Synthesis, crystal structures, magnetic properties and photoconductivity of C60 and C70 complexes with metal dialkyldithiocarbamates M(R2dtc)x, where M = CuII, CuI, AgI, ZnII, CdII, HgII, Mn II, NiII, and PtII; R = Me, Et, and nPr

Article abstract of DOI:10.1002/ejic.200501110

New complexes of fullerenes C₆₀ and C₇₀ with metal dialkyldithiocarbamates, [M(R₂dtc)_x]·[C ₆₀(₇₀)]·[Solvent], R = Et [M = Cu^II (C₆₀, 1; C₇₀, 2), Cu^I (C₆₀, 3; C₇₀, 4), Ag^I (C₆₀, 5), Zn^II (C ₆₀, 6), Cd^II (C₆₀, 7; C₇₀, 8), Hg^II (C₆₀, 9), Mn^II (C₇₀, 10)], R = Et and Me [M = Cu^II (C₆₀, 11), and Zn^II (C ₆₀, 12)], and R = nPr [M = Cu^II (C₆₀, 13), Ni^II (C₆₀, 14), and Pt^II (C₆₀, 15)] were obtained. M(R₂dtc)_x efficiently cocrystallized with fullerene molecules as tetrahedral monomers (6, 12), dimers (1, 7, 11), and tetramers (3, 4). Fullerene molecules form closely packed hexagonal and square layers in 1, 7, and 11, hexagonal and tetragonal 3D structures in 6 and 12, and island motifs in 3 and 4. Complexes 1-15 have a neutral ground state. However, the formation of the complexes with fullerenes changes the environment of paramagnetic Cu^II and Mn^II. The EPR spectra of 1, 2, 11, and 13 are essentially modified relative to those of pristine Cu(R ₂dtc)₂ because of a weak coordination of Cu^II to fullerene and a flattening of the central (NCS₂)₂Cu fragments. Complex 10 shows a spectrum exhibiting features from 50 to 600 mT and manifests strong antiferromagnetic coupling of spins with a Weiss temperature of -96 K and the maximum of magnetic susceptibility at 46 K. Such magnetic behavior can be explained by the formation of [Mn(Et₂dtc) ₂]₂ dimers in 10. The illumination of the crystals of 1, 2, and 7 by white light results in up to a 10³ increase in photocurrent. The photoconductivity spectra have maxima at 470, 450-650, and 660 nm for 1, 2, and 7, respectively. Photogeneration of free charge carriers is realized by photoexcitation of Cu(Et₂dtc)₂ in 1 and 2, and by charge transfer from Cd(Et₂dtc)₂ to C₆₀ molecules in 7. The decrease of photocurrent in 1 and 7 in a weak magnetic field with B₀ < 0.5 T was found. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.

Full text of DOI:10.1002/ejic.200501110

FULL PAPER
DOI: 10.1002/ejic.200501110
Synthesis, Crystal Structures, Magnetic Properties and Photoconductivity of
C60 and C70 Complexes with Metal Dialkyldithiocarbamates M(R2dtc)x, where
M = CuII, CuI, AgI, ZnII, CdII, HgII, MnII, NiII, and PtII; R = Me, Et, and nPr
Dmitri V. Konarev,*[a] Andrey Y. Kovalevsky,[b] Salavat S. Khasanov,[c] Gunzi Saito,[d]
Dmitri V. Lopatin,[e] Alexey V. Umrikhin,[e] Akihiro Otsuka,[f] and Rimma N. Lyubovskaya[a]
Keywords: Crystal engineering / Fullerenes / Metal dialkyldithiocarbamates / Magnetic properties / Photoconductivity
New complexes of fullerenes C60 and C70 with metal dialkyl-
dithiocarbamates, [M(R2dtc)x]·[C60 70)]·[Solvent], R = Et [M =
CuII (C60, 1; C70, 2), CuI (C60, 3; C70, 4), AgI (C60, 5), ZnII (C60
and a flattening of the central (NCS2)2Cu fragments. Complex
10 shows a spectrum exhibiting features from 50 to 600 mT
and manifests strong antiferromagnetic coupling of spins with
(
,
6), CdII (C60, 7; C70, 8), HgII (C60, 9), MnII (C70, 10)], R = Et and a Weiss temperature of –96 K and the maximum of magnetic
Me [M = CuII (C60, 11), and ZnII (C60, 12)], and R = nPr [M =
CuII (C60, 13), NiII (C60, 14), and PtII (C60, 15)] were obtained.
M(R2dtc)x efficiently cocrystallized with fullerene molecules as
tetrahedral monomers (6, 12), dimers (1, 7, 11), and tetramers
(3, 4). Fullerene molecules form closely packed hexagonal and
square layers in 1, 7, and 11, hexagonal and tetragonal 3D
structures in 6 and 12, and island motifs in 3 and 4. Complexes
1–15 have a neutral ground state. However, the formation of
the complexes with fullerenes changes the environment of
paramagnetic CuII and MnII. The EPR spectra of 1, 2, 11, and
13 are essentially modified relative to those of pristine
Cu(R2dtc)2 because of a weak coordination of CuII to fullerene
susceptibility at 46 K. Such magnetic behavior can be ex-
plained by the formation of [Mn(Et2dtc)2]2 dimers in 10. The
illumination of the crystals of 1, 2, and 7 by white light results
in up to a 103 increase in photocurrent. The photoconductivity
spectra have maxima at 470, 450–650, and 660 nm for 1, 2,
and 7, respectively. Photogeneration of free charge carriers is
realized by photoexcitation of Cu(Et2dtc)2 in 1 and 2, and by
charge transfer from Cd(Et2dtc)2 to C60 molecules in 7. The
decrease of photocurrent in 1 and 7 in a weak magnetic field
with B0 Ͻ 0.5 T was found.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2006)
porphyrins and metalloporphyrins,[9–11] porphyrazines,[12]
metallocenes,[13–17] and others.[6] Great interest in fullerene
complexes was evoked by their intriguing properties. Ionic
compounds show ferromagnetism[5] and reversibly form σ-
bonded structures.[15–17] Neutral complexes were also used
as templates for the preparation of fullerene polymers.[18]
They can manifest photoconductivity[19] and excited ionic
states upon photoexcitation by white light.[20] The variation
of a donor component allows one to affect the packing of
fullerene molecules in a crystal, the charged state of fuller-
enes and, consequently, the properties of the resulting com-
plexes. The search for new classes of donor molecules for
the preparation of fullerene complexes can result in the de-
sign of new promising compounds. Recently, we have found
that dimeric copper() diethyldithiocarbamate, Cu(Et2dtc)2,
co-crystallizes with fullerenes to form a molecular complex,
[Cu(Et2dtc)2]2·C60, with a layered structure.[21] This work
was extended to metal() dithiocarbamates with bulkier
Introduction
Fullerenes form a wide variety of donor-acceptor com-
plexes ranging from molecular to ionic ones[1–3] with dif-
ferent classes of organic and organometallic donors: aro-
matic hydrocarbons,[4] amines,[5–7] tetrathiafulvalenes,[6,8]
[a] Institute of Problems of Chemical Physics RAS,
Chernogolovka, Moscow region 142432, Russia
Fax: +7-96-515-5420
E-mail: konarev@icp.ac.ru
[b] State University of New York at Buffalo,
Buffalo, New York, 14260 USA
E-mail: bioayk@langate.gsu.edu
[c] Institute of Solid State Physics RAS,
Chernogolovka, Moscow region, 142432, Russia
E-mail: khasanov@issp.ac.ru
[d] Division of Chemistry, Graduate School of Science, Kyoto Uni-
versity,
Sakyo-ku, Kyoto 606-8502, Japan
Fax: +81-75-753-4035
E-mail: saito@kuchem.kyoto-u.ac.jp
[e] Department of Physics, Tambov State University,
Tambov, 392622 Russia
benzyl
substituents
(abbreviation:
Bnz),
namely,
E-mail: lopatin@tsu.tmb.ru
Cu(Bnz2dtc)2, Ni(Bnz2dtc)2, Pd(Bnz2dtc)2, and Pt(Bnz2dtc)2.
They co-crystallize with C60 to form M(Bnz2dtc)2·
C60·(C6H5Cl)0.5 complexes.[22] In contrast to dimeric
Cu(dedtc)2, M(Bnz2dtc)2 are monomers with planar confor-
mation of the central (NCS2)2M fragment, which is charac-
[f] Research Center for Low Temperature and Materials Sciences,
Kyoto University,
Sakyo-ku, Kyoto, 606-8502, Japan
E-mail: otsuka@kuchem.kyoto-u.ac.jp
Supporting information for this article is available on the
WWW under http://www.eurjic.org or from the author.
Eur. J. Inorg. Chem. 2006, 1881–1895
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1881

D. V. Konarev et al.
FULL PAPER
teristic of NiII, PdII, and PtII dithiocarbamates.[23–27] More- C60 and a fivefold molar excess of the corresponding
over, Pd(Bnz2dtc)2 forms a multi-component ionic complex M(Et2dtc)x were dissolved in benzonitrile at 60 °C over 2 h,
containing C60 and bis(benzene)chromium ion-radicals: the solutions were cooled down, filtered off, and the spectra
[CrI(C6H6)2·+]·(C60·–)·[Pd(Bnz2dtc)2]0.5. The complex dem- of the resulting solutions were measured in anaerobic con-
·–
onstrates unusual low-temperature dimerization of C60
ditions in the 600–1600 nm range. CuI, CoII, and VII di-
with a relatively large hysteresis and the decrease of the di- ethyldithiocarbamates reduce C60 to a radical anion, and
–
merization temperature at a fast cooling rate.[22] Thus, metal an absorption band characteristic of C60 is manifested at
dialkyldithiocarbamates, M(R2dtc)x, can successfully be 1070 nm. On the contrary, Mn(Et2dtc)2 cannot reduce C60.
used in the design of molecular and ionic complexes with These observations are in agreement with redox potentials
fullerenes. It should be noted that although we have known of metal() dithiocarbamates. Related octahedral MIII
-
1–/0
about M(R2dtc)x for a long time, their donor-acceptor com- (dtc)3
(M3+/M2+ transition) are reduced at –0.77 V for
plexes with π-acceptors are rare. To our knowledge, only V3+/2+, and –0.92 V for Co3+/2+, whereas the reduction po-
some complexes of molybdenum and tungsten dialkyldithio- tential for Mn3+/2+ (–0.08 V) is shifted to positive values (all
carbamates with tetracyanoquinodimethane were de- vs. Ag/AgCl).[30] C60 has the first E0/– potential at
scribed.[28,29]
–0.485 V(vs. Ag/AgCl).[32]
M(R2dtc)x can easily be modified. It is possible to vary
molecular structures of M(R2dtc)x by changing “M” or the
length of alkyl substituents (R). Donor properties of
M(R2dtc)x can also be varied from weak donors to strong
ones[30] potentially able to ionize fullerenes. Some of
2. Synthesis of Solid Complexes
The complexes obtained and the data from the elemental
M(R2dtc)x have broad absorption in the visible range or analysis are listed in Table 1. The ability of M(R2dtc)x to
outstanding magnetic properties [for example, FeIII
-
co-crystallize with C60 and C70 as well as the composition
(Et2dtc)2Cl is the first single-component ferromagnet with of the complexes depend on the metal (M) and the length
Tc = 2.46 K][31] and, therefore, they can be used as light of the alkyl substituents (R). Pristine M(R2dtc)2 (R = Et,
harvesting or magnetic components for the complexes.
