Syntheses and characterizations of six hydrogen-bonded silver(I) complexes from assembly of silver(I) nitrate and aminobenzoic acid

Article abstract of DOI:10.1016/S0020-1693(03)00487-0

Six hydrogen-bonded silver(I) complexes, Ag(4-abaH)₂(NO ₃) (1), [Ag(4-abaH)₂(NO₃)]_n (2), {[Ag(4-aba)(4-abaH)]·H₂O}_n (3), {[Ag(4,4 ^′-bipy)(H₂O)](4-aba)_0.5(NO ₃)_0.5·(H₂O)_0.5}_n (4), [Ag[(3-abaH_0.5)₂] (5), and {[Ag(3-aba)]·H ₂O}_n (6) (4-abaH=4-aminobenzoic acid, 3-abaH=3- aminobenzoic acid), have been synthesized and characterized by single-crystal X-ray diffraction analyses. In 1, 4-abaH serves as a monodentate ligand coordinating to Ag(I) through its nitrogen atom, while uncoordinated carboxylic group links (4-abaH)-Ag-(4-abaH) into a one-dimensional metallic carboxylic synthon. 2 may be regarded as an extension of 1 into a two-dimensional carboxylic synthon through NO₃^- bridging two adjacent Ag(I) centers. In 3, 4-abaH in a monodentate mode and 4-aba in a μ-N,O bridging mode link three-coordinated Ag(I) to form a one-dimensional swallow-like chain, which is further extended into a two-dimensional layer structure through inter-chain hydrogen bonding interactions. The alternating Ag(I) and 4,4^′-bipy in 4 give rise to a slightly distorted linear chain, which is further extended into a two-dimensional layer through the completely overlapping and off-set stacking interactions. The hydrogen bonds involving in weakly coordinated aqueous molecules and 4-aba further extend it into a three-dimensional framework. In 5, the inter-molecular hydrogen bonding and π-π stacking interactions extend Ag[(3-abaH _0.5)₂] into a two-dimensional supramolecular architecture. In 6, 3-aba in a μ₃-N,O,O^′ coordination mode links three three-coordinated Ag(I) into a two-dimensional network. Uncoordinated aqueous molecules and the adjacent 3-aba oxygen atoms form intermolecular hydrogen bonds.

Full text of DOI:10.1016/S0020-1693(03)00487-0

Inorganica Chimica Acta 357 (2004) 103–114
www.elsevier.com/locate/ica
Syntheses and characterizations of six hydrogen-bonded
silver(I) complexes from assembly of silver(I) nitrate
and aminobenzoic acid
*
Ruihu Wang, MaoChun Hong , Junhua Luo, Feilong Jiang, Lei Han,
Zhenzhong Lin, Rong Cao
State Key Laboratory of Structural Chemistry, Fujian Institute of the Research on the Structure of Matter,
Chinese Academy of Sciences, Fuzhou, 155 YangQiaoXiLu, Fuzhou, Fujian 350002, China
Received 30 April 2003; accepted 19 July 2003
Abstract
Six hydrogen-bonded silver(I) complexes, Ag(4-abaH)2(NO3) (1), [Ag(4-abaH)2(NO3)]n (2), {[Ag(4-aba)(4-abaH)] ꢀ H2O}n (3),
{[Ag(4,40-bipy)(H2O)](4-aba)0:5(NO3)0:5 ꢀ (H2O)0:5
}
(4), [Ag[(3-abaH0:5)2] (5), and {[Ag(3-aba)] ꢀ H2O}n (6) (4-abaH ¼ 4-amino-
n
benzoic acid, 3-abaH ¼ 3-aminobenzoic acid), have been synthesized and characterized by single-crystal X-ray diffraction analyses.
In 1, 4-abaH serves as a monodentate ligand coordinating to Ag(I) through its nitrogen atom, while uncoordinated carboxylic group
links (4-abaH)-Ag-(4-abaH) into a one-dimenꢁsional metallic carboxylic synthon. 2 may be regarded as an extension of 1 into a two-
dimensional carboxylic synthon through NO3 bridging two adjacent Ag(I) centers. In 3, 4-abaH in a monodentate mode and 4-aba
in a l-N,O bridging mode link three-coordinated Ag(I) to form a one-dimensional swallow-like chain, which is further extended into
a two-dimensional layer structure through inter-chain hydrogen bonding interactions. The alternating Ag(I) and 4,40-bipy in 4 give
rise to a slightly distorted linear chain, which is further extended into a two-dimensional layer through the completely overlapping
and off-set stacking interactions. The hydrogen bonds involving in weakly coordinated aqueous molecules and 4-aba further extend
it into a three-dimensional framework. In 5, the inter-molecular hydrogen bonding and p–p stacking interactions extend Ag[(3-
abaH0:5)2] into a two-dimensional supramolecular architecture. In 6, 3-aba in a l3-N,O,O0 coordination mode links three three-
coordinated Ag(I) into a two-dimensional network. Uncoordinated aqueous molecules and the adjacent 3-aba oxygen atoms form
intermolecular hydrogen bonds.
Ó 2003 Elsevier B.V. All rights reserved.
Keywords: Silver(I) complexes; Hydrogen bonds; Synthesis; Crystal structure
1. Introduction
teraction and their combination. The increasing interest
in this field is justified not only by the intellectual
challenge in controlling and manipulating self-assembly
process, but also by their fascinating structural diversi-
ties and potential application in functional materials,
nanotechnology, and biological recognition [3–5]. So far
a large number of one-, two-, and three-dimensional
metal-organic frameworks have been designed and
constructed through metal ions recognizing the infor-
mation stored in the ligands according to the algorithm
defined by their coordination geometry. The assembly
process of these frameworks is highly influenced by lot
of factors, such as the coordination nature of metal ions,
the structural characterization of organic ligands,
Design and syntheses of organic and metal-organic
compounds with unusual and tailorable structures are
fundamental steps to discover and fabricate various
functional supramolecular devices or technologically
useful materials [1,2]. There has recently been much in-
terest and progress in the study of crystal engineering of
supramolecular architectures organized and sustained
by means of covalent bonds, hydrogen bonds, p–p in-
* Corresponding author. Tel.: +865913792460; fax: +86-591-
3714946.
E-mail address: hmc@ms.fjirsm.ac.cn (MC. Hong).
0020-1693/$ - see front matter Ó 2003 Elsevier B.V. All rights reserved.
doi:10.1016/S0020-1693(03)00487-0

