A new two-dimensional AgI coordination polymer with Ag?C interactions: Thermal, fluorescence, structural and solution studies

Article abstract of DOI:10.1016/j.jorganchem.2007.10.057

A 2D polymer with Ag?C interactions, [Ag(μ₅-TS)]_n (1) [TS^- = toluene-4-sulfonate], has been synthesized and characterized and its structure was determined by X-ray crystallography. In addition to coordination of the O atoms of TS^-, the Ag atoms also form weak η¹ Ag?C interactions. The thermal stability of 1 was studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The ligand and compound 1 are luminescent in DMF, with emission maxima at 358 and 335, respectively. Solution studies of complex 1 were done in DMF and in CH₃CN.

Full text of DOI:10.1016/j.jorganchem.2007.10.057

Available online at www.sciencedirect.com
Journal of Organometallic Chemistry 693 (2008) 257–262
www.elsevier.com/locate/jorganchem
A new two-dimensional AgI coordination polymer with
AgÁ Á ÁC interactions: Thermal, fluorescence, structural
and solution studies
a
a,
b
c
Kamran Akhbari , Ali Morsali *, Shahnaz Rafiei , Matthias Zeller
a
Department of Chemistry, School of Sciences, Tarbiat Modares University, P.O. Box 14155-4838, Tehran, Islamic Republic of Iran
b
Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
Department of Chemistry, Youngstown State University, One University Plaza, P.O. Box 44555-3663, Youngstown, OH, USA
c
Received 2 September 2007; received in revised form 29 October 2007; accepted 31 October 2007
Available online 7 November 2007
Abstract
A 2D polymer with AgÁ Á ÁC interactions, [Ag(l5-TS)]n (1) [TSÀ = toluene-4-sulfonate], has been synthesized and characterized and its
structure was determined by X-ray crystallography. In addition to coordination of the O atoms of TSÀ, the Ag atoms also form weak g1
AgÁ Á ÁC interactions. The thermal stability of 1 was studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The
ligand and compound 1 are luminescent in DMF, with emission maxima at 358 and 335, respectively. Solution studies of complex 1 were
done in DMF and in CH3CN.
ꢀ 2007 Elsevier B.V. All rights reserved.
Keywords: Silver(I); Toluene-4-sulfonic acid; AgÁ Á ÁC interaction; Coordination polymer; Fluorescence; Thermal; Solution study
1. Introduction
have addressed that metal–heteroatom [7], metal–carbon
[8] and metal–metal [9] interactions are three of the most
The self-assembly approach to the construction of
important interactions in the construction of Ag polymeric
supramolecules or extended frameworks based on coordi-
networks in the solid state. However, although the closed
nation complexes is one of the major current research areas
d10 configuration of silver(I) appears to cancel any interme-
in inorganic and organometallic chemistry [1]. In the vast
tallic bonding in silver(I) complexes, there are many exam-
majority of such compounds, the molecular building blocks
ples of dimeric or polymeric silver(I) complexes with
are held together by strong metal–ligand–metal bonding
definite Ag/Ag attractive forces known as argentophilic
interactions or weaker forces such as hydrogen bonding
interactions [9]. In this paper we describe the synthesis
between ligands coordinating to the different metal units.
and coordination behaviour of TSÀ ligand based on
The use of bridging ligands for the controlled self-assembly
O,C-donor atoms. In addition thermal, emission and solu-
of one-, two- or three-dimensional metallosupramolecular
tion studies of compound 1 were also studied.
species has been the subject of enormous study in recent
years [2]. In coordination polymers, the silver(I) ions give
O
S
rise to an interesting array of stereochemistries and
geometric configurations with the coordination numbers
of two to six all occurring [3–6]. Previous investigations
H3C
OH
*
Corresponding author. Tel.: +98 2188011001; fax: +98 2188011101.
E-mail address: morsali_a@yahoo.com (A. Morsali).
