Three-dimensional silver(i) co-ordination polymer with pocket structures

Article abstract of DOI:10.1039/b003944f

Silver(i) complexes of hexakis(phenylsulfanyl)benzene (hphb), [Ag₂(hphb)][PF₆]₂ 1 and [Ag(hphb)(NO₃)] 2, have been prepared and their molecular structures determined by X-ray crystallography. In 1 the silver ion

Full text of DOI:10.1039/b003944f

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Three-dimensional silver(I) co-ordination polymer with pocket
structures
Yusaku Suenaga,*a Takayoshi Kuroda-Sowa,a Masahiko Maekawab and Megumu Munakataa
a Department of Chemistry, Kinki University, Kowakae, Higashi-Osaka, Osaka 577-8502,
Japan
b Research Institute for Science and Technology, Kinki University, Kowakae, Higashi-Osaka,
Osaka 577-8502, Japan
Received 17th May 2000, Accepted 24th August 2000
First published as an Advance Article on the web 26th September 2000
Silver() complexes of hexakis(phenylsulfanyl)benzene (hphb), [Ag2(hphb)][PF6]2 1 and [Ag(hphb)(NO3)] 2, have been
prepared and their molecular structures determined by X-ray crystallography. In 1 the silver ion adopts a tetrahedral
co-ordination geometry comprising four S atoms from two different hphb molecules and giving an eight-membered
Ag–S ring structure in a co-ordination polymer. This ring (6.46 × 6.79 Å) forms a three-dimensional framework with
pockets. On the other hand, for 2, the silver() ion has a square pyramidal environment with four S atoms and one
O atom of a NO3Ϫ anion. The complex forms a linear-chain structure with an alternating arrangement of silver ions
and hphb.
The self-assembling process of metal complexes continues to
be of considerable interest in the context of developing new
solid-state polymeric materials with specific architectural and
functional features.1 Silver() ions are regarded as extremely soft
acids favouring co-ordination to soft bases, such as ligands con-
taining S and unsaturated N. Complexes with these soft ligands
give rise to an interesting array of stereochemistries and geo-
metric configurations, with co-ordination numbers of two to
Experimental
six all occurring. Therefore silver() is often used to construct
network structures.2 However co-ordination complexes of
Preparations were performed using the usual Schlenk tech-
thioether ligands with the d10 silver() ion have mainly been
niques. All solvents were dried and distilled by standard
methods before use. The standard chemicals were obtained
restricted to macrocyclic thioethers.3 We are exploring ways to
modify the substituents to tailor the silver()/SR ligand polymer
structures as to the mode of polymerization, dimensionality
and the framework. In its complex with hexakis(methylsulf-
anyl)benzene (hmb), silver() has a tetrahedral co-ordination
by four S atoms and two S atoms in para position are not
co-ordinated. The nearest distances between interchain unco-
ordinated S atoms is 3.57 Å. Therefore, the molecular packing
of the complex forms a two-dimensional network structure
through S ؒ ؒ ؒ S contacts.4 Using ligands with multi-thioether
groups we have successfully obtained a silver() and copper()
co-ordination polymer.5
As one such ligand, hexakis(phenylsulfanyl)benzene (hphb)
is known to form host–guest compounds with CHCl3, CBrCl3,
C(CH3)Cl3, C(NO2)Cl3, C(CN)Cl3, CCl4, etc. MacNicol and co-
workers6 have reported that the hphb host shows remarkable
guest selectivity properties when recrystallized from solvent
mixtures. Also, Pang et al.7 have studied the orientation of the
guest molecules in host–guest compounds using hphb as the
host. Michalski et al.8 have discussed the crystal structure and
thermal expansion of a hphb–CBr4 clathrate. Recently, the
redox properties of polythiaarene derivatives and the crystal
structure of a diacetylene-linked polythiaarene have been
reported by Tucker et al.9 and Mayor et al.,10 respectively.
In this study hphb was used in place of hmb to synthesize
and characterize crystallographically the silver() co-ordination
polymer, and explore the effect of the substituent group on the
structure.
from Wako Chemical Co., Japan, and used without further
purification. The IR spectra were measured as KBr disks on a
JASCO FT/IR-8000 spectrometer, 1H NMR with a Varian
Marcury 300 FT-NMR spectrometer at 23 ЊC. Tetramethyl-
silane was used as the internal reference. Thermal gravimetry
(TG) analyses were obtained with a TG/DTA-200 and DSC-
200 instrument from the SEIKO Instrument Co. under nitrogen
at rates of 20 and 10 ЊC minϪ1, respectively. The curves for
complex 1 show a one-step decomposition behavior (366 ЊC),
corresponding to elimination of the hphb ligand. The melting
point (Tm) of the complex is 222 ЊC. After the complex had
been heated at 180 ЊC for 3 h under vacuum, DSC showed one
sharp Tm at 221 ЊC. This result indicates that the structure is
maintained during this heat treatment. On the other hand,
TG for complex 2 shows a two-step decomposition (254
and 401 ЊC), corresponding to the elimination of NO3Ϫ and the
hphb ligand. The Tm and decomposition temperature (Td) of
hphb are 189 and 417 ЊC, respectively.
