{P2V3W15}-Polyoxometalates Functionalized with Phthalocyaninato y and Yb Moieties

Article abstract of DOI:10.1021/acs.inorgchem.0c02257

A tris(alkoxo)pyridine-augmented Wells-Dawson polyoxometalate (nBu4N)6[WD-Py] (WD = P2V3W15O59(OCH2)3C, Py = C5H4N) was functionalized with phthalocyaninato metal moieties (MPc where M = Y or Yb and Pc = C32H16N8) to afford (nBu4N)4[HWD-Py(MPc)] compounds. High-resolution mass spectrometry was used to detect and identify the hybrid assembly. The magnetism studies reveal substantial differences between M = Yb (monomeric, single-ion paramagnetism) and M = Y (containing dimers, radical character). The results of electronic paramagnetic resonance spectroscopy, SQUID magnetometry, and magnetochemical calculations indicate the presence of intramolecular charge transfer from the MPc moiety to the polyoxometalate and of intermolecular charge transfer from the MPc moiety of one molecule to the polyoxometalate unit of another molecule. These compounds with identified VIV ions represent unique examples of transition-metal/lanthanide complex-POM hybrid compounds with nonphotoinduced charge transfer between electron donor and acceptor centers.

Full text of DOI:10.1021/acs.inorgchem.0c02257

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Article
{P2V3W15}‑Polyoxometalates Functionalized with Phthalocyaninato
Y and Yb Moieties
̈
Ricarda Putt, Piotr Kozłowski, Irina Werner, Jan Griebel, Sebastian Schmitz, Jonas Warneke,
and Kirill Yu. Monakhov*
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ABSTRACT: A tris(alkoxo)pyridine-augmented Wells−Dawson poly-
oxometalate (nBu4N)6[WD-Py] (WD = P2V3W15O59(OCH2)3C, Py =
C5H4N) was functionalized with phthalocyaninato metal moieties (MPc
where M = Y or Yb and Pc = C32H16N8) to afford (nBu4N)4[HWD-
Py(MPc)] compounds. High-resolution mass spectrometry was used to
detect and identify the hybrid assembly. The magnetism studies reveal
substantial differences between M = Yb (monomeric, single-ion
paramagnetism) and M = Y (containing dimers, radical character). The
results of electronic paramagnetic resonance spectroscopy, SQUID
magnetometry, and magnetochemical calculations indicate the presence
of intramolecular charge transfer from the MPc moiety to the
polyoxometalate and of intermolecular charge transfer from the MPc
moiety of one molecule to the polyoxometalate unit of another molecule.
These compounds with identified VIV ions represent unique examples of transition-metal/lanthanide complex-POM hybrid
compounds with nonphotoinduced charge transfer between electron donor and acceptor centers.
mechanism of electron charge transfer was described for
tris(alkoxo)-Csp3-derivatized POMs (a Wells−Dawson-type
[P2V3W15O62]9− or an Anderson-type POM) linked by a
bipyridine group to Re(I)-,21,22 Rh(III)-, and Ir(III)-com-
plexes23,24 or by an amido functionality to the Zn(II)
tetraphenylporphyrin complex.25 Advances in the area of
charge-transfer materials based on photosensitizer-POMs
hybrid assemblies are comprehensively discusssed in the
reviews by Santoni26 and Keyes.27
The above-mentioned findings came to our attention,
triggering the exploration of charge-transfer states in electron
donor−acceptor transition-metal/lanthanide complex-POM
hybrid compounds for their application and controlled
modification on electrode surfaces.28 Recent studies in the
field of molecular electronics have shown that POM-based
organic−inorganic hybrids can adsorb, for example, on gold
substrates as intact single molecules or in the form of self-
assembled monolayers (SAMs), and their electronic states can
be changed multiple times by electrical means.29−31 It is
therefore worth investigating POMs9,32−34 with their appealing
1. INTRODUCTION
Polyoxometalate (POM)-based organic−inorganic hybrid
compounds constitute a large part of stimuli-responsive
materials with promising applications in photo/electrocatalysis,
molecular magnetism, and energy storage.1−13 In particular,
their development is pursued due to high interest for
photoinduced charge transfer between transition-metal/
lanthanide complex units and POM. The effective attachment
of the former to the polyoxoanion unit can be effectively
realized via organic functional groups and linkages, which are
structurally exposed at the molecular periphery of POM
through well-established functionalization and postfunctional-
ization mechanisms.2,3,14−16 For instance, the formation of the
molecular heterometal metal-to-POM charge transfer (MPCT)
chromophore with a short-lived charge-separated state has
been observed in the compound K15NaP4W35O124{Re(CO)3}2·
37H2 O and its organic-solvent-soluble analog
(nBu4N)15[HP4W35O124]{Re(CO)3}2·0.3CH2Cl2, which con-
sist of a [Re(CO)3]+ unit bound directly to the lacunary
17
Wells−Dawson-type POM [α2-P2W17O61]10−
.
