Catenanes built around octahedral transition-metal complexes that contain two intertwined endocyclic but non-sterically hindering tridentate ligands

Article abstract of DOI:10.1002/chem.201104061

Sterically hindering bidentate chelates, such as 2,9-diphenyl-1,10- phenanthroline, form entwined complexes with copper(I) and other tetrahedrally coordinated transition-metal centres. To prepare octahedral complexes containing two entwined tridentate lig

Full text of DOI:10.1002/chem.201104061

FULL PAPER
DOI: 10.1002/chem.201104061
[2]Catenanes Built Around Octahedral Transition-Metal Complexes that
Contain Two Intertwined Endocyclic but Non-sterically Hindering Tridentate
Ligands
Jean-FranÅois Ayme,[a] Jacques Lux,[a] Jean-Pierre Sauvage,*[a, b] and Angꢀlique Sour*[a]
Abstract: Sterically hindering bidentate
chelates, such as 2,9-diphenyl-1,10-phe-
nanthroline, form entwined complexes
with copper(I) and other tetrahedrally
coordinated transition-metal centres.
To prepare octahedral complexes con-
taining two entwined tridentate ligands
and thus apply a strategy similar to
that used for making catenanes with
tetrahedral metal centres, the use of
the classical terpy ligand (terpy=
2,2’:6’,2’’-terpyridine) appears to be at-
tractive. In fact, 6,6’’-diphenyl-2,2’:6’,2’’-
terpyridine (dp-terpy) is not appropri-
ate due to strong “pinching” of the or-
ganic backbone by coordination to the
metal and thus stable entwined com-
plexes with this ligand cannot be ob-
tained. Herein, we report the synthesis
and coordination properties of a new
family of tridentate ligands, the main
features of which are their endocyclic
nature and non-sterically hindering
character. The coordinating fragment
consists of two 8’-phenylisoquinolin-3’-
yl groups attached at the 2 and 6 posi-
tions of a pyridine nucleus. Octahedral
complexes containing two such entan-
gled ligands around an octahedral
metal centre, such as FeII, RuII or CoIII,
are highly stable, with no steric conges-
tion around the metal. By using func-
tionalised ligands bearing terminal ole-
fins, double ring-closing metathesis
leads to [2]catenanes in good yield with
FeII or CoIII as the templating metal
centre. The X-ray crystallography
structures of the FeII precursor and the
FeII catenane are also reported. These
show that although significant pinching
of the ligand is observed in both FeII
complexes, the system is very open and
no steric constraints can be detected.
Keywords: catenanes · entwined li-
gands
· isoquinoline · transition
metals · tridentate ligands
Introduction
using catalytic amounts of a transition-metal complex in-
stead of stoichiometric quantities. Traditionally, copper(I)—
generally considered to be a tetrahedrally coordinated metal
centre—has been the metal of choice as the template and
even as the “active template”, in association with one or
two bidentate ligands, although other transition metals (pal-
ladium, in particular) have also been utilised.
Octahedral transition-metal complexes have also been
used in the traditional approach, when the function of the
metal centre is purely structural, most of the time with re-
markable success in terms of simplicity and the efficiency of
the synthesis.[18,25–30] Particularly interesting work by Leigh
and co-workers was reported ten years ago,[19a] which
showed that a large variety of octahedral metal centres can
indeed be used as very efficient templates when used in con-
junction with two entangled tridentate ligands. In recent re-
ports, we described the remarkable properties of a new
family of bidentate ligands based on the 8,8’-diphenyl-substi-
tuted 3,3’-biisoquinoline fragments (dpbiiq). These frag-
ments are crescent shaped, thereby allowing the incorpora-
tion of such ligands in a ring with an endocyclic coordina-
tion site, and at the same time they have a very open coordi-
nation site. The dpbiiq-type ligands are thus simultaneously
endocyclic and non-sterically hindering.[27,39]
Transition metals have played and continue to play a very
important role in the synthesis of catenanes and rotax-
anes.[1–18] The first high-yielding template synthesis, reported
long ago,[10] was based on copper(I), which is able to bind
two bidentate coordinating fragments so as to generate
a two-component entanglement, that is, a precursor to
a [2]catenane. Transition metals have been amply used by
various groups to prepare a large variety of interlocking-
ring compounds.[11–30] More recently, an important extension
has been reported, named the “active metal template”,
which consists of using the metal as both a structural ele-
ment able to gather and orient the various organic frag-
ments to be incorporated in the catenane backbone and a re-
agent or even a catalyst for the last step of the synthesis,
namely the ring-closing reaction for catenanes or the stop-
per-fixing step for rotaxanes.[31–38] This last approach paves
the way for the synthesis of interlocking compounds by
[a] J.-F. Ayme, Dr. J. Lux, Dr. J.-P. Sauvage, Dr. A. Sour
Laboratoire de Chimie Organo-Minꢀrale, Institut de Chimie
University de Strasbourg-CNRS/UMR7177
4 rue Blaise Pascal, 67070 Strasbourg Cedex (France)
Fax : (+33)368851637
We would now like to report that this concept can be ex-
tended to tridentate chelating groups incorporating two sub-
stituted isoquinoline fragments attached to a central pyri-
dine nucleus. The archetypal tridentate ligand of this type is
E-mail: jpsauvage@unistra.fr
[b] Dr. J.-P. Sauvage
Present address: ISIS, 8 allꢀe Gaspard Monge
University of Strasbourg, 67000 Strasbourg (France)
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5565

2,6-di(8’-phenylisoquinolin-3’-yl)pyridine
(dpiq-py;
see
Scheme 1). By complexing two such compounds to an octa-
hedral transition-metal centre (RuII, FeII or CoIII), an entan-
glement is formed that contains two highly entwined organic
fragments, with no strain or congestion around the metal,
thanks to the non-sterically hindering nature of the ligands.
From the entanglement obtained, [2]catenanes can be pre-
pared in high yield.
Results and Discussion
Design: Although complexes containing two 6,6’’-diphenyl-
2,2’:6’,2’’-terpyridine (dp-terpy) fragments coordinated to
a transition metal may appear to be attractive targets to
generate entanglements, the dp-terpy ligand is not well
adapted to the formation of entwined complexes due to the
steric repulsion between the aromatic groups borne by the
first terpyridine nucleus and the terpyridine core of the
second dp-terpy unit. By coordination to a metal centre, this
problem is made even more acute by the “pinching effect”
originating from coordination of the three pyridine nuclei of
a terpy ligand. This problem is illustrated in Scheme 1. The
Scheme 1. a) Generation of a two-component entanglement and synthesis
of a [2]catenane based on tridentate ligands and an octahedral transition
metal as the template; b) By coordination to a metal centre M, the whole
ligand structure is pinched and the two phenyl rings of the dp-terpy che-
lating compound come closer together. As a consequence, severe steric
repulsion occurs between various aromatic fragments within the complex;
c) In contrast, even if the same “pinching” process is observed when co-
ordinating a dpiq-py ligand to a metal, the distance between the two
phenyl rings of the same ligand is such that there is no steric repulsion
with the other ligand, making the corresponding complexes highly stable.
In addition, the entanglement is particularly well adapted to the forma-
tion of a [2]catenane, because the extremities of each tridentate chelating
group are located considerably beyond the metal centre, forcing the two
future rings to be interlocked with one another.
main reason for the steric congestion found in [MACTHUNTGRNEUNG(dp-
terpy)2]n+ complexes (M=octahedral transition-metal
centre) is simply that the angles between the axes of the
three pyridine nuclei are not the same in the free ligand as
in its complexes. Due to coordination to the metal atom,
each terpy ligand is “pinched” and the two phenyl-ring axes
are no longer parallel, which creates steric repulsion as indi-
cated in Scheme 1. As shown many years ago, dp-terpy is
Acyclic precursors and analogues: Our goal was first to syn-
thesise a tridentate ligand containing two anisyl groups.
These two substituents can subsequently be modified to give
a cyclised ligand when coordinated to a metallic centre. The
unable to form stable [M
only example that has been found is the ruthenium(II) com-
plex [Ru
(dp-terpy)2]2+, which seems to be stable in the dark
(dp-terpy)2]n+ complexes.[40–41] The
ACHTUNGTRENNUNG
G
tridentate ligand 2,6-diACTHNGUTERNNU[G 8’-(para-anisyl)isoquinolin-3’-yl]pyri-
but undergoes an efficient photochemical ligand-substitution
reaction, leading to release of strain by de-coordinating the
two lateral pyridine nuclei from the metal upon irradiation
with light.[41] Owing to a complete lack of steric hindrance
between the various parts of the complex, the new ligand
dpiq-py is perfectly adapted to the formation of entangle-
ments consisting of two tridentate aromatic ligands for
which the coordination mode is similar to that of terpy.
dine 4 was prepared in two steps (Scheme 2) from anisyltri-
flate derivative 1.[39] Substitution of the triflate group with
a trimethylstannane group was performed with hexamethyl-
ditin in the presence of [PdACHTNUGTRNEUNG(PPh3)4] as the catalyst and po-
tassium iodide, which inhibits reductive elimination of the
OTf functional group. The expected product 2 was obtained
in 80% yield. A Stille cross-coupling of compound 2 with
diiodopyridine 3 in the presence of [Pd
tate ligand 4 in 58% yield.