Syntheses
Hexakis(phenylsulfanyl)benzene (hphb).11 In a three-necked
flask equipped with a magnetic stirring bar, septum cap
and argon gas inlet tube were placed 3.3 g (25.6 mmol) of
sodium benzenethiol (Aldrich Chemical Co., Inc.) and
25 cm3 of dry 1,3-dimethyl-2-imidazolidinone (Tokyo Chemical
Industry Co., Ltd.). To this suspension was added with stirring
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This journal is © The Royal Society of Chemistry 2000
DOI: 10.1039/b003944f

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0.50 g (0.3 cm3, 3.2 mmol) of hexafluorobenzene via a syringe
through the septum cap. The addition was at a relatively fast
rate, resulting in a mildly exothermic reaction. After 6 d at
60 ЊC, TLC (silica gel, 3:1 hexane–diethyl ether) showed only
one spot. At this point the reaction mixture was added to 100
cm3 of water and a yellow precipitate was filtered off and copi-
ously washed with water and sparingly with cold methanol to
yield 2.02 g (87%) of a yellow powder. Recrystallization from
chloroform–n-pentane yielded yellow brick crystals (0.91 g,
39%), mp 185–190 ЊC. IR (KBr disc): ν/cmϪ1 3067w, 3015w,
2936w, 1578s, 1476s, 1439m, 1267m, 1076m, 1024m, 997w,
1
901w, 741s, 700m and 689m. H NMR (300 MHz, CDCl3):
δH 6.9–6.95 (12 H, d) and 7.07–7.18 (18 H, m). EI Mass
spectrum: m/z 726 (100%, M).
[Ag2(hphb)][PF6]2 1. Single crystals suitable for X-ray analysis
were obtained by the reaction of AgPF6 (4.1 mg, 6 mmol)
dissolved in 5 cm3 of 2-butanone and a 2-butanone solution
(5 cm3) containing hphb (5.1 mg, 3 mmol). The mixture was
stirred for 1 h and the yellow filtrate transferred to a glass tube
and layered with 2 cm3 of n-pentane as the diffusion solvent.
After standing for 7 d at ambient temperature, yellow plate
crystals of complex 1 were isolated. Yield: 34% based on silver.
IR (KBr disc): ν/cmϪ1 3059w, 2926m, 2855w, 1580m, 1478m,
1441m, 1296, 1269, 1071w, 1024w, 999w, 849s, 741s, 687s and
559s (Found: C, 40.7; H, 2.7; S, 15.3. Calc. for C21H15AgF6PS3:
C, 40.9; H, 2.5; S, 15.6%).
Fig. 1 An ORTEP view of complex 1. Thermal ellipsoids are at the
50% probability level.
the planar Ag–S eight-membered ring, with another two
molecules below (Fig. 2(b)). Thus, complex 1 forms a pocket
structure. The Ag ؒ ؒ ؒ Ag distances in the Ag–S eight-membered
ring are 6.46 Å and the S ؒ ؒ ؒ S distances are 6.79 Å. The crystal
packing of complex 1 is shown in Fig. 3 (the PF6Ϫ anions, which
do not co-ordinate, are omitted for clarity). It was found that
the pocket structure has a regular arrangement and forms a
[Ag(hphb)(NO3)] 2. Crystals suitable for X-ray analysis were
obtained by procedures similar to those for complex 1. AgNO3
(6.4 mg, 5 mmol) was dissolved in 5 cm3 of THF and to this
solution was added a THF solution (5 cm3) containing hphb
(18.2 mg, 5 mmol) and layered with 2 cm3 of n-pentane as the
diffusion solvent. After standing for 3 d at ambient temperature
yellow prismatic crystals of complex 2 were isolated. Yield: 54%
based on silver. IR (KBr disc): ν/cmϪ1 3054m, 2973w, 2859w,
1580s, 1476s, 1439s, 1416s, 1372s, 1285s, 1180m, 1157w, 1071s,
1022s, 999m, 901w, 853w, 743s, 687s and 502m (Found: C,
56.3; H, 3.1; S, 21.2. Calc. for C42H30AgNO3S6: C, 56.2; H, 3.4;
S, 21.4%).
