Dipyrrin based silver [2 + 2] metallamacrocycles

Article abstract of DOI:10.1039/c0dt00907e

The synthesis and characterization of a series of [2 + 2] metallamacrocycles based on combinations of silver salts AgX (X = BF ₄^-, PF₆^-, SbF₆ ^-, TfO^-) with pyridyl, p-phenyl-pyri

Full text of DOI:10.1039/c0dt00907e

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PAPER
Dipyrrin based silver [2 + 2] metallamacrocycles†
Dmitry Pogozhev, Ste´phane A. Baudron* and Mir Wais Hosseini*
Received 23rd July 2010, Accepted 11th October 2010
DOI: 10.1039/c0dt00907e
The synthesis and characterization of a series of [2 + 2] metallamacrocycles based on combinations of
silver salts AgX (X = BF4 , PF6 , SbF6 , TfO-) with pyridyl, p-phenyl-pyridyl and p-phenyl-imidazolyl
appended dipyrrin (dpm) derivatives is reported. In these species, the silver ion is linearly coordinated
to one of the two pyrrolic groups of the dpm moiety through the nitrogen atom and to a N atom
belonging to the peripheral coordinating group. The organisation of the cyclic complexes in the solid
state is dependent on the nature of the anion X- and on the hydrogen bonding patterns formed with the
pyrrolic NH group, acting as a donor. Furthermore, in some cases, d10-d10 argentophilic interactions are
observed between consecutive macrocyclic complexes in the crystalline phase. The robustness of some
of the complexes obtained compounds was investigated by 1H- and 13C-NMR spectroscopy which
revealed the structural integrity of the cyclic species in solution. A DOSY NMR study on the cyclic
entity based on the imidazolyl appended dpm further assessed that the complex present in solution was
indeed the [2 + 2] metallamacrocycle.
-
-
-
Introduction
The design and preparation of metallamacrocycles, cyclic assem-
blies bearing endocyclic metal centres, have been the focus of a
large research effort over the past ca decade in response to their
potential applications in catalysis, optics or magnetism.1 This class
of molecules is obtained by combining metal centres offering at
least two vacant coordination sites with organic ligands bearing at
least two divergently oriented coordinating sites. Using different
organic ligands and metal centres, a large variety of architectures
such as triangles, squares, rectangles and polygons of higher
degree, polyhedra and cages1 as well as metallaorganic knots2 have
been prepared. Among the above-mentioned classes, molecular
rectangles, pertaining to the monocyclic category, belong to the
simplest architectures.1,3,4 Depending on the geometrical charac-
teristics of the organic ligand (orientation of the coordinating
sites) and of the available coordination sites on the metal centre,
a variety of metallamacrocycles of the [n + n] type with different
nuclearity may be generated (Fig. 1).
While a large number of examples reported is based on the
use of pyridyl containing ligands, polypyrrolic derivatives such as
porphyrin or dipyrrin (dpm) derivatives were also employed.5–8
While the latter class of bipyrrolic derivatives9 has received much
attention as ligands for the elaboration of heterometallic coordi-
nation polymers,10 examples of combinations of metal centers with
functionalized mono- or poly-dipyrrins leading to the formation
of triangles,6 rectangles7 and helices8 have also been reported. Re-
Fig. 1 Schematic representation of [n + n] (n = 1–4) metallamo-
nomacrocycles.
garding the combination of mono-dipyrrin derivatives with metal
centres, both the dipyrrin and its conjugate base have been shown
to form molecular rectangles.7 Heteroleptic complexes such as
(hfac)Cu(dpm) (hfac = hexafluoroacetylacetonate) or ZnCl(dpm)
incorporating the dipyrrinato ligand self-assemble into [2 + 2]
metallamacrocycles in order to complete the coordination sphere
around the metal centres (Scheme 1a).7a,c
To our knowledge, only one example of a metallamacrocycle
incorporating a non-deprotonated dipyrrin has been reported.7f
The cyclic complex is obtained upon association of a silver(I)
salt with a p-benzonitrile-bearing dpm derivative (Scheme 1a).
The silver ion is linearly coordinated to the nitrogen atom of
a pyrrolic ring and to the peripheral nitrile. Extension of this
approach to other para functionalized dipyrrins appeared to us as
an attractive strategy for the synthesis of a series of analogous [2 +
2] metallamacrocycles.
Laboratoire de Chimie de Coordination Organique, UMR CNRS 7140,
Universite´ de Strasbourg, F-67000, Strasbourg, France. E-mail: sbaudron@
unistra.fr, hosseini@unistra.fr; Fax: 33 368851325; Tel: 33 368851323
† CCDC reference numbers 791545–791554. For crystallographic data in
CIF or other electronic format see DOI: 10.1039/c0dt00907e
We report herein on such a study using combinations of
dipyrrins 1–3 (Scheme 2) and silver salts.
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Scheme 1 Metallamacrocycles based on functionalized dipyrrins: in non deprotonated form (a)7f or as a dipyrrinato chelate (b).7a
Scheme 2 Dipyrrins 1–3 and precursors 4 and 5 used in this study for the formation of [2 + 2] metallamacrocycles 6–12. For the complexes, the orientation
of the unbound pyrrole unit is arbitrarily drawn.
In this contribution, we have explored the use of
pyridyl and imidazolyl functionalized dipyrrins 1–3 to form
metallamacrocycles with a variety of silver salts such as AgBF4,
Results and discussion
Whereas dipyrrins 111 and 2, differing only by the presence of a
phenyl spacer in 2, are both based on a combination of the dpm
moiety and a pyridyl group, dipyrrin 3 contains a dpm unit and
an imidazolyl group which has been shown to coordinate silver
ion.10g
AgXF6 (X = P, Sb) and Ag(OTf).
