X-ray crystallographic analysis of a tailor-made bis(phthalocyaninato)- TbIII single-molecule magnet as a fundamental unit for supramolecular spintronic devices

Article abstract of DOI:10.1002/ejic.201402421

The single-crystal X-ray diffraction analysis of the title compound, the pyrene-substituted unsymmetrical bis(phthalocyaninato)terbium(III) Single-Molecule Magnet (SMM) [Pc-Tb-Pc]⁰ (1) (Pc = dianion of phthalocyanine, P* = dianion of phthalocyanine decorated with six flexible hexyl chains and one 4-pyren-1yl-butoxy group), was carried out. Both phthalocyaninato ligands in 1 are distorted from planarity and, therefore, adopt a biconcave shape. Effective π-π interactions between the molecules lead to the formation of head-to-tail π dimers. These dimers are stacked in the crystal, forming adjacent, parallel columns, the axes of which are tilted by 30° with respect to the C₄ axes of the macrocycles. Herein, we also report the synthesis and characterization of the new isostructural Dy (compound 2) and Ho (compound 3) analogues of 1. The structure of a [Pc-Tb-Pc] SMM was determined. A single-crystal X-ray diffraction analysis revealed an effective intermolecular π-π interaction leading to the formation of π dimers, which are stacked with neighboring dimers in parallel columns with an axis tilted by 30° with respect to the C4 axis of individual molecules. Isostructural Dy and Ho analogues were synthesized and characterized.

Full text of DOI:10.1002/ejic.201402421

FULL PAPER
DOI:10.1002/ejic.201402421
X-ray Crystallographic Analysis of a Tailor-Made
Bis(phthalocyaninato)-TbIII Single-Molecule Magnet as a
Fundamental Unit for Supramolecular Spintronic Devices
Svetlana Klyatskaya,*[a] Andreas Eichhöfer,[a] and
Wolfgang Wernsdorfer[b]
Keywords: X-ray diffraction / Structure elucidation / Lanthanide complexes / Pi interactions / Single-molecule magnets
The single-crystal X-ray diffraction analysis of the title com-
pound, the pyrene-substituted unsymmetrical bis(phthalo-
cyaninato)terbium(III) Single-Molecule Magnet (SMM) [Pc–
Tb–Pc*]0 (1) (Pc = dianion of phthalocyanine, P* = dianion of
phthalocyanine decorated with six flexible hexyl chains and
one 4-pyren-1yl-butoxy group), was carried out. Both phthal-
ocyaninato ligands in 1 are distorted from planarity and,
therefore, adopt a biconcave shape. Effective π–π interactions
between the molecules lead to the formation of head-to-tail
π dimers. These dimers are stacked in the crystal, forming
adjacent, parallel columns, the axes of which are tilted by
30° with respect to the C4 axes of the macrocycles. Herein,
we also report the synthesis and characterization of the new
isostructural Dy (compound 2) and Ho (compound 3) ana-
logues of 1.
including non-magnetic substrates, such as HOPG (highly
ordered pyrolytic graphite),[10,11] Au(111), Cu(111),
Cu(100)[12–15], and magnetic substrates, such as Ni films,[16]
ultrathin Co and Ni films,[17] a perovskite manganite of
LSMO (lanthanum strontium manganite)[18], and substrates
with antiferromagnetic Mn and CoO layers.[19] Therefore,
bis(phthalocyaninato)lanthanide(III) complexes could serve
as the fundamental units in single-molecule devices, which
includes the possibility to electrically read out the spin state
of a single nuclear spin, which could be of great importance
for a wide range of applications, from nanospintronics to
quantum computing.[20] Indeed, this molecule has been suc-
cessfully fabricated into different spintronic devices by di-
rect coupling in molecular junctions,[21,22] by indirect cou-
pling within double magnetic quantum dots (QD) based on
sp2-carbon materials, such as SWNT and graphene,[23–28]
and by supramolecular self-assembly of the custom-made
complex [Pc–Tb–Pc*]0 (1),[9] which shows promising appli-
cations.
