is illustrated in Figure 4.
FIG. 2. The coordination environment around the central Pr atom.

LANTHANIDE COORDINATION POLYMERS
743
FIG. 3. Crystal packing of 1 in the solid state.
The Ho (III) atoms are eight-coordinated by two oxygen
atoms from chelated η2-NO3, four oxygen atoms from four
bridging µ2-OOCC6H4N2C5O2 and two oxygen atoms from
one water and one methanol molecules. The coordination poly-
hedron is a slightly distorted bicapped trigonal prism (Figure 5).
˚
A for Ho1. . . Ho1B, respectively, which are consistent with that
of the polymer {NH4[Ho(OVA)4]}n (4.825 A).[24] The dihedral
˚
angles between the phenyl rings C2 C6 (the mean deviation
˚
˚
from the plane is 0.0145 A) and C9 C14 (the mean deviation
from the plane is 0.0301 A) or C16 C20 (the mean deviation
from the plane is 0.0036 A) and C24 C29 (the mean deviation
˚
˚
The bond length of Ho O is between 2.259(7) A and 2.561(9) A.
˚
˚
˚
−
◦
The average bond length of Ho O is 2.375(6) A. The Ho O dis-
from the plane is 0.0063 A) in the same ligand L are 26.0 or
165.8◦, respectively. These values can be compared to the cases
in polymer 1.
tances can be compared to those found in the reported Ho(III) co-
˚
ordination polymer {NH4[Ho(OVA)4]}n A (Ho O: 2.259(3)–
[24]
˚
In this complex, all the NO3− as a bidentate chelating lig-
and, the carboxylate group of L as a bidentate ligand bridging
central Ho(III) ions form a novel 1D chain coordination polymer
2.43(3) A).
The bond angle around Ho(III) changes within
the scope of 51.2(2)◦–152.7(3)◦. The intrachain distances be-
˚
tween metallic cations are 4.727 A for Ho1. . . Ho1A and 5.117
FIG. 4. Perspective view of polymer 2 with atom labeling scheme (H atoms omitted for clarity).

744
Z. LI ET AL.
(Figure 6). Furthermore, these chains are connected by the Van
der Waals interactions to construct three-dimensional networks
(Figure 7).
To the best of our knowledge, the reported Ho(III)
carboxylate-based coordination polymers are limited. Only
several examples can be found in the references. For
example, Czakis-Sulikowska and co-workers have re-
ported the synthesis and properties of a Ho(III) complex
{[Ho(4,4-bipy)(CCl2HCOO)3]·H2O}n with 4,4ꢀ-bipyridine and
dichloroacetates.[26] Cunha-Silva and co-workers have studied
photoluminescence and catalysis studies of multi-functional
rare-earth hybrid layered network, [Ho(H2cmp)(H2O)] (H5cmp
=
N-(carboxymethyl)iminodi(methylphosphonic acid).[27]
Also, there are other several Ho(III) polymers built by suc-
[30]
cinic acid,[28,29] 4-aminobenzoate,
and 5-nitroisophthalic
acid.[31] The successful preparation of polymer 2 gives us more
chance to study the properties of this kind of coordination
polymer.
FIG. 5. The coordination environment around the central Ho atom.
FIG. 6. 1-D chain structure of 2 (the C6H5 C(O) NH-C(S) NH C6H5- unit of L omitted for clarity).
FIG. 7. Crystal packing of 2 in the solid state along a-bxis.