Owing to the neutral nature of ligands 1–3, for the complexes
formed with silver salts AgX, one should keep in mind that, in the
solid state, their organization will also be influenced by the nature
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2+
Scheme 3 Different possible conformations of the free pyrrolic rings in the [2 + 2] metallamacrocycle [Ag(dpm-Ph-R)]2
.
of X- as well as by possible hydrogen bonding interactions with the
macrocycle. Indeed, the formation of a [2 + 2] metallamacrocycle,
such as the one presented in Scheme 1a for the p-benzonitrile
bearing dpm, requires the binding of the metal centre by one of
the two pyrrolic units. The remaining pyrrolic ring may behave as a
strong hydrogen bond donor. Furthermore, owing to its rotational
freedom, it can adopt different conformations depending on the
outward or inward orientation with respect to the macrocyclic
core (Scheme 3). Moreover, the known propensity of the silver
cation to generate argentophilic d10-d10 interactions,12 may also
contribute to the packing of the metallamacrocycles in the solid
state as already observed for the complex presented in Scheme
1a.7f
Table 1 Coordination bond distances and angles around silver ions in
macrocycles 6–12
˚
˚
Ag–Npyrrole/A
Ag–Npyridine/imid/A
N–Ag–N/◦
6
2.132(6)
2.127(9)
2.1475(19)
2.132(2)
2.127(3)
2.146(3)
2.121(2)
2.117(2), 2.128(2)
2.152(6)
2.131(8)
2.178(2)
2.153(2)
2.157(3)
2.168(3)
2.141(2)
2.115(2), 2.117(2)
169.7(2)
170.8(3)
165.30(8)
171.89(8)
169.37(11)
170.97(11)
171.15(19)
171.16(10), 174.74(10)
7
8
9
10
a-11
b-11
12
Dipyrrins 1 and 3 were prepared as described.10g,11 For the
synthesis of 2, the condensation of 4-(4-formylphenyl)pyridine, 4,
in neat pyrrole and in the presence of a catalytic amount of trifluo-
roacetic acid at 85 ◦C,11 afforded the intermediate dipyrromethane
5. The latter was oxidized into the desired compound 2 using DDQ
with an overall yield of 36% (Scheme 2).
Metallamacrocycles 6–12 (Scheme 2) were prepared by reacting
dipyrrins 1–3 with silver salts in benzene–MeCN, toluene–MeCN
or o-xylene/MeCN mixtures. Crystalline materials were obtained
at room temperature and in the absence of light after few days
upon slow evaporation of the solvent. Both the organization in
the solid state as well as the stability in solution of the prepared
compounds have been investigated by X-ray diffraction on single
crystal and by 1H-NMR respectively.
space group C2/c with one molecule in general position (Fig. 2b).
Owing to the electronic conjugation, the two pyrrolic rings are
almost c◦oplanar in both compounds (dihedral angle 4.21◦ for 2
and 6.76 for 3).10d,13 In contrast with the reported structure of 1,10d
in neither of the two structures, 2 and 3, were any strong hydrogen
bonds observed.
Macrocycle 6 (Scheme 2), composed of 1, Ag+ and TfO-,
crystallizes with three benzene molecules ([(1)Ag]2(OTf)2 (C6H6)3),
¯
in the triclinic space group P1. The ligand features an out-out
conformation (Fig. 3). The Ag+ cation, in a linear coordination
environment, is bonded to one nitrogen atom of a pyrrolic ring
and the pyridyl nitrogen atom of another molecule of 1 with bond
distances as expected for such compounds (Table 1).4 A long Ag–
˚
O distance of 2.755(7) A is observed with the triflate anion. Within
the macrocycle, the Ag+ cation is located above the pyridyl ring
˚
with the shortest Ag–C distance of 3.065(8) A, rather too long to
Crystal structures of dipyrrins 2 and 3 and of the [2 + 2] silver
metallamacrocycles 6–12
suggest any Ag–p interactions.14 The two Ag+ cations are distant
of 5.112(8) A. The pyrrolic NH pointing outward the macrocycle
˚
Dipyrrin 2 crystallized by slow diffusion of n-pentane vapours into
a CHCl3 solution of the ligand. It crystallizes in the monoclinic
space group P21/n with one molecule in general position (Fig. 2a).
The phenyl and pyridyl rings are not coplanar but form an angle
of 31.7◦. Dipyrrin 3 crystallized by slow diffusion of n-pentane
into a THF solution of the ligand. It crystallizes in the monoclinic
is hydrogen bonded to an oxygen atom of a triflate anion (dN–O
˚
=
2.907(9) A, aN–H—O = 148.7◦), leading thus to the formation of a
1D H-bonded network (Fig. 3).
Fig. 3 One-dimensional hydrogen bonding network formed upon bridg-
ing of consecutive matallamacrocycles 6 by triflate anions. Only NH
hydrogen atoms are presented for clarity.
In macrocycle 7, [(1)Ag]2(SbF6)2, ligand 1 adopts the in-in
Fig. 2 Crystal structure of dipyrrins 2 (a) and 3 (b). Hydrogen, carbon
and nitrogen atoms are in cyan, black and blue respectively.
conformation. Here again the Ag+ cation is in a linear coordination
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environment with Ag–N distances similar to the ones observed for
In macrocycle 9, [(2)Ag]2(OTf)2, ligand 2 adopts an out-out
conformation. The pyridyl and phenyl rings are not coplanar,
as in the structure of the precursor 2, but tilted with a dihedral
angle of 23.11◦. As for macrocycles 6–8, the silver cation is
in a linear coordination geometry with similar Ag–N distances
(Table 1). As in 6, one oxygen atom of the triflate anion weakly
˚
6 (Table 1). Long Ag–F distances of 2.896(8) and 2.936(8) A are
observed with the SbF6- anion. The pyrrolic N–H pointing inward
-
also interacts with the SbF6 anion via N–H—F hydrogen bonds
(dN–F = 3.095(9) A, aN–H—F = 176.8◦). This, again, leads to the
˚
formation of a 1D network (Fig. 4).
interacts with the Ag+ cation (dAg–O = 2.774(4) A) and is hydrogen
˚
˚
bonded to the pyrrolic NH pointing outward (dN–O = 2.873(4) A,
aN–H—O = 162.7◦). However, one salient difference between 6 and
˚
9 is the presence of a long Ag–Ag distance (3.627(5) A) between
neighbouring macrocycles, suggesting a d10-d10 interaction,12 as
observed in the structure of the reported analogue incorporating
the p-benzonitrile appended dpm.7f This leads to an overall 2D
architecture (Fig. 7).