Ϫ
three-dimensional framework. Two PF6 anions occupy each
pocket. The side-phenyl groups of hphb are positioned so as
to avoid the pocket (Fig. 2(a)). We use descriptors a and b to
denote side-chain phenyl moieties projecting above or below,
respectively, the mean plane of the benzene core. The conform-
ation of hexakis(phenoxy)benzene and hphb have regular
alternating pairs of legs, ababab. The side-phenyl groups are
perpendicular to the benzene ring plane, however the con-
formation of hphb is abaabb (Fig. 1).
Linear chain of complex 2
Crystallography
The molecular structure together with the atomic numbering
scheme is given in Fig. 4. A single-crystal structure deter-
mination reveals that the co-ordination compound 2 contains
an infinite linear chain structure. In the cation all hphb units
are attached to the two silver centers by the S atoms except
for the para-positioned S atoms. The Ag–S distances are in the
range of 2.689–2.831 Å. Each silver ion is co-ordinated by
Crystal data for complexes 1 and 2 are given in Table 1. The
structures were solved by a direct method12 and refined by
full-matrix least-squares analysis on F2. Data collection was
performed on a Quantum CCD area detector coupled with a
Rigaku AFC-7R diffractometer. All the full-occupancy non-
hydrogen atoms were refined anisotropically. The positions of
all the hydrogen atoms were determined from difference
electron density maps and included, but not refined. Atomic
scattering factors and anomalous dispersion terms were taken
from the usual sources.13 Computations were carried out using
TEXSAN.14 Selected bond lengths and bond angles for 1 and
2 are listed in Table 2.
Ϫ
two hphb donors and one oxygen atom from a NO3 anion
in a distorted square pyramidal arrangement. The ligand acts
as a bridge between pairs of Ag atoms to produce a linear
chain polymer. The Ag(1)–O(1) distances are 2.395 Å. Six
phenyl groups are perpendicular to the core benzene ring
plane in complex 2, with regular alternating, ababab. Both the
linear chain structure and conformation of the ligand are the
same as in the Ag–hmb complex except for the co-ordination
number of Ag.
CCDC reference number 186/2158.
See http://www.rsc.org/suppdata/dt/b0/b003944f/ for crystal-
lographic files in .cif format.
Comparison between complex 1 and 2
Results and discussion
The co-ordination types of the silver() complexes with multi-S
substituted ligands are shown in Fig. 5. Using tetrakis(methyl-
sulfanyl)benzene, tetrakis(isopropylsulfanyl)-p-benzoquinone,16
hexakis(methylsulfanyl)benzene4 and hexakis(phenylsulfanyl)-
benzene (complex 2) as ligands, the crystal structures formed
is a linear chain of the co-ordination type shown in Fig. 5(a)
with alternating silver ions and ligands. In complex 1 all the
hphb units attached to the four silver centers by the S atoms
(Fig. 5(c)) interestingly form a three-dimensional structure with
pockets. The difference in complexation modes in complexes 1
Three-dimensional structure of complex 1
An ORTEP15 view of the complex, with selected atom labelling
is shown in Fig. 1. All hphb molecules are attached to the four
silver centers by the S atoms, and the silver ion has a tetrahedral
geometry. The Ag–S distances are in the range 2.557–2.606 Å,
which is comparable to that in the complexes of hmb with
silver() hexafluorophosphate [2.565(2) Å]. Four ligands are
arranged around the Ag–S eight-membered ring as shown in
Fig. 2(a). The two ligands on opposite sides are projected above
J. Chem. Soc., Dalton Trans., 2000, 3620–3623
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Fig. 2 Crystal structure of complex 1: (a) top view, (b) side view.
Fig. 4 An ORTEP view of complex 2 Thermal ellipsoids are at the
50% probability level.
possible crystal forms. In regular mode (ababab), it gives
a metal co-ordination polymer with linear structure. On the
other hand, in irregular mode (abaabb), it forms the strange
structure of Fig. 5(c). The Au(PPh3) complex with benzene-
hexathiol has been reported by Schmidbaur and co-workers.17
The [AuCS(PPh3)]6 complex forms a wheel-like structure
(Fig. 5(d)), however, the complex is not a co-ordination poly-
mer.18 As far as we are aware, there are a few examples of
metal carbonyl complexes with structures of the type shown in
Fig. 5(b).19
Ϫ
Fig. 3 Crystal packing of complex 1 (the PF6 anions, which do not
co-ordinate, are omitted for clarity).
and 2 relates to the conformations of the hphb side-phenyl
groups when recrystallized from solution. hphb has many
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J. Chem. Soc., Dalton Trans., 2000, 3620–3623

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Table 1 Crystallographic data for complexes 1 and 2
Acknowledgements
This work was partially supported by a Grant-in-Aid for
Scientific Research (c) (no. 12640547) from Japan Society for
the Promotion of Science. The authors thank Mr. K. Kitamura
and Mr. M. Anahata for their assistance with the X-ray
measurements.
