peculiarities of C60- coordination to cobalt(II) octaethylporphyrin in ionic multicomponent complexes: Observation of the reversible formation of Co-C(C60-) coordination bonds

Article abstract of DOI:10.1002/chem.200600132

Ionic multicomponent complexes containing the C₆₀ anion, cobalt(II) octaethylporphyrin (OEP), and the noncoordinating tetramethylphosphonium cation (TMP⁺), [(TMP⁺){Co ¹¹OEP(C₆₀^-)}(C₆H₅CN) _x-(C₆H₄Cl₂)_1-x] (x?0.75) (1), or the coordinating cation of N-methyldiazabicyclooctane (MDABCO⁺), [{(MDABCO⁺)Co^IIOEP(C ₆₀^-)}(C₆H₅CN)_x(C ₆H₄Cl₂)_1-x (x?0.67) (2), were obtained. Diamagnetic o-bonded {Co^IIOEP(C₆₀^-)) units in 1 have the Co...C(C₆₀) distance of 2.268(1) A at 100 K and are stable up to 290 K. Both MDABCO⁺ and C ₆₀^- coordinate to Co^IIOEP in 2. In this case, a noticeably longer Co...C(C₆₀^-) distance of 2.508(4) A was observed at 100 K. As a result, the unprecedented reversible formation of the Co-C(C₆₀^-) coordination σ bond is realized in 2 and is accompanied by a transition from a paramagnetic to a diamagnetic state in the 50-250 K range. It was shown, for the first time, that the Co...C distance of about 2.51 A is a boundary distance below which the Co-C(C₆₁^-) coordination bond is formed.

Full text of DOI:10.1002/chem.200600132

FULL PAPER
DOI: 10.1002/chem.200600132
Cꢀ
Peculiarities of C60 Coordination to Cobalt(ii) Octaethylporphyrin in Ionic
Multicomponent Complexes: Observation of the Reversible Formation of
ꢀ
ꢀ
Co C
A
Dmitri V. Konarev,*[a, b] Salavat S. Khasanov,[a, c] Akihiro Otsuka,[d] Gunzi Saito,*[a] and
Rimma N. Lyubovskaya[b]
Abstract: Ionic multicomponent com-
plexes containing the C60 anion, co-
balt(ii) octaethylporphyrin (OEP), and
{CoIIOEP
G
2.508(4) Š was observed at 100 K. As a
ꢀ
Co···C
A
result, the unprecedented reversible
(C60ꢀ) coordina-
ꢀ
100 K and are stable up to 290 K. Both
formation of the Co C
the
phosphonium
[(TMP+){CoIIOEP
noncoordinating
tetramethyl-
(TMP+),
MDABCO+ and C60 coordinate to
tion s bond is realized in 2 and is ac-
companied by a transition from a para-
magnetic to a diamagnetic state in the
50–250 K range. It was shown, for the
first time, that the Co···C distance of
about 2.51 Š is a boundary distance
ꢀ
cation
CoIIOEP in 2. In this case, a noticeably
A
N
N
longer
ACHTREUNG
Keywords: crystal engineering
donor–acceptor
fullerenes
A
N
below which the Co C
tion bond is formed.
A
A
G
]
(xffi0.67) (2),
solid-state structures
were obtained. Diamagnetic s-bonded
Introduction
with metal octaethyl- and tetraarylporphyrins.[3–7] For some
of these cocrystals, weak metal–carbon(fullerene) bonding
was found. For example, cobalt(ii) octaethylporphyrin
(CoIIOEP), cobalt(ii) tetraphenylporphyrin (CoIITPP), and
Fullerene compounds with porphyrins and metalloporphy-
rins attract special attention because of their possible use as
ACHTREUNG
precursors for photovoltaic materials and models of artificial
iron
M···C
2.69–2.70 Š, respectively.[3–6] These contacts are notice
ACHTREUNG
photosynthesis.[1,2] Fullerenes were shown to cocrystallize
AHCTREUNG
ACHTREUNG
shorter than the sum of the van der Waals radii of metal
(M) and C atoms (>3.1 Š), but are essentially longer than
[a] Dr. D. V. Konarev, Dr. S. S. Khasanov, Prof. G. Saito
Division of Chemistry, Graduate School of Science
Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
Fax : (+81)75-753-40-35
ꢀ
the length of a strong M C bond, for example, in alkylco-
A
E-mail: konarev@icp.ac.ru
the fullerene molecules in the complexes with metal octae-
thylporphyrins, and allows the molecular structures of some
saito@kuchem.kyoto-u.ac.jp
[b] Dr. D. V. Konarev, Prof. R. N. Lyubovskaya
Institute of Problems of Chemical Physics RAS
Chernogolovka, Moscow region 142432 (Russia)
Fax : (+7)496-515-54-20
fullerene derivatives and endometallofullerenes to be stud-
C
ied.[3,9,10] Essentially stronger bonding between CoIITPP and
fullerene anions was observed in ionic multicomponent com-
+
plexes, such as [{CrI
(C6H6)2
}
G
C
[c] Dr. S. S. Khasanov
Institute of Solid State Physics RAS
Chernogolovka, Moscow region 142432 (Russia)
(Cr
A
G
C60(CN)2) with the lengths of the Co···C(fullereneꢀ) contacts
being 2.28–2.32 Š. The coordination is realized by s-type
bonding, and most probably involves both electrons from
the CoIITPP dz2 orbital and the LUMO of C60ꢀ. The result-
ing {CoIITPP(fullereneꢀ)} coordination units are diamagnet-
[d] Dr. A. Otsuka
Research Center for Low Temperature and Materials Sciences
Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
Supporting information (IR and EPR data for complexes 1 and 2;
Table S1 and Figures S1–S4) for this article is available on the WWW
under http://www.chemeurj.org/ or from the author.