LANTHANIDE COORDINATION POLYMERS
745
cm−1and 1410 cm−1), which are close to the reported val-
ues in the literatures.[32] The difference between νas(COO−)
and νs(COO−) is lower than 200 cm−1, which indicates the
µ2-bridging mode of the carboxylate group to the metal ion.
Stretching vibration peak of ν (N H) in the free ligand appears
at 3376 cm−1, which can be found in the two complexes (1:3381
cm−1; 2:3362 cm−1). The peak of δ (CO CH3) can be found in
1405 cm−1 for 1 or 1410 cm−1 for 2, respectively.
Fluorescence Spectrum
Recently, several coordination polymers containing Eu(III),
Tb(III) or other lanthanide have been explored due to their attrac-
tive emissive properties.[33,34] Usually metal–organic coordina-
tion polymers with lanthanide ion exhibit interesting photolu-
minescent properties. The fluorescence properties of complexes
1 and 2 and the corresponding ligand NaL were examined in the
solid state at room temperature.
As shown in Figure 8, the emission of NaL and complexes 1
and 2 were observed in a range of 300–460 nm by selective exci-
tation at 330 nm. The free NaL ligand shows two main emission
peaks with at 399 nm and 427 nm, respectively, which is due
to π–π* transitions. Complex 1 also shows two emission bands
at 392 nm and 422 nm, respectively, which are similar to NaL.
The fluorescence intensity of complex 1 is visible weakened.
The complex 2 shows one broad emission band around 439 nm.
Compared with the emission spectrum of NaL, red shift of 17
nm in 2 has been observed. Obviously, the fluorescence emission
of the complexes 1 and 2 might be attributed to ligand-to-ligand
charge transfer (L*→L).[35,36]
Thermogravimetric Analysis
The TG-DSC measurements of polymers 1 and 2 were de-
termined in the range of 20–800◦ in air.
As shown in Figure 9, polymer 1 underwent a three-step
decomposition process, with its first weight loss occurring at
64–175◦C. The weight loss corresponded to one coordinated
methanol molecule and two coordinated water molecules per
formula unit (found 8.5%, calcd 8.4%). Increasing temperature
FIG. 8. Fluorescence emission spectrum of the complexes 1 (a), 2 (b) and the
corresponding ligand NaL (c) in the solid state.
IR Spectroscopy
The infrared spectral data (400–4000 cm−1) of the two com-
plexes are in perfect agreement with their single-crystal X-
ray analyses. The strong absorption bands at 1660 cm−1 and
1400 cm−1are assigned to νas(COO−) and νs(COO−) vibra-
tions, respectively (1: 1603 cm−1 and 1405 cm−1; 2: 1604
FIG. 9. Thermogravimetric curve of complex 1.

746
Z. LI ET AL.
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led to the second decomposition of the compound in the range
of 187 to 516◦C. The final decomposition of the compound oc-
curred in the range of 516 to 600◦C. The latter two steps of
weight loss corresponded to the decomposition of the organic
ligand and the nitrate (found 65.8%, calculated 65.9%). Finally,
a plateau region is observed from 600 to 800◦C, giving a green
powder of mixture Pr2O3 and PrO2 (found 25.68%). For poly-
mer 1, there are one weak endothermic peak (128◦C), two weak
exothermic peaks (205◦C and 483◦C), and one strong exother-
mic peak (598◦C) in the DSC curve.
It can be seen from Figure 10, the polymer 2 indicated the fast
weight loss process in the temperature of 50–275◦C, and then
slowly lost weight from 275 to 600◦C (found 63.8%). The total
weight loss is corresponding to losses of solvent molecules, the
organic ligand HL and the nitrate anion. Finally, a plateau region
is observed from 600 to 800◦C. A white amorphous residue is
assigning to be Ho2O3(found 36.20%, calculated 35.7%). There
are one weak endothermic peak (161◦C) and one very strong
exothermic peak at 258◦C on the DSC curve of polymer 2.
12. Zhao, X.-Q., Zhao, B., Wei, S., and Cheng, P. Synthesis, structures, and lu-
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13. Michaelides, A., and Skoulika, S. Crystallographic evidence for ionic
molecular building blocks in the assembly of
a two-dimensional
metal−organic framework. Cryst. Growth Des., 2009, 9, 4998–5002.
14. Song, X.Q., Zhou, X.Y., Liu, W.S., Dou, W., Ma, J. X., Tang, X.L., and
Zheng, J.R. Synthesis, structures, and luminescence properties of lanthanide
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CONCLUSIONS
Two novel lanthanide coordination polymers with N-
benzoyl-Nꢀ-(4-benzoxy)thiourea have been prepared in solu-
tion. Their molecular structures were characterized by ele-
mental analyses, IR data and single crystal X-ray analysis.
They show novel double-cross one-dimensional chain struc-
tures. Their thermal data are consistent with the crystal data.
17. de Lill, D.T., de Bettencourt-Dias, A., and Cahill, C.L. Exploring lanthanide
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SUPPLEMENTARY MATERIALS
Crystallographic data for these structures reported in this pa-
per in the form of CIF files have been deposited with the Cam-
bridge Crystallographic Data Centre as supplementary publi-
cation Nos. 761427 and 761428 for the complexes 1 and 2
respectively. Copy of the data can be obtained free of charge on
application to CCDC, 12 Union Road, Cambridge CB2 IEZ, UK
(Fax: +44 1223 336 033; E-mail: deposit@ccdc.cam.ac.uk).

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