Fig. 4 1D hydrogen bonding network formed by the metallamacrocycle
-
7 and SbF6 anion. Only NH hydrogen atoms are presented for clarity.
Macrocycle 8, [(1)Ag(H2O)]2(BF4)2, incorporates ligand 1 in an
in-out conformation. The Ag+ cation, as for 6 and 7, is coordinated
to a pyridyl and a pyrrolic nitrogen atom. However here the cation
˚
also binds a water molecule (dAg–O = 2.612(3) A) (Table 1). The
-
disordered BF4 anion is hydrogen bonded to the pyrrolic NH
(dN–F = 2.927(3) A, aN–H—F = 144.5◦) and to the water molecule
˚
˚
(dO–F = 2.694(3), 2.795(3), 2.834(3), 2.876(3) A) giving rise to a 3D
network (Fig. 5).
Fig. 7 2D organization of 9 in the crystalline phase. Only NH hydrogen
atoms are presented for clarity.
Macrocycle 10, [(2)Ag]2(PF6)2, crystallizes in the monoclinic
space group P21/n with one ligand 2, in an in-in conformation.
In this case, the phenyl and pyridyl rings are almost coplanar
with a 7.57◦ dihedral angle between them. As for 6–9, the silver
cation adopts a linear coordination environment with similar Ag–
-
N distances. The PF6 anion is hydrogen bonded to the pyrrolic
N–H pointing inward (dN–F = 2.971(4) A, aN–H—F = 146.4◦) (Fig.
˚
8). No extended network is observed in this structure.
Fig. 5 A portion of the 3D hydrogen bonding network formed by 8. Only
NH hydrogen atoms are presented for clarity. Note that only one position
-
of the disordered BF4 anion is shown.
Within this series of metallamacrocyles, no striking differences
in the geometry of the cyclic entity is observed (Fig. 6). This is
not surprising given that the most important degree of freedom is
in the angle between the coordinated pyrrolic and pyridyl rings.
The extension to ligand 2 featuring an additional phenyl ring
demonstrates the robustness of these cyclic species.
Fig. 8 Crystal structure of 10. Only NH hydrogen atoms are presented
for clarity.
Interestingly, depending on the solvent mixture used for crystal-
lization, upon combining ligand 2 with AgBF4, two polymorphs
were obtained. Upon slow evaporation of a benzene–MeCN mix-
ture, crystals of the a-11 polymorph (a-[(2)Ag]2(BF4)2 (MeCN)2)
were obtained. This phase crystallizes in the triclinic space group
Fig. 6 Comparison of the structures of the metallamacrocycles 6 (a), 7 (b)
and 8 (c) based on the same [(1)Ag]2 cationic motif. Only NH hydrogen
atoms are presented for clarity.
2+
440 | Dalton Trans., 2011, 40, 437–445
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¯
includes two ligands 3 adopting an out-out conformation. We
should note here that one TfO- anion and one MeCN solvent
molecule are disordered over two positions. Both Ag+ cations are
linearly coordinated to one pyrrolic and one imidazolyl nitrogen
atoms. One of the two triflate anions is hydrogen bonded to the
pyrrolic N–H donor of two different macrocycles leading thus to
P1 with ligand 2, in an in-in conformation. The phenyl and
pyridyl rings are almost coplanar as in 9. When the reaction was
performed in the toluene–MeCN system, a mixture of crystals of
a-11 and the b-11 was obtained. The latter phase crystallizes in
the monoclinic space group P21/n with ligand 2 also adopting
an in-in conformation. In both phases, a N–H—F hydrogen bond
˚
˚
a 2D arrangement (dN–O = 3.014(4) and 2.811(4) A, a(N–H—
is observed (dN–F = 2.812(6) and 2.970(5) A, aN–H—F = 167.6 and
O) = 154.3 and 155.2◦). This organization is further sustained by
154.7◦ for the a and b phases respectively). In none of the two
phases, extended hydrogen bonded networks are formed. The
major difference between the two polymorphs lies in the position
of the weakly coordinated acetonitrile molecules (dAg–N = 2.782(8)
the presence of d10-d10 interaction as in 9 (dAg–Ag = 3.435(10) A)
˚
(Fig. 11).12
˚
and 2.876(4) A for the a and b phases respectively). Indeed, in both
cases, the solvent molecule is located above and below the main
plane of the macrocycles. However, in the case of the a phase, they
are convergently oriented, whereas for the b phase, the reversed is
observed (Fig. 9).
Fig. 11 2D arrangement observed for the packing of the metallamacro-
cycle 12. Only NH hydrogen atoms are presented for clarity. Only one
position of the disordered triflate anion is shown for clarity.
Fig. 9 Comparison of the a and b polymorphs of 11.
Behaviour in solution
Interestingly, while metallamacrocyclic architectures could be
obtained in crystalline form upon combining the ligand 2 with
AgBF4, AgPF6 or AgOTf, the organization of the macrocycle
moiety as well as the orientation of the dpm ligand were found to
be rather different in the solid state. Indeed, the mutual orientation
of the phenyl and pyridyl rings spans from almost coplanar in 10
to rather twisted in 9. Furthermore, the relative orientation of the
coordinated pyrrolic and pyridyl rings varies as shown in Fig. 10.