104
R. Wang et al. / Inorganica Chimica Acta 357 (2004) 103–114
solvent system, temperature, pH value of the solution,
the ratio of metal to ligand, template, and counter ions
[6–8]. Sometimes, a subtle alteration in any of these
factors can result in new complexes with different
structural topologies and different functions. Thus,
modification and conversion of supramolecular com-
plexes may be controlled and tuned through changing
their effect factors. However, there has been a scarcity of
information on supramolecular reactions, featuring the
well-defined conversion of supramolecular complexes,
because factors influencing the self-assembly process are
still not clearly understood [8]. The exploration of syn-
thetic strategies and routines is therefore a long-term
challenge, and a great deal of work is required to extend
the knowledge of relevant structural types and establish
proper synthetic strategies leading to desirable supra-
molecular species. For instance, Lehn and co-workers
discovered the sequential formation of linear and cir-
cular helicates as a result of kinetic and thermodynamic
action, respectively [9]. Wright and co-workers [5a] re-
vealed that solid-state transformation of Zn(II) 1,4-
benzenedicarboxylate complexes may be mediated by
hydrogen-bond-forming molecules. Some pH-dependent
self-assembly process resulting in the interconversion of
different complexes has recently been reported [10].
In previous researches, we have employed a series of
versatile organic ligands containing nitrogen and sulfur
donor atoms and coordinatively flexible Ag(I) for su-
pramolecular assembly and obtained a series of novel
supramolecular complexes [11]. These complexes have
been synthesized by the direct reaction of metal ions and
organic ligands under different reaction conditions and
have not exhibited switching abilities. Considering that
carboxylic group ligands might adopt various coordi-
nate modes and proton in carboxylic acid ligands might
be controlled through adjusting pH value of reaction
system, we have extended our works through employing
multifunctional organic ligands, such as 4-aminobenzoic
acid [12a] and 4-aminosalicylate [12b], which might form
coordination covalent bonds and hydrogen bonds, as
building blocks. Assembly of ligands containing nitro-
gen atoms and carboxylic groups with metal ions own-
ing good affinity for coordination atoms of ligands, such
as Ag(I), Cd(II) and Pd(II), is inclined to form molec-
ular complexes with head-to-head carboxylic acid hy-
drogen bonds. These molecular complexes may be used
as precursors for further reaction by breaking hydrogen
bonding interaction using bases, such as NaOH, KOH,
NH3, N(Et)3, and pyridine, and assembly anew of pre-
cursors may lead to new complexes with different
structural topologies and functional properties. Ag(I)
complexes derived from 4-aminobenzoic acid [13] and 3-
aminobenzoic acid [14] have been investigated previ-
ously, but those obtained through adjusting proton in
carboxylic acid ligands have seldom been reported.
Herein, we report syntheses and crystal structures of a
series of Ag(I) complexes from 4-aminobenzoic acid,-
Ag(4-abaH)2(NO3) (1), [Ag(4-abaH)2(NO3)]n (2), {[Ag
(4-aba)(4-abaH)] ꢀ H2O}n (3), {[Ag(4,40-bipy)(H2O)](4-
aba)0:5(NO3)0:5 ꢀ (H2O)0:5}n (4), as well as two complexes
from 3-aminobenzoic acid, Ag[(3-aba)2H] (5), {[Ag(3-
aba)] ꢀ H2O}n (6). Compound 3 can be produced from 1
and 2 in the presence of NH3 and complex 6 can be
obtained from complex 5 in the presence of NH3 or
NaOH, but both reversible reactions of inter-conversion
were not successful (Schemes 1, 2).
Scheme 2. The preparation of Ag(I) compounds from 3-abaH (p-
Tos ¼ p-toluenesulfonate).
14(a)
[Ag2(4-aba)2]n
14(b)
[Ag(4-aba)]n
Ag(4-aba)(hmt)H2O 14(c)
hmt/NH3
KOH
NaOH
NaOH
14(d)
Ag(pTos)
[Ag(pTos)(4-abaH)]n
Ag(4-abaH)2(NO3) 1
4-abaH + AgNO3
NH3 (1:1)
4,4’-bipy/NH3
{{[Ag(4,4’-bipy)(H2O)](4-aba)
0.5(NO3)0.5(H2O)0.5
NH3
NH3
NaOH
}
4
n
{[Ag(4-aba)(4-abaH)](H2O}n 3
[Ag(4-abaH)2(NO3)]n
2
Scheme 1. The preparation of Ag(I) compounds from 4-abaH (hmt ¼ hexamethylenetetramine, p-Tos ¼ p-toluenesulfonate).

