Control over the Redox Cooperative Mechanism of Radical Carbene Transfer Reactions for the Efficient Active-Metal-Template Synthesis of [2]Rotaxanes

Article abstract of DOI:10.1002/chem.201905602

A 5,15-bis(1,1′-biphenyl)porphyrin-based molecular clip covalently connected to a ditopic aliphatic ester loop moiety yields a semi-rigid macrocycle with a well-defined cavity. The resulting macrocycle fits the structural requirements for the preparation of porphyrinates capable of promoting formation of C?C bonds. To demonstrate the usefulness of porphyrin-based macrocycles, an active-metal-template synthesis of rotaxanes through a redox non-innocent carbene transfer reaction is described. Coordination of Co^II ions into the porphyrin subunit followed by addition of appropriate monodentate nitrogen-based additives to function as axial ligands enables the radical carbene transfer reactions to styrene derivatives to occur exclusively through the cavity of the macrocycle to afford cyclopropane-linked rotaxanes in excellent 95 % yield. Investigation of the product distribution afforded from the rotaxane assembly reaction reveals how the redox cooperative action between the carbene species and the Co^II ions can be manipulated to gain control over the radical-type mechanism to favor the productive rotaxane forming process.

Full text of DOI:10.1002/chem.201905602

A Journal of
Accepted Article
Title: Control over the Redox Cooperative Mechanism of Radical
Carbene Transfer Reactions for the Efficient Active-Metal-
Template Synthesis of [2]Rotaxanes
Authors: Jackson D Megiatto, Arthur F P Alcantara, Liniquer Fontana,
Marlon Almeida, Vitor Rigolin, Marcos Ribeiro, and Wdeson
Barros
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To be cited as: Chem. Eur. J. 10.1002/chem.201905602
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Control over the Redox Cooperative Mechanism of Radical
Carbene Transfer Reactions for the Efficient Active-Metal-
Template Synthesis of [2]Rotaxanes
Arthur F. P. Alcântara[a,b], Liniquer A. Fontana, Marlon P. Almeida, Vitor H. Rigolin, Marcos A.
[a]
[a]
[a]
[
c]
[a]
[a]
Ribeiro, Wdeson P. Barros, and Jackson D. Megiatto, Jr.*
Abstract: A 5,15-bis(1,1’-biphenyl)porphyrin-based molecular clip covalently connected to a ditopic aliphatic ester loop moiety yields a semi-
rigid macrocycle with a well-defined cavity. The resulting macrocycle fits the structural requirements for the preparation of porphyrinates
capable of promoting formation of C–C bonds. To demonstrate the usefulness of porphyrin-based macrocycles, an active metal template
synthesis of rotaxanes through a redox non-innocent carbene transfer reaction is described. Coordination of Co(II) ions into the porphyrin
subunit followed by addition of appropriate monodentate nitrogen-based additives to function as axial ligands enable the radical carbene
transfer reactions to styrene derivatives to occur exclusively through the cavity of the macrocycle to afford cyclopropane-linked rotaxanes in
excellent 95% yield. Investigation of the product distribution afforded from the rotaxane assembly reaction reveals how the redox cooperative
action between the carbene species and the Co(II) ions can be manipulated to gain control over the radical-type mechanism in order to favor
productive rotaxane forming process.
Introduction
The ability of porphyrins to coordinate virtually any metal ion in
its pyrrolic core in conjunction with the possible axial
coordination of monodentate ligands and/or activation of
substrates have been extensively explored in many scientific
components in the interlocked fashion.[12] Furthermore,
introduction of porphyrin ligands yields catalytically active metal
complexes with octahedral and square pyramidal geometries,
which are geometries that are difficult to afford from the usual
bidentate nitrogen-based ligands employed in the AMT protocols.
This diversity in reactivity and complex geometries should widely
expand the scope of the AMT technique, which is currently
based on the Cu(I)-catalyzed 1,3-dipolar cycloadditions (a “click
reaction”), Michael additions, alkyne and alkyl homo- and
heterocouplings, Goldberg C–N bond forming reactions and
oxidative Heck couplings, which are promoted by copper,
palladium and nickel tetrahedral or square planar complexes.[11]
Secondly, the porphyrin pyrrolic core tightly binds the metal ions
at the equatorial (octahedral complexes) or basal (square
pyramidal species) positions of the complex, which prevents
demetallation and subsequent wasteful covalent-bond forming
reactions promoted by free metal ions in the reaction medium
rather than templated by the macrocycle.[13] Thirdly, the
porphyrinate subunit remains active after formation of the
mechanical bond. This means that the turnover of the metal
center in conjunction with the inherent effective molarity
provided by the mechanical bond can be used as principles for
the design of biomimetic molecular machines as alternatives to
the elegant approach explored by the groups of Leigh and
[1]
fields such as models for metalloproteins and enzymes,
catalysis,[2] artificial photosynthesis, host-guest chemistry,[4]
molecular machines,[ photodynamic therapy[6] and metal
organic frameworks.[7] The rich coordination properties and
structural features of porphyrins also abets their application in
metal-template-directed synthesis of interlocked molecules such
as rotaxanes[8] and catenanes.[9] In principle, formation of
mechanical bonds between molecular components composed of
porphyrin subunits can be achieved either by passive- (PMT) or
active-metal-template (AMT) tactics.[10] In the AMT mode, the
metalloporphyrin subunit can substitute the nitrogen-based
binding sites usually positioned on the macrocycle component in
the syntheses of rotaxanes, oligorotaxanes, catenanes and
molecular knots.[11]
[3]
5]
Such substitution provides the AMT approach with many extra
advantages. Firstly, versatile organometallic reactions promoted
by ruthenium, osmium, iridium, rhodium, cobalt, manganese,
and iron ions are at reach and can be explored as synthetic
protocols for the final covalent step that connects the molecular
Nolte.[ Fourthly, concepts of cooperative catalysis, in which
the metal ions and the ligands share redox information during
the catalytic cycle, can be explored with porphyrin-based
macrocyclic ligands to achieve new chemical transformations.
14]
[15]
[
a]
Prof. Arthur F. P. Alcântara, Liniquer A. Fontana, Marlon, P.
Almeida, Vitor H. Rigolin, Prof. Marcos A. Ribeiro, Prof. Wdeson P.
Barros, Prof. Jackson D. Megiatto Jr
Institute of Chemistry, University of Campinas (UNICAMP)
POBox 6154, 13083-970, Campinas, Brazil
E-mail: jdmj@unicamp.br
For example, the groups of de Bruin[
16]
and Zhang
[17]
have
compellingly demonstrated that some metal porphyrinates can
activate organic substrates to produce radical-centered species
that are stabilized by coordination to the axial positions of the
porphyrinate. Such radical-based intermediates present distinct
chemo-selectivity and reactivity than those of their closed-shell
analogues in the subsequent elementary steps of the catalytic
cycle. Finally, the excellent spectroscopic and electrochemical
properties of porphyrinates makes them useful active groups in
[
b]
c]
Prof. Arthur F. P. Alcântara
Instituto Federal do Sertão Pernambucano,
Estrada do Tamboril, 56200-000, Ouricuri, Brazil
Prof. Marcos A. Ribeiro
[
Universidade Federal do Espírito Santo, Departamento de Química
Av. Fernando Ferrari, 514, 29075-910, Vitória, Brazil
Supporting information for this article is given via link at the end of
the document.
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mechanically-linked artificial photosynthetic models, in which the
relative motions of the interlocked components provide useful
information about electron transfer dynamics coupled to
strategies for manipulating the radical mechanism to favor
formation of mechanical bonds rather than unproductive side
reactions.
[
18]
molecular motion.
Scheme 1. General strategy for the synthesis of rotaxanes by AMT
methodology using macrocycles possessing octahedral and square pyramidal
porphyrinate subunits.
Based on those principles, our research group has been
interested in porphyrin-based macrocycles as endotopic
catalysts in the syntheses of rotaxanes and polyrotaxanes by
AMT. Our general strategy is schematically represented in
Scheme 1. For metalation of the porphyrin-based macrocycle
with metal ions and/or oxidation states that preferentially form
hexacoordinated species in an octahedral geometry, the
synthesis involves formation of the octahedral porphyrinate with
two weakly bound axial ligands (LIN and LOUT) that can be easily
displaced by strong and kinetically robust ligands. However, the
central cavity of the porphyrin-based macrocycle has a specific
size, which discourages coordination of bulky ligands (LBULKY
)
inside the hollow macrocyclic structure due to steric hindrance,
hence creating an asymmetry in the reactivity of the two axial
coordinating sites of the octahedral porphyrinate. Therefore,
L
BULKY selectively displaces the LOUT ligand to produce the oh
Results and Discussion
endotopic catalyst. The strong kinetic trans effect caused by the
thermodynamically stable and kinetically inert LBULKY induces
dissociation of LIN, thereby leaving the internal coordination site
free for activation of non-bulky substrates to trigger
organometallic reactions. Thus, combination of the inherent
structural constraints of the macrocyclic porphyrinate and the
electronic effects caused by axial coordination of LBULKY enable
the covalent reactions to occur exclusively inside the cavity; the
essential pre-requisite for efficient mechanical bond formation by
the AMT technique.
The design of the porphyrin-based macrocycle must comply with
some molecular structural requirements for the successful
exploration of the strategy depicted in Scheme 1. Firstly, the
macrocycle must be chemically inert to the highly reactive
transient species generated during the organometallic cycle.
Secondly, the dimensions of the central cavity must be well-
defined for the fruitful exploration of the steric bias by axial
coordination and selective internal substrate activation. To
satisfy those requirements, attachment of relatively inert ortho-
substituted biphenyl moieties to the 5,15-meso positions of the
porphyrin core creates a porphyrin-based molecular clip, which
defines the cavity width after the macrocyclization reaction.
Macrocyclization of the functional groups at the ends of the
biphenyl moieties on the porphyrin molecular clip with ditopic
and stiff molecular linker should yield a hollow receptor with a
well-defined central cavity. However, some conformational
flexibility of the molecular loop might be necessary for catalytic
activity as axial coordination of bulky monodentate ligands might
promote severe distortions of the porphyrin group if the hollow
receptor is too rigid. Distortions can lead to changes in reactivity
or even inactive porphyrinates.[20] Furthermore, the planarity of
the porphyrin core is required for our purposes as deformations
of the tetrapyrrolic core can expose the internal axial binding site
to the bulky ligand, thereby reducing the steric shielding
provided by the appended loop with consequent shattering of
the structural bias of the macrocyclic receptor. Accordingly,
semi-rigid macrocycles seem to be ideal candidates in our
studies instead of rigid ones.
The strategy is trivially adapted for pentacoordinated
porphyrinates in a square pyramidal geometry, which have
already worked well for the AMT synthesis of [2]rotaxanes. In a
preliminary communication,[19] we demonstrated that
a
Co(II)porphyrinate-based macrocycle with an external bulky
pyridine axial ligand functions as a square pyramidal endotopic
and redox non-innocent catalyst to promote radical carbene
transfer reactions between functionalized diazo and styrene half-
thread substrates. Under optimized conditions, cyclopropane-
linked [2]rotaxanes was afforded in excellent 95% yield. As far
as we know, our previous communication pioneers the
exploration of cooperative catalysis concepts and radical
carbene chemistry on the syntheses of mechanically-linked
systems.
Herein, we give a full description of our investigation, which
reveals the critical molecular structural parameters necessary for
Co(II)porphyrinate-based macrocycles to successfully promote
cyclopropanation reactions in an endotopic fashion in the
presence of monodentate nitrogen-based axial ligands.
Furthermore,
a detailed study about the cyclopropanation
The synthetic strategy to prepare the semi-rigid macrocycle is
based on the preformation of the 5,15-biphenyl-porphyrin clip,
which bears phenol groups for the double esterification
macrocyclization reaction with flexible aliphatic dicarboxylic acid
linkers in the final synthetic step (Scheme 2). The synthesis of
the macrocycle begins with a classical Suzuki reaction between
reaction conditions is reported, which demonstrates the effects
of concentration, solvent, bulkiness of the external axial ligand
and reagent stoichiometry in the outcome of the [2]rotaxane
forming reaction. Such detailed investigation provides
compelling evidence for the critical structural parameters
necessary for the successful endotopic cyclopropanation
reaction promoted by macrocyclic Co(II)porphyrinates as well as
commercially available compounds
1
and
2
to afford
intermediate in 90% yield, which is condensed with
3
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dipyrromethane under Lindsey’s conditions[21] to yield
atropisomers 4 and 5. The atropisomers are separated in two
steps. Firstly, the crude product is passed through a column
that those protons are close to the porphyrin core and
experience the shielding effects promoted by the porphyrin
aromatic ring current. On the other hand, the CH groups on the
2
chromatography on regular silica (SiO
hexane/ethyl acetate (4:1, v/v) as eluent to afford the two
atropisomers as a mixture in 37% yield. A second column
2
) using a mixture of
aliphatic chain linker (HI-L) appear in the expected region of the
spectrum and fell none of the porphyrin magnetic anisotropy.