ACHTUNGTRENUN(NG PPh3)4] gave triden-
Scheme 2. Synthesis of ligand 4 and the corresponding FeII and RuII complexes
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[2]Catenanes
FULL PAPER
The coordination chemistry of the new ligand 4 was then
studied with iron(II) and ruthenium(II) salts. Complexation
Table 1. Comparison of selected bond lengths [ꢂ] and angles [8] within
the coordination spheres of [Fe(4)2)]
N
ACHTUNGTRENNUNG
[a]
N
ACHTUNGTRENNUNG[PF6]2
with [Fe
ACHTUNGTRENNUNG
red complex [Fe(4)2)]AHCTUNTGRENNUNG
À
Fe N bond lengths
with the central N atoms
with the lateral N atoms
axial N-Fe-N angles
1.883
1.975
1.879
1.980
after purification by silica gel column chromatography. The
complexation reaction with RuII needed harsher conditions.
Thus, it was performed in ethylene glycol under microwave
irradiation And the product was purified by silica gel
with the central N atoms
with the lateral N atoms
intra-ligand O–O separations
178.92
162.82
8.536
179.15
161.82
8.010
column chromatography, providing the dark red complex
1
8.300
[Ru(4)2)]
N
two complexes showed typical chemical shifts for the pro-
tons, characteristic of the complexation of two entwined li-
gands around the metal centre.
[a] Average values.
Crystals of the iron(II) complex suitable for X-ray crystal-
lography were grown by diffusion of isopropyl ether in ace-
tone. No strong stacking interactions have been observed
between two neighbouring molecules in the unit cell. The X-
ray structure (Figure 1) gives information about the octahe-
dral environment of the iron(II) metal centre, and about the
bly, this significant distortion, which will of course facilitate
intra-ligand cyclisation reactions, does not lead to any con-
straint around the metal centre because the aromatic groups
involved (anisyl groups) are attached to the tridentate
ligand at positions that are remote from the metal coordina-
tion sphere.
strong pinching of the ligands (2,6-diACHTUNTRGNEUNG[8’-(para-anisyl)isoqui-
nolin-3’-yl]pyridine) around the metal centre.
FeII and CoIII complexed [2]catenanes:
Synthesis of tridentate ligand 7; the precursor to the catenane:
Tridentate ligand 7 was prepared in two steps from ligand 4
(Scheme 3). Deprotection of the anisyl groups in ligand 4,
by using pyridinium chloride and microwave irradiation at
ambient pressure, gave diphenol 5 in a quantitative yield. A
double Williamson reaction between diphenol 5 and the to-
sylated chain (2-allyloxyethoxy)tosylsulfonate (6, obtained
in a one-step reaction from commercially available allyloxy-
Figure 1. Different views of the X-ray structure of [Fe(4)2]ACTHNUTRGNE[UGN PF6]2. Atoms
in the second half of the molecule are related to the first by inversion
through a centre of symmetry.
AHCTUNGTRENGNeUN thanol) gave ligand 7 in 72% yield.
Synthesis of the FeII complexes: Ligand 7 was treated with
half an equivalent of iron(II) ions to generate the octahedral
complex [Fe(7)2]2+ (Figure 2). After addition of an excess of
saturated aqueous KPF6 solution, the precursor complex
was obtained as its hexafluorophosphate salt in 92% yield.
1H NMR spectroscopy provided clear evidence that the
The coordination sphere around the FeII centre is slightly
distorted. The distances between the N atoms and the iron
atom are more or less normal (see Table 1). As expected,
the central atom of each tridentate ligand is significantly
closer to the Fe atom than the peripheral N atoms (1.883 ꢂ
and 1.975 ꢂ, respectively). The Ncentral-Fe-Ncentral atom angle
is close to ideal (178.928), whereas the Nperipheral-Fe-Nperipheral
angle is, as expected, much smaller than that of an ideal oc-
tahedron (162.828).
1
complex is diamagnetic. It also presented H chemical shifts
characteristic of octahedral complexes containing two en-
twined ligands. In particular protons H1, adjacent to the iso-
quinolyl nitrogen atoms, are shifted upfield by about
1.75 ppm upon complexation (Figure 3). This observation is
in agreement with the formation of a complex in which the
Finally, and probably particularly importantly, coordina-
tion of a metal, such as FeII, to
ligand 4 induces a very strong
“pinching” of the organic back-
bone, bringing the two oxygen
atoms in each ligand into close
proximity (8.536 ꢂ). The angle
between the two anisyl-ring
axes (each axis is defined as the
straight line joining the oxygen
atom borne by the phenyl ring
and the carbon atom para to
this
O
atom, MeO-Ph-) is
roughly equal to 198. Remarka- Scheme 3. Synthesis of the tridentate ligand 7.
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5567

A. Sour, J.-P. Sauvage et al.
Figure 2. FeII and CoIII acyclic complexes and catenanes.
Figure 4. X-ray crystal structure of [Fe(9)]ACHTNUGTRNEG[UN PF6]2.
line joining the oxygen atom borne by the phenyl ring and
the carbon atom para to this O atom) is roughly equal to
238, that is, very strongly pinched. It appears to be more
pinched than in the open system [Fe(4)2)]ACHTUNTRGNEUNG[PF6]2 (“entwined
Figure 3. 1H NMR spectra of ligand
7
(top) and complex [Fe(7)2]2+
complex”), which indicates that cyclisation has an effect on
the geometry and brings the two oxygen atoms borne by the
lateral aromatic groups closer to one another (see Table 1
and Figure 1). Interestingly, one of the ligands is significant-
ly more pinched than the other (O–O separations of 8.010
and 8.300 ꢂ, respectively). As for the precursor, the two -O-
Ph- fragments are too far away to perturb the coordination
sphere of the FeII centre.
(bottom) in CDCl3. The numbering scheme is shown in Schemes 2 and 3.
H1 protons are located in the shielding cone of the central
pyridine ring of the opposite ligand.
Cyclisation of this precursor complex by ring-closing
metathesis (RCM) of its terminal olefins was performed in
dichloromethane at room temperature in the presence of
the first-generation Grubbs catalyst.[42] The double ring-clo-
sure reaction gave catenane [Fe(8)]2+ as a dark-red solid in
75% yield after purification by column chromatography on
alumina. The signals for the terminal olefins (6.13, 5.48 and
5.34 ppm) disappeared, whereas those for cyclic olefins ap-
peared at 6.19 and 6.08 ppm as a mixture of cis (88%) and
trans (12%) isomers, integrating for four protons.
Synthesis of the CoIII complexes: Because ligand exchange
around CoIII centres is very slow and difficult, it is common
to assemble the ligands around CoII ions and then lock the
system by oxidation to CoIII. Reaction of ligand 7 with a co-
balt(II) salt, followed by oxidation with cerium(IV) and
anion exchange with KPF6 afforded the octahedral complex
The catenane [Fe(8)]2+ was then hydrogenated under an
H2 atmosphere with Pd/C (10 mol% Pd) as the catalyst, in
a 1:1 mixture of CH2Cl2 and EtOH at room temperature.
The purified reduced catenane [Fe(9)]2+ was obtained in
[Co(7)2]ACHTNUGRTNEUNG[PF6]3 (Figure 2) in 72% yield as an orange solid.
1
The H NMR spectrum of [Co(7)2]3+ is sharp and well re-
solved, showing a low-spin and diamagnetic state, as expect-
ed for CoIII–polypyridine derivatives. As for the analogous
1
99% yield, as its PF6 salt. H NMR spectroscopy showed the
1
complete disappearance of the olefinic signals and appear-
ance of two new signals at 3.86 and 1.99 ppm, corresponding
to the new methylene protons.
iron complex [Fe(7)2]2+, the H NMR spectrum showed that
protons H1 adjacent to the nitrogen atoms are strongly shift-
ed upfield, which is a signature of the entwined structure of
the corresponding complex.