ic.[11] The Co···C(C60ꢀ) s bonds are still relatively weak com-
U
Chem. Eur. J. 2006, 12, 5225 – 5230
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
5225

ꢀ
pared with the strong Co C bonds in alkylcobalamins, and
their dissociation is possible. The changes in the degree of
creased the reduction time to less than one hour. NaI and
NaCl did not dissolve in the solvents used and precipitated,
thus allowing the reaction of cationic metathesis to be real-
ized during the fullerene reduction. CH3CH2SNa and
MDABCOI or TMPCl were also barely soluble in these sol-
vents, and the excess of these salts was separated from the
ꢀ
Co C bonding can be monitored by using electron paramag-
netic resonance (EPR) and superconducting quantum inter-
ference device (SQUID) techniques because two paramag-
netic species are formed as a result of the dissociation. Com-
plexes showing such dissociation can be interesting not only
because of the reversible changes in their magnetic, con-
ducting, and optical properties, but also because they can
help to solve some fundamental problems of coordination
and materials chemistries, one of which is how coordination
Cꢀ
resulting solution by using filtration. (R+)
ACHTREUNG
soluble in the solvents used here and could be further crys-
tallized by the diffusion of hexane. The crystallization of
these salts in the presence of CoIIOEP afforded multicom-
ponent complexes 1 and 2 whose compositions were deter-
mined from elemental analysis and verified by using X-ray
diffraction on single crystals.
bonds are formed and what limiting distances exist for such
+
C
bonding.
tetrakis(dimethylamino)eth
s-bonded diamagnetic {CoIITPP
In
[(TDAE
)
{CoIITPP
(C60ꢀ)}]
(TDAE=
G
Both complexes have similar crystal structures at 100 K.
The main building blocks of 1 and 2 are shown in Figure 1.
AHCTREUNG
above 190 K and about 20% of the units dissociate at 290 K
Cꢀ
to form nonbonded paramagnetic CoIITPP and C60 species.
As a result, the magnetic moment of the complex increases
and the EPR signal broadens and shifts to larger g-factor
values.[12] However, the crystal structure of this complex is
unknown and therefore prevents a study of the structural as-
pects of such reversible coordination. An important task of
materials chemistry is the development of new methods for
modifying the physical properties of compounds, and in this
work we will demonstrate how a simple variation of the
countercations can drastically affect the properties of the re-
sulting complexes.
In the present work, the crystals of two ionic multicompo-
nent
(C6H4Cl2)1-x
(C60ꢀ)}
complexes,
[(TMP+)
N
U
N
G
]
G
(C6H5CN)x
A
methylphosphonium cation and MDABCO+ =cation of N-
methyldiazobicyclooctane), were obtained by means of dif-
fusion. This has allowed us, for the first time, to study the
molecular structures and properties of the new and unusual
Figure 1. Molecular structures of the s-bonded {CoIIOEP
(C60ꢀ)} unit in 1
AHCTREUNG
ꢀ
the major orientation for disordered C60 is shown for 1 and 2 and one
orientation of disordered MDABCO+ is shown for 2.