The N–H resonance is a proxy for the porphyrin core planarity
chromatography on previously Et
dichloromethane/acetone (94:6, v/v) as eluent allows separation
3
N-neutralized SiO
2
using
status in solution. It is known that distortions of the porphyrin
core deshield the N–H nuclei.[
20]
For example, the N–H
of atropisomers 4 and 5 in 16% and 21% yields, respectively.
resonance of the nonplanar 5,15-di(tert-butyl)porphyrin
compound was seen at  = –0.95 ppm,[20e] while the severely
For the macrocyclization step, atropisomer
4 is useless.
However, 4 can be thermally converted into target atropisomer 5
upon heating in DMF for 12 h in 70% yield. This atropisomer
thermal interconversion is performed twice, therefore the total
yield of 5 increases from 21% to 35%.
distorted tetra-substituted analog gave N–H signal at  = +1.58
ppm.[
20f]
The N–H nuclei in 6 resonates as a slightly broad
singlet at  = –3.22 ppm.[22] The N–H signal in flat porphyrin
model compound S1 (Figure S1, S.I.) appears as a singlet at  =
–3.10 (Figure S2 in S.I.) under the same conditions. Those
Scheme 2. Synthetic strategy for the preparation of semi-rigid macrocycles.
findings, in conjunction with the sharpness of the signals in the
H NMR spectrum of 6 are consistent with a flat porphyrin
1
subunit.
The UV-Vis ground-state absorption spectrum of
6
in
dichloromethane solution (Figure S3, S.I.) exhibits the
characteristic electronic transitions of flat porphyrins, featuring
the Soret and Q-absorptions at λmax = 411 and 506, 539, 579
and 634 nm, respectively. Virtually identical values are afforded
for those diagnostic absorptions (Figure S4, S.I.) for flat
porphyrin S1 (409 nm (Soret) and 504, 538, 578, 631 nm (Q-
bands)). The typical large red-shifts observed for the *
electronic transitions of nonplanar porphyrins[ are not found in
the absorption spectrum of 7, thereby confirming the flatness of
its porphyrin subunit in solution.
20]
3 2 2
Metalation reaction of macrocycle 6 using Co(CH COO) •4H O
in DMF at reflux and under inert atmosphere for 2 hours yields
Co(II)porphyrinate-based macrocycle 7 (Scheme 3) in 78%
isolated yield. MALDI-TOF mass spectrometry shows a single
+
m/z signal at 854.75 [M] (Figure S5, S. I.), which corresponds to
For the final double esterification macrocyclization reaction of 5,
we used azelaic acid as the molecular linker, N,N’-
dicyclohexylcarbodiimide (DCC) as coupling agent and 4-
dimethylaminopyridine (DMAP) as catalyst. Under those
conditions, macrocycle 6 was afforded in 37% yield. The crystal
structure of the Co(II)porphyrinate prepared from macrocycle 6
and reported in our previous communication[19] (CCDC 1823132)
confirms that the ester aliphatic linker obtained from the
condensation of azelaic acid and porphyrin 5 has the right length
as no significant distortion of the tetrapyrrolic core was observed
in the solid state.
the molecular ion mass of
7
(855.24, calculated for
53 40 4 4
C H N O
Co). UV-Vis absorption spectroscopy (Figure 2)
confirms the Co(II)porphyrinate oxidation state in 7 by showing
the characteristic Soret (λmax = 404 nm) and broad Q-bands (λmax
520 and 551 nm).[23]
=
With macrocycle 7 in hands, we turned our attention to the
synthesis of target rotaxane 14, using diazo and styrene half-
threads 8 and 9 as substrates (Scheme 3). Several factors
(
concentration, solvent effects, type and bulkiness of the
external axial ligand and reagent stoichiometry) influencing the
outcome of the [2]rotaxane assembly reaction were investigated.
The several experimental conditions explored to optimize the
rotaxane yield are summarized in Table 1. Concentration is key
for the successful radical carbene transfer reaction as side
The 1H NMR spectrum of
resonances of the meso (H ) and pyrrolic (H
6
(Figure 1, top) shows the
) nuclei as well as
A
B
those in the phenyl rings (HC-E) attached to the 5,15 positions of
the porphyrin core in the expected region of the spectrum and
with the correct multiplicity. Protons at the phenolic ester ring
reactions with solvent molecules might compete for the
carbenoid intermediate.[16,17,24]
H G G
(H and H ) are somewhat shielded, particularly H , informing
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B
A
B
*
H
G
L
E,D
K
C
F
I,J
NHINNER
/
/
P,Q
P
TMS
B,B
H,T
G
*
*
E,D
F
A
Q’
R
*
L
K **I,J
M
O
N
C
S
R’
/
NHIM
U
*
*
V
W
X*
/
P,Q’,U
S
**
TMS
Q
R’
T
R
**
V
W X*X*
/
/
Figure 1. 1H NMR spectra (400 MHz, CDCl
NMR. The two nuclei on the cyclopropane moieties are labelled H * on thread 15 and rotaxane 24 as they are diastereotopic and resonate at different chemical
, 298 K) of macrocycle 6 (top), rotaxane 24 (middle) and thread 15 (bottom). Proton assignments were based on 2D-
3
[
19]
X
shifts. TMS = tetramethylsilane, *residual chloroform ( = 7.26 ppm), dichloromethane ( = 5.29 ppm) and water ( = 1.56 ppm). ** = aliphatic impurities.
Table 1. Experiments to determine the optimal conditions for the synthesis of rotaxane 14 through the radical carbene transfer cyclopropanation reaction as a
metal-active-template methodology.[a]
Yield (%)[b]
ratio[d]
7:8:9
1:1:1
1:1:1
1:1:1
1:1:1
1:1:1
1:1:1
1:1.2:5
thread
complex
12+13[f]
rotaxane
14[f]
45
rotaxane
macrocycle 7
15[e]
12
22
25
20
-
byproduct[f]
Entry
Additive
-
1
30
3
4
4
3
3
3
3
20
29
24
26
10
6
2
imidazole
39
23
3
pyridine
36
30
4
4-t-butylpyridine
3,5-diphenylpyridine
3,5-diphenylpyridine
3,5-diphenylpyridine
35
32
5
25
62
6[c]
7[c]
-
17
72
-
-
95
-
[
a] Reactions carried out at 0.053 M concentration with respect to macrocycle 7 in toluene, under inert atmosphere for 18 h total reaction time at room
temperature. In all experiments, total consumption of half-thread 8 was observed.
[
[
[
[
[
b] Yields of isolated products. To achieve the reported yields, the purification process of the crude products must be carried out under inert atmosphere.
c] Slow addition of half-thread 8 (0.2 equiv with respect to 1 every 2 h).
d] molar ratio.
e] relative to 8.
f] relative to 7.
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As a control experiment, we performed the reaction with no
addition of axial ligands and with an equimolar mixture of 7, 8
and 9 in toluene at 0.053 M concentration level (entry 1, Table
1). It should be noted that the purification process of the
resulting crude reaction mixture must be carried out under inert
atmosphere to achieve the isolated yields reported in Table 1.
We have found that performing the purification step under
regular atmosphere leads to partial oxidation of the
Co(II)porphyrinate-based products by molecular oxygen. This
oxidation reaction yields a complex porphyrin mixture and
renders the purification process of the products difficult.
Careful separation of the crude mixture revealed formation of
rotaxanes 14 in 45% yield and complexes 12 and 13, which
were separated as a mixture in 30% total yield, as well as
noninterlocked thread 15 and macrocycle 7 in 12% and 20%
yields, respectively. Furthermore, a rotaxane byproduct is also
isolated in 3% low yield from the reaction mixture. The
conceivable reaction pathways[16,17,24] for formation of the
isolated products afforded from the control experiment of the
rotaxane assembly reaction are depicted in Scheme 3.
Formation of rotaxane 14 and thread 15 in a molar ratio ~ 4:1 is
surprising as the reactants should have had easier access to the
exo coordination site of the Co(II)porphyrinate in 7 during the
cyclopropanation reaction. This finding informs that the radical
carbene transfer reaction preferably occurs inside the
macrocyclic cavity (steps a and b, Scheme 3) rather than the
expected exo fashion (steps c and d). We rationalize this
endotopic selectivity in terms of the high concentration level of
the macrocycle 7 and half-thread 9 in the experiment, which
might favor the reversible coordination of the olefin group
Figure 2. Ground state UV-Vis absorption spectra of macrocycle 7.
Conditions: DCM solution at 10-5 M concentration, 298 K.
Scheme 3. Proposed reaction pathways for formation of the products isolated
from the rotaxane assembly process with no addition of nitrogen-based
ligands (control experiment).
present in
9
to the external axial position of the
Co(II)porphyrinate subunit in 7 (Scheme 4). If such plausible
interaction occurs,[24] activation of diazo half-thread 8 exo to the
macrocyclic cavity to yield 11 (step c, Scheme 3) is kinetically
disfavored, thereby forcing the organometallic cycle to
preferentially take place endo to the macrocyclic cavity.
UV-Vis titration experiment in toluene and under N
confirms the axial intermolecular interaction between macrocycle
and half-thread 9 (Figure S6). By increasing the concentration
of half-thread 9, the intensity of the Soret band of 7 with λmax at
09 nm decreases while the second absorption in the Soret
2
atmosphere
7
4
region with λmax at 430 nm, which is due to the axial interaction
between the Co(II) ion and half-thread 9,[23] increases. The
evolution of the Soret bands upon titration of 7 with 9 supports
the argument that intermolecular interactions between those
reactants partially block the external axial coordination site of the
Co(II)porphyrinate subunit of 7 to favor the organometallic
reactions to occur in an endotopic fashion during the rotaxane
assembly process at the high concentration levels studied.
Identification of complexes 12/13 in the mixture informs that
collateral radical hydrogen abstraction reactions also occur
during the rotaxane self-assembly reaction (steps e and f,
Scheme 3).[16,17,24] Although in very low isolated yield,
observation of a rotaxane byproduct (step g, Scheme 3) in the
reaction mixture is interesting. The MALDI-TOF mass spectrum
Therefore,
the
proposed
radical
carbene
transfer
cyclopropanation reaction is kinetically favored under the highest
concentrations possible of 7, 8 and 9. Solubility tests with the
components of the target [2]rotaxane 14 reveal that toluene and
dichloromethane allow the highest concentration levels to be
achieved (0.053 M). Toluene turned out to be the best solvent as
dichloromethane gives precipitates along with an intricate
porphyrinate product mixture, presumably due to side reactions
between the reactants with the halogenated solvent during the
rotaxane assembly reaction.
(
Figure S7) of this rotaxane byproduct reveals a m/z peak at
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Scheme 4. Intermolecular interaction between macrocycle 7 and half-thread 9
that favour the organometallic reactions to occur in an endotopic fashion
during the rotaxane assembly process at the high concentration levels studied.
endo to the macrocyclic cavity of the ring component of rotaxane
14 (step a, Figure S8) to produce carbenoid species 16.
Complex 16 further abstracts a radical hydrogen atom from the
C–H bonds of the cyclopropane moiety or those at the benzylic
position on the thread component (step g, Figure S8). If such
intercomponent reaction occurs, transient species such as
Co(III)porphyrinate-based rotaxane 20, whose radical center
resides on the thread component is produced. Further homolytic
cleavage of the C–Co(III) bond followed by radical
recombination with the thread (step h, Figure S8) affords the
insertion of the carbenoid fragment into the C–H bonds of the
thread to yield Co(II)porphyrinate-based rotaxanes such as 21.
Rotaxane 21 is just one example of the possible interlocked
structure afforded from the intercomponent C–H insertion
reactions. The green C–H bonds in 16 (Figure S8) are the
potential reactive sites on the thread for carbenoid
insertions.[16,17,24] Accordingly, the rotaxane byproduct isolated in
our investigation is most likely a mixture of isomeric rotaxanes
originated from insertions of the carbenoid fragment into those
C–H bonds highlighted in green in Figure S8. Such C–H
insertion reaction pathways for radical carbenoids species have
been recently reported in the literature.[25] In our case, the
mechanical bond in rotaxane 14 constantly keeps the thread
component in close contact with the Co(II) active center, hence
creating a significant molarity effect[8h,14c] that facilitates the
follow up intercomponent C–H insertions with additional 8.