Introduction
The
bis(phthalocyaninato)terbium(III)
complexes
[TbPc2]–/0/+ (Pc = dianion of phthalocyanine) as well as the
isostructural dysprosium(III) and holmium(III) com-
pounds, discovered by Ishikawa and co-workers,[1–6] are the
first examples of mononuclear metal complexes behaving
like single-molecule magnets (SMMs). They exhibit large
magnetic anisotropies, slow relaxation, and quantum tun-
neling of magnetization (QTM) in a temperature range sig-
nificantly higher than that of all other known SMMs, which
provides an unique quantum fingerprint of the molecule on
the magnetic-reversal mechanism.[7] For the terbium com-
plexes, the out-of-phase component of the dynamic mag-
netic susceptibility appears well above 40 K because of the
unusually high energy barrier ΔE for the reversal of the
magnetization.[8]
These striking magnetic properties and their robust mono-
atomic structure (unlike in most d-metal cluster SMMs)
provided the possibility to chemically tune the molecular
properties of these systems and, at the same time, to main-
tain their metallic core and, hence, their SMM behavior.[9]
Moreover, the properties of this molecule remain un-
changed when it is grafted onto different substrates
Results and Discussion
Because of the flexibility of long hydrocarbon chains and
similar substituents, single crystals of phthalocyanine deriv-
atives with long flexible chains (such as alkyl and alkoxy)
are not easy to obtain and X-ray diffraction analyses of
substituted compounds remain few.[29] Nevertheless, there
are exceptions, and these include a number of examples of
octasubstituted derivatives, where alkyl,[30,31] alkoxy,[32–34]
or crown-ether[35] groups are located at peripheral and non-
peripheral positions. To the best of our knowledge, there is
[a] Institute of Nanotechnology, Karlsruhe Institute of Technology
(KIT),
76344 Eggenstein-Leopoldshafen, Germany
E-mail: svetlana.klyatskaya@kit.edu
www.int.kit.edu
[b] Institut Néel, CNRS,
38042 Grenoble Cedex 9, France
Supporting information for this article is available on the
WWW under http://dx.doi.org/10.1002/ejic.201402421.
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no X-ray diffraction analysis of bis(phthalocianinato) deriv- nitrogen atoms (Niso) of the phthalocyaninato ligands [N1–
atives bearing one unsymmetrical phthalocyanine ligand N4 (Pc) and N5–N8 (Pc*)]. The central terbium ion lies
(Pc*).
1.425 Å from the Niso mean plane of the Pc ligand and
This paper describes a single-crystal X-ray diffraction 1.378 Å from the Niso mean plane of the Pc* ligand bearing
study of the unsymmetrical bis(phthalocyaninato)ter- peripheral substituents. The calculated distance between the
bium(III) complex 1. Single crystals suitable for X-ray dif- two Niso mean planes is 2.824 Å. This value is slightly larger
fraction analysis were obtained as fine dark green needles than that reported for other terbium bis(phthalocyanine)
by slow diffusion of EtOH into a solution of complex 1 in materials (2.67–2.70 Å).[36–38]
a hexane/CHCl3 mixture. A view of the molecular structure
Unlike the previously described unsubstituted lanthanide
of 1 is depicted in Figure 1. Compound 1 crystallizes in the phthalocyanine structures,[8,12,39,40] both phthalocyaninato
¯
triclinic space group P1 with two molecules per unit cell ligands of 1 are distorted from planarity and, therefore,
(Table 1). The terbium ion occupies a central position in adopt a biconcave shape. Nevertheless, the distortions of
the complex and is eightfold coordinated by the isoindole the Pc and Pc* ligands are not equal and more pronounced
Figure 1. ORTEP plot of one molecule of 1 with ellipsoids drawn at the 50% probability level for all non-hydrogen atoms. Top view (left)
indicating the numbering scheme. Atoms labelled n represent the carbon atoms Cn. Side view (right): the chains at C46 and C38 have
been omitted for clarity. There is disorder in the hexyl chains at C53 and C54. The disorder model and the positions of the hydrogen
atoms are omitted for clarity.
Table 1. Crystallographic data for compound (1).
1·1.4CHCl3·0.5C2H5OH
Elemental formula[a]
Formula weight [g/mol]
Crystal system
C119.40H116.90Cl4.20N16O1.50Tb
2107.80
triclinic
¯
P1
Space group
Unit cell dimensions
a, b, c [Å]
14.249(3), 18.994(4), 23.114(5)
α, β, γ [°]
72.30(3), 78.81(3), 75.53(3)
5723(2)
2
0.771
150(2)
62627
22040
0.0537
17247
Cell volume, V [Å3]
Number of formula units/cell, Z
Absorption coefficient, μ(λ) [mm–1]
Temperature [K]
Total number of reflections measured
Number of unique reflections measured
Rint for equivalents
Number of “observed” reflections, I Ͼ 2σI
Final R indices, R1 (“observed” data)[b], wR2 (all data)[c]
0.0514, 0.1422
[a] Non-integer numbers of atoms result from partial disorder of the hexyl groups, which could not be completely modeled. [b] R1
=
2
2 2
Σ||Fo| – |Fc||/Σ|Fo|. [c] wR2 = {Σ[w(Fo – Fc ) ]/Σ[w(Fo2)2]}1/2
.
