Increasing structure dimensionality of copper(I) complexes by varying the flexible thioether ligand geometry and counteranions

Article abstract of DOI:10.1021/ic060074x

This work focuses on the systematic investigation of the influences of pyrimidine-based thioether ligand geometries and counteranions on the overall molecular architectures. A N-containing heterocyclic dithioether ligand 2,6-bis-(2-pyrimidinesulfanylmethyl)pyridine (L1) and three structurally related isomeric bis(2-pyrimidinesulfanylmethyl)-benzene (L2-L4) ligands have been prepared. On the basis of the self-assembly of CuX (X = I, Br, Cl, SCN, or CN) and the four structurally related flexible dithioether ligands, we have synthesized and characterized 10 new metal-organic entities, Cu ₄(L1)₂I₄ 1, Cu₄(L1) ₂Br₄ 2, [Cu₂(L2)₂I ₂·CH₃CN]_n 3, [Cu(L3)I]_n 4, [Cu(L3)Br]_n 5, [Cu(L3)CN]_n 6, [Cu(L4)CN]_n 7, [Cu₂(L4)I₂]_n 8, [Cu₂(L4)(SCN) ₂]_n 9, and {[Cu₆I₅(L4) ₃](BF₄)·H₂O}_n 10, by elemental analyses, IR spectroscopy, and X-ray crystallography. Single-crystal X-ray analyses show that the 10 Cu(I) complexes possess an increasing dimensionality from 0D (1 and 2) to 1D (3-5) to 2D (6-9) to 3D (10), which indicates that the ligand geometry takes an essential role in the framework formation of the Cu(I) complexes. The influence of counteranions and π-π weak interactions on the formation and dimensionality of these coordination polymers has also been explored. In addition, the photoluminescence properties of Cu(I) coordination polymers 4-10 in the solid state have been studied.

Full text of DOI:10.1021/ic060074x

Inorg. Chem. 2006, 45, 4035−4046
Increasing Structure Dimensionality of Copper(I) Complexes by Varying
the Flexible Thioether Ligand Geometry and Counteranions
Rong Peng,† Dan Li,*,† Tao Wu,† Xiao-Ping Zhou,† and Seik Weng Ng‡
Department of Chemistry, Shantou UniVersity, Shantou, Guangdong 515063, P. R. China, and
Department of Chemistry, UniVersity of Malaya, 50603 Kuala Lumpur, Malaysia
Received January 15, 2006
This work focuses on the systematic investigation of the influences of pyrimidine-based thioether ligand geometries
and counteranions on the overall molecular architectures. A N-containing heterocyclic dithioether ligand 2,6-bis-
(2-pyrimidinesulfanylmethyl)pyridine (L1) and three structurally related isomeric bis(2-pyrimidinesulfanylmethyl)-
benzene (L2
CN) and the four structurally related flexible dithioether ligands, we have synthesized and characterized 10 new
metal organic entities, Cu4(L1)2I4 1, Cu4(L1)2Br4 2, [Cu2(L2)2I2 CH3CN]n 3, [Cu(L3)I]n 4, [Cu(L3)Br]n 5, [Cu(L3)CN]n
6, [Cu(L4)CN]n 7, [Cu2(L4)I2]n 8, [Cu2(L4)(SCN)2]n 9, and [Cu6I5(L4)3](BF4) H2O 10, by elemental analyses, IR
spectroscopy, and X-ray crystallography. Single-crystal X-ray analyses show that the 10 Cu(I) complexes possess
an increasing dimensionality from 0D (1 and 2) to 1D (3 5) to 2D (6 9) to 3D (10), which indicates that the ligand
−L4) ligands have been prepared. On the basis of the self-assembly of CuX (X ) I, Br, Cl, SCN, or
−
‚
{
‚
}
n
−
−
geometry takes an essential role in the framework formation of the Cu(I) complexes. The influence of counteranions
and π−π weak interactions on the formation and dimensionality of these coordination polymers has also been
explored. In addition, the photoluminescence properties of Cu(I) coordination polymers 4−10 in the solid state have
been studied.
Introduction
employed in the design of structural motifs is to combine
the metal ions and organic ligands that have been encoded
with the information necessary to predetermine the overall
structure of the resulting product. The design of organic
ligands is crucial in the construction of specific metallo-
supramolecular architectures, because of the organic units
that serve to connect the metallic centers and propagate the
structural information expressed in metal coordination pref-
erences throughout the extended structure. Therefore, once
Metallosupramolecular chemistry described by the spon-
taneous self-assembly of precursor metal ions and organic
ligands has been a rapidly developing research area in the
past decade.1,2 Interest in the area is justified by a rich
diversity of structural motifs, ranging from simple zero-
dimensional oligomers to three-dimensional matrixes,3 and
numerous potential applications, such as catalysis, sorption,
photochemistry, and magnetism.4 One sophisticated tactic
* To whom correspondence should be addressed. E-mail: dli@stu.edu.cn.
† Shantou University.
(3) See for examples: (a) Ruben, M.; Rojo, J.; Romero-Salguero, F. J.;
Uppadine, L. H.; Lehn, J.-M. Angew. Chem., Int. Ed. 2004, 43, 3644.
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‡ University of Malaya.
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2000, 100, 3483. (c) Moulton, B.; Zaworotko, M. J. Chem. ReV. 2001,
101, 1629. (d) Nishikiori, S.-I.; Yoshikawa, H.; Sano, Y.; Iwamoto,
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10.1021/ic060074x CCC: $33.50
Published on Web 04/22/2006
© 2006 American Chemical Society
Inorganic Chemistry, Vol. 45, No. 10, 2006 4035

Peng et al.
Chart 1
suitable metal ions are recognized, variation in the geometry,
size, and relative orientation of the donor groups of the
organic linker can afford a tremendous breadth of structural
motifs.
tion polymer, {[Cu6I5(L4)3](BF4)‚H2O}n 10, containing a 2D
inorganic [(Cu6I5)+]n layer composed of three different-
directioned intersecting 1D [CuI]n helices and connected by
ligand L4 through nitrogen and sulfur atoms (L4 ) 1,4-
bis(2-pyrimidinesulfanylmethyl)benzene, Chart 1).8 To fur-
ther probe the influence of systematic variations of ligand
structure and counteranions on the overall molecular archi-
tectures, we prepared a series of N-containing heterocyclic
thioether ligands, 2,6-bis(2-pyrimidinesulfanylmethyl)pyri-
dine (L1) and three structurally related isomeric thioether
ligands, bis(2-pyrimidinesulfanylmethyl)benzene (L2-L4)
(Chart 1). In this contribution, 10 Cu(I) complexes of these
ligands, Cu4(L1)2I4 1, Cu4(L1)2Br4 2, [Cu2(L2)2I2‚CH3CN]n
3, [Cu(L3)I]n 4, [Cu(L3)Br]n 5, [Cu(L3)CN]n 6, [Cu(L4)-
CN]n 7, [Cu2(L4)I2]n 8, [Cu2(L4)(SCN)2]n 9, and {[Cu6I5-
(L4)3](BF4)‚H2O}n 10, have been synthesized and charac-
terized. The series of coordination complexes (1-10) show
an increasing dimensionality from 0D to 3D and allow us to
have a possibility of systematically probing the effects of
modifying the ligand backbone and alternating counteranions
and attempting to control the precise topography (or micro-
architecture) of the arrays.
Taking into account the choice of organic ligands,
researchers have shown thioether ligands containing a flexible
backbone to be among the most important types of organic
ligands, because their flexibility and conformational freedom
allow for greater structural diversity. Heterocyclic-based
thioether ligands bearing S- and N-coordinating sites may
incline to coordinate metals with different modes, forming
a great variety of structurally interesting supramolecular
entities. For group 11 metals, a number of unusual and
interesting supramolecular Ag(I) arrays have already been
generated,5 but Cu(I) complexes with flexible heterocyclic
thioethers are less common.6
With regard to the metal center, the Cu(I) ion is a
particularly well-suited cation not only because of its labile
coordination modes with coordination numbers 2-5 but also
because the associated counteranion X (X ) I, Br, Cl, SCN,
or CN) can be incorporated as an essential element of the
framework; this offers the possibility for constructing various
nuclearities and great structural complexity.
As an extension of our study of the d10 metal complexes
with tailored properties and functions,7 we have embarked
on a program aimed at using flexible thioethers to prepare
Cu(I) coordination polymers. In the course of our work, we
have recently communicated a chiral 3D copper(I) coordina-
Experimental Section
General. The chemicals in this work were used as purchased
without further purification. Infrared spectra were obtained in KBr
disks on a Nicolet Avatar 360 FTIR spectrometer in the range
4000-400 cm-1. Photoluminescence analyses were performed on
a Perkin-Elmer LS 55 luminescence spectrometer. Elemental
analyses of C, H, and N were determined with a Perkin-Elmer
2400C elemental analyzer.
(5) (a) Han, L.; Wu, B.; Xu, Y.; Wu, M.; Gong, Y.; Lou, B.; Chen, B.;
Hong, M. Inorg. Chim. Acta 2005, 358, 2005. (b) Hong, M.; Zhao,
Y.; Su, W.; Cao, R.; Fujita, M.; Zhou, Z.; Chan, A. S. C. Angew.
Chem., Int. Ed. 2000, 39, 2468. (c) Hong, M.; Su, W.; Cao, R.; Fujita,
M.; Lu, J. Chem.sEur. J. 2000, 6, 427. (d) Li, K.; Xu, Z.; Fettinger,
J. C. Inorg. Chem. 2004, 43, 8018. (e) Caradoc-Davies, P. L.; Hanton,
L. R.; Lee, K. Chem. Commun. 2000, 783. (f) Chen, C.-L.; Su, C.-Y.;
Cai, Y.-P.; Zhang, H.-X.; Xu, A.-W.; Kang, B.-S. New J. Chem. 2003,
27, 790. (g) Caradoc-Davies, P. L.; Hanton, L. R. Chem. Commun.
2001, 1098. (h) Amoore, J. J. M.; Black, C. A.; Hanton, L. R.; Spicer,
M. D. Cryst. Growth. Des. 2005, 5, 1255. (i) Bu, X.-H.; Chen, W.;
Du, M.; Biradha, K.; Wang, W.-Z.; Zhang, R.-H. Inorg. Chem. 2002,
41, 437. (j) Bu, X.-H.; Xie, Y.-B.; Li, J.-R. Zhang, R.-H. Inorg. Chem.
2003, 42, 7422. (k) Hartshorn, C. M.; Steel, P. J. J. Chem. Soc., Dalton
Trans. 1998, 3935.
(6) (a) Amoore, J. J. M.; Hanton, L. R.; Spicer, M. D. Dalton Trans.
2003, 1056. (b) Song, R.-F.; Xie, Y.-B.; Li, J.-R.; Bu, X.-H.
CrystEngComm. 2005, 7, 249. (c) Caradoc-Davies, P. L.; Hanton, L.
R.; Hodgkiss, J. M.; Spicer, M. D. J. Chem. Soc., Dalton Trans. 2002,
1581. (d) Park, K.-M.; Yoon, I.; Seo, J.; Lee, J.-E.; Kim, J.; Choi, K.
S.; Jung, O.-S.; Lee, S. S. Cryst. Growth. Des. 2005, 5, 1707.
Preparation of Ligands. 2,6-Bis(2-pyrimidinesulfanylmethyl)-
pyridine, L1. 2,6-Bis(bromomethyl)pyridine (2.65 g, 10 mmol) was
added to a mixture of pyrimidine-2-thiolate (2.24 g, 20 mmol) and
(7) (a) Li, D.; Wu, T.; Zhou, X.-P.; Zhou, R.; Huang, X.-C. Angew. Chem.,
Int. Ed. 2005, 44, 4175. (b) Li, D.; Shi, W.-J.; Hou, L. Inorg. Chem.
2005, 44, 3907. (c) Li, D.; Wu, T. Inorg. Chem. 2005, 44, 1175. (d)
Wu, T.; Li, D.; Alg, S. W. CrystEngComm. 2005, 7, 514. (e) Hou, L.;
Li, D.; Shi, W.-J.; Yin, Y.-G.; Ng, S. W. Inorg. Chem. 2005, 44, 7825.
(f) Wu, T.; Zhou, R.; Li, D. Inorg. Chem. Commun. 2006, 9, 341.
(8) Peng, R.; Wu, T.; Li, D. CrystEngComm 2005, 7, 595.
(9) SMART, Version 5.060; Bruker Analytical X-ray Systems: Madison,
WI: 1997-1999.
(10) SAINT, Version V5.6; Bruker Analytical X-ray Systems: Madison,
WI.
4036 Inorganic Chemistry, Vol. 45, No. 10, 2006