The molecular structure of the iron(II) catenane [Fe(9)]-
A
The double ring-closing metathesis, performed under the
same reaction conditions as for the iron(II) analogue, was
incomplete and extra Grubbs catalyst was necessary to close
the two rings. Furthermore, the cobalt ions were partially re-
duced during this metathesis reaction, it was, thus, necessary
to treat the solution with CeIV at the end of the RCM reac-
The crystal was a racemic twin, as suggested by the Flack
parameter of 0.55(2). The catenane has roughly the same co-
ordination sphere as the entwined precursor. The main dif-
ference lies in the pinching effect. The angle between the
two “anisyl” ring axes (each axis is defined as the straight
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[2]Catenanes
FULL PAPER
tion to obtain the CoIII catenane. Purification by chromatog-
raphy on alumina and anion exchange with KPF6 afforded
versible one-electron reduction wave at À0.87 V, which for-
mally corresponds to the CoII/CoI process.[45]
the catenane [Co(8)]ACHTNUTRGNEUNG[PF6]3 as a yellow powder in 70% yield.
1
The H NMR spectrum showed two signals corresponding to
the cis and trans olefinic protons, in a 3:1 ratio.
UV/Vis absorption spectroscopy: The UV/Vis absorption
spectra of the complexes [Ru(4)2]2+, [Fe(4)2]2+, [Fe(9)]2+
and [Co(9)]3+ are depicted in Figure 5. The absorption
maxima and molar absorption coefficients are collected in
Table 3. The absorption spectra of the complexes are charac-
terised by three distinct zones: 1) the ultraviolet region
below 300 nm shows intense bands that can be assigned to
1p–p* ligand-centred transitions; 2) various absorption
bands are observed in the region between 300 and
Reduction of the double bonds under the usual conditions
was also incomplete. Hydrogenation of the double bonds
with H2 required equimolar quantities of the Pd/C catalyst.
As in the RCM reaction, the resulting solution was the
treated with CeIV. This oxidation reaction was followed by
anion exchange with KPF6 to afford the final catenane
[Co(9)]ACHTUNGTRENNUNG[PF6]3 in 60% yield.
The electrospray mass spectrum of each CoIII complex
showed a peak corresponding to [MÀ3PF6]3+. A second
peak corresponding to [MÀ2PF6]2+, the intensity of which
was not negligible, was also present, although the NMR
spectrum showed that these complexes were fully diamag-
netic. The CoII peaks probably originate from partial reduc-
tion of the complex in the mass spectrometer source.[43]
400 nm,[50] which are likely to correspond to n–p* and intra-
1
ligand charge-transfer (1ILCT) transitions; and 3) the ab-
sorption bands in the visible region of the spectra are as-
signed to metal-to-ligand charge-transfer (MLCT) bands, in
agreement with previous reports on related complexes.[19,51]
Although the classical [RuACHTNUGRTNEUNG
(terpy)2]2+ chromophore shows
one MLCT band centred at 475 nm,[46] it is interesting to
Physical properties:
Electrochemistry: The redox behaviour of complexes
[Ru(4)2]2+, [Fe(4)2]2+, [Fe(9)]2+ and [Co(9)]3+ was analysed
by using cyclic voltammetry. The redox potentials of the var-
ious complexes are collected in Table 2, the ligand-based re-
Table 2. Electrochemical data versus SCE.[a]
M3+/M2+ [V]
(DEp [mV])
M3+/M2+ [V]
ACHTUNGTRENNUNG
[Ru(4)2]2+
[Fe(4)2]2+
[Fe(9)]2+
[Co(9)]3+
1.17 (82)
1.07 (60)
1.08 (73)
0.18 (85)
[Ru
[Ru
N
1.14[47]
1.28[46]
[Fe
A
1.13[44, 48]
0.16[19, 44,45]
[Co
AHCTUNGTRENNUNG
[a] Oxidation potentials (vs. SCE) measured by cyclic voltammetry of the
RuII, FeII and CoIII complexes. Conditions for the four new complexes:
acetonitrile/dichloromethane (9:1), against Ag+/AgCl electrode and ref-
erenced to ferrocene as 0.5 V, by using 0.1m nBu4NPF6 as the electrolyte,
n=200 mVsÀ1
.
duction processes could only be observed on the anodic
sweep, with very poorly resolved waves. The return peaks
were generally masked by intense adsorption waves. The
four complexes show typical reversible metal-centred redox
processes, in agreement with the literature data (see
Table 2). As expected, the electrochemical properties are
mainly ruled by the choice of metal and only very weakly by
the ligand. Indeed, the ruthenium(II) complex shows a rever-
sible oxidation wave around 1.2 V, and the FeIII/FeII redox
potentials are observed around 1.1 V. By contrast, the CoIII/
CoII potential is observed at a much lower value (E1/2
=
0.18 V vs. SCE), in accordance with other cobalt polypyri-
dine compounds.[19,44,45]
The cyclic voltammograms of the ruthenium and iron
complexes show one or two irreversible one-electron reduc-
tion peaks around À1.40 V. These can be assigned to ligand-
based reductions.[48] The cobalt complex shows a quasi-re-
Figure 5. UV/Vis absorption spectra of the complexes [Ru(4)2]2+ (blue),
[Fe(4)2]2+ (red), [Fe(9)]2+ (green) and [Co(9)]3+ (purple) in acetonitrile
at room temperature.
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A. Sour, J.-P. Sauvage et al.
Table 3. Absorption data in acetonitrile for the four complexes, at room temperature.
(300 MHz), a Bruker AVANCE 400 (400 MHz) or a Bruker
AVANCE 500 (500 MHz) spectrometer. 2D ROESY spectra
were measured by using a Bruker AVANCE 500 (500 MHz)
spectrometer. The spectra were referenced to residual proton-
ated solvent references (1H: CDCl3: 7.24; CD3CN: 1.94;
[D6]DMSO: 2.50; CD2Cl2: 5.32 ppm). Mass spectra were ob-
tained by using a Bruker MicroTOF (MS (ES)) spectrometer
or a Bruker Daltonics autoreflex II TOF/TOF spectrometer
with dithranol as the matrix (MALDI). UV/Vis absorption
spectra were performed by using a Kontron UVIKON 860
lmax [nm] (e [mÀ1 cmÀ1])
[Ru(4)2]2+
[Fe(4)2]2+
[Fe(9)]2+
[Co(9)]3+
246 (69900)
247 (89100)
248 (70600)
247 (132400)
317 (30600)
291 (38400)
290 (30200)
–
359 (38100)
368 (44800)
369 (35000)
374 (39500)
426 (9000)
449 (8700)
451 (6600)
–
466 (6700)
541 (6100)
542 (4700)
–
note that complex [Ru(4)2]2+ shows two MLCT bands at
466 and 426 nm. The same feature is observed for the
iron(II) analogue. Furthermore, the MLCT bands for the
iron(II) complexes appear redshifted with respect to the
ruthenium complex, which is in agreement with previous re-
ports on related complexes[50] and which simply indicates
spectrophotometer. Cyclic voltammetry experiments were performed by
using an EG&G Princeton Applied Research 273 A potentiostat, a Pt
working electrode, a Pt wire as a counter electrode, a silver wire as
a pseudo-reference electrode and a 0.1m solution of Bu4NPF6 in MeCN/
CH2Cl2 (9:1) as the supporting electrolyte. Potentials are quoted versus
the ferrocene/ferricenium couple (E0ACTHNUTRGNEUNG
(Fc+/Fc0)=0.4 V vs. SCE) and all
the redox potentials were referenced to internal ferrocene added at the
end of each experiment.
that FeII is easier to oxidise than RuII. The cobalt
ACTHUNTGRENNG(U III) com-
X-ray structure solution and refinement: Single-crystal X-ray diffraction
experiments were carried out by the service of the University of Stras-
bourg (Dr. Lydia Brelot). The crystals were placed in oil, and a single
crystal was selected, mounted on a glass fibre and placed in a low-tem-
plex shows an absorption band at 374 nm, the exact nature
of which is uncertain. These absorptions are responsible for
the orange colour of the complex, and their wavelength cor-
responds to that observed in the literature.[19,52]
perature N2 stream. CCDC-847292 ([Fe(4)2]
ACHTUGNTRENUN[GN PF6]2) and CCDC-847293
([Fe(9)][PF6]2) contain the supplementary crystallographic data for this
AHCTUNGTRENNUNG
paper. These data can be obtained free of charge from The Cambridge
Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
Conclusion
Conditions for the entwined iron(II) complex: X-ray diffraction data col-
lection was carried out on a Nonius Kappa-CCD diffractometer equipped
with an Oxford Cryosystem liquid N2 device by using MoKa radiation
(l=0.71073 ꢂ). The crystal–detector distance was 36 mm. The cell pa-
rameters were determined (Denzo software)[53] from reflections taken
from one set of 10 frames (1.08 steps in phi angle), each at 20 s exposure.