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for the substituted ligand. In the Pc ligand, the angle be- intermolecular distance of 3.345–3.369 Å (Figure 2, Fig-
tween the Niso plane and the planes of benzene rings are ure S1), which is in a good agreement with the general val-
about 7°. In the Pc* ligand, the angle between the Niso ues observed for π–π stacking.[42–44] Secondly, the dimers
plane and the planes of two alternating benzene rings with translate in the crystal with an offset, which leads to the
hexyl substituents is 18°, whereas the other set bearing a formation of columns parallel to the b axis (Figure 2). The
pyren-1-yl-butoxy group lies in plane. This suggests that the column axis is tilted by 30° with respect to the C4 axis of
long alkyl chains and the 4-pyren-1yl-butoxy group on the the Pc macrocycle, which is similar to the solvated YPc2
benzene rings have a significant effect on the geometry of compound.[39] The adjacent columns are intercalated with
the phthalocyanine molecular plane. Only two of the six shortest distances of 3.617 Å between benzene rings of Pc
hexyl chains, those attached to atoms C45 and C53, lie ligands from two different columns (Figures S2 and S3).
within the plane of the Pc ring. The chain bound to atom
C39 is pointing down relative to the Pc ligand, whereas the
chains attached to C37, C46, and C54 are facing up. The
skew angel, determined as the rotational angle of the Niso
mean planes with respect to each other, is 41.2°, and it is
in good agreement with published values for Tb bis(phthal-
ocyaninato) complexes.[12] On the basis of the distance be-
tween two hydrogen atoms at hexyl and pyrenyl groups
(H121/H85), the width of one molecule of 1 was estimated
to be approximately 3.4 nm , and the height of the bis-
(phthalocyaninato) core was estimated to be 0.5 nm on the
basis of the distance between the hydrogen atoms H8 and
H53 of the Pc and Pc* rings, respectively.
Figure 2. View of the packing in 1 along the b axis. All H atoms
and –C6H13 groups are omitted for clarity. Different color codes
are indicating π dimers.
Phthalocyanines and their derivatives typically have a
The shortest intermetallic Tb–Tb distance of 13.084 Å
large conjugated molecular electronic structure. The domi- was found between adjacent, parallel columns, whereas the
nant π–π interactions between phthalocyanine molecules Tb–Tb distance is much larger (16.976 Å) within the π di-
usually lead to 1D nanostructures.[40] Nevertheless, tuning mer. Complex 1 crystallizes with molecules of ethanol and
the intermolecular interaction towards more complex self- chloroform in the crystal lattice. Each π dimer is sur-
assembled nanostructures can be achieved by incorporating rounded by two EtOH and four CHCl3 molecules. Chloro-
functional groups into the phthalocyanine framework.[41] form molecules indicate the formation of hydrogen bonds
Thus, the presence of a 4-pyren-1yl-butoxy group in the with N and H atoms (Cl3C–H···N; CHCl2–Cl···H) of the
molecular structure of 1 with its large conjugated electronic phthalocyanine macrocycles (Figure S4).
structure is expected to induce complexity in the internal
Herein, we also report the synthesis of new isostructural
crystal packing. The crystal packing of [Pc–Tb–Pc*]0 (1) is pyrene-substituted bis(phthalocyaninato)-LnIII complexes
depicted in Figure 2. There are two principal features of the [Ln = Dy (compound 2), Ho (compound 3)] (Scheme 1).
packing. Firstly, despite the deformed molecular structure The complexes 2 and 3 were synthesized according to a
and the saucer conformation adopted by the Pc and Pc* published procedure[9] from two different phthalocyaninato
rings, effective π–π interactions exist between the molecules lithium salts (5 and 6) and Ln(acac)3 hydrate (Ln = Dy or
of 1. Thus, pairs of complex molecules form head-to-tail π Ho) in a 1:1:1 ratio. The synthesis of 4,5-dihexylbenzene
dimers, which is evidenced by the overlap of the pyrenyl (9) was significantly improved by using the Pd/Cu-catalyzed
group and the Pc* ring of a second molecule with a shortest Sonogashira cross coupling of dichlorophthalonitrile (7)
Scheme 1. Synthesis of [Pc–Ln–Pc*]0 complexes, where Ln = Dy (for 2), Ho (for 3). (a) Li/MeOH; (b) 1-chloronaphthalene, reflux.