Increasing Structure Dimensionality of Cu(I) Complexes
CH3ONa (1.19 g, 22 mmol) in ethanol (50 mL) under stirring. The
mixture was heated to 70 °C for 8 h with vigorous stirring. It was
then filtered and concentrated to give L1 as a pale-yellow solid,
which was washed with water and dried in air (65% yield). Mp:
95-97 °C. IR (KBr pellet, cm-1): 2921m, 2847w, 1638m, 1560s,
1450m, 1380s, 1168m, 1053s, 747w, 628w. Anal. Calcd for
C15H14N5S2: C, 55.02; H, 4.00; N, 21.39. Found: C, 55.10; H,
4.05; N, 21.28. Single crystals suitable for X-ray crystallography
were grown by slow diffusion of diethyl ether into an acetonitrile
solution of L1.
1,2-Bis(2-pyrimidinesulfanylmethyl)benzene, L2. 1,2-Bis(bromo-
methyl)benzene (2.64 g, 10 mmol) was added to a mixture of
pyrimidine-2-thiolate (2.24 g, 20 mmol) and CH3ONa (1.19 g, 22
mmol) in ethanol (50 mL) with stirring. The mixture was heated
to 60 °C for 6 h with vigorous stirring. It was then filtered and
concentrated to give L2 as a yellow oil, which afforded a light
yellow powder by recrystallization from CH2Cl2/Et2O/hexane. (70%
yield). Mp: 62-64 °C. IR (KBr pellet, cm-1): 3109w, 3052w,
2921m, 2848w, 1650m, 1552s, 1458w, 1380s, 1172s, 1078m, 800w,
767m. Anal. Calcd for C16H14N4S2: C, 58.87; H, 4.32; N, 17.16.
Found: C, 58.89; H, 4.26; N, 17.12.
1, 3-Bis(2-pyrimidinesulfanylmethyl)benzene, L3. Reaction of
1,3-bis(bromomethyl)benzene (2.64 g, 10 mmol) with pyrimidine-
2-thiolate (2.24 g, 20 mmol) and CH3ONa (1.19 g, 22 mmol) as
described above for L1 gave ligand L3 as a pale-yellow solid (80%
yield). Mp: 67-69 °C. IR (KBr pellet, cm-1): 3037w, 2922m,
2853w, 1638w, 1556s, 1376s, 1172m, 1061m, 795w, 709w. Anal.
Calcd for C16H14N4S2: C, 58.87; H, 4.32; N, 17.16. Found: C,
58.99; H, 4.12; N, 17.29. Single crystals suitable for X-ray
crystallography were grown by slow diffusion of diethyl ether into
a dichloromethane solution of L3.
1,4-Bis(2-pyrimidinesulfanylmethyl)benzene, L4. Reaction of
1,4-bis(bromomethyl)benzene (2.64 g, 10 mmol) with pyrimidine-
2-thiolate (2.24 g, 20 mmol) and CH3ONa (1.19 g, 22 mmol) as
described above for L1 gave L4 as a colorless needle crystal (90%
yield). Mp: 154-156 °C. IR (KBr pellet, cm-1): 2970m, 2925m,
2868w, 1728s, 1650w, 1548s, 1376s, 1180m, 1111m, 1066w, 775m,
747w. Anal. Calcd for C16H14N4S2: C, 58.87; H, 4.32; N, 17.16.
Found: C, 58.69; H, 4.39; N, 17.22. Single crystals suitable for
X-ray crystallography were grown by slow diffusion of diethyl ether
into a dichloromethane solution of L4.
Anal. Calcd for C34H31Cu2I2N9S4: C, 38.00; H, 2.91; N, 11.73.
Found: C, 37.78; H, 3.03; N, 11.77.
[Cu(L3)I]n, 4. A mixture of CuI (0.019 g, 0.1 mmol), L3 (0.032
g, 0.1 mmol), a KI-saturated solution (2.0 mL), and acetonitrile
(4.0 mL) was stirred for 15 min. It was then transferred and sealed
in a 13 mL Teflon-lined stainless steel reactor, which was heated
in an oven to 120 °C for 48 h and then cooled to room temperature
at a rate of 3 °C 0.5 h-1. The reaction mixture was filtered to give
a yellow solution. Yellow crystals of 4 were obtained by slow
evaporation in two weeks (38% yield). IR (KBr pellet, cm-1):
3048m, 2921m, 2848w, 1646w, 1552s, 1475w, 1377s, 1184s,
1074m, 804m, 755m. Anal. Calcd for C16H14CuIN4S2: C, 37.18;
H, 2.73; N, 10.84. Found: C, 37.21; H, 2.59; N, 10.70.
[Cu(L3)Br]n, 5. A mixture of CuBr (0.014 g, 0.1 mmol), L3
(0.032 g, 0.1 mmol), and acetonitrile (6.0 mL) was stirred for 15
min. It was then transferred and sealed in a 13 mL Teflon-lined
stainless steel reactor, which was heated in an oven to 120 °C for
48 h and then cooled to room temperature at a rate of 3 °C 0.5 h-1
.
Yellow block crystals of 5 were attained (27% yield). IR (KBr
pellet, cm-1): 3044w, 2921w, 2848w, 1617m, 1548s, 1426m,
1381s, 1185s, 1037m, 800w, 760w. Anal. Calcd for C16H14-
CuBrN4S2: C, 40.90; H, 3.00; N, 11.92. Found: C, 40.82; H, 2.85;
N, 12.01.
[Cu(L3)CN]n, 6. A mixture of CuCN (0.009 g, 0.1 mmol), L3
(0.032 g, 0.1 mmol), benzene (2.0 mL), and acetonitrile (4.0 mL)
was stirred for 15 min. It was then transferred and sealed in a 13
mL Teflon-lined stainless steel reactor, which was heated in an
oven to 120 °C for 48 h and then cooled to room temperature at a
rate of 3 °C 0.5 h-1. The reaction mixture was filtered to give a
pale-yellow solution. Pale-yellow plate crystals of 6 were attained
by slow evaporation in two weeks (20% yield). IR (KBr pellet,
cm-1): 2921w, 2847w, 2128m, 1642m, 1552s, 1380s, 1196w,
1168w, 1053m, 800w, 710w. Anal. Calcd for C17H14CuN5S2: C,
49.08; H, 3.39; N, 16.84. Found: C, 49.20; H, 3.25; N, 16.77.
[Cu(L4)CN]n, 7. A mixture of CuCN (0.009 g, 0.1 mmol), L4
(0.032 g, 0.1 mmol), benzene (2.0 mL), and acetonitrile (4.0 mL)
was stirred for 15 min. It was then transferred and sealed in a 13
mL Teflon-lined stainless steel reactor, which was heated in an
oven to 140 °C for 48 h and then cooled to room temperature at a
rate of 3 °C 0.5 h-1. Pale-yellow block crystals of 7 were attained
(54% yield). IR (KBr pellet, cm-1): 2917m, 2848w, 2132m, 1728w,
1642m, 1552s, 1377s, 1160w, 1054s, 763w. Anal. Calcd for C17H14-
CuN5S2: C, 49.04; H, 3.37; N, 16.84. Found: C, 49.14; H, 3.30;
N, 16.75.
Preparation of Cu(I) Complexes. Cu4(L1)2I4, 1. A solution of
CuI (0.038 g, 0.2 mmol) in acetonitrile (4 mL) was added to a
solution of L1 (0.032 g, 0.1 mmol) in DMF (2 mL). The reaction
mixture was stirred for 30 min to give a yellow solution. Slow
diffusion of diethyl ether into the filtrate yielded yellow block
crystals of 1 in two weeks (24% yield). IR (KBr pellet, cm-1):
2917w, 2880w, 1973w, 1589w, 1552s, 1450m, 1373s, 1184s, 812w,
759m, 637w. Anal. Calcd for C30H26Cu4I4N10S4: C, 25.43; H, 1.85;
N, 9.89. Found: C, 25.62; H, 1.74; N, 9.72.
Other methods: The procedure was the same as above using
CuI/CuBr/CuCl instead of CuCN in the presence of CH3CN and
other auxiliary solvents such as DMF, benzene, toluene, ethanol,
isopropyl alcohol, etc. Pale-yellow block crystals of 7 were obtained
directly or indirectly by growing them from mother liquors in a
month (15-38% yield).
Cu4(L1)2Br4, 2. The reaction of CuBr (0.029 g, 0.2 mmol) and
L1 (0.032 g, 0.1 mmol) as described above for 1 gave yellow block
crystals of 2 (18% yield). IR (KBr pellet, cm-1): 2921m, 2843w,
1744w, 1646m, 1556s, 1454m, 1373s, 1176s, 808w, 751m. Anal.
Calcd for C30H26Cu4Br4N10S4: C, 29.33; H, 2.13; N, 11.40.
Found: C, 29.15; H, 2.25; N, 11.24.
[Cu2(L2)2I2‚CH3CN]n, 3. A solution of CuI (0.019 g, 0.1 mmol)
in a KI-saturated solution (2 mL) was added to a solution of L2
(0.032 g, 0.1 mmol) in acetonitrile (4 mL). The reaction mixture
was stirred for 30 min to give a yellow solution that was then
filtered. Yellow block crystals of 3 were formed by slow evaporation
after three weeks (40% yield). IR (KBr pellet, cm-1): 2921w,
2848w, 1634m, 1565s, 1544s, 1381s, 1180s, 1074m, 800w, 764m.
[Cu2(L4)I2]n, 8. A mixture of CuI (0.038 g, 0.2 mmol), L4 (0.032
g, 0.1 mmol), hexane (2.0 mL), and acetonitrile (4.0 mL) was stirred
for 15 min. It was then transferred and sealed in a 13 mL Teflon-
lined stainless steel reactor, which was heated in an oven to 120
°C for 48 h and then cooled to room temperature at a rate of 3 °C
0.5 h-1. Pale-yellow plate crystals of 8 were obtained (23% yield).
IR (KBr pellet, cm-1): 2960m, 1730m, 1620w, 1550w, 1380s,
1180s, 1070s, 467m. Anal. Calcd for C8H7CuIN2S: C, 27.17; H,
1.99; N, 7.92. Found: C, 27.31; H, 1.89; N, 7.88.
[Cu2(L4)(SCN)2]n, 9. A mixture of CuSCN (0.024 g, 0.2 mmol),
L4 (0.032 g, 0.1 mmol), benzene (2.0 mL), and acetonitrile (4.0
mL) was stirred for 15 min. It was then transferred and sealed in
a 13 mL Teflon-lined stainless steel reactor, which was heated in
Inorganic Chemistry, Vol. 45, No. 10, 2006 4037