coordination {Co OEP
reversible formation of the Co C
(C60ꢀ)} assemblies and observe the
II
ꢀ
ꢀ
The cations and the fullerene anions are positioned on op-
posite sides of the CoIIOEP macrocycle. All eight ethyl
groups of CoIIOEP are directed towards the fullerene to
form a bowl-shaped conformation, which corresponds well
with the spherical shape of C60. There is one short Co···C-
Results and Discussion
The selective reduction of C60 by propanethiol in the pres-
ence of potassium carbonate has been carried out in polar
DMSO and a DMSO/benzene mixture up to the ꢀ2 and ꢀ1
charged states of C60, respectively.[13] Recently, commercially
A
tion of a s bond between CoIIOEP and C60ꢀ. The distances
between the Co atom and the carbon atoms closest to the
coordinated carbon are longer (2.956–3.061 Š). The Co
atom is shifted by 0.105(1) Š from the mean plane of the
four nitrogen atoms towards the fullerene (the porphyrin
macrocycle has a slightly concave conformation with a root
mean square (rms) deviation of 0.090 Š). Previously descri-
bed s-bonded {CoIITPP(fullereneꢀ)} anions have close
available CH3CH2SNa has been used for the selective pro-
2ꢀ
duction of C60 in acetonitrile.[14] Stirring a so
N
in
a less-polar o-dichlorobenzene/benzonitrile (C6H4Cl2/
C6H5CN, 19:1) mixture with a tenfold molar excess of
CH3CH2SNa at 608C provided selective reduction of C60 to
C60 radical anions according to the near-IR (NIR) spec-
Co···C
(C60ꢀ) distances of 2.28–2.32 Š and the Co atom devi-
C
Cꢀ
trum of the solution. However, the reduction takes a rela-
tively long time (more than 6 h), and because of the poor
solubility of the sodium salt of C60, it partially precipitates
from solution. The addition of a fivefold molar excess of
ates from the plane of the porphyrin macrocycle by
0.091(3) Š to 0.113(1) Š.[11] The TMP+ cation is located ex-
actly above the Co atom (Figure 1, left). The shortest Co···P
distance is 4.069 Š.
DABCO is a strongly coordinating bidentate ligand. The
addition of one equivalent of CH3I to DABCO affords a co-
any organic (R+)
A
used MDABCOI and TMPCl) in the reaction mixture de-
5226
www.chemeurj.org
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2006, 12, 5225 – 5230

Ionic Multicomponent Complexes
FULL PAPER
ordinating monodentate MDABCO+ cation. The building
anions.[15] A broad asymmetric signal with approximate g
factors of 2.31 and 2.29 (DHffi60 and 40 mT, respectively, at
4 K) was attributed to CoIIOEP. The estimated integral in-
tensities of both signals did not exceed 2% of the total
block of 2 is similar to that of 1. However, MDABCO+ ad-
II
ꢀ
ditionally coordinates to Co OEP (the Co N distance is
2.340(3) Š; Figure 1, right). This coordination weakens the
(C60ꢀ) bonding and the shortest Co···C distance in 2
amount of CoIIOEP and C60 . Therefore, 1 is EPR silent in
Cꢀ
Co···C
noticeably elongates to 2.508(4) Š at 100 K. The Co atom is
the 4–290 K range, justifying the formation of diamagnetic
ꢀ
more strongly bound to MDABCO+ than to C60 and, as a
s-bonded {CoIIOEP(C60ꢀ)} units and in accordance with X-
A
result, is slightly shifted (0.042(1) Š) from the mean plane
of the four porphyrin nitrogen atoms towards the nitrogen
atom from MDABCO+. The porphyrin macrocycle has the
same concave conformation as in 1 with rms=0.102 Š. The
C60 anions are disordered in both 1 and 2 (see the Experi-
mental Section) owing to their rotation about the coordina-
ray diffraction data. Weak EPR signals observed for 1 at
low temperatures can be attributed to a small amount of
Cꢀ
EPR-active isolated CoIIOEP and C60 species retained in
the sample in the nonbonded state. Similar residual EPR
signals were observed in ionic fullerene complexes after
ꢀ
Cꢀ
Cꢀ
C60 and C70 dimerization.[16]
tion Co C
(C60ꢀ) bond. The coordinated carbon atoms under
Two weak EPR signals were also observed for 2 in the 4–
50 K range. At 4 K the signal with g=1.9996 and DH=
ꢀ
such disorder are ordered in both complexes in a way that
Cꢀ
allows the Co···C
(C60ꢀ) distances to be determined. Weaker
0.44 mT was attributed to isolated nonbonded C60 (this
ꢀ
(C60ꢀ) bonding in 2 provides a larger degree of C60
signal also noticeably broadens with the temperature in-
crease to give DH=4.64 mT at 120 K), and an asymmetric
signal with g1 =2.3774 and g2 =2.3011 (DH=7.5 and
14.5 mT) was attributed to CoIIOEP coordinated to
MDABCO+. The total integral intensity of both signals was
ꢀ
Co C
ꢀ
disorder. Indeed, there are three orientations of C60 in 2
with 0.4:0.3:0.3 occupancies and only two such orientations
in 1 with 0.75:0.25 occupancies.