2
059.72 along with that for rotaxane 14 and its characteristic
stepwise fragmentation pattern.[19] The m/z 2059.72 corresponds
to a molecular ion composed of rotaxane 14 linked to an
additional half-thread 8 minus a N
2
molecule. This finding
suggests that the Co(II)porphyrinate subunit in rotaxane 14 is
still active and can react with an extra half-thread 8 to yield
carbenoid species inside or outside the macrocyclic cavity (steps
a and b, Figure S8).
In principle, the carbenoid species 16 and 17 have two possible
fates; undergo cyclopropanation or hydrogen abstraction
reactions.[16,17,24] If formation of the carbenoid intermediate takes
place inside the cavity, cyclopropanation reactions between 16
and 9 should have yielded [3]rotaxanes (step c, Figure S8),
which would be composed of a ring component trapped by two
molecular threads. Such [3]rotaxanes is never observed by
MALDI-TOF mass spectrometry or TLC technique in our
experiments. Therefore, step c in Figure S8 is ruled out.
Congruently, if formation of the carbenoid species occurs
outside the cavity of 14 (step b, Figure S8), cyclopropanation
with 9 yields thread 15 while regenerating rotaxane 14 (step d,
Figure S8), and no such rotaxane byproduct should have been
observed in our experiments.
Figure 3 – Ground state UV-Vis absorption spectrum of Co(II)-containing
rotaxane 14 (green line), rotaxane byproduct (orange line) and Co(III)-
containing byproduct mixture 12 + 13 (purple line).
Hydrogen abstraction reactions are not the reaction pathway to
the rotaxane byproduct either. Hydrogen abstractions by
carbenoid intermediates 16 and 17 should provide alkyl
Co(III)porphyrinate-based rotaxanes 18 and 19, respectively
With identification of the products afforded from the rotaxane
self-assembly reaction, we investigated the axial coordination
properties of macrocycle 7. We selected nitrogen-based ligands
as they are excellent ligands to form kinetically robust
(
steps
spectroscopy (Figure 3) clearly reveals that the isolated rotaxane
byproduct bears
Co(II)porphyrinate subunit,[23] thereby
e and f, Figure S8). However, UV-Vis absorption
[26]
a
pentacoordinate Co(II)porphyrinates. Performing the rotaxane
confirming that the half-thread fragment produced from diazo
derivative 8 is not linked to the rotaxane structure through the
Co(II)porphyrinate moiety.
Based on those data, we have speculated that this rotaxane
byproduct is most likely formed by coordination of semi-thread 8
reaction using an equimolar mixture of 7, 8 and 9 in toluene at
0.053 M concentration level but in the presence of 1.0 equivalent
of imidazole as axial ligand (entry 2, Table 1) reduces the yield
of rotaxane 14 in half (from 45% to 23%), while improving the
yield of thread 15 (from 12% to 22%). Similar results were
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afforded from the experiments using pyridine (entry 3, Table 1)
and 4-tert-butylpyridine (entry 4, Table 1) as axial ligands. Those
reaction outcomes are in sharp contrast with what one expects
and demonstrate that addition of axial ligands renders the
rotaxane forming reaction rather difficult, while favoring the
sixth coordination and the lack of bulkiness of the imidazole
ligand regarding the size of the cavity in macrocycle 7.
Performing the same oxidation reaction in the presence of 4-t-
butylpyridine results in complex 23, whose 1H NMR spectrum
(Figure 5) clearly shows two sets of signals for the pyridine
M N O
nonproductive exo reaction that affords noninterlocked thread 15. nuclei H , H and H , again indicating coordination of two
Puzzled by the data, we decided to study whether the pyridine
and imidazole derivatives were not bulky enough to prevent
coordination to the internal axial position of the Co(II) ions in
macrocycle 7. As Co(II)porphyrinates are paramagnetic species
and preferentially form pentacoordinate complexes with nitrogen
based ligands, it proved convenient to oxidize the Co(II) ions in 7
to the diamagnetic Co(III)porphyrinate analog, whose molecular
structure could be investigated by NMR spectroscopy.
Furthermore, it is well-established that Co(III) ions exclusively
yield hexacoordinate species in the presence of nitrogen-based
ligands.[27] Therefore, the large driving force for the binding of
the sixth ligand in the coordination sphere of the
Co(III)porphyrinate in oxidized 7 might cause severe distortions
of the macrocyclic structure and would allow us to test to the
limit the steric shielding enforced by the central cavity of
macrocycle 7 on the internal axial coordination site.
pyridine axial ligands to the Co(III)porphyrinate to yield a
hexacoordinated complex with a distorted geometry.
O
*
*
H
G
B
D,E,F
C
M
A
N
K
*
I
L
*
J
*
*
Figure 5. Molecular structure and 1H NMR spectrum of complex 23 (250 MHz,
CDCl , 298 K). * residual chloroform ( = 7.26 ppm), dichloromethane ( =
4
Treating 7 with AgBF as oxidizing agent in a dichloromethane
solution in the presence of 2.20 equivalents of imidazole,
followed by filtration and recrystallization of the crude from
3
5.29 ppm), diethyl ether ( = 3.48, and 1.21 ppm) and water ( = 1.60 ppm).
DCM/diethyl ether, quantitatively yields complex 22 (Figure 4).
1
This complex gives a sharp H NMR spectrum in CDCl
4
3
(Figure
The molecular structure of complex 23 is confirmed by x-ray
diffraction on single crystals grown from slow vapor diffusion of
diethyl ether to a saturated solution of 23 in dichloromethane
(Figure 6a). The solid state structure of 23 consists of
crystallographic independent Co(III)porphyrinate units arranged
in the C2/c space group of the monoclinic system and containing
BF4– anions to ensure charge neutrality. The Co–Naxial bond
distances on the complex are virtually the same (1.974(4) and
1.976(4) Å) with the Co(III) ion only displaced 0.0085(12) Å from
the porphyrin mean plane toward the cavity, which informs that
the two axial ligands exert similar trans influence to each other.
Conversely, the Co–Nequatorial distances are not equal (ranging
from 1.960(4) to 1.976(4) Å), while the Naxial–Co–Naxial angle
), thus confirming that the structure contains diamagnetic
Co(III) ion rather than the paramagnetic Co(II) analog. Axial
coordination of the imidazole ligands is clearly confirmed by the
M N O
large shielding observed for protons H , H e H , as they
experience the strong ring current effect of the porphyrin
aromatic system. Furthermore, the signals for the imidazole
nuclei appear in duplicate, thereby revealing that the imidazole
moieties feel distinct magnetic anisotropy from the porphyrin
core.
(
178.2) and Naxial–Co–Nequatorial angles (ranging from 86.89(16)°
to 92.19(16)°) somewhat deviate from those of the idealized
octahedral symmetry point group (180° and 90° angles,
*
respectively). Those structural parameters inform
a non-
negligible distortion of the porphyrin moiety in 23. Congruently,
the z-coordinate displacements for each atom (h, in Å, Figure
6b) from the porphyrin mean plane (root-mean-square out-of-
plane value of 0.25 Å) indicate a distortion pattern typical of a
saddled conformation combined with a small degree of ruffled
conformation.[ The mean plane of the inner axial ligand is
oriented parallel to the Co–Cmeso axis, making a negligible 0.74°
angle, while the outer ligand counterpart yields a 17.07° angle
with the corresponding Co–Cmeso axis (red lines in Figure 6c).
Accordingly, the dihedral angle between the two mean planes of
the axial ligands is 73.60(22)°. In planar porphyrinates axially
coordinate to pyridine ligands, this dihedral angle is usually
about 90° as the axial ligands orient themselves perpendicular to
each other and in a staggered conformation about the Co–
*
*
B
A
H
G
D
L
K
E,F
C
M
O
I
**
M
N
*
*J
N
NH
20]
Figure 4. Molecular structure and 1H NMR spectrum of complex 22 (250 MHz,
CDCl , 298 K). * residual chloroform ( = 7.26 ppm), acetonitrile ( = 2.07
3
ppm) and water ( = 1.56 ppm). ** = aliphatic impurities.
Two set of signals confirm formation of the hexacoordinated
complex and inform that complex 22 adopts
geometry. Those findings provide unequivocal evidence for the
a distorted
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a)
b)
d)
c)
Figure 6. a) Crystal structure of complex 23. Carbon atoms are shown in gray, nitrogen in light blue, cobalt in dark blue, oxygen in red, boron in light pink and
fluorine in green. Hydrogen atoms are omitted for clarity purposes. Ellipsoids are drawn at 50% probability levels (CCDC deposit number 1971223). b) cylindrical
projection of the porphyrin moiety of 23 with the z-coordinate displacement relative to the porphyrin mean plane on the vertical axis (h, in Å), and the azimuthal
angle on the horizontal axis. The inset scheme shows the porphyrin core conformation with open-orange circles and closed-blue circles representing atoms lying
above and below the mean plane, respectively. c) Top view of the crystal structure of 23 highlighting the orientation of the 4-t-butylpyridine axial ligands about the
porphyrin core. d) View of the crystal structure of 23 highlighting the tilt angles of the axial ligands.
N
equatorial bonds (i.e. producing a 45° angle with the Co–Nequatorial
(Figure 6d). The outer ligand makes an 87.57(22)° angle, which
is much closer to the 90° value expected for a perfect axial
coordination than that of 84.97(15)° observed for the inner
analog. The smaller tilt angle of the inner ligand is due to the
steric interactions between the t-butyl groups on the inner axial
ligand and the aliphatic molecular loop appended on the
porphyrin macrocycle. Furthermore, this steric clash forces the
macrocycle ligand in complex 23 to adopt a folded conformation
with the aliphatic ester loop partially blocking one of the faces of
the macrocyclic receptor, therefore leading to the relative
disorder of the aliphatic loop atoms observed in the crystal
structure of 23 and the collapse of the well-defined cavity
bond axis) to prevent steric interactions between the hydrogen
atom at the 2 and 6 positions of the pyridine moieties and the
pyrrolic nitrogen atoms of the porphyrin group.[20,26] In the case
of 23, the smaller dihedral angle observed between the axial
ligand reflects the necessity of the system to accommodate both
axial ligands in the Co(III) ion coordination sphere in a such way
as to minimize steric clashes between the pyridine axial
hydrogen atoms and the nonplanar conformation of the
porphyrin group.
Another interesting feature of the solid-state structure of 23 is
the tilt angle of the axial ligands about the porphyrin mean plane
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originally observed in 7.[19] The crystal data is in complete
agreement with the H NMR spectrum afforded for 23 (Figure 5),
abstraction reactions that affords complexes 12 and 13, an
excess of styrene half-thread 9 is necessary. Furthermore, a
slight excess of diazo half-thread 8 is also needed to warrant
total interlocked of macrocycle 7. Accordingly, running the
reaction in the presence of 5.0 equiv. of styrene half-thread 9
with slow addition (0.20 equiv. every 2 h) of 1.2 equiv. of the
diazo counterpart 8 (entry 7, Table 1) results in an impressive
95% rotaxane isolated yield with total interlocking of macrocycle
8 and no signs of formation of any of the byproducts isolated in
the control experiment, except for the rotaxane byproduct. The
rotaxane byproduct yield is independent of the concentration of
half-threads 8 and 9 as well as the presence of axial ligands, a
finding that nicely corroborates our hypothesis that this rotaxane
byproduct results from intercomponent reactions.
1
thus confirming that the structural features observed in the solid-
state is also present in solution; i.e. the two 4-t-butylpyridine
axial ligands are not magnetically equivalent as they experience
distinct chemical environments. Our investigation clearly reveals
that the internal axial coordination of the chosen nitrogen-based
ligands is a likely event occurring during the rotaxane assembly
reaction and should be the main cause for the reduced rotaxane
yields observed in the experiments with axial ligands when
compared to the control one. This internal coordination also
explains the higher yields afforded for thread 15. Therefore, we
decided to use bulkier 3,5-diphenylpyridine as axial ligand in the
next experiments.
Performing the rotaxane assembly reaction under standard
conditions in the presence of 1 equiv. of 3,5-diphenylpyridine
The UV-Vis investigation (Figure 7) on the rotaxane isolated
from the experiment with addition of 3,5-diphenylpyridine reveals
a spectrum identical to that of rotaxane 14; i.e. Soret band at
(
entry 5, Table 1) improves the rotaxane yield from 45% to 62%,
while precluding the formation of thread 15. This important
finding reveals that no cyclopropanation reaction is taking place
external to the macrocycle’s cavity. Congruently, the 3,5-
diphenylpyridine species must selectively coordinate to the
Co(II) ion at the uncapped axial position of the porphyrin face
during the rotaxane assembly reaction.