Peng et al.
Table 1. Summary of the Crystal Data and Structure Refinement Parameters for L1, L3, L4, and 1-10
L1
L3
L4
1
2
3
formula
fw
cryst syst
space group
a (Å)
C30H26N10S4
654.85
monoclinic
P21
6.3410(5)
12.2842(11)
20.2427(18)
90
90.296(2)
90
1576.8(2)
2
C16H14N4S2
326.43
monoclinic
Pc
13.953(3)
4.6420(10)
12.389(3)
90
103.550(4)
90
780.1(3)
2
C16H14N4S2
326.43
monoclinic
P21/a
12.0861(8)
4.6576(3)
27.9405(18)
90
102.513(1)
90
C30H26Cu4I4N10S4
1416.61
monoclinic
P21/n
13.2104(10)
9.9479(8)
15.2018(11)
90
95.757(1)
90
1987.7(3)
2
C30H26Cu4Br4N10S4
1228.65
monoclinic
P21/n
13.1282(9)
9.7714(7)
14.8445(10)
90
95.552(1)
90
1895.3(2)
2
C34H31Cu2I2N9S4
1074.80
triclinic
P1h
11.5768(6)
12.7908(6)
15.2079(7)
99.393(1)
101.457(1)
109.878(1)
2009.46(17)
2
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
Z
1535.47(17)
4
T (K)
293(2)
1.379
0.341
10096
293(2)
1.390
0.342
293(2)
1.412
0.348
12987
293(2)
2.367
5.466
12262
293(2)
2.153
6.691
11721
293(2)
1.776
2.840
17397
D
calcd (g cm-3
)
µ (mm-1
)
no. of reflns
collected
no. of unique
reflns
3790
5209
1925
3466
4601
4412
8989
Rint
0.0419
0.0238
0.0255
0.0270
0.0259
0.0159
R1 [I > 2σ(I)]
wR2 [I > 2σ(I)]
R1 [all reflns]
wR2 [all reflns]
0.0802
0.1663
0.1170
0.1860
0.0562
0.1417
0.0601
0.1497
0.0478
0.1168
0.0541
0.1270
0.0414
0.0935
0.0569
0.1002
0.0406
0.0889
0.0585
0.0956
0.0304
0.0793
0.0364
0.0872
F
fin (max/min)
0.848/-0.294
0.485/-0.182
0.444/-0.181
1.785/-0.921
1.514/-1.264
0.855/-0.814
(e Å-3
)
4
5
6
7
8
9
10
formula
fw
cryst syst
space group
a (Å)
C16H14CuIN4S2 C16H14CuBrN4S2 C17H14CuN5S2 C17H14CuN5S2 C8H7CuIN2S
C18H14Cu2N6S4 C48H44BCu6F4I5N12OS6
516.87
monoclinic
C2/c
469.88
monoclinic
C2/c
415.99
orthorhombic
Pnc2
415.99
orthorhombic
Pca21
353.66
monoclinic
P21/c
569.68
monoclinic
C2/c
2099.86
hexagonal
P63
29.755(2)
13.4624(9)
8.9729(6)
90
29.830(3)
13.1418(11)
8.7840(7)
90
14.0560(12)
4.8159(4)
12.5757(11)
90
12.3143(11)
4.8205(4)
28.265(3)
90
4.3816(5)
16.8590(19)
13.1538(14)
90
11.7761(14)
17.229(2)
10.4611(13)
90
13.5662(7)
13.5662
20.1867(11)
90
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
Z
99.333(2)
90
98.868(2)
90
90
90
90
90
93.384(2)
90
97.777(2)
90
90
120
3546.7(4)
8
3402.4(5)
8
851.28(13)
2
1677.9(3)
4
969.97(19)
4
2102.9(5)
4
3217.5(2)
2
T (K)
293(2)
1.936
3.213
293(2)
1.835
3.883
293(2)
1.623
1.538
293(2)
1.647
1.561
293(2)
2.422
5.599
293(2)
1.799
2.439
293(2)
2.167
4.599
D
calcd (g cm-3
)
µ (mm-1
)
no. of reflns
collected
no. of unique
reflns
15057
10473
4773
7961
5913
6334
17484
4135
3870
1809
2916
2223
2412
3830
Rint
0.0243
0.0339
0.0203
0.0281
0.0671
0.0351
0.0191
0.0592
0.1883
0.0629
0.0323
0.0509
0.1135
0.0624
0.0239
0.0322
0.0768
0.0389
0.0798
0.0227
0.0392
0.0892
0.0495
0.0986
0.0318
0.0335
0.0915
0.0375
R1 [I > 2σ(I)]
wR2 [I > 2σ(I)] 0.0816
R1 [all reflns]
0.0438
0.0962
wR2 [all reflns]
0.0699
0.1999
0.1198
0.1001
F
fin (max/min)
0.780/-0.549
0.560/-0.366
0.421/-0.469
0.605/-0.284
1.128/-0.861 0.606/-0.326
1.283/-0.805
(e Å-3
)
an oven to 140 °C for 48 h and then cooled to room temperature
at a rate of 3 °C 0.5 h-1. The reaction mixture was filtered to give
a yellow solution. Yellow transparent crystals of 9 were obtained
by slow evaporation in two weeks (11% yield). IR (KBr pellet,
cm-1): 2921m, 2848w, 2112m, 1638m, 1556m, 1385s, 1061s,
760w, 673w. Anal. Calcd for C18H14Cu2N6S4: C, 37.95; H, 2.48;
N, 14.75. Found: C, 37.80; H, 2.55; N, 14.68.
SAINT software,10 and absorption correction was applied.11 The
structures were solved by direct methods and refined by full-matrix
least-squares refinements based on F2. Anisotropic thermal param-
eters were applied to all non-hydrogen atoms. The hydrogen atoms
were generated geometrically (C-H ) 0.960 Å). The crystal-
lographic calculations were conducted using the SHELXL-97
programs. The orientation of the bridging cyanide group in 6 and
7 was found to be disordered, and the C and N atoms were refined
with a 50% probability of being C or N. In this paper, the atoms in
all such groups are labeled C/N(1), etc., as a reminder of the possible
disorder. Selected bond lengths and angles for complexes 1-10
are given in Tables 2-4.
{[Cu6I5(L4)3](BF4)‚H2O}n 10. See our previous communication8
for details.
Crystallography. Suitable crystals of L1, L3, L4, and 1-10
were mounted with glue at the end of a glass fiber. Data collection
was performed on a Bruker Smart Apex CCD diffractometer (Mo
KR, λ ) 0.71073 Å) using SMART.9 Parameters for data collection
and refinement of the three ligands and nine complexes are
summarized in Table 1. Reflection intensities were integrated using
(11) Sheldrick, G. M. SADABS; University of Go¨ttingen: Go¨ttingen,
Germany, 1996 and 2003.
4038 Inorganic Chemistry, Vol. 45, No. 10, 2006