R. Wang et al. / Inorganica Chimica Acta 357 (2004) 103–114
105
2. Experimental
added to a solution of AgNO3 (0.04 g, 0.25 mmol) in
CH3CN (10 ml) and H2O (10 ml), the mixture was
dissolved by dropwise a 25% aqueous NH3 solution (0.5
ml). The resulting solution was filtrated and kept in air
for two weeks at room temperature, the colorless crys-
tals of 3 suitable for X-ray diffraction were obtained.
(Yield: 0.06 g, 60.13%.)
2.1. General
All reagents were commercially available and used as
purchased without further purification. The IR spectra
as KBr disk were recorded on a Magna 750 FT-IR
spectrophotometer. Elemental analyses were determined
on an Elementar Vario ELIII elementary analyzer by
elemental analysis group of this Institute.
{[Ag(4,40-bipy)(H2O)](4-aba)0:5(NO3)0:5 ꢀ (H2O)0:5
}
n
(4). A solution of AgNO3 (0.09 g, 0.5 mmol) in CH3CN
(10 ml) was added to a stirring solution of 4-abaH (0.07 g,
0.5 mmol) in H2O (5 ml), followed by the addition of a
solution of 4,40-bipy (0.08 g, 0.5 mmol) in H2O (2 ml). The
mixture was stirred for 10 min and then added dropwise a
25% aqueous NH3 solution (0.5 ml). The resulting solu-
tion was filtered and kept in air for six days at room
temperature, light yellow crystals of 4 suitable for X-ray
diffraction were obtained. (Yield: 0.10 g, 51.28% based on
4,40-bipy.) Anal. Calcd for C13:5H14AgN3O4 (390.15): C
41.52, H 3.59, N 10.77; found: C 41.57, H 3.64, N 10.81%.
IR (KBr pellet): 3427 (m), 3336 (m), 3049 (w), 1622 (m),
1599 (s), 1579 (m), 1533 (s), 1489 (vw), 1412 (s), 1385 (vs),
1313 (w), 1219 (w), 1176 (w), 1136 (vw), 1066 (vw), 1003
(vw), 852 (w), 802 (s), 727 (vw), 627 (w), 507 (vw), 488
(vw).
Ag[(3-aba)2H] (5). The procedure is similar to
synthesis of complex 2 except that 3-abaH was used
instead of 4-abaH. (Yield: 0.07 g, 73.64%.) Anal. Calcd
for C7H6:5Ag0:5NO2 (190.57): C 44.12, H 3.41, N 7.35;
found: C 44.17, H 3.48, N 7.37%. IR (KBr pellet): 3408
(s), 3336 (m), 3207 (m), 3107 (m), 1633 (s), 1608 (s), 1591
(s), 1562 (s), 1491 (w), 1456 (m), 1385 (vs), 1317 (m),
1263 (w), 1203 (vw), 1134 (w), 1111 (w), 1076 (vw), 910
(w), 827 (w), 791 (m), 760 (s), 679 (m), 663 (m), 553 (w),
499 (w).
{[Ag(3-aba)] ꢀ H2O}n (6). The procedure is similar to
synthesis of complex 3 except that 3-abaH was used in-
stead of 4-abaH. (Yield: 0.08 g, 61.07%.) Anal. Calcd for
C7H8AgNO3 (262.01): C 32.09, H 3.05, N 5.34; found: C
32.12, H 3.07, N 5.38%. IR (KBr pellet): 3420 (s, br), 1626
(s), 1593 (s), 1556 (vs), 1510 (w), 1450 (m), 1389 (vs), 1317
(w), 1263 (w), 1165 (vw), 1110 (vw), 1072 (vw), 997 (vw),
891 (vw), 773 (s), 687 (m), 675 (m), 536 (w).
Compound 6 can also be obtained through the fol-
lowing procedure: compound 5 (0.05 g, 0.25 mmol) was
added to a solution of AgNO3 (0.04 g, 0.25 mmol) in
CH3CN (10 ml) and H2O (10 ml), the mixture was
dissolved by dropwise a 25% aqueous NH3 solution (0.5
ml). The resulting solution was filtrated and kept in air
for about two weeks, the colorless crystals of 6 suitable
for X-ray diffraction were obtained. (Yield 0.03 g,
45.80%.)
2.2. Syntheses
Ag(4-abaH)2(NO3) (1). A solution of AgNO3 (0.09
g, 0.5 mmol) in CH3CN (10 ml) was slowly added to a
stirring solution of 4-abaH (0.07 g, 0.5 mmol) in H2O (5
ml). The resulting solution was kept in air for four days
at room temperature, colorless crystals of 1 suitable for
X-ray diffraction were obtained. (Yield: 0.10 g, 90.07%
based on 4-abaH.) Anal. Calcd for C14H14AgN3O7
(444.16): C, 37.86, H 3.15, N 9.47; found: C 37.91, H
3.17, N 9.45%. IR (KBr pellet): 3457 (m), 3381 (m), 3363
(m), 2974 (w), 2671 (w), 2548 (w), 1664 (s), 1637 (s), 1624
(s), 1603 (s), 1574 (m), 1522 (w), 1443 (m), 1421 (s), 1385
(vs), 1343 (vw), 1327 (m), 1311 (m), 1288 (s), 1174 (m),
1130 (w), 1090 (vw), 912 (vw), 843 (w), 771 (m), 696
(vw), 615 (w), 552 (vw), 498 (vw).
[Ag(4-abaH)2(NO3)]n (2). A solution of AgNO3
(0.09 g, 0.5 mmol) in CH3CN (10 ml) was added to a
solution of 4-abaH (0.07 g, 0.5 mmol) in H2O (5 ml),
then a 25% aqueous NH3 solution (0.04 ml, 0.5 mmol)
was added dropwise to the stirring reaction mixture. The
resulting solution was kept in air for six days at room
temperature, colorless crystals of 2 suitable for X-ray
diffraction were obtained. (Yield: 0.07 g, 63.04% based
on 4-abaH.) Anal. Calcd for C14H14AgN3O7 (444.16): C
37.86, H 3.15, N 9.47; found: C 37.87, H 3.18, N 9.49%.
IR (KBr pellet): 3457 (m), 3383 (m), 3363 (m), 2974 (w),
2675 (w), 2551 (w), 1664 (s), 1637 (s), 1626 (s), 1603 (s),
1574 (m), 1524 (w), 1443 (m), 1421 (s), 1385 (vs), 1342
(w), 1327 (s), 1311 (s), 1288 (s), 1174 (s), 1130 (w), 1076
(vw), 914 (vw), 843 (m), 771 (m), 698 (vw), 621 (w), 552
(vw), 499 (w).
{[Ag(4-aba)(4-abaH)] ꢀ H2O}n (3). The procedure
is similar to synthesis of complex 2 except that a 0.5 ml
of 25% aqueous NH3 solution was used instead of 0.04
ml. (Yield: 0.05 g, 50.11% based on 4-abaH.) Anal.
Calcd for C14H15AgN2O5 (399.15): C 42.12, H 3.76, N
7.01; found: C 42.13, H 3.81, N 7.06%. IR (KBr pellet):
3334 (m, br), 3064 (w), 2657 (w), 2214 (w), 1674 (w),
1647 (s), 1610 (s), 1591 (s), 1529 (s), 1431 (m), 1398 (s),
1288 (m), 1263 (w), 1174 (m), 1136 (w), 1082 (w), 1011
(vw), 945(vw), 852 (m), 781 (m), 694 (m), 621 (w), 529
(vw), 496 (w).
2.3. X-ray crystallography
Compound 3 can also be obtained through the fol-
lowing procedure: compound 1 (0.11 g, 0.25 mmol) was
Intensity data for complexes 1–4 and 6 were mea-
sured on a Siemens Smart CCD diffractometer with

106
R. Wang et al. / Inorganica Chimica Acta 357 (2004) 103–114
graphite-monochromated Mo Ka radiation (k ¼
3. Results and discussion
ꢀ
0:71073 A) at room temperature. Intensity data for 5
were measured on a CAD4 four-circle diffractometer
with graphite-monochromated Mo Ka radiation
3.1. Syntheses and characterization
ꢀ
(k ¼ 0:71073 A) at 298 K. Empirical absorption cor-
Treatment of potassium 4-aminobenzoate (4-aba)
with AgNO3 in a 1:1 molar ratio in H2O/acetone, and
sodium 4-aba with AgNO3 in a 1:1 molar ratio in H2O/
CH3CN has resulted in the formation of acetone solvate
[Ag2(4-aba)2]n [13a] and [Ag(4-aba)]n [13b], respectively.
However, reaction of silver(I) p-toluenesulfonate (p-Tos)
and 4-abaH in a 1:1 molar ratio in EtOH has produced
[Ag(p-Tos)(4-abaH)]n [13d], in which 4-abaH acts as a
monodentate ligand coordinating to Ag(I) through its
nitrogen atom, the remaining carboxylic group neither
takes part in coordination nor forms carboxylic acid
hydrogen bonds. Thus, it would be interesting to pre-
pare a series of Ag(I) compounds by controlling the
carboxylic group of 4-abaH since Ag(I) possesses flexi-
ble coordination geometry and deprotonated 4-aba
could adopt various coordination modes (Scheme 3). A
straightforward reaction of 4-abaH and AgNO3 in a 1:1
molar ratio in H2O/CH3CN afforded compound 1
rections were applied by using the SADABS program
for the Siemens area detector. The structures were
solved by direct methods and all calculations were
performed through using the SHELXL-97 program.
The coordinate of Ag was obtained from an E-map,
successive difference Fourier syntheses gave all the
coordinates of the non-hydrogen atoms. The struc-
tures were refined by full-matrix least-squares mini-
P
2
mization of
parameters for all atoms except the H atoms. The
positions of H atoms were generated geometrically
ðFo ꢁ FcÞ with anisotropic thermal
ꢀ
(C–H bond fixed at 0.96 A), assigned isotropic ther-
mal parameters, and allowed to ride on their parent
carbon atoms before the final cycle of refinement.
Table 1 gives structure determination summary for 1–
6 and Table 2 lists the selected bond lengths and
angles for 1–6.
Table 1
Crystallographic data for the six crystal structures
Compound
1
2
3
4
5
6
Formula
Fw
C14H14AgN3O7
444.16
C14H14AgN3O7
444.16
C14H15AgN2O5
399.15
C13:5H14AgN3O4
390.15
C7H6:5Ag0:5NO2
190.57
C7H8AgNO3
262.01
Crystal size (mm) 0.26 ꢂ 0.16 ꢂ 0.06 0.58 ꢂ 0.30 ꢂ 0.06 0.76 ꢂ 0.22 ꢂ 0.10 0.66 ꢂ 0.54 ꢂ 0.34 0.27 ꢂ 0.15 ꢂ 0.09 0.32 ꢂ 0.20 ꢂ 0.14
Crystal system
Space group
monoclinic
P2/c
orthorhombic
Pcca
monoclinic
P2(1)/n
monoclinic
P2(1)/m
triclinic
P-1
monoclinic
P2(1)/c
ꢀ
a (A)
4.8436(7)
5.7309(8)
28.691(4)
28.103(3)
4.5857(5)
11.7914(11)
9.0672(7)
18.0245(14)
9.3905(7)
8.2979(2) A
17.5765(1)
9.9688(1)
6.205(3)
6.958(3)
7.827(2)
79.83(3)
74.79(3)
74.24(3)
311.8(2)
2
8.0022(8)
16.9508(16)
5.8745(6)
ꢀ
b (A)
ꢀ
c (A)
b (°)
92.986(3)
103.678(2)
103.506(1)
96.895(2)
3
ꢀ
V (A )
795.3(2)
2
1.855
1519.6(3)
4
1.941
1491.2(2)
4
1.778
1413.72(4)
4
1.833
791.08(14)
4
Z
Dc (g cmꢁ3
l (mmꢁ1
Diffractometer
)
2.030
1.635
2.200
2.509
)
1.312
1.373
1.377
1.447
Siemens Smart
CCD
444
Siemens Smart
CCD
888
Siemens Smart
CCD
800
Siemens Smart
CCD
780
CAD4 four-circle Siemens Smart
CCD
F ð000Þ
T (K)
190
512
293(2)
0.71073
2598
293(2)
0.71073
4259
293(2)
0.71073
5297
293(2)
0.71073
4886
293(2)
0.71073
1318
293(2)
0.71073
2476
ꢀ
k(Mo Ka) (A)
Reflections
collected
Unique reflections 1397
1350
119
2608
202
2562
223
1223
98
1370
109
Parameters
Goodness-of-fit
on F 2
R1; wRðI > 2rðIÞÞ
R1; wR (all data)b
Dqmin and Dqmax
131
1.028
1.117
1.031
1.036
1.131
1.130
a
0.0587, 0.1466
0.1139, 0.1958
0.447 and )0.841
0.0391, 0.1050
0.0611, 0.1356
0.387 and )1.022
0.0425, 0.1021
0.0650, 0.1154
0.834 and )0.896
0.0282, 0.0731
0.0359, 0.0766
0.505 and )0.567
0.0451, 0.1040
0.0513, 0.1071
1.027 and )1.527
0.0580, 0.1387
0.0711, 0.1513
0.786 and )1.826
ꢁ3
ꢀ
(e A
)
P
P
a R ¼ jjFoj ꢁ jFcjjÞ= jFcj.
P
P
2
b wR ¼ ½ wðFo2 ꢁ Fc2Þ = wðFo2Þ.