1
2
Chemical formula
Formula weight
Crystal system
Space group
a/Å
b/Å
c/Å
α/Њ
C42H30Ag2F12P2S6
1232.72
Orthorhombic
I212121 (no. 24)
19.086(8)
19.060(1)
25.9042(7)
C42H30AgNO3S6
896.93
Triclinic
¯
P1 (no. 2)
9.302(1)
10.639(2)
21.118(6)
93.514(6)
92.144(3)
115.429(1)
1879.1(5)
2
References
1 M. Munakata, L. P. Wu and T. Kuroda-Sowa, Adv. Inorg. Chem.,
1999, 46, 173; J.-M. Lehn, Angew. Chem., Int. Ed. Engl., 1988, 27,
89; A. Muller, H. Reuter and S. Dillinger, Angew. Chem., Int. Ed.
Engl., 1995, 34, 2328; V. Balzani, Terahedron, 1992, 48, 10443;
E. C. Constable, Adv. Inorg. Chem., 1989, 34, 1; M. Munakata,
T. Kuroda-Sowa, M. Maekawa, A. Hirota and S. Kitagawa, Inorg.
Chem., 1995, 34, 2705.
β/Њ
γ/Њ
V/Å3
9423(3)
8
12.41
5721
5648
Z
µ(Mo-Kα)/cmϪ1
9.11
8072
8067
No. reflections measured
No. observed reflections
[I >10.00σ(I)]
R1
wR2
T/K
2 H.-P. Wu, C. Janiak, G. Rheinwald and H. Lang, J. Chem. Soc.,
Dalton Trans., 1999, 183; C. Kaes, M. W. Hosseini, C. E. F. Rickard,
B. W. Skelton and A. H. White, Angew. Chem., Int. Ed., 1998,
37, 920; P. K. Bowyer, K. A. Porter, A. D. Rae, A. C. Willis and
S. B. Wild, Chem. Commun., 1998, 1153; K. A. Hirsch, S. R. Wilson
and J. S. Moore, Chem. Commun., 1998, 13; C. B. Aakeroy and
A. M. Beatty, Chem. Commun., 1998, 1067; J. A. R. Navarro,
J. M. Salas, M. A. Romero and R. Faure, J. Chem. Soc., Dalton
Trans., 1998, 901; K. A. Hirsch, S. R. Wilson and J. S. Moore, Chem.
Eur. J., 1997, 3, 765; K. A. Hirsch, S. R. Wilson and J. S. Moore,
Inorg. Chem., 1997, 36, 2968; L. Carlucci, G. Ciani, D. W. v.
Gudenberg, D. M. Proserpio and A. Sironi, Chem. Commun.,
1997, 631; A. J. Blake, N. R. Champness, A. Khlobystov, D. A.
Lemenovskii, W.-S. Li and M. Schroder, Chem. Commun., 1997,
2027; L. Carlucci, G. Ciani, D. M. Proserpio and A. Sironi, Chem.
Commun., 1996, 1393; C. Janiak, T. G. Scharmann, P. Albrecht,
F. Marlow and R. Macdonald, J. Am. Chem. Soc., 1996, 118, 6307;
L. Carlucci, G. Ciani, D. M. Proserpio and A. Sironi, J. Am. Chem.
Soc., 1995, 117, 4562.
0.069
0.119
200.0
0.043
0.113
296.2
Table 2 Selected bond lengths (Å) and bond angles (Њ) for complexes 1
and 2
1
Ag(1)–S(1)
Ag(1)–S(5)
Ag(2)–S(2)
Ag(2)–S(4)
2.599(2)
2.561(3)
2.557(2)
2.600(2)
Ag(1)–S(2)
Ag(1)–S(6)
Ag(2)–S(3)
Ag(2)–S(5)
2.596(2)
2.606(2)
2.606(2)
2.600(2)
S(1)–Ag(1)–S(2)
S(1)–Ag(1)–S(6)
S(2)–Ag(1)–S(6)
S(2)–Ag(2)–S(3)
S(2)–Ag(2)–S(5)
S(3)–Ag(2)–S(5)
75.31(5)
108.81(6)
111.28(6)
77.98(5)
140.92(6)
111.29(6)
S(1)–Ag(1)–S(5)
S(2)–Ag(1)–S(5)
S(5)–Ag(1)–S(6)
S(2)–Ag(2)–S(4)
S(3)–Ag(2)–S(4)
S(4)–Ag(2)–S(5)
139.57(6)
140.97(6)
78.04(5)
139.59(6)
108.83(6)
75.37(5)
3 A. J. Blake, D. Collison, R. O. Gould, G. Reid and M. Schroder,
J. Chem. Soc., Dalton. Trans., 1993, 521; A. J. Blake, R. O. Gould,
G. Reid and M. Schroder, J. Chem. Soc., Chem. Commun., 1990,
974; A. J. Blake, G. Reid and M. Schroder, J. Chem. Soc., Chem.