nPr) have different conformations of the central (NCS2)2M
In the present work we studied the effect of M(R2dtc)x fragment. Ni(R2dtc)2 and Pt(R2dtc)2 have square planar
(depending on M and R) on composition, structure, elec- conformation.[23–27] Zn(R2dtc)2,[33–35] Cd(R2dtc)2,[36,37] and
tronic, and physical properties of their complexes with Fe(Et2dtc)2[38] are dimers with a tetrahedral environment of
fullerenes. We used monomeric, dimeric, and tetrameric MII. Mn(Et2dtc)2 is a polymer with an octahedral environ-
[40–42]
[43]
M(R2dtc)x and varied the length of alkyl (R) substituents ment of MnII.[39] Hg(R2dtc)2
and Cu(R2dtc)2
have
(Me, Et, and nPr). M(R2dtc)x were both weak and strong both square planar or square pyramidal dimeric conforma-
donors. The interaction of C60 with the strongest donors tions.
(CuI, MnII, CoII, and VII diethyldithiocarbamates) was
M(Et2dtc)2 (M = CdII, HgII, and MnII) co-crystallize
studied in benzonitrile solution. Fifteen complexes of C60 with fullerenes in dimeric conformation to form 1:2 [C60/
and C70 with CuII, CuI, AgI, ZnII, CdII, HgII, MnII, NiII, M(R2dtc)2] complexes. As this takes place, Cd(Et2dtc)2, and
and PtII dialkyldithiocarbamates were obtained and charac- Mn(Et2dtc)2 precipitate C60 and C70 complexes from C6H6,
terized in the solid state. The composition of the complexes C6H5Cl, and C6H4Cl2 solutions in nearly a quantitative
was determined from elemental analysis and X-ray diffrac- yield [a similar ability was found for Fe(Et2dtc)2]. On the
tion on single crystals. Crystal structures of seven com- contrary, square planar Ni(Et2dtc)2, and Pt(Et2dtc)2 or Co-
plexes were solved. FTIR- and UV/Visible-NIR spectra of (Et2dtc)2 and V(Et2dtc)2, which reduce C60 in solution, do
the complexes were studied. Magnetic properties of the not form crystals of the complexes with fullerenes.
complexes with M(R2dtc)x (M = CuI, CuII, and MnII) were
Elongation of alkyl substituents in M(nPr2dtc)2 drasti-
investigated by SQUID and EPR techniques. Photoconduc- cally changes their complex formation with fullerenes.
tivity of single crystals of four C60 and C70 complexes with Ni(nPr2dtc)2 and Pt(nPr2dtc)2 with square planar confor-
Cu(Et2dtc)2 and Cd(Et2dtc)2 was studied upon illumination mation form 2:1 [C60/M(nPr2dtc)2] complexes with C60.
with white light. The comparison of the photoconductivity Similarly, among different metal() dibenzyldithiocarba-
and the absorption spectra allows one to suggest the mecha- mates only Ni(Bnz2dtc)2, Pd(Bnz2dtc)2, and Pt(Bnz2dtc)2
nisms of free charge carrier generation. The effect of mag- with the same conformation co-crystallize with C60.[22] It is
netic field with B0 Ͻ 0.5 T on photoconductivity was deter- interesting to note that Cu(R2dtc)2 form 1:2, 2:1, and 1:1
mined.
[C60:Cu(R2dtc)2] complexes independently of the R (MeEt,
Et, nPr, and Bnz) length. It seems possible that Cu-
(R2dtc)2 in the complexes with fullerenes can adopt both
square planar[43,44] and square pyramidal dimeric confor-
mations.[43]
Results and Discussion
1. Interaction of Fullerenes with Metal(II
Diethyldithiocarbamates in Solution
)
The crystals of the complexes were obtained by the evap-
oration of solutions containing fullerenes and correspond-
The interaction of the strongest M(Et2dtc)2 donors (M = ing donors. We used the diffusion method to prepare the
CuI, MnII, CoII, and VII) with C60 was studied in solution. complexes with air-sensitive M(R2dtc)x and Cd(Et2dtc)2.
1882
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Eur. J. Inorg. Chem. 2006, 1881–1895

Properties and Photoconductivity of C60 and C70 Complexes
FULL PAPER
Table 1. Data of elemental analysis for 1–15.
Elemental analysis found/calcd.
Color and shape
C [%]
H [%]
N [%]
Cl [%]
S [%]
M [%]
[a] [21]
[Cu(Et2dtc)2]2·C60
1
2
3
4
5
66.46
66.70
83.54
83.51
51.71
50.75
53.68
53.26
82.14
80.85
3.08
2.77
2.24
1.42
3.11
3.19
2.97
3.03
1.48
1.52
4.10
3.88
1.75
1.77
3.75
4.14
3.50
3.93
1.33
1.32
0
0
black hexagonal
plates
black prisms
17.77
8.12
8.88
[Cu(Et2dtc)2]·(C70)2·(C6H5Cl)0.5
{[CuI(Et2dtc)]4}5·(C60)3·(C6H4Cl2)4
{[CuI(Et2dtc)]4}5·(C70)3·(C6H4Cl2)4
AgI(Et2dtc)·C60·C6H6
0.91
1.12
5.58
4.21
4.64
3.93
–
4.06
[a]
[a]
black prisms
black prisms
black prisms
18.93
17.97
6.07
18.78
17.83
10.24
–
[a]
Zn(Et2dtc)2·C60·(C6H5Cl)0.5·(C6H6)0.5
6
7
According to X-ray diffraction data
brown prisms
red-brown rhombus
[a]
{Cd(Et2dtc)2}2·C60
61.02
61.50
64.41
65.20
56.00
55.02
68.88[b]
3.04
2.67
3.32
2.41
2.35
2.39
2.59
3.79
3.73
3.38
3.33
3.37
3.34
3.69
–
–
17.09
15.45
15.29
15.01
13.57
23.96
{Cd(Et2dtc)2}2·C70
{Hg(Et2dtc)2}2·C60
{Mn(Et2dtc)2}2·C70
8
9
Ͻ0.7
red-brown rhombus
0
–
–
0
black hexagonal
plates
black elongated
parallelepipeds
10
70.05
66.13
65.92
2.98
2.21
2.31
3.63
4.01
4.04
0
–
–
16.60
18.49
7.13
9.24
[a]
[Cu(EtMedtc)2]2·C60
11
black rhombus
[a]
[Zn(EtMedtc)2]3·(C60 2
)
12
13
According to X-ray diffraction data
black rhombus
thin needles
[Cu(nPr2dtc)2]·(C60 2
)
86.74
86.67
87.01
86.91
80.81
80.93
1.48
1.51
1.50
1.50
2.30
1.41
1.44
1.51
1.47
1.50
1.70
1.41
0
0
0
0
0
0
6.89
6.88
6.44
3.42
3.21
9.81
[Ni(nPr2dtc)2]·(C60 2
)
14
15
thin needles
thin needles
[Pt(nPr2dtc)2]·(C60 2
)
[a] The composition of the complex was proved by X-ray diffraction on single crystals. [b] A smaller content of carbon relative to the
calculated values may have been caused by the addition of oxygen during elemental analysis because of the high air-sensitivity of
Mn(Et2dtc)2.
3. Crystal Structures
are arranged strictly above the C60 spheres, whereas flexible
ethyl substituents occupy available cavities in the C60 layers.
The effective packing of Cd(Et2dtc)2 and C60 molecules in a
crystal is attained due to a butterfly shape of Cd(Et2dtc)2
dimers (Figure 1), which allows them to encapsulate C60
molecules (Figure 2, c).
Main geometric parameters of M(R2dtc)x and van der
Waals (vdW) contacts in the complexes with fullerenes are
listed in Table 2. Molecular structures of M(R2dtc)x are
shown in Figure 1.
The crystal structure of [Cu(Et2dtc)2]2·C60 (1) has been
The packing of Cd(Et2dtc)2 dimers in the layer has a par-
quet-like motif (Figure 2, b). The shortest Cd···C(C60) con-
described previously.[21]
[Cd(Et2dtc)2]2·C60 (7) has a crystal structure similar to tacts of 3.587 and 3.592 Å are formed with two carbon
that of 1. Cd(Et2dtc)2 and C60 molecules are ordered at atoms of the 6–6 bond of C60. These contacts are noticeably
120 K. Complex 7 has a layered structure (Figure 2, parts longer than the Cu···C(C60) contacts in 1 (3.334 and
a and b), in which layers of closely packed C60 molecules 3.379 Å).[21] Co-crystallization of Cd(Et2dtc)2 with C60 does
alternate with those composed of Cd(Et2dtc)2 dimers. Each not affect its geometry. The pristine donor has a dimeric
C
60 molecule has four neighbors in the layer with the short- structure with a nearly tetrahedral environment of CdII with
est interfullerene center-to-center distance of 9.99 Å along three short equatorial bonds and one short axial bond (an
the diagonal to the bc-plane (Figure 2, b). This distance is average length is 2.575 Å). One equatorial bond is notice-
close to that in pure C60 crystals at 153 K (9.94 Å).[45] The ably longer than the other ones (2.812 Å).[36] The dimeric
vdW C···C contacts are 3.33–3.77 Å. Two other neighbor- structure of Cd(Et2dtc)2 is retained in 7. Averaged lengths
ing fullerenes are arranged in the c-direction with a center- of three short equatorial bonds and one short axial bond
to-center distance of 10.54 Å (longer than the vdW dia- are nearly the same (2.577 Å), but the long equatorial bond
meter of C60 molecules of 10.18 Å). Therefore, C60 mole- is elongated to 2.877 Å. Two of four ethyl groups of
cules have a square arrangement in the layers.
Cd(Et2dtc)2 are directed towards the fullerene layer in 7
The projection of the Cd(Et2dtc)2 layer on the C60 one is (Figure 2, c), whereas in 1 three of four ethyl groups of
shown in part b of Figure 2. The central CdS4 fragments Cu(Et2dtc)2 are directed towards the fullerene layer.[21]
Eur. J. Inorg. Chem. 2006, 1881–1895
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1883

D. V. Konarev et al.
FULL PAPER
Table 2. Geometric parameters for metal dialkyldithiocarbamates in the complexes with fullerenes.