The fullerenes form zigzag one-dimensional chains along
the a axis (Figure 2). The zigzag arrangement of the fuller-
enes produces cavities for small cations, which protrude into
the fullerene chains. The center-to-center distances between
ꢀ
less than 2% of the total amount of C60 and CoIIOEP, and
both signals could not be resolved above 140 K. The EPR
data verify the diamagnetism of the {(MDABCO+)-
ꢀ
C60 in the chains are 10.026 Š in 1 and 10.297Š in 2. The
A
N
Cꢀ
the CoIIOEP and C60 spins pairing on formation of a Co
ꢀ
ꢀ
van der Waals interfullerene C C contacts of 3.195–3.562 Š
are observed only in 1, whereas in 2 the larger MDABCO+
C
(C60ꢀ) coordination s bond. The broad signal reversibly
A
ꢀ
cations force the C60 units apart from each other.
grows above 50 K (Figure 3) and above 250 K its integral in-
1
tensity corresponds to the contribution of about two = spins
2
1
Cꢀ
per formula unit (both CoIIOEP and C60 have
=
spin
2
states). The signal has a g factor of 2.1188 (DH=52 mT) at
room temperature, which is between those values character-
istic of CoIIOEP (the asymmetric signal with g1 =2.37, g2 =
Cꢀ
2.03 for five-coordinated CoIIOEP)[17] and C60 (g=1.9996–
2.0000),[15] thus indicating strong exchange coupling between
Figure 2. View of the crystal structure of 1 along the a axis and the fuller-
ꢀ
ene zigzag chains. Only the major orientation of disordered C60 and the
dichlorobenzene molecules is shown. Complex 2 has similar crystal pack-
ing.
Figure 3. Temperature dependence of the integral intensity of the EPR
Compound 1 is EPR silent at 290 K, whereas at low tem-
peratures (4–120 K) two weak EPR signals are resolved.
The signal with a g factor of 1.9996 and a line half-width
(DH) of 0.48 mT at 4 K was attributed to isolated nonbond-
signal in 2 (red curve) attributed to a resonating signal from nonbonded
Cꢀ
paramagnetic CoIIOEP and C60 species. The behavior is reversible. The
blue dashed line shows the expected integral intensity of the EPR signal
for noninteracting paramagnetic centers. The blue arrow indicates the
temperature at which the crystal structure of 2 was determined, and the
corresponding values of both the observed and expected integral intensi-
ties of the EPR signal (C is the Curie constant, T is temperature).
Cꢀ
ed C60 . This signal noticeably broadens with an increase of
Cꢀ
temperature, which is characteristic of C60
radical
Chem. Eur. J. 2006, 12, 5225 – 5230
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
5227

D. V. Konarev, G. Saito et al.
(C60ꢀ) coor-
Conclusion
ꢀ
these paramagnetic species. Therefore, the Co C
dination s bond observed at low temperatures completely
dissociates above 250 K to produce two nonbonded para-
The preparation of new, ionic, multicomponent complexes 1
and 2 has allowed, for the first time, the study of the coordi-
Cꢀ
magnetic {(MDABCO+)CoIIOEP} and C60 species. This is
ꢀ
ꢀ
the first example of such reversible formation of the Co C-
nation of C60 anions to cobalt(ii) octaethylporphyrin. Non-
A
coordinating TMP+ cations provide the formation of stable
magnetic to a diamagnetic state.