Commun., 1992, 1074.
4 Y. Suenaga, T. Kuroda-Sowa, M. Munakata, M. Maekawa and
H. Morimoto, Polyhedron, 1998, 18, 429.
5 Y. Suenaga, M. Maekawa, T. Kuroda-Sowa, M. Munakata and
H. Morimoto, Acta Crystallogr., Sect. C, 1998, 54, 1566; Y. Suenaga,
T. Kuroda-Sowa, M. Maekawa and M. Munakata, J. Chem. Soc.,
Dalton Trans., 1999, 2737.
6 D. D. MacNicol and D. R. Wilson, J. Chem. Soc., Chem. Commun.,
1976, 494; A. D. U. Hardy, D. D. MacNicol and D. R. Wilson,
J. Chem. Soc., Perkin Trans. 2, 1979, 1011.
7 L. Pang, F. Brisse and E. A. C. Lucken, Can. J. Chem., 1995, 73, 351.
8 D. Michalski, M. A. White, P. K. Bakshi, T. S. Cameron and
I. Swainson, Can. J. Chem., 1995, 73, 513.
2
Ag(1)–S(1)
Ag(1)–S(4)
Ag(1)–O(1)
2.8313(7)
2.6892(6)
2.395(3)
Ag(1)–S(2)
Ag(1)–S(5)
2.6924(6)
2.7453(6)
S(1)–Ag(1)–S(2)
S(1)–Ag(1)–S(5)
S(2)–Ag(1)–S(4)
S(2)–Ag(1)–O(1)
S(4)–Ag(1)–O(1)
71.53(2)
97.00(2)
104.46(2)
78.75(6)
105.93(6)
S(1)–Ag(1)–S(4)
S(1)–Ag(1)–O(1)
S(2)–Ag(1)–S(5)
S(4)–Ag(1)–S(5)
S(5)–Ag(1)–O(1)
149.05(2)
103.31(6)
150.36(2)
71.08(2)
130.88(6)
9 J. H. R. Tucker, M. Gingras, H. Brand and J.-M. Lehn, J. Chem.
Soc., Perkin Trans. 2, 1997, 1303.
10 M. Mayor, J.-M. Lehn, K. M. Fromm and D. Fenske, Angew.
Chem., Int. Ed. Engl., 1997, 36, 2370.
11 C. W. Dirk, S. D. Cox, D. E. Wellman and F. Wudl, J. Org. Chem.,
1985, 50, 2395.
12 DIRDIF, Direct methods for Difference structures, an automatic
procedure for phase extension and refinement of difference structure
factors, P. T. Beurskens, Technical Report 1984/1, Crystallographic
Laboratory, Töernooiveld, Nijmegen, 1984.
13 International Tables for X-Ray Crystallography, Kynoch Press,
Birmingham, 1974, vol 4.
14 TEXSAN-TEXRAY, Structure Analysis Package, Molecular
Structure Corporation, The Woodlands, TX, 1985.
15 C. K. Johnson, ORTEP II, Report ORNL-5138, Oak Ridge
National Laboratory, Oak Ridge, TN, 1976.
16 Y. Suenaga, T. Kuroda-Sowa, M. Maekawa and M. Munakata, Acta
Crystallogr., Sect. C, 1999, 55, 1623.
17 H. K. Yip, A. Schier, J. Riede and H. Schmidbaur, J. Chem. Soc.,
Dalton Trans., 1994, 2332.
18 J. A. Harnisch and R. J. Angelici, Inorg. Chim. Acta, 2000, 300–302,
Fig. 5 Schematic view of metal co-ordination types with poly-thioether
substituted benzene.
273.
19 M. E. Peach and C. Burschka, Can. J. Chem., 1982, 60, 2029.
J. Chem. Soc., Dalton Trans., 2000, 3620–3623
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