Complex
Geometry
1
11
Dimer
7
3
4
6
12
Dimer
Dimer
Tetramer[a]
Tetramer[a]
Tetrahedral
monomer
Tetrahedral
monomer[b]
Bond lengths [Å]
1
2
3
4
5
6
7
8
2.3354(8)
2.2978(8)
2.2994(9)
2.3218(8)
3.030(1)
1.725 (3)
1.722(3)
1.720(3)
1.724(3)
1.321(4)
1.320(4)
2.3135
2.3057(15)
2.3361(12)
2.3389(12)
2.3177(14)
2.7869(12)
1.718(5)
1.707(5)
1.717(6)
1.724(5)
1.328(7)
2.8771(10)
2.544(9)
2.5333(10)
2.6330(10)
2.5988(12)
1.758(4)
1.714(3)
1.737(3)
1.717(4)
1.337(4)
1.331(5)
2.6468
2.245(3)–
2.281(3)
2.247(3)–
2.278(3)
2.3449(9)
2.3390(9)
2.3425(10)
2.3350(9)
–
1.705(4)
1.735(3)
1.733(3)
1.733(6)
1.340(5)
1.326(4)
2.3403
2.340(3)
2.343(3)
2.394(3)
2.357(3)
–
1.695(13)
1.712(14)
1.743(12)
1.1.754(11)
1.281(14)
1.355(16)
2.358
1.700(10)–
1.764(10)
1.698(11)–
1.777(10)
9
10
11
1.324(4)–
1.335(4)
2.2567
1.317(14)–
1.342(15)
2.2618
1.335(7)
2.3246
M···S (1–4) aver.
Bond angles [°]
1
2
3
4
76.90(3)
77.06(3)
164.84(3)
173.00(3)
76.73(5)
76.44(5)
162.67(6)
169.49(5)
66.67(3)
70.29(3)
143.80(3)
157.64(4)
122.6(1)–
123.18(11)
121.83(11)–
123.65(10)
77.89(3)
78.29(3)
127.18(4)
128.19(4)
78.17(12)
78.15(13)
129.21(13)
130.28(12)
M···M distances [Å]
3.529(1)
3.561(2)
3.802(2)
tetrahedron
2.5855(17)–
2.6239(17)
tetrahedron
2.5698(18)–
2.6306(18)
–
–
Donor–Fullerene interactions, shortest vdW contacts
M···C(Ful.) [Å]
S···C(Ful.) [Å]
N···C(Ful.) [Å]
H···C(Ful.) [Å]
3.269, 3.307
3.52–3.89
3.68–3.81
2.84–2.94
3.334, 3.379
3.52–3.95
3.72–3.77
2.97–3.00
3.587, 3.592
3.51–3.80
3.52–3.77
2.86–3.13
4.800, 4.838
3.59–3.99
3.89–3.95
2.92–3.26
4.437,4.476
3.66–3.84
3.66–3.95
2.78–3.08
3.659, 3.822
3.35–3.76
3.37–3.52
2.95–3.13
3.66–3.94
3.43–3.63
3.65–3.75
3.06–3.28
Fullerene–Fullerene interaction
Packing of
fullerenes
hexagonal
layers,
hexagonal
layers,
square layers,
4 neighbors
isolated
isolated
hexagonal, 3D, tetragonal, 3D,
6 neighbors
4 neighbors
6 neighbors
6 neighbors
Interfullerene
center-to-center
distances [Å]
10.02 (×4),
10.25 (×2)
9.89 (×4),
10.02 (×2)
9.99 (×4)
shortest 13.5
shortest 13.5
10.38 (×2),
10.13, 9.93,
9.81, 9.74
9.83, 9.86,
9.88, 10.09
Interfullerene C···C
contacts [Å]
3.329–3.466,
–
3.276–3.410,
3.392–3.470
3.328–3.770,
–
–
–
3.250–3.360
3.269–3.410
[a] The ranges for the bond lengths and angles are given for 3 and 4. [b] The bond lengths and angles for Zn(EtMedtc)2 are given for
one of three crystallographically independent molecules.
[45]
[Cu(EtMedtc)2]2·C60 (11) is isostructural to 1. The substi- tance in pure C60
justifying the formation of closely
tution of two of four ethyl groups by methyl ones results in packed hexagonal layers.
the decrease of the unit cell parameters of 11 relative to
The projection of the Cu(EtMedtc)2 layer on the C60
those of 1 (see Table 4). C60 and Cu(EtMedtc)2 molecules layer is shown in Figure 3, b. The central CuS4 fragments
are ordered. Complex 11 also has a layered structure (Fig- arranged above C60 spheres allow two flexible ethyl groups
ure 3, a and b) with six neighbors to each C60 molecule. to occupy cavities in the C60 layers. C60 forms shortened
The shortest interfullerene center-to-center distances are Cu···C(C60) contacts of 3.334 and 3.379 Å by two carbon
9.89 (four neighbors along the diagonal to the bc-plane) atoms of one 6–6 bond (Figure 3, b). VdW S, N and
and 10.02 Å (two neighbors in the c-direction; Figure 3, b). H···C(C60) contacts are close to those in 1 and 7
For both cases the vdW C···C contacts between adjacent (Table 2).
fullerenes of 3.28–3.41 and 3.39–3.47 Å are shorter than
Cu(EtMedtc)2 has a dimeric structure in 11 with a square
3.42 Å and center-to-center distances are close to the dis- pyramidal environment of CuII atoms (Figure 1) with four
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Properties and Photoconductivity of C60 and C70 Complexes
FULL PAPER
Figure 1. Molecular structures of M(R2dtc)x in the complexes with
fullerenes: {Cd(Et2dtc)2}2, {Cu(Et2dtc)2}2 and {Cu(EtMedtc)2}2
dimers; tetrahedral Zn(Et2dtc)2 and Zn(EtMedtc)2 monomers and
[CuI(Et2dtc)]4 tetramers.
short equatorial bonds (the average length is 2.325 Å) and
one relatively long axial bond (2.787 Å). Both ethyl groups
of Cu(EtMedtc)2 are directed towards the fullerene layer.
Thus, 1, 7, and 11 have similar crystal structures.
However, the differences in the molecular structures of
M(R2dtc)2 and the length of the alkyl substituents provide
their noticeable modifications. The packing motif of the ful-
lerene layer changes from closely packed hexagonal layers
in 11, to intermediate layers in 1 (four and two neighbors
with 10.02 and 10.25 Å center-to-center interfullerene dis-
tances)[21] and finally to square layers in 7. The character
of M(R2dtc)2-fullerene interactions also changes. Weakly
Figure 2. Crystal structure of 7: the view of the unit cell on the ab-
(a) and bc-planes (b); a mutual arrangement of concave Cd-
(Et2dtc)2 fragments and a spherical C60 molecule (c).
bound Cu(R2dtc)2 dimers with relatively long axial bonds tions in 1 and 11 with corresponding dihedral angles of 9.8,
have a more planar shape of the (NCS2)2M fragments than 13.6° and 9.5, 12.6°, respectively.
those in strongly bound Cd(Et2dtc)2 dimers with a short
Zn(Et2dtc)2·C60·(C6H5Cl)0.5·(C6H6)0.5 (6) crystallizes in a
axial bond. The dihedral angles between the NCS2M planes triclinic lattice. C60 and Zn(Et2dtc)2 molecules are ordered,
are 160.9 and 158.6° in 1 and 11, and only 143.8° in 7 pro- whereas C6H5Cl and C6H6 molecules share one position
viding shorter Cu···C(C60) distances (by about 0.3 Å) in 11 with equal occupancies and are disordered. Complex 6 has
and 1 than the Cd···C(C60) distances in 7. However, the a unique cage structure with large channels along the a-axis
more concave surface of the Cd(Et2dtc)2 fragments results accommodating Zn(Et2dtc)2 and solvent molecules. The
in better conditions for the π-π interaction between the channels are completely surrounded by the fullerene mole-
NCS2Cd planes and two adjacent C60 hexagons (Figure 2, cules, which form a hexagonal 3D framework (Figure 4).
c) since the dihedral angle of 143.8° is close to that between Each C60 molecule has six neighbors. The center-to-center
adjacent C60 hexagons (138.5°). As a result, the NCS2Cd distances for three of them (9.74, 9.81, and 9.93 Å) are close
planes and the C60 hexagons arrange parallel to each other to that distance in pure C60,[45] whereas the other ones are
with the dihedral angles between them equal only to 0.8 larger (10.38 Å ×2 and 10.13 Å). Shortened vdW C···C con-
and 8.2°. High steric complementarity is probably a reason tacts between the closest fullerenes are 3.250–3.360 Å.
for the ability of Cd(Et2dtc)2 to quantitatively precipitate
Zn(Et2dtc)2 forms a complex with C60 in a monomeric
C60 and C70 complexes from solutions. More planar state with nonplanar pseudo-tetrahedral configuration of
Cu(R2dtc)2 provides worse conditions for the π-π interac- ZnII (the dihedral angle between two NCS2Zn planes being
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D. V. Konarev et al.
FULL PAPER
91.5°) (Figure 1). This conformation is for the first time ob-
served for Zn(Et2dtc)2. Similar geometry of the (NCS2)2Zn
fragment was reported for Zn(Bnz2dtc)2 with bulky benzyl
substituents,[46] whereas pristine Zn(R2dtc)2 with R = Et,
nPr, iPr substituents have dimeric structures.[33–35]
Because of the tetrahedral geometry, only half of each
Zn(Et2dtc)2 molecule forms vdW contacts with C60
(Table 2). The closest Zn···C(C60) distances are 3.659 and
3.822 Å. The other half of the Zn(Et2dtc)2 molecule locates
above the adjacent Zn(Et2dtc)2.
The substitution of two ethyl groups by methyl ones
changes the packing motif in [Zn(EtMedtc)2]3·(C60)2 (12).
In contrast to previously described complexes, both C60
molecules are disordered at 90 K between two orientations
with 66/34 and 58/42% occupancies. These orientations are
linked by the rotation of the C60 molecule by 180° about
the axis passing through the centers of two oppositely lo-
cated 5–6 bonds. There is also certain disorder in the posi-
tions of ethyl and methyl groups in Zn(EtMedtc)2. The
complex has 3D packing of fullerenes, in which each C60
molecule has four neighbors and is located in the center of
a distorted tetrahedron. This 3D packing can be split in
strongly puckered C60 layers parallel to the ac-plane (Fig-
ure 5). Three neighbors are seen in this plane, whereas the
fourth neighbor is located in the adjacent layers. The center-
to-center distances are in the 9.83–10.09 Å range (the vdW
radius of C60 is 10.18 Å) and the shortest C···C contacts lie
in the 3.27–3.41 Å range. The cavities in the 3D framework
are occupied by Zn(EtMedtc)2 molecules. One Zn-
(EtMedtc)2 molecule arranges parallel to the ac-plane and
two other ones are perpendicular to this plane (Figure 5).