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Figure 3. MALDI-TOF spectra of complexes 2 (a) and 3 (b); here, the experimental and calculated (red lines) values of the relative
abundances of the isotopic ions are summarized.
with hex-1-yne, which was followed by catalytic hydrogena-
The electrochemical behavior of the complexes 2 and 3
tion with gaseous H2 (Scheme S1). This approach allowed was studied by cyclic voltammetry (CV) with a platinum
us to increase the total yield of the key building block 4 working electrode and solutions in dichloromethane con-
from 10%[9] to 60%. The MALDI-TOF mass spectra of 2 taining 0.1 m [nBu4N][ClO4]. The cyclic voltammograms of
and 3 both showed intense signals for the molecular ion 2 and 3 are very similar to those of the unsymmetrical Tb
[M – H+] at m/z = 1963 and m/z = 1965, respectively, and bis(phthalocyanine) 1,[9] and three quasi-reversible one-elec-
this proves their unsymmetrical nature. In both cases, the tron redox processes appear near +0.64, –0.19, and –0.61 V
molecular ion was the most abundant high-mass ion with a (Figure S6). Thus, the neutral forms of the sandwich com-
distinct isotopic distribution. The relative abundances of plexes 2 and 3 undergo one oxidation and two reduction
the isotopic ions are in good agreement with the simulated steps as well.
spectra, as depicted in Figure 3, where the experimental and
calculated values are summarized.
The SMM behavior of 1 was reported before,[9] whereas
the SMM behavior of complexes 2 and 3 is evidenced by
The nature of complexes 2 and 3 was further confirmed the opening of hysteresis cycles in the subkelvin tempera-
by UV/Vis–NIR and NMR spectroscopy. The complexes ture range (Figure 4), as acquired with a micro-SQUID
have a one-electron-oxidized-ligand “sandwich” structure, magnetometer.[48] The hysteresis behavior was investigated
in which the unpaired electron is delocalized on both
phthalocyanine ligands.[45,46] Similar to the parent Tb com-
plex 1, the lanthanide bis(phthalocyaninato) complexes 2
and 3 exhibit two bands at 490 and 922 nm (the egǞa1u
transitions), which are characteristic of a Pc π radical, as
well as another broad band in the range 1200–1700 nm,
which corresponds to intramolecular-charge-transfer (ICT)
(Figure S5). The two absorption bands at 673 and 328 nm
were assigned to the Q band and the Soret band, respec-
tively. The weak shoulder attached to the Q band (605 nm)
has been reported to be due to weak π–π interactions occur-
ring between the two Pc/Pc* ligands. All the NIR bands
disappear upon reduction of 2 and 3 with hydrazine hydrate
(1%, v/v). Moreover, good NMR spectroscopic data in
CDCl3 could only be obtained after reduction, which sup-
ports the assumption that a radical form of the complexes
1
2 and 3 is present. The H NMR spectra are quite complex
and show many superimposed multiplets, which confirms
Figure 4. Micro-SQUID hysteresis cycles of 2 (left) and 3 (right),
the unsymmetrical nature of 2 and 3, whereas the unsubsti-
recorded at different temperatures (a) and scan rates (b). The ap-
plied magnetic field was aligned along the easy axis of magnetiza-
tuted LnPc2 complexes[8,47] are symmetrical and have rather
simple NMR spectra.
tion.
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the SQUEEZE option within the PLATON[51] program package,
and a total number of 84 electrons were found in a potential sol-
vent-accessible area of 280 Å3.
as a function of temperature and field sweeping rate. The
hysteresis loops exhibit increasing hysteresis with decreasing
temperature at a constant sweep rate (Figure 4, a) and in-
creasing hysteresis with increasing field sweep rate at a con- An attempt to improve the quality of the model by recording a
dataset for 1 at the synchrotron facility ANKA (KIT, Germany)
with a stronger X-ray source resulted only in comparable data.
stant temperature (Figure 4, b), as expected for the super-
paramagnet-like properties of a SMM.
CCDC-912132 (for 1) contains the supplementary crystallo-
graphic data for this paper. These data can be obtained free of
charge from The Cambridge Crystallographic Data Centre via
www.ccdc.cam.ac.uk/data_request/cif.
Conclusions
The molecular structure of the SMM [Pc–Tb–Pc*] (1),
which was intensively studied over the last years, as it is the
active unit in spintronic devices,[21–28] was determined by
means of single-crystal X-ray diffraction analysis. The crys-
tallographic analysis revealed that both phthalocyaninato
ligands are slightly distorted from planarity. Despite this,
effective π–π interactions exist between the molecules,
which lead to the formation of head-to-tail π dimers. A ho-
mologous series of the new unsymmetrical mononuclear py-
renyl-containing bis(phthalocyaninato)-based SMMs, [Pc–
Ln–Pc*] with Ln = Dy (2), Ho (3) was successfully synthe-
sized. Their spectroscopic and electrochemical properties
are almost identical to the parent Tb complex 1, and their
SMM behavior is evidenced by the appearance of hysteresis
cycles for both compounds in the subkelvin temperature
range, which is similar to their parent compound 1.[5,6]
These results revealed the outstanding robustness of the
SMM behavior in this series of modified bis(phthalocyanin-
ato)lanthanide(III) complexes.