Photoinduced
long-lived charge-separated states were reported for the
photosensitizer-POM hybrids separated by a π-conjugated
spacer; examples include Ru(II)-bis(terpyridine)- or Ru(II)-
(tpy)2[PW11O39Ge]4− (Keggin-type),18,19 related cyclometa-
lated Ir(III) complexes-POMs (Keggin- or Wells−Dawson-
type),20 and noble metal-free bodipy fluorophores linked to Si-
or Sn-functionalized Keggin-type POMs.21 A through-space
Received: July 29, 2020
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electron transport characteristics as individual molecules and in
conjunction with transition-metal/lanthanide complexes for
molecule-based “More than Moore” information technology.35
The latest developments in the areas of POM-based charge-
transfer and POM-on-a-surface materials have prompted us to
elaborate (post)functionalization approaches16,36 toward the
formation of hybrid assembly where POM is connected
directly or via an organic linker to a metal ion ligated by the
redox-active phthalocyanine (Pc) ligand.37 Several of these
studies are ongoing to assess, on the one hand, the ability of
the target hybrid compounds to exhibit electron donor−
acceptor structures with ground-state charge transfer and to
unveil, on the other hand, their adsorption site preferences on
surfaces. In this regard, we could already showcase the direct
coordination of phthalocyaninato YbIII moieties onto the fully
oxidized, lacunary {V12O32}-type polyoxovanadate cage and
the generation of conductive SAMs made of these hybrid
complexes on gold surfaces.30
2. RESULTS AND DISCUSSION
2.1. Synthesis and Structure Characterization. The
pyridine-containing triol-ligand (HOCH2)3CC5H4N was
obtained by the reaction of 4-methylpyridine and an
aqueous formaldehyde solution at 100 °C in an autoclave,
according to the literature procedure.39 The reaction
o f ( H O C H 2 ) 3 C C 5 H 4 N w i t h t h e P O M
(nBu4N)5[H4P2V3W15O62]40 in a 1:1 ratio at 85 °C in
MeCN yielded a trisalkoxo-derivatized (nBu4N)6[WD-Py]
compound with the pyridine (Py) group at the molecular
periphery. The composition (including the number of nBu4N+
(= (C4H9)4N+) countercations) and the structural integrity of
(nBu4N)6[WD-Py] were determined by CHN elemental
analysis (see Table S1), 1H-, 31P-, and 51V-NMR and IR
spectroscopy (see Figure S1). The NMR spectra show one 51V
signal at −544 ppm and two 31P signals at −7.54 and −13.67
ppm, thus corroborating the absence of isomeric Wells−
Dawson-type species. Also, the 1H NMR spectra show
characteristic signals from the Py protons at δ = 8.61 and
7.51 ppm and from the six −CH2 protons of the trisalkoxo
ligand as a singlet at 5.61 ppm.
In the present study we focus on the connection of
phthalocyaninato YIII/YbIII (= M) moieties to POM via an
organic linker (Figure 1). We have succeeded in the formation
The follow-up room temperature (r.t.) reaction of
(nBu4N)6[WD-Py] with heteroleptic MPc(OAc)·2MeOH
(PcOAc = C34H19N8O2) in a 1:1 ratio in MeCN and the
workup with Et2O resulted in the trimetallic compounds
(nBu4N)4[HWD-Py(MPc)]·2Et2O, where the peripheral Py
group of the inorganic−organic (nBu4N)6[WD-Py] hybrid is
axially connected to the MPc moiety (Figure 1). Their
elemental composition analysis (Table S1) indicates the
presence of four nBu4N+ counterions, one proton at the
POM unit, and two Et2O units as co-crystallized solvent
molecules. Thermogravimetric data (Table S2) are in line with
elemental analysis. The compounds show thermal stability up
to ca. 220 °C in air and ca. 260 °C under nitrogen. The loss of
the diethyl ether solvent molecules was observed for each
analyzed compound.