Because of the strong puckering of fullerene layers, each
Zn(EtMedtc)2 molecule forms vdW contacts with four ful-
lerene ones. The Zn···C(C60) distances of 3.66–3.94 Å are
similar to those in 6.
Figure 3. Crystal structure of 11: the view of the unit cell of 11 on
the ac- (a) and bc-planes (b).
Figure 5. The view of the crystal structure of 12 on the ac-plane.
C60 molecules occupy two levels. Molecules belonging to one level
are connected by thin lines.
{[CuI(Et2dtc)]4}5·(C60)3·(C6H4Cl2)4 (3) and {[CuI-
(Et2dtc)]4}5·(C70)3·(C6H4Cl2)4 (4) are isostructural and have
high-symmetry cubic unit cells with parameters of
Figure 4. The view of the unit cell of 6 along the a-axis.
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Properties and Photoconductivity of C60 and C70 Complexes
FULL PAPER
43.7822(4) (3) and 44.2911(3) (4) Å and unusually great vol- 4. Magnetic Properties of the Complexes
umes of 83925.3(13) (3) and 86885.9(10) Å (4). Two sym-
EPR spectroscopy is a sensitive tool used to study
metrically independent C60 molecules are disordered. One
of them is located on a twofold axis and the other molecule
is on a fourfold axis. Because of the disorder, C60 molecules
have two and four orientations, respectively. [CuI(Et2dtc)]4
and solvent C6H4Cl2 molecules are located in general posi-
tions and are ordered.
The complexes have an island motif of fullerene packing
with the shortest interfullerene center-to-center distances of
13.5 Å. Loose layers can be outlined in the bc-plane. The
main structural motif of these layers is shown in Figure 6.
There are large (right in Figure 6) and small (left in Fig-
ure 6) squares consisting of five and four fullerene mole-
cules. Each small square is surrounded by four large squares
and vice versa. As this takes place, both squares have one
common C60 molecule. Small squares accommodate five
[CuI(Et2dtc)]4 molecules, whereas large squares accommo-
date eight [CuI(Et2dtc)]4 and eight C6H4Cl2 molecules. It is
interesting that all eight C6H4Cl2 molecules surround one
changes in a local environment of CuII atoms at the forma-
tion of fullerene complexes with Cu(R2dtc)2. Pristine
Cu(R2dtc)2 with R = Et, nPr possess dimeric structures
with square pyramidal geometry of CuII (the coordination
number is 5).[43] Such geometry is characterized by the EPR
spectrum shown in part a of Figure 7. Cu(EtMedtc)2 has
an asymmetric structure and as a result shows a more asym-
metric EPR signal (Supporting Information).
C
60 molecule (Figure 6). The adjacent fullerene layers in 3D
packing are arranged in such a way that large fullerene
squares are located above and below small fullerene
squares.
Figure 7. The EPR spectra of polycrystalline pristine Cu(Et2dtc)2
(a); 1 (b), and 2 (c) at 290 K.
The EPR signal of 1 (Figure 7, b) is noticeably different
from that of pristine Cu(Et2dtc)2. According to X-ray dif-
fraction data, Cu(Et2dtc)2 has a dimeric structure in 1 as
well.[21] However, noticeable changes are observed in the
environment of CuII. Weak axial coordination of CuII to
C60 with a rather short Cu···C(C60) distance of 3.27 Å en-
hances the asymmetry of the environment of CuII. This co-
ordination directs oppositely to the axial Cu–S bond and
results in noticeable elongation of this bond from 2.844(1)
in the pristine donor to 3.030(2) Å in 1. Consequently, the
central (NCS2)2Cu fragments become more planar in 1 than
in the pristine donor. Coordination of CuII to C60 is more
favorable for planar conformation of M(Et2dtc)2, and most
Figure 6. The view of the crystal structure of 3 on the bc-plane.
[CuI(Et2dtc)]4 is a tetramer containing four CuI(Et2dtc) probably namely this coordination evokes the flattening of
units (Figure 1). CuI atoms form a slightly distorted tetra- the central (NCS2)2Cu fragments. The M···C(C60) distances
hedron with the Cu···Cu distance of 2.5698(18)– (3.587, 3.334, and 3.269 Å) decrease together with the flat-
2.6306(18) Å. Each CuI atom forms three Cu–S coordina- tening of M(Et2dtc)2 fragments in the following order: 7,
tion bonds of 2.245(3)–2.281(3) Å length. Therefore, the co- 11, and 1 (the length of axial M–S bonds are 2.599, 2.787,
ordination number of CuI is 3. Pristine CuI(Et2dtc) and and 3.030 Å, respectively).
AuI(Et2dtc) form dimers,[47,48] and for AgI(Et2dtc) hexa-
The EPR spectra of [Cu(Et2dtc)2]·(C70)2·(C6H5Cl)0.5 (2,
mers and polymers are also known.[49,50] According to the Figure 7, c), [Cu(EtMedtc)2]2·C60 (11), and [Cu(nPr2dtc)2]·
best of our knowledge, a tetrameric structure is for the first (C60)2 (13) (for spectra of 11 and 13 see supporting infor-
time observed for CuI(Et2dtc). Probably, the formation of mation) are also noticeably changed relative to those of
complexes with C60 and C70 stabilizes the tetrameric struc- pristine Cu(R2dtc)2. These changes are similar to those ob-
ture. The Cu···C(C60) and Cu···C(C70) distances (4.80 and served in the spectrum of 1 suggesting that weak coordina-
4.44 Å), as well as the vdW N and S···C(fullerene) contacts tion of CuII to fullerenes and a flattening of the central
(Table 2) are large enough to show low efficiency of the π- (NCS2)2Cu fragments can be realized in these complexes as
π interaction in 3 and 4.
well.
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D. V. Konarev et al.
FULL PAPER
Magnetic susceptibilities of 1 and 2 were measured from ters. The magnetic moment of 10 is equal to 7.78 µB per
300 down to 1.9 K and were shown to follow the Curie– formula unit at 300 K, which is close to the calculated value
Weiss law with the small negative Weiss constants of –2.5 K of 7.75 µB if two 5/2 spins contribute to magnetic suscep-
(1) and –2.0 K (2), which indicate only a weak antiferro- tibility. MnII spins interact antiferromagnetically in the
magnetic interaction between CuII centers. Axial Cu–S 150–300 K range with a large negative Weiss constant of
bonds transfer the magnetic interaction in the {Cu- –96 K and magnetic susceptibility decreases below 46 K
(Et2dtc)2}2 dimers and their elongation at the formation of (Figure 9). Such exchange interactions between MnII can
complexes with fullerenes can weaken the antiferromagnetic be realized if Mn(Et2dtc)2 forms dimers in 10 [similar to
interaction between CuII centers.
{Cd(Et2dtc)2}2 dimers in 7]. EPR data support this conclu-
The spectrum of C60 and an excess of CuI(Et2dtc) in ben- sion. The EPR signal from Mn(Et2dtc)2 in 10 remains un-
zonitrile shows that CT is realized from donor to fullerene changed qualitatively down to 4 K. No EPR signals attrib-
·– [55]
molecules in solution. To study CT in the solid state we uted to C70
were found indicating the absence of CT
measured the EPR spectra (4–290 K) and magnetic suscep- to fullerene molecules. Thus, Mn(Et2dtc)2 cannot ionize C70
tibilities of {[CuI(Et2dtc)]4}5·(C60)3·(C6H4Cl2)4 (3) and in the solid state. Similarly, MnIITPP (tetraphenylporphy-
{[CuI(Et2dtc)]4}5·(C70)3·(C6H4Cl2)4 (4) in the 2–300 K rinate) (E+/0 = –0.23 V vs. SCE)[56] forms only molecular
1/2
range. Pristine CuI(Et2dtc) is diamagnetic and EPR silent. complexes with fullerenes C60 and C70.[57]
3 and 4 are also diamagnetic with temperature-independent
diamagnetic contributions of –0.00522 and –0.00666 emu/
mol–1. Paramagnetic contributions of the Curie impurities
are only 0.23 and 1.3% for 3 and 4. According to EPR at
290 K (two narrow lines with g1 = 2.0009 and g2 = 2.0025
for 3 and one narrow line with g = 2.0019 for 4) these impu-
rities originate mainly from defects.[51] Thus, in spite of the
observation of CT in solution, both complexes are molecu-
lar ones in the solid state. Most probably, this is associated
with the formation of [CuI(Et2dtc)]4 tetramers, whose shape
is unfavorable for effective CT to fullerene molecules.
It is known that pristine MnII(Et2dtc)2 has a polymeric
structure with a distorted octahedral environment of
MnII.[39] In EPR it shows a single Lorentzian line with g =
Figure 9. Molar magnetic susceptibility of polycrystalline 10 in the
1.9–300 K range.
2.0115 and ∆H = 61.8 mT (Figure 8, a), which is character-
istic of this environment of MnII.[52] The formation of
{Mn(Et2dtc)2}2·C70 (10) results in considerable changes in
the EPR spectrum indicating noticeable modification of the
local environment of MnII. The EPR spectrum exhibits fea-
tures extending from 50 to about 500 mT (Figure 8, b).
5. IR- and UV/Visible-NIR Spectra of the Complexes
The IR spectra of 1–15 (see Supporting Information) are
Such a spectrum is typical for dinuclear MnII species[53] and a superposition of those of pristine metal dithiocarbamates,
previously a very similar EPR spectrum has been observed, fullerenes, and solvent molecules. The positions of peaks in
for example, in a dinuclear MnII complex bridged by chlo- the UV/Visible-NIR spectra of 1–15 and pristine donors are
rine atoms.[54] Magnetic susceptibility data provides evi- listed in Table 3. The absence of absorption in the NIR
dence of a strong exchange interaction between MnII cen- spectra of 1–15 at 1070 nm indicates neutral ground states
of the complexes. Pristine Cu(Et2dtc)2 has broad absorption
in the visible range with the maximum at 442 nm and a
shoulder at 660 nm (Figure 10, part 1, c). This absorption
retains in the spectra of the complexes with the maximum
at 437 nm (1, Figure 10, part 1, b) and 455 nm (2, Fig-
ure 10, part 1, a). The bands at 341 and 263 nm (1) and
230 nm (2) were ascribed to intramolecular transitions in
fullerenes.[58] The spectra of 6 (Figure 10, part 2, b) and 7
(Figure 10, part 2, a) also contain C60 absorption bands at
263 and 340 nm and a relatively weak band at 470 nm. The
latter band ascribed to intermolecular CT between neigh-
boring C60 molecules was also found in the spectra of fuller-
ene films.[59] A condition necessary for the observation of
this band in the solid-state spectra of the complexes is close
packing of fullerene molecules in the crystal.[7,60] Since C60
molecules are closely packed in 1, 7, and 6, this band can
Figure 8. The EPR spectra of polycrystalline pristine Mn(Et2dtc)2
(a) and polycrystalline 10 (b) at 290 K.
manifest itself in their spectra. However, in the spectrum
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Properties and Photoconductivity of C60 and C70 Complexes
FULL PAPER
Table 3. UV/Vis-NIR spectra of the starting compounds and 1–15.