The structure was solved by direct methods using the program SHELXS-
97.[54] The refinement and all further calculations were carried out by
using SHELXL-97.[55] The H atoms were included in calculated positions
and treated as riding atoms by using SHELXL default parameters. The
non-H atoms were refined anisotropically by using weighted full-matrix
least-squares on F2. One of the methyl groups is disordered over two po-
sitions. The SQUEEZE instruction in PLATON[56] was applied. The re-
sidual electron density was assigned to one molecule of acetone and one
molecule of isopropyl ether. The structures were drawn by using Mercu-
ry.
Ligands derived from 2,6-di(8’-para-anisylisoquinolin-3’-yl)-
pyridine are particularly well adapted to the formation of
highly stable entwined complexes with octahedral transition
metal centres. These aromatic compounds constitute an al-
ternative to the terpy tridentate chelate that, in contrast to
the present series of molecules, cannot form entangled com-
plexes when substituted at the nitrogen atom a positions
due to steric repulsion. Interestingly, in spite of the strongly
pinched geometry of the coordinated ligands, there is no sig-
nificant steric hindrance between the lateral aromatic frag-
ments borne by a given chelate and the coordinating core of
the other ligand. The reason for this is that the distance be-
tween the two attachment points of the lateral groups onto
the tridentate unit itself is very large (c.a. 10.5 ꢂ), which
allows distortion without repulsion. The new tridentate
ligand described in this report and the corresponding macro-
cycles incorporating this unit will be used to elaborate
future molecular machines based on 5-coordinate or octahe-
dral transition-metal centres.
Conditions for the entwined iron(II) catenane: X-Ray diffraction data col-
lection was carried out on a Bruker APEX II DUO Kappa-CCD diffrac-
tometer equipped with an Oxford Cryosystem liquid N2 device by using
MoKa radiation (l=0.71073 ꢂ). The crystal–detector distance was
38 mm. The cell parameters were determined (APEX2 software)[5] from
reflections taken from three sets of 12 frames, each at 10 s exposure. The
structure, refinement and calculations were solved as described above. A
semi-empirical absorption correction was applied by using SADABS in
APEX2;[57] transmission factors: Tmin/Tmax =0.6582/0.7456. The structure
was treated as a racemic twin solved within the P212121 space group with
a BASF of 0.54975.
Experimental Section
[8-(para-Anisyl)isoquinolin-3-yl]trimethylstannane
(2):
Compound
1 (437 mg, 1.14 mmol) was placed in a two-necked round-bottom flask
(50 mL) in the presence of hexamethyldistannane (747 mg, 2.28 mmol),
potassium iodide (378.5 mg, 2.28 mmol) and tetrakis(triphenylphosphi-
ne)palladium(0) (63.6 mg, 0.057 mmol). Dimethoxyethane (24 mL) was
then added and the reaction was heated at reflux (908C) for 18 h. After
cooling and evaporation of the solvents (stannyl byproducts were neutral-
ised with KOH in ethanol), the resulting residue was dissolved in diethyl
ether and impurities were filtered off. The solvent was evaporated and
compound 2 was obtained as a yellow oil (363 mg, 80%). 1H NMR
(CDCl3, 300 MHz): d=9.44 (s, 1H), 7.82 (fine d, 1H, J=1.1 Hz), 7.69 (s,
1H), 7.67 (dd, 1H, J=7.4, 6.7 Hz), 7.44 (dd, 1H, J=7.4, 1.7 Hz), 7.41 (d,
2H, J=8.8 Hz), 7.02 (d, 2H, J=8.8 Hz), 3.87 (s, 3H), 0.38 ppm (s, 9H).
General: Some solvents were distilled over the appropriate drying agent:
tetrahydrofuran and diethyl ether over sodium and benzophenone, di-
chloromethane over calcium hydride, and triethylamine over potassium
hydroxide. Anhydrous DMF was used as received. Thin-layer chromatog-
raphy (TLC) was performed by using glass sheets coated with silica or
neutral alumina. Column chromatography was carried out on silica gel
(Kieselgel 60, 0.063–0.200 mm, Merck) or alumina (aluminium oxide 90
standardised or acid, 0.063–0.200 mm, Merck). All reactions were carried
out under an argon atmosphere and in oven-dried glassware. 8-(para-
Anisyl)isoquinolin-3-yl trifluoromethanesulfonate 1 was synthesised ac-
cording to a procedure described previously by our group.[39]
Instrumentation: Proton nuclear magnetic resonance (1H NMR and
2,6-Di
ACHTUNGTNER[NUNG 8’-(para-anisyl)isoquinolin-3’-yl]pyridine (4): 2,6-Diiodopyridine
2D COESY) spectra were acquired on either a Bruker AVANCE 300
(3; 63 mg, 0.27 mmol), tetrakis(triphenylphosphine)palladium(0) (37 mg,
5570
www.chemeurj.org
ꢁ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2012, 18, 5565 – 5573

[2]Catenanes
FULL PAPER
0.033 mmol) and stannyl derivative 2 (217 mg, 0.55 mmol) were placed in
The combined organic layers were dried and evaporated. The residue
was purified by chromatography on silica gel by using dichloromethane/
methanol (100:0 to 100:2) as the eluent. Compound 6 was obtained as
a yellow oil (603 mg, 95%). 1H NMR (CDCl3, 300 MHz): d=7.81 (d,
2H, J=8.2 Hz), 7.35 (d, 2H, J=8.1 Hz), 5.82 (m, 1H), 5.18 (m, 1H), 4.17
(t, 2H, J=4.7 Hz), 3.95 (td, 2H, J=5.7, 1.46 Hz), 3.62 ppm (t, 2H, J=
4.9 Hz); MS (ES): m/z calcd for C5H10O2Na: 125.057 [M+Na+]; found:
125.056.
a
two-necked round-bottom flask (50 mL) and dissolved in toluene
(11 mL). The resulting mixture was heated at reflux for 24 h. The sol-
vents were evaporated (stannyl byproducts were neutralised with KOH
in ethanol) and the residue was dissolved in dichloromethane. Distilled
water was added and the organic phase was separated off. The aqueous
phase was extracted twice with CH2Cl2. The combined organic phases
were evaporated and the residue purified by chromatography on Al2O3
by using dichloromethane/pentane (2:1) as the eluent to afford pure com-
2,6-DiACHTNUTRGNE[NUG 8’-(para-allyloxyethoxyphenyl)isoquinolin-3’-yl]pyridine (7): Com-
1
pound 8 as a white solid (85 mg, 58%). H NMR (CDCl3, 300 MHz): d=
pound 5 (60 mg, 0.116 mmol) and Cs2CO3 (226 mg, 0.696 mmol) were dis-
solved in dry DMF (5 mL). The solution was stirred at 608C for 30 min.
Compound 6 (90 mg, 0,548 mmol) was added and the mixture was heated
to 758C for 16 h. The solvent was evaporated and the residue dissolved
in dichloromethane. Distilled water was added and the organic phase was
separated off. The aqueous phase was extracted twice with CH2Cl2. The
combined organic phases were evaporated and the residue purified by
chromatography on Al2O3 by using dichloromethane/pentane (3:2 to
pure dichloromethane) as the eluent to give 7 as a white solid (57 mg,
72%). 1H NMR (CDCl3, 300 MHz): d=9.47 (s, 2H; H1), 9.11 (s, 2H;
H4), 8.55 (d, 2H, J=7.8 Hz; Hpy1), 8.08 (d, 2H, J=8.1 Hz; H5), 8.01 (t,
1H, J=7.9 Hz; Hpy2), 7.79 (dd, 2H, J=7.6, 7.2 Hz; H6), 7.57 (d, 2H, J=
7.2 Hz; H7), 7.53 (d, 4H, J=8.8 Hz; Ho), 7.13 (d, 4H, J=8.8 Hz; Hm),
6.00 (ddt, 2H, J=16.5, 10.5, 5.4 Hz; Hc4), 5.35 (dd, 2H, J=16.5, 1.5 Hz;
Hc5), 5.25 (dd, 2H, J=10.5, 1.4 Hz; Hc6), 4.26 (t, 4H, J=5.0; Hc1), 4.16
(d, 4H, J=5.4 Hz; Hc3), 3.89 ppm (t, 4H, J=5.0 Hz; Hc2); MS (ES): m/z
calcd for C45H39N3O4: 686.301 [M+H+]; found: 687.252.