These four crystal structures can be regarded as snapshots of some
It is worth noting that, for all cyclic structures 6–12, the aromatic
groups are in close van der Waals contact and thus these species
do not offer any internal cavity. This is substantiated by the large
displacement of the absorption peaks for the complexes with
respect to the free ligands 1–3.
The stability of metallamacrocycles 10 and 12 in acetone-d6
solution was investigated by 1H-NMR as representative examples
of the macrocyclic species obtained with ligands 2 and 3.
In the case of 10, bearing a phenyl spacer, a shift of the peaks
as well as the splitting of the signals corresponding to the pyrrolic
CH protons are observed indicating the survival of the complex
in solution. However, ca 5% of the free ligand 2 is observed
(Fig. 12). The same behaviour is observed for the macrocycle 12
incorporating the dipyrrin unit 3 (Fig. 13). However, in this case,
no decomposition was detected. Owing to the higher solubility of
compound 12 in acetone-d6, its stability could be also confirmed
in solution by 13C-NMR.
2+
of the conformations adopted by the macrocyclic core [(2)Ag]2
in solution (vide infra).
Fig. 10 Comparison of the structures of the metallamacrocycles 9 (a), 10
2+
(b), a-11 (c) and b-11 (d) based on the [(2)Ag]2 core. Only NH hydrogen
atoms are presented for clarity.
In the case of ligand 3, [2 + 2] metallamacrocycles were only ob-
tained upon reaction with AgOTf. Macrocycle 12 ([(3)Ag]2(OTf)2
(CH3CN)3) crystallizes with three CH3CN solvent molecules and
1
Fig. 12 Comparison of the aromatic region of the H-NMR spectra in
acetone d6 of ligand 2 and of the macrocycle 10.
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1
Fig. 13 Comparison of the aromatic region of the H-NMR spectra in
acetone d6 of ligand 3 and of the macrocycle 12.
Furthermore, for the complex 10, it has been shown that
the macrocyclic structure survived the presence of ca 5% of
coordinating CD3CN solvent in acetone-d6 solution.
Fig. 15 DOSY NMR spectrum of the macrocycle 12 in acetone d6.
It is worth noting that, although the NMR study clearly
indicates that both the dpm moiety and the peripheral group bind
simultaneously the silver cation, it does not allow to determine the
nuclearity of the complex. To get further insight into this point, a
DOSY NMR15 study in acetone-d6 was carried out on both ligand
3 and the macrocycle 12.
revealed that at least two of these cyclic structures, 10 and 12,
are rather robust in acetone-d6. Further work will focus on the
use of dipyrrin type ligands featuring a peripheral group in meta
position to favour the formation of macrocyclic architectures of
higher nuclearity and/or larger cavity size.
The determined diffusion coefficients of 1.637.103 and 1.061.103
mm2 s-1 for 3 and 12 respectively giving access to the hydrodynamic
radius of both compounds using the Stokes–Einstein equation,15
are in agreement with those calculated from the crystal structure
Experimental section
Synthesis
Pyrrole was purified over an alumina column before use. All other
reagents were obtained commercially and used without further
purification. 1H-and 13C-NMR spectra were acquired at 25 ◦C on
a Bruker AV 300 (300 MHz) with the deuterated solvent as the
lock and residual solvent as the internal reference. DOSY NMR
data were acquired on a Bruker 500 MHz spectrometer. NMR
chemical shifts are given in ppm and J values are given in Hz.
˚
(Fig. 14 and 15). The determined radius of 4.3 A for 3 compares
˚
well with the calculated one of 5.2 A. A better agreement is
observed for 12: 6.7 vs. 6.71 A. These results confirm that the
[2 + 2] macrocyclic structure pertains in solution.
˚
Dipyrromethane 5. Solid 4-(4-formylphenyl)pyridine (1.0 g,
5.45 mmol) was added to degassed pyrrole (20 mL, 288 mmol).
A few drops of TFA were added and the mixture was heated at
70 ◦C under argon in the absence of light for 24h. Pyrrole was then
removed under vacuum and the residue was dissolved in EtOAc
(100 mL). This solution was washed with 0.1 M NaOH (3 ¥ 50
mL) and water (3 ¥ 50 mL) and dried over MgSO4. Purification by
column chromatography (Al2O3, CH2Cl2) afforded 5 as a yellow
solid (0.896 g, 57%). dH(300 MHz, CDCl3) 8.61 (dd, J 1.5 and 4.4,
2H), 8.14 (br s, 2H), 7.58 (d, J 8.2, 2H), 7.47 (dd, J 1.5 and 4.4,
2H), 7.34 (d, J 8.2, 2H), 6.72 (dd, J 3.3 and 3.7, 2H), 6.17 (dd, J
3.7 and 5.7, 2H), 5.93 (m, 2H), 5.34 (s, 1H). dC(75 MHz, CDCl3)
150.1, 147.9, 143.4, 136.7, 132.1, 129.2, 127.2, 121.5, 117.5, 108.5,
107.4, 43.7. HRMS (ESI), m/z: [M + H]+ calcd for C20H18N3:
300.150, found 300.149.
Fig. 14 DOSY NMR spectrum of ligand 3 in acetone d6.