R. Wang et al. / Inorganica Chimica Acta 357 (2004) 103–114
107
Table 2
ꢀ
Selected bond lengths [A] and angles [°] for the six complexes
Complex 1
Ag–N
O(2)–C(1)
2.236(6)
1.265(8)
152.0(4)
123.1(6)
O(1)–C(1)
N–C(5)
C(5)–N–Ag
1.273(8)
1.416(8)
117.0(5)
N–Ag–N(0A)
O(2)–C(1)–O(1)
Complex 2
Ag–N
Ag–O(11)
2.233(3)
2.581(4)
O(1)–C(1)
O(2)–C(1)
1.229(5)
1.307(5)
N–C(5)
1.418(6)
146.4(2)
N–Ag–N(0A)
N–Ag–O(11)
N(0A)–Ag–O(11)
N–Ag–O(11A)
O(11)–Ag–O(11A)
C(5)–N–Ag
O(1)–C(1)–O(2)
95.6(3)
116.9(3)
122.4(4)
96.29(14)
106.17(15)
106.17(15)
Complex 3
Ag–N(1A)
2.285(4)
2.323(3)
1.434(6)
1.231(6)
1.306(6)
128.36(15)
108.47(14)
109.6(3)
122.2(5)
Ag–N(2)
2.305(5)
1.427(5)
1.252(6)
1.214(6)
Ag–O(12)
N(2)–C(25)
N(1)–C(15)
O(11)–C(11)
O(21)–C(21)
O(12)–C(11)
O(22)–C(21)
N(1A)–Ag–N(2)
N(2)–Ag–O(12)
C(25)–N(2)–Ag
O(21)–C(21)–O(22)
N(1A)–Ag–O(12)
C(15)–N(1)–AgB
O(12)–C(11)–O(11)
121.10(15)
117.8(3)
122.8(5)
Complex 4
Ag–N(1)
Ag–O(2W)
2.146(3)
2.695(3)
1.265(6)
173.45(10)
90.81(9)
Ag–N(2A)
N(11)–C(15)
2.151(2)
1.373(7)
1.241(6)
92.71(9)
123.8(5)
O(11)–C(11)
N(1)–Ag–N(2A)
N(2A)–Ag–O(2W)
O(12)–C(11)
N(1)–Ag–O(2W)
O(12)–C(11)–O(11)
Complex 5
Ag–N
N–C(4)
2.135(4)
1.433(6)
1.285(6)
180.0
Ag–N(0A)
O(1)–C(1)
2.135(4)
1.232(6)
O(2)–C(1)
N–Ag–N(0A)
O(1)–C(1)–O(2)
C(4)–N–Ag
115.4(3)
123.7(4)
Complex 6
Ag–O(1)
2.204(6)
2.529(6)
2.9484(3)
1.250(10)
158.9(3)
99.9(2)
Ag–N(0B)
Ag–AgA
2.215(7)
Ag–O(2D)
Ag–AgD
O(1)–C(1)
2.9484(3)
1.442(10)
1.269(10)
100.2(2)
N–C(4)
O(2)–C(1)
O(1)–Ag–N(0B)
N(0B)–Ag–O(2D)
N(0B)–Ag–AgA
O(1)–Ag–AgD
O(2D)–Ag–AgD
C(1)–O(1)–Ag
O(1)–C(1)–O(2)
O(1)–Ag–O(2D)
O(1)–Ag–AgA
O(2D)–Ag–AgA
N(0B)–Ag–AgD
AgA–Ag–AgD
C(1)–O(2)–AgA
92.60(18)
125.08(15)
106.66(18)
170.01(5)
123.8(6)
81.05(18)
77.94(17)
60.74(15)
107.5(5)
122.6(8)
Symmetry codes: 1 (A) ꢁx þ 1; y; ꢁz þ 1=2; 2 (A) ꢁx þ 3=2; ꢁy ꢁ 2; z; 3 (A) ꢁx þ 1=2; y þ 1=2; ꢁz þ 3=2; (B) ꢁx þ 1=2; y ꢁ 1=2; ꢁz þ 3=2;
4 (A) x þ 1; y; z þ 1; 5 (A) ꢁx; ꢁy; ꢁz; 6 (A) x; ꢁy þ 1=2; z ꢁ 1=2; (B) ꢁx; y þ 1=2; ꢁz þ 1=2; (D) x; ꢁy þ 1=2; z þ 1=2.
formed by head-to-head carboxylic acid hydrogen
bonds linking mononuclear Ag(4-abaH) (Scheme 1f).
When equal stoichiometric ratio NH3 and a large
amount of NH3 have been employed as base under the
same reaction conditions, compound 2, formed by head-
to-head carboxylic acid hydrogen bonds linking linear
Ag(4-abaH)(NO3) chains, and compound 3, formed
through 4-abaH (Scheme 3b) and 4-aba (Scheme 3d)
linking three-coordinated Ag(I), have been obtained,
respectively. Use of 4-abaH, AgNO3, and 4,40-bipy in a
1:1:1 molar ratio in the presence of a larger amount of
NH3 produced compound 4, in which 4-aba acts as
counter anions and the linkers of adjacent [Ag(4,40-
bipy)]n. The successful isolation of compounds 1–4
prompts us to investigate switching ability from 1 and 2
to the other Ag-(4-aba) complexes through controlling