O
HTS
0022-328X/$ - see front matter ꢀ 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2007.10.057

258
K. Akhbari et al. / Journal of Organometallic Chemistry 693 (2008) 257–262
Table 1
2. Experimental
Crystal data and structure refinement for compound [Ag(l5-TS)]n (1)
Identification code
Empirical formula
Formula weight
Temperature (K)
Wavelength (A)
Crystal system
Space group
1
2.1. Materials and physical techniques
C7H7AgO3S
279.06
100(2)
0.71073
Monoclinic
P21/c
All chemicals were of reagent grade and were used as
commercially obtained without further purification. IR
spectra were recorded using Perkin–Elmer 597 and Nicolet
510P spectrophotometers. Microanalyses were carried out
using a Heraeus CHN–O– Rapid analyzer. Melting points
were measured on an Electrothermal 9100 apparatus and
are uncorrected. The thermal behavior was measured with
a PL-STA 1500 apparatus. The luminescent properties were
investigated with a Shimadzu RF-5000 spectrofluoropho-
tometer. All UV–Visible spectra were recorded on a
computerized double-beam Shimadzu 2550 spectropho-
tometer, using two matched 10-mm quartz cells. Conducto-
metric measurements were carried out with a Metrohm 712
conductometer equipped with a Julabo F12-MB circulator.
Crystallographic measurements were made at 100(2) K
using a Bruker SMART APEX CCD area detector. The
intensity data were collected using graphite monochromat-
˚
Unit cell dimensions
˚
a (A)
15.444(6)
6.050(2)
8.587(3)
90.00
94.035(7)
90.00
800.4(5)
4
2.316 g cmÀ3
2.736 mmÀ1
544
0.46 · 0.32 · 0.08 mm3
2.64–28.28
À20 6 h 6 20, À8 6 k 6 8,
À11 6 l 6 11
7027
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
3
˚
Volume (A )
Z
Density (calculated)
Absorption coefficient
F(000)
Crystal size
Theta range for data collection (ꢁ)
Index ranges
˚
ed Mo Ka radiation (k = 0.71073 A). Accurate unit cell
Reflections collected
Independent reflections
Absorption correction
Maximum and minimum
transmission
1969 (R(int) = 0.0567)
Multi-scan
0.803 and 0.328
parameters and the orientation matrix were obtained from
least-squares refinement. The structure has been solved by
direct methods and refined by full-matrix least-squares tech-
niques on F2 using SHELXTL [10]. The molecular structure
plots were prepared using ORTEP and MERCURY [11]. Crystal-
lographic data and details of the data collection and struc-
ture refinements are listed in Table 1. The observed
anisotropic thermal parameters, the calculated structure
factors, and full lists of bond distances, bond angles and
torsion angles are given in the supplementary material.
Refinement method
Full-matrix least-squares on F2
1969/0/110
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2r(I)]
R Indices (all data)
1.047
R1 = 0.0784, wR2 = 0.2112
R1 = 0.0897, wR2 = 0.2237
8.358 and À3.198
Largest difference in peak and hole
À3
˚
(e A
)
2.2. Synthesis of [Ag(l5-TS)]n (1)
by X–ray crystallography showed the complex to be a two-
dimensional polymer (Figs. 1–3). The silver atoms can be
considered to be five-coordinate (Fig. 2). The sulfonate
group of the TSÀ ligand acts as a bridging group where
each oxygen atoms of the sulfonate group coordinates to
a silver(I) ion, and two of these oxygen atoms also bridge
to another two silver atoms (Scheme 1). The structure of
compound 1 may also be considered as a coordination
polymer consisting of two-dimensional sheets constructed
from Ag(I) ions and bridging sulfonate groups, running
parallel to the bc sheet and the individual polymeric layers
are almost parallel to each other along the a axis, resulting
in two-dimensional sheets as shown in Fig. 3.
In 10 ml methanol 0.172 g (1 mmol) toluene-4-sulfonic
acid (HTS) were mixed and stirred with a solution of
0.057 g (1 mmol) KOH in 3 ml H2O to form a clear solution.
Addition of 0.170 g (1 mmol) Ag(NO3) in 5 ml H2O pro-
duced a clear solution that was stirred and then allowed to
stand in darkness at room temperature to evaporate for sev-
eral days to obtain crystals suitable for single crystal X-ray
diffraction. The crystals were washed with acetone and air
dried, m.p. = 250 ꢁC, Yield: 0.131 g (47%). IR (selected
bands; in cmÀ1): 535m, 559s, 687s, 806s, 843w, 947w,
1002s, 1034s, 1125vs, 1189vs, 1397w, 1437w, and 1485w.