s-bonded diamagnetic {CoIIOEP(C60ꢀ)} units, which are sim-
E
The IR spectra of 1 and 2 indicate the ionic ground state
of the complexes (see the Experimental Section). The F1u(4)
mode of C60, which is sensitive to charge transfer (CT) to
the fullerene molecule,[18] is shifted from n˜ =1429 cmꢀ1 to
1387, 1395, and 1398 cmꢀ1 (split band) in 1 and to 1378,
1387, and 1394 cmꢀ1 (split band) in 2. The difference in the
bonding in 1 and 2 at 290 K is seen in their NIR spectra
ilar to the previously described {CoIITPP(C60ꢀ)} units.[11] In
U
contrast to TMP+, MDABCO+ cations additionally coordi-
II
ꢀ
nate to Co OEP to destabilize the Co C
(C60ꢀ) coordination
bond. This bond reversibly dissociates in the 50–250 K range
and this dissociation is accompanied by a diamagnetic–para-
magnetic transition. TMP+ and MDABCO+ cations only
differ in their coordination ability, which results in different
Cꢀ
II
(C60ꢀ) bonding, and different magnetic
ꢀ
(Figure 4). The bands of the nonbonded C60 radical anion
degrees of Co OEP
and optical properties of 1 and 2. Therefore, these parame-
ters can be controlled in the multicomponent complexes by
choosing the cation type. The crystal structure of 2 was de-
ꢀ
termined at 100 K, when the Co C
(C60ꢀ) coordination s
G
bond with a length of 2.508(4) Š is formed (according to
EPR, the contribution of a diamagnetic bonded state in
{(MDABCO+)
A
N
100 K (Figure 3)). Thus, the Co···C distance of about 2.51 Š
ꢀ
ꢀ
can be considered as a limiting length for the Co C
(C60
)
coordination s bond. This bond length is longer than the
strong Co C bond in alkylcobalamins (1.99–2.03 Š ) and
[8]
ꢀ
ꢀ
the Co C bond in 1 (2.27Š).
Figure 4. UV-visible-NIR spectra of a) 1, b) 2, and c) pristine CoIIOEP in
KBr pellets.
Experimental Section
Materials: Cobalt(ii) octaethylporphyrin (CoIIOEP), diazabicyclooctane
(DABCO), sodium ethanethiolate (CH3CH2SNa), tetramethylphosphoni-
um chloride (TMPCl), and methyl iodide (CH3I) were purchased from
Aldrich, and C60 (99.98% purity) was purchased from MTR Ltd. The sol-
vents were purified in an argon atmosphere. o-Dichlorobenzene
(C6H4Cl2) was distilled over CaH2, P2O5, and K2CO3 under reduced pres-
sure, benzonitrile (C6H5CN) was distilled over Na under reduced pres-
sure, and hexane and benzene were distilled over Na/benzophenone. The
solvents were degassed and stored in a glove box. All manipulations for
the synthesis of air-sensitive 1 and 2 were carried out in a MBraun 150B-
G glove box with a controlled atmosphere and with an H2O and O2 con-
tent of less than 1 ppm. The crystals were stored in a glove box and were
sealed in 2 mm quarts tubes for EPR measurements under 10ꢀ5 torr. KBr
pellets for the IR and UV-visible-NIR measurements were prepared in a
glove box.
are mainly observed in the spectrum of 2 at l=933 and
1078 nm (these two bands are characteristic of C60 and
Cꢀ
were previously observed in salts and ionic complexes con-
Cꢀ
taining C60 radical ions[15]). On the contrary, in the spec-
Cꢀ
trum of 1 the band of C60 at l=1086 nm decreases in in-
tensity and a strong, broad band manifests itself at 1277 nm.
The first band was attributed to the intramolecular transi-
ꢀ
tions in the bonded C60 anion, whereas the second band
can be attributed to CT between CoIIOEP and C60ꢀ. Previ-
ously, similar CT bands with slightly different positions were
observed in multicomponent complexes containing s-
bonded diamagnetic {CoIITPP(fullereneꢀ)} units.[11,19] Coor-
dination noticeably shifts the positions of the Soret and the
Q bands of CoIIOEP. Pristine CoIIOEP has bands at l=394,
531, and 560 nm and these bands appear at l=398, 523, and
552 nm and at l=402, 522, and 549 nm in the spectra of 1
and 2, respectively. Therefore, the Soret band is redshifted
by up to 8 nm and the Q bands are blueshifted by 8 to
11 nm.
General: UV-visible-NIR spectra were measured on a Shimadzu-3100
spectrometer in the l=240–2600 nm range. FTIR spectra were measured
by using KBr pellets with a Perkin–Elmer 1000 Series spectrometer (n˜ =
400–7800 cmꢀ1). EPR spectra were recorded from 290 K down to 4 K and
back from 4 K up to 290 K with a JEOL JES-TE 200 X-band ESR spec-
trometer equipped with a JEOL ES-CT470 cryostat. The integral intensi-
ty of the signals from a weighed amount of 1 and 2 was calibrated by the
comparison with the integral intensity of the EPR signal from a weighed
amount of CuSO4·5H2O.
