Ruthenium vs. osmium complexes as catalysts for atom transfer radical addition reactions

Article abstract of DOI:10.1002/ejic.201000388

The catalytic activity of [C_p*OsBr₂(PPh ₃)] in conjunction with Mg has been evaluated for atom transfer radical addition (ATRA) and cyclization (ATRC) reactions. The Os complex enabled these reactions to be performed with

Full text of DOI:10.1002/ejic.201000388

FULL PAPER
DOI: 10.1002/ejic.201000388
Ruthenium vs. Osmium Complexes as Catalysts for Atom Transfer Radical
Addition Reactions
Mariano A. Fernández-Zúmel,[a] Gregor Kiefer,[a] Katrin Thommes,[a] Rosario Scopelliti,[a]
and Kay Severin*[a]
Keywords: ATRA / ATRC / Osmium / Radical reactions / Ruthenium
The catalytic activity of [Cp*OsBr2(PPh3)] in conjunction with
Mg has been evaluated for atom transfer radical addition
(ATRA) and cyclization (ATRC) reactions. The Os complex
enabled these reactions to be performed with similar effi-
ciency as that of the analogous Ru complex [Cp*RuCl2-
(PPh3)]. The olefin complex [Cp*OsBr(H2C=CHPh)(PPh3)]
was obtained by reduction of [Cp*OsBr2(PPh3)] with Mg in
the presence of an excess of styrene, whereas an analogous
Ru complex was not observed. Kinetic investigations suggest
that olefin complexes of Os can form under catalytic condi-
tions.
case of Os, whereas the analogous Ru complexes are signifi-
cantly less stable. The implication of this finding for the
mechanism of the reaction is discussed.
Introduction
Halogenated compounds can be coupled to olefins by
an atom transfer radical addition mechanism. Pioneering
studies in this area were performed by Kharasch and his
group in the 1940s,[1] and reactions of this type are com-
monly referred to as “Kharasch reactions”.[2] Modern,
transition-metal-catalyzed versions of this reaction have
found numerous applications in organic synthesis.[2,3] Cop-
per[4] and ruthenium complexes[5,6] typically show the best
catalytic performance for ATRA reactions. One of the most
active catalysts described so far is the half-sandwich com-
plex [Cp*RuCl2(PPh3)] (1), which is used in conjunction
with either AIBN or Mg.[6] This catalytic system enables
turnover numbers of 1000 or above to be obtained for a
number of substrates. Furthermore, it has been successfully
applied to atom transfer radical cyclization (ATRC) reac-
tions, which are particularly interesting from a synthetic
point of view.[6a]
The metal-catalyzed atom transfer radical polymeriza-
tion (ATRP) of olefins is mechanistically closely related to
ATRA reactions.[3b] For the former reaction, it was re-
ported that the OsII complex [Cp*OsBr(PiPr3)] is a more
active catalyst than its Ru analogue [Cp*RuCl(PiPr3)].[7]
This finding suggested that Os complexes could also be
beneficial for ATRA and ATRC reactions. Below we report
the results of a study in which we have compared the cata-
lytic activity of the complex [Cp*RuCl2(PPh3)] (1) with that
of its Os analogue [Cp*OsBr2(PPh3)] (2). Furthermore, we
demonstrate that olefin complexes are readily formed in the
Results and Discussion
First, we have evaluated the catalytic performance of the
complexes [Cp*RuCl2(PPh3)] (1) and [Cp*OsBr2(PPh3)] (2)
for different intermolecular ATRA reactions. Complex 2 is
not a perfect analogue of 1, because – apart from the
metal – the halide coligand has also been changed from
chloride to bromide. The synthetic chemistry of organome-
tallic Os–Br complexes is much more developed than the
chemistry of Os–Cl complexes (the reduction of OsO4 is
more facile with HBr than with HCl).
The halogenated compounds used in our study were
ethyl trichloroacetate, ethyl dichloroacetate, and chloro-
form, and the olefinic reaction partner was styrene. The re-
actions were performed with substrate concentrations of
[styrene] = [R–Cl] = 500 m in neat toluene with catalyst
concentrations of 0.1 and 0.02 mol-%. All reactions were
carried out in the presence of an excess of Mg powder. It
should be noted that these conditions are not necessarily
the optimum conditions for these reactions (faster conver-
sions can be achieved with higher substrate concentra-
tions),[6a] but the goal of this study was to evaluate the rela-
tive performance of the Ru and the Os catalyst. The results
of the reactions are summarized in Table 1.