Magnetic Measurements: Hysteresis cycles were acquired with a
homemade micro-SQUID setup.
General Synthetic Remarks: Reactions requiring an inert gas atmo-
sphere were conducted under argon, and the glassware was oven
dried (140 °C). All reagents were purchased from commercial
sources and used as received. Radial chromatography was per-
formed with a Chromatotron 7924 T, with plates prepared from
Silica gel 60PF254 containing gypsum. The asymmetrically substi-
tuted phthalocyanine Pc*H2 (compound 4), its lithium salt (com-
pound 5), and 4-(4-pyren-1-yl-butoxy)phthalonitrile (10) were pre-
pared according to literature procedures.[9]
4,5-Bis(hex-1-yn-1-yl)phthalonitrile (8): To a solution of dichloro-
phthalonitrile (7) (5.81 g, 30 mmol) in dry Et3N (300 mL),
Pd(PPh3)4 (200 mg) and CuI (80 mg) were added, and the reaction
mixture was heated to 80 °C. A solution of hex-1-yne (7.3 g,
90 mmol) in 30 mL of Et3N was added dropwise over 20 min. After
the addition was complete, the reaction mixture was heated at re-
flux until 7 had fully reacted (1.5 h, TLC control). The mixture was
poured into ice water (200 mL) and then extracted with diethyl
ether (3ϫ100 mL). The combined organic layers were washed twice
with water and dried with magnesium sulfate. The solvent was re-
moved under reduced pressure, and the residue was purified by
chromatography on SiO2 to afford compound 8 (5.2 g, 65% yield).
1H NMR (CDCl3): δ = 0.96 (t, J = 7 Hz, 6 H), 1.41–1.52 (m, 4 H),
1.60–1.64 (m, 4 H), 2.50 (t, J = 7 Hz, 4 H), 7.72 (s, 2 H) ppm. 13C
NMR (CDCl3): δ = 13.60, 19.49, 21.96, 30.30, 102.30, 113.39,
Experimental Section
X-ray Crystallography: Crystals suitable for single-crystal X-ray dif-
fraction were obtained by slow diffusion of EtOH into a solution
of complex 1 in a hexane/CHCl3 mixture, and they were then se-
lected in perfluoroalkyl ether oil. Single-crystal X-ray diffraction
data of 1 were collected by using graphite-monochromatized Mo-
Kα radiation (λ = 0.71073 Å) with a STOE STADI Vari (Pilatus
Hybrid Pixel Detector). Raw intensity data were collected and
treated with the STOE X-Area software version 1.64. The data
were corrected for Lorentz and polarization effects. Interframe
scaling was done with the implemented program LANA.
114.86, 131.74, 136.39 ppm. NIR–IR (KBr): ν = 2104 (CϵC) cm–1.
˜
C20H20N2 (288.39): calcd. C 83.30, H 6.99, N 9.71; found C 83.35,
H 7.08, N 9.80.
4,5-Dihexylbenzene (9): To a solution of 1,5-bis(hex-1-yn-1-yl)-
phthalonitrile (8) (2.88 g, 10 mmol) in EtOH (150 mL), Pd black/
C (2 g) was added. The reaction was kept at room temperature, and
gaseous H2 was bubbled through the mixture until 8 had fully re-
acted (2.5 h, TLC control). The solids were filtered off, and the
solvent was removed from the filtrate under reduced pressure. The
residue was purified by chromatography on SiO2 to afford com-
pound 9 (2.7 g, 93% yield), which was recrystallized from light pe-
troleum (m.p. 85–89 °C). 1H NMR (CDCl3): δ = 0.90 (t, J = 7 Hz,
6 H), 1.31–1.33 (m, 8 H), 1.36–1.39 (m, 4 H), 1.54–1.60 (m, 4 H),
2.67 (t, J = 7 Hz, 4 H), 7.55 (s, 2 H) ppm. 13C NMR (CDCl3): δ
= 13.61, 19.47, 21.94, 22.17, 30.30, 30.75, 113.56, 114.98, 131.70,
136.79 ppm. NIR–IR (KBr): no band corresponding to (CϵC).
C20H18N2 (286.38): calcd. C 81.03, H 9.52, N 9.45; found C 81.15,
H 9.08, N 9.39.