Increasing Structure Dimensionality of Cu(I) Complexes
Table 2. Selected Bond Lengths (Å) and Bond Angles (deg) for
Complexes 1-3a
Table 4. Selected Bond Lengths (Å) and Bond Angles (deg) for
Complexes 7-10a
Complex 1
Complex 7
Cu(1)-I(2)
Cu(1)-N(3)
Cu(1)-S(2)
Cu(1)-S(1)
Cu(1)-Cu(2)
Cu(1)-I(1)
Cu(2)-I(1)
Cu(2)-Cu(2A)
Cu(2)-I(1A)
Cu(2)-N(1A)
Cu(2)-I(2)
2.5777(9)
2.077(4)
N(3)-Cu(1)-I(2)
N(3)-Cu(1)-I(1)
I(2)-Cu(1)-I(1)
S(2)-Cu(1)-S(1)
N(1A)-Cu(2)-I(2)
N(1A)-Cu(2)-I(1)
I(2)-Cu(2)-I(1)
N(1A)-Cu(2)-I(1A)
I(2)-Cu(2)-I(1A)
I(1)-Cu(2)-I(1A)
127.94(12)
119.97(12)
111.75(3)
160.01(5)
106.24(12)
113.33(12)
111.42(3)
105.87(12)
105.95(3)
113.45(3)
Cu(1)-C/N(2)
Cu(1)-C/N(1)
Cu(1)-N(4)
1.871(6)
1.889(4)
2.333(7)
2.521(2)
C/N(2)-Cu(1)-C/N(1)
C/N(2)-Cu(1)-N(4)
C/N(1)-Cu(1)-N(4)
C/N(2)-Cu(1)-N(2A)
C/N(1)-Cu(1)-N(2A)
N(2A)-Cu(1)-N(4)
154.96(16)
103.3(3)
93.9(3)
97.3
99.8
93.2
2.6200(17)
2.7380(17)
2.87771(6)
2.6510(9)
2.6220(8)
2.9649(15)
2.7770(9)
2.069(4)
Cu(1)-N(2A)
Complex 8
Cu(1)-I(1)
Cu(1)-I(1A)
Cu(1)-I(1B)
Cu(1)-N(1)
2.5602(7)
2.6939(7)
3.0338(8)
2.017(3)
N(1)-Cu(1)-I(1)
N(1)-Cu(1)-I(1A)
I(1)-Cu(1)-I(1A)
N(1)-Cu(1)-I(1B)
I(1)-Cu(1)-I(1B)
I(1A)-Cu(1)-I(1B)
138.75(9)
101.52(9)
112.99(2)
96.92(10)
92.51(2)
2.6174(9)
Complex 2
Cu(1)-Cu(2)
Cu(1)-Br(1)
Cu(1)-Br(2)
Cu(1)-N(3A)
Cu(1)-S(1A)
Cu(1)-S(2A)
Cu(2)-N(5)
Cu(2)-Cu(2A)
Cu(2)-Br(2)
Cu(2)-Br(2A)
Cu(2)-Br(1)
2.8162(8)
2.4448(7)
2.5341(7)
2.065(3)
2.5855(12)
2.7187(12)
2.040(3)
2.9820(12)
2.4682(7)
2.6897(8)
2.4756(7)
N(3A)-Cu(1)-Br(1)
N(3A)-Cu(1)-Br(2)
Br(1)-Cu(1)-Br(2)
S(1A)-Cu(1)-S(2A)
N(5)-Cu(2)-Br(2)
N(5)-Cu(2)-Br(1)
Br(2)-Cu(2)-Br(1)
N(5)-Cu(2)-Br(2A)
Br(2)-Cu(2)-Br(2A)
Br(1)-Cu(2)-Br(2A)
129.87(9)
120.24(9)
109.37(2)
161.10(4)
117.59(9)
107.64(9)
110.54(3)
105.56(9)
109.51(2)
105.21(3)
109.26(2)
Complex 9
Cu(1)-N(1)
Cu(1)-N(1A)
Cu(1)-S(2)
Cu(1)-S(2A)
Cu(2)-N(3)
Cu(2)-N(3A)
Cu(2)-S(2)
Cu(2)-S(2A)
S(2)-C(9)
2.031(2)
2.031(2)
2.4756(8)
2.4756(8)
1.900(2)
1.900(2)
2.5911(8)
2.5911(8)
1.648(3)
1.151(4)
N(1A)-Cu(1)-N(1)
N(1A)-Cu(1)-S(2A)
N(1)-Cu(1)-S(2A)
N(1A)-Cu(1)-S(2)
N(1)-Cu(1)-S(2)
S(2A)-Cu(1)-S(2)
N(3)-Cu(2)-N(3A)
N(3)-Cu(2)-S(2)
N(3A)-Cu(2)-S(2)
N(3)-Cu(2)-S(2A)
N(3A)-Cu(2)-S(2A)
S(2)-Cu(2)-S(2A)
N(3B)-C(9)-S(2)
144.47(12)
101.26(6)
98.80(6)
98.80(6)
101.26(6)
110.40(4)
147.71(15)
100.33(8)
99.53(8)
Complex 3
N(3B)-C(9)
99.53(8)
Cu(1)-I(1)
Cu(1)-I(2)
Cu(1)-N(4)
Cu(1)-N(7B)
Cu(2)-I(1)
Cu(2)-I(2)
Cu(2)-N(5)
Cu(2)-N(2A)
Cu(2)-Cu(1)
2.6166(4)
2.7125(5)
2.045(2)
2.072(2)
2.7040(4)
2.6587(4)
2.044(2)
2.066(2)
3.0262(6)
N(4)-Cu(1)-N(7B)
N(4)-Cu(1)-I(1)
N(7B)-Cu(1)-I(1)
N(4)-Cu(1)-I(2)
N(7B)-Cu(1)-I(2)
I(1)-Cu(1)-I(2)
N(5)-Cu(2)-N(2A)
N(5)-Cu(2)-I(2)
N(2A)-Cu(2)-I(2)
N(5)-Cu(2)-I(1)
N(2A)-Cu(2)-I(1)
I(2)-Cu(2)-I(1)
119.54(9)
112.37(7)
106.30(6)
106.05(7)
100.59(7)
111.380(15)
120.38(9)
110.55(7)
106.55(7)
104.42(7)
104.23(7)
110.345(14)
100.33(8)
103.36(4)
179.8(3)
Complex 10
Cu(1)-I(1)
2.6821(11)
2.6821(11)
2.6821(11)
2.6417(11)
2.6446(11)
2.6140(11)
2.6140(11)
2.6140(11)
2.049(6)
N(4E)-Cu(1)-S(2F)
N(4E)-Cu(1)-I(2)
S(2F)-Cu(1)-I(2)
N(4E)-Cu(1)-I(1)
S(2F)-Cu(1)-I(1)
I(2)-Cu(1)-I(1)
N(1C)-Cu(2)-S(1)
N(1C)-Cu(2)-I(3)
S(1)-Cu(2)-I(3)
N(1C)-Cu(2)-I(2)
S(1)-Cu(2)-I(2)
I(3)-Cu(2)-I(2)
116.53(18)
106.61(17)
106.65(6)
109.46(16)
104.07(6)
113.73(4)
112.68(19)
113.87(18)
106.01(6)
107.97(18)
106.27(6)
109.76(4)
Cu(1A)-I(1)
Cu(1B)-I(1)
Cu(1)-I(2)
Cu(2)-I(2)
Cu(2C)-I(3)
Cu(2D)-I(3)
Cu(2)-I(3)
a Symmetry codes for 1: A -x + 2, -y + 2, -z; for 2: A -x + 2, -y
+ 1, -z + 2; for 3: A x, y + 1, z; B x, y - 1, z.
Cu(1)-N(4E)
Cu(1)-S(2F)
Cu(2)-N(1C)
Cu(2)-S(1)
2.334(2)
2.030(7)
2.360(2)
Table 3. Selected Bond Lengths (Å) and Bond Angles (deg) for
Complexes 4-6a
a Symmetry codes for 7: A /2 - x, y, -1/2 + z; for 8: A x + 1, y, z;
B -x + 1, -y + 2, -z + 1; for 9: A -x + 2, y, -z + 5/2; B -x + 2, -y,
-z + 2; for 10: A -x + y, -x, z; B -y, x - y, z; C -x + y, -x + 1, z;
1
Complex 4
Cu(1)-I(1)
2.8424(6)
2.013(3)
2.013(3)
2.6865(6)
N(1)-Cu(1)-N(4B)
N(1)-Cu(1)-I(1A)
N(4B)-Cu(1)-I(1A)
N(1)-Cu(1)-I(1)
N(4B)-Cu(1)-I(1)
I(1A)-Cu(1)-I(1)
137.02(11)
107.65(8)
105.76(8)
93.34(8)
105.79(8)
101.351(19)
1
1
D -y + 1, x - y + 1, z; E -x, -y, z + /2; F y, -x + y, z + /2.
Cu(1)-N(1)
Cu(1)-N(4B)
Cu(1)-I(1A)
bis(2-pyrimidinesulfanylmethyl)pyridine (L1) were prepared
conveniently in high yields by the reactions of pyrimidine-
2-thiolate with 1,2-bis(bromomethyl)benzene, 1,3-bis(bromo-
methyl)benzene, 1,4-bis(bromomethyl)benzene, and 2,6-bis-
(bromomethyl)pyridine, respectively, in a 2:1 molar ratio
under heating conditions. L1-L3 are soluble in common
polar organic solvents, but L4 is less soluble except in DMF,
THF, and chlorinated solvents, which does not facilitate the
solution reaction between L4 and inorganic metal salts.
Complex 5
Cu(1)-N(4)
Cu(1)-N(1B)
Cu(1)-Br(1A)
Cu(1)-Br(1)
1.9891(18) N(4)-Cu(1)-N(1B)
140.37(7)
105.69(5)
106.83(5)
104.69(5)
93.08(5)
1.9972(17) N(4)-Cu(1)-Br(1A)
2.5418(4)
2.7008(4)
N(1B)-Cu(1)-Br(1A)
N(4)-Cu(1)-Br(1)
N(1B)-Cu(1)-Br(1)
Br(1A)-Cu(1)-Br(1)
97.216(14)
Complex 6
Cu(1)-C/N(1)
1.885(7)
C/N(1)-Cu(1)-C/N(1A) 155.2(4)
C/N(1)-Cu(1)-N(1A) 93.5(2)
C/N(1A)-Cu(1)-N(1A) 103.7(3)
C/N(1)-Cu(1)-N(1)
C/N(1A)-Cu(1)-N(1)
N(1A) -Cu(1)-N(1)
Cu(1)-C/N(1A) 1.885(7)
The complexes were synthesized with the corresponding
metal:ligand ratios. Crystals of 4-10 were obtained directly
from solvothermal conditions or grown indirectly from the
resulting mother liquor of solvothermal reactions, which
certainly contains richer content than the resulting solution
from the conventional method. This is the first time that the
hydro(solvo)thermal method was adopted in the construction
of metal-organic frameworks of flexible thioether ligands.
It is well-known that hydro(solvo)thermal reactions can not
only enhance metal-ligand interactions but also produce
Cu(1)-N(1A)
Cu(1)-N(1)
2.431(6)
2.431(6)
103.7(3)
93.5(2)
91.9(3)
a Symmetry codes for 4: A -x + 2, y, -z + /2; B x, y, z + 1; for 5:
A -x + 2, y, -z + /2; B x, y, z - 1; for 6: A -x + 1,-y, z.
5
1
Results and Discussion
Syntheses. The three isomeric bis(2-pyrimidinesulfanyl-
methyl)benzene compounds (L2-L4) and the related 2,6-
Inorganic Chemistry, Vol. 45, No. 10, 2006 4039