Figure 1. Synthesis of the (nBu4N)4[HWD-Py(MPc)] compounds
with M = Y and Yb from the (nBu4N)6[WD-Py] and MPc(OAc)
precursors in MeCN. The H+ proton of the POM is not shown. r.t. =
room temperature. Color code: M = cyan, W = light blue, V = orange,
O = red, N = dark blue, P = purple, C = gray, H = white. See the SI
for details of synthesis, analytical characterization, and crystallographic
data.
The IR spectra of (nBu4N)5[WD], (nBu4N)6[WD-Py],
(nBu4N)4[HWD-Py(YPc)], and (nBu4N)4[HWD-Py(YbPc)]
are characterized by OPO, VO, WO, and
OWO vibrations in the 1100−700 cm−1 region, which
are typical for these Wells−Dawson-type POMs.40,41 No
significant difference between the IR spectra of the pyridine-
containing POMs [WD-Py]6− and [HWD-Py(MPc)]4− was
observed for the CNC vibration of the pyridine moiety,
which appears each as a weak absorption band at around 1595
cm−1. In addition, the [HWD-Py(MPc)]4− hybrids show
characteristic CH deformation vibrations at 1400−1100 cm−1
assigned to the Pc group.42 A more detailed comparison of the
IR spectra of the respective compounds can be found in Figure
S1.
of two hybrid assemblies (nBu4N)4[HP2V3W15O59(OCH2)3-
CC5H4N)(C32H16N8M)] (hereafter referred to as
(nBu4N)4[HWD-Py(MPc)]) that feature different magnetic
characteristics depending on the type of a phthalocyaninato
metal moiety (MPc+) attached at the periphery of the
organically modified Wells−Dawson-type polyoxoanion
[HP2V3W15O59(OCH2)3CC5H4N]5− (= {HWD-Py}5−) . The
synthesized compounds were characterized by various
methods, including electrospray ionization mass spectrometry
(ESI-MS), electron paramagnetic resonance (EPR) spectros-
copy, and magnetic susceptibility measurements combined
with magnetochemical calculations. This thus continues the
series of our works about the synthesis and properties of
POMs functionalized with phthalocyaninato lanthanide
moieties and about the behavior and performance of
tris(alkoxo)-ligated Wells−Dawson-type POM surfactants,
1H, 31P, and 51V NMR spectroscopy measurements (see
spectra in the SI) were performed only for (nBu4N)4[HWD-
Py(YPc)] with the diamagnetic character of yttrium.
1
Compared to the H NMR spectrum of (nBu4N)6[WD-Py],
no shift in peak position of −CH2 protons of the trisalkoxo
ligand in the title compound is observed. The protons of the
Py ring, however, are slightly shifted upfield, which points out
the changes in the coordination environment of Py with the
protons in the meta position being most affected (Δδ = ca.
0.1 ppm). The 31P (δ = −7.59 and −13.73 ppm) and 51V
NMR (δ = −543 ppm) spectra are characterized by a minor
such as {[HP2VV WVI15O59((OCH2)3CCH2OCH2C6H4I)]}5−,
3
in discrete solutions and on surfaces.38
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shift of the respective nuclei compared to those of
(nBu4N)6[WD-Py].
The presence of the phthalocyanine ligand in the title
compounds (nBu4N)4[HWD-Py(MPc)] with M = Y or Yb is
evident from their UV/vis spectra (see Figure S2), illustrating
characteristic absorption bands,42,43 i.e., a broad one at ca.
333 nm (B band) and an intense one at ca. 680 nm (Q band).
These bands are shifted by ca. 10 nm with respect to those of
the MPc(OAc)·2MeOH precursors. The absorption bands in
the wavelength range of 200−300 nm displayed by both
(nBu4N)4[HWD-Py(MPc)] compounds reflect, in particular,
ligand-to-metal charge transfer within the POM core (O to W/
V) and metal-to-ligand charge transfer between the Y/Yb and
Pc units.
The formation of the title coordination compounds is also
strongly supported by the signals with broad isotopic patterns
found in high-resolution ESI mass spectra (Figure 2, see also
Figures S3 and S4). Although we could observe signals
indicating a dissociation of the hybrid assembly in solution, the
most intense signals can be clearly attributed to the title
compounds. The small signals clearly visible between the
signals of POM-based ions {(nBu4N)[WD-Py(YPc)]}4−
(Figure 2a) point out the presence of a dimeric species
(with double mass and double charge). Thus, strong
intermolecular forces are necessary to hinder dimers of high
charge states from fragmentation in the gas phase. Corre-
sponding signals are, however, absent in the case of the
{(nBu4N)2[WD-Py(YbPc)]}3− ions (Figure 2b) or any other
detected combination of [WD-Py(YbPc)]5− with counterions.