Synthesis of the Bis(phthalocyaninato)LnIII Complexes 2 and 3: Un-
der a slow stream of Ar, a mixture of PcLi2 (6) (68 mg, 0.13 mmol)
and Ln(acac)3·2H2O (0.13 mmol) in 1-chloronaphthalene (5 mL),
which was percolated through a basic alumina column just before
being used, was heated at 185–195 °C for 1 h until 6 had fully re-
acted. The resulting dark blue solution was cooled down, and 5
(160 mg, 0.11 mmol) was added. The mixture was again heated up
The structure was solved with the direct-methods program
SHELXS of the SHELXTL PC suite programs,[49] and it was re-
fined by using the full-matrix-least-squares program SHELXL.
Crystal data and the results of the refinement are collected in
Table 1. Molecular diagrams were prepared by using Diamond.[50]
In 1, Tb and all C, O, and N atoms were refined with anisotropic
displacement parameters. Two of the hexyl groups (C109–C114 and
C115–C120) showed strong disorder, which was modelled by using
partial-occupancy carbon atoms. For one of these chains (C115–
C120), one carbon atom could not be localized in the difference
Fourier map. For two other hexyl groups, four carbon atoms, which
are situated at the end of the chains (C88, C89, C90, and C96)
could only be refined with half occupancy. Disordered C atoms
were refined isotropically. H atoms were placed in fixed positions.
CHCl3 and C2H5OH solvent molecules were also refined with par-
tial occupancy. Further residual electron density identified within
the crystal lattice of 1 could not be adequately refined. The data
were therefore corrected for the residual electron density by using
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[12] K. Katoh, Y. Yoshida, M. Yamashita, H. Miyasaka, B. K.
Breedlove, T. Kajiwara, S. Takaishi, N. Ishikawa, H. Isshiki,
Y. F. Zhang, T. Komeda, M. Yamagishi, J. Takeya, J. Am.
Chem. Soc. 2009, 131, 9967–9976.
[13] K. Katoh, H. Isshiki, T. Komeda, M. Yamashita, Coord. Chem.
Rev. 2011, 255, 2124–2148.
[14] L. Vitali, S. Fabris, A. M. Conte, S. Brink, M. Ruben, S. Ba-
roni, K. Kern, Nano Lett. 2008, 8, 3364–3368.
[15] S. Stepanow, J. Honolka, P. Gambardella, L. Vitali, N. Abdu-
rakhmanova, T. Tseng, S. Rauschenbach, S. L. Tait, J. Am.
Chem. Soc. 2010, 132, 11900–11901.
[16] A. Lodi Rizzini, C. Krull, T. Balashov, J. J. Kavich, A. Mu-
garza, P. S. Miedema, P. K. Thakur, V. Sessi, S. Klyatskaya, M.
Ruben, S. Stepanow, P. Gambardella, Phys. Rev. Lett. 2011,
107, 177205.
[17] D. Klar, S. Klyatskaya, A. Candini, B. Krumme, K. Kummer,
P. Ohresser, V. Corradini, V. de Renzi, R. Biagi, L. Joly, J.-P.
Kappler, U. Del Pennino, M. Affronte, H. Wende, M. Ruben,
Beilstein J. Nanotechnol. 2013, 4, 320–324.
[18] L. Malavolti, L. Poggini, L. Margheriti, D. Chiappe, P. Gra-
ziosi, B. Cortigiani, V. Lanzilotto, F. B. de Mongeot, P.
Ohresser, E. Otero, F. Choueikani, P. Sainctavit, I. Bergenti,
A. V. Dediu, M. Mannini, R. Sessoli, Chem. Commun. 2013,
49, 11506–11508.
[19] A. Lodi Rizzini, C. Krull, T. Balashov, A. Mugarza, C. Nistor,
F. Yakhou, V. Sessi, S. Klyatskaya, M. Ruben, S. Stepanow, P.
Gambardella, Nano Lett. 2012, 12, 5703–5707.
to 200–210 °C for 1 h until 5 had fully reacted (MALDI-TOF con-
trol). The mixture was then subjected to column chromatography
(basic aluminum oxide, 60 g) with CH2Cl2/hexane (7:4 v/v) as the
eluent. 1-Chloronaphthalene was eluted first. Then, a greenish-blue
band was collected and concentrated to yield a product mixture
{according to MALDI-TOF, the main components are [Pc–Ln–
Pc*]0/– and [Pc*–Ln–Pc–Ln–Pc); minor components are [Pc*–Ln–
Pc*]0/–, [Pc–Ln–Pc]0/–} as a dark blue-green powder.
Ln = Dy (compound 2): Complex 2 was separated from the crude
mixture by column chromatography (basic aluminum oxide) with
CH2Cl2/MeOH (10:1 v/v) as the eluent, which was followed by re-
precipitation from a hexane/CH2Cl2 mixture to afford a deep green
solid of neutral 2 (87 mg, 24% with respect to 5; Rf = 0.38;
CH2Cl2). MALDI-TOF: calcd. for C120H120N16ODy [M – H]+
1963.9143; found 1963.5697 (M+, 100%).