For the addition of ethyl dichloroacetate to styrene at
room temp. we found that reactions with the Ru complex 1
were faster than with the Os complex 2: after 24 h, we ob-
served a full conversion of styrene in the case of complex
1, whereas a conversion of only 57% was recorded for reac-
tions with complex 2 (Table 1, Entries 1 and 2). At 60 °C,
[a] Institut des Sciences et Ingénierie Chimiques, École
Polytechnique Fédérale de Lausanne (EPFL)
1015 Lausanne, Suisse
Fax: +41-21-693-9305
E-mail: kay.severin@epfl.ch
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Catalysts for Atom Transfer Radical Addition Reactions
Table 1. ATRA reactions of chlorinated compounds to styrene cat- of yield. On the other hand, the diastereoselectivity was
alyzed by complex 1 or 2 in the presence of Mg.[a]
higher for the Os-catalyzed reactions, in particular for the
substrate 1-(2,2,2-trichloroethoxy)-3-phenylprop-2-ene (En-
try 2). It should be noted, however, that the stereoselectivity
was found to change during the course of the reaction.
When ATRC reactions with 1-(2,2,2-trichloroethoxy)-3-
phenylprop-2-ene were examined after 40 min, both the Ru-
and the Os-catalyzed reactions showed a diastereoselectivity
of 19:1 (the yields at that point were 61% and 20%, respec-
tively). These results suggest that epimerization processes
are occurring, which are more pronounced for reactions
with the “faster” Ru catalyst.
Entry Cat.
RCl
Temp. [°C] [RCl]/[Cat]
Yield (Conv.)
[%]
1
2
3
4
5
6
7
8
9
1
2
1
2
1
2
1
2
1
2
1
2
CCl2HCO2Et
CCl2HCO2Et
CCl2HCO2Et
CCl2HCO2Et
CCl2HCO2Et
CCl2HCO2Et
CCl3CO2Et
CCl3CO2Et
CCl3CO2Et
CCl3CO2Et
CHCl3
r.t.
r.t.
60
60
60
60
60
60
60
60
60
60
1000:1
1000:1
1000:1
1000:1
5000:1
5000:1
1000:1
1000:1
5000:1
5000:1
1000:1
1000:1
84 (Ͼ99)
42 (57)
84 (Ͼ99)
84 (Ͼ99)
14 (31)
16 (39)
55 (83)
24 (45)
17 (31)
3 (14)
Table 2. ATRC reactions catalyzed by complex 1 or 2 in the pres-
ence of Mg.[a]
10
11
12
28 (47)
31 (47)
CHCl3
[a] Reaction conditions: [RCl] = 500 m; [styrene] = 500 m; [Ru/
Os] = 0.50 or 0.10 m (0.1 or 0.02 mol-%), [Mg] = 100 mg
(4.1 mmol), toluene, reaction time 24 h. The data represent
averaged values of two independent experiments. Yields and styrene
conversions were determined by GC using mesitylene as the in-
ternal standard.
however, the differences in reactivity were much less pro-
nounced, and comparable yields and conversions were ob-
tained for reactions with 0.1 and 0.02 mol-% of catalyst
(Table 1, Entries 3–6). Apparently, the Os complex 2 bene-
fits more from the enhanced reaction temperature. A pos-
sible explanation is that the reduction of the OsIII precursor
2 to a catalytically active OsII species by Mg is relatively
slow at room temp. This assumption is substantiated by the
following observation: when a toluene solution of the RuIII
complex 1 is added to a flask containing Mg, a rapid color
change from orange to yellow is observed at room temp.
within minutes. In the case of the OsIII complex 2, however,
a change in color proceeds slowly within the first hour.
[a] Reaction conditions: [substrate] = 100 m; [Ru/Os] = 1.0 m
(1.0 mol-%), [Mg] = 100 mg (4.1 mmol), [D8]toluene, 60 °C, reac-
tion time: 24 h. Yields and conversions were determined by NMR
spectroscopy using mesitylene as the internal standard. [b] 2.5 mol-
% of catalyst was used. [c] Diastereoselectivity.