Therefore, no dimers were found when M is Yb.
2.2. EPR Spectral Characteristics. The room temperature
EPR measurements of the title (nBu4N)4[HWD-Py(MPc)]
compounds in MeCN revealed no signal for the species with M
= Yb and a signal for M = Y (Figure 3). The latter was found to
match to a free delocalized organic radical44 with a g value of
2.0014 and a line width ΔBPP = 0.7 mT.
The monitoring of the room temperature EPR spectra of the
(nBu4N)4[HWD-Py(YPc)] compound at three different
concentrations (c = 5.0, 1.0, and 0.1 mM) in MeCN solution
revealed an intense signal at the highest concentration and a
very weak to no signal in low-concentrated solutions. At the
0.1 mM concentration in the measured 20 μL of solution the
number of spins is calculated to be 1015, which is still within a
detectable range of spin concentration according to the
literature 1014 spins.45 This might indicate that the detected
EPR signal enhancement takes place when the
(nBu4N)4[HWD-Py(YPc)] species get in closer proximity to
each other due to a higher concentrated solution. Thus, it
models to some extent a situation in the solid state where the
electron transfer is likely to occur between the neighboring
{HWD-Py(YPc)} units.
Figure 2. Measured and simulated isotopic patterns of fragments
[P2V3W15O59(OCH2)3CC5H4NC32H16N8Y((C4H9)4N)]4− (a) and
[P2V3W15O59-(OCH2)3CC5H4NC32H16N8Yb((C4H9)4N)2]3− (b) in
the negative ion-mode obtained from ESI-MS experiments with the
(nBu4N)4[HWD-Py(MPc)] compounds (M = Y and Yb) in MeCN.
See the SI for more details.
The solid-state EPR spectra of (nBu4N)4[HWD-Py(MPc)]
measured at 77 K showed in both cases (Figure 4), beside a
radical character of the compound with M = Y, an additional
hyperfine structure typical for isolated VO2+ ions with the
following values of g and A tensors: g⊥ = 1.9675, g∥ = 1.9125,
A⊥ = 61.5 G, and A∥ = 188.0 G. This hyperfine structure points
to the reduction of one of the VV ions in the POM to the
magnetically active VIV. The corresponding EPR measure-
ments of (nBu4N)4[HWD-Py(MPc)] at r.t. gave the same
results with lower intensity of VIV signals, though. The
precursor NaVO3, the only vanadium source in the synthesis
of (nBu4N)5[WD], is EPR silent.
The room temperature solid-state EPR spectra of the
MPc(OAc) complexes exhibit a radical signal for M = Y and no
signal for M = Yb. This is quite interesting since a similar
compound [YPc2]− containing YPc+ moiety has no radical
47
character,46 contrary to the neutral compound YPc2
containing YPc2+ moiety. The radical character of metal
monophthalocyanine complexes was first described by
Sugimoto et al. for MPc(dpm)2 complexes (dpm = tris-
(2,2,6,6-tetramethyl-3,5-heptanedionato; M = Lu, Y).48 The
authors observed characteristic EPR signals at r.t. in both the
solid state and solution, with a g value of 2.001. The EPR
spectra had similar shapes and g values for stable metal-free
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relevant for modeling the magnetism below room temperature.
The best fit of the experimental data was obtained with the
Hamiltonian:
H = −μ g (J Bx + J By) − μ g J Bz + DJ2
B
B
x
y
z
z
(1)
⊥
where J = (Jx, Jy, Jz) (J = 7/2) is a total angular momentum, B
is the magnetic field, and the parameters assume the
anisotropic g-factors of g⊥ = 1.063 and g∥ = 1.907 and the
anisotropy D/kB = 96.2 K. In Figure 5 the molar susceptibility
and magnetization of (nBu4N)4[HWD-Py(YbPc)] are shown
together with the theoretical curves. The details of the
modeling can be found in the SI.
Figure 3. Solution EPR spectra of (nBu4N)4[HWD-Py(MPc)] (c =
1.2 mM, MeCN) measured at r.t. at a frequency of 9.86 GHz,
modulation amplitude of 0.1 mT, and microwave power of 0.2 mW.