Compounds
The bands of fullerenes
[nm]
M[d(alkyl)dtc]x
[nm]
CT bands [nm]
A (Full.)
C (D.-Full.)
C60
C70
262 s, 341 s
–, 420 s, 540 m
470 m
Cu(EtMedtc)2
Cu(Et2dtc)2
Cu(nPr2dtc)2
Ni(nPr2dtc)2
267 s, 438 s, ca. 660 w
271 s, 442s, ca. 660 w
277 s, 449s, ca. 650 w
322 s, 389 s, 606 w
263 s[a], 434 m[a], ca. 650 w
455 m[a]
1
263 s[a], 341 s
383 s, 455 m[a]
262 s, 340 m
383 s, 480 m
263 s, 334 s
261 s, 337 s
263 s, 340 s
379 s, 462 m
255 s, 332 s
388 s, 484 m
265 s[a], 337 s
261 s, 338 m
262 s[a], 341 s
266 s, 340 s,
266 s, 340 s
–
2
3
4
5
6
7
470 w
610 w
8
9
10
11
12
13
14
15
265 s[a], 443 m[a], ca. 650 w
–
262 s[a], 434 m,[a] ca. 615 w
ca. 605 w[a]
434 m[a]
450 w
450 w
900 w
ca. 770 w[a]
650 w
[a] The bands overlap.
of 1 it is closed by absorption of Cu(Et2dtc)2. A similar 6. Photoconductivity in C60 and C70 Complexes with
interfullerene CT band was reported for pristine C70 at Cu(Et2dtc)2 and Cd(Et2dtc)2 (1, 2, 7, and 8)
550 nm,[59] and it can also contribute to broad absorption
of 2 at 500–600 nm (Figure 10, part 1, a).
According to the IR- and EPR data, 1, 2, 7, and 8 are
molecular complexes without CT in the ground state. The
crystals of 1, 2, and 7 have low “dark” conductivity σ Ϸ
10–10 to 10–11 S·cm–1. The photoexcitation of single crystals
of the complexes by white light from a 150 W halogen tube
with 1012 to 1014 photons/cm2·s intensity results in a 20–50-
fold increase in the photocurrent in 1, two orders of magni-
tude in 2, and three orders of magnitude in 7. These values
remain unchanged under the illumination of the crystals for
104 s and are completely reproducible. The crystals of 8 do
not show a noticeable increase in photocurrent at photoex-
citation.
Photoconductivity spectra of the complexes are shown in
Figure 11. Photoconductivity has maxima at 470 nm for 1,
450–650 nm for 2, and about 660 nm for 7. The comparison
of the photoconductivity spectra of 1, 2, and 7 with their
absorption spectra allows one to suppose the mechanisms of
free charge carrier generation. In 1 and 2 the main contri-
bution is given by the photoexcitation of Cu(Et2dtc)2 (440
and 660 nm) as well as interfullerene CT between neighbor-
ing C60 or C70 molecules (470 nm for 1 and 550 nm for 2,
The spectrum of 7 additionally contains a broad weak
band at 610 nm (Figure 10, part 2, a). Because C60 and
Cd(Et2dtc)2 do not absorb noticeably in this range, it can
be attributed to intermolecular CT from Cd(Et2dtc)2 to C60.
The observation of this band is possible due to favorable π-
π interaction between Cd(Et2dtc)2 and C60 molecules (Fig-
ure 2, c). CT bands are absent in the spectra of 6 (Figure 10,
part 2, b) and 1–5, 8–12 (Supporting Information) indicat-
ing worse conditions for the π-π interaction between non-
planar MII(R2dtc)x and fullerenes. Absorption at 600–
700 nm in the spectra of 1, 2, and 11 was attributed mainly
to Cu(R2dtc)2 (a shoulder at 660 nm).
Several processes can occur at photoexcitation of 1, 2,
and 7 in the visible range. In 1 and 2 mainly photoexcitation
of CuII(Et2dtc)2 (437 and 660 nm) is realized together with
a minor contribution of intermolecular CT between neigh-
boring C60 and C70 molecules (470 and 550 nm, respec-
tively), whereas in 7 intermolecular CT from Cd(Et2dtc)2 to
C60 molecules (610 nm) and between C60 molecules
(470 nm) is mainly realized.
The absorption spectra of 13 and pristine Cu(nPr2dtc)2 Figure 11, a and b). The major contribution is given in 7 by
are shown in part 3 of Figure 10. Additionally to absorp- CT from the Cd(Et2dtc)2 to the C60 molecule (610 nm) with
tion of Cu(nPr2dtc)2 in the visible range (Figure 10, part 3, a small contribution of interfullerene CT between neighbor-
a, and Table 3), the intense band with the maximum at ing C60 molecules (470 nm) (Figure 11, c). In spite of similar
900 nm (Figure 10, part 3, a) was attributed to CT from crystal structures, the mechanisms of free charge carrier gen-
the Cu(nPr2dtc)2 to the C60 molecules. Similar bands are eration are different in 1 and 7. In 1 Cu(Et2dtc)2 has intense
observed in the spectra of 14 and 15. Therefore, planar absorption in the visible range, whereas Cd(Et2dtc)2 is trans-
M(nPr2dtc)2 have better conditions for the π-π interaction parent in 7 in this range. However, steric compatibility of the
with fullerenes than nonplanar M[(Et, Me)2dtc]2.
Cd(Et2dtc)2 and C60 molecules (Figure 2, c) provides better
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D. V. Konarev et al.
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Figure 11. Photoconductivity spectra of the crystals of 1 (a), 2 (b),
and 7 (c). The positions of the main peaks in the spectra are shown
by dashed lines.
Figure 10. The UV/Visible-NIR spectra of: (1) 2 (a); 1 (b); and
pristine Cu(Et2dtc)2 (c). (2) 7 (a); and 6 (b). (3) 13 (a); and pristine
Cu(nPr2dtc)2 (b) in KBr pellets.
with doublet paramagnetic species may lead either to spin-
independent triplet scattering or quenching. During
quenching a transition from the initial spin state, which is
a mixture of a doublet and a quartet, to a purely doublet
final state takes place:
conditions for the π-π interaction and correspondingly for
intermolecular CT in 7 than in 1. Complex 8 has no CT
band in the visible range and as a result photoconductivity
was not found in this complex.
Photoconductivity of 1 and 7 is sensitive to weak mag-
netic field (MF) with B0 Ͻ 0.5 T (Figure 12). A negative
MF effect on photoconductivity is because of the reaction
involving triplet CT excitons and paramagnetic centers.
The rate constant kL of the transition from each of the
This interaction releases charges from deep-seated traps and six L-th initial spin states of an intermediate complex to a
increases photocurrent. A collision of triplet CT-excitons final one depends on the amplitude of the doublet compo-
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Properties and Photoconductivity of C60 and C70 Complexes
FULL PAPER
nomeric conformations for Zn(EtMedtc)2 and Zn(Et2dtc)2
and tetrameric {CuI(Et2dtc)}4 were for the first time found
for these metal dithiocarbamates.
Butterfly-shaped [M{(Me, Et)2dtc}2]2 dimers (M = Cu
and Cd) form layered structures in 1, 7, and 11, where the
packing of C60 layers varies from a square to hexagonal
one. The dimeric structure of dithiocarbamates provides a
characteristic 1:2 composition of the complexes {Fullerene/
M[(Et, Me)dtc]2}. Complexes 8–10 have the same composi-
tion, and M(R2dtc)2 can have similar dimeric structures in
these complexes. This supposition was justified for 10 by
magnetic data. Cd(Et2dtc)2 has geometry conforming well
to the spherical shape of fullerene molecules and shows
high ability to nearly quantitatively precipitate C60 and C70
complexes from solutions. A similar ability was found for
Mn(Et2dtc)2 and Fe(Et2dtc)2. Monomeric Ni(nPr2dtc)2 and
Pt(nPr2dtc)2 with square planar conformation of the central
(NCS2)2M fragment form 12 and 13 with a 2:1 composition
[Fullerene/M(nPr2dtc)2]. Complexes 2 and 13 have the same
composition and the formation of Cu(Et2dtc)2 and
Cu(nPr2dtc)2 monomers can be supposed for these com-
plexes as well especially because pristine Cu(R2dtc)2 can
adopt a square planar conformation.[43,44] However, X-ray
diffraction data are needed to prove this supposition. Non-
planar tetrahedral Zn(EtMedtc)2 and Zn(Et2dtc)2 provide
3D packing of fullerenes with their tetrahedral and hexa-
hedral arrangements. Bulky [CuI(Et2dtc)]4 promotes an is-
land motif in fullerene packing.