For ATRA reactions with the catalyst precursor
For the reaction of ethyl trichloroacetate with styrene, we [Cp*RuCl2(PPh3)] (1) it is assumed that the reaction starts
found that the Ru complex 1 gave superior results, even at by Mg-induced reduction to give an RuII complex that can
60 °C (Table 1, Entries 7–10). However, the differences in reversibly abstract a halogen atom from the substrate.[8]
A
reactivity were not very pronounced. Comparable yields likely candidate for the active RuII catalyst is the 16e– com-
and conversions were observed for reactions with chloro- plex [Cp*RuCl(PPh3)], but attempts to prepare this com-
form as the substrate (Table 1, Entries 11 and 12). For all plex on a preparative scale have failed.[9] However, it was
reactions investigated, the yields were lower than the con- possible to stabilize a structurally related complex by using
versions. This is likely to be a result of the formation of a sterically very demanding cyclopentadienyl ligand.[10] In
oligomers, a common problem in ATRA reactions.[4,5]
the case of Os, the synthesis and the structure of the 16e–
Next, we tested the performance of the catalysts 1 and 2 complex [Cp*OsBr(PiPr3)] has been reported,[11] but, to the
in atom transfer radical cyclization (ATRC) reactions. We best of our knowledge, an analogous PPh3 complex is not
used two trichloroethyl ethers and three dichloroacetamides known. We wanted to explore the Mg-induced reduction of
as representative substrates. The cyclizations were per- complex 2 in more detail. Thus, a [D8]toluene suspension
formed at 60 °C with 1.0 mol-% of the complexes 1 or 2 in of 2 (0.025 mmol in 1 mL of solvent) was mixed with an
the presence of Mg. The results are summarized in Table 2. excess of Mg. After 24 h, the Mg was filtered off, and the
In most cases the Ru complex 1 gave better results in terms solution was investigated by NMR spectroscopy. The major
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diamagnetic species in solution (36% yield, as determined found for the OsII complex 3 [2.5934(4) Å]. A similar short-
with the internal standard mesitylene) was found to be the ening has been observed for the analogous Ru complexes
known complex [Cp*OsBr(PPh3)2] (3) (Scheme 1).[12]
[Cp*RuCl2(PPh3)] [Ru–Cl 2.4042(5) and 2.3775(5) Å][6a]
and [Cp*RuCl(PPh3)2] [Ru–Cl 2.4583(6) Å].[14]
We have also investigated the reduction of the complexes
1 and 2 with Mg in the presence of an excess of styrene
(Scheme 2). This experiment was performed to evaluate
the possibility that the hypothetical intermediates
[Cp*MX(PPh3)] are stabilized by coordination to the ole-
finic substrate. As before, the reactions were performed in
deuterated toluene to allow in situ NMR analyses. For reac-
Scheme 1. Reduction of complex 2 by Mg.
The reduction of complex 2 with Mg apparently induced tions with the Os complex 2, we observed the formation of
a ligand transfer of PPh3. We have not tried to optimize this a new complex 4 with a 31P NMR signal at δ = 7.4 ppm.
1
synthetic procedure since complex 3 is more conveniently In the H NMR spectrum, this complex showed three well-
obtained by reaction of [Cp*OsBr2]2 with PPh3.[12] How- defined signals at δ = 5.71 (dd), 2.91 (ddd), and 2.47 (ddd)
ever, we have performed a single-crystal X-ray analysis of 3 ppm, which suggests the presence of coordinated styrene
(Figure 1). For comparison, we have also examined the so- (the signals of “free” styrene can be observed at δ = 6.82,
lid-state structure of the precursor 2 (Figure 2).
5.86, and 5.35 ppm). The description of 4 as an olefin com-
plex with the formula [Cp*OsBr(H2C=CHPh)(PPh3)] was
also supported by the 13C NMR spectroscopic data. For
reactions with the Ru complex 1 we did not find evidence
for the formation of a diamagnetic styrene complex (the 1H
NMR spectrum showed no signals between δ = 2 and
3 ppm). It is interesting to note that olefin complexes of the
formula [Cp*RuCl(H2C=CHR)(PPh3)] (R = CN, COCH3)
have been prepared by reaction of [Cp*RuCl(PPh3)2] with
the respective olefin in thf.[15] We have attempted a similar
reaction with styrene: complex [Cp*RuCl(PPh3)2]
(0.020 m) was mixed with styrene (0.050 m) in [D8]thf,
1
and an H NMR spectrum was recorded after 4 h. As be-
Figure 1. Molecular structure of complex 3 with ellipsoids at the
50% probability level. Only one of the two independent molecules
in the unit cell is shown. Selected bond lengths [Å] and angles [°]:
Os1–Br1 2.5934(4), Os1–P1 2.3370(9), Os1–P2 2.3313(9); P2–Os1–
P1 96.51(3), P2–Os1–Br1 88.61(2), P1–Os1–Br1 93.98(2).
fore, we did not observe signals corresponding to an olefin
complex. These results suggest that the hypothetical styrene
complex [Cp*RuCl(H2C=CHPh)(PPh3)] is significantly less
stable than complexes with electron-deficient olefins such
as acrylonitrile or 3-buten-2-one, a finding that is in line
with what has been observed for other late-transition-metal
complexes.[16]
Scheme 2. Reduction of the complexes 1 and 2 by Mg in the pres-
Figure 2. Molecular structure of complex 2 with ellipsoids at the
50% probability level. Selected bond lengths [Å] and angles [°]:
Os1–Br1 2.5110(9), Os1–Br2 2.4955(8), Os1–P1 2.3379(1); P1–Os1–
Br1 88.49(5), P1–Os1–Br2 88.50(5), Br2–Os1–Br1 97.81(3).
ence of an excess of styrene.
The facile formation of the styrene complex
[Cp*OsBr(H2C=CHPh)(PPh3)] (4) has potential implica-
Both complexes show the expected three-legged piano- tions for the mechanism of Os-catalyzed ATRA reactions
stool geometry. The Os–Br and Os–P bond lengths ob- since olefin complexes are possible intermediates, which
served for 3 (Figure 1) are very similar to those found for could inhibit the reaction.[17] To investigate this issue in
the analogous complex [CpOsBr(PPh3)2] (Cp = η5-cyclo- more detail, we have performed a kinetic study of the Os-
pentadienyl).[13] The Os–Br bond lengths [2.5110(9) and catalyzed ATRA reaction of ethyl trichloroacetate with sty-
2.4955(8) Å] of the OsIII complex 2 are shorter than that rene. The reactions were performed with a fixed concentra-
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Catalysts for Atom Transfer Radical Addition Reactions
tion of [Cl3CCO2Et] = 100 m and [2] = 0.50 m in the
presence of Mg powder. The styrene concentrations were
varied from 12.5 m to 3.2 , and the initial rate of the
reaction was calculated from the yields obtained at nine dif-
ferent times within the first 25 min. For comparison, we
have performed reactions with the Ru complex 1 under
otherwise identical conditions. The results are summarized
in Figure 3.
Conclusions
We have studied the catalytic activity of the Os complex
[Cp*OsBr2(PPh3)] (2) in conjunction with Mg for intra- and
intermolecular atom transfer radical reactions. It was found
that the complex is a potent catalyst, which enables the
ATRA and ATRC reactions to be performed in an efficient
manner. However, under the conditions studied, its activity
was either similar or lower than that of [Cp*RuCl2(PPh3)]
(1). It is thus not justified to use a more expensive and toxic
Os complex for these types of reactions. The isolation of
[Cp*OsBr(H2C=CHPh)(PPh3)] (4) shows that olefin com-
plexes are more likely to form in reactions with Cp*Os cata-
lysts, and this should be considered for future studies with
Os-catalyzed polymerization reactions.[7,20]
Experimental Section
General: The complexes [Cp*RuCl2(PPh3)] (1),[21] [Cp*RuCl-
(PPh3)2],[22] and [Cp*OsBr2(PPh3)] (2),[23] were prepared according
to literature procedures. The substrates 1-(2,2,2-trichloroethoxy)-2-
phenylprop-2-ene,[5a]
1-(2,2,2-trichloroethoxy)-3-phenylprop-2-
ene,[24] N-allyl-2,2-dichloro-N-phenylacetamide,[25] N-allyl-2,2-
dichloro-N-(4-tolylsulfonyl)acetamide,[26] and N,N-diallyl-2,2-
dichloroacetamide[26] for the ATRC reactions were also prepared
according to published procedures. Mg powder (Ͼ99%) was pur-
chased from Fluka and was agitated by means of a stirring bar
under dry dinitrogen for 10 d before use. All ATRA, ATRC, and
synthesis reactions were performed in a glove box under dinitrogen.
The solvents were collected under dinitrogen from an Innovative
Technologies SPS-400-5 solvent system. The commercially available
substrates were distilled from appropriate drying agents and stored
under dinitrogen. GC measurements were made with a Varian
Chrompack CP3-380 apparatus (Chrompack CP-SIL8CB column;
30 m; 250 µm) coupled to an FID detector. The NMR spectra (1H,
13C, 31P) were recorded at room temp. with a Bruker AVANCE
DPX 400 spectrometer. Chemical shifts are relative to solvent sig-
nals as internal references; δ(31P) are relative to external H3PO4
(85% in D2O). Microanalyses (C, H, N) were performed with an
EA 1110 CHN Carlo Erba instrument.
Figure 3. Observed initial reaction rates vs. initial styrene concen-
trations for the ATRA of ethyl trichloroacetate to styrene catalyzed
by the RuIII complex 1 (dots) or by the OsIII complex 2 (triangles)
in the presence of Mg. Reaction conditions: [ethyl trichloroacetate]
= 100 m; [Ru/Os] = 0.50 m, [Mg] = 100 mg, toluene, 60 °C.
Yields were determined by GC using mesitylene as the internal
standard.
For reactions with the Ru catalyst 1 one observes a ne-
arly linear correlation between the initial reaction rate and
the styrene concentration for [styrene] Յ 200 m. This re-
sult is in line with what we observed previously for kinetic
studies carried out at 35 °C.[8] At higher styrene concentra-
tions, however, the reaction rates level off with saturation
occurring at [styrene] ≈ 2 . Such a saturation is expected
because the high styrene/Cl3CCO2Et ratio favors oligomeric
side products.[18] Reactions with the Os complex 2 were
slower than those with the Ru complex 1. Importantly, the
reaction rates started to level off at much lower styrene con-
centrations, and concentrations of above 1  led to a de-
crease in the rate.
In addition, we have investigated the catalytic activity of
the isolated styrene complex 4, using the addition of
ethyl dichloroacetate to styrene ([styrene] = 500 m,
[Cl2HCCO2Et] = 500 m, [4] = 0.50 m) as a test
reaction.[19] The initial rate of the reaction was found
to be 1.3(Ϯ0.2)ϫ10–5 s–1, which is lower than that ob-
General Procedure for the ATRA Reactions: An aliquot of a stock
solution of complex 1 or 2 in toluene (400 µL of a 1.25 m stock
solution) was added to a 1.5 mL vial containing Mg powder
(100 mg). The total volume was increased to 800 µL with toluene,
and the resulting mixture was stirred at room temp. or 60 °C for
10 min. The reaction was then initiated by addition of 200 µL of a
freshly prepared stock solution containing styrene, the chlorinated
compound, and mesitylene as an internal standard. The solution
was stirred at room temp. or 60 °C, and samples (25 µL) were re-
moved at given times from the reaction mixtures, diluted with non-
deoxygenated acetone (500 µL), and analyzed by GC chromatog-
raphy.
served for reactions with the catalyst precursor
2
[2.4(Ϯ0.3)ϫ10–5 s–1].
General Procedure for the ATRC Reactions: An aliquot of a stock
solution of complex 1 or 2 in [D8]toluene (800 µL of a 1.25 m
stock solution) was added to a 1.5 mL vial that contained Mg pow-
der (100 mg). The resulting mixture was stirred at 60 °C for 10 min.