9.46 (s, 2H; H1), 9.10 (s, 2H; H4), 8.54 (d, 2H, J=7.8 Hz; Hpy1), 8.07 (d,
2H, J=8.1 Hz; H5), 8.00 (t, 1H, J=7.8 Hz; Hpy2), 7.77 (dd, 2H, J=7.2,
7.2 Hz; H6), 7.54 (d, 2H, J=7.2 Hz; H7), 7.51 (d, 4H, J=8.6 Hz; Ho),
7.08 (d, 4H, J=8.6 Hz; Hm), 3.91 ppm (s, 6H; HMe); MALDI-MS: m/z
calcd for C37H27N3O2: 545.2182; found: 545.476.
[Fe(4)2]
bottom flask (25 mL) under argon and (partially) dissolved in dichloro-
methane (5 mL). A solution of [Fe(BF4)2]·6H2O (4.9 mg, 0.015 mmol) in
ACHTUNGTRENNUNG[PF6]2: Ligand 4 (16 mg, 0.029 mmol) was placed in a round-
AHCTUNGTRENNUNG
acetonitrile (3 mL) was added and the solution was stirred at room tem-
perature for 2 h. After this time, all solvents were evaporated and the
residue was purified by column chromatography on SiO2 with acetone/
H2O/KNO3 (100:5:0.2; saturated solution of KNO3) as the eluent. After
an anion exchange reaction, [Fe(4)2]ACHTNUTRGNEUGN[PF6]2 was obtained as a red solid
(21 mg, 99%). Crystals were obtained by diffusion of diisopropyl ether in
acetone. 1H NMR (CD2Cl2, 500 MHz): d=9.28 (s, 4H; H4), 9.15 (d, 4H,
J=8.1 Hz; Hpy1), 8.67 (t, 2H, J=8.1 Hz; Hpy2), 8.05 (s, 4H; H1), 8.04 (d,
4H, J=7.0 Hz; H5), 7.80 (dd, 4H, J=7.0, 7.0 Hz; H6), 7.53 (d, 4H, J=
7.0 Hz; H7), 7.10 (d, 8H, J=8.6 Hz; Ho), 6.98 (d, 8H, J=8.6 Hz; Hm),
4.09 ppm (s, 12H; HMe); MS (ES): m/z calcd for [C74H54N6O4Fe+H+]:
573.1774 [M+H+]; found: 573.1643.
[Fe(7)2]
bottom flask (25 mL) and dissolved in dichloromethane (11 mL). A solu-
tion of [Fe(BF4)2]·6H20 (11.6 mg, 0.0343 mmol) in acetonitrile (7 mL) was
ACHTUGNTRENN[UNG PF6]2: Compound 7 (47 mg, 0.069 mmol) was placed in a round-
AHCTUNGTRENNUNG
added and the reaction was stirred at room temperature for 2 h. After
this time, all solvents were evaporated and the residue was purified by
chromatography on Al2O3 by using dichloromethane/methanol (100:4) as
the eluent. After evaporation of the collected fractions, the solid was dis-
solved in dichloromethane, a saturated aqueous solution of KPF6 (4 mL)
was added, the organic solvent was evaporated and the precipitate was
[Ru(4)2]ACHTUNGTRENNUNG[PF6]: Ligand 4 (10 mg, 0.018 mmol) and [RuCl2ACHTUNGRNET(NUGN dmso)4]
(4.4 mg, 0.009 mmol) were placed in a pear-shaped flask (5 mL) under
argon and ethylene glycol (3 mL) was added. The mixture was then
heated in a microwave oven (three times 5 min with maximum power
500 W). A saturated solution of KPF6 in water (15 mL) was then added,
and the precipitate formed was filtered and washed copiously with water.
The residue was purified by chromatography on SiO2 with acetone/H2O/
KNO3 (50:5:0.5; saturated solution of KNO3) as the eluent. After an
collected by filtration. The compound [Fe(7)2]ACHTNUGTRNEUNG[PF6]2 was obtained as
1
a red solid (54.7 mg, 92%). H NMR (CDCl3, 300 MHz): d=8.92 (s, 4H;
H4), 8.79 (d, 4H, J=8.1 Hz; Hpy1), 8.41 (t, 2H, J=8.1 Hz; Hpy2), 8.04 (d,
4H, J=8.4 Hz; H5), 7.72 (m, 8H; H1, H6), 7.45 (d, 4H, J=7.2 Hz; H7),
7.08 (d, 8H, J=8.6 Hz; Ho), 6.77 (d, 8H, J=8.6 Hz; Hm), 6.13 (ddt, 4H,
J=17.2, 10.8, 5.7 Hz; Hc4), 5.48 (dd, 4H, J=17.2, 1.3 Hz; Hc5), 5.34 (d,
4H, J=10.8 Hz; Hc6), 4.51 (m, 8H; Hc1), 4.31 (d, 8H, J=5.7 Hz; Hc3),
4.09 ppm (m, 8H; Hc2); MS (ES): m/z calcd for C90H78N6O8Fe: 713.261
[M/2]; found: 713.238.
anion exchange reaction, [Ru(4)2]ACHTNUGTRNEUNG[PF6]2 was obtained as a dark-red solid
(10 mg, 75%). Crystals were obtained by slow diffusion of diisopropyl
ether in acetone. 1H NMR ([D6]acetone, 300 MHz): d=9.37 (s, 2H; H4),
9.09 (d, 4H, J=8.1 Hz; Hpy1), 8.57 (t, 2H, J=8.1 Hz; Hpy2), 8.31 (s, 4H;
H1), 8.11 (d, 4H, J=8.2 Hz; H5), 7.86 (dd, 4H, J=8.2, 7.4 Hz; H6), 7.61
(d, 4H, J=7.4 Hz; H7), 7.06 (d, 8H, J=9.4; Ho), 7.03 (d, 8H, J=9.4;
Hm), 4.05 ppm (s, 12H; HMe); MS (ES): m/z calcd for
[C74H54N6O4Ru+H+]: 596.1630 [M+H+]; found: 596.1748.
[Fe(8)]ACTHNUTRGENN[UG PF6]2: Complex [Fe(7)2]ACHTUGNTERN[NUGN PF6]2 (54.7 mg, 0.032 mmol) was dis-
solved in dichloromethane (40 mL) at room temperature to obtain
a 0.0008m solution. A solution of the catalyst (Grubbs I ruthenium car-
bene, 2.6 mg, 10 mol%) in dichloromethane (1 mL) was then added and
the mixture was stirred for 16 h at room temperature. The solvent was
evaporated and the residue was purified by chromatography on Al2O3 by
using dichloromethane/methanol (100:4) as the eluent to give catenane
2,6-DiACHTUNGTRENNUNG(8’-(para-hydroxyphenyl)isoquinolin-3’-yl)pyridine (5): A large
excess of pyridinium chloride (around 50 equiv) was added to compound
4 (230 mg, 0,42 mmol) in a round-bottom flask. The reaction mixture was
heated at reflux with a microwave oven for 10 min. The heating was car-
ried out twice more after addition of the same amount of pyridinium
chloride. The solid residue was taken up with water (50 mL) and the so-
lution was neutralised to pH 7–8 by using 33% aqueous ammonium hy-
droxide. The suspension was then filtered and washed with water. The re-
covered solid was dried under vacuum overnight to give pure compound
[Fe(8)]ACHTUNGTRNEUNG
[PF6]2 in 75% yield (39.9 mg). 1H NMR (CDCl3, 300 MHz): d=
8.92 (s, 4H; H4), 8.81 (d, 4H, J=8.1 Hz; Hpy1), 8.41 (t, 2H, J=8.1 Hz;
Hpy2), 8.06 (d, 4H, J=8.4 Hz; H5), 7.73 (m, 4H; H6), 7.68 (s, 4H; H1),
7.47 (d, 4H, J=7.2 Hz; H7), 7.10 (d, 8H, J=8.6 Hz; Ho), 6.79 (d, 8H, J=
8.6 Hz; Hm), 6.19 (s, 3.5H; Hc4cis), 6.08 (s, 0.5H; Hc4trans), 4.53 (m, 8H;
Hc1), 4.38 (s, 8H; Hc3), 4.14 ppm (m, 8H; Hc2); MS (ES): m/z calcd for
C86H74N6O8Fe: 687.245 [M/2]; found: 687.252.