Dipyrrin 2. To a THF (75 mL) solution of dipyrromethane 5
(500 mg, 1.67 mmol) in an ice bath, DDQ (380 mg, 1.67 mmol) in
THF (75 mL was added dropwise. The solution quickly turned
dark. After stirring overnight, the mixture was evaporated to
dryness. Purification by column chromatography (Al2O3, CH2Cl2)
afforded compound 2 as a golden orange solid (320 mg, 64%).
dH(300 MHz, DMSO-d6) 12.65 (s, 1H), 8.69 (dd, J 4.5, and 1.6,
2H), 7.97–7.94 (m, 2H), 7.82 (dd, J 4.6 and 1.6, 2H), 7.78 (t, J
1.3, 2H), 7.63–7.61 (m, 2H), 6.54 (dd, J 4.2 and 1.0, 2H), 6.45
(dd, J 4.2 and 1.4, 2H). dC(75 MHz, DEPT, DMSO-d6) 150.8,
145.2, 131.8, 128.8, 126.8, 121.7, 118.5. lmax(CH2Cl2)/nm (e/mol-1
Conclusions
The foregoing result illustrate that dipyrrin ligands bearing
a peripheral coordinating groups are prone to form [2 + 2]
metallamacrocycles with different Ag(I) salts. The solid state
organization of these compounds are dependent on the nature
of the counter-ion forming hydrogen bonds with the remaining
pyrrolic NH group acting as a H-bond donor. Furthermore, in
some cases, additional d10-d10 interactions were also observed.
1
Solution studies by H-NMR as well as by DOSY experiments
442 | Dalton Trans., 2011, 40, 437–445
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Table 2 Crystallographic data for 2, 3, 6–8
2
3
6 (C6H6)3
7
8
Formula
FW
C20H15N3
297.35
C18H14N4
286.33
C48H40Ag2F6N4O6S2
1190.74
C28H26Ag2F12N6Sb2
1129.76
C28H26Ag2B2F8N6O2
867.91
Crystal system
Monoclinic
P21/n
11.1131(3)
7.2051(2)
19.4251(5)
Monoclinic
C2/c
12.8270(6)
12.5383(5)
18.6260(8)
Triclinic
P1
Monoclinic
C2/c
17.3749(9)
12.6487(6)
17.0711(8)
Monoclinic
P21/n
10.1379(2)
9.5859(2)
15.9091(4)
¯
Space group
˚
a/A
9.2123(4)
10.0695(5)
13.2746(6)
102.508(3)
93.810(3)
97.941(3)
1184.71(10)
1
173(2)
0.995
9920
5061 (0.0574)
0.0691
˚
b/A
˚
c/A
a (◦)
b (◦)
g (◦)
105.5270(10)
108.777(2)
118.616(2)
103.4170(10)
3
˚
V/A
1498.62(7)
4
173(2)
0.080
2836.2(2)
8
173(2)
0.083
3293.4(3)
4
173(2)
2.894
1503.86(6)
2
173(2)
1.392
Z
T/K
m/mm-1
Refls. coll.
Ind. refls. (Rint
11268
8513
13212
25736
)
3465 (0.0204)
0.0444
0.1167
0.0523
0.1227
1.049
3261 (0.0197)
0.0435
0.1080
0.0552
0.1154
1.027
3756 (0.0321)
0.0698
0.1206
0.0947
0.1289
1.219
3415 (0.0237)
0.0308
0.0674
0.0335
0.0690
1.124
R1 (I > 2s(I))a
wR2 (I > 2s(I))a
R1 (all data)a
wR2 (all data)a
GOF
0.1682
0.1111
0.2092
1.170
ꢀ
ꢀ
ꢀ
ꢀ
a R1 = ꢀFo| - |Fcꢀ/ |Fo|; wR2 = [ w(Fo2–Fc2)2/ wFo
]
.
4
1/2
Table 3 Crystallographic data for 9–12
9
10
a-11
b-11
12 (CH3CN)3
Formula
FW
Crystal system
C42H30Ag2F6N6O6S2
1108.58
C40H30Ag2F12N6P2
1100.38
Monoclinic
C44H36Ag2B2F8N8
C44H36Ag2B2F8N8
1066.17
Monoclinic
P21/n
10.5431(4)
7.2584(3)
C44H37Ag2F6N11O6S
1209.71
Monoclinic
1066.17
Triclinic
Triclinic
¯
¯
Space group
P1
P21/n
P1
P21/c
˚
a/A
9.8577(4)
11.1300(4)
11.5098(5)
118.0560(10)
92.695(2)
107.9120(10)
1032.41(7)
1
10.3668(3)
13.6996(4)
13.8058(4)
9.3120(3)
10.4615(3)
12.4452(4)
112.286(2)
94.953(2)
101.894(2)
1079.46(6)
1
12.7000(3)
20.4863(5)
18.5461(5)
˚
b/A
˚
c/A
27.3348(11)
a (◦)
b (◦)
g (◦)
95.6260(10)
93.822(2)
103.8480(10)
3
˚
V/A
1951.27
2
173(2)
1.184
2087.17(14)
2
173(2)
1.019
4685.0(2)
4
173(2)
1.010
Z
T/K
173(2)
1.134
12472
4690 (0.0281)
0.0336
0.0688
0.0430
0.0749
1.069
173(2)
0.985
16820
4916 (0.0269)
0.0449
0.1076
0.0496
0.1105
1.091
m/mm-1
Refls. coll.
Ind. refls. (Rint
22705
15348
49682
)
4497 (0.0292)
0.0405
0.1057
0.0531
0.1137
1.034
4798 (0.0267)
0.0366
0.0888
0.0533
0.0970
1.044
10775 (0.0327)
0.0386
0.0821
0.0485
0.0875
1.180
R1 (I > 2s(I))a
wR2 (I > 2s(I))a
R1 (all data)a
wR2 (all data)a
GOF
ꢀ
ꢀ
ꢀ
ꢀ
a R1 = ꢀFo| - |Fcꢀ/ |Fo|; wR2 = [ w(Fo2–Fc2)2/ wFo
]
.
4
1/2
L cm-1): 227 (29000), 256 (22000), 319 (15000), 438 (22000), 478
(15000). Found: C, 80.44; H, 5.28; N, 13.66. C20H15N3 requires C,
80.78; H, 5.08; N, 14.13.
Macrocycle6. From 1 (20mg, 0.090mmol) andAgOTf(23 mg,
0.090 mmol) in benzene. The product was obtained as red crystals
(22.4 mg, 41.6%) insoluble in common organic solvents.