Color code: M = Yb, blue; M = Y, black; a simulated spectrum, red.
Figure 5. Molar susceptibility (B = 0.1 T) and magnetization (T = 2
K) for (nBu4N)4[HWD-Py(YbPc)] (circles) with theoretical fits
(solid lines).
For the YIII-containing POM-based hybrid assembly the
situation is more complicated (Figure 6). The appearance of
Figure 4. Solid-state EPR spectra of (nBu4N)4[HWD-Py(MPc)]
measured at 77 K at a frequency of 9.44 GHz, modulation amplitude
of 0.1 mT, microwave power of 0.2 mW, and T = 77 K. Color code:
M = Yb, blue; M = Y, black; a simulated spectrum, red.
[H(Pc−)] and lithiated phthalocyanine [Li(Pc−)] radicals,49,50
generated by a chemical or electrochemical oxidation.
Recently, Reecht et al. showed that in HPc radical the
dangling σ bond after N−H cleavage is filled by an electron
from the delocalized HOMO via intramolecular charge
transfer, providing for a delocalized radical state.51
2.3. Magnetic Susceptibility and Magnetochemical
Characteristics. Next, magnetic properties of the title
(nBu4N)4[HWD-Py(MPc)] compounds were assessed by
standard SQUID technique (0.1−5.0 T and 2.0−290 K) in
combination with effective Hamiltonian calculations. For M =
Yb the interpretation of the results is rather straightforward.
The lack of strong EPR signal at room temperature and the
expected +III oxidation state of Yb indicate that the magnetism
of this compound should originate mostly from the YbIII ion.
The EPR signal of rare earth ions can be obtained only in low
(liquid helium) temperatures.52 Like in the case of related
{[V12O32(Cl)](LnPc)n}n−5 compounds with n = 1 or 2 and Ln
= YbIII,30 we assume that only the ground multiplet with a total
angular momentum J = 7/2 arising from spin−orbit coupling is
Figure 6. Molar susceptibility (B = 0.1 T) and magnetization (T = 2
K) for (nBu4N)4[HWD-Py(YPc)] (circles) with theoretical fits (solid
lines).
the EPR signal with the increase of compound concentration
may indicate that the proximity of the molecules leads to some
change in the magnetism, caused for example by the electron
transfer. This conjecture is additionally confirmed by ESI mass
spectrometry showing the presence of dimers (see Figure 2).
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To account for the results of EPR and ESI-MS it is assumed
that some inter- and intramolecular electron transfer takes
place. For instance, an electron from Pc2− may jump to another
molecule. In this way two ions [HWD-Py(YPc)]3− and
[HWD-Py(YPc)]5− are formed. Each of these ions has now
one unpaired electron. The first one is likely located at Pc−; the
other, for example, may reduce VV to VIV, as supported by the
hyperfine structure in the solid-state EPR spectrum at low
temperature, or it may be delocalized over a bigger part of the
molecule. An intramolecular electron transfer apparently
occurs from Pc2− to POM, giving as a result a molecule with
two unpaired electrons. However, these mechanisms, even if
they coexist, are not able to explain the linear increase of χT
with temperature. Such a behavior suggests either strong
antiferromagnetic interaction (or anisotropy) or the presence
of temperature independent paramagnetism (TIP). Notably,
both mechanisms are observed in similar compounds with a
linear dependence of χT on temperature. For instance, in a
molecular compound [K(18-crown-6)(THF)2][(Cp″2La)2-
(μ−η6:η6-C6H6)]·THF containing LaII ions53 any of these
two mechanisms could be used to account for linear
dependence of χT on temperature. In [K(2.2.2-cryptand)]-
[Cp′3Y] containing a YII ion the linear dependence of χT on
temperature was attributed to TIP.54 Therefore, in the
magnetic modeling we assumed that a fraction p1 of the
molecules contains one unpaired electron and a fraction p2
contains two unpaired electrons possibly interacting with
strength K. In addition, we assume the presence of TIP. The
fitting of the susceptibility and magnetization leads to the
conclusion that to account for the linear increase of χT with
temperature the TIP contribution is indispensable. The
introduction of interaction between the unpaired electrons
located at one molecule can improve fitting of magnetization.
Figure 6 illustrates the results of two optimal fits. In fit (a),
p1 = 0.29 and p2 = 0.094 and the interaction is
antiferromagnetic (K/kB = 11.8 K). Susceptibility induced by
TIP is estimated to be equal to χTIP = 1.53 × 10−8 m3 mol−1.