Figure 12. Magnetic field (B0, T) dependence of photocurrent (I,
%) in 1 (a) and 7 (b).
nent therein. The total rate of exciton quenching by para-
magnetic impurity is:
Using M(Et2dtc)x with different donor ability (the
strongest donors contain M = CuI, CoII, VII, and MnII) we
found that CuI(R2dtc), Co(R2dtc)2, and V(R2dtc)2 reduce
C60 in benzonitrile. However, among these strong donors
only fullerene complexes with Mn(Et2dtc)2 and CuI(Et2dtc)
were obtained as crystals and no CT to fullerene molecules
was found in them. The EPR spectra of paramagnetic
Cu(R2dtc)2 and Mn(Et2dtc)2 noticeably change at the com-
plex formation with fullerenes most probably due to
changes in the environment of MII. The EPR spectra of 1,
2, 11, and 13 are noticeably modified relative to those of
pristine Cu(R2dtc)2. Such changes can be a result of ad-
ditional weak coordination of CuII to C60 and the flattening
of the central (NCS2)2Cu fragment. The changes in the
EPR spectrum of Mn(Et2dtc)2 at the formation of 10 are
most probably evoked by the transition from a polymeric
structure of pristine Mn(Et2dtc)2 with an octahedral envi-
ronment of MnII to the formation in 10 of {Mn(Et2dtc)2}2
dimers, in which strong antiferromagnetic exchange interac-
where k1 and k–1 are rate constants of collision and back
scattering, respectively. The value of Q has a maximum,
when a doublet component is uniformly distributed over all
six substates, the minimum of Q is attained at the complete
separation of a doublet and a quartet. The quenching rate
is maximal in ZMF. With the application of an external
MF, the doublet component concentrates on four states and
the value of Q decreases together with the rate of dissoci-
ation of CT excitons and, consequently, a number of free
charge carriers. A similar negative MF dependence was
found in anthracene.[61]
Conclusions
We studied the formation of the complexes between me- tion between MnII centers is possible.
tal dialkyldithiocarbamates, M(R2dtc)x with R = EtMe
The spectra of the complexes in the visible and NIR ran-
(CuII, ZnII); Et (CuII, CuI, AgI, ZnII, CdII, HgII, MnII, FeII, ges indicate their neutral ground state. Cu(R2dtc)2 (1, 2, 11,
CoII, VII, NiII, and PtII); nPr (CuII, CuI, ZnII, CdII, NiII, and 13) and Ni(nPr2dtc)2 (14) absorb in the visible range,
and PtII) and fullerenes C60 and C70. It was shown that whereas other M(R2dtc)2 are nearly transparent in this
M(R2dtc)x co-crystallize with fullerenes C60 and C70 to range. In addition to the bands associated with intramo-
form complexes of different structures and compositions lecular transitions in fullerenes and M(R2dtc)x, the bands
(1–15). Pristine M(R2dtc)x (R = Et, nPr) have a large vari- associated with intermolecular CT between neighboring
ety of molecular structures in fullerene complexes, which fullerene molecules (at 470 nm for C60 and at 550 nm for
can be square planar or tetrahedral monomers, strongly C70)[59] and CT from M(R2dtc)2 to fullerene molecules are
and weakly bound dimers and tetramers. Tetrahedral mo- observed. The latter CT bands are observed only in the
Eur. J. Inorg. Chem. 2006, 1881–1895
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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1891

D. V. Konarev et al.
FULL PAPER
(100 mg), CoBr2 (150 mg), VCl2 (100 mg), FeBr2 (150 mg), and
MnI2 (150 mg) and x [x = 1 (CuI) or 2 (other metals)] molar equiv-
alents of Na(Et2dtc) in 10 mL of degassed acetonitrile over 4 h in
a glove box. M(R2dtc)x were precipitated from acetonitrile as light
yellow (CuI and MnII), light pink (FeII), dark green-brown (CoII),
and light brown (VII) powders together with NaCl(Br, I). The pre-
cipitates were washed with acetonitrile (3 mL) and dried.
NaCl(Br, I) as well as possible admixtures of unreacted MCl(Br, I)x
and Na(Et2dtc) were separated from M(R2dtc)x at a stage of com-
plex formation with fullerene because of their insolubility in o-
spectra of 7 and the complexes with planar M(nPr2dtc)2
(13–15). The other complexes demonstrate either weak or
no CT bands indicating worse conditions for the π-π inter-
action between fullerenes and nonplanar M(R2dtc)x. In ac-
cordance with the neutral ground state, the crystals of 1, 2,
and 7 show low dark conductivity of 10–10 to 10–11 S·cm–1.
The illumination of the crystals by white light with 1012 to
1014 photons/cm2·s intensity results in up to a 103 increase
in photocurrent. The photoconductivity spectra exhibit
maxima at 470, 450–650, and 660 nm for 1, 2, and 7, respec- dichlorobenzene (C6H4Cl2). Air-stable M(R2dtc)2 (R = EtMe, M =
CuII, and ZnII; R = Et, M = CuII, ZnII, CdII, HgII, AgI, NiII, and
tively. Three processes generate free charge carriers in the
complexes. Photoexcitation of Cu(Et2dtc)2 contributes to
PtII; R = nPr, M = CuII, ZnII, CdII, NiII, and PtII) were obtained
in aqueous solution from CuBr2, ZnCl2, CdBr2·4H2O, Hg(NO3)2·
photoconductivity of 1 and 2 since this donor has intense
H2O, AgNO3, NiCl2, PtCl2, and Na(R2dtc).[43] M(R2dtc)2 were dis-
absorption in the visible range. A similar mechanism was
solved in hot chlorobenzene (C6H5Cl), filtered off from NaCl,
observed in Bz4BTPE·C60 {Bz4BTPE: tetrabenzo[1,2-
NaBr, or NaNO3 and the solvent was removed to dryness on a
bis(4H-thiopyran-4-ylidene)ethane]},[62] and conjugated
rotary evaporator to yield pure M(R2dtc)2 with satisfactory elemen-
tal analyses (50–80% yield). C60 of 99.98% purity and C70 of 99.0%
purity were used from MTR Ltd. Solvents were purified under ar-
gon. C6H4Cl2 and C6H5Cl were distilled over CaH2. Hexane and
polymer-fullerene composites.[63] CT from donor to fuller-
ene molecules contributes to photoconductivity of the com-
plexes with relatively intense CT bands in the visible-NIR
range:
7 and TBPDA·(C60)2 (N,N,NЈ,NЈ-tetrabenzyl-p- benzonitrile (C6H5CN) were distilled over Na/benzophenone. For
the synthesis of air-sensitive M(R2dtc)x (R = Et, M = CuI, CoII,
VII, FeII, and MnII; R = nPr, M = CuI) and the preparation of the
fullerene complexes, solvents were degassed and stored in a
MBraun 150B-G glove box with a controlled atmosphere with con-
tents of H2O and O2 of less than 1 ppm. The crystals of 3, 4, and
10 were stored in a glove box and were sealed in 2-mm quartz tubes
for EPR and SQUID measurements under 10–5 Torr. KBr pellets
for IR- and UV/Visible-NIR measurements were prepared in a
glove box.
phenylenediamine).[19] Interfullerene CT between neighbor-
ing fullerene molecules also contributes to photoconductiv-
ity in 1 and 7 as well as in pure fullerene crystals[64] and
films.[59] Common peculiarity of the C60 complexes showing
photoconductivity is a layered arrangement of fullerene and
donor molecules in a crystal, which allow the movement of
photogenerated carriers through the crystal. Weak MF with
B0 Ͻ 0.5 T differently affects photoconductivity of fullerene
complexes. We found negative (1 and 7) and positive
(Bz4BTPE·C60)[64] MF dependences as well as the field de-
Synthesis: The composition of 1–5, 7–11, and 13–15 was deter-
mined from the elemental analysis (Table 1) and was justified for
1, 3, 4, 6, 7, 11, and 12 by X-ray diffraction on a single crystal.
pendence with sign inversion at 0.3 T [TBPDA·(C60)2].[19]
A
variety of dependences indicates that the interaction of MF
with photogenerated excitons can be different in fullerene
complexes depending on the donor used. The mechanisms
of the effects of MF on photoconductivity involve triplet
CT excitons and paramagnetic centers[61] or the population
of a triplet state from a singlet one in MF.[65] Thus, fullerene
complexes with M{Et2dtc}2 and other M{R2dtc}x may be
a new wide family of photoactive compounds. A study of
the photophysical properties of these complexes is now in
progress.
The crystals of 1, 2, 5, 6, 9, and 11–15 were obtained by a slow
evaporation of chlorobenzene solution (15 mL) containing C60
(25 mg, 0.0347 mmol) and two molar equivalents of M(R2dtc)x
(0.06940 mmol) over 1 week. The crystals precipitated were washed
with an excess of acetone (50–80% yield). The shapes of the crystals
are presented in Table 1.
The crystals of 3 and 4 were obtained under anaerobic conditions
by a slow diffusion of hexane (20 mL) in C6H4Cl2 solution (20 mL)
containing C60 (25 mg, 0.0347 mmol) (3) or C70 (20 mg,
0.0238 mmol) (4) and a fourfold molar excess of CuI(Et2dtc) in a
glass tube of 45 mL volume with a ground glass plug. After
1 month large black prisms of 3 and 4 were precipitated on the wall
of the tube (up to 0.5×0.5×0.8 mm3 size). The solvent was de-
canted and the crystals were washed with hexane (50–60% yield).
Experimental Section
Materials: Sodium diethyldithiocarbamate trihydrate, [Na(Et2dtc)·
3H2O], was purchased from Aldrich and recrystallized from an ace-
tonitrile/benzene mixture. Sodium ethylmethyldithiocarbamate,
Cd(Et2dtc)2, Mn(Et2dtc)2, and Fe(Et2dtc)2 nearly quantitatively
precipitate C60 and C70 from different solvents (C6H6, C6H5Cl, and
C6H4Cl2). Because of this, the crystals of 7 and 8 were obtained by
the diffusion of a benzene solution (20 mL) of C60 (20 mg,
0.02775 mmol) (7) or C70 (20 mg, 0.0238 mmol) (8) in CHCl3 solu-
tion (20 mL) containing a twofold molar excess of Cd(Et2dtc)2. The
crystals precipitated on the wall of the tube after 1 month. They
were washed with acetone (70–90% yield).
Na(EtMedtc),
and
sodium
di(n-propyl)dithiocarbamate,
Na(nPr2dtc), were obtained by the reported procedure.[43] Carbon
disulfide (3.1 mL, 0.052 mol) and sodium hydroxide (50% aqueous
solution, 4 mL) were added to a stirred solution of R2NH
(0.05 mol) (R2NH=EtMeNH, Aldrich, and nPr2NH, Wako) in eth-
anol (5 mL) at T Ͻ 4 °C (ice bath). After stirring for 4–6 h at T Ͻ
4 °C Na(EtMedtc) precipitated as white crystals. Na(nPr2dtc) was
obtained by the evaporation of an ethanol/water solution without
heating. Pure Na(R2dtc) were obtained by recrystallization from
acetonitrile/benzene mixtures (50–80% yields). Air-sensitive
The crystals of 10 were obtained similarly under anaerobic condi-
tions by the diffusion of benzene solution (20 mL) of C70 (20 mg,
0.0238 mmol) (8) into C6H4Cl2 containing a twofold molar excess
M(R2dtc)x compounds (R = Et, M = CuI, CoII, VII, FeII, and MnII; of Mn(Et2dtc)2. The crystals precipitated on the wall of the tube
R = nPr, M = CuI) were obtained by stirring anhydrous CuCl
after 1 month. They were washed with hexane (70% yield).
1892
www.eurjic.org
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2006, 1881–1895

Properties and Photoconductivity of C60 and C70 Complexes
FULL PAPER
Table 4. X-ray diffraction data for 1, 3, 4, 6, 7, 11, and 12.