108
R. Wang et al. / Inorganica Chimica Acta 357 (2004) 103–114
O
O
NH2
NH2
O
Ag
H
HO
(a)
A
Ag
(b)
Ag
NH2
O
O
Ag
NH2
O
O
Ag
(c)
(d)
H
Ag
Ag
O
O
O
O
H2N
NH2
NH2
O
O
Ag
Ag
Ag
H
Ag
(e)
(f)
Scheme 3. The possible coordination modes of 4-abaH and 4-aba, A ¼ hydrogen bonding acceptor.
pH value of reaction system. When using compound 1
as a starting material in the presence of a larger amount
of NH3 and NaOH in H2O/CH3CN afforded compound
3 and [Ag(4-aba)]n [13b], respectively, judged from their
similar crystal structural values and IR spectra (see
Section 2). The attempt to switch from 1 to 2, 4, and
acetone solvate [Ag2(4-aba)2]n [13a] was unsuccessful,
and the same result was found when using compound 2
as a starting materials. This exhibits compound 1 and 2
can act as the precursors of 3 and [Ag(4-aba)]n [13b]
(Scheme 1).
Compound 5 was obtained by reaction of 3-abaH
and AgNO3 in a 1:1 molar ratio in the H2O/CH3CN in
presence of equal stoichiometric ratio NH3. Different
from the synthesis of Ag-(4-aba) compounds, when us-
ing a larger amount of NH3 or suitable NaOH as base,
the same compound 6 was obtained in a good yield.
Compound 5 may be also employed as precursor of
compound 6 in the presence of a larger amount of NH3
or NaOH (Scheme 2).
3.2. Structures
Ag(4-abaH)2(NO3) (1). Single crystal X-ray dif-
fraction analysis reveals that compound 1 consists of (4-
abaH)-Ag-(4-abaH) metallic synthons and disordered
NO3ꢁ. As shown in Fig. 1, Ag(I) is in a highly distorted
linear geometry and is coordinated by two nitrogen at-
ꢀ
oms from different 4-abaH [Ag–N ¼ 2.236(6) A, N–Ag–
N(0A) ¼ 152.0(4)°]. Each 4-abaH acts as a monodentate
ligand coordinating to Ag(I) center through its nitrogen
atom and forms hydrogen bonds through the carboxylic
groups (Scheme 3f). The dihedral angle of two 4-abaH
attached to Ag(I) center is 50.6°. However, in [Ag(p-
Tos)(4-abaH)]n [13d], uncoordinated carboxylic group
has not formed any hydrogen-bonding interaction ow-
ing to the effect of p-Tos (Scheme 3a). Each pair of
carboxylic acid from adjacent Ag(4-abaH)2 forms a
head-to-head eight-membered hydrogen bonding ring
[R22ð8Þ in graph set notation] [16] which may be regarded
as a supramolecular synthon [O(1)–H ꢀ ꢀ ꢀ O(2)i 2.615(7)
ꢀ
The pKa values of 3-abaH and 4-abaH are 4.9 and
4.7, [15] respectively, showing that the relative base
strength for their Lewis bases is probably not important
to their coordination ability to Ag(I), stereochemistry of
ligands plays a crucial role in the formation of their
Ag(I) complexes. Thus, assembly of 3-abaH and 4-abaH
with Ag(I) under the same reaction conditions can result
in different structural architectures.
A; symmetry code: (i) ꢁx ꢁ 1; ꢁy; ꢁz]. Two adjacent 4-
abaH in the synthon are approximately coplanar with a
ꢀ
mean deviation of 0.0115 A. The hydrogen bonds extend
the Ag(4-abaH)2 into a one-dimensional stair-like
structure. There are no short contacts or noteworthy
aryl–aryl interaction between adjacent chains. To our
knowledge, supramolecular synthons involved in head-
to-head carboxylic acid hydrogen bonds have well been
ꢁ
Fig. 1. One-dimensional hydrogen bonding chain in 1 with uncoordinated NO3 omitted for clarity.