Synthesis: N-Methyldiazabicyclooctane iodide (MDABCOI) was ob-
tained by the dropwise addition of one molar equivalent of CH3I
(1.11 mL, 0.0178 mol) to DABCO (2 g, 0.0178 mol) dissolved in hexane
(60 mL) while stirring. A white crystalline precipitate of MDABCOI
formed during the addition. After 1 h the precipitate was filtered off,
washed with hexane (100 mL), and dried under vacuum over 8 h.
5228
www.chemeurj.org
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2006, 12, 5225 – 5230

Ionic Multicomponent Complexes
MDABCOI (4.07g, 90%) was ob-
FULL PAPER
Table 1. X-ray diffraction data for 1 and 2.
tained with
analysis.
a satisfactory elemental
1
2
structural formula
empirical formula
A
N
U
A
U
The crystals of 1 were obtained by the
following procedure: C60 (25 mg,
0.035 mmol), a 10-fold molar excess of
CH3CH2SNa (30 mg, 0.35 mmol), and
G
E
E
N
C106.75H60.75N4.75Cl0.5PCo
1517.48
black, prisms
0.50”0.30”0.20
orthorhombic
P212121
14.9130(5)
17.7736(6)
25.8503(8)
6851.8(4)
4
1.471
0.3570.338
3140
0.84/0.93
100 (2)
65.2
62958
24435
1601
1640
19220
0.0496
0.1162
0.0683
C109.68H63.67N6.67Cl0.66Co
1557.15
black, prisms
0.40”0.20”0.20
orthorhombic
Pna21
26.1193(9)
17.9102(6)
14.9018(5)
6971.1(4)
Mr [gmolꢀ1
]
color, shape
size [mm]
system
space group
a [Š]
a
5-fold molar excess of TMPCl
(22 mg, 0.175 mmol) were stirred in a
C6H4Cl2/C6H5CN (19:1; 20 mL) mix-
ture for 1 h at 608C. C6H5CN was
added to increase the solubility of
CH3CH2SNa and TMPCl, which are
very poorly soluble in pure C6H4Cl2.
During stirring, the solution changed
from violet, characteristic of neutral
C60, to red-brown. After cooling the
solution down to room temperature
and filtering it, the NIR spectrum of
the solution was measured to indicate
the selective reduction of C60 to the
monoanionic state. CoIIOEP (21 mg,
0.035 mmol) was dissolved in the solu-
tion at 608C for 1 h. The resulting so-
b [Š]
c [Š]
V [Š3]
Z
4
1calcd [gcmꢀ3
]
1.484
m [mmꢀ1
]
F
A
3227
max/min transmission
T [K]
0.88/0.93
100 (2)
56.56
43541
13559
1652
max 2q [8]
reflns measured
unique reflns
parameters
restraints
reflns [Fo >2sFo]
R1 [Fo >2sFo]
wR2 (all data)[a]
a
lution was cooled, filtered into a glass
9918
tube (1.8 cm diameter, 50 mL volume)
with a ground glass plug, and hexane
(20 mL) was layered over the solution.
The diffusion was carried out over
2 months to give crystals of 1 on the
wall of the tube. The solvent was deca-
nted from the crystals and they were
washed with hexane to give black
prisms with a characteristic blue luster
(up to 0.3”0.5”1 mm3 in size) in 20%
yield.
10783
0.0769
0.1690
0.1060
2219.48
1.070
b
1.2556
1.040
1.018
GOF
restr. GOF
2
1.063
2
[a] w=1/[s
2(Fo )+(aP)2 +bP], P=[max
G
A similar procedure was used for the
preparation of 2. After cooling the so
lution with dissolved CoIIOEP, a
N
lected by f and w scans with a 0.38 frame width and 30 s exposure time
per frame. The data were integrated, scaled, sorted, and averaged by
using the Bruker AXS software package.[22] The structure was solved by
direct methods using SHELXTL version 6.12.[22] The structure was re-
fined by using full-matrix least-squares methods against F2. No absorp-
tion corrections were performed for either complex. Non-hydrogen
atoms were refined in the anisotropic approximation. Positions of the hy-
drogen atoms were calculated geometrically. Subsequently, the positions
of the H atoms were refined by the “riding” model with Uiso =1.2Ueq of
polycrystalline precipitate of 2 formed over several hours. The small crys-
tals suitable for X-ray diffraction measurements were obtained by the
diffusion of a solution of CoIIOEP (16 mg, 0.027mmol) in hexane/ben-
zene (4:1, 25 mL) into a C6H4Cl2/C6H5CN solution (19:1; 20 mL) ob-
tained from the reduction of C60 (25 mg, 0.035 mmol) by a 10-fold molar
excess of CH3CH3SNa (30 mg, 0.35 mmol) in the presence of a 5-fold
molar excess of MDABCOI (44.5 mg, 0.175 mmol). After 2 months, small
crystals of 2 formed on the wall of the tube. The solvent was decanted
from the crystals, which were washed with hexane to give small parallele-
pipeds with a characteristic blue luster (up to 0.2”0.2”0.4 mm3 in size)
in 30% yield.