Peng et al.
metastable compounds that may not be accessible by the
conventional method, which promotes crystal growth because
the nature and temperature of the hydro(solvo)thermal fluid
can be varied over a wide range. The assembly of a number
of rigid ligands and metal salts produced various new
coordination polymeric solids with beautiful architectures and
interesting topologies.12 However, self-assembly reactions of
metal ions and flexible thioether ligands always adopted a
conventional solution method under ambient conditions
because the cleavage reaction on C-S of thioether ligands
took place easily under high temperature and pressure.5,6 In
this work, in view of the difficulty with copper(I) halides
and pseudo-halides being extreme insoluble in common
solvents in air, whereas they can be easily dissolved in hydro-
(solvo)thermal condition,7c-d,13 we tried the solvothermal
reactions of CuX (X ) I, Br, Cl, SCN, or CN) and thioether
ligands with a lower temperature and shorter reaction time,
avoiding the C-S bond cleavage. The stability of the four
thioether ligands in the order of L4 > L3 > L2 > L1 was
indicated through a large number of experiments in which
L4 could exist stably up to 140 °C, whereas the cleavage
on C-S of L1 had taken place below 100 °C to form black
metallic sulfide. Therefore, both the conventional solution
layer diffusion and the hydrothermal methods were adopted
in this work to deal with the difference in ligand stability.
Interestingly, complex 7 could be prepared under solvo-
thermal conditions with CuCN/CuI/CuBr/CuCl, and L4 in
mixed solvents of CH3CN and other auxiliary solvents. The
C-C bond cleavage and release of cyanide for organonitriles
are not surprising under solvothermal conditions.14 Except
for the direct addition of CuCN, the generation of cyanide 7
by the reactions of CuI/CuBr/CuCl might be due to the
decomposition of solvent acetonitrile at the relatively high
temperature (140 °C) and autogenous pressure of the reaction.
Presumably, the formation of the 2D polymer [Cu(L4)CN]n
might be because the stability of the crystal structures
composed of cyanide anion is superior to that of structures
composed of halogenous anion. Obviously, the stripping of
cyanide ion from a CH3CN solvent provides the source for
the capping anion in the aggregation of coordination
architectures.
Figure 1. Basic molecules of (a) L1, (b) L3, and (c) L4.
Table 5. Comparison of Torsion Angles and Dihedral Angles of Free
Ligands
TAa (deg)
DAb (deg)
DAc (deg)
L1
L3
L4
-79.5(5), -84.0(5), 79.4(5), 84.5(5)
92.5(5), 98.1(5)
-84.0(2), 85.2(2)
61.5-70.3
61.1-63.1
66.5-68.2
16.7-19.9
67.4
0
a Torsion angles of C(pyrimidyl)-S-C(methylene)-C(phenyl). b Dihedral angles
between the central phenyl and outer pyrimidine rings. c Dihedral angles
between two outer pyrimidine rings.
the torsion angles and dihedral angles between L1 and L3,
although only the N atom in the pyridyl ring of L1 is replaced
by a carbon atom in the central phenyl of L3. It seems that
the interaction of the Npyridine lone-pair electrons plays an
important role in determining the conformation of the free
ligand L1, placing the two pyrimidyl with the central pyridyl
in a syn conformation. The L1 molecule containing one
Npyridine and two S as a tridentate ligand possesses the
expected ability to chelate a metal atom, forming two five-
membered rings (NC2SM). In contrast, the half-spiral
structure of the L4 molecule with the two pyrimidyl groups
in the anti positions of the central benzene seems to be
favorable for the formation of a helical complex. Different
from L1 and L3, the outer pyrimidine groups in L4 are
coplanar and orient trans to each other, which conform L4
to a Z-like structure.
Adjacent molecules of ligand L1 are organized into a 1D
zigzag chain by weak π-π stacking interactions of 3.53-
3.64 Å between the parallel neighboring aromatic rings. (see
Figure S1a in the Supporting Information) This stacking is
apparently different from those in L3 and L4 (Figure S1b
and S1c in the Supporting Information). Adjacent molecules
of L3 or L4 molecules stack on each other along the b
direction by weak π-π interaction (L3, 3.56-3.73 Å; L4,
3.53-3.64 Å). They form similar one-dimensional ribbons
along the crystallographic b direction.15 In addition, there
Crystal Structures. Free ligands. Three ligands, L1, L3,
and L4, all crystallize in a monoclinic system with two
independent molecules, one independent molecule, and two
crystallographically nonequivalent half-molecules in asym-
metric units, respectively. As shown in Figure 1, all three
ligands are twisted; their torsion angles and dihedral angles
for structural comparison are summarized in Table 5. It
should be noted that there is a considerable difference in
(12) (a) Rabenau, A. Angew. Chem., Int. Ed. 1985, 24, 1026. (b) Wang,
R.; Zhou, Y.; Sun, Y.; Yuan, D.; Han, L.; Lou, B.; Wu, B.; Hong, M.
Cryst. Growth. Des. 2005, 5, 251. (c) Feng, S.; Xu, R. Acc. Chem.
Res. 2001, 34, 239. (d) Lu, J. Y. Coord. Chem. ReV. 2003, 246, 327.
(13) (a) Chesnut, D. J.; Zubieta, J. Chem. Commun. 1998, 1707. (b) Chesnut,
D. J.; Kusnetzow, A.; Birge, R. R.; Zubieta, J. Inorg. Chem. 1999,
38, 2663. (c) Teichert, O.; Sheldrick, W. S. Z. Anorg. Allg. Chem.
2000, 626, 2196.
(15) (a) Janiak, C. Dalton Trans. 2000, 3885. (b) Munakata, M.; Kuroda-
Sowa, T.; Maekawa, M.; Honda, A.; Kitagawa, S. J. Chem. Soc.,
Dalton Trans. 1994, 2771. (c) Munakata, M.; Wu, L. P.; Yamamoto,
M.; Kuroda-Sowa, T.; Maekawa, M. J. Am. Chem. Soc. 1996, 118,
3117. (d) Sugimori, T.; Masuda, H.; Ohata, N.; Koiwai, K.; Odani,
A.; Yamauchi, O. Inorg. Chem. 1997, 36, 576.
(14) (a) Huang, X.-C.; Zheng, S.-L.; Zhang, J.-P.; Chen, X.-M. Eur. J.
Inorg. Chem. 2004, 1024. (b) Zhang, J.-P.; Lin, Y.-Y.; Huang, X.-C.;
Chen, X.-M. J. Am. Chem. Soc. 2005, 127, 5495.
4040 Inorganic Chemistry, Vol. 45, No. 10, 2006