Having established that 3,5-diphenylpyridine additive enables
macrocycle 7 to become an endotopic mediator for the radical
carbene transfer reactions, we turned our attention to the
reactant stoichiometry, which proved to be extremely important
for the rotaxane yield. From the product distribution of the control
experiment (Scheme 3), the endotopic carbenoid species
forming from the reaction between macrocycle 7 and diazo half-
thread 8 in the presence of the bulky axial ligand has four
possible fates: 1) addition to the olefin to afford the
cyclopropane-linked rotaxane 14; 2) promotion of deleterious
radical hydrogen abstraction reactions to yield inactive alkyl-
Co(III)-complexes such as 12 and 13; 3) intercomponent C–H
insertion reactions to afford the rotaxane byproduct and 4) side
reactions with toluene solvent molecules.
max = 407 nm and a broad Q-band at max = 525 nm, which are
the usual electronic transitions observed for Co(II)porphyrinates
with no axial ligands.[
23,26]
On the other hand, a solution of
rotaxane 14 in the presence of 1 equiv. of 3,5-diphenylpyridine
shows the Soret band at max = 407 nm along with an extra
absorption at max = 426 nm, which indicates formation of the
pentacoordinate Co(II)porphyrinate species.[
26]
Therefore, one
can conclude that the pentacoordinate Co(II)porphyrinate
species is formed during the rotaxane assembling reaction
(Scheme 5), which explains the excellent rotaxane yield
observed, but the axial ligand is lost during the purification
process, probably on the column chromatographic step using
regular silica.
Diazo derivatives are potential radical hydrogen sources in
metal-catalyzed carbene transfer reactions.[16n,28] Therefore,
reduction of the concentration of half-thread 8 in the reaction
medium should kinetically disfavor the unproductive radical
hydrogen abstractions that lead to 12 and 13. Performing the
stoichiometric rotaxane assembly reaction (entry 6, Table 1) but
with portion-wise addition of 8 (0.20 equiv. every 2h) reduces
formation of alkyl-Co(III) complexes from 30% to 17%.
Accordingly, diazo half-thread 8 is an important radical hydrogen
source for the carbenoid species in our experiments. Radical
hydrogen abstractions from diazo derivatives have been
observed in reactions between ethyl diazoacetate and
Rh(II)porphyrinates[28a] as well as in Ir(II)-radical carbenoid
complexes.[28c]
Figure 7. Ground state UV-Vis absorption spectra of pristine rotaxane 14
(green line) and rotaxane 14 in the presence of 1 equiv. of 3,5-
diphenylpyridine (pink line). Conditions: DCM, room temperature and 10-5
Recover of macrocycle 7 in 6% yield from the crude advises that
side reactions, probably with toluene solvent molecules,[24] are
mol/L concentration.
still consuming half-thread
8
in unproductive process.
To investigate the structure of rotaxane 14 by NMR
spectroscopy, we used AgBF as oxidizing agent to convert the
4
paramagnetic Co(II)porphyrinate-based rotaxane 14 into the
diamagnetic Co(III)porphyrinate-based analog. However,
Congruently, it seems logic that to kinetically favor the
cyclopropanation process over the deleterious side reactions
with solvent molecules as well as unproductive radical hydrogen
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1
Scheme 5. Proposed mechanism for formation of rotaxane 14 from half-
threads 8 and 9 and macrocycle 7 in the presence of 3,5-diphenylpyridine
axial ligand. The penta-coordinated species is formed during the rotaxane
assembly reaction, but the axial ligand is lost during the purification process
complex H NMR spectra are afforded for the oxidized rotaxanes
even when running the oxidation reaction in neat coordinating
solvents, such as DMSO, CH
3
CN and THF. The complexity of
1
the H NMR spectra of the oxidized rotaxane could come from
movements of the ring component about the thread, which
would indicate that the oxidized rotaxane adopts several co-
conformations in solution. However, variable temperature NMR
experiments indicate no coalescence of the intricate 1H NMR
spectra afforded for the oxidized rotaxane, hence ruling out the
possibility of relative intercomponent motions. An alternative
(step a). Subsequent oxidation reaction of 14 in the presence of imidazole as
axial ligand affords diamagnetic rotaxane 24 (step b), which is suitable for
structural investigation by NMR spectroscopy. The two nuclei on the
X
cyclopropane moiety in 24 are labelled H * as they are diastereotopic and
resonate at different chemical shifts.
1
explanation for the complexity of the H NMR spectrum is slow
exchanging of the weak and kinetic labile axial solvent ligands,
which might yield rotaxanes possessing several distinct
Co(III)porphyrinates subunits, therefore accounting for the
complexity of the NMR spectra afforded for the oxidized
interlocked structures. Gratefully, performing the oxidizing
reaction on rotaxane 14 in the presence of 1.5 equiv of
III
kinetically robust nitrogen-based ligands affords Co -based
1
rotaxanes, which yield clean H NMR spectra. Accordingly, slow
exchange of the solvent axial ligand is probably the source of
complexity in our NMR investigation on the oxidized rotaxanes.
We chose imidazole as the axial ligand for the NMR
investigation of our rotaxanes (Scheme 5) instead of the 3,5-
diphenylpyridine originally used in the rotaxane assembly
reaction as the former minimizes signal overlapping to yield
1
simpler H NMR spectrum than the latter.
A detailed multidimensional NMR spectroscopic investigation
allowed unambiguous assignments of the resonances for
rotaxane 24.[ Furthermore, comparison of the H NMR spectra
of rotaxane 24, thread 15 and macrocycle 6[29] (Figure 1) provide
unequivocal evidence for the interlocked architecture. The
pyrrolic nuclei (HB) resonances split into several signals, while
the meso signals (HA) and those of the ortho‐biphenyl rings
19]
1
(
HC‐H) appear in duplicate for 24 because of the unsymmetrical
threaded axle that renders the porphyrinate protons magnetically
inequivalent. Imidazole axial coordination is confirmed by the
large shielding observed for protons HM, HN, and HO as they
experience the strong ring‐current effect of the porphyrin
aromatic system. Resonances for protons associated with the
cyclopropane moiety (HV, HX* and HW) are significantly shielded
in the rotaxane, compared to those in the non‐interlocked
thread 15, with HW dramatically shifting upfield (Δδ = 6.21 ppm).
This shift is indicative of the cyclopropane moiety on the thread
III
being held very close to the Co /porphyrinate subunit. In
contrast, the signals for HS, HT, and HU show much smaller
shielding (Δδ = 0.49, 0.37 and 0.74 ppm, respectively) than
those observed for the cyclopropane residue. Therefore, the
macrocycle component seems to preferentially stay over the
half‐thread bearing the carbonyl group. Congruently, the protons
on the trityl‐stoppering groups (HP, HQ and HR) experience
distinct chemical environments in 24 and split into multiple
signals, with HR′ shifting upfield (Δδ = 3.47 ppm), indicating that
the macrocycle component partially encapsulates the
phenoxy‐ester ring on the corresponding trityl‐stopper group.
Two‐dimensional NOESY NMR analysis (Figure 8) reveals
NOEs between protons HV, HX, HW, and HR′ of the thread
component and nuclei HG of the macrocyclic subunit, confirming
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the proposed structure for 24. Under the conditions investigated
(
entry 7, Table 1), the NMR data suggest that macrocycle 7
selectively yields rotaxanes as the trans diastereoisomer, which
is in agreement with the high trans diastereoselectivity observed
by Zhang and coworkers when investigating chiral acyclic
Co(II)porphyrinates in the presence of nitrogen-base additives
as catalytic systems for asymmetric cyclopropanation
reactions.[
17n]
Figure 9. Partial 13C NMR spectra (125 MHz, CDCl
top), rotaxane 24 (middle) and thread 15 (bottom).
3
, 298 K) of macrocycle 6
(
carbonyl moieties on the macrocycle and thread components,
respectively. The carbonyl stretching mode occurring at lower
frequency indicates weakening of the C=O bond on the thread
and strongly suggests donation of electronic density to the
CoIII ion by the carbonyl oxygen atom.[30]
Interactions between carbonyl residues and cobalt(III)
complexes pentacoordinate to nitrogen-based ligands are rare
and, to the best of our knowledge, has only been observed by
Taube and colleagues in (methylacetate)pentaammincobalt(III)
perchlorate complexes under very restricted conditions due to
the inherent kinetic lability of the carbonyl ligand.[30] For
comparison purpose, oxidation of noninterlocked macrocycle 7
with AgBF4 in the presence of 1.0 equiv. of imidazole using
methyl or ethyl acetates as solvents yields bis-imidazole-
Co(III)porphyrinate 22 along with several unidentified porphyrinic
byproducts. Furthermore, no sign of formation of the heteroleptic
complex was observed by FTIR when running the oxidation
Figure 8. Two dimensional NOESY NMR spectrum of rotaxane 24 recorded in
3
CDCl at 298 K and 400 MHz. Proton labelling corresponds to that shown in
Scheme 5. The dashed lines designate spatial cross signals between protons
R, X* (protons X are diastereotopic), W and R’ on the thread component and
nuclei G on the macrocycle subunit, which confirms the interlocked structure
proposed for rotaxane 24.
4
reaction with macrocycle 7 in CCl in the presence of 1 equiv. of
imidazole and a large excess (10.0 equiv.) of methyl acetate.
Therefore, this unusual C=O•••Co(III) coordinative bond is
enforced by the mechanical bond, whose restricted molecular
environment keeps the carbonyl moiety on the thread
component close to the Co(III) ion, hence kinetically stabilizing
the interaction. However, addition of acetonitrile as a nonbulky
exogenous ligand disrupts this weak interaction, thereby
The strong shielding experienced by HW and HR′ suggests that
III
the Co /porphyrinate should be axially coordinated to the
carbonyl group on the thread to form
a
heteroleptic
hexacoordinate complex.[30] 13C NMR investigation confirms this
intercomponent interaction in solution (Figure 9). The carbonyl
resonances of the free‐base porphyrin macrocycle precursor
liberating the macrocycle component to move along the thread
as revealed by the collapse of the well-defined 1H NMR
6[29]
and 15 appear at δ = 172.1 and 171.4 ppm, respectively,
whereas the spectrum of 24 shows three resonances for its
carbonyl groups. The signals at δ = 170.9 and 170.8 ppm are
assigned to the carbonyl groups on the ring component, which
are magnetically inequivalent due to the unsymmetrical threaded
axle, whereas the carbonyl resonance on the thread shifts
spectrum originally observed for rotaxane 24.
upfield to 170.6 (Δδ
=
1.5 ppm) when compared to
non‐interlocked 15, thus confirming its proximity to the porphyrin
core.
This intercomponent interaction is also present in the solid state.
The FTIR‐ATR spectrum of 24 (Figure 10) shows two distinct
and intense ester carbonyl stretching bands at νCOstretch = 1754
cm−1 and νCOstretch = 1667 cm , which we attribute to the
−1
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Experimental Section
General Information. All chemicals were purchased from Sigma-Aldrich
and Labsynth and used without further purification unless otherwise
noted. For moisture-sensitive reactions, solvents were freshly distilled.
Dichloromethane (DCM) and toluene (MePh) were dried over calcium
hydride, whereas 1,4-dioxane and tetrahydrofuran (THF) were dried
using the sodium/benzophenone system. Anhydrous dimethylformamide
(DMF) was used as received. Technical grade ethyl acetate (EtOAc) and
hexanes were used as received in extractions and as eluent in column
chromatography purifications. All syntheses were carried out using
Schlenk line techniques. Moisture-sensitive liquids were transferred by
cannula or syringe. The progress of the reactions was monitored by thin-
layer chromatography (TLC) whenever possible. TLC was performed
using pre-coated aluminum plates (SiliaPlate from Silicycle with 200 m
thickness) containing a 254 nm fluorescent indicator. Preparative TLC
was carried out on glass plates coated with silica gel 60 PF254 containing
4 2
gypsum (CaSO •0.5 H O, 28-32%, w/w) with particle size 90%  55 m
from Merck EMD Millipore Corporation. Column chromatography was
carried out using Fluka Silica Gel 60 (230-400 mesh particle size).
Compounds 8, 9 and 3,5-diphenylpyridine were synthesized following the
synthetic protocols described elsewhere.[19] For a complete structural
characterization, including spectra of the compounds reported in the
present manuscript, see our previous communication.[19] 1H, 13C and
COSY NMR spectra were obtained on either a Bruker AVANCE 250 (250
MHz) or a Bruker AVANCE 400 (400 MHz) or a Bruker AVANCE 500
Figure 10. Carbonyl stretching frequency region of the FTIR-ATR spectra of
macrocycle 7 (red line), thread 15 (blue line) and rotaxane 24 (green line).