the connected non-hydrogen atom or as ideal CH3 groups with Uiso
=
1.5Ueq. The details of the crystal-structure analysis are given in Table 1.
Molecule disorder in 1 and 2: CoIIOEP and TMP+ are ordered in 1 at
ꢀ
{CoIIOEP
U
U
U
100 K. The C60 anions are disordered between two orientations
A
ꢀ
(0.75:0.25 occupancies) related to the rotation of C60 by ꢁ158 about the
sis calcd (%) for C106.75H60.75N4.75O2Cl0.5PCo (1549.48): C 82.65, H 3.95, N
4.32, O 2.08, Cl 1.15, P 2.01; found: C 81.34, H 3.51, N 3.56, Cl 1.12, P
2.31.
Co C
(C60ꢀ) coordination bond and, correspondingly, the axis passing
ꢀ
through the coordinated carbon atom and the carbon atom located oppo-
site the coordinated carbon. Thus, these two carbon atoms are ordered in
A
(C60ꢀ)}
A
G
1 in such a way that allows the Co···C
(C60ꢀ) distance to be determined.
G
analysis calcd (%) for C109.68H63.67N6.67O2Cl0.66Co (1589.15): C 82.92, H
4.00, N 5.88, O 2.01, Cl 1.48; found: C 82.22, H 3.92, N 5.72, Cl 1.74.
Solvent C6H5CN and C6H4Cl2 molecules share one position with 0.75:0.25
occupancies. Both molecules are disordered between two orientations
and have 0.50:0.25 and 0.20:0.05 occupancies, respectively. In 2 only
The compositions of 1 and 2 were determined from the elemental analy-
sis, and were verified by X-ray diffraction analysis on a single crystal.
The difference between the value calculated by using the equation
[100ꢀ(C, H, N, Cl, P,)]% and the calculated content of Co for air-sensi-
tive 1 and 2 indicates the addition of oxygen to the complex in the course
of the analysis (about one O2 molecule per formula unit). The addition
of O2 to ionic C60 complexes during the elemental analysis has also been
reported elsewhere.[16,20,21]
ꢀ
CoIIOEP is ordered at 100 K. The C60 disorder has been approximated
by three restrained molecules of fullerene C60 with one collective carbon
atom coordinating to the Co atom of CoIIOEP, the disorder being a dis-
tribution in three orientations with 0.4:0.3:0.3 occupancies given by the
ꢀ
ꢀ
rotation about the Co C
(C60
)
coordination bond. As
a
result, the
ꢀ
carbon atom of C60 coordinated to CoIIOEP in 2 is ordered in such a
ꢀ
way that also allows the Co···C
(C60
)
distance to be determined.
between two orientations
Crystal-structure determination: X-ray diffraction data for 1 and 2 were
collected at 100(2) K by using a Bruker Nonius X8 Apex diffractometer
with CCD area detector (MoKa radiation, l=0.71073 Š) equipped with
an Oxford Cryosystems nitrogen gas-flow apparatus. The data were col-
MDABCO+ cations are disordered in
2
(0.56:0.44 occupancy) linked by the 208 rotation about the axis passing
through two nitrogen atoms of MDABCO+. C6H5CN and C6H4Cl2 sol-
vent molecules also share one position with 0.67:0.33 occupancies. Both
Chem. Eur. J. 2006, 12, 5225 – 5230
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
5229

D. V. Konarev, G. Saito et al.
molecules are disordered between two orientations and have 0.39:0.28
and 0.17:0.16 occupancies, respectively.
[8] M. Rossi, J. P. Glusker, L. Randaccio, M. F. Summers, P. J. Toscano,
L. G. Marzilli, J. Am. Chem. Soc. 1985, 107, 1729–1738.
[9] S. Stevenson, G. Rice, T. Glass, K. Harich, F. Cromer, M. R. Jordan,
J. Craft, E. Hadju, R. Bible, M. M. Olmstead, K. Maitra, A. J.
Fisher, A. L. Balch, H. C. Dorn, Nature 1999, 401, 55–57.