Increasing Structure Dimensionality of Cu(I) Complexes
Figure 3. Complex 3. (a) View of the coordination environment of the
copper atoms, and (b) schematic representation of the formation of a 1D
chain. Symmetry code: A x, y + 1, z; B x, y - 1, z.
metry. The chairlike structure is defined by three CuICuI
diamonds with each one sharing one edge with the next.
Although only the central diamond is flat, the four Cu(I)
atoms and four iodine atoms are precisely coplanar, thus
forming two parallelograms. The Cu‚‚‚Cu separation dis-
tances in the copper parallelogram show remarkable variation
with short sides of 2.87771(6) Å, long sides of 3.94998(9)
Å, and a short diagonal of 2.9649(15) Å, which show the
[Cu4I4] contained in 1 being more of a “flattened chair” than
those reported similar substructures.6b,17
Each L1 ligand bridges between the two Cu(I) atoms on
one side of one Cu4I4 structure, exhibiting a special coor-
dination mode with the central SNS atoms chelating to Cu(1)
and N atom coordinating to Cu(2A). The coordination of
the terminal pyrimidine ring to the metal centers forces L1
into a slightly shrinking conformation, increasing the dihedral
angles between the central phenyl and outer pyrimidine rings
from 61.5-70.3° of free ligand to 85.8-92.4°. The adjacent
pyrimidine rings from different tetramers are aligned in an
offset fashion; they are approximately parallel to each other
with the separation of 3.2053-3.2441 Å (Figure 2b) and
indicate the presence of face-to-face π-π stacking interac-
tions.15
Figure 2. (a) Perspective view of 1; (b) view of crystal packing of 1.
Symmetry code: A -x + 2, -y + 2, -z.
are weak C-H‚‚‚S interactions (L3: S‚‚‚H, 3.334 Å; S‚‚‚H-
C, 151.8°; L4: S‚‚‚H, 3.311 Å; S‚‚‚H-C, 160.8°) between
adjacent π-π stacking columns in L3 and L416 that are not
found in L1, and these weak interactions link the ribbons
into a 2D undulating sheet. Generally, these weak interactions
contribute to the formation and stability of the architectures.
By analogy, we assume that the differences exhibited in the
crystal structures by the three ligands may give rise to
different metal-ligand interactions and so different products
upon complexation.
Discrete Tetranuclear Complexes of [Cu4(L1)2I4] (1)
and [Cu4(L1)2Br4] (2). The crystal structure of 1 consists
of two L1 ligands and a Cu4I4 stepped cubane, which
contains two types of Cu(I) cations and two types of I anions
(µ2-I and µ3-I) (Figure 2). One type of Cu (Cu(1)) is
coordinated primarily by two I ions and one Npyridine atom,
which define a slightly distorted trigonal planar arrangement,
with the three angles ranging from 111.75(3) to 127.94(12)°
and a sum of 359.7°. The 2.6200(17)-2.7380(17) Å dis-
tances between two pendant thioether sulfur atoms and the
Cu(1) atom are significantly longer than those found in other
four-coordinate copper(I) systems (typically ≈2.35 Å),6
indicating only Cu‚‚‚S weak interactions. Another type of
Cu (Cu(2)), in the tetrahedral site, is coordinated to three I
atoms and one Npyrimidine from another L1 molecule. The bond
angles around Cu(2), in the range 105.87(12)-113.45(3)°,
are normal for a tetrahedron coordination geometry. The
Cu-N distances are 2.069(4)-2.077(4) Å; the Cu-I dis-
tances are 2.5777(9)-2.7770(9) Å and are comparable to
those found in reported copper iodines.6,17
A similar reaction of CuBr with L1 gave complex 2
[Cu4(L1)2Br4] (Figure S2 in the Supporting Information).
Complexes 1 and 2 are isostructural and crystallize in the
same monoclinic space group, P21/n.
1D Complexes of [Cu2(L2)2I2‚CH3CN]n (3), [Cu(L3)I]n
(4), and [Cu(L3)Br]n (5). Complex 3 shows an infinite 1D
chain structure and contains two crystallographically inde-
pendent Cu(I) centers. As shown in Figure 3a, two Cu(I)
(16) Cargill Thompson, A. M. W.; Bardwell, D. A.; Jeffery, J. C.; Rees,
L. H.; Ward, M. D. J. Chem. Soc., Dalton Trans. 1997, 721.
(17) (a) Rath, N. P.; Holt, E. M.; Tanimura, K J. Chem. Soc., Dalton Trans.
1986, 2303. (b) Kuhn, N.; Fawzi, R.; Grathwohl, M.; Kotowski, H.;
Steimann, M. Z. Anorg. Allg. Chem. 1998, 624, 1937.
The tetrameric Cu4I4 core in 1 is a distorted chairlike
structure with crystallographically imposed inversion sym-
Inorganic Chemistry, Vol. 45, No. 10, 2006 4041

Peng et al.
ions display similar distorted tetrahedral coordination ge-
ometry comprised of two bridging iodine ions and two N
donors from different pyrimidine rings of two distinct
ligands, with the angles varying from 100.59(7) to 120.38(9)°.
The Cu-I and Cu-N bond lengths are in the range of
2.6166(4)-2.7125(5) and 2.044(2)-2.072(2) Å, respectively,
which are normal ranges.6,17 Two µ2-iodine ions are bound
to two adjacent, different Cu(I) centers, forming a CuI2Cu
rhomboid dimer in which the Cu(I) centers are separated by
a distance of 3.0262(6) Å. Two bis-monodentate L2 ligands
wrap around the Cu-Cu axis of two adjacent CuI2Cu
rhomboid dimers, with a separation of 9.7664(2) Å, giving
rise to a [Cu2L22]2+ double-helical subunit. The subunits
further extend along the crystallographic b axis by µ2-I atoms
bridging the [Cu2(L2)2]2+ double-helical dinuclear subunits
to form an infinite 1D chain (Figure 3b). In other words,
[Cu2(L2)2I2]n can be considered as being a double-stranded
helix generated by the intertwining of two single-stranded
helical chains and separated by µ2-iodine ions. All Cu atoms
are almost in line with a Cu1-Cu2-Cu1A angle of 177.6°
and are positioned at the central helical axis. Many discrete
helical structures18 and infinite helical coordination poly-
mers19 have been synthesized over the past decade. However,
to the best of our knowledge, such a 1D chain formed by
discrete double helicates linked via bridging iodine ions has
not been reported to date. Except for C-H‚‚‚S weak
interactions (S‚‚‚H, 3.171Å; S‚‚‚H-C, 169.0°) found be-
tween adjacent chains,16 there are no obvious intermolecular
π-π interactions between aryl rings. In addition, acetonitrile
solvent molecules are filled in the interspace of adjacent
chains and show no interactions with other molecules.
The reaction of CuI with L3 leads to the formation of a
one-dimensional double-stranded helical complex [Cu(L3)I]n
4, which contains a CuI2Cu connector different from that in
3. As shown in Figure 4a, the Cu(I) adopts a distorted
tetrahedron arrangement with a coordination sphere provided
by two µ2-iodine ions and two Npyrimdine donors from different
L3 ligands. The bond angles around Cu(1), in the range
93.34(8)-137.02(11)°, form a more distorted geometry than
that in 3, and the Cu-I bond distances ranging from
2.6865(6) to 2.8424(6) Å are significantly longer than those
in 3 and other tetrahedral Cu(I) coordination systems.6,17 Each
pair of adjacent Cu(I) atoms is bridged by an L3 ligand to
afford a single chiral helical chain running along the c
direction with a short pitch of 8.973 Å. Two adjacent single-
stranded helical chains with the same handedness are further
joined together through a middle CuI2Cu connector to form
a double-stranded helix (Figure 4b). Such double-stranded
helical chains formed by halogen-ion bridging have not been
Figure 4. Complex 4. (a) View of the coordination environment of the
copper atoms, and (b) schematic representation of the formation of the 1D
5
chain. Symmetry codes: A -x + 2, y, -z + /2; B x, y, z + 1.
documented. It is noteworthy that although the double-
stranded helical chain is a chiral one, with either left- or
right-handedness, the whole structure is achiral with centro-
symmetric space group C2/c, which originates from the
alternate stacking of helical chains with opposite chirality.
The L3 pyrimidine rings at each side of the helix are arranged
in a parallel fashion with an interring distance of 6.5766-
6.7192 Å, resulting in a structure suitable for forming
aromatic intercalation.19d So adjacent chiral helices are
racemically packed through intercalation of the lateral
pyrimidine rings in a zipperlike, offset fashion (face-to-face
distances of 3.2769-3.3866 Å) into two-dimensional layers
parallel to the bc plane (Figure 4b). Similar zipperlike
intercalations have been reported previously in some three-
dimensional coordination architectures constructed by two-
dimensional layers.20 These 2D layers are further extended
into the final three-dimensional (3D) networks through strong
aromatic π-π interactions between phenyl rings from
adjacent layers, with a center-to-center distance of about
3.809 Å.
To examine the role of halide atoms in the formation of
double-stranded helical chains, we used CuBr instead of CuI
to produce complex 5. Single-crystal X-ray diffraction
analysis has proved that complexes 4 and 5 are isomorphous
(see Figures S3 in the Supporting Information).
2D complexes of [Cu(L3)CN]n (6), [Cu(L4)CN]n (7),
[Cu2(L4)I2]n (8), and [Cu2(L4)(SCN)2]n (9). As shown in
Figures 5 and 6, complexes 6 and 7 show a similar 2D
undulating sheet formed by ligand molecules bridging
[Cu(CN)]n chains. For the crystals of 6, with block morphol-
ogy, the asymmetric unit consists of a copper site with a
site occupancy of 0.5, one C/N site of cyanide and half L3
molecules. This is different from the basic unit of 7, which
contains a Cu(I) ion, a complete ligand (L4), and one µ-CN-
anion. The Cu(1) center in 6 is coordinated to two C/N atoms
from cyanide groups in a nonlinear fashion, and C/N(1)-
(18) (a) Guo, D.; He, C.; Duan, C. Y.; Qian, C. Q.; Meng, Q. J. New J.
Chem. 2002, 26, 796. (b) Lehn, J.-M.; Rigault, A. Angew Chem., Int.
Ed. 1988, 27, 1095. (c) Hannon, M. J.; Painting, C. L.; Alcock, N.
W. Chem. Commun. 1999, 2023.
(19) (a) Huang, X.-C.; Zhang, J.-P.; Lin, Y.-Y.; Chen, X.-M. Chem.
Commun. 2005, 2232. (b) Mamula, O.; Zelewsky, A. V.; Bark, T.;
Bernardinelli, G. Angew. Chem., Int. Ed. 1999, 38, 2945. (c) Tabellion,
F. M.; Seidel, S. R.; Arif, A. M.; Stang, P. J. Angew. Chem., Int. Ed.
2001, 40, 1529. (d) Chen, X.-M.; Liu, G.-F. Chem.sEur. J. 2002, 8,
4811. (e) Cui, Y.; Lee, S. J.; Lin, W. J. Am. Chem. Soc. 2003, 125,
6014.
(20) (a) Tong, M.-L.; Chen, H.-J.; Chen, X.-M. Inorg. Chem. 2000, 39,
2235. (b) Zheng, S.-L.; Tong, M.-L.; Fu, R.-W.; Chen, X.-M.; Ng,
S.-W. Inorg. Chem. 2001, 40, 3562.
4042 Inorganic Chemistry, Vol. 45, No. 10, 2006