Conclusions
The present work demonstrates that semi-rigid porphyrin-based
macrocycles with well-define cavities are compelling macrocyclic
receptors for the AMT synthesis of interlocked molecules.
Specifically, macrocycles containing Co(II)porphyrinate subunits
when in the presence of appropriate monodentate nitrogen-
based additives to function as axial ligands can efficiently
promote radical carbene transfer reactions to olefins that occur
exclusively through the cavity of the macrocycle to afford
cyclopropane-linked rotaxanes in excellent yields. The critical
experimental parameters (concentration, solvent effects, type
and bulkiness of the axial ligand and reagent stoichiometry) that
influences the outcome of the radical carbene transfer
processes have been established through isolation and
identification of the products originated from the rotaxane
assembly reaction. The methodology described herein validates
the redox cooperative action between the carbene species and
the Co(II) ions established by de Bruin’s and Zhang’s groups as
a powerful synthetic strategy to gain control over otherwise
unselective radical-type reactions. As porphyrin ligands can
virtually coordinate any transition metals, many organometallic
reactions and even new reactivities can now be explored as
synthetic protocols for the AMT synthesis of interlocked
molecules. Such variety of reactions should result in the design
of rotaxanes and catenanes with rich structural diversity, which
will potentially translate into innovative mechanically-linked
molecular machines able to perform elaborate tasks and
functions. We are currently investigating the use of the present
methodology in the design and preparation of interlocked
polymers as well as molecular machines and motors.
(500 MHz), in both cases using deuterated solvents as the lock. The
spectra were collected at 298 K, and chemical shifts reported in parts per
1
million (δ, ppm) were referenced to residual solvent peak ( H, CDCl
3
at
.26 ppm; 13C, CDCl
7
3
at 77.16 ppm). In the assignments, the chemical
shift (in ppm) is given first, followed, in parentheses, by multiplicity (s,
singlet; d, doublet; t, triplet; m, multiplet; br, broad), the values of the J-
coupling constants in Hz (if applicable), the number of protons implied
and finally the assignment. Residual solvent peaks and eventual aliphatic
impurities were assigned according to literature.[31] Two dimensional
NOESY NMR spectra were acquired on a Bruker AVANCE 400 (400
MHz) using CDCl
time. Low resolution mass spectra (LRMS) were afforded from an Agilent
GC-MS piece of equipment, model 5975C, equipped with
3
as deuterated solvent at 298 K and 400 ms mixing
a
monoquadrupole detector in positive mode and electron impact (EI)
source. High-resolution mass spectra (HRMS) were recorded on a Q-
TOF (ESI-QTOF) equipment operating in positive mode. MALDI-TOF
mass spectra were recorded in either a Bruker Daltonics Microflex LT
MALDI-TOF MS or in a Bruker Daltonics Autoflex III Smartbean equipped
with LIFT TOF/TOF technology spectrometers. The mass spectra
represent an average over 512 consecutive laser shots in linear mode
using (1E,3E)-1,4-diphenylbuta-1,3-diene (DPB) as matrix (unless
otherwise noted), which was purchased from Aldrich. The mass scale
was calibrated using the peptide calibration standard purchase from
Bruker and -cyano-4-hydroxycinnamic acid (HCCA) as matrix. Data
processing was carried out using the software package Compass for Flex
series available from Bruker. Mentioned m/z values correspond to
monoisotopic masses. FTIR spectra were obtained from an Agilent Cary
6
30 spectrometer equipped with Attenuated Total Reflection (ATR)
accessory and 4 cm- resolution. All samples were analyzed in the solid
state. UV-Vis spectra were obtained from an Agilent Cary 50
spectrometer with 1.0 nm resolution. All samples were analyzed in
1
dichloromethane solutions (10-5 mol/L) at room temperature and under N
atmosphere in quartz cuvettes with 1 cm width.
2
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General Procedure for the Active-Metal-Template Synthesis of
Rotaxanes. For the success of this protocol, rigorous exclusion of
oxygen from the reaction mixture is mandatory. In a dried oven 25 mL
Schlenk flask, macrocycle 7 (1 equiv.), 3,5-diphenylpyridine (1 equiv. for
the experiments with addition of axial ligands) were dissolved in freshly
170.79; 170.55; 155.65; 148.94; 148.83; 147.09; 146.59; 144.98; 144.78;
144.69; 144.66; 144.54; 143.99; 143.93; 143.87; 143.83; 143.67; 143.11;
142.88; 139.97; 139.45; 138.87; 137.15; 136.45; 136.42; 135.63; 135.59;
135.32; 135.23; 135.19; 134.90; 134.85; 134.62; 132.23; 131.92; 131.25;
131.18; 130.76; 130.15; 130.12; 130.01; 129.51; 128.00; 127.91; 127.67;
127.59; 126.71; 126.63; 126.55; 126.29; 126.03; 121.23; 120.23, 120.14;
2
distilled and thoroughly N -degassed toluene to yield a reaction solution
at about 0.05 M. The reaction mixture was stirred under an inert
atmosphere at room temperature for 10 min, followed by addition of half-
thread 9 (1.00 or 5.00 equiv.) as a solid. Half-thread 8 (1.00 or 1.20
equiv.) was added as a solid (for experiment with portion-wise addition,
119.83;119.76; 116.81; 115.35; 114.33; 107.43; 106.62; 69.82; 64.49;
64.41; 34.19; 33.94; 32.09; 28.74; 28.27; 28.16; 25.12; 24.47; 24.33;
18.65; 15.51. MALDI-TOF (DPB): found m/z 1683.28 [M – imidazole
0.20 equiv. every 2.0 h) to the reaction flask under magnetic stirring at
+
Co. UV-Vis (DCM), 10-5
axial ligand] ; 1751.35 calculated for C117H N O
91 6 7
room temperature. After the final addition of 8, the reaction mixture was
stirred at room temperature for 6 h. The total reaction time was 18 h for
both the single and portion-wise experiments. The crude mixture was
concentrated under reduced pressure and dissolved in a minimum
volume of dichloromethane (DCM). The purification process should be
mol/L, λmax (nm): 312 (imidazole), 422 (Soret), 529 (Q-band). FTIR (ATR),
-
1

(cm ): 1754 (C=O stretching vibrational mode on the ring component);
667 (C=O stretching vibrational mode on the thread component).
1
X-ray diffraction. The X-ray intensity data were collected using a Bruker
Kappa Apex II DUO diffractomer equipped with a Bruker APEX CCD
detector (λ = 1.54178 Å). Experiments were performed with a fine-focus
carried out under N
hexanes/DCM gradient (1:4, v/v) as eluent allowed isolation of excess of
half-thread 9 (R = 0.86) and noninterlocked thread 15 (R = 0.59). The
2 2
atmosphere. Column chromatography (SiO ) using
sealed tube radiation source (Cu K
temperature and under nitrogen atmosphere. The frames were integrated
with the Bruker SAINT[32] software package using
narrow-frame
α
radiation, λ = 1.54178 Å) at low
f
f
porphyrin products were isolated by preparative TLC. In a first run, using
hexanes/DCM (4:1, v/v) as eluent, the target rotaxane 14 was isolated as
a
algorithm. The integration of the data using a monoclinic unit cell yielded
a total of 79067 reflections to a maximum θ angle of 68.7° (0.82 Å
resolution). The final cell constants of a = 41.830(3) Å, b = 13.9450(10) Å,
the first porphyrin fraction (R
= 0.27). In a second run, using DCM/acetone (5:1, v/v) as eluent,
complexes 12 and 13 (R = 0.22) were isolated as a mixture.
f
= 0.36), followed by the rotaxane byproduct
(R
f
f
3
c = 25.543(2) Å, β = 116.316(6)°, V = 13355.7(19) Å , are based upon
the refinement of the XYZ-centroids of 9392 reflections above 2σ(I) with
Synthesis of Co(II)porphyrinate-based rotaxane 14. In a typical
experiment, macrocycle 7 (45.0 mg, 53 mol) and 3,5-diphenylpyridine
7
.041° < 2θ < 126.1°. Data were corrected for absorption effects using
the Multi-Scan method (SADABS 2016/2)[33]. The ratio of minimum to
maximum apparent transmission was 0.685. Using Olex2,[34] the
(12.1 mg, 53 mol) were dissolved in 1 mL of toluene under an inert
[
35]
atmosphere and the reaction mixture was stirred for 10 min at room
temperature. Half-thread 9 (0.1200 g, 265 mol) was added, followed by
the addition of five portions of half-thread 8 (4.3 mg, 10.6 mol, 2.0 h
elapsed time from one addition to the other). After the final addition of 8,
the reaction mixture was stirred for additional 6 h at room temperature,
totalizing 18 h reaction time. Purification was carried out following the
general procedure to afford the target rotaxane in 95% yield (84.70 mg).
structure was solved with the ShelXT structure solution program using
Intrinsic Phasing and refined with the XL[ refinement package using
Least Squares minimisation. All nonhydrogen atoms were refined
anisotropically and hydrogen atoms were added to the structure in
idealized positions and further refined according to the riding model. The
aliphatic molecular loop was highly disordered as shown by difference
Fourier map, which is characterized by a continuous of electron density
36]
(
see Figure S11 in S. I.). The disorder was modeled by two positions for
R
f
= 0.36 (hexanes/DCM, 1:4). MALDI-TOF (DPB): found m/z 1683.28
the double ester and two positions from one of aromatic rings. The
chemical equivalent bond lengths and angles were kept all with the same
values with the SADI instruction. The instruction ISOR was used to
restrain the atomic displacement of disordered atoms. The occupation of
each disordered part has converged to 0.498 and 0.502. The solvent
mask routine implemented in Olex2 was used and 59 electrons was
found in 273 Å. It is compatible with 1.5 diethyl ether molecule which was
used in the crystallization procedure. The complementary information
about voids localization can be found in the cif file (CCDC number
1971223) and in the Supporting Information. Those data are provided free
of charge.
+
Co. UV-Vis (DCM), 10-5 mol/L,
[M] ; 1683.60 calculated for C114
H N O
88 4 7
-
1
λmax (nm): 407 (Soret), 521, 552 (Q-bands). FTIR (ATR),  (cm ): 1752-
1720 (Broad band corresponding to the C=O stretching vibrational mode
on the ring and thread components).
Synthesis of Co(III)porphyrinate-based rotaxane 24. In a 25 mL
Schlenk flask, rotaxane 14 (36.0 mg, 22 mol) and imidazole (2.0 mg, 33
4
mol) were dissolved in 4 mL of DCM. AgBF (6.40 mg, 33 mol) was
added and the reaction mixture was stirred for 12 h at room temperature.
The crude product was filtered on a Celite pad to remove insoluble
materials and concentrated under reduced pressure. Recrystallization
from DCM/diethyl ether afforded rotaxane 24 in 94% yield (35 mg). 1
NMR (500 MHz, CDCl ), δ (ppm): 9.94 (s, 1H, H ); 9.89 (s, 1H ); 9.32 (d,
.0 Hz, 1H, HB1); 9.23 (d, 4.9 Hz, 1H, HB2); 9.21 (d, 5.1 Hz, 1H, HB3); 9.19
d, 5.1 Hz, 1H, HB4); 9.16 (d, 4.8 Hz,1H, HB5); 9.14 (d, 4.8 Hz, 1H, HB6);
.01 (d, 4.7 Hz, 1H, HB7); 8.79 (d, 4.4 Hz, 1H, HB8); 8.56 (s, 1H, NH); 8.20
d, 7.2 Hz, 1H, H ); 8.08 (d, 7.2 Hz, 1H, H ); 7.89 (d, 7.3 Hz, 1H, H );
.85 (d, 7.4 Hz, 1H, H ); 7.75-7.74 (m, 4H, H +H ); 7.42-7.28 (m, 10H,
); 7.26-6.93 (m, 30H, H +H +H +H ); 6.34 (d, 7.2 Hz, 2H, H ); 6.29 (d,
.7 Hz, 2H, HM’) 5.92 (t, 8.0 Hz, 4H, H ); 5.86 (d, 8.0 Hz, 2H, H ); 4.43 (s,
H, H ); 4.15 (s, 1H, H ); 3.45 (d, 7.8 Hz, 2H, HN’); 2.02-1.84 (m, 4H,
); 1.11-0.96 (m, 6H, H ); 0.69-0.56 (m, 4H, H ); 0.31 (m, 1H, H ); -0.02
d, 1.2 Hz, 1H, H ); -0.37 (m, 1H, H ); -0.57 (m, 1H, HS’); -0.96 (d, 1.2 Hz,
H, HV’); -4.17 (br, 1H, H ), δ (ppm): 170.89;
). 13C NMR (125 MHz, CDCl
H
Acknowledgements
3
A
A
5
The authors are grateful to the Fundação de Amparo à Pesquisa
do Estado de São Paulo (FAPESP) for financial support (Grants
(
9
2
(
013/22160‐0 and 2015/23761‐2) and fellowship for LAF
2017/06752‐5). JDMJ thanks Conselho Nacional de
Desenvolvimento Científico Tecnológico (CNPq) for the
(
C
C
F
7
F
D
E
e
H
L
H
L
M
P
Q
research fellowship (#301899/2014‐2). We also thank the
Brazilian Synchrotron Light Laboratory (LNLS) for the X‐ray
experiments and Prof. Anita J. Marsaioli for the MALDI‐TOF
piece of equipment.