[10] M. M. Olmstead, A. Bettencourt-Dias, J. C. Duchamp, S. Stevenson,
D. Marciu, H. C. Dorn, A. L. Balch, Angew. Chem. 2001, 113, 1263–
1265; Angew. Chem. Int. Ed. 2001, 40, 1223–1225.
CCDC-291006 and 291007contain the supplementary crystallographic
data for compounds 2 and 1, respectively. These data can be obtained
free of charge from The Cambridge Crystallographic Data Center via
www.ccdc.cam.uk.data_request/cif.
[11] D. V. Konarev, S. S. Khasanov, A. Otsuka, Y. Yoshida, R. N. Lyubov-
skaya, G. Saito, Chem. Eur. J. 2003, 9, 3837–3848.
Acknowledgements
[12] D. V. Konarev, I. S. Neretin, G. Saito, Yu. L. Slovokhotov, A.
Otsuka, R. N. Lyubovskaya, Dalton Trans. 2003, 3886–3891.
[13] R. Subramanian, P. Boulas, M. N. Vijayashree, F. DꢁSouza, M. T.
Jones, K. M. Kadish, J. Chem. Soc. Chem. Commun. 1994, 1847–
1848.
This work was partly supported by the Grant-in-Aid Scientific Research
from the Ministry of Education, Culture, Sports, Science and Technology,
Japan (152005019 and COEPROGRAMS), the RFBR (grant N 06-03-
32824a), the Russian Science Support Foundation, and INTAS YSF (05-
109-4653).
[14] E. Allard, L. Riviꢂre, J. Delaunay, D. Dubois, J. Cousseau, Tetrahe-
dron Lett. 1999, 40, 7223–7226.
[15] C. A. Reed, R. D. Bolskar, Chem. Rev. 2000, 100, 1075–1120.
[16] D. V. Konarev, S. S. Khasanov, G. Saito, A. Otsuka, Y. Yoshida,
R. N. Lyubovskaya, J. Am. Chem. Soc. 2003, 125, 10074–10083.
[17] A. Ozarowski, H. M. Lee, A. L. Balch, J. Am. Chem. Soc. 2003, 125,
12606–12614.
[1] D. M. Guldi, Chem. Soc. Rev. 2002, 31, 22–36.
[2] D. Gust, T. A. Moore, A. L. Moore, Acc. Chem. Res. 2001, 34, 40–
48.
[18] T. Picher, R. Winkler, H. Kuzmany, Phys. Rev. B 1994, 49, 1587 9–
15889.
[19] D. V. Konarev, S. S. Khasanov, A. Otsuka, Y. Yoshida, G. Saito, J.
Am. Chem. Soc. 2002, 124, 7648–7649.
[20] P.-M. Allemand, K. C. Khemani, A. Koch, F. Wudl, K. Holczer, S.
Donovan, G. Grꢃner, J. D. Thompson, Science 1991, 253, 301–303.
[21] T. Kitagawa, Y. Lee, K. Takeuchi, Chem. Commun. 1999, 1529–
1530.
[3] M. M. Olmstead, D. A. Costa, K. Maitra, B. C. Noll, S. L. Phillips,
P. M. Van Calcar, A. L. Balch, J. Am. Chem. Soc. 1999, 121, 7090–
7097.
[4] D. R. Evans, N. L. P. Fackler, Z. Xie, C. E. F. Rickard, P. D. W. Boyd,
C. A. Reed, J. Am. Chem. Soc. 1999, 121, 8466–8474.
[5] D. V. Konarev, I. S. Neretin, Yu. L. Slovokhotov, E. I. Yudanova,
N. V. Drichko, Yu. M. Shulꢁga, B. P. Tarasov, L. L. Gumanov, A. S.
Batsanov, J. A. K. Howard, R. N. Lyubovskaya, Chem. Eur. J. 2001,
7, 2605–2616.
[22] Bruker Analytical X-ray Systems, Madison, Wisconsin (USA), 1999.
[6] D. V. Konarev, A. Yu. Kovalevsky, X. Li, I. S. Neretin, A. L. Litvi-
nov, N. V. Drichko, Yu. L. Slovokhotov, P. Coppens, R. N. Lyubov-
skaya, Inorg. Chem. 2002, 41, 3638–3646.
Received: January 30, 2006
[7] P. D. W. Boyd, C. A. Reed, Acc. Chem. Res. 2005, 38, 235–242.
Published online: May 2, 2006
5230
www.chemeurj.org
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2006, 12, 5225 – 5230