Increasing Structure Dimensionality of Cu(I) Complexes
these interactions are taken into account, the Cu(1) atom has
a very distorted 2+1+1 tetrahedral environment, with the
bond angles around Cu(1) varying substantially from 91.9(3)
to 155.2(4)°. In 7, the Cu(I) center has coordination environ-
ment similar to that of 6 and is bound by two C/N atoms
from cyanide groups and two pyrimidine nitrogen atoms from
two distinct L4 ligands. The mean values of the Cu-C/N,
Cu-Npyrimdine, and C/N-C/N distances (1.880(5), 2.427(5),
and 1.152(6) Å, respectively) and the distorted tetrahedral
coordination geometry (bond angles in the 93.2-154.96(16)°
range) in 7 can compare with those of 6. The extended
infinite zigzag [Cu-CN]n chains running along the b axis,
with a Cu‚‚‚Cu separation between adjacent chains of
14.0560(4) and 14.14(1) Å in 6 and 7, respectively, are
further connected by parallel ligand molecules via Cu-
Npyrimdine coordination interactions, affording a two-dimen-
sional pucker layer. The 2D sheet in 7 expresses a stronger
corrugated figure than that in 6. The aromatic face-to-face
distance of 3.5619-3.886 Å between the neighboring ligand
reveals weak π-π interactions.15 Each sheet reverses from
its neighbors and lies on top of the others along the c or a
axis for complex 6 or 7, respectively. This is consistent with
different orthorhombic space groups Pnc2 and Pca21, which
show an ABAB packing mode (Figure 5b and 6b).
Figure 5. (a) View of the 2D network in 6 from the c axis, and (b) packing
diagram for 6. Symmetry codes: A -x + 1, -y, z; B -x + 1, -y + 1, z.
Unlike that in other Cu(I) halide complexes discussed
above, the difference in ligand spacers in L3 and L4 in 6
and 7, respectively, causes only subtle geometrical differ-
ences in their CuCN complexes and does not greatly
influence the whole structure topology. We suppose that the
stability of the [Cu-CN] zigzag chain formed by µ-CN-
coordinated to Cu(I) seems to be a determining factor
affecting the coordination frameworks of 6 and 7, which
overcome the influence of different ligands (L3 and L4) on
the metal-ligand frameworks.
The crystal structure of [Cu2(L4)I2]n (8) contains a very
simple asymmetric unit, but the resulting extended structure
is a robust lamellar solid (Figure 7). Each tetrahedral Cu(I)
ions is coordinated to three µ3-I ligands, which generates a
1D [CuI]n staircase along the crystallographic a axis, leaving
one site available for the fourth bond with ligand L4 through
the pyrimidine nitrogen atom (Cu(1)-N(1), 2.017(3) Å). The
geometry of Cu(1) is quite distorted, with I-Cu-I angles
ranging from 96.92(10) to 138.75(9)° and N-Cu-I bond
angles in the range of 92.51(2)-112.99(2)°. The Cu(1)-
I(1B) distance of 3.0338(8) Å is remarkably longer than the
other two similar coordination bonds (Cu(1)-I(1), 2.5601(7)
Å; Cu(1)-I(1A), 2.6939(7) Å), as well as those found in
reported copper iodides.6,17 Therefore, the long Cu-I bonds
can be considered as being spacers bridging two zigzag single
chains and forming a [CuI]n staircase structure. The distances
(3.327-3.883 Å) between diagonal copper atoms are too
Figure 6. (a) View from the a axis showing the 2D network of 7, and (b)
packing diagram for 7. Symmetry codes: A 1/2 - x, y, -1/2 + z; B x, y -
1, z.
C/N(1B) bond lengths of 1.134(14) Å and Cu-C/N distances
of 1.885(7) Å are comparable to those found in reported
copper cyanide.21 Besides these strong bonds, there are also
weak coordination interactions between the copper and two
adjacent thioether N atoms with the same distance of 2.431(6)
Å, which was above the range of 1.96-2.14 Å found for
the Cu(I)-N bond distances of such compounds7b,22 but
within sum of the van der Waals radius of 2.95 Å. If all
(21) (a) Zhang, X.-M.; Fang, R.-Q. Inorg. Chem. 2005, 44, 3955. (b)
Hanika-Heidl, H.; Etaiw, S. E. H.; Ibrahim, M. S.; El-din, A. S. B.;
Fischer, R. D. J. Organomet. Chem. 2003, 684, 329. (c) Stocker, F.
B.; Staeva, T. P.; Rienstra, C. M.; Britton, D. Inorg. Chem. 1999, 38,
984. (d) Chesnut, D. J.; Plewak, D.; Zubieta, J. J. Chem. Soc., Dalton
Trans. 2001, 2567.
(22) (a) Wang, R.-H.; Hong, M.-C.; Su, W.-P.; Liang, Y.-C.; Cao, R.; Zhao,
Y.-J.; Weng, J.-B. Bull. Chem. Soc. Jpn. 2002, 75, 725. (b) Simmons,
C. J.; Lundeen, M.; Seff, K. Inorg. Chem. 1979, 18, 3444.
Inorganic Chemistry, Vol. 45, No. 10, 2006 4043