Anal. Calc. for C7H7AgO3S: C, 30.10; H, 2.51; Ag, 38.
34%. Found: C, 29.95; H, 2.45; Ag, 38. 90%.
The structure was analyzed for close AgÁ Á ÁAg and
AgÁ Á ÁC contacts. The closest Ag–Ag interaction in com-
˚
pound 1, Ag1–Ag1 = 3.368 A (Table 2), is longer than
the Ag–Ag distances in similar dinuclear complexes (i.e.,
2.704(2), 2.669(1), and 2.726(1) A) [9b,12–15] and also
3. Results and discussion
˚
longer than the twice the van der Waals radius of Ag
(3.44 A), [16], indicating that there are no argentophilic
interactions in compound 1. On the other hand it appears
that the silver ions may be involved in AgÁ Á ÁC (g1) interac-
tions between the silver atoms and phenyl groups of TSÀ
3.1. Structure description
˚
The reaction between toluene-4-sulfonate (TSÀ) and
Ag(NO3) provided a crystalline material of the general for-
mula [Ag(l5-TS)]n (1). Determination of the structure of 1

K. Akhbari et al. / Journal of Organometallic Chemistry 693 (2008) 257–262
259
Fig. 1. ORTEP diagram of compound [Ag(l5-TS)]n (1).
Fig. 2. Environment of the Ag-atoms in compound 1 after extending the
bonding limit to show the AgÁ Á ÁC interactions.
Fig. 3. A fragment of the two-dimensional polymer in compound 1. H
atoms are omitted for clarity.
Ag
˚
(Fig. 2), with a Ag(1)–C(2) distance of 3.229 A, thus
augmenting the AgI Ag1O5 coordination sphere, and
compound 1 can be considered to contain silver atoms
with an O5AgÁ Á ÁC environment. In compounds with
similar interactions the Ag–C distances are in the range
O
Ag
H3C
S
O
Ag
O
˚
of 2.40–2.70 A [17–20], in [Ag(benzene)ClO4] for exam-
˚
Ag
Ag
ple they are 2.496 and 2.634 A [14]. Some other Ag(I)
polymeric complexes with Ag–C(sp2) bonded polycyclic
Scheme 1. The coordination mode of ligand TSÀ in compound 1.
aromatic ligands have been reported to have mean
Ag–arene distances of 2.82–3.37 A [6,21–24]. Thus, the
˚
4. Thermogravimetric analysis
interaction in compound 1 can be considered as a
weak monohapto aromatic coordination to the Ag
atoms.
To examine the thermal stability of compound 1,
thermal gravimetric (TG) and differential thermal analy-

260
K. Akhbari et al. / Journal of Organometallic Chemistry 693 (2008) 257–262
Table 2
˚
Selected bond lengths (A) and angles (ꢁ) for compound [Ag(l5-TS)]n (1)
Ag(1)–O(2)#1
Ag(1)–O(1)#2
Ag(1)–O(3)
Ag(1)–O(3)#3
Ag(1)–Ag(1)#4
Ag(1)–Ag(1)#1
2.392(5)
2.433(5)
2.452(5)
2.537(5)
3.3682(12)
3.3682(12)
O(2)#1–Ag(1)–O(1)#2
O(2)#1–Ag(1)–O(3)
O(1)#2–Ag(1)–O(3)
O(2)#1–Ag(1)–O(3)#3
O(1)#2–Ag(1)–O(3)#3
O(3)–Ag(1)–O(3)#3
96.54(18)
165.87(18)
90.43(18)
93.86(18)
132.54(18)
72.5(2)
O(1)#2–Ag(1)–Ag(1)#4
O(3)#3–Ag(1)–Ag(1)#4
O(1)#2–Ag(1)–Ag(1)#1
O(3)#3–Ag(1)–Ag(1)#1
O(2)#1–Ag(1)–Ag(1)#4
52.77(13)
152.33(12)
168.89(12)
53.41(13)
113.24(13)
O(3)–Ag(1)–Ag(1)#4
O(2)#1–Ag(1)–Ag(1)#1
O(3)–Ag(1)–Ag(1)#1
Ag(1)#4–Ag(1)–Ag(1)#1
80.74(13)
72.85(13)
100.65(13)
127.83(4)
#1: Àx + 2, y À 1/2, Àz À 1/2; #2: Àx + 2, Ày + 1 À z; #3 Àx + 2, Ày, Àz; #4: Àx + 2, y + 1/2, Àz À 1/2.
ses (DTA) were carried out between 30 and 700 ꢁC in a
static atmosphere of air (Fig. S1). Compound 1 melts at
250 ꢁC with an endothermic peak at this temperature.