Macrocycle 7. From 1 (20 mg, 0.090 mmol) and AgSbF6
(31 mg, 0.090 mmol) in o-xylene. Macrocycle 7 was obtained as red
crystals (34.3 mg, 67.2%) insoluble in common organic solvents.
Found: C, 29.63; H, 2.29; N, 7.42. C28H22Ag2F12N6Sb2 requires C,
29.77; H, 1.96; N, 7.44.
General procedure for the synthesis of macrocycles 6–12
A solution of ligand in 3 mL of benzene (o-Xylene) was mixed
with a 4 mL benzene (o-xylene) solution of AgX. After 1 min of
stirring, a red precipitate appeared. The reaction mixture was then
diluted with CH3CN (0.5–1.5 mL), until dissolution of the solid.
Slow evaporation in the absence of light afforded the macrocycles
as orange-red crystals.
Macrocycle 8. From 1 (20 mg, 0.090 mmol) and AgBF4 (18 mg,
0.090 mmol) in o-xylene. The product was isolated as red crystals
(24.0 mg, 61.2%). dH(300 MHz, Acetone-d6) 11.19 (s, 1H), 8.78
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(dd, J 4.6 and 1.7, 2H), 8.32 (s, 1H), 7.95 (dd, J 4.9 and 1.0, 1H),
7.91 (dd, J 4.6 and 1.7, 2H), 7.65–7.61 (m, 1H), 7.10 (dd, J 4.9 and
0.7, 1H), 6.87 (m, J 1.9, 1H), 6.60 (m, J 1.9, 1H). lmax(Acetone)/nm
(e/mol-1 L cm-1): 431 (39000). Found: C, 38.42; H, 3.22; N, 9.68.
C28H26Ag2B2F8N6O2 requires C, 38.75; H, 3.02; N, 9.68.
(c) G. F. Swiegers and T. J. Malefetse, Chem. Rev., 2000, 100, 3483–
3538; (d) M. Ruben, J. Rojo, F. J. Romero-Salguero, L. H. Huppadine
and J.-M. Lehn, Angew. Chem., Int. Ed., 2004, 43, 3644–3662; (e) M.
Fujita, M. Tominaga, A. Hori and B. Therrien, Acc. Chem. Res., 2005,
38, 369–380; (f) J. L. Boyer, M. L. Kuhlman and T. B. Rauchfuss,
Acc. Chem. Res., 2007, 40, 233–242; (g) G. Mezei, C. M. Zaleski and
V. L. Pecoraro, Chem. Rev., 2007, 107, 4933–5003; (h) E. Zangrando,
M. Casanova and E. Alessio, Chem. Rev., 2008, 108, 4979–5013; (i) B.
Therrien, Eur. J. Inorg. Chem., 2009, 2445–2453; (j) Y.-F. Han, W.-G.
Jia, W.-B. Yu and G.-X. Jin, Chem. Soc. Rev., 2009, 38, 3419–3434;
(k) B. H. Northrop, Y.-R. Zheng, K.-W. Chi and P. J. Stang, Acc. Chem.
Res., 2009, 42, 1554–1563.
Macrocycle9. From 2 (20mg, 0.067mmol)and AgOTf (17 mg,
0.067 mmol) in benzene. The product was obtained as red crystals
(19.5 mg, 52.3%). lmax(Acetone)/nm (e/mol-1 L cm-1): 445 (37000).
Found: C, 45.14; H, 3.05; N, 7.58. C42H30Ag2F6N6O6S2 requires C,
45.50; H, 2.73; N, 7.58.
2 (a) V. I. Sokolov, Russ. Chem. Rev., 1973, 42, 452; (b) D. M. Walba,
Tetrahedron, 1985, 41, 3161–3212; (c) K. S. Chichak, S. J. Cantrill, A.
R. Pease, S.-H. Chiu, G. W. V. Cave, J. L. Atwood and J. F. Stoddart,
Science, 2004, 304, 1308–1312; (d) C. Dietrich-Bucheker, B. X. Colasson
and J.-P. Sauvage, Top. Curr. Chem., 2005, 249, 261–283; (e) C. D.
Pentecost, K. S. Chichak, A. J. Peters, G. W. V. Cave, S. J. Cantrill and
J. F. Stoddart, Angew. Chem., Int. Ed., 2007, 46, 218–222; (f) J. Bourlier,
A. Jouaiti, N. Kyritsakas-Gruber, L. Allouche, J.-M. Planeix and M. W.
Hosseini, Chem. Commun., 2008, 6191–6193; (g) J. Guo, P. C. Mayers,
G. A. Breault and C. A. Hunter, Nat. Chem., 2010, 2, 218–222.
3 (a) R. Schneider, M. W. Hosseini, J.-M. Planeix, A. De Cian and J.
Macrocycle 10. From 2 (20 mg, 0.067 mmol) and AgPF6 (17
mg, 0.067 mmol) in benzene. Red crystals (24.7 mg, 66.7%). dH(300
MHz, Acetone-d6) 11.22 (s, 1H), 8.42 (dd, J 5.0 and 1.4, 2H), 8.26
(s, 1H), 8.14 (d, J 8.3, 2H), 7.89–7.87 (m, 3H), 7.78 (d, J 8.3,
2H), 7.64 (m, 1H), 7.07 (d, J 4.7, 1H), 6.90 (m, 1H), 6.64–6.61 (m,
1H). lmax(Acetone)/nm (e/mol-1 L cm-1): 440 (31000), 511 (15000).
Found: C, 43.47; H, 3.01; N, 7.45. C40H30Ag2F12N6P2 requires C,
43.66; H, 2.75; N, 7.64.
Fischer, Chem. Commun., 1998, 1625–1626; (b) M. Loı, M. W. Hosseini,
A. Jouaiti, A. De Cian and J. Fischer, Eur. J. Inorg. Chem., 1999, 1981–
1985; (c) A. Jouaiti, M. Lo¨ı, M. W. Hosseini and A. De Cian, Chem.