Ln = Ho (compound 3): Complex 3 was separated from the crude
mixture by column chromatography (basic aluminum oxide) with
CH2Cl2/MeOH (10:1 v/v) as the eluent, which was followed by re-
precipitation from a hexane/CH2Cl2 mixture to afford a deep green
solid of neutral 3 (74 mg, 20% with respect to 5; Rf = 0.38;
CH2Cl2). MALDI-TOF: calculated for C120H120N16OHo
[M – H]+ 1965.9160; found 1965.6942 (M+, 100%).
Supporting Information (see footnote on the first page of this arti-
cle): UV/Vis–NIR–IR spectra and CV data of the complexes 2 and
3. Additional packing diagrams, scheme of synthesis of phthalocy-
anine base 4.
[20] L. Bogani, W. Wernsdorfer, Nat. Mater. 2008, 7, 179–186.
[21] R. Vincent, S. Klyatskaya, M. Ruben, W. Wernsdorfer, F. Bale-
stro, Nature 2012, 488, 357–360.
[22] S. Thiele, R. Vincent, M. Holzmann, S. Klyatskaya, M. Ruben,
F. Balestro, W. Wernsdorfer, Phys. Rev. Lett. 2013, 111,
037203(5).
Acknowledgments
[23] S. Sanvito, Nat. Mater. 2011, 10, 484–485.
[24] M. Urdampilleta, S. Klyatskaya, J.-P. Cleuziou, M. Ruben, W.
Wernsdorfer, Nat. Mater. 2011, 10, 502–506.
[25] M. Urdampilleta, N.-V. Nguyen, J.-P. Cleuziou, S. Klyatskaya,
M. Ruben, W. Wernsdorfer, Int. J. Mol. Sci. 2011, 12, 6656–
6667.
[26] M. Ganzhorn, S. Klyatskaya, M. Ruben, W. Wernsdorfer, ACS
Nano 2013, 7, 6225–6236.
This work was supported by Deutsche Forschungsgemeinschaft
(DFG), the European Commission, Seventh Framework Pro-
gramme for Research (MoQuaS, FP7-ICT-2013-10), and the Marie
Curie action EIF-041565 MoST. The authors acknowledge the
KNMF facility (KIT, Germany) for the collection of single-crystal
XRD data. We are also grateful to Gernot Buth and the SCD be-
amline at the Synchrotron Radial Facility – ANKA (KIT, Ger-
many; proposal number NMT34/Ref. 1618).
[27]
M. Lopes, A. Candini, M. Urdampilleta, A. Reserbat-plantey,
V. Bellini, S. Klyatskaya, L. Marty, M. Ruben, M. Affronte, W.
Wernsdorfer, N. Bendiab, ACS Nano 2010, 4, 7531–7537.
A. Candini, S. Klyatskaya, M. Ruben, W. Wernsdorfer, M. Af-
fronte, Nano Lett. 2011, 11, 2634–2639.
H. Shirai, M. Kimura, in: The Porphyrin Handbook (Ed.: K. M.
Kadish), Academic Press, New York, 2003, vol. 19, p. 151–178.
A. Auger, P. M. Burnham, I. Chambrier, M. J. Cook, D. L.
Hughes, J. Mater. Chem. 2005, 15, 168.
M. Helliwell, A. Deacon, K. J. Moon, A. K. Powell, M. J.
Cook, Acta Crystallogr., Sect. B Struct. Sci. 1997, 53, 231–240.
H. Zhang, R. Wang, P. Zhu, Z. Lai, J. Han, C.-F. Choi, D. K. P.
Ng, X. Cui, C. Ma, J. Jiang, Inorg. Chem. 2004, 43, 4740–4742.
Y. Gao, R. Li, S. Dong, Y. Bian, J. Jiang, Dalton Trans. 2010,
39, 1321–1327.
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
[36]
[37]
[38]
[1] N. Ishikawa, M. Sugita, T. Ishikawa, S. Koshihara, J. Am.
Chem. Soc. 2003, 125, 8694–8695.
[2] N. Ishikawa, M. Sugita, T. Ishikawa, S. Koshihara, J. Phys.
Chem. B 2004, 108, 11265–11271.
[3] N. Ishikawa, M. Sugita, N. Tanaka, T. Ishikawa, S. Koshihara,
Inorg. Chem. 2004, 43, 5498–5500.
[4] N. Ishikawa, M. Sugita, Angew. Chem. Int. Ed. 2005, 44, 2931–
2935; Angew. Chem. 2005, 117, 2991.