The TG curve exhibits two decomposition stages
between 325 and 475 ꢁC with a mass loss of 61.9%
(calcd 61.3%). The DTA curve displays three endother-
mic peaks with a maximum intensity at 250, 338 and
359 ꢁC associated with a first decomposition state and
a very sharp exothermic peak at 465 ꢁC associated with
a second decomposition state. Mass loss calculations of
the end residue show that the final decomposition prod-
uct is Ag2O.
matic groups of the ligand [25]. In DMF emission bands
have been observed both for compound 1 and also the
ligand HTS at 335 and 358 nm upon excitation at
300 nm, respectively (Fig. 4). Compared with the emis-
sion of the free ligand HTS, a blue shift of ca. 23 nm
has been observed upon the coordination of the TSÀ
ligand to Ag(I) atoms in 1 [8m]. It should be noted that
luminescent silver(I) compounds, usually exhibiting emis-
sion at low temperature, are unstable organometallic
compounds containing chalcogenides and acetylides as
bridging ligands [26]. Only a few monomeric [27] and
polymeric [28] silver(I) complexes that exhibited lumines-
cent properties at room temperature have been reported.
However, our current complex is strongly luminescent at
ambient temperature.
5. Luminescent properties
The UV/Vis and emission spectra of compound 1 as
well as the pure ligand HTS were studied. The UV/Vis
spectra of both ligand and complex in DMF display
intense absorption bands with the maximum intensity
at 272 nm (Fig. 4), indicating that electronic transitions
are mostly of p to p* character, originating from the aro-
6. Solution studies
In the spectrophotometric analysis, 2.0 ml of the ligand
solution (2.0 · 10À4 M) in DMF was deprotonated with
KOH. The solution was placed in the spectrophotometer
cell and the absorbance of solution was measured. Then
a known amount of the concentrated solution of silver(I)
nitrate in DMF (5.2 · 10À3 M) was added in a stepwise
manner using a 5-ll Hamilton syringe. The absorbance
spectrum of the solution was recorded after each addition.
The electronic absorption spectra of the ligand toluene-4-
sulfonate (TSÀ) in the presence of increasing concentra-
tions of silver(I) ions at room temperature are shown in
Fig. S2. The strong absorption of the ligand at 272 nm
increases with increasing concentration of the metal ion.
The absorbance, measured against the [Ag+]/[TSÀ] mole
ratio as shown in the inset of Fig. S2, revealed no inflec-
tion point at a metal-to-ligand molar ratio of about 1.
Similar spectrophotometric studies were also done in
CH3CN solution, but also no inflection point was
observed at a metal-to-ligand molar ratio of about 1
(Fig. S3). The formation and stoichiometry of the Ag+–
TSÀ complex in DMF and CH3CN solution was also
investigated by a conductometric analysis. 20.0 ml of a sil-
ver(I) nitrate solution (5.0 · 10À5 M) in DMF was placed
in a two-wall thermostated glass cell, the temperature was
adjusted to 25.00 0.05 ꢁC, and the conductance of the
Fig. 4. Electronic absorption of ligand HTS (a), electronic absorption of
compound 1 (b). Absorption: c = 5.0 · 10À2 mol lÀ1, DMF, d = 1 cm for
both ligand HTS and compound 1. Solution-state emission spectrum for
compound 1 (c). Solution-state emission spectrum for ligand HTS (d).
Room temperature, kexc = 300 nm.