The remaining fraction p3 = 0.62 of the molecules is not
magnetically active. This result can also be interpreted in this
way that the molecules with one unpaired electron are parts of
dimers in which an electron transfer took place, whereas those
with two unpaired electrons appear as a result of intra-
molecular electron transfer. In fit (b), p1 = 0.0006 and p2 =
0.13 and the interaction is ferromagnetic (K/kB = −217 K).
structure and a radical character for M = Y and a single-ion
paramagnetic character for M = Yb. Femtosecond transient
absorption spectroscopy and pulse radiolysis experiments
accompanied by quantum mechanical calculations are
currently in progress to gain deeper insights into the
mechanism of the observed intra- and intermolecular electron
charge transfer from MPc to the {V3} triad of POM (VV →
VIV) and into underlying changes in the electronic structure.
The findings described herein are especially of high interest for
studies of radical spin effects on electron transport character-
istics of POM compounds, their molecular ordering, and
electron communication on surfaces.
ASSOCIATED CONTENT
■
sı
* Supporting Information
The Supporting Information is available free of charge at
https://pubs.acs.org/doi/10.1021/acs.inorgchem.0c02257.
Details of synthesis, analytical characterization, and
magnetism (PDF)
AUTHOR INFORMATION
■
Corresponding Author
Kirill Yu. Monakhov − Leibniz Institute of Surface
Engineering (IOM), 04318 Leipzig, Germany; orcid.org/
0000-0002-1013-0680; Email: kirill.monakhov@iom-
leipzig.de
Authors
Ricarda Putt − Institute of Inorganic Chemistry, RWTH
̈
Aachen University, 52074 Aachen, Germany
Piotr Kozłowski − Faculty of Physics, Adam Mickiewicz
University in Poznań, 61-614 Poznań, Poland
Irina Werner − Leibniz Institute of Surface Engineering
(IOM), 04318 Leipzig, Germany
Jan Griebel − Leibniz Institute of Surface Engineering (IOM),
04318 Leipzig, Germany
Sebastian Schmitz − Leibniz Institute of Surface Engineering
(IOM), 04318 Leipzig, Germany
Jonas Warneke − Leibniz Institute of Surface Engineering
(IOM), 04318 Leipzig, Germany; Wilhelm-Ostwald-Institute
for Physical and Theoretical Chemistry, Leipzig University,
04103 Leipzig, Germany
Susceptibility induced by TIP is estimated to be equal to χTIP
=
Complete contact information is available at:
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2.01 × 10−8 m3 mol−1. The remaining fraction p3 = 0.87 of the
molecules is not magnetically active. Both fits reproduce a
general character of the susceptibility and magnetization curves
depicted in Figure 6 but are far from ideal. It strongly suggests
that an improved magnetochemical model55−57 needs to be
further fine-tuned for such intricate electronic situations
described herein, work that is currently in progress. The
determination of the precise source of TIP is also needed.
More details on modeling the magnetism of (nBu4N)4[HWD-
Py(YPc)] can be found in the SI.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
This work was supported by the Emmy Noether program and
Individual Research Grant (project no. 432224404) of the
Deutsche Forschungsgemeinschaft (DFG). Computational
time from the ZIH Dresden is gratefully acknowledged.
Some model Hamiltonian calculations were carried out at
3. CONCLUSIONS
́
The Wells−Dawson P2V3W15-type POM with the structurally
exposed tris(alkoxo)pyridine functionality provided a con-
nection to phthalocyaninato Y and Yb moieties. The
spectroscopic and magnetic measurements indicated that the
interaction of MPc units with the fully oxidized POM-based
organic−inorganic hybrid gives rise to a donor−acceptor
the Poznan Supercomputing and Networking Centre in
Poland. J.W. acknowledges a Freigeist Fellowship of the
Volkswagen Foundation. The authors thank Prof. Bernd Abel
(Leipzig University, IOM) for access to an LTQ Orbitrap XL
and Dr. Jan van Leusen (RWTH Aachen University) for
helpful discussions on magnetism.
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̈
(19) Luo, Y.; Wachtler, M.; Barthelmes, K.; Winter, A.; Schubert, U.
S.; Dietzek, B. Coexistence of distinct intramolecular electron transfer
pathways in polyoxometalate based molecular triads. Phys. Chem.
Chem. Phys. 2018, 20, 11740−11748.
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