[5] N. Ishikawa, M. Sugita, W. Wernsdorfer, Angew. Chem. Int.
Ed. 2005, 44, 2931–2935; Angew. Chem. 2005, 117, 2991.
[6] N. Ishikawa, M. Sugita, W. Wernsdorfer, L. L. Ne, A. V. Mar-
tyrs, G. Cedex, J. Am. Chem. Soc. 2005, 127, 3650–3651.
[7] R. Sessoli, D. Gatteschi, A. Caneschi, M. A. Novak, Nature
1993, 365, 141–143.
[8] F. Branzoli, P. Carretta, M. Filibian, G. Zoppellaro, M. J. Graf,
J. R. Galan-Mascaros, O. Fuhr, S. Brink, M. Ruben, J. Am.
Chem. Soc. 2009, 131, 4387–4396.
[9] S. Kyatskaya, J. R. G. Mascarós, L. Bogani, F. Hennrich, M.
Kappes, W. Wernsdorfer, M. Ruben, J. Am. Chem. Soc. 2009,
131, 15143–15151.
[10] M. Gonidec, R. Biagi, V. Corradini, F. Moro, V. De Renzi, U.
Pennino, D. Summa, L. Muccioli, C. Zannoni, D. B. Amabil-
ino, J. Veciana, J. Am. Chem. Soc. 2011, 133, 6603–6612.
[11] J. Gómez-Segura, I. Díez-Pérez, N. Ishikawa, M. Nakano, J.
Veciana, D. Ruiz-Molina, Chem. Commun. 2006, 2866–2868.
H. Zhang, Z. Lai, X. Cui, J. Jiang, K.-I. Machida, J. Alloys
Compd. 2006, 408–412, 1041–1045.
L. A. Lapkina, Y. G. Gorbunova, S. E. Nefedov, A. Y. Tsiv-
adze, Russ. Chem. Bull. Int. Ed. 2003, 52, 1633–1636.
A. G. Gürek, T. Basova, D. Luneau, C. Lebrun, E. Koltsov,
A. K. Hassan, V. Ahsen, Inorg. Chem. 2006, 45, 1667–1676.
M. Safarpour Haghighi, C. L. Teske, H. Homborg, Z. Anorg.
Allg. Chem. 1992, 608, 73–80.
K. Katoh, Y. Yoshida, M. Yamashita, H. Miyasaka, B. K.
Breedlove, T. Kajiwara, S. Takaishi, N. Ishikawa, H. Isshiki,
Y. F. Zhang, T. Komeda, M. Yamagishi, J. Takeya, J. Am.
Chem. Soc. 2009, 131, 9967–9976.
[39]
J. L. Paillaud, M. Drillon, A. Decian, J. Fischer, R. Weiss, R.
Poinsot, A. Herr, Physica. B 1991, 175, 337–348.
Eur. J. Inorg. Chem. 2014, 4179–4185
4184
© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.eurjic.org
FULL PAPER
[40]
[41]
[42]
[47] F. Guyon, A. Pondaven, J.-M. Kerbaol, M. L’Her, Inorg. Chem.
1998, 37, 569–576.
[48] W. Wernsdorfer, N. E. Chakov, G. Christou, Phys. Rev. B 2004,
70, 132413.
[49] G. M. Sheldrick, SHELXTL, PC version 5.1, Bruker Analyti-
cal X-ray Systems, Karlsruhe, Germany, 2000.
[50] Diamond, version 2.1d, K. Brandenburg, Crystal Impact GbR,
Bonn, 1996–2000.
J. L. Paillaud, M. Drillon, A. De Cian, J. Fischer, R. Weiss, G.
Villeneuve, Phys. Rev. Lett. 1991, 67, 244–247.
Y. Gao, Y. Chen, R. Li, Y. Bian, X. Li, J. Jiang, Chem. Eur. J.
2009, 15, 13241–52.
C. Janiak, J. Chem. Soc., Dalton Trans. 2000, 21, 3885–3896.
[43] C. R. Martinez, B. L. Iverson, Chem. Sci. 2012, 3, 2191–2201.
[44] S. Alvarez, Dalton Trans. 2013, 42, 8617–8636.
[45] G. A. Corker, B. Grant, N. J. Clecak, J. Electrochem. Soc. 1979,
126, 1339–1343.
[46] A. De Cian, M. Moussavi, J. Fischer, R. Weiss, Inorg. Chem.
1985, 24, 3162–3167.
[51] A. L. Speck, Acta Crystallogr., Sect. A Cryst. Struct. Commun.
1990, 46, C34.
Received: May 12, 2014
Published Online: July 23, 2014
Eur. J. Inorg. Chem. 2014, 4179–4185
4185
© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim