The first mononuclear η2-C60 complex of osmium: Synthesis and X-ray crystal structure of [(η2-C60)Os(CO)(tBuNC)(PPh3) 2]

Article abstract of DOI:10.1002/ejic.200300078

The interaction of C₆₀ fullerene with the cis-dihydride osmium complex [OsH₂(CO)(PPh₃)₃] (I) in the presence of tBuNC gives a novel metal complex [(η²-C₆₀)Os(CO)- (tBuNC)(PPh₃)₂] (II) as the first mononuclear osmium complex with an η²-coordinated fullerene ligand. Complex II was isolated and characterized by elemental analysis, UV, IR, ¹H and ³¹P NMR spectroscopy. An X-ray diffraction study of II as its dichlorobenzene solvate revealed a distorted trigonal bipyramidal coordination of the Os atom, with a 6/6 bond of C₆₀ and two PPh₃ ligands in the equatorial plane and CO and tBuNC as axial ligands. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.

Full text of DOI:10.1002/ejic.200300078

SHORT COMMUNICATION
The First Mononuclear η2-C60 Complex of Osmium: Synthesis and X-ray
Crystal Structure of [(η2-C60)Os(CO)(tBuNC)(PPh3)2]
Alexander V. Usatov,*[a] Ekaterina V. Martynova,[a] Ivan S. Neretin,[a] Yuri L. Slovokhotov,[a]
Alexander S. Peregudov,[a] and Yurii N. Novikov[a]
Keywords: Fullerenes / Olefins / Osmium / Pi interactions
The interaction of C60 fullerene with the cis-dihydride
osmium complex [OsH2(CO)(PPh3)3] (I) in the presence of
tBuNC gives
as its dichlorobenzene solvate revealed a distorted trigonal
bipyramidal coordination of the Os atom, with a 6/6 bond of
C60 and two PPh3 ligands in the equatorial plane and CO and
tBuNC as axial ligands.
a
novel metal complex [(η2-C60)Os(CO)-
(tBuNC)(PPh3)2] (II) as the first mononuclear osmium com-
plex with an η2-coordinated fullerene ligand. Complex II was
1
isolated and characterized by elemental analysis, UV, IR, H ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
and 31P NMR spectroscopy. An X-ray diffraction study of II
Germany, 2003)
A large number of mononuclear complexes of fullerenes generated in situ from the corresponding metal cis-dihy-
with transition metals, with general formula (η2-Cn)ML dride complex and tert-butyl isocyanide. The tBuNC li-
(where L stands for any ligand environment of M metal), gand, having both π-acceptor and σ-donor properties, plays
with an olefin-like π-coordinated fullerene moiety have been a dual role in the synthesis: as a strong π-acceptor it pro-
obtained and structurally characterized for most metals of motes the reductive elimination of a dihydrogen molecule
the platinum family, including Ru,[1] Rh,[2Ϫ4] Ir,[5,6] Pd,[7,8] from the initial dihydride complex after ligand substitution,
and Pt.[9Ϫ11] Based on their structures and spectroscopic to give a low-valent intermediate, whereas as a σ-donor it
properties, (η2-Cn) fullerene ligands in such mononuclear enhances the electron density at the metal center facilitating
complexes are believed to be analogues of acceptor η2- the effective coordination of the bulky and electron-de-
olefins with electron-withdrawing substituents (e.g. tetra- ficient fullerene ligand.
fluoroethylene or tetracyanoethylene).[12,13] However, no
As a starting cis-dihydride complex, the well-known and
mononuclear η2-derivatives of fullerenes with osmium have readily available [OsH2(CO)(PPh3)3][19] (I), which does not
been reported to date, notwithstanding the fact that an react directly with C60, was chosen. However, when C60 and
exopolyhedrally coordinated osmate complex of C60, I are refluxed together in toluene with tBuNC, a substi-
(σ,σ-C60)O2OsO2(4-tert-butylpyridine)2, was the first fuller- tution of triphenylphosphane ligand for isocyanide occurs,
ene derivative studied by single-crystal X-ray diffraction.[14] accompanied by elimination of dihydrogen, giving rise to a
Meanwhile, a number of osmium tri-[15Ϫ17] and penta- new [(η2-C60)Os(CO)(tBuNC)(PPh3)2] complex (II)
nuclear clusters,[17,18] with the C60 moiety connected (Scheme 1).
to a cluster core in an η2- [in Os3(CO)11(η2-C60)[15]],
The product II, obtained in analytically pure form by
[17]
η1:η2:η1-,[16] η2:η2-
or η2:η2:η2-mode,[15,17,18] have been chromatography, was characterized by microanalysis and
obtained and structurally characterised by X-ray methods.
spectroscopy data (UV/Vis, IR, 1H and 31P NMR). The
In this paper we report the synthesis of the first mono- UV/Vis pattern of II is rather typical for transition metal
nuclear π-complex of osmium with buckminsterfullerene as η2-C60 complexes.[3,6,20] The presence of a strong ν(CO)
an η2-ligand and its structural characterization by single- band at 1953 cmϪ1 and a strong single ν(NC) band at 2153
crystal X-ray diffraction. To reach this goal, we have used cmϪ1 in the IR spectrum of II reveals both isocyanide and
the method recently developed by us for a synthesis of the carbonyl ligands to be present in the molecule, pointing to
mixed-ligand η2-C60 and σ-carboranyl derivative of iridium a specific substitution of the triphenylphosphane ligand.
1
[(η2-C60)Ir(o-HCB10H9CCH2PPh2-B,P)(tBuNC)2].[6] This According to the H NMR spectroscopic data, complex II
approach is based on the interaction of the C60 molecule contains two PPh3 and one tBuNC ligand, whereas the
with a coordinatively unsaturated reactive intermediate, presence of only one singlet resonance at δ ϭ 7.9 ppm in
the 31P{1H} NMR corresponds to the existence of only one
[a]
A. N. Nesmeyanov Institute of Organoelement Compounds,
isomer, with two equivalent PPh3 ligands, in solution. The
Russian Academy of Sciences,
latter may be considered as evidence of metal-fullerene co-
Vavilov St. 28, Moscow 119991, Russia
Fax: (internat.) ϩ7-095/135-5085
ordination by the 1Ϫ2 bond (see discussion in ref.[20]).
Eur. J. Inorg. Chem. 2003, 2041Ϫ2044
DOI: 10.1002/ejic.200300078
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2041

A. V. Usatov et al.
SHORT COMMUNICATION
Scheme 1
The analytical data for II (C, H P, Os) correspond un- 23.2 and 24.0° at these atoms of II, 7.4Ϫ8.6° at their neigh-
equivocally to a monoadduct such as [(C60)Os(CO)(t- bors and 10.5Ϫ13.5° at all other C atoms].
BuNC)(PPh3)2]. However, the available spectroscopic data
do not allow us to distinguish between the possible equa-
torial (with carbonyl and tBuNC as axial ligands) and
trans-axial positions of the two equivalent PPh3 ligands.
Notwithstanding a close resemblance of the spectroscopic
data for II with those of the related complex
[Os(C2F4)(CO){(p-Tolyl)NC}(PPh3)2] [ν(CO) ϭ 1968 cmϪ1
,
ν(NC) ϭ 2160 cmϪ1; δP ϭ 3.5 ppm],[21] with two equivalent
equatorial PPh3 ligands and strong preference of equatorial
location of bulky PPh3 and fullerene ligands due to the
steric repulsion, no decisive evidence was obtained in favor
of one of the two possible isomers from the spectroscopic
data.
To determine the molecular geometry of II unequivocally
and to analyze its structural features, we grew a single crys-
tal of II from o-dichlorobenzene solution and performed an
X-ray diffraction study.
Figure 1. Molecule II with atomic numbering in the coordination
environment of the Os atom (hydrogen atoms not shown); bond
˚
lengths (A): OsϪP(1) 2.347(2), OsϪP(2) 2.351(1) OsϪC(37)
1.898(2), OsϪC(38) 2.011(2), OsϪC(101) 2.193(5), OsϪC(102)
The molecular structure of II·2.5C6H4Cl2 with selected
geometric parameters (bond lengths and bond angles) is
shown in Figure 1. The molecule [(η2-C60)Os(CO)(t-
BuNC)(PPh3)2] has an ordered C60 moiety with a normal
olefin-type π-coordination to the osmium atom. A trigonal
bipyramidal ligand environment of Os in II is completed by
two equatorial PPh3 ligands, with one isocyanide and one
CO ligand in the axial positions. Most of the bond lengths
and angles (see Figure 1) have their normal values. How-
ever, the bond angles P(1)ϪOsϪP(2) [109.58(5)°],
P(1)ϪOsϪC60 [120.3(1)°] and P(2)ϪOsϪC60 [130.1(1)°] in
the equatorial plane of the trigonal bipyramid (where C60
denotes a center of the coordinated 6/6 bond) display a sub-
stantial asymmetry due to intramolecular CϪH···C steric
repulsion between one Ph substituent at P(2) and C60
2.193(5),
C(37)ϪO(1)
1.146(4),
C(38)ϪN(1)
1.169(6),
C(101)ϪC(102) 1.479(7); bond angles (°): P(1)ϪOsϪP(2) 109.58(5),
P(1)ϪOsϪC(37)
P(1)ϪOsϪC(38)
88.52(8),
96.13(8),
P(2)ϪOsϪC(37)
P(2)ϪOsϪC(38)
92.41(7),
84.26(7),
C(37)ϪOsϪC(38) 175.0(1), OsϪC(37)ϪO 178.0(2), OsϪC(38)ϪN
173.9(2)
It is interesting to note that only two mononuclear phos-
phane π-complexes of osmium with η2-coordinated olefins
having electron acceptor substituents, viz. [(Ph3P)2Os-
(CO)2(η2-C4H2O3)][21] (with maleic anhydride) and
[(iPr3P)2OsH(OH)(CO)(η2-CH2ϭCHCOOMe)][23]
(with
methylmetacrylate) are found in the last (2002) version of
the Cambridge Structural Database (CSD). Mononuclear
π-complexes of Ru with electron-accepting olefins, which
have been studied in more detail, include derivatives of
tetrafluoroethylene [(Ph3P)2Ru(CO)2(η2-C2F4)],[21] maleic
anhydride [(Ph3P)2Ru(CO){(p-Tolyl)NC}(η2-C4H2O3)],[24]
and buckminsterfullerene [(Ph3P)2RuCl(NO)(η2-C60)].[1]
The main geometric molecular parameters of these com-
plexes are compared with the corresponding parameters of
II in Table 1.
˚
(shortest H···C distances at 2.64Ϫ2.87 A are slightly less
than the sum of their van der Waals radii). Metal-fullerene
bonding leads to elongation of η2-coordinated 6/6 bonds to
˚
˚
1.498(7) A from the normal value of 1.39 A in pristine C60
and a more pyramidal environment of the C atoms [the
spherical excess (spherical excess is 360° Ϫ Σ(all CCC bond
angles) of the carbon environment, which is a good quanti-
˚
The OsϪC(C60) bond lengths [2.193(5) A] in II are typi-
tative measure of pyramidalization,[22] is 12° in pristine C60, cal for mononuclear complexes with π-coordinated acceptor
2042
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2003, 2041Ϫ2044

The First Mononuclear η2-C60 Complex of Osmium
Table 1. Geometric parameters of the pentacoordinate metal environment in II and several closely related complexes
SHORT COMMUNICATION
Complex
MϪP
(A)
MϪCO
(A)
MϪC(π)
(A)
PϪMϪP
(deg.)
C2(π)ϪM-L
(deg.)
Ref.
˚
˚
˚
[a]
[(Ph3P)2Os(CO)(tBuNC)(η2-C60)] (II)
[(Ph3P)2Os(CO)2(η2-C4H2O3)][b]
2.35
2.43
2.40
2.45
2.37
2.43
1.90
1.91
1.84
Ϫ
2.19
2.18
2.19
2.22
2.19
2.09
109.6
99.3[c]
144.3[e]
113.2
107.0
101.4
120.3
130.3
86.1
[21]
[23]
[1]
117.4[c]
104.3
109.0
122.3
124.3
117.3
135.6
127.5
131.1
[(iPr3P)2OsH(OH)(CO)(η2-CH2ϭCHCO2Me)][d]
[(Ph3P)2RuCl(NO)(η2-C60)]
[24]
[21]
[(Ph3P)2Ru(CO)[(p-Tolyl)NC](η2-C4H2O3)][b]
[(Ph3P)2Ru(CO)2(η2-C2F4)]
1.85
1.92
[a]
[b]
[c]
Two PPh3 and two CO ligands in equatorial and axial positions, respectively. η2-Methyl methacrylate. Hydride H atom between
two equatorial PPh3 ligands. η2-Methyl methacrylate. Hydride H atom between two equatorial PPh3 ligands.
[d]
[e]
Experimental Section
olefins (see Table 1), and are almost identical to the
OsϪC(olefin) distances in [(Ph3P)2Os(CO)(η2-C2H4)2]
General: All manipulations were performed under oxygen-free ar-
[25]
˚
(2.15Ϫ2.19 A).
In
a
disordered structure of
gon in dry degassed solutions. IR spectra were obtained on a Spe-
cord M80 spectrometer. 1H NMR spectra (400.3 MHz) and
31P{1H} NMR spectra (160.02 MHz) were recorded on a Bruker
AMX-400 spectrometer and are quoted relative to residual signals
of the solvent (internal standard) and 85% H3PO4 (external stand-
ard), respectively. [OsH2(CO)(PPh3)3] was prepared by a standard
literature procedure.[19b]
[Os3(CO)11(η2-C60)], η2-coordination to one of three Os
atoms in a triangular cluster is accompanied by larger dis-
[15]
˚
tances (2.22Ϫ2.27 A)
that lie within the usual range
2
2
2
˚
(2.21Ϫ2.32 A) for a multicenter Os3-(η : η :η -C60) coordi-
nation.[15,17,18] A planar trigonal arrangement of two phos-
phanes and the center of the coordinated 6/6 bond of the
η2-C60 ligand in the equatorial plane around the Os atom
in II is similar to other mononuclear fullerene derivatives
like [(PPh3)2Pd(η2-C60)],[7] [(PPh3)2Pd(η2-C70)],[8] [(DIOP)2-
Pt(η2-C60)],[11] [(PPh3)2RuCl(NO)(η2-C60)],[1] [(PPh3)2RhH-
(CO)(η2-C60)],[2] and [L2IrCl(CO)(η2-Cn)] (where L is a
phosphane ligand).[13] Unlike the symmetric L2M-(6/6
bond) fragment in all these complexes, the PϪOsϪC60
angles in II differ by 10°. However, in the related pentacoor-
dinate complex [(PPh3)2Ru(CO)[(p-tolyl)NC](η2-malonic
anhydride)] with carbonyl and isocyanide axial ligands,[24]
which is the closest non-fullerene analogue of II, the
PϪRu(olefin) angles in the equatorial plane differ by 18.3°
(see Table 1). Even the large angle difference in mono-
nuclear [(Ph3P)2Os(CO)2(η2-C4H2O3)] is due to the axial
position of one PPh3 ligand,[21] whereas in [(iPr3P)2OsH-
(OH)(CO)(η2-CH2ϭCHCOOMe)] a hydride ligand is situ-
ated between two iPPr3 groups in the equatorial plane.[23]
Such asymmetry of the flexible metal coordination
probably refers to an interplay of interligand repulsion and
molecular packing forces in the crystal.
Synthesis of [(η2-C60)Os(CO)(tBuNC)(PPh3)2] (II): [OsH2-
(CO)(PPh3)3] (I) (0.0699 g, 0.069 mmol) and tBuNC (17.2 µL,
0.153 mmol) were added to a solution of C60 (0.050 g, 0.069 mmol)
in toluene (50 mL), with stirring, and the reaction mixture was re-
fluxed for 24 h. After cooling the reaction mixture to room tem-
perature, a small quantity (0.013 g) of insoluble precipitate (not
further unidentified) was filtered off, and the solution was concen-
trated to 5 mL and then diluted with pentane. The precipitate was
filtered, washed with pentane, dissolved in 1 mL of CHCl3 and
chromatographed on a short column packed with alumina, eluting
with a CHCl3/hexane mixture (1:1). A green fraction was collected,
solvents were removed under reduced pressure and the residue was
washed with pentane, and dried in vacuo at 60 °C to give 41 mg
(38%) of II. C102H39NOOsP2 (1546.6): calcd. C 79.21, H 2.54, Os
12.30, P 4.00; found C 78.47, H 2.64, Os 12.77, P 4.35. UV/Vis
(THF): λ ϭ 259, 333, 394 (sh), 444, 671 nm. IR (KBr pellet): ν˜ ϭ
1
2153 cmϪ1 (NC), 1953 (CO). H NMR (CDCl3): δ ϭ 0.86 (s, 9 H,
tBu), 7.32 (m, 18 H, Ph), 7.58 (m, 12 H, Ph) ppm. 31P{1H} NMR
(CDCl3): δ ϭ 7.9 ppm.
X-ray Structure Determination of II: Dark green crystals of II·2.5(o-
C6H4Cl2) were grown by slow diffusion of heptane into an o-di-
chlorobenzene solution of complex II at room temperature. The
Thus, we have shown that the interaction of fullerene
with cis-dihydride transition metal complexes in the pres-
ence of isocyanide gives a rather convenient and general
synthetic route to (η2-C60) metal complexes. It allowed us
to obtain the first mononuclear osmium fullerene complex
[(η2-C60)Os(CO)(tBuNC)(PPh3)2] whose crystal and
molecular structure was completely characterized by single-
crystal X-ray diffraction.
¯
crystals are triclinic, space group P1, a ϭ 13.254(3), b ϭ 16.753(4),
˚
c ϭ 18.642(4) A, α ϭ 87.575(5)°, β ϭ 74.626(5)°, γ ϭ 73.672(5)°,
3
V ϭ 3828(1) A , Z ϭ 2, dcalcd. ϭ 1.661 g/cm3, and µ(Mo-Kα) ϭ
˚
19.52 mmϪ1. The intensities of 21936 unique reflections (Rint
ϭ
0.063) were measured at 110(2) K on a Bruker SMART 1000 CCD
diffractometer (graphite monochromated Mo-Kα radiation, λ ϭ
˚
0.71073 A, ω and scan technique with a 0.3° step in ω and 10 s
per frame exposure, θ Յ 30.15°). Reflection intensities were inte-
grated using the SAINT software[26] and corrected for absorption
Eur. J. Inorg. Chem. 2003, 2041Ϫ2044
www.eurjic.org
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2043

A. V. Usatov et al.
SHORT COMMUNICATION
semiempirically (SADABS program)[26] based on multiple measure-
ments of identical reflections and equivalents. The structure was
solved by direct methods and refined by full-matrix least-squares
against F2. Two molecules of o-dichlorobenzene were located in
general positions, and one more such molecule, disordered about
the inversion center, was found in the difference Fourier map. One
of the two o-dichlorobenzene molecule appeared to be disordered.
All disordered atoms in the crystal structure of II were refined with
isotropic thermal parameters. All H atoms were placed geometri-
cally and included in the refinement using a riding model. The re-
finement converged to wR2 ϭ 0.1074 and GOF ϭ 0.733 for all
independent reflections (R1 ϭ 0.0543 was calculated against F for
a total of 10492 observed reflections with I Ͼ 2σ(I)]; the number
of refined parameters was 1127. All calculations were performed
with SHELXTL-97.[27]
I. A. Guzey, Yu. T. Struchkov, Organometallics 1993, 12,
991Ϫ992.
M. M. Olmstead, L. Hao, A. L. Balch, J. Organomet. Chem.
1999, 578, 85Ϫ90.
P. J. Fagan, J. C. Calabrese, B. Malone, Science 1991, 252,
1160Ϫ1161.
M. Iyoda, Y. Ogawa, H. Matsuyama, H. Ueno, K. Kikuchi, I.
Ikemoto, Y. Achiba, Fullerene Sci. Technol. 1995, 3, 1Ϫ9.
V. V. Bashilov, P. V. Petrovsky, V. I. Sokolov, F. M. Dolgushin,
A. I. Yanovsky, Yu. T. Struchkov, Russ. Chem. Bull. 1996, 45,
1207Ϫ1213.
P. J. Fagan, J. C. Calabrese, B. Malone, Acc. Chem. Res. 1992,
25, 134Ϫ142, and references therein.
A. L. Balch, M. M. Olmstead, Chem. Rev. 1998, 98,
2123Ϫ2165, and references therein.
J. M. Hawkins, A. Meyer, T. A. Lewis, S. Loren, F. J. Hollander,
Science 1991, 252, 312Ϫ313.
J. T. Park, H. Song, J.-J. Cho, M.-K. Chung, J.-H. Lee, I.-H.
Suh, Organometallics 1998, 17, 227Ϫ236.
H. Song, K. Lee, C. H. Lee, J. T. Park, H. Y. Chang, M.-G.
Choi, Angew. Chem. Int. Ed. 2001, 40, 1500Ϫ1502; Angew.
Chem. 2001, 113, 1548Ϫ1550.
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
CCDC-202941 contains the supplementary crystallographic data
for this paper. These data can be obtained free of charge at
www.ccdc.cam.ac.uk/conts/retrieving.html [or from the Cambridge
Crystallographic Data Centre, 12, Union Road, Cambridge
CB2 1EZ, UK; Fax: (internat.) ϩ44-1223/336-033; E-mail:
deposit@ccdc.cam.ac.uk].
[17]
[18]
K. Lee, C. H. Lee, H. Song, J. T. Park, H. Y. Chang, M.-G.
Choi, Angew. Chem. Int. Ed. 2000, 39, 1801Ϫ1804; Angew.
Chem. 2000, 112, 1871Ϫ1874.
H. Song, K. Lee, J. T. Park, M.-G. Choi, Organometallics 1998,
Acknowledgments
17, 4477Ϫ4483.
[19] [19a]
This work was supported by the Russian Foundation for Basic Re-
search (Projects Nos. 00-03-32807, 02-03-33225 and 02-03-06419),
the Russian Federation State Research Program ‘‘Fullerenes and
atomic clusters’’ [Contr. No. 107-14 (00)-P], and by the Russian
Federation Ministry of Industry, Science, and Technology Sub-
Program ‘‘Fundamental Problems of Modern Chemistry’’ [Contr.
No. 402-19.6/22.3/23.1 (00)-P]. The authors are grateful to Prof.
Mikhail Yu. Antipin for access to the equipment of the Center for
X-ray Structural Studies, Institute of Organoelement Compounds.
N. Ahmad, S. D. Robinson, M. F Uttley, J. Chem. Soc.,
[19b]
Dalton Trans. 1972, 843Ϫ847.
N. Ahmad, J. J. Levison, S.
D. Robinson, M. F Uttley, Inorg. Synth. 1974, 15, 54Ϫ55.
A. V. Usatov, K. N. Kudin, E. V. Vorontsov, L. E. Vinogradova,
Yu. N. Novikov, J. Organomet. Chem. 1996, 522, 147Ϫ153.
A. K. Burrell, G. R. Clark, C. E. F. Rickard, W. R. Roper, D.
C. Ware, J. Organomet. Chem. 1990, 398, 133Ϫ158.
I. S. Neretin, K. A. Lyssenko, M. Yu. Antipin, Yu. L. Slovokh-
otov, O. V. Boltalina, P. A. Troshin, A. Yu. Lukonin, L. N.
Sidorov, R. Taylor, Angew. Chem. Int. Ed. 2000, 39,
3273Ϫ3276; Angew. Chem. 2000, 112, 18, 3283Ϫ3283.
A. J. Edwards, S. Elipe, M. A. Esteruelas, F. J. Lahoz, L. A.
Oro, C. Valero, Organometallics 1997, 16, 3828Ϫ3836.
C. E. F. Rickard, W. R. Roper, L. J. Wright, L. Young, J. Or-
ganomet. Chem. 1989, 364, 391.
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[1]
A. N. Chernega, M. L. H. Green, J. Haggitt, A. H. H. Ste-
phens, J. Chem. Soc., Dalton Trans. 1998, 755Ϫ767.
A. L. Balch, J. W. Lee, B. C. Noll, M. M. Olmstead, Inorg.
[2]
Chem. 1993, 32, 3577Ϫ3578.
[3]
G.-Y. Kiel, J. Takats, F.-W. Grevels, J. Am. Chem. Soc. 1987,
109, 2227Ϫ2229.
SMART and SAINTPLUS, Area detector control and inte-
gration software, Ver. 6.01. Bruker Analytical X-ray Systems,
Madison, Wisconsin, U. S. A, 1999.
Y. Ishii, H. Hoshi, Y. Hamada, M. Hidai, Chem. Lett. 1994,
801Ϫ804.
[4]
H. Song, K. Lee, J. T. Park, I.-H. Suh, J. Organomet. Chem.
1999, 584, 361Ϫ365.
[5]
A. L. Balch, V. J. Catalano, J. W. Lee, Inorg. Chem. 1991, 30,
[27]
3980Ϫ3981.
SHELXTL, An integrated system for solving, refining and dis-
playing crystal structures from diffraction data, Ver. 5.10.
Bruker Analytical X-ray Systems, Madison, Wisconsin, U. S.
A, 1997.
[6]
A. V. Usatov, E. V. Martynova, F. M. Dolgushin, A. S. Peregu-
dov, M. Yu. Antipin, Yu. N. Novikov, Eur. J. Inorg. Chem.
2002, 2565Ϫ2567.
V. V. Bashilov, P. V. Petrovskii, V. I. Sokolov, S. V. Lindeman,
[7]
Received February 11, 2003
2044
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2003, 2041Ϫ2044