K. Akhbari et al. / Journal of Organometallic Chemistry 693 (2008) 257–262
261
solution was measured. Then a known amount of the con-
Appendix A. Supplementary material
centrated solution of ligand (TSÀ) in DMF (5.0 · 10À3 M)
was added in a stepwise manner using a 5-ll Hamilton
syringe. The conductance of the solution was measured
after each addition. The ligand solution was continually
added. The conductivity of a 5.0 · 10À5 M solution of sil-
ver(I) nitrate in DMF was monitored as a function of
[TSÀ]/[Ag+] mole ratio at 25.00 0.05 ꢁC and the result-
ing plot is shown in Fig. S4. Addition of the ligand to
the metal salt solution causes a linear increase in the solu-
tion conductivity with no inflection point at a molar ratio
of about one. Similar conductometric studies were also
done in CH3CN solution, but also no inflection point
was observed at a metal-to-ligand molar ratio of about
1 (Fig. S4).
CCDC 659320 contains the supplementary crystallo-
graphic data for 1. These data can be obtained free of
charge from The Cambridge Crystallographic Data Centre
via www.ccdc.cam.ac.uk/data_request/cif. Supplementary
data associated with this article can be found, in the online
version, at doi:10.1016/j.jorganchem.2007.10.057.
References
[1] (a) P.J. Stang, B. Olenyuk, Acc. Chem. Res. 30 (1997) 502;
(b) D. Braga, F. Grepioni, G.R. Desiraju, Chem. Rev. 98 (1998)
1375;
(c) O.M. Yaghi, H. Li, C. Davis, D. Richardson, T.L. Groy, Acc.
Chem. Res. 31 (1998) 474;
With the absence of a visible inflection point, we
could not evaluate the conditional formation constants
from the spectrophotometric and conductometric meth-
ods as would be otherwise possible [29]. Emission studies
of compound 1 in DMF solution show that we could
consider interactions between TSÀ and Ag+ in solution
state, thus we would have to conclude from the basically
linear increase of the absorbance and conductance in
Figs. S2–S4 that the ligand TSÀ shows similar interac-
tions with each of the varying amounts of metal ion
concentrations up to a molar ratio of about 3 and 4 in
both spectrophotometric and conductometric methods,
respectively. These results of the stoichiometry and for-
mation studies of complex of 1 in DMF and CH3CN
solution, however, are not supported by the solid state
stoichiometry.
(d) P.F.H. Schwab, M.D. Levin, J. Michl, Chem. Rev. 99 (1999)
1863;
(e) S. Leininger, B. Olenyuk, P.J. Stang, Chem. Rev. 100 (2000)
853.
[2] (a) S. Leininger, B. Olenyuk, P.J. Stang, Chem. Rev. 100 (2000) 853;
(b) G.F. Swiegers, T.J. Malefetse, Chem. Rev. 100 (2000) 3483;
(c) B. Moulton, M.J. Zaworotko, Chem. Rev. 101 (2001) 1629;
(d) M. Fujita, K. Umemoto, M. Yoshizawa, N. Fujita, T. Kusukawa,
K. Bi-radha, Chem. Commun. (2001) 509;
(e) D.W. Johnson, K.N. Raymond, Supramol. Chem. 13 (2001) 639;
(f) B.J. Holliday, C.A. Mirkin, Angew. Chem. Int. Ed. 40 (2001)
2022;
(g) G.F. Swiegers, T.J. Malefetse, Coord. Chem. Rev. 225 (2002) 91.
[3] M.-C. Brandys, R.J. Puddephatt, J. Am. Chem. Soc. 124 (2002) 3946.
[4] V.W.W. Yam, K.K.W. Lo, W.K.M. Fung, C.R. Wang, Coord.
Chem. Rev. 171 (1998) 17.
[5] S.-L. Zheng, M.-L. Tong, X.-M. Chen, Coord. Chem. Rev. 246
(2003) 185.
[6] A.N. Khlobystov, A.J. Blake, N.R. Champness, D.A. Lemenovskii,
A.G. Majouga, N.V. Zyk, M. Schro¨der, Coord. Chem. Rev. 222
(2001) 155, and references therein.
7. Conclusions
[7] (a) X. Huang, J. Zhang, X. Chen, Cryst. Growth Des. 6 (2006) 1194;
(b) J. Yang, S. Zheng, X. Yu, X. Chen, Cryst. Growth Des. 4 (2004)
831;
A new AgI two-dimensional coordination polymer of
toluene-4-sulfonic acid (HTS) ligand, [Ag(l5-TS)]n, was
synthesized and characterized. One of the Caromatic
TSÀ ligand in compound 1 exhibits a weak interaction
with Ag+ ion, in addition to the normal sulfonate coor-
dination modes. The individual two-dimensional sheets
in the compound [Ag(l5-TS)]n are almost parallel to
each other along the a axis. The results of studies of
the stoichiometry and formation of [Tl(l4-AB)]n in
DMF solution were not found to be in support of their
solid state stoichiometry. Compound 1 is one of only
very few stable monomeric and polymeric silver(I) com-
plexes that exhibit luminescent properties at room
temperature.
(c) S. Zheng, M. Tong, R. Fu, X. Chen, S. Ng, Inorg. Chem. 40
(2001) 3562;
(d) J. Zhang, Y. Lin, X. Huang, X. Chen, Inorg. Chem. 44 (2005)
3146;
(e) X. Huang, S. Zheng, J. Zhang, X. Chen, Eur. J. Inorg. Chem.
(2004) 1024.
[8] (a) P.F. Rodesiler, E.L. Amma, Inorg. Chem. 11 (1972) 388;
(b) E.A.H. Griffith, E.L. Amma, J. Am. Chem. Soc. 96 (1974) 743;
(c) E.A.H. Griffith, E.L. Amma, J. Am. Chem. Soc. 96 (1974) 5407;
(d) R.W. Turner, E.L. Amma, J. Am. Chem. Soc. 88 (1966) 3243;
(e) J.C. Barnes, C.S. Blyth, Inorg. Chim. Acta 98 (1985) 181;
(f) R.E. Rundle, J.H. Goring, J. Am. Chem. Soc. 72 (1950) 5337;
(g) H. Schmidbaur, W. Bublak, B. Huber, G. Reber, G. Muller,
Angew. Chem., Int. Ed. Engl. 25 (1986) 1089;
(h) G.L. Ning, L.P. Wu, K. Sugimoto, M. Munakata, T. Kuroda-
Sowa, M. Mackawa, J. Chem. Soc., Dalton Trans. (1999) 2529;
(i) M. Munakata, L.P. Wu, T. Kuroda-Sowa, M. Maekawa, Y.
Suenaga, G.L. Ning, T. Kojima, J. Am. Chem. Soc. 120 (1998) 8610;
(j) S. Zheng, J. Zhang, W. Wong, X. Chen, J. Am. Chem. Soc. 125
(2003) 6882;
Acknowledgements
(k) S.V. Ivanov, S. Miller, O. Anderson, S. Strauss, Cryst. Growth
Des. 4 (2004) 249;
(l) O. Jung, Y. Kim, Y. Lee, S. Kang, S. Choi, Cryst. Growth Des. 4
(2004) 23;
(m) S. Zheng, M. Tong, S. Tan, Y. Wang, J. Shi, Y. Tong, H. Lee,
X. Chen, Organometallics 20 (2001) 5319.
Support of this investigation by Iran National Science
Foundation, INSF (Project Number 84118) is gratefully
acknowledged. The Smart Apex diffractometer was funded
by NSF Grant 0087210, by Ohio Board of Regents Grant
CAP-491, and by YSU.

262
K. Akhbari et al. / Journal of Organometallic Chemistry 693 (2008) 257–262
[9] (a) P. Pyykko¨, Chem. Rev. 97 (1997) 597;
[23] A.J. Blake, G. Baum, N.R. Champness, S.S.M. Chung, P.A. Cooke,
D. Fenske, A.N. Khlobystov, D.A. Lemenovskii, W.S. Li, M.
Schro¨der, J. Chem. Soc., Dalton Trans. (2000) 4285.
[24] R. Sneider, M.W. Hosseini, J.-M. Planeix, A.D. Cian, J. Fischer,
Chem. Commun. (1998) 1625.
[25] R.D. Schmitt, R.M. Wing, A.H. Maki, J. Am. Chem. Soc. 91 (1969)
4394.
[26] (a) V.W.W. Yam, K.K.-W. Lo, W.K.-M. Fung, C.-R. Wang, Coord.