1
5 (213 mg, 98%). H NMR (DMSO, 300 MHz): d=9.39 (s, 2H; H1), 9.35
(s, 2H; H4), 8.58 (d, 2H, J=7.9 Hz; Hpy1), 8.28 (d, 2H, J=8.1 Hz; H5),
8.19 (t, 1H, J=7.9 Hz; Hpy2), 7.97 (dd, 2H, J=7.5, 7.5 Hz; H6), 7.66 (d,
2H, J=7.0 Hz; H7), 7.49 (d, 4H, J=8.6 Hz; Ho), 7.02 ppm (d, 4H, J=
8.6 Hz; Hm).
[Fe(9)]ACHTUNRTGENNG[U PF6]2: Catenane [Fe(8)]ACHTUGNTRNE[NUGN PF6]2 (38.5 mg, 0.0232 mmol) was dis-
solved in a 1:1 mixture of CH2Cl2/EtOH (50 mL). The catalyst (Pd/C
10 mol%, 0.125 mg) was then added and the resulting mixture was stirred
overnight under an H2 atmosphere. The solvent was evaporated and the
residue was purified by chromatography on Al2O3 by using dichlorome-
thane/methanol (100:4) as the eluent. After evaporation of the solvent
from the collected fractions, the solid was dissolved in dichloromethane,
a saturated aqueous solution of KPF6 (4 mL) was added, the organic sol-
vent was evaporated and the precipitate was collected by filtration. The
(2-Allyloxyethoxy)-para-toluenesulfonate
(6):
2-Allyoxyethanol
(0.27 mL, 0.253 g, 2.48 mmol), 4-dimethylaminopyridine (18.2 mg,
0.15 mmol) and triethylamine (1.72 mL, 1.25 g, 12.38 mmol) were dis-
solved in dry dichloromethane (10 mL). After cooling to 08C, para-tolue-
nesulfonyl chloride (1.18 g, 6.19 mmol) was added in small portions to
the reaction mixture. The mixture was then allowed to warm to room
temperature overnight. The reaction mixture was acidified to pH 3 with
10% aqueous HCl and the product was extracted with dichloromethane.
catenane [Fe(9)]ACHTNUTRGNEUNG[PF6] was obtained in almost quantitative yield (38.5 mg,
Chem. Eur. J. 2012, 18, 5565 – 5573
ꢁ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
5571

A. Sour, J.-P. Sauvage et al.
1
99%). H NMR (CDCl3, 300 MHz): d=8.94 (s, 4H; H4), 8.81 (d, 4H, J=
was obtained as
a
yellow powder in 60% yield (24 mg). 1H NMR
(CDCl3, 300 MHz): d=9.12 (s, 4H; H4), 8.78 (d, 4H, J=7.8 Hz; Hpy1),
8.64 (t, 2H, J=7.8 Hz; Hpy2), 8.13 (d, 4H, J=8.4 Hz; H5), 7.99 (dd, 4H,
J=7.5, 7.8 Hz; H6), 7.73 (d, 4H, J=7.0 Hz; H7), 7.64 (s, 4H; H1), 7.09 (d,
8H, J=8.6 Hz; Ho), 6.97 (d, 8H, J=8.6 Hz; Hm), 4.34 (m, 8H; Hc1), 3.98
(m, 8H; Hc2), 3.83 (m, 8H; Hc3), 1.96 ppm (m, 8H; Hc4); UV/Vis (aceto-
8.1 Hz; Hpy1), 8.39 (t, 2H, J=8.1 Hz; Hpy2), 8.04 (d, 4H, J=8.1 Hz; H5),
7.72 (s, 4H; H1), 7.68 (d, 4H, J=7.8 Hz; H6), 7.44 (d, 4H, J=6.6 Hz; H7),
7.06 (d, 8H, J=8.6 Hz; Ho), 6.75 (d, 8H, J=8.6 Hz; Hm), 7.06 (d, 8H, J=
8.6 Hz), 4.42 (m, 8H), 4.06 (m, 8H), 3.86 (m, 8H), 1.99 ppm (m, 8H);
UV/Vis (acetonitrile): lmax (e)=542 (4670), 451 (6540), 369 (34950), 290
(30200), 248 nm (70600 molÀ1 dm3 cmÀ1); MS (ES): m/z calcd for
C86H70N6O8Fe: 685.230 [M/2]; found: 685.229.
nitrile):
lmax
(e)=400
(shoulder),
374
(39450),
247 nm
(132400 molÀ1 dm3 cmÀ1); MS (ES): m/z calcd for C86H74N6O8Co: 459.163
[M/3], 688.744 [M/2]; found: 459.151, 688.721.
[Co(7)2]
a round-bottom flask (25 mL) and dissolved in acetonitrile (12.5 mL). A
solution of Co(NO3)2·6H2O (11.9 mg, 0.041 mmol) in acetonitrile
(12.5 mL) was then added and the reaction was stirred at room tempera-
ture for 30 min. After this time, solution of [NH4]2[Ce(NO3)6]
ACHTUNGTRENNUNG[PF6]3: Compound 7 (56.2 mg, 0.082 mmol) was placed in
ACHTUNGTRENNUNG
a
ACHTUNGTRENNUNG
Acknowledgements
(22.43 mg, 0.0409 mmol) in acetonitrile (22 mL) was added dropwise to
the mixture over a period of 15 min and stirring was continued for
15 min. The organic solvents were evaporated under reduced pressure,
and the solid residue was dissolved in acetonitrile (35 mL). A saturated
aqueous solution of KPF6 (4 mL) was added, the organic solvent was
evaporated and the precipitate was collected by filtration. The acyclic
We are grateful to the CNRS and the Rꢀgion Alsace for fellowships to
J. Lux.
complex [Co(7)2]
1H NMR (CD3CN, 300 MHz): d=8.89 (s, 4H; H4), 8.53 (s, 6H; Hpy1
py2), 7.92 (d, 4H, J=8.1 Hz; H5), 7.78 (t, 4H, J=7.7 Hz; H6), 7.54 (d,
ACHTUNGTRENNUNG[PF6]3 was obtained as an orange solid (112 mg, 73%).
[1] For review articles and books on catenanes and rotaxanes, see refer-
ences [2–9].
[2] G. Schill, Catenanes, Rotaxanes and Knots: Organic Chemistry
,
H
4H, J=7.2 Hz; H7), 7.54 (s, 4H; H1), 6.88 (d, 8H, J=8.6 Hz; Ho), 6.74
(d, 8H, J=8.6 Hz; Hm), 5.93 (ddt, 4H, J=17.2, 10.2, 5.4 Hz; Hc4), 5.30 (d,
4H, J=17.2 Hz; Hc5), 5.12 (d, 4H, J=10.2 Hz; Hc6), 4.21 (m, 8H; Hc1),
4.06 (d, 8H, J=5.4 Hz; Hc3), 3.81 ppm (m, 8H; Hc2); MS (ES): m/z calcd
for C90H78N6O8Co: 476.507 [M/3], 714.760 [M/2]; found: 476.500, 714.757.
MonoACTHNUTRGNEgNUG raphs, Academic Press, New York, 1971, p. 22.
[3] C. O. Dietrich-Buchecker, J.-P. Sauvage, Chem. Rev. 1987, 87, 795–
810.
[4] D. B. Amabilino, J. F. Stoddart, Chem. Rev. 1995, 95, 2725–2828.
[5] F. Vçgtle, T. Dꢃnnwald, T. Schmidt, Acc. Chem. Res. 1996, 29, 451–
460.
[6] Catenanes, Rotaxanes and Knots. A Journey Through the World of
Molecular Topology (Eds.: C. Dietrich-Buchecker, J.-P. Sauvage),
Wiley-VCH, Weinheim, 1999.
[7] M. Fujita, Acc. Chem. Res. 1999, 32, 53–61.
[8] A. Harada, Acc. Chem. Res. 2001, 34, 456–464.
[9] P. D. Beer, M. R. Sambrook, D. Curiel, Chem. Commun. 2006,
2105–2117.
[10] a) C. O. Dietrich-Buchecker, J.-P. Sauvage, J.-P. Kintzinger, Tetrahe-
dron Lett. 1983, 24, 5095–5098; b) C. O. Dietrich-Buchecker, J.-P.
Sauvage, J.-M. Kern, J. Am. Chem. Soc. 1984, 106, 3043–3045;
c) A. M. Albrecht-Gary, Z. Saad, C. O. Dietrich-Buchecker, J.-P.
Sauvage, J. Am. Chem. Soc. 1985, 107, 3205–3209.
[11] a) J.-M. Kern, J.-P. Sauvage, G. Bidan, M. Billon, B. Divisia-Blohorn,
Adv. Mater. 1996, 8, 580–582; b) M. Billon, B. Divisia-Blohorn, J.-
M. Kern, J.-P. Sauvage, J. Mater. Chem. 1997, 7, 1169–1173.
[12] J.-C. Chambron, C. O. Dietrich-Buchecker, J.-P. Sauvage in Compre-
hensive Supramolecular Chemistry, Vol. 9 (Eds.: J. L. Atwood,
J. E. D. Davies, D. D. MacNicol, F. Vçgtle, J.-M. Lehn, J.-P. Sauvage,
M. W. Hosseini), Pergamon, Oxford, 1999, pp. 43–83.
[13] B. Mohr, M. Weck, J.-P. Sauvage, Angew. Chem. 1997, 109, 1365–
1367; Angew. Chem. Int. Ed. Engl. 1997, 36, 1308–1310.