R. Wang et al. / Inorganica Chimica Acta 357 (2004) 103–114
109
documented in previous works, [12a,16] but the car-
boxylic synthons of Ag(I) have seldom been reported
owing to its strong coordination ability and flexible
coordination geometry.
ꢁx þ 1; ꢁy; ꢁz] [17]. The hydrogen-bonding interac-
tion extends one-dimensional chains into an infinite two-
ꢀ
dimensional network structure with the 17.6 ꢂ 4.6 A
internal dimension. There are no short contacts or note-
worthy aryl–aryl interaction between adjacent chains or
neighboring layers.
[Ag(4-abaH)2(NO3)]n (2). Compound 2 is made up
of 4-abaH ligands attached to silver(I)-nitrate chain
running along the a-axis. As shown in Fig. 2(a), each
Ag(I) is in a distorted tetrahedral geometry and is co-
ordinated by two nitrogen atomsꢁfrom 4-abaH and two
{[Ag(4-aba)(4-abaH)] ꢀ H2O}n (3). Single crystal
X-ray diffraction analysis reveals that complex 3 consists
of one-dimensional swallow-like chains and lattice
aqueous molecules. The carboxylic proton of 4-abaH is
generated from successive difference Fourier syntheses
in solving the structure. As shown in Fig. 3(a), each
Ag(I) center is in a slightly distorted Y-shaped envi-
ronment and is coordinated by a nitrogen atom from
4-abaH, a nitrogen atom and an oxygen atom from
different 4-aba [N(1A)–Ag–N(2) 128.36(15), N(1A)–
Ag–O(12) 121.10(15), N(2)–Ag–O(12) 108.47(14)°].
ꢀ
oxygen atoms from different NO3 [Ag–N ¼ 2.233(3) A;
ꢀ
Ag–O(11) ¼ 2.581(4) A]. The dihedral angle of two 4-
abaH attached to Ag(I) center and bond angle of N–
Ag–N(0A) are 36.0° and 146.4(2)°, respectively, which
are smaller than those in 1, this is probably ascribed to
ꢁ
bridging interaction of NO3 between two adjacent
Ag(I) centers. Each pair of adjacentꢁAg(I) centers is
bridged by two oxygen atoms of NO3 to form a one-
dimensional silver(I)-nitrate chain with Agꢀ ꢀ ꢀAg sepa-
ꢀ
Ag–NabaH bond distance of 2.305(5) A is longer than
ꢀ
ꢀ
Ag–Naba bond distance of 2.285(4) A, C–NabaH–Ag
ration of 4.586 A. The remaining two positions around
four-coordinated Ag(I) in the chain are completed by
nitrogen atoms of two 4-abaH ligands. Thus, compound
2 might be regarded as an extension of compound 1
bond angle of 109.6(3)° is smaller than C–Naba–Ag bond
angle of 117.8(3)°. It is interesting that compound 3
contains both monodentate 4-abaH (Scheme 3b) and
exo-bidentate 4-aba (Scheme 3d). To the best of our
knowledge, this is the first example of co-existence of
4-aba and 4-abaH in reported metal complexes from
4-abaH. 4-aba in a l-N,O bridging mode and 4-abaH in
a monodentate mode link three-coordinated Ag(I) cen-
ters into a one-dimensional swallow-like chain. It is
noteworthy that 4-abaH and uncoordinated oxygen
atom of 4-aba from one adjacent chain form O–Hꢀ ꢀ ꢀO
ꢁ
through NO3 bridging two adjacent Ag(I) centers
(Fig. 2b). Similar to compound 1, each pair of carbox-
ylic acid from adjacent chains forms head-to-head O–
Hꢀ ꢀ ꢀH hydrogen bonds [R2ð8Þ in graph set notation]
2 ꢀ
[O(1)ꢀ ꢀ ꢀH–O(2)i ¼ 2.646(5) A; symmetry code: (i)
i
ꢀ
hydrogen bonds [O(22)–Hꢀ ꢀ ꢀO(11) 2.540(6) A; symme-
try code: (i) x ꢁ 1=2; ꢁy þ 1=2; z ꢁ 1=2], NH2 of 4-aba
and coordinated oxygen atom of 4-aba from the other
adjacent chain form cross-linked N–Hꢀ ꢀ ꢀO hydrogen
ii
ꢀ
bonds [O(12)ꢀ ꢀ ꢀH–N(1) 2.929(6) A; symmetry code: (ii)
x ꢁ 1=2; ꢁy ꢁ 1=2; z ꢁ 1=2]. These hydrogen-bonding
interactions consolidate the swallow-like chain and ex-
tend it into a two-dimensional layer structure. The
closest Agꢀ ꢀ ꢀAg separation in the adjacent chains is 3.38
ꢀ
A, which is below the summed van der Waals radius of
(a)
ꢀ
two silver atoms (3.44 A), indicating the presence of the
weak ligand-unsupported dimeric Agꢀ ꢀ ꢀAg interaction,
in which only limited number of structures has been
reported in the literatures [13a,17]. It is comparable with
those found in silver(I)-carboxylate complexes contain-
ing ligand-unsupported Agꢀ ꢀ ꢀAg interactions, such as
acetone solvate [Ag2(4-aba)2]n [2.9870(5) andþ3.0252(4)
ꢀ
A][13a] and betaine derivative [{Ag2(Me3N CH2CH2
COꢁ2 )2(H2O)}n][ClO4]2n ꢀ nH2O [3.269(2) and 3.346(2) A]
ꢀ
[17]. It should be pointed out that 4-abaH in 3 has not
formed head-to-head carboxylic acid hydrogen bonds,
which is probably ascribed to a hydrogen-bonding in-
teraction between H2O and 4-abaH [OW–Hꢀ ꢀ ꢀO(21)
(b)
ꢀ
2.843(6) A]. Thus, the uncoordinated aqueous molecules
Fig. 2. (a) View of one-dimensional chain in 2 with thermal ellipsoids
at 30% probability. (b) View of hydrogen bonds between adjacent
chains to form a two-dimensional layer in 2.
might have an important effect on formation of the
compound.

110
R. Wang et al. / Inorganica Chimica Acta 357 (2004) 103–114
(a)
(b)
Fig. 3. (a) View of one-dimensional chain in 3 with atomic numbering scheme. (b) View of two-dimensional hydrogen bonding layer in 3.
{[Ag(4,40-bipy)(H2O)](4-aba)0:5(NO3)0:5 ꢀ (H2O)0:5
}
layer through a pyridyl ring of 4,40-bipy with separation
n
ꢀ
(4). Compound 4 consists of the slightly distorted linear
ꢁ
of pyridyl rings being 3.50 A. The distance of Agꢀ ꢀ ꢀAg
[Ag(4,40-bipy)]n chains, NO3 and 4-aba counter anions
ꢀ
in adjacent parallel chains is 3.449 A. Similar layer skel-
as well as aqueous molecules. As shown in Fig. 4(a),
each Ag(I) center is coordinated by two nitrogen atoms
from different 4,40-bipy ligands in a slightly distorted
linear fashion to form a linear chain of alternating Ag(I)
etons have been exemplified by [Ag(4,40-bipy)]n (NO3ꢁ)n
[18a] and [Ag(4,40-bipy)H2PO4 ꢀ H3PO4]n [18b]. NO3
,
4-aba, and H2O between adjacent layers extend the two-
dimensional layer into a three-dimensional architecture
through hydrogen-bonding interactions involving in
coordinated aqueous molecules and 4-aba. As shown in
Fig. 4(b), one oxygen atom of 4-aba with two adjacent
H2O form Oꢀ ꢀ ꢀH–Ow hydrogen bonds [O(11)ꢀ ꢀ ꢀH–
and 4,40-bipy [Ag–N(1) ¼ 2.146(3) A, Ag–N(2A) ¼
ꢀ
ꢀ
2.151(2) A; N(1)–Ag–N(2A) 173.45(10)°]. Ag–N bond
distances are 2.146(3) and 2.151(2) A, which are typical
ꢀ
values for Ag(I)–Npy coordination distances [6a,19].
N(1)–Ag–N(2A) bond angle of 175.45(10)° is indicative
of the presence of a linear distortion in 4, which may be
ascribed to a weak interaction between Ag(I) and an
i
ꢀ
O(2W) 2.782(5); O(11)ꢀ ꢀ ꢀH–O(2W) 2.782(5) A; sym-
metry code: (i) x; ꢁy þ 3=2; z], the other oxygen atom of
4-aba with NH2 of another 4-aba form Oꢀ ꢀ ꢀH–N hy-
ii
ꢀ
ꢀ
adjacent aqueous molecule [Ag–O(2W) 2.695(3) A].
drogen bonds [O(12)ꢀ ꢀ ꢀH–N(11) 2.940(6) A; symmetry
code: (ii) x ꢁ 1; y; z]. Thus, 4-aba might be regarded as
the linkers of adjacent [Ag(4,40-bipy)]n layers and con-
solidate the structural framework through hydrogen
bonding interactions.
Thus, the coordination environment around Ag(I) can
also be described as a slightly distorted T-shaped
coordination geometry [N(1)–Ag–O(2W) ¼ 92.71(9)°,
N(2A)–Ag–O(2W) ¼ 90.81(9)°]. The pyridyl rings of
each 4,40-bipy are approximately coplanar with a twisted
angle of 5.8° and the Agꢀ ꢀ ꢀAg separation based on 4,40-
Ag[(3-aba)2H] (5). The crystal structure of 5 is
greatly different from that of compounds 1–3. The
carboxylic proton is generated from successive differ-
ence Fourier syntheses in solving the structure. As
shown in Fig. 5, each Ag(I) is coordinated by nitrogen
atoms of two 3-abaH0:5 in a completely linear geometry
0
ꢀ
bipy is 11.384 A. Each pair of parallel [Ag(4,4 -bipy)]n
chains is nearly completely overlapping with the sepa-
ꢀ
ration of pyridyl rings being 3.53 A and is further
stacked in an off-set fashion into a two-dimensional

R. Wang et al. / Inorganica Chimica Acta 357 (2004) 103–114
111
3.53
3.50
(a)
(b)
ꢁ
Fig. 4. (a) View of molecular ladder formed by p–p stacking in 4 with aqueous molecules, 4-aba, and NO3 omitted for clarity. (b) View of hydrogen
bonding three-dimensional structure in 4.
3.71
3.71
Fig. 5. Two-dimensional network structure formed by hydrogen bonding and p–p stacking interactions in 5.