Chem. Rev. 171 (1998) 17;
(b) P.D. Harvey, D. Fortin, Coord. Chem. Rev. 171 (1998) 351;
(c) M.A. Omary, H.H. Patterson, J. Am. Chem. Soc. 120 (1998) 7696.
[27] (a) C.-M. Chi, H.-K. Yip, D. Li, S.-M. Peng, G.-H. Lee, Y.-M.
Wang, S.-T. Liu, Chem. Commun. (1991) 1615;
(b) D. Fortin, M. Drouin, M. Turcotte, P.D. Harvey, J. Am. Chem.
Soc. 119 (1997) 531;
(b) M. Jansen, Angew. Chem. Int. Ed. 26 (1987) 1098;
(c) M. Tong, X. Chen, B. Ye, L. Ji, Angew. Chem. Int. Ed. 38 (1999)
2237.
[10] Bruker Advanced X-ray Solutions SHELXTL (Version 6.14), Bruker
AXS Inc., Madison, WI, USA, 2003.
[11] MERCURY 1.4.1, Copyright Cambridge Crystallographic Data Centre,
12 Union Road, Cambridge, CB2 1EZ, UK, 2001–2005.
[12] B. Coyle, M. McCann, K. Kavanagh, M. Devereux, V. Mckee, N.
Kayal, D. Egan, C. Deagan, G.J. Finn, J. Inorg. Biochem. 98 (2004)
1361.
[13] V.T. Yilmaz, S. Hamamci, W.T.A. Harrison, C. Tho¨ne, Polyhedron
24 (2005) 693.
[14] L.S. Ahmet, J.R. Dilworth, J.R. Miller, N. Wheatley, Inorg. Chim.
Acta 278 (1998) 229.
[15] S.-P. Yang, H.-L. Zhu, X.-H. Yin, X.-M. Chen, L.-N. Ji, Polyhedron
19 (2000) 2237.
[16] The van der Waals radius of Ag is 1.72 A, see A. Bondi, J. Phys.
(c) T. Ren, C. Lin, P. Amalberti, D. Macikenas, J.D. Protasiewicz,
J.C. Baum, T.L. Gibson, Inorg. Chem. Commun. 1 (1998) 23;
(d) A. Vogler, H. Hunkely, Chem. Phys. Lett. 158 (1989) 74;
(e) V.J. Catalano, H.M. Kar, J. Garnas, Angew. Chem., Int. Ed. 38
(1999) 1979.
˚
Chem. 68 (1964) 441.
[17] H.G. Smith, R.E. Rundle, J. Am. Chem. Soc. 80 (1958) 5075.
[18] E.A.H. Griffiths, E.L. Amma, J. Am. Chem. Soc. 96 (1974) 5407.
[19] T.C.H. Mak, W.C. Ho, N.Z. Huang, J. Organomet. Chem. 251
(1983) 413.
[20] H.O. Davies, J.R. Dilworth, D.V. Griffiths, J.R. Miller, Polyhedron
18 (1999) 459.
[21] (a) L.J. Andrews, R.M. Keefer, J. Am. Chem. Soc. 71 (1949) 3644;
(b) L.J. Andrews, R.M. Keefer, J. Am. Chem. Soc. 72 (1950) 5034.
[22] M. Mascal, J.L. Kerdelhue, A.J. Blake, P.A. Cooke, R.J. Mortimer,
S.J. Teat, Eur. J. Inorg. Chem. (2000) 485.
[28] (a) M.-L. Tong, X.-M. Chen, B.-H. Ye, L.-N. Ji, Angew. Chem., Int.
Ed. 38 (1999) 2237;
(b) M.-L. Tong, X.-L. Yu, X.-M. Chen, Inorg. Chem. Commun. 3
(2000) 696;
(c) B.-L. Fei, W.-Y. Sun, T. Okamura, W.-X. Tang, N. Ueyama,
New J. Chem. 25 (2001) 210.
[29] (a) K. Akhbari, A. Morsali, M. Zeller, J. Organomet. Chem. 692
(2007) 3788;
(b) K. Akhbari, A. Morsali, Inorg. Chem. Commun. 10 (2007) 1189.