1[21]
3
4
Structural formula
Empirical formula
[Cu(Et2dtc)2]2·C60
C80H40Cu2N4S8
1440.72
{[CuI(Et2dtc)]4}5·(C60)3·(C6H4Cl2)4 {[CuI(Et2dtc)]4}5·(C70)3·(C6H4Cl2)4
C76H54Cl2Cu5N5S10
C83.50H54Cl2Cu5N5S10
Mr [g·mol–1
]
1746.41
1836.52
Crystal shape and color
Size [mm×mm×mm]
Crystal system
Space group
a [Å]
b [Å]
c [Å]
α [°]
black hexagonal prisms
0.40×0.30×0.25
monoclinic
P21/c
16.1948(8)
10.2552(5)
17.2192(9)
90
black cubes
0.50×0.40×0.40
cubic
black cubes
0.40×0.30×0.30
cubic
¯
¯
Pn3n
Pn3n
43.7822(4)
43.7822(4)
43.7822(4)
90
44.2911(3)
44.2911(3)
44.2911(3)
90
β [°]
102.504(2)
90
2791.9(2)
2
1.714
1.12
90
90
90
90
γ [°]
V [Å3]
Z
83925.3(13)
48
1.655
1.921
42240
no correction
0.51/0.45
90(2)
86885.9(10)
48
1.685
ρcalc [g/cm3]
µ [mm–1
F(000)
]
1.860
44592
1468
Absorption correction
Max./min. transmission
T [K]
no correction
0.77/0.66
90(2)
SADABS[66]
0.60/0.52
90(1)
Max. 2θ [°]
54.12
50.04
50.04
Reflections measured
Unique reflections
Rint
Parameters, restraints
Reflections [Fo Ͼ 2σ(Fo)] 4983
25977
5683
0.036
425, 0
524031
12379
0.0429
450, 0
9398
690665
12798
0.0637
458, 0
8774
R1 [Fo Ͼ 2σ(Fo)]
wR2 (all data)[a]
a
0.0404
0.0984
0.2904
0.1060
2219.48
1.132
0.0935
0.3181
0.1330
2964.08
1.054
0.1064
0.0341
8.2311
1.082
b
G.O.F.
Restr. G.O.F.
CCDC number
1.082
260289
1.132
286142
1.054
286143
6
7
11
12
Structural formula
Empirical formula
Zn(Et2dtc)2·C60·(C6H5Cl)0.5·(C6H6)0.5
C76H25.5Cl0.5N2S4Zn
1177.82
black parallelepipeds
0.33×0.20×0.20
[Cd(Et2dtc)2]2·C60
C80H40Cd2N4S8
1538.44
brown rhombus
0.40×0.30×0.10
monoclinic
P21/c
16.1712(13)
16.9680(12)
10.5355(8)
90
99.857(2)
90
2848.2(4)
2
1.794
1.098
[Cu(EtMedtc)2]2·C60 [Zn(EtMedtc)2]3·(C60 2
)
C76H32Cu2N4S8
1384.62
black rhombus
0.42×0.38×0.10
monoclinic
P21
C144H54N6S12Zn3
2442.71
black rhombus
0.40×0.30×0.20
orthorhombic
Pn21a
Mr [g·mol–1
]
Crystal shape and color
Size [mm×mm×mm]
Crystal system
Space group
a [Å]
b [Å]
c [Å]
α [°]
β [°]
triclinic
¯
P1
10.3762(5)
15.1717(7)
17.0002(8)
115.893(1)
91.555(1)
102.938(1)
2322.53(19)
2
16.0626(4)
10.0196(3)
17.0653(5)
90
20.815(5)
26.072(6)
17.128(4)
90
100.9490(13)
90
90
90
γ [°]
V [Å3]
Z
2696.51(13)
2
9298.88(12)
4
ρcalc [g/cm3]
1.684
0.797
1196
1.705
1.746
µ [mm–1
F(000)
]
1.156
1.109
1544
1404
4944
Absorption correction
Max./min. transmission
T [K]
SADABS[66]
0.86/0.78
90(1)
SADABS[66]
0.90/0.72
123(2)
no correction
0.89/0.64
100(2)
no correction
0.81/0.66
100(2)
Max. 2θ [°]
58.0
51.88
54.96
51.48
Reflections measured
Unique reflections
Rint
25011
7276
0.03
13023
3602
0.0333
20222
11660
42780
17592
Parameters, restraints
Reflections [Fo Ͼ 2σ(Fo)] 6312
R1 [Fo Ͼ 2σ(Fo)]
wR2 (all data)[a]
a
724, 10
424, 423
3100
0.0358
0.085
0.040
812, 0
10282
0.0381
0.0902
0.0294
3.4011
1.033
2393, 11252
8450
0.042
0.1038
0.3023
0.1956
0.0000
0.954
0.1177
0.0582
5.0135
1.042
b
5.096
1.055
G.O.F.
Restr. G.O.F.
CCDC number
1.056
286144
1.006
288291
1.033
288292
0.758
288293
[a] (a) w = 1/[σ2(Fo2) + (aP)2 + bP], P = [max(Fo2,0) + 2 Fc ]/3.
2
Eur. J. Inorg. Chem. 2006, 1881–1895
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1893

D. V. Konarev et al.
FULL PAPER
The C60 complexes with Mn(Et2dtc)2 and Fe(Et2dtc)2 were also
obtained as powders by mixing C60 (25 mg, 0.0347 mmol) and a
twofold molar excess of M(Et2dtc)2 in C6H4Cl2 (20 mL) on heating
(60 °C, 2 h). The hot solution was filtered, cooled down to room
temperature, and stood overnight. The solution became colorless,
and a light brown polycrystalline precipitate was formed. However,
in contrast to crystals of 10, powdered samples did not show rea-
sonable elemental analyses probably because of the high air-sensi-
tivity of the complexes. Indeed, Mn(Et2dtc)2 and Fe(Et2dtc)2 are
extremely air-sensitive and oxidize in a few seconds in air.
(EtMedtc)2 and Cu(nPr2dtc)2 and complexes 11 and 13 (Tables S1
and S2, Figures S1–S7).
Acknowledgments
The work was supported by the RFBR grants N 03-03-32699-a and
03-03-20003 BNTS-a, the Russian Science Support Foundation,
Rosnauka grant 2006-RI-19.0/001/058, and partly by Grant-in-Aid
Scientific Research from the Ministry of Education, Culture,
Sports, Science and Technology, Japan (152005019, 21st Century
COE, and Elements Science 12CE2005). We thank Dr. E.I. Yud-
anova for help with the EPR investigations.
We tried to crystallize the C60 complexes with Co(Et2dtc)2 and
V(Et2dtc)2. C60 (25 mg, 0.0347 mmol) and a twofold molar excess
of M(Et2dtc)2 were dissolved in C6H4Cl2 (20 mL) on stirring at
60 °C for 4 h. The hot solution was filtered, cooled down to room
temperature, and filtered in a glass tube of 45 mL volume with a
ground glass plug. Slow diffusion of hexane (20 mL) was carried
out under anaerobic conditions. However, only black powder with-
out crystals formed after 2 months.
[1] A. L. Balch, M. M. Olmstead, Chem. Rev. 1998, 98, 2123–2165.
[2] D. V. Konarev, R. N. Lyubovskaya, Russ. Chem. Rev. 1999, 68,
19–38.
[3] C. A. Reed, R. D. Bolskar, Chem. Rev. 2000, 100, 1075–1120.
[4] A. L. Litvinov, D. V. Konarev, A. Y. Kovalevsky, I. S. Neretin,
Y. L. Slovokhotov, P. Coppens, R. N. Lyubovskaya,
CrystEngComm 2002, 4, 618–622.
[5] P.-M. Allemand, K. C. Khemani, A. Koch, F. Wudl, K.
Holczer, S. Donovan, G. Grüner, J. D. Thompson, Science
1991, 253, 301–303.
[6] D. V. Konarev, R. N. Lyubovskaya, N. V. Drichko, E. I. Yu-
danova, Y. M. Shul’ga, A. L. Litvinov, V. N. Semkin, B. P.
Tarasov, J. Mater. Chem. 2000, 10, 803–818.
[7] D. V. Konarev, A. Y. Kovalevsky, A. L. Litvinov, N. V. Drichko,
B. P. Tarasov, P. Coppens, R. N. Lyubovskaya, J. Solid State
Chem. 2002, 168, 474–485.
[8] G. Saito, T. Teramoto, A. Otsuka, Y. Sugita, T. Ban, M. Kusu-
noki, K. Sakaguchi, Synth. Met. 1994, 64, 359–368.
[9] 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.
[10] P. D. W. Boyd, M. C. Hodgson, C. E. F. Rickard, A. G. Oliver,
L. Chaker, P. J. Brothers, R. D. Bolskar, F. S. Tham, C. A.
Reed, J. Am. Chem. Soc. 1999, 121, 10487–10495.
[11] D. V. Konarev, I. S. Neretin, Y. L. Slovokhotov, E. I. Yu-
danova, N. V. Drichko, Y. M. Shul’ga, B. P. Tarasov, L. L. Gu-
manov, A. S. Batsanov, J. A. K. Howard, R. N. Lyubovskaya,
Chem. Eur. J. 2001, 7, 2605–2616.
[12] D. H. Hochmuth, S. L. J. Michel, A. J. P. White, D. J. Williams,
A. G. M. Barrett, B. M. Hoffman, Eur. J. Inorg. Chem. 2000,
593–596.
[13] J. D. Crane, P. B. Hitchcock, H. W. Kroto, R. Taylor, D. R. M.
Walton, J. Chem. Soc. Chem. Commun. 1992, 1764–1765.
[14] W. C. Wan, X. Liu, G. M. Sweeney, W. E. Broderick, J. Am.
Chem. Soc. 1995, 117, 9580–9581.
[15] A. Hönnerscheid, L. van Wüllen, M. Jansen, J. Rahmer, M.
Mehring, J. Chem. Phys. 2001, 115, 7161–7165.
[16] D. V. Konarev, S. S. Khasanov, A. Otsuka, G. Saito, J. Am.
Chem. Soc. 2002, 124, 8520–8521.
[17] D. V. Konarev, S. S. Khasanov, G. Saito, A. Otsuka, Y. Yo-
shida, R. N. Lyubovskaya, J. Am. Chem. Soc. 2003, 125,
10074–10083.
[18] D. Y. Sun, C. A. Reed, Chem. Commun. 2000, 2391–2392.
[19] D. V. Lopatin, V. V. Rodaev, A. V. Umrikhin, D. V. Konarev,
A. L. Litvinov, R. N. Lyubovskaya, J. Mater. Chem. 2005, 15,
657–660.
[20] D. V. Konarev, G. Zerza, M. C. Scharber, N. S. Sariciftci, R. N.
Lyubovskaya, Mol. Crys. Liq. Crys. 2005, 427, 315–333.
[21] D. V. Konarev, A. Y. Kovalevsky, D. V. Lopatin, V. V. Rodaev,
A. V. Umrikhin, E. I. Yudanova, P. Coppens, R. N. Lyubov-
skaya, G. Saito, Dalton Trans. 2005, 1821–1825.