112
R. Wang et al. / Inorganica Chimica Acta 357 (2004) 103–114
ꢀ
[Ag–N 2.135(4) A]. 3-abaH0:5 attached to Ag(I) center
are parallel to each other. Each 3-abaH0:5 contains half
carboxylic proton, two adjacent 3-abaH0:5 share one
carboxylic proton to form a O–H–O hydrogen bond
nificant p–p stacking interactions between phenyl rings
from adjacent chains. The phenyl rings are approxi-
mately parallel to each other with the dihedral angle
between them being 0.3° and the distance between
[O(2)ꢀ ꢀ ꢀHꢀ ꢀ ꢀO(2)i 2.481(7) A; symmetry code: (i)
their centroid being 3.71 A [19]. The p–p stacking
ꢀ
ꢀ
ꢁx ꢁ 1; ꢁy ꢁ 1; ꢁz þ 2]. The hydrogen bond interaction
extends Ag[(3-aba)2H] into a one-dimensional stair-like
chain. The stair-like chain is further extended into a
two-dimensional network structure through hydrogen
bonding interactions between the other oxygen atom 3-
abaH0:5 and NH2 of 3-abaH0:5 from the adjacent chain
interactions consolidate two-dimensional network
architecture.
{[Ag(3-aba)] ꢀ H2O}n (6). Single crystal X-ray dif-
fraction analysis reveals that compound 6 is a two-di-
mensional layer formed through 3-aba in a l3-N,O,O0
bridging mode linking three-coordinated Ag(I) centers.
As shown in Fig. 6, Ag(I) adopts a distorted trigonal
geometry and is coordinated by two oxygen atoms from
[O(1)ꢀ ꢀ ꢀH–Nii 2.958(5) A; symmetry code: (ii)
ꢀ
ꢁx; ꢁy ꢁ 1; ꢁz þ 1]. It is interesting that there are sig-
(a)
(b)
Fig. 6. (a) View of two-dimensional layer along a-axis in 6 with the lattice aqueous molecules omitted for clarity. (b) View of two-dimensional layer
along c-axis in 6.

R. Wang et al. / Inorganica Chimica Acta 357 (2004) 103–114
113
R
plexes through adjusting and controlling the pH value of
reaction system, where NH3 is a suitable base for con-
trolling carboxylic proton and plays an important role
in the self-assembly process of these ligands with sil-
ver(I). Moreover, coordination covalent bonds, hydro-
gen bonds, p–p stacking interaction, and their
combination are important tools for construction of
supramolecular architectures.
R
R
R
O
O
O
O
O
O
O
Ag
Ag
Ag
O
Ag
Ag
Ag
Ag
O
O
O
O
R
R
(III)
(I)
(II)
Scheme 4. The silver-carboxylate bridging modes.
5. Supplementary material
Crystallographic data (excluding structure factors) for
this paper have been deposited in the Cambridge Crys-
tallographic Data Centre as supplementary publication
No. 208906–208911. Copies of these information may be
obtained free of charge from the Director, CCDC, 12
Union Road, Cambridge, CB2 1EZ, UK (fax: +44-1223-
336-033; e-mail: deposit@ccdc.cam.ac.uk or www: http://
ccdc.cam.ac.uk).
different 3-aba ligands and one nitrogen atom from the
third 3-aba ligand (neglecting Ag–Ag interaction) [O(1)–
Ag–N(0B) 158.9(3)°, O(1)–Ag–O(2D) 100.2(2)°, and
N(0B)–Ag–O(2D) 99.9(2)°]. Ag(I) is approximately co-
planar with three coordination atoms with the deviation
ꢀ
of 0.1065 A from the plane defined by O(1), O(2D), and
N(0B). Each pair of adjacent Ag(I) centers is bridged by
l2-carboxylato-O,O0 group to generate an infinite Ag(I)
chain with the Ag–Ag–Ag bond angle of 170.01(5)°. The
ꢀ
Ag–Ag distance of 2.9484(3) A falls in the range of
ꢀ
2.78–3.00 A found for the series of known carboxyl-
Acknowledgements
ate-bridged Ag(I) dimers or dimeric polymers [20,21].
Silver(I)-carboxylate complexes have been extensively
researched and most of them are based on a bis(car-
boxylate-O,O0)-bridged dimer [12b,20] (Scheme 4a,b),
however, carboxylate bridging alternatively two adja-
cent Ag(I) centers in different directions has seldom been
reported (Scheme 4c) [21]. Each 3-aba acts as a l3-
bridge and links three Ag(I) through a nitrogen atom
and two oxygen atoms of carboxylate, respectively, to
extend the silver(I) chains into a two-dimensional net-
work, which is greatly different from those from 4-aba
[13] and 4-aminosalicylate [12b]. The lattice aqueous
molecule and an adjacent 3-aba oxygen atom form an
intermolecular hydrogen bonding interaction [Ow–Hꢀ ꢀ ꢀ
This work was supported by the National Nature
Science Foundation of China, Nature Science Founda-
tion of Fujian Province, and the Key Project of Chinese
Academy of Science.
References
[1] (a) J.-M. Lehn, Supramolecular Chemistry: Concepts and
Perspectives, VCH, New York, 1995;
(b) J.W. Steed, J.L. Atwood, Supramolecular Chemistry, Willey
and Sons, New York, 2000.
[2] (a) M. Eddaoudi, J. Kim, N. Rosi, D. Vodak, J. Wachter, M.
OÕkeeffe, O.M. Yaghi, Science 295 (2002) 469;
(b) B.J. Holliday, C.A. Mirkin, Angew. Chem. Int. Ed. 40 (2001)
2022;
O2i 2.733(10) A; symmetry code: (i) x; ꢁy þ 1=2;
ꢀ
z þ 1=2].
(c) P.J. Hagrman, D. Hagrman, J. Zubieta, Angew. Chem. Int.
Ed. 38 (1999) 2638.
4. Conclusion
[3] (a) B. Moulton, M.J. Zaworotko, Chem. Rev. 101 (2001) 1629;
(b) D.L. Caulder, K.N. Raymond, Acc. Chem. Res. 32 (1999)
975;
By controlling carboxylic groups of 4-aminobenzoic
acid (4-abaH) and 3-aminobenzoic acid (3-abaH) using
NH3, we have successfully synthesized a series of hy-
drogen-bonded silver(I) compounds. These compounds
exhibit some new structural varieties in Ag-(4-abaH)
and Ag-(3-abaH) system. Meanwhile, compounds 1 and
2 may act as precursors of compound 3 and [Ag(4-aba)]n
[13b]. Compound 5 may also serve as the precursor of
compound 6. In summary, this work demonstrates that
multifunctional organic ligands containing nitrogen
atom and carboxylic group are preferred building blocks
(c) D. Braga, F. Grepioni, G.R. Desiraju, Chem. Rev. 98 (1998)
1375.
[4] (a) E. Breuning, U. Ziener, J.-M. Lehn, E. Wegelius, K. Rissanen,
Eur. J. Inorg. Chem. (2001) 1515;
(b) T.J. Prior, M.J. Rosseinsky, Chem. Commun. (2001) 495;
(c) W. Lu, M.C.W. Chan, K.K. Cheung, C.M. Che, Organomet-
allics 20 (2001) 2477.
[5] (a) M. Edgar, R. Mitchell, A.M.Z. Slawin, P. Lightfoot, P.A.
Wright, Chem. Eur. J. 7 (2001) 5168;
(b) L. Carlucci, G. Ciani, D.M. Proserpio, A. Sironi, J. Chem.
Soc., Dalton Trans. (1997) 1801;
€
(c) C.B. Aakeroy, A.M. Beatty, D.S. Leinen, K.R. Lorimer,
Chem. Commun. (2000) 935.
for preparing various switchable supramolecular
com-