8
2
G
N
O
U
H
K
J
I
R
(
V
S
1
T
3
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Chemistry - A European Journal
10.1002/chem.201905602
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Keywords: carbenes • radical chemistry • porphyrins •
rotaxanes • cyclopropanation
Illescas, I. Nierengarten, B. Delavaux-Nicot, E. Ortí, N. Martín, J.-F.
Nierengarten. J. Am. Chem. Soc. 2016, 138, 15359-15367. g) P. Mondal, S. P.
Rath. Chem. Eur. J. 2016, 22, 5607-5619.
[
5] a) I. Paul, A. Goswami, N. Mittal, M. Schmittel. Angew. Chem. Int. Ed. 2017,
7, 354-358; Angew. Chem. 2017, 130, 360-364. b) S. Cantekin, A. J.
[
1] a) Y.-W. Lin, Coord. Chem. Rev. 2017, 336, 1-27; b) C. R. Randall, L. Que
5
Jr. in Handbook of Metal-Ligand Interactions in Biological Fluids: Bioinorganic
Chemistry, Vol. 1 (Ed.: G. Berthon), Marcel Dekker, New York, 1995, pp-388-
Markvoort, J. A. A. W. Elemans, A. E. Rowan, R. J. M. Nolte. J. Am. Chem.
Soc. 2015, 137, 3915-3923. c) T. Ikeda, T. Tsukahara, R. Lino, M. Takeuchi, H.
Noji. Angew. Chem. Int. Ed. 2014, 53, 10082-10085; Angew. Chem. 2014, 126,
3
98.c) J. P. Collman, P. S. Wagenknecht, J. E. Hutchison. Angew. Chem. Int.
Ed. 1994, 33, 1537-1554; Angew. Chem. 1994, 106, 1620-1639. d) M. N
Alberti, Y. Polyhach, M. D. Tzirakis, L. Toedtli, G. Jeschke, F. Diederich. Chem.
Eur. J. 2016, 22, 10194-10202. e) J-F. Longevial, S. Clement, J. A. Wytko, R.
Ruppert, J. Weiss, S. Richeter. Chem. Eur. J. 2018, 24, 15442-15460. f) A.
Tikad, H. Fu, C. M. Sevrain, S. Laurent, J.-F. Nierengarten, S. P. Vincent.
Chem. Eur. J. 2016, 22, 13147-13155. g) J. A. A. W. Elemans, Nolte, R. J. M.
Roeland. Chem. Comm. 2019, 55, 9590-9605.
1
0246-10249. d) O. Penon, F. Marsico, D. Santucci, L. Rodriguez, D. B.
Amabilino, L. Perez-Garcia, J. Porph. Phthal. 2012, 16, 1293-1302. e) R.
Pawlak, S. Fremy, S. Kawai, T. Glatzel, H. Fang, L.-A. Fendt, F. Diederich, E.
Meyer. ACS Nano 2012, 6, 6318-6324.
[
6] a) H. Zhu, H. Wang, B. Shi, L. Shangguan, W. Tong, G. Yu, Z. Mao, F.
Huang, Nat. Comm. 2019, 10, 1-10. b) L. Sobotta, P. Skupin-Mrugalska, J.
Piskorz, J. Mielcarek. Eur. J. Med. Chem. 2019, 175, 72-106. c) M. Oezkan, Y.
Keser, S. E. Hadi, D. Tuncel. Eur. J. Org. Chem. 2019, 21, 3534-3541. d) J.
Massiot, V. Rosilio, N. Ibrahim, A. Yamamoto, V. Nicolas, O. Konovalov, M.
Tanaka, A. Makky, Chem. Eur. J. 2018, 24, 19179-19194. e) M. A. Rajora, J.
W. H. Lou, G. Zheng. Chem. Soc. Rev. 2017, 46, 6433-6469. f) C. Ornelas-
Megiatto, T. B. Becher, J. D. Megiatto, Jr. Curr. Top. Med. Chem. 2015, 15,
[
2] a) Y.-M Zhao, G.-Q. Yu, F.-F. Wang, P.-J. Wei, J.-G. Liu, Chem. Eur. J.
019, 25, 3726-3739. b) P. Gotico, B. Boitrel, R. Guillot, M. Sircoglou,
Quaranta, A. Z. Halime, W. Leibl, A. Aukauloo. Angew. Chem. Int. Ed. 2019,
8, 4504-4509; Angew. Chem. 2019, 131, 4552-4557. c) D. Carminati, E.
Gallo, C. Damiano, A. Caselli, D. Intrieri, Eur. J. Inorg. Chem. 2018, 48, 5258-
262. d) W. Mtangi, F. Tassinari, K. Vankayala, J. A. Vargas, B. Adelizzi, A. R.
A. Palmans, C. Fontanesi, E. W. Meijer, R. Naaman. J. Am. Chem. Soc. 2017,
39, 2794-2798. e) P. J. Thomassen, S. Varghese, E. J. A. Bijsterveld, P.
2
5
5
1
236-1256.
[
7] For a few recent contributions and some reviews, see: a) M. Maares, M. M.
1
Ayhan, K. B. Yu, A. O. Yazaydin, K. Harmandar, H. Haase, J. Beckmann, Y.
Zorlu, G. Yuecesan. Chem. Eur. J. 2019, 25, 11214-11217. b) R. Haldar, K.
Batra, S. M. Marschner, A. B. Kuc, S. Zahn, R. A. Fischer, S. Bräse, T. Heine,
C. Woell. Chem. Eur. J. 2019, 25, 7847-7851. c) B. Wang, T. Rhauderwiek, A.
K. Inge, H. Xu, T. Yang, Z. Huang, N. Stock, X. Zou. Chem. Eur. J. 2018, 24,
Thordarson, J. A. A. W. Elemans, A. E. Rowan, R. J. M. Nolte. Eur. J. Org.
Chem. 2015, 23, 5246-5253. f) S. S. Nurttila, W. Brenner, J. Mosquera, K. M.
van Vliet, J. R. Nitschke, J. N. H. Reek, Chem. Eur. J. 2019, 25, 609-620.
[
3] a) Y. Zhao, J. R. Swierk, J. D. Megiatto, Jr., B. D. Sherman, W. J.
Youngblood, D. Qin, D. M. Lentz, A. L. Moore, T. A. Moore, D. Gust, T. E.
Mallouk. Proc. Natl. Acad. Sci. USA 2012, 109, 15612-15616. b) C. M. Davis,
K. Ohkubo, A. D. Lammer, D. S. Kim, Y. Kawashima, J. L. Sessler, S.
Fukuzumi. Chem. Comm. 2015, 51, 9789-9792. c) A. Tebo, C. Herrero, A.
Aukauloo in Handbook of Porphyrin Science, Vol 34 (Eds.: K. M. Kadish, K. M.
Smith), World Scientific, Singapore, 2014, pp. 195-237. d) J. D. Megiatto, Jr.,
D. Patterson, B. D. Sherman, T. A. Moore, D. Gust, A. L. Moore. Chem.
Comm., 2012, 48, 4558-4560. e) T. Nakazono, A. R. Parent, K. Sakai. Chem.
Eur. J. 2015, 21, 6723-6726. f) A. Antoniuk-Pablant, Y. Terazono, B. J.
Brennan, B. D. Sherman, J. D. Megiatto, Jr., G. W. Brudvig, A. L. Moore, T. A.
Moore, D. Gust. J. Mater. Chem. A, 2016, 4, 1-10. g) J. D. Megiatto, Jr., A.
Antoniuk-Pablant, B. D. Sherman, G. Kodis, M. Gervaldo, T. A. Moore, A. L.
Moore, D. Gust., Proc. Natl. Acad. Sci. USA 2012, 109, 15578-15583. h) J. D.
Megiatto, Jr., D. D. Méndez-Hernández, M. Tejeda-Ferrari, A.-L. Teillout, M. J.
Llansola-Portolés, G. Kodis, O. G. Poluektov, T. Rajh, V. Mujica, T. L. Groy, D.
Gust, T. A. Moore, A. L. Moore, Nat. Chem. 2014, 6, 423-428. i) J.
Ravensbergen, A. Antoniuk-Pablant, B. D. Sherman, G. Kodis, J. D. Megiatto,
Jr., D. D. Méndez-Hernández, R. N. Frese, R. Van Grondelle, T. A. Moore, A.
L. Moore, D. Gust, J. T. M. Kennis, J. Phys. Chem. B, 2015, 119, 12156-
17429-17433. d) B. Abeykoon, T. Devic, J.-M. Greneche, A. Fateeva, A. B.
Sorokin. Chem. Comm. 2018, 54, 10308-10311. e) N. Huang, K. Wang, H.
Drake, P. Cai, J. Pang, J. Li, S. Che, L. Huang, Q. Wang, H.-C. Zhou. J. Am.
Chem. Soc. 2018, 140, 6383-6390. f) R. Makiura, H. Kitagawa, Eur. J. Inorg.
Chem. 2010, 24, 3715-3724.
[
8] a) S. W. Hewson, K. M. Mullen. Eur. J. Org. Chem. 2019, 21, 3358-3370.
b) M. Wolf, A. Ogawa, M. Bechtold, M. Vonesch, J. A. Wytko, K. Oohora, S.
Campidelli, T. Hayashi, D. M. Guldi, J. Weiss. Chem. Sci. 2019, 10, 3846-
3
853. c) L. de Juan-Fernandez, P. W. Munich, A. Puthiyedath, B. Nieto-Ortega,
S. Casado, L. Ruiz-Gonzalez, E. M. Perez, D. M. Guldi. Chem. Sci. 2018, 9,
779-6784. d) N. Mihara, Y. Yamada, H. Takaya, Y. Kitagawa, K. Igawa, K.
6
Tomooka, H. Fujii, K. Tanaka, Chem. Eur. J. 2019, 25, 3369-3375. e) B.
Delavaux-Nicot, A. H. Ben, I. Nierengarten, T. Minh Nguyet Trinh, E.
Meichsner, M. Chesse, M. Holler, R. Abidi, E. Maisonhaute, J.-F. Nierengarten.
Chem. Eur. J. 2018, 24, 133-140. f) T. H. Ngo, J. Labuta, G. N. Lim, W. A.
Webre, F. D'Souza, P. A. Karr, J. E. M. Lewis, J. P. Hill, K. Ariga, S. M. Goldup.
Chem. Sci. 2017, 8, 6679-6685. g) Y. Miyazaki, C. Kahlfuss, A. Ogawa, T.
Matsumoto, J. A. Wytko, K. Oohora, T. Hayashi, Weiss, J. Chem. Eur. J. 2017,
23, 13579-13582. h) O. I. van den Boomen, R. G. E. Coumans, N. Akeroyd, T.
12163. j) J. D. Megiatto, Jr., D. I. Schuster in Fullerenes: Principles and
P. J. Peters, P. P. J. Schlebos, R. de Gelder, J. A. A. W. Elemans, R. J. M.
Nolte, A. E. Rowan. Tetrahedron 2017, 73, 5029-5037. i) D. R. Kohn, L. D.
Movsisyan, A. L. Thompson, H. L. Anderson,Org. Lett. 2017, 19, 348-351. j) Y.
Yamada, T. Kato, K. Tanaka, Chem. Eur. J. 2016, 22, 12371-12380. k) R. G.
E. Coumans, J. A. A. W. Elemans, A. E. Rowan, R. J. M. Nolte. Chem. Eur. J.
Applications, Vol 1 (Eds.: F. L. de la Puente, J.-F. Nierengarten), Royal
Society of Chemistry, Cambridge, 2012, pp. 354-385. k) J. D. Megiatto, Jr., D.