General: UV/Visible-NIR spectra were measured with a Shimadzu-
3100 spectrometer in the 240–2600 nm range. FT-IR spectra were
measured in KBr pellets with a Perkin–Elmer 1000 Series spectrom-
eter (400–7800 cm–1). A Quantum Design MPMS-XL SQUID
magnetometer was used to measure static magnetic susceptibilities
of 1–4 and 10 from 1.9 up to 300 K. A sample holder contribution
and core temperature independent diamagnetic susceptibility (χ0)
were subtracted from the experimental values. The values of Θ, χ0
were calculated using the appropriate formula: χM = C/(T – Θ) +
χ0. EPR spectra were recorded for 1, 2, 11, and 13 at room temp.
and for 3, 4, and 10 from RT down to 4 K with a JEOL JES-TE
200 X-band ESR spectrometer equipped with a JEOL ES-CT470
cryostat. Photoconductivity of 1, 2, 7, and 8 was excited using a
white light halogen tube with 1012–1014 photons/cm2s intensity. To
record the spectra of photoconductivity the light beam of a xenon
lamp was transmitted through a high-aperture monochromator. A
static magnetic field with the induction up to 1 T was generated by
an electromagnet of a Radiopan SE/X 2547 ESR spectrometer.
X-ray Crystal Structure Determination: X-ray diffraction data for
1, 3, 4, 6, 7, 11, and 12 were collected with a Bruker SMART1000
CCD diffractometer installed at a rotating anode source (Mo-Kα
radiation, λ = 0.71073 Å), and equipped with an Oxford Cryosys-
tems nitrogen gas-flow apparatus. The data were collected by the
rotation method with 0.3° frame-width (ω scan) and 10 s exposure
time per frame. Four sets of data (600 frames in each set) were
collected, nominally covering half of the reciprocal space. The data
were integrated, scaled, sorted and averaged using the SMART
software package.[66] The structures were solved by the direct meth-
ods using SHELXTL NT Version 5.10.[67] The structure was re-
fined by full-matrix least-squares against F2. The details of the X-
ray crystal structure analysis for 1, 3, 4, 6, 7, 11, and 12 including
CCDC numbers for the structures are given in Table 4. Non-hydro-
gen atoms were refined in the anisotropic approximation. Positions
of hydrogen atoms were calculated geometrically. Subsequently, the
positions of H-atoms were refined by the “riding” model with Uiso
= 1.2Ueq of the connected non-hydrogen atom or as ideal CH3
groups with Uiso = 1.5Ueq. The supplementary crystallographic
data for this paper can be obtained free of charge from The Cam-
bridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
[22] D. V. Konarev, A. Y. Kovalevsky, A. Otsuka, G. Saito, R. N.
Lyubovskaya, Inorg. Chem. 2005, 44, 9547–9556.
[23] A. Bonamiko, G. Dessy, C. Mariani, A. Vaciago, L. Zam-
bonelli, Acta Crystallogr. 1965, 19, 619–626.
Supporting Information (for details see the footnote on the first
page of this article): IR-data, UV/Vis-NIR spectra of pristine do-
nors and complexes 1–15, and EPR spectra of pristine Cu-
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Eur. J. Inorg. Chem. 2006, 1881–1895

Properties and Photoconductivity of C60 and C70 Complexes
FULL PAPER
[24] A. Z. Amanov, G. A. Kukina, M. A. Porai-Koshits, Dokl.
Akad. Nauk Az. SSR 1977, 33, 23–26.
[49]
H. Yamaguchi, A. Kido, T. Uechi, K. Yasukouchi, Bull. Chem.
Soc. Jpn. 1976, 49, 1271–1276.
[25] J. Lokaj, V. Vrabel, E. Kello, Chem. Zvesti 1984, 38, 313–317.
[26] M.-L. Riekkola, T. Pakkanen, L. Niinisto, Acta Chem. Scand.
Ser. A 1983, 37, 807–812.
[27] P. W. G. Newnan, A. H. White, J. Chem. Soc. Dalton Trans.
1972, 2239–2243.
[28] M. Decoster, F. Conan, J. E. Guerchais, Y. Le Mest, J.
Sala Pala, J. C. Jeffery, E. Faulques, A. Leblanc, P. Molinié,
Polyhedron 1995, 14, 1741–1750.
[29] F. Conan, J. Sala Pala, M.-T. Garland, R. Baggio, Inorg. Chim.
Acta 1998, 278, 108–112.
[30] H. L. M. Van Gaal, J. G. M. Van der Linden, Coord. Chem.
Rev. 1982, 47, 41–54.
[31] H. H. Wickman, A. M. Trozzolo, H. J. Williams, G. W. Hull,
F. R. Merritt, Phys. Rev. 1967, 155, 563–566.
[32] D. Dubois, K. M. Kadish, S. Flanagan, R. E. Haufler, L. P. F.
Chibante, L. J. Wilson, J. Am. Chem. Soc. 1991, 113, 4364–
4366.
[50]
[51]
R. Hesse, L. Nilson, Acta Chem. Scand. 1969, 23, 825–828.
M. D. Pace, T. C. Christidis, J. J. Yin, J. Milliken, J. Phys.
Chem. 1992, 96, 6855–6858.
R. D. Dowsing, B. Nieuwenhuijse, J. Reedijk, Inorg. Chim. Acta
1971, 5, 301–308.
S. V. Khangulov, A. J. Dessiki, V. V. Barynin, D. E. Ass, G. C.
Dismukes, Biochemistry 1995, 34, 2015–2025.
I. Romero, M.-N. Collomb, A. Deronyier, A. Llobet, E. Perret,
J. Pèkaut, L. Le Pare, J.-M. Latour, Eur. J. Inorg. Chem. 2001,
69–72.
A. Pénicaud, A. P. Pérez-Benítez, R. Escudero, C. Coulon, So-
lid State Commun. 1995, 96, 147–150.
K. Nagai, T. Iyoda, K. Hashimoto, A. Fujishima, Perspectives
in Organic-Inorganic Hybrid Solids, Abstr. Int. Conf., Nagoya,
Japan, 1996, p. 118.
E. I. Yudanova, D. V. Konarev, L. L. Gumanov, R. N. Lyubov-
skaya, Russ. Chem. Bull. 1999, 48, 718–721.
M. S. Dresselhaus, G. Dresselhaus, P. C. Eklund, Science of
Fullerenes and Carbon Nanotubes, Academic Press, San Diego,
1996.
[52]
[53]
[54]
[55]
[56]
[57]
[58]
[33] M. Bonamico, G. Mazzone, A. Vaciago, L. Zambonelli, Acta
Crystallogr. 1965, 19, 898–909.
[34] N. Sreehari, B. Varghese, P. T. Manoharan, Inorg. Chem. 1990,
29, 4011–4015.
[35] H. Miyamae, M. Ito, H. Iwasaki, Acta Crystallogr. Sect. B
1979, 35, 1480–1482.
[36] A. Domenicano, L. Torelli, A. Vaciago, L. Zambonelli, J.
Chem. Soc. A 1968, 1351–1361.
[37] F. Jian, Z. Wang, Z. Bai, X. You, H.-K. Fun, K. Chinnakali,
J. Chem. Crystallogr. 1999, 29, 227–231.
[38] D. A. Ileperuma, R. D. Feltham, Inorg. Chem. 1975, 14, 3042–
3045.
[59] S. Kazaoui, N. Minami, Y. Tanabe, H. J. Byrne, A. Eilmes, P.
Petelenz, Phys. Rev. B 1998, 58, 7689–7700.
[60] D. V. Konarev, N. V. Drichko, R. N. Lyubovskaya, Y. M.
Shul’ga, A. L. Litvinov, V. N. Semkin, Y. A. Dubitsky, A. Za-
opo, J. Mol. Struct. 2000, 526, 25–29.
[61] V. Ern, R. E. Merrifield, Phys. Rev. Lett. 1968, 21, 609–611.
[62] D. V. Konarev, S. S. Khasanov, G. Saito, D. V. Lopatin, V. V.
Rodaev, A. V. Umrikhin, A. L. Litvinov, R. N. Lyubovskaya,
J. Phys. Chem. Solids 2005, 66, 711–715.
[63] N. S. Sariciftci, A. J. Heeger in Handbook of Organic Conduc-
tive Molecules and Polymers (Ed.: H. S. Nalwa), Wiley & Sons
Ltd., 1997, vol. 1, p. 414.
[39] M. Ciampolini, C. Mengozzi, P. Orioli, J. Chem. Soc. Dalton
Trans. 1975, 2051–2054.
[40] P. C. Healy, A. H. White, J. Chem. Soc. Dalton Trans. 1973,
284–287.
[41] H. Iwasaki, Acta Crystallogr. Sect. B 1973, 29, 2115–2124.
[42] C. S. Lai, E. R. T. Tiekink, Z. Kristallogr. New Crystal Struc-
tures 2002, 217, 593–597.
[43] F. Jian, Z. Wang, Z. Bai, X. You, H.-K. Fun, K. Chinnakali,
I. A. Razak, Polyhedron 1999, 18, 3401–3406.
[44] S. C. Ngo, K. K. Banger, M. J. DelaRosa, P. J. Toscano, J. T.
Welch, Polyhedron 2003, 22, 1575–1583.
[45] H.-B. Bürgi, E. Blanc, D. Schwarzenbach, S. Liu, Y. Lu, M. M.
Kappes, J. A. Ibers, Angew. Chem. Int. Ed. Engl. 1992, 31, 640–
643.
[46] A. Decken, R. A. Gossage, M. Y. Chan, C. S. Lai, E. R. T. Tie-
kink, Appl. Organomet. Chem. 2004, 18, 101–102.
[47] R. Hesse, Ark. Kemi 1963, 20, 481–484.
[48] D. D. Heinrich, J.-C. Wang, J. P. Fackler Junior, Acta Crys-
tallogr. Sect. C 1990, 46, 1444–1447.
[64] Y. A. Ossipyan, Y. I. Golovin, D. V. Lopatin, R. B. Morgunov,
R. K. Nikolaev, S. Z. Shmurak, Phys. Stat. Sol. B 2001, 223,
R14–R15.
[65] A. L. Buchachenko, E. L. Frankevich, Chemical Generation
and Reception of Radio- and Microwaves, Wiley, New York,
1994, p. 180.
[66] SMART and SAINT, Area detector control and integration
software, Ver. 6.01. Bruker Analytical X-ray Systems, Madison,
Wisconsin, U. S.A, 1999.
[67] G. W. Sheldrick, SHELXTL, An Integrated System for Solv-
ing, Refining and Displaying Crystal Structures from Diffrac-
tion Data, Version 5.10, Bruker Analytical Systems, Madison,
1997.
Received: December 12, 2005
Published Online: March 15, 2006
Eur. J. Inorg. Chem. 2006, 1881–1895
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
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