Commun., 2000, 2085–2086; (d) V. Jullien, M. W. Hosseini, J.-M. Planeix
and A. De Cian, J. Organomet. Chem., 2002, 643–644, 376–380; (e) P.
Grosshans, A. Jouaiti, M. W. Hosseini, A. De Cian and N. Kyritsakas-
Gruber, Tetrahedron Lett., 2003, 44, 1457–1460; (f) C. Klein, E. Graf,
M. W. Hosseini, A. De Cian and N. Kyritsakas-Gruber, Eur. J. Inorg.
Chem., 2003, 1299–1302; (g) P. Grosshans, A. Jouaiti, V. Bulach, J.-
M. Planeix, M. W. Hosseini and N. Kyritsakas, Eur. J. Inorg. Chem.,
2004, 453–458; (h) E. Deiters, V. Bulach and M. W. Hosseini, New J.
Chem., 2006, 30, 1289–1294; (i) S. A. Baudron and M. W. Hosseini,
Chem. Commun., 2008, 4558–4560; (j) J. Ehrhart, J-M. Planeix, N.
Kyritsakas-Gruber and M. W. Hosseini, Dalton Trans., 2009, 2552–
2557; (k) J. Ehrhart, J-M. Planeix, N. Kyritsakas-Gruber and M. W.
Hosseini, Dalton Trans., 2010, 39, 2137–2146.
¨
Macrocycle 11. From 2 (20 mg, 0.067 mmol) and AgBF4 (13
mg, 0.067 mmol) in benzene. Orange crystals (26.5 mg, 73.9%).
l
max(Acetone)/nm (e/mol-1 L cm-1): 442 (36000), 509 (8000).
Found: C, 49.44; H, 3.54; N, 10.39. C44H36Ag2B2F8N8 requires
C, 49.57; H, 3.40; N, 10.51.
Macrocycle 12. From 3 (30 mg, 0.105 mmol) and AgOTf (27
mg, 0.105 mmol) in benzene. Red crystals (43.3 mg, 68.0%). dH(400
MHz, Acetone-d6) 11.22 (s, 1H), 8.58 (s, 1H), 8.28 (s, 1H), 7.95
(d, J 8.3, 2H), 7.87 (t, J 1.5, 1H), 7.84 (d, J 4.6, 1H), 7.76 (d, J 8.3,
2H), 7.63 (s, 1H), 7.14 (s, 1H), 7.04 (d, J 4.7, 1H), 6.90 (d, J 3.4,
1H), 6.61 (t, J 3.0, 1H). dC(100 MHz, Acetone-d6) 160.9, 147.1,
146.2, 137.8, 137.2, 135.7, 134.6, 134.2, 132.0, 131.5, 131.0, 125.0,
125.1, 119.0, 118.0, 114.0. lmax(Acetone)/nm (e/mol-1 L cm-1): 453
(51000). Found: C, 41.89; H, 3.03; N, 10.48. C38H26Ag2F6N8O6S2
requires C, 42.08; H, 2.42; N, 10.33.
4 (a) D. Braga, M. Polito, M. Bracaccini, D. D’Addario, E. Tagliavini, D.
M. Proserpio and F. Grepioni, Chem. Commun., 2002, 1080–1081; (b) P.
L. Caradoc-Davies and L. R. Hanton, Dalton Trans., 2003, 1754–1758;
(c) C. S. Purohit and S. Verma, J. Am. Chem. Soc., 2006, 128, 400–
401; (d) T. Mochida, K. Okazawa and R. Horikoshi, Dalton Trans.,
2006, 693–704; (e) M. Maekawa, S. Kitagawa, T. Kuroda-Suowa and
M. Munakata, Chem. Commun., 2006, 2161–2163; (f) N. Sadhukhan,
S. K. Patra, K. Sana and J. K. Bera, Organometallics, 2006, 25, 2914–
2916; (g) N. L. S. Yue, M. C. Jennings and R. J. Puddephatt, Dalton
Trans., 2006, 3886–3893; (h) J.-S. Huang, J. Xie, S. C. F. Kui, G.-S. Fang,
N. Zhu and C.-M. She, Inorg. Chem., 2008, 47, 5727–5735; (i) S. De, M.
G. B. Drew, H. S. Rzepa and D. Datta, New J. Chem., 2008, 32, 1831–
1834; (j) L.-C. Song, G. X. Jin, L.-Q. Zhao, H.-T. Wang, W.-X. Zhang
and Q.-M. Hu, Eur. J. Inorg. Chem., 2009, 419–428; (k) J. Kumar and
S. Verma, Inorg. Chem., 2009, 48, 6350–6352; (l) N. Rani, G. K. Rao
and A. K. Singh, J. Organomet. Chem., 2009, 694, 2442–2447; (m) B.
J. Liddle, D. Hall, S. V. Lindeman, M. D. Smith and J. R. Gardinier,
Inorg. Chem., 2009, 48, 8404–8414; (n) N. L. S. Yue, M. C. Jennings
and R. J. Puddephatt, Dalton Trans., 2010, 39, 1273–1281; (o) J. Hu, J.
Zhao, Q. Guo, H. Hou and Y. Fan, Inorg. Chem., 2010, 49, 3679–3681.
5 (a) E. Iengo, E. Zangrando and E. Alessio, Acc. Chem. Res., 2006, 39,
841–851; (b) E. Deiters, V. Bulach and M. W. Hosseini, New J. Chem.,
2006, 30, 1289–1294.
X-Ray crystallography
Data (Tables 2 and 3) were collected on a Bruker SMART CCD
diffractometer with Mo-Ka radiation. The structures were solved
using SHELXS-97 and refined by full matrix least-squares on
F2 using SHELXL-97 with anisotropic thermal parameters for
all non hydrogen atoms. The hydrogen atoms were introduced at
calculated positions and not refined (riding model).