I. Schuster in Handbook of Carbon Nanomaterials Vol 1 (Eds.: F. D'Souza, K.
M. Kadish), World Scientific Press, London, 2011, pp. 207-244.
[
4] a) F. J. Rizzuto, J. P. Carpenter, J. R. Nitschke. J. Am. Chem. Soc. 2019,
41, 9087-9095. b) R. Haver, L. Tejerina, H.-W. Jiang, M. Rickhaus, M.
2013, 19, 7758-7770. l) A. Brown, P. D. Beer. Dalton Trans. 2012, 41, 118-129.
1
m) M. Jakob, A. Berg, H. Levanon, D. I. Schuster, J. D. Megiatto, Jr. J. Phys.
Chem. C 2011, 115, 24555-24563. n) M. Jakob, A. Berg, H. Levanon, D. I.
Schuster, J. D. Megiatto, Jr. J. Phys. Chem. A 2011, 115, 5044-5052. o) J. D.
Megiatto, Jr., R. Spencer, D. I. Schuster. Org. Lett. 2009, 11, 4152-4155. p) J.-
S. Marois, J.-F. Morin. Langmuir 2008, 24, 10865-10873. q) J. D. Megiatto, Jr.,
Jirasek, I. Grubner, H. J. Eggimann, L. M. Herz, H. L. Anderson, J. Am. Chem.
Soc. 2019, 141, 7965-7971. c) A. Koc, R. Khan, D. Tuncel. Chem. Eur. J.
2
018, 24, 15550-15555. d) P. Mondal, S. Sarkar, S. P. Rath, Chem. Eur. J.
017, 23, 7093-7103. e) J. Mosquera, B. Szyszko, S. K. Y. Ho, J. R. Nitschke.
2
Nat. Comm. 2017, 8, 14882-14888. f) L. Moreira, J. Calbo, J. Aragó, B. M.
This article is protected by copyright. All rights reserved.

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10.1002/chem.201905602
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K. Li, D. I. Schuster, A. Palkar, M. A. Herranz, L. Echegoyen, S. Abwandner, G.
C. Lee. Chem. Rev. 2019, 119, 4293-4356. d) X. Zhou, H. Zhang. Chem. Eur.
J. 2018, 24, 8962-8973. e) K.-S. Feichtner, V. H. Gessner. Chem. Comm.
2018, 54, 6540-6553. f) M. Melaimi, R. Jazzar, M. Soleilhavoup, G. Bertrand.
Angew. Chem. Int. Ed. 2017, 56, 10046-10068; Angew. Chem. 2011, 129,
10180-10203. g) O. Torres, A. Pla-Quintana. Tetrahedron Lett. 2016, 57,
3881-3891. h) Y. Jiang, R. Sun, X.-Y Tang, M. Shi. Chem. Eur. J. 2016, 22,
17910-17924. i) A. DeAngelis, R. Panish, J. M. Fox. Acc. Chem. Res. 2016,
49, 115-127. j) A. I. O. Suarez, V. Lyaskovskyy, J. N. H. Reek, J. I. van der
Vlugt, B. de Bruin. Angew. Chem. Int. Ed. 2013, 52, 12510-12529; Angew.
Chem. 2013, 125, 12740-12760. k) D. Intrieri, A. Caselli, E. Gallo. Eur. J.
Inorg. Chem. 2011, 33, 5071-5081. l) M. P. Doyle, R. Duffy, M. Ratnikov, L.
Zhou. Chem. Rev. 2010, 110, 704-724. m) M. A. Sierra, M. Gomez-Gallego, R.
Martinez-Alvarez, Chem. Eur. J. 2007, 13, 736-744. n) H.-J. Lu, Z. P. Zhang.
Chem. Soc. Rev. 2011, 40, 1899–1909. o) W. I. Dzik, Z. P. Zhang, B. de Bruin.
Inorg. Chem. 2011, 50, 9896–9903. p) Y. Hu, X. P. Zhang, Top. Curr. Res.
2012, 327, 147–162. q) V. Sinha, B. Pribanic, B. de Bruin, M. Trincado, H.
Grutzmacher. Chem. Eur. J. 2018, 24, 5513-5521. r) P. F. Kuijpers, J. I. van
der Vlugt, S. Schneider, B. de Bruin. Chem. Eur. J. 2017, 23, 13819-13829. s)
C.-M. Che, V. K.-Y Lo, C.-Y. Zhou, J.-S. Huang. Chem Soc. Rev. 2011, 40,
1950-1975. t) J. Demarteau, A. Debuigne, C. Detrembleur. Chem. Rev. 2019,
119, 6906-6955.
De Miguel, D. M. Guldi. J. Chem. Phys. B 2010, 114, 14408-14419.
[
9] a) Y. Yamada, R. Itoh, S. Ogino, T. Kato, K. Tanaka. Angew. Chem. Int. Ed.
017, 56, 14124-14129; Angew. Chem. 2017, 129, 14312-14317. b) S. P.
2
Black, D. M. Wood, F. B. Schwarz, T. K. Ronson, J. J. Holstein, A. R.
Stefankiewicz, C. A. Schalley, J. K. M. Sanders, J. R. Nitschke. Chem. Sci.
2016, 7, 2614-2620. c) A. Brown, M. J. Langton, N. L. Kilah, A. L. Thompson,
P. D. Beer. Chem. Eur. J. 2015, 21, 17664-17675. d) M. Juricek, J. C. Barnes,
N. L. Strutt, N. A. Vermeulen, K. C. Ghooray, E. J. Dale, P. R. McGonigal, A. K.
Blackburn, A.-J. Avestro, J. F. Stoddart. Chem. Sci. 2014, 5, 2724-2731. e) V.
Raymont, H. Wilson, M. Pfrunder, J. C. McMurtrie, K. M. Mullen, New J. Chem.
2013, 37, 893-900. f) M. Han, H.-Y. Zhang, L.-X. Yang, Z.-J. Ding, R.-J.
Zhuang, Y. Liu. Eur. J. Org. Chem. 2011, 36, 7271-7277. g) M. J. Langton, J.
D. Matichak, A. L. Thompson, H. L. Anderson. Chem. Sci. 2011, 2, 1897-1901.
h) M. Beyler, V. Heitz, J.-P. Sauvage. J. Am. Chem. Soc. 2010, 132, 4409-
4417. i) J. D. Megiatto, Jr., D. I. Schuster, S. Abwandner, G. de Miguel, D. M.
Guldi. J. Am. Chem. Soc. 2010, 132, 3847-3861. j) J. A. Faiz, V. Heitz, J.-P.
Sauvage. Chem. Soc. Rev. 2009, 38, 422-442. k) J. D. Megiatto, Jr., D. I.
Schuster. J. Am. Chem. Soc. 2008, 130, 12872-12873. l) J. D. Megiatto, Jr., D.
I. Schuster. Chem. Eur. J. 2009, 15, 5444-5448. m) J. D. Megiatto, Jr., D. I.
Schuster. New J. Chem. 2010, 34, 276-286. n) J. D. Megiatto, Jr., R. Spencer,
D. I. Schuster, D. I. J. Mat. Chem. 2011, 21, 1544-1550. o) J. D. Megiatto, Jr.,
D. I. Schuster. Org. Lett. 2011, 13, 1808-1811.
[13] Interestingly, Leigh, Goldup and collaborators have cleverly explored the
kinetic lability of bipydridine-based complexes to investigate the mechanism of
the “click” reactions used for the final assembly of the interlocked molecules,
as well as to develop AMT protocols in which the metal template ion is added
in catalytic rather than the usual required stoichiometric amounts. For details,
see ref. 11k.
[
10] J. E. Beves, B. A. Blight, C. J. Campbell, D. A. Leigh, R. T. McBurney,
Angew. Chem. Int. Ed. 2011, 50, 9260-9327; Angew. Chem. 2011, 123, 9428-
499.
11] a) A. Brown, T. Lang, K. M. Mullen, P. D. Beer. Org. Biomol. Chem. 2017,
5, 4587-4594. b) J. J. Danon, D. A. Leigh, P. R. McGonigal, J. W. Ward, J.
9
[
1
[14] a) G. De Bo, M. A. Y. Gall, M. O. Kitching, S. Kuschel, D. A. Leigh, D. J.
Tetlow, J. W. Ward J. Am. Chem. Soc. 2017, 139, 10875-10879. b) B.
Lewandowski, G. De Bo, J. W. Ward, M. Papmeyer, S. Kuschel, M. J.
Aldegunde, P. M. E. Gramlich, D. Heckmann, S. M. Goldup, D. M. D’Souza, A.
E. Fernandes, D. A. Leigh, Science, 2013, 339, 189-193. c) P. Thordarson, E.
J. A. Bijsterveld, A. E. Rowan, R. J. M. Nolte. Nature 2003, 424, 915–918. d) S.
Varghese, J. A. A. W. Elemans, A. E. Rowan, R. J. M. Nolte. Chem. Sci. 2015,
6, 6050-6058.
Wu. J. Am. Chem. Soc. 2016, 138, 12643-12647. c) M. J. Langton, Y. Xiong,
P. D. Beer. Chem. Eur. J. 2015, 21, 18910-18914. d) A. Noor, S. C. Moratti, J.
D. Crowley. Chem. Sci. 2014, 5, 4283-4290. e) P. E. Glen, J. A. T. O'Neill, A.-
L. Lee. Tetrahedron 2013, 69, 57-68. f) P. E. Barran, H. L. Cole, S. M. Goldup,
D. A. Leigh, P. R. McGonigal, M. D. Symes, J. Wu, M. Zengerle. Angew.
Chem. Int. Ed. 2011, 50, 12280-12284; Angew. Chem. 2011, 123, 12574-
12574. g) H. M. Cheng, D. A. Leigh, F. Maffei, P. R. McGonigal, A. M. Z.
Slawin, J. Wu. J. Am. Chem. Soc. 2011, 133, 12298-12303. h) S. M. Goldup,
D. A. Leigh, R. T. McBurney, P. R. McGonigal, A. Plant. Chem. Sic. 2010, 1,
[15] a) D.-S. Kim, W.-J. Park, C.-H. Jun. Chem. Rev. 2017, 117, 8977-9015.
b) D. G. H. Hetterscheid, J. I. van der Vlugt, B. de Bruin, J. N. H. Reek, Angew.
Chem. Int. Ed. 2009, 48, 8178-8181; Angew. Chem. 2009, 121, 8324-8327.
[16] c) M. Lankelma, A. M. Olivares, B. de Bruin. Chem. Eur. J. 2019, 25,
5658-5663. d) A. Chirila, M. B. Brands, B. de Bruin. J. Catat. 2018, 361, 347-
360. e) A. Chirila, K. M. van Vliet, N, D, Paul, B. de Bruin. Eur. J. Inorg. Chem.
2018¸ 20-21, 2251-2258. f) A. S. Karns, M. Goswami, B. de Bruin, B. Chem.
Eur. J. 2018, 24, 5253-5258. g) C. te Grotenhuis, N. van den Heuvel, J. I. van
der Vlugt, B. de Bruin. Angew. Chem. Int. Ed. 2018, 57, 140-145; Angew.
Chem. 2009, 130, 146-151. h) M. Goswami, B. de Bruin, W. I. Dzik. Chem.
Comm. 2017, 53, 4382-4385. i) P. F. Kuijpers, M. J. Tiekink, W. B. Breukelaar,
D. L. J. Broere, N. P. van Leest, J. I. van der Vlugt, J. I., J. N. H. Reek, B. de
Bruin. Chem. Eur. J. 2017, 23, 7945-7952. j) P. F. Kuijpers, J. I. van der Vlugt,
S. Schneider, B. de Bruin. Chem. Eur. J. 2017, 23, 13819-13829. k) S. H. A. M.
Leenders, R. Becker, T. Kumpulainen, B. de Bruin, T. Sawada, T. Kato, M.
Fujita, J. N. H. Reek. Chem. Eur. J. 2016, 22, 15468-15474. l) M. Goswami, V.
Lyaskovskyy, S. R. Domingos, W. J. Buma, S. Woutersen, O. Troeppner, I.
Ivanović-Burmazović, H. Lu, X. Cui, X. P. Zhang, E. J. Reijerse, S. DeBeer, M.
M. van Schooneveld, F. F. Pfaff, K. Ray, B. de Bruin. J. Am. Chem. Soc. 2015,
137, 5468-5479. m) M. Otte, P. F. Kuijpers, O. Troeppner, I. Ivanović-
Burmazović, J. N. H. Reek, B. de Bruin. Chem. Eur. J. 2013, 20, 4880-4884.
n) N. D. Paul, A. Chirila, H. Lu, Z. P. Zhang, B. de Bruin. Chem. Eur. J. 2013,
383-386. i) S. M. Goldup, D. A. Leigh, T. Long, P. R. McGonigal, M. D. Symes,
J. Wu. J. Am. Chem. Soc. 2009, 131, 15924-15929. j) J. D. Crowley, S. M.
Goldup, A.-L. Lee, D. A. Leigh, R. T. McBurney. Chem. Soc. Rev. 2009, 38,
1530-1541. k) V. Aucagne, Vincent; J. Berna, J. D. Crowley, S. M. Goldup, K.