Peng et al.
Figure 8. Complex 9. (a) Views of the copper(I) coordination environment,
and (b) perspective view of the 2D network. Symmetry codes: A -x + 2,
5
y, -z + /2; B -x + 2, -y, -z + 2.
adopt a distorted tetrahedral geometry and are occupied by
two N atoms from another two bridging thiocyanate ligands.
The geometry of all Cu(I) centers is quite distorted, with
N-Cu-N angles of 144.47(12)-147.71(15)°, S-Cu-S
angles of 103.36(4)-110.40(4)°, and N-Cu-S angles rang-
ing from 98.80(6) to 101.26(6)°. The thiocyanate groups
function as tridentate µ-S,S,N bridges connecting three
different metal centers, resulting in a [CuSCN]n displaced
stair polymer extended along the c axis of the unit cell. This
is a new framework for the CuSCN system, and similar
examples of this displaced stair motif have been found only
for [CuX]n (X ) Br, I).23 However, a number of comparable
stair polymer arrangements have been observed before for
[Cu2(SCN)2(bpe)]n (bpe ) trans-1,2-bis(4-pyridyl)ethane),
[Cu(SCN)(dpt)]n (dpt ) 2,4-bis(4-pyridyl)-1,3,5-triazine), and
[Cu(SCN)(2-Mepy)]n (2-Mepy ) 2-methylpyridine)24 (see
comparison between [Cu(SCN)]n displaced stair polymer and
stair polymer in Figure S4 in the Supporting Information).
The generation of a displaced stair instead of a stair polymer
indicates that the steric constraint on the ligands force the
stair to deviate.
Figure 7. (a) Asymmetric unit of 8; (b) perspective view of the 2D network
of 8; and (c) stacking pattern for 8. Symmetry codes: A x + 1, y, z; B -x
+ 1, -y + 2, -z + 1.
long to consider Cu‚‚‚Cu interactions. The bis-monodentate
ligand acts as a bridge between [CuI]n staircases and serve
to propagate the 1D polymeric chains into infinite 2D layers.
The interplanar spacing of 3.5142 Å indicates π-π interac-
tions between adjacent L4 molecules.15 Each sheet is reversed
and offset from its neighbors, expressing an ABAB stacking
pattern (Figure 7c). No remarkable short contacts or note-
worthy aryl-aryl interactions are found between adjacent
sheets.
X-ray structural analysis of 9 reveals a two-dimensional
sheet structure (Figure 8) containing two different Cu(I)
centers. Tetrahedral Cu(1) is coordinated by two µ2-S atoms
from two bridging thiocyanate ligands and by two N atoms
from different bis-monodentate L4 molecules. The other ends
of the two µ2-S atoms are bound to the second Cu(I) center,
Cu(2), forming a CuS2Cu cyclic unit that serves as the
polymeric link for the system. The Cu(I) centers are separated
by a relatively long distance of 3.019(1) Å, which is
comparable to that of 3.0262(6) Å in 3 and shorter than those
of 3.4560(1) Å in 4 and 3.327-3.883 Å in 8 but longer than
the sum of their van der Waals radii (2.8 Å), indicating no
Cu-Cu weak interaction. The remaining two sites of Cu(2)
(23) (a) Massaux, M.; Ducreux, G.; Chevalier, R.; Bihan, M.-T. L. Acta
Crystallogr., Sect. B 1978, 34, 1863. (b) Fisher, P. J.; Taylor, N. F.;
Harding, M. M. J. Chem. Soc. 1960, 2303.
(24) (a) Barnett, S. A.; Blake, A. J.; Champness, N. R.; Wilson, C. Chem.
Commun. 2002, 1640. (b) Blake, A. J.; Brooks, N. R.; Champness,
N. R.; Crew, M.; Hanton, L. R.; Hubberstey, P.; Parsons, S.; Schro¨der,
M. J. Chem. Soc., Dalton Trans. 1999, 2813. (c) Healy, P. C.;
Pakawatchai, C.; Papasergio, R. I.; Patrick, V. A.; White, A. H. Inorg.
Chem. 1984, 23, 3769.
4044 Inorganic Chemistry, Vol. 45, No. 10, 2006

Increasing Structure Dimensionality of Cu(I) Complexes
Figure 10. Emission spectra of the Cu(I) complexes in the solid state at
room temperature.
Table 6. Emission Data of the Cu(I) Complexes
complex
Cu-Cu (Å)
Cu-N (L) (Å)
2.013(3)
1.9972(17)
2.431(6)
λ
ex (nm)
λ
em (nm)
4
5
6
7
8
9
10
3.4560(1)
3.4343(1)
4.8159(1)
4.820(4)
3.327-3.883 2.017(3)
3.019(2) 2.031(2)
395, 442
390
393
525
535
560
562
517
525
535
2.333(7)-2.521(2) 393
393, 437
338, 393
3.674-3.754 2.030(7)-2.049(6) 345, 385
upon irradiation of ultraviolet light in the solid state.
Unfortunately, no photoluminescence measurement in solu-
tion can be carried out, because 4-10 cannot be dissolved
in common organic solvents. The emission spectra of the
seven Cu(I) complexes have been recorded in the solid state
at room temperature, and the spectral data are summarized
in Table 6. In comparison with the photoluminescence
properties of reported complexes of cuprous halides and
heterocyclic ligands, we tentatively assigned the emission
of the Cu(I) complexes as being a metal center (MC) d-s
state or a metal-to-ligand charge-transfer (MLCT) state for
their broad and structureless emission spectra, as free ligands
L1-L4 do not show photoluminescence.7b,14b,25 The emission
peaks for 6 and 7 are quite similar, with only 2 nm difference
in the yellow range (Figure 10), which is in agreement with
their similar extended architectures. Compared to 6 and 7,
complexes 4, 5, and 8-10 have higher-energy transitions,
which may be ascribed to the different coordination bonds
as shown Table 6. Because the energies of a frontier
molecular orbit would certainly be dependent on the extent
of mixing due to metal-ligand covalent interaction, the large
red shift of the emission maximum of 6 and 7 may be
ascribed to a weak coordination interaction of the long Cu-N
and Cu-Cu distances.
Figure 9. Complex 10. (a) Single [CuI]n helix; (b) [(Cu6I5)+]n layer
constructed by intersecting [CuI]n helices extended along the [100], [010],
and [110] directions. (c) 3D view showing the alternate inorganic-organic
stacking (green, purple, yellow, and pale-blue spheres represent Cu, I, B,
and F atoms, respectively).
In parallel running, infinite [CuSCN]n stairs are tied
together by bridging bis-bidentate L4 ligands to form 2D
sheets. Adjacent sheets pack closely along the a axis with a
staggered arrangement so that the [(CuSCN)2]n displaced stair
polymers sit perpendicularly above L4 ligands in adjacent
sheets. There are face-to-face stacking interactions between
the intersheet parallel pyrimidine rings, with a centroid-
centroid separation of 3.607 Å.15
3D complex of {[Cu6I5(L4)3](BF4)‚H2O}n (10). The 3D
structure of 10 is constructed by a 2D inorganic [(Cu6I5)+]n
layer connected by ligand L4 through nitrogen and sulfur
atoms. Interestingly, the [(Cu6I5)+]n layer is built by inter-
secting 1D [CuI]n right-handed helices (Figure 9a, b) in three
different directions, effectively forming an undulating
pseudohexagonal net. Because the helical network in the
(6,3)-topology net is right-handed, the net as a whole in this
case is known as being right-handed. Alternate inorganic
[(Cu6I5)+]n lamellae and organic thioether ligand L4 layers,
expressed as an ABAB repeating pattern, extend to form a
3D network (Figure 9c). Disordered water molecules and
BF4- anions fill in the network. A discussion of the structure
detail was given in our recent communication.8
Conclusion
The self-assembly of flexible pyrimidine-based thioether
ligands L1-L4 and copper(I) halides or pseudo-halides
Photoluminescence Properties. Complexes 1-10 are
stable in air. Complexes 1-3 do not exhibit detectable
emission, whereas 4-10 show strong photoluminescence
(25) (a) Araki, H.; Tsuge, K.; Sasaki, Y.; Ishizaka, S.; Kitamura, N. Inorg.
Chem. 2005, 44, 9667. (b) Ford, P. C.; Cariati, E.; Bourassa, J. Chem.
ReV. 1999, 99, 3625.
Inorganic Chemistry, Vol. 45, No. 10, 2006 4045

Peng et al.
Chart 2. Schematic Illustration of Complexes 3-10a
effects in these complexes; this also leads to the soft Cu(I)
center tending to coordinate to N donors rather than S donors.
Three CuI complexes of L2-L4 provide considerable
evidence to support the contention that ligand geometry
influences the formation of metal-ligand frameworks.
To be worthy of comparison, iodide adducts 3, 4, and 8
bear significant difference. This may be attributed to the
differences in the bite angles of the three corresponding
ligands, with the disposition of their lone pairs varying from
acute (bridging angle 60°, as in L2) through obtuse (bridging
angle 120°, as in L3) to linear (bridging angle 180°, as in
L4), though this kind of geometry effect of flexible ligands
is considerably weakened when comparing rigid ligands,
because of the free rotation of the S-CH2 arm.
On the other hand, the changes in counterion also cause
certain geometrical differences, as is the case in 7-9. Three
different 1D copper halide or pseudo-halide frameworks,
zigzag chain, stair, displaced stair, are found, respectively,
in the three complexes and are further connected through
the bridging flexible ligand to construct a two-dimensional
layer network. The structural variety of these 1D frameworks
may be attributed to the differences in coordination properties
of the incorporated counteranions µ3-I-, µ-CN-, and 1,1,3-
µ3-SCN-. It must be mentioned that although it uses the
same ligand, the 3D polymer 10 is a surprising contrast to
the two-dimensional networks in 7-9.8 Both types of iodide
anion (µ3-I and µ2-I) are incorporated into the [Cu6I5]+ layer
in 10, as well as the capsulated BF- anion, which may act
as a template of the coordination polymer and effectively
balance the charge of [Cu6I5]+ layer. This further demon-
strates the significant role of the anion in the preparation
and structures.
The set of structures exemplifies the influence of various
factors such as ligand geometry, the nature of the anions,
and π-π stacking on the self-assembly of diverse coordina-
tion aggregates with Cu(I) salts. This work offers the
possibility to control the formation of such network structures
by varying those factors.
Acknowledgment. The authors gratefully acknowledge
the financial support provided by the National Natural
Science Foundation of China (20571050 and 20271031) and
the Natural Science Foundation of Guangdong Province of
China (021240).
forms a series of complexes from discrete molecules to
extended architectures with increasing dimensionality, as
schematically shown in Chart 2. The structural differences
of oligomers of 1 and 2 and polymers of 4 and 5 can be
explained by the one noncoordinated C atom in central
benzene of L3 being replaced by a strong donor N atom of
L1, which resulted in the SNS chelating coordination moiety
in 1 and 2. Excerpt for in 10, there are no significant Cu-S
interactions found in 1-9, which may be due to the
geometrical effects being more preferential than electronic
Supporting Information Available: Crystallographic files
in cif format and supplementary illustration for the structures.
This material is available free of charge via the Internet at
http://pubs.acs.org.
IC060074X
4046 Inorganic Chemistry, Vol. 45, No. 10, 2006