CCDC 791545-791554 contain the supplementary crystallo-
graphic data for compounds 2, 3, 6–12. These data can be obtained
free of charge via www.ccdc.cam.ac.uk/data_request/cif.
Acknowledgements
6 (a) A. Thompson, S. J. Rettig and D. Dolphin, Chem. Commun., 1999,
631–632; (b) C. Ikeda and T. Nabeshima, Chem. Commun., 2008, 721–
723.
We thank the Universite´ de Strasbourg, the Institut Universitaire
de France, the Ministry of Education and Research, the C.N.R.S.
and Marie Curie Est Actions FUMASSEC Network (Contract
N◦ MEST-CET-2005-020992) for financial support. We thank Dr
Lionel Allouche for the DOSY NMR experiment.
7 (a) J. M. Sutton, E. Rogerson, C. J. Wilson, A. E. Sparke, S. J. Archibald
and R. W. Boyle, Chem. Commun., 2004, 1328–1329; (b) S. R. Halper
and S. M Cohen, Angew. Chem., Int. Ed., 2004, 43, 2385–2388; (c) L.
Do, S. R. Halper and S. M. Cohen, Chem. Commun., 2004, 2662–2663;
(d) H. Maeda and T. Hashimoto, Chem.–Eur. J., 2007, 13, 7900–7907;
(e) L. Ma, J.-Y. Shin, B. O. Patrick and D. Dolphin, CrystEngComm,
2008, 1539–1541; (f) D. Salazar-Mendoza, S. A. Baudron and M. W.
Hosseini, Inorg. Chem., 2008, 47, 766–768; (g) H. Maeda, T. Hashimoto,
R. Fuji and M. Hasegawa, J. Nanosci. Nanotechnol., 2009, 9, 240–
248.
Notes and references
1 (a) P. J. Stang and B. Olenyuk, Acc. Chem. Res., 1997, 30, 502–518; (b) D.
L. Caulder and K. N. Raymond, Acc. Chem. Res., 1999, 32, 975–982;
444 | Dalton Trans., 2011, 40, 437–445
This journal is
The Royal Society of Chemistry 2011
©

View Article Online
8 (a) Y. Zhang, A. Thompson, S. J. Rettig and D. Dolphin, J. Am. Chem.
Soc., 1998, 120, 13537–13538; (b) A. Thompson and D. Dolphin, J. Org.
Chem., 2000, 65, 7870–7877; (c) Q. Chen, Y. Zhang and D. Dolphin,
Tetrahedron Lett., 2002, 43, 8413–8416; (d) Z. Zhang and D. Dolphin,
Chem. Commun., 2009, 6931–6933.
9 (a) C. Bru¨ckner, V. Karunaratne, S. J. Rettig and D. Dolphin, Can. J.
Chem., 1996, 74, 2182–2193; (b) R. W. Wagner and J. S. Lindsey, Pure
Appl. Chem., 1996, 68, 1373–1380; (c) T. E. Wood and A. Thompson,
Chem. Rev., 2007, 107, 1831–1861; (d) H. Maeda, Eur. J. Org. Chem.,
2007, 5313–5325; (e) S. A. Baudron, CrystEngComm, 2010, 12, 2288–
2295.
2254; (f) J. D. Hall, T. M. McLean, S. J. Smalley, M. R. Waterland
and S. G. Telfer, Dalton Trans., 2010, 39, 437–445; (g) D. Pogozhev,
S. A. Baudron and M. W. Hosseini, Inorg. Chem., 2010, 49, 331–
338.
11 B. J. Littler, M. A. Miller, C.-H Hung, R. W. Wagner, D. F. O’Shea,
P. D. Boyle and J. S. Lindsey, J. Org. Chem., 1999, 64, 1391–
1396.
12 P. Pyykko¨, Chem. Rev., 1997, 97, 597–636.
13 (a) J.-Y. Shin, B. O. Patrick and D. Dolphin, CrystEngComm, 2008, 10,
960–962; (b) D. Salazar-Mendoza, S. A. Baudron and M. W. Hosseini,
CrystEngComm, 2009, 11, 1245–1254.
10 (a) S. R. Halper and S. M. Cohen, Inorg. Chem., 2005, 44, 486–488; D.
L. Murphy, M. R. Malachowski, C. F. Campana and S. M. Cohen,
Chem. Commun., 2005, 5506–5508; (b) S. R. Halper, L. Do, J. R.
Stork and S. M. Cohen, J. Am. Chem. Soc., 2006, 128, 15255–15268;
(c) S. Garibay, J. R. Stork, Z. Wang, S. M. Cohen and S. G. Telfer,
Chem. Commun., 2007, 4881–4883; (d) J. R. Stork, V. S. Thoi and S. M.
Cohen, Inorg. Chem., 2007, 46, 11213–11223; (e) D. Salazar-Mendoza,
S. A. Baudron and M. W. Hosseini, Chem. Commun., 2007, 2252–
14 (a) E. A. Hall Griffith and E. L. Amma, J. Am. Chem. Soc., 1974, 96,
743–749; (b) K. Shelly, D. C. Finster, Y. J. Lee, R. Scheidt and C. A.
Reed, J. Am. Chem. Soc., 1985, 107, 5955–5959; (c) M. Munakata, L.
P. Wu and G. L. Ning, Coord. Chem. Rev., 2000, 198, 171–203; (d) S.
V. Lindeman, R. Rathore and J. K. Kochi, Inorg. Chem., 2000, 39,
5707–5716.
15 Y. Cohen, L. Avram and L. Frish, Angew. Chem., Int. Ed., 2005, 44,
520–554.
This journal is
The Royal Society of Chemistry 2011
Dalton Trans., 2011, 40, 437–445 | 445
©