[14] a) G. Rapenne, C. O. Dietrich-Buchecker, J.-P. Sauvage, J. Am.
Chem. Soc. 1999, 121, 994–1001; b) C. O. Dietrich-Buchecker, J.-P.
Sauvage, Chem. Commun. 1999, 615–616.
[15] a) C. Hamann, J. M. Kern, J. P. Sauvage, Dalton Trans. 2003, 3770–
3775; b) C. Hamann, J.-M. Kern, J.-P. Sauvage, Inorg. Chem. 2003,
42, 1877–1883; c) J.-P. Collin, C. Dietrich-Buchecker, C. Hamann,
D. Jouvenot, J.-M. Kern, P. Mobian, J.-P. Sauvage in Comprehensive
Coordination Chemistry II, Vol. 7 (Eds.: J. A. McCleverty, T. J.
Meyer), 2004, pp. 303–326.
[Co(8)]
2,8 mg, 10 mol%) in dichloromethane (1 mL) was added to a solution of
complex [Co(7)2][PF6]3 (62.9 mg, 0.0337 mmol) in degassed dichlorome-
ACHTUNGTRENNUNG[PF6]3: A solution of the catalyst (Grubbs I ruthenium carbene,
ACHTUNGTRENNUNG
thane (40 mL). After 16 h of stirring, more of the catalyst (1.4 mg,
5 mol%) was added to the mixture as the reaction was incomplete. An-
other portion of the catalyst (1.4 mg, 5 mol%) was added to the mixture
after 24 h of stirring for the same reason and the reaction was stirred at
room temperature for another 24 h. The organic solvents were evaporat-
ed and the solid residue was dissolved in acetonitrile (35 mL). A solution
of [NH4]2[CeACHTUNGTRENNUNG(NO3)6] (5.4 mg, 0.0098 mmol) in acetonitrile (12 mL) was
added dropwise to the mixture over a period of 15 min and stirring was
continued for another 15 min. Finally, the solvent was evaporated and
the residue was purified by chromatography on Al2O3 by using dichloro-
methane/acetonitrile (1:1) as the eluent. After evaporation of the collect-
ed fractions, the solid was dissolved in acetonitrile, a saturated aqueous
solution of KPF6 (4 mL) was added, the organic solvent was evaporated
and the precipitate was collected by filtration. The catenane [Co(8)]ACTHNUTRGNEUNG[PF6]3
was obtained as a yellow powder in 70% yield (42.7 mg). 1H NMR
(CD3CN, 300 MHz): d=9.10 (s, 4H; H4), 8.78 (d, 4H, J=8.1 Hz; Hpy1),
8.58 (t, 2H, J=8.1 Hz; Hpy2), 8.13 (d, 4H, J=8.2 Hz; H5), 7.99 (dd, 4H,
J=8.1, 7.2 Hz; H6), 7.73 (d, 4H, J=7.2 Hz; H7), 7.62 (s, 3H; H1), 7.59 (s,
1H; H1), 7.09 (d, 8H, J=8.4 Hz; Ho), 6.96 (d, 8H, J=8.4 Hz; Hm), 6.19
(s, 3H; Hc4cis), 6.06 (s, 1H; Hc4trans), 4.42 (m, 12H; Hc1, Hc3), 4.04 ppm (m,
8H; Hc2); MS (ES): m/z calcd for C86H70N6O8Co: 457.819 [M/3], 686.729
[M/2]; found: 457.818, 686.725.
[Co(9)]ACHTUNGTRENNUNG[PF6]3: Complex [Co(8)]HCATUNGTREN[NUGN PF6] (40 mg, 0.0221 mmol) was dissolved
in a mixture of CH2Cl2 (16 mL) and EtOH (4 mL). The catalyst (Pd/C,
24.6 mg, 0,0221 mmol) was then added and the resulting mixture was
stirred at room temperature for 36 h under an H2 atmosphere. After fil-
tration through Celite, the solvents were evaporated. TLC on alumina
eluted with dichloromethane/acetonitrile (3:2) revealed the presence of
cobalt(II) complexes. The compound was dissolved in acetonitrile
[16] J.-C. Chambron, J.-P. Collin, V. Heitz, D. Jouvenot, J.-M. Kern, P.
Mobian, D. Pomeranc, J.-P. Sauvage, Eur. J. Org. Chem. 2004, 1627–
1638.
(12 mL) and oxidised by addition of a solution of [NH4]2[CeACHTNURGTENUNG(NO3)6]
(4.8 mg, mmol) in a mixture of acetonitrile (10 mL) and dichloromethane
(6 mL) over a period of 15 min. Stirring was continued for a further
15 min. After evaporation of the solvents, the residue was purified by
chromatography on Al2O3 by using dichloromethane/acetonitrile (1:1) as
the eluent. After evaporation of the solvent from the collected fractions,
the solid was dissolved in dichloromethane, a saturated aqueous solution
of KPF6 (4 mL) was added, the organic solvent was evaporated and the
[17] C. O. Dietrich-Buchecker, B. X. Colasson, J.-P. Sauvage, Top. Curr.
Chem. 2005, 249, 261–284.
[18] a) C. Wu, P. R. Lecavalier, Y. X. Shen, H. W. Gibson, Chem. Mater.
1991, 3, 569–572; b) J. D. Megiatto, Jr., D. I. Schuster, Org. Lett.
2011, 13, 1808–1811, and references therein.
[19] a) D. A. Leigh, P. J. Lusby, S. J. Teat, A. J. Wilson, J. K. Y. Wong,
Angew. Chem. 2001, 113, 1586–1591; Angew. Chem. Int. Ed. 2001,
40, 1538–1543; b) D. A. Leigh, P. J. Lusby, R. T. McBurney, A. Mor-
precipitate was collected by filtration. The final catenane [Co(9)]ACHTNUGTRNEG[UN PF6]3
5572
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Chem. Eur. J. 2012, 18, 5565 – 5573

[2]Catenanes
FULL PAPER
elli, A. M. Z. Slawin, A. R. Thomson, D. B. Walker, J. Am. Chem.
Soc. 2009, 131, 3762–3771.
5713; c) T. M. Swager, R. M. Moslin, Synfacts 2007, 1158; d) J.
Bernꢇ, S. M. Goldup, A.-L. Lee, D. A. Leigh, M. D. Symes, G. Teo-
baldi, F. Zerbetto, Angew. Chem. 2008, 120, 4464–4468; Angew.
Chem. Int. Ed. 2008, 47, 4392–4396; e) see also, reference [19c].
[35] Nickel-catalysed homocoupling: S. M. Goldup, D. A. Leigh, R. T.
McBurney, P. R. McGonigal, A. Plant, Chem. Sci. 2010, 1, 383–386.
[36] Nickel–Copper-catalysed homocoupling: J. D. Crowley, S. M.
Goldup, N. D. Gowans, D. A. Leigh, V. E. Ronaldson, A. M. Z.
Slawin, J. Am. Chem. Soc. 2010, 132, 6243–6248.
[20] a) M. Fujita, F. Ibukuro, H. Hagihara, K. Ogura, Nature 1994, 367,
720; b) M. Fujita, M. Aoyagi, F. Ibukuro, K. Ogura, K. Yamaguchi,
J. Am. Chem. Soc. 1998, 120, 611–612.
[21] S. S. Zhu, P. J. Carroll, T. M. Swager, J. Am. Chem. Soc. 1996, 118,
8713–8714.
[22] A. M. Fuller, D. A. Leigh, P. J. Lusby, I. D. H. Oswald, S. Parsons,
D. B. Walker, Angew. Chem. 2004, 116, 4004–4008; Angew. Chem.
Int. Ed. 2004, 43, 3914–3918.
[23] Y. Furusho, T. Matsuyama, T. Takata, T. Moriuchi, T. Hirao, Tetrahe-
dron Lett. 2004, 45, 9593–9597.
[24] a) A. M. L. Fuller, D. A. Leigh, P. J. Lusby, A. M. Z. Slawin, D. B.
Walker, J. Am. Chem. Soc. 2005, 127, 12612–12619; b) S. M.
Goldup, D. A. Leigh, P. J. Lusby, R. T. McBurney, A. M. Z. Slawin,
Angew. Chem. 2008, 120, 7107–7111; Angew. Chem. Int. Ed. 2008,
47, 6999–7003; c) J. E. Beves, B. A. Blight, C. J. Campbell, D. A.