114
R. Wang et al. / Inorganica Chimica Acta 357 (2004) 103–114
[12] (a) R.H. Wang, M.C. Hong, J.H. Luo, R. Cao, Q. Shi, J.B. Weng,
[6] (a) A.N. Khlobystov, A.J. Blake, N.R. Champness, D.A.
€
Lemenovskii, A.G. Majouga, N.V. Zyk, M. Schroder, Coord.
Chem. Rev. 222 (2001) 155;
Eur. J. Inorg. Chem. (2002) 2904;
(b) R.H. Wang, M.C. Hong, Y.J. Zhao, J.B. Weng, Inorg. Chem.
Commun. 5 (2002) 487.
(b) O.S. Jung, Y.J. Kim, Y.A. Lee, J.K. Park, H.K. Chae, J. Am.
Chem. Soc. 122 (2000) 9921;
[13] (a) O. Kristiansson, Inorg. Chem. 40 (2001) 5058;
(b) I.R. Amiraslanov, B.T. subaliev, G.N. Nadzhafov, A.A.
Musaev, E.M. Movsumov, K.S. Mamedov, Zh. Strukt. Khim. 21
(1980) 112;
(c) M. Maekawa, H. Konaka, Y. Suenaga, T. Kuroda-Sowa, M.
Munakata, J. Chem. Soc., Dalton Trans. (2000) 4160;
(d) R.H. Wang, M.C. Hong, W.P. Su, Y.C. Liang, R. Cao, Y.J.
Zhao, J.B. Weng, Inorg. Chim. Acta 323 (2001) 139.
(c) G. Yang, H.G. Zhu, B.H. Liang, X.M. Chen, J. Chem. Soc.,
Dalton Trans. (2001) 580;
[7] (a) M. Scherer, D.L. Caulder, D.W. Johnson, K.N. Raymond,
Angew. Chem. Int. Ed. 38 (1999) 1587;
(d) G. Smith, D.E. Lynch, K.A. Byriel, C.H.L. Kennard, Inorg.
Chem. 35 (1996) 2711.
(b) B.J.S. Johnson, R.C. Schroden, C. Zhu, A. Stein, Inorg.
Chem. 40 (2001) 5972;
[14] G. Smith, B.A. Cloutt, D.E. Lynch, K.A. Byriel, C.H.L. Kennard,
Inorg. Chem. 37 (1998) 3236.
(c) A.J. Blake, N.R. Champness, P.A. Cooke, J.E.B. Nicolson,
Chem. Commun. (2000) 665;
[15] G. Smith, K.A. Byriel, C.H.L. Kennard, Aust. J. Chem. 52 (1999)
325.
ꢁ
ꢁ
ꢁ
ꢂ ꢁ ꢁ ꢁ
(d) J. Makarevic, M. Jokic, B. Peric, V. Tomisic, B. Kojic-Prodic,
ꢂ
M. Zinic, Chem. Eur. J. 7 (2001) 3328.
ꢁ
[16] J. Bernstein, R.E. Davis, L. Shimoni, N.L. Chang, Angew. Chem.
Int. Ed. Engl. 34 (1995) 1555.
[8] (a) L. Pan, E.B. Woodlock, X. Wang, K.C. Lam, A.L. Rheingold,
Chem. Commun. (2001) 1762;
[17] X.M. Chen, T.C.W. Mak, J. Chem. Soc., Dalton Trans. (1991)
3253.
(b) K.S. Min, M.P. Suh, J. Am. Chem. Soc. 122 (2000) 6834;
(c) O.S. Jung, S.H. Park, K.M. Kim, H.G. Jang, Inorg. Chem. 37
(1998) 5781.
[18] (a) F. Robinson, M.J. Zaworotko, J. Chem. Soc., Chem.
Commun. (1995) 2413;
[9] B. Hasenknopf, J.-M. Lehn, N. Boumediene, E. Leize, A.V.
Dorsselaer, Angew. Chem. Int. Ed. 37 (1998) 3265.
[10] (a) C.T. Yang, B. Moubaraki, K.S. Murray, J.D. Ranford, J.J.
Vittal, Inorg. Chem. 40 (2001) 5934;
(b) M.L. Tong, X.M. Chen, S.W. Ng, Inorg. Chem. Commun. 3
(2000) 436.
[19] (a) M. Munakata, L.P. Wu, T. Kuroda-Sowa, Adv. Inorg. Chem.
46 (1999) 173;
(b) N. Matsumoto, Y. Motoda, T. Matsuo, T. Nakashima, N. Re,
F. Dahan, J.P. Tuchagues, Inorg. Chem. 38 (1999) 1165.
[11] (a) W.P Su, M.C. Hong, J.B. Weng, R. Cao, S.F. Lu, Angew.
Chem. Int. Ed. 39 (2000) 2911;
(b) C. Janiak, J. Chem. Soc., Dalton Trans. (2000) 3885.
[20] (a) V.W.W. Yam, K.K.W. Lo, W.K.M. Fung, C.R. Wang,
Coord. Chem. Rev. 171 (1998) 17;
€
€
(b) D. Ulku, M.N. Tahir, E.M. Muvsumov, Acta Cryst. C 52
(1996) 2678;
(b) M.C. Hong, W.P. Su, R. Cao, W.J. Zhang, W.-T. Wong, J.X.
Lu, Inorg. Chem. 38 (1999) 600;
(c) G. Smith, A.N. Reddy, Polyhedron 13 (1994) 2425;
(d) T.C.W. Mak, W.-H. Yip, C.H.L. Kennard, G. Smith, E.J.
OÕReilly, Aust. J. Chem. 39 (1986) 541, and references therein.
[21] T.C.W. Mak, W.H. Yip, C.H.L. Kennard, G. Smith, E.J.
OÕReilly, J. Chem. Soc., Dalton Trans. (1988) 2353.
(c) W.P. Su, M.C. Hong, J.B. Weng, Y.C. Liang, Y.J. Zhao, R.
Cao, Z.Y. Zhou, A.S.C. Chan, Inorg. Chim. Acta 331 (2002) 8;
(d) W.P. Su, R. Cao, M.C. Hong, W.J. Zhang, W.-T. Wong, J.X.
Lu, Inorg. Chem. Commun. 2 (1999) 241.