D. Haenni, 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. l) F.
Modicom, E. M. G. Jamieson, E. Rochette, S. M. Goldup. Angew. Chem. Int.
Ed. 2019, 58, 3875-3879; Angew. Chem. 2019, 131, 3915-3919. m) M. A.
Jinks, A. de Juan, M. Denis, C. J. Fletcher, M. Galli, E. M. G. Jamieson, F.
Modicom, Z. Zhang, S. M. Goldup. Angew. Chem. Int. Ed. 2018, 57, 14806-
14810; Angew. Chem. 2018, 130, 15022-15026. n) J. E. M. Lewis, F. Modicom,
S. M. Goldup. J. Am. Chem. Soc. 2018, 140, 4787-4791. o) M. Denis, S. M.
Goldup. Nat. Rev. Chem. 2017, 1, 61. p) J. E. M. Lewis, P. D. Beer, S. J. Loeb,
S. M. Goldup. Chem. Soc. Rev. 2017, 46, 2577-2591. q) J. E. M. Lewis, J.
Winn, L. Cera, S. M. Goldup. J. Am. Chem. Soc. 2016, 138, 16329-16336. r) E.
A. Neal, S. M. Goldup. Chem. Sci. 2015, 6, 2398-2404. s) H. Lahlali, K. Jobe,
M. Watkinson, S. M. Goldup. Angew. Chem. Int. Ed. 2011, 50, 4151-4155;
Angew. Chem. 2011, 123, 4237-4241.
[
12] For reviews, see: a) J. W. Herndon. Coord. Chem. Rev. 2018, 356, 1-114.
b) L. Wang, J. Xiao. Top. Curr. Chem. 2016, 374, 1-55. c) S. W. Roh, K. Choi,
This article is protected by copyright. All rights reserved.

Chemistry - A European Journal
10.1002/chem.201905602
FULL PAPER
1
9, 12953-12958. o) H. Lu, W. I. Dzik, X. Xu, L. Wojtas, B. de Bruin, X. P.
[24] A. Penoni, R. Wanke, S. Tollari, E. Gallo, D. Musella, F. Ragaini, F.
Demartin, S. Cenini. Eur. J. Inorg. Chem. Soc. 2003, 7, 1452-1460.
[25] X. Cui, X. Xu, L.-M. Jin, L. Wojtas, X. P. Zhang. Chem. Sci. 2017, 6, 1219-
1224.
Zhang, X. P. J. Am. Chem. Soc. 2011, 133, 8518-8521. p) I. Wojciech, W. I.
Dzik, X. P. Zhang, B. de Bruin. Inorg. Chem. 2011, 50, 9896-9903 q) M. Otte,
P. F. Kuijpers, O. Troeppner, I. Ivanović‐Burmazović, J. N. H. Reek, B. de
Bruin. Chem. Eur. J. 2014, 20, 4880-4884. r) M. Otte, P. F. Kuijpers, O.
Troeppner, I. Ivanović‐Burmazović, J. N. H. Reek, B. de Bruin. Chem. Eur. J.
[26] a) P. E. Ellis Jr., J. E. Linard, T. Szymanski, R. D. Jones, J. R. Budge, F.
Basolo. J. Am. Chem. Soc., 1980, 102, 1889-1896. b) D. P. Rillema, C. M.
Wicker Jr., R. D. Morgan, L. F. Barringer, L. A. Scism. J. Am. Chem. Soc.
1982, 104, 1276-1281. c) J. R. Budge, P. E. Ellis, Jr., R. D. Jones, J. E. Linard,
T. Szymanski, F. Basolo, J. E. Baldwin, R. L. Dyer. J. Am. Chem. Soc. 1979,
101, 4762-4763. d) D. V. Stynes, H. C. Stynes, B. R. James, J. A. Ibers. J. Am.
Chem. Soc. 1973, 95, 1796-1801. e) N. G. Bichan, E. N. Ovchenkova, N. O.
Kudryakova, A. A. Ksenofontov, M. S. Gruzdev, T. N. Lomov. New J. Chem.
2018, 42, 12449-12456. f) Y. Terazono, B. O. Patrick, D. H. Dolphin. Inorg.
Chim. Acta 2003, 346, 265-269. g) J. W. Lauher, J. A. Ibers. J. Am. Chem.
Soc. 1974, 96, 4447-4452. h) J. S. Summers, J. L. Petersen, A. M.
Stohenberg. J. Am. Chem. Soc. 1994, 116, 7189-7195.
2013, 19, 10170-10178.
[17] a) Y. Hu, K. Lang, J.-R. Tao, M. K. Marshall, Q.-G. Cheng, X. Cui, L.
Wojtas, X. P. Zhang. Angew. Chem. Int. Ed. 2019, 58, 2670–2674; Angew.
Chem. 2019, 131, 2696-2700. b) X. Wen, Y. Wang, X. P. Zhang. Chem. Sci.
2018, 9, 5082–5086. c) Y. Wang, X. Wen, X. Cui, X. P. Zhang. J. Am. Chem.
Soc. 2018, 140, 4792–4796. d) H.-L. Jiang, K. Lang, H.-J. Lu, L. Wojtas, X. P.
Zhang. J. Am. Chem. Soc. 2017, 139, 9164–9167. e) Y. Wang, X. Wen, X. Cui,
L. Wojtas, X. P. Zhang. J. Am. Chem. Soc. 2017, 139, 1049–1052. f) X. Cui, X.
Xu, L.-M. Jin, L. Wojtas, X. P. Zhang. Chem. Sci. 2015, 6, 1219–1224. g) H.-J.
Lu, C.-Q. Li, H.-L. Jiang, C. L. Lizardi, X. P. Zhang. Angew. Chem. Int. Ed.
2
014, 53, 7028–7032; Angew. Chem. 2014, 126, 7148-7152. h) N. D. Paul, S.
Mandal, M. Otte, X. Cui, X. P. Zhang, B. de Bruin. J. Am. Chem. Soc. 2014,
36, 1090–1096. i) X. Cui, X. Xu, L. Wojtas, M. M. Kim, X. P. Zhang. J. Am.
[27] a) A. Werner, Z. Anorg. Chem. 1893, 3, 267-330; b) K. M. Kadish, L. A.
Bottomley, D. Beroiz. Inorg. Chem. 1978, 17, 1124-1129.
1
[28] a) L. Zhang, K. S. Chan. Organometallics 2007, 26, 679-684. b) M. P.
Doyle. Chem. Rev 1986, 86, 919-939. c) W. I. Dzik, J. N. H. Reek, B. de Bruin.
Chem. Eur. J. 2008, 14, 7594–7599.
Chem. Soc. 2012, 134, 19981–19984. j) X. Xu, H.-L. Lu, J. V. Ruppel, X. Cui,
S. L. de Mesa, L. Wojtas, X. P. Zhang. J. Am. Chem. Soc. 2011, 133, 15292–
1
5295. k) V. Lyaskovskyy, A. I. O. Suarez, H.-J. Lu, H.-L. Jiang, X. P. B. de
[29] We use the 1H NMR spectrum of free-base macrocycle 6 for comparison
as Co(II)porphyrinate-based macrocycle 7 is a paramagnetic compound.
[30] J. K. Hurst, H. Taube. J. Am. Chem. Soc. 1968, 90, 1174-1177.
[31] H. E. Gottlieb, V. Kotlyar, A. Nudelman. J. Org. Chem. 1997, 62, 7512-
7515.
Bruin. J. Am. Chem. Soc. 2011, 133, 12264–12273. l) H.-J. Lu, X. P. Zhang.
Chem. Soc. Rev. 2011, 40, 1899–1909. m) W. I. Dzik, X. Xu, X. P. Zhang, J. N.
H. Reek, B. de Bruin. J. Am. Chem. Soc. 2010, 132, 10891-10902. n) Y. Chen,
X. P. Zhang. Synthesis 2006, 10, 1697–1700.
[
18] a) S. V. Kirner, C. Henkel, D. M. Guldi, J. D. Megiatto, Jr. D. I. Schuster.
[32] SAINT v8.38a, Bruker AXS Inc.: Madison, WI, USA, 2017.
[33] SADABS-2016/2; Bruker AXS Inc.: Madison, WI, USA, 2016.
[34] O. V. Dolomanov, L. J. Bourhis, R. J. Gildea, J. A. K. Howard, H.
Puschmann. J. Appl. Cryst. 2009, 42, 339-341.
Chem. Sci. 2015, 6, 7293-7304. b) J. D. Megiatto, Jr., D. I. Schuster, G. de
Miguel, S. Wolfrum, D. M. Guldi. Chem. Mat. 2012, 24, 2472-2485. c) S. V.
Kirner, D. M. Guldi, J. D. Megiatto, Jr., D. I. Schuster. Nanoscale 2015, 7,
1145-1160. d) J. D. Megiatto, Jr., D. I. Schuster, D. M. Guldi. Chem. Soc. Rev.
[35] G. M. Sheldrick. Acta Cryst. 2015, A71, 3-8.
2020, 49, 8-20.
[36] G. M. Sheldrick. Acta Cryst. 2008, A64, 112-122.
[
19] A. F. P. Alcantara, L. A. Fontana, V. H. Rigolin, Y. F. S. Andrade, M. A.
Ribeiro, W. P. Barros, C. Ornelas, J. D. Megiatto, Jr. Angew. Chem. Int. Ed.
018, 57, 8979-8983; Angew. Chem. 2018, 130, 9117-9121.
20] a) Y. Song, R. E. Haddad, S.-L. Jia, S. Hok, M. M. Olmstead, D. J. Nurco,
2
[
N. E. Schore, J. Zhang, J.-G. Ma, K. M. Smith, S. Gazeau, J. Pécaut, J.-C.
Marchon, C. J. Medforth, J. A. Shelnutt. J. Am. Chem. Soc. 2005, 127, 1179-
1192. b) M.S. Somma, C. J. Medforth, N. Y. Nelson, M. M. Olmstead, R. G.
Khoury, K. M. Smith. Chem. Comm. 1999, 13, 1221-1222. c) J. A. Shelnutt,
X.-Z. Song, J.-G. Ma, S.-L. Jia, W. Jentzen, C. J. Medforth. Chem. Soc. Rev.
1998, 27, 31-42. d) M. O. Senge, W. W. Kalisch. Inorg. Chem. 1997, 36, 6103-
6116. e) C. J. Medforth, C. M. Muzzi, K. M. Shea, K. M. Smith, R. J. Abraham,
S.-L Jia, J. A. Shelnutt. J. Chem. Soc., Perkin Trans. 2 1997, 4, 839-844. f) C.
J. Medforth, C. M. Muzzi, K. M. Shea, K. M. Smith, R. J. Abraham, S.-L. Jia, J.
A. Shelnutt. Chem. Soc., Perkin Trans. 2 1997, 4, 833-838. g) R. E. Haddad, S.
Gazeau, J. Pécaut, J.-C. Marchon, C. J. Medforth, J. A. Shelnutt. J. Am. Chem.
Soc. 2003, 125, 1253-1268.
[
21] J. S. Lindsey, I. C. Schreiman, H. C. Hsu, P. C. Kearney, A. M. Mar-
Guerettaz, J. Org. Chem. 1987, 52, 827-836.
22] The high dilution of the samples (1 x 10-2 M) precludes intermolecular ring
[
current effects that manifest upon aggregation in higher concentrated samples.
See, K. M. Smith, R. J. Abraham, H. Pearson. Tetrahedron 1982, 38, 2441-
2
449.
23] a) N. V. Chizhova, R. S. Kumeev, N. Z. Mamardashvili. Russ. J. Inorg.
Chem., 2013, 58, 740-743. b) J. Yang, P. Huang. Chem. Mater., 2000, 12,
693-2697.
[
2
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Arthur F. P. Alcântara, Liniquer A.
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Control over the Redox Cooperative
Mechanism of Radical Carbene
Transfer Reactions for the Efficient
Active-Metal-Template Synthesis of
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[
2]Rotaxanes
Controlling radical behavior: manipulation of the redox
cooperative properties of carbenoid species and Co(II) ions
results in a powefull methodology for the synthesis of
[
2]rotaxanes through the active-metal-template technique.
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