Leigh, R. T. McBurney, Angew. Chem. 2011, 123, 9428–9499;
Angew. Chem. Int. Ed. 2011, 50, 9260–9327.
[25] a) S. J. Cantrill, K. S. Chichak, A. J. Peters, J. F. Stoddart, Acc.
Chem. Res. 2005, 38, 1–9; b) F. Aricꢄ, J. D. Badjic, S. J. Cantrill,
A. H. Flood, K. C.-F. Leung, Y. Liu, J. F. Stoddart, Top. Curr. Chem.
2005, 249, 203–259.
[37] CuI catalysed Diels–Alder: J. D. Crowley, K. D. Hꢆnni, D. A. Leigh,
A. M. Z. Slawin, J. Am. Chem. Soc. 2010, 132, 5309–5314.
[38] a) J. D. Crowley, S. M. Goldup, A. L. Lee, D. A. Leigh, R. T. McBur-
ney, Chem. Soc. Rev. 2009, 38, 1530–1541; b) see also, refer-
ence [24d].
[39] a) F. Durola, J.-P. Sauvage, O. S. Wenger, Chem. Commun. 2006,
171–173; b) F. Durola, L. Russo, J.-P. Sauvage, K. Rissanen, O. S.
Wenger, Chem. Eur. J. 2007, 13, 8749–8753; c) F. Durola, D. Hanss,
P. Roesel, J.-P. Sauvage, O. S. Wenger, Eur. J. Org. Chem. 2007, 125–
135; d) F. Durola, J.-P. Sauvage, O. S. Wenger, Helv. Chim. Acta
2007, 90, 1439–1446.
[40] a) P. Marnot, PhD Thesis, Universitꢀ de Strasbourg (France), 1984;
b) C. O. Dietrich-Buchecker, P. A. Marnot, J.-P. Sauvage, J.-P. Kint-
zinger, P. Maltese, Nouv. J. Chim. 1984, 8, 573–582.
[26] a) J.-P. Sauvage, M. Ward, Inorg. Chem. 1991, 30, 3869–3874; b) N.
Belfrekh, C. Dietrich-Buchecker, J.-P. Sauvage, Inorg. Chem. 2000,
39, 5169–5172.
[27] a) D. Pomeranc, D. Jouvenot, J.-C. Chambron, J.-P. Collin, V. Heitz,
J.-P. Sauvage, Chem. Eur. J. 2003, 9, 4247–4254; b) P. Mobian, J.-M.
Kern, J.-P. Sauvage, J. Am. Chem. Soc. 2003, 125, 2016–2017; c) J.-P.
Collin, D. Jouvenot, M. Koizumi, J.-P. Sauvage, Eur. J. Inorg. Chem.
2005, 1850–1855.
[28] a) A. I. Prikhodꢅko, F. Durola, J.-P. Sauvage, J. Am. Chem. Soc.
2008, 130, 448–449; b) A. I. Prikhodꢅko, J.-P. Sauvage, J. Am. Chem.
Soc. 2009, 131, 6794–6807.
[29] J. C. Loren, P. Gantzel, A. Linden, J. S. Siegel, Org. Biomol. Chem.
2005, 3, 3105–3116.
[30] K. S. Chichak, S. J. Cantrill, A. R. Pease, S.-H. Chiu, G. W. V. Cave,
J. L. Atwood, J. F. Stoddart, Science 2004, 304, 1308–1312.
[31] CuAAC active-metal template: a) V. Aucagne, K. D. Hꢆnni, D. A.
Leigh, P. J. Lusby, D. B. Walker, J. Am. Chem. Soc. 2006, 128, 2186–
2187; b) V. Aucagne, J. Bernꢇ, J. D. Crowley, S. M. Goldup, K. D.
Hꢆnni, D. A. Leigh, P. J. Lusby, V. E. Ronaldson, A. M. Z. Slawin,
A. Viterisi, D. B. Walker, J. Am. Chem. Soc. 2007, 129, 11950–
11963; c) S. M. Goldup, D. A. Leigh, T. Long, P. R. McGonigal,
M. D. Symes, J. Wu, J. Am. Chem. Soc. 2009, 131, 15924–15929;
d) S. M. Goldup, D. A. Leigh, P. R. McGonigal, V. E. Ronaldson,
A. M. Z. Slawin, J. Am. Chem. Soc. 2010, 132, 315–320; e) H. Lahla-
li, K. Jobe, M. Watkinson, S. M. Goldup, Angew. Chem. 2011, 123,
4237–4241; Angew. Chem. Int. Ed. 2011, 50, 4151–4155.
[32] Glaser and Ullman active-metal template: a) S. Saito, E. Takahashi,
K. Nakazono, Org. Lett. 2006, 8, 5133–5136; b) Y. Sato, R. Yamasa-
ki, S. Saito, Angew. Chem. 2009, 121, 512–515; Angew. Chem. Int.
Ed. 2009, 48, 504–507.
[41] J. R. Kirchhoff, D. R. McMillin, P. A. Marnot, J.-P. Sauvage, J. Am.
Chem. Soc. 1985, 107, 1138–1141.
[42] a) P. Schwab, R. H. Grubbs, J. W. Ziller, J. Am. Chem. Soc. 1996,
118, 100–110; b) T. M. Trnka, R. H. Grubbs, Acc. Chem. Res. 2001,
34, 18–29.
[43] V. Goral, M. I. Nelen, A. V. Eliseev, J.-M. Lehn, Proc. Natl. Acad.
Sci. USA 2001, 98, 1347–1352.
[44] J. Chambers, B. Eaves, D. Parker, R. Claxton, P. S. Ray, S. J. Slattery,
Inorg. Chim. Acta 2006, 359, 2400–2406.
[45] A. R. Guadalupe, D. A. Usifer, K. T. Potts, H. C. Humell, A.-E.
Mogstad, H. D. Abruna, J. Am. Chem. Soc. 1988, 110, 3462–3466.
[46] S. H. Wadman, M. Lutz, D. M. Tooke, A. L. Spek, F. Hartl, R. W. A.
Havenith, G. P. M. van Klink, G. van Koten, Inorg. Chem. 2009, 48,
1887–1900.
[47] F. Barigelletti, B. Ventura, J.-P. Collin, R. Kayhanian, P. GaviÇa, J.-P.
Sauvage, Eur. J. Inorg. Chem. 2000, 113–119.
[48] E. C. Constable, G. Baum, E. Bill, R. Dyson, R. van Eldik, D.
Fenske, S. Kaderli, D. Morris, A. Neubrand, M. Neuburger, D. R.
Smith, K. Wieghardt, M. Zehnder, A. D. Zuberbuhler, Chem. Eur. J.
1999, 5, 498–508.
[49] V. Balzani, G. Bergamini, S. Campagna, F. Puntoriero, Top. Curr.
Chem. 2007, 280, 1–36.
[50] B. Ventura, F. Barigelletti, F. Durola, L. Flamigni, J.-P. Sauvage,
O. S. Wenger, Dalton Trans. 2008, 491–498.
[51] P. S. Braterman, J. I. Song, R. D. Peacock, Inorg. Chem. 1992, 31,
555–559.
[52] R. A. Palmer, T. S. Piper, Inorg. Chem. 1966, 5, 864–878.
[53] Kappa CCD Operation Manual, Nonius, Delft, 1997.
[54] SHELXS-97 Program for Crystal Structure Determination: G. M.
Sheldrick, Acta Crystallogr. A 1990, 46, 467–473.
[33] PdII-catalysed Michael addition: S. M. Goldup, D. A. Leigh, P. J.
Lusby, R. T. McBurney, A. M. Z. Slawin, Angew. Chem. 2008, 120,
3429–3432; Angew. Chem. Int. Ed. 2008, 47, 3381–3384.
[34] Heck cross-coupling: a) J. D. Crowley, K. D. Hꢆnni, A.-L. Lee, D. A.
Leigh, J. Am. Chem. Soc. 2007, 129, 12092–12093; b) J. Bernꢇ, J. D.
Crowley, S. M. Goldup, K. D. Hꢆnni, A.-L. Lee, D. A. Leigh, Angew.
Chem. 2007, 119, 5811–5815; Angew. Chem. Int. Ed. 2007, 46, 5709–
[55] G. Sheldrick, SHELXL-97, Universitꢆt Gçttingen, Gçttingen, 1999.
[56] A. L. Spek, J. Appl.Cryst. 2003, 36, 7–13.
[57] M86-E01078 APEX2 User Manual, Bruker AXS Inc., Madison,
2006.
Received: December 28, 2011
Published online: March 19, 2012
Chem. Eur. J. 2012, 18, 5565 – 5573
ꢁ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
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