The reaction was then initiated by addition of 200 µL of a freshly
prepared stock solution containing the substrate and mesitylene as
an internal standard in [D8]toluene. For N-allyl-2,2-dichloro-N-(4-
tolylsulfonyl)acetamide, a 1.5 mL vial was charged with 2.5 µmol
of the solid catalysts 1 (or 2), 100 mg of Mg, and 800 µL of [D8]-
The results suggest that Os-catalyzed ATRA reactions of
halogenated compounds with styrene can be inhibited by
the formation of olefin complexes, in particular when the
reactions are performed with high concentrations of styr-
ene. One should point out, however, that we have only indi-
rect evidence for the relevance of styrene complexes under
catalytic conditions, and alternative explanations for the
observed data cannot be ruled out.
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toluene, and the mixture stirred at 60 °C for 10 min, before 200 µL
of a freshly prepared stock solution containing the substrate and
mesitylene as an internal standard in [D8]toluene was added. After
fractometer, whereas in the case of 3 a Bruker APEX II CCD was
employed, both having kappa geometry and using graphite-mono-
chromatized Mo-Kα radiation (λ = 0.71073 Å) at low temperature.
A summary of the crystallographic data, the data-collection param-
eters, and the refinement parameters are given in Table 3. Data
reduction was carried out with CrysAlis PRO[27] (2) and Ev-
alCCD[28] (3) and then corrected for absorption.[29] Structure solu-
tion and refinement were performed with the SHELXTL software
package.[30] The structures were refined by using the full-matrix
least-squares routines on F2. All non-hydrogen atoms were refined
with anisotropic displacement parameters. Hydrogen atoms were
included in the models in calculated positions by using the riding
model. CCDC-772348 (2) and -772349 (3) contain the supplemen-
tary crystallographic data for this paper. These data can be ob-
tained free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
1
24 h, the reaction mixture was analyzed by H NMR spectroscopy.
Reduction of Complexes 1 and 2 with or without Styrene: Complex
1 or 2 (5.0 µmol) and Mg powder (100 mg) were suspended in [D8]-
toluene (1.0 mL). If styrene was used, 200 equiv. (1 mmol,
114.6 µL) of it were added. The resulting reaction mixtures were
stirred at room temp. for 2 h, and the liquid phase was analyzed
1
by H NMR and 31P NMR spectroscopy.
Synthesis of Complex 4: Styrene (800 µL, 6.99 mmol) was added to
a suspension of complex 2 (33 mg, 44 µmol) and Mg (300 mg) in
toluene (15 mL). The mixture was stirred at 35 °C for 15 h and
then filtered through a glass frit. Solvents and excess styrene were
removed under vacuum to give complex 4 as a yellow solid. Yield:
27 mg (ca. 75%). 1H NMR (400 MHz, C6D6): δ = 1.23 (d, J =
1.4 Hz, 15 H, C5Me5), 2.47 (ddd, J = 15.7, J = 7.7, J = 2.6 Hz, 1
H, CH=CH2), 2.91 (ddd, J = 10.2, J = 2.8, J = 2.6 Hz, 1 H,
CH=CH2), 5.71 (dd, J = 10.2, J = 7.7 Hz, 1 H, CH=CH2), 6.98–
8.18 (m, 20 H, aromatic) ppm. 31P{1H} NMR (162 MHz, C6D6):
δ = 7.4 ppm. 13C{1H} NMR (101 MHz, C6D6): δ = 8.98 (s, C5Me5),
21.0 (d, J = 4.4 Hz, CH=CH2), 41.8 (d, J = 2.9 Hz, CH=CH2),
92.1 (d, J = 2.9 Hz, C5Me5), 124.8–136.9 (m), 145.9 (s) ppm.
Attempts to characterize complex 4 by elemental analysis were un-
fortunately not successful. We assume that the styrene ligand is
partially removed during the drying procedure.
Acknowledgments
This work was supported by the Swiss National Science Founda-
tion and by the Ecole Polytechnique Fédérale de Lausanne
(EPFL). We thank Dr. E. Solari for help with the crystallographic
measurements.
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Table 3. Crystallographic data for the complexes 2 and 3.
Complex 2
Complex 3
Empirical formula
Mr [gmol–1]
Crystal size [mm]
Crystal system
Space Group
a [Å]
b [Å]
c [Å]
α [°]
C28H30Br2OsP
747.51
0.32ϫ0.28ϫ0.17
monoclinic
P21/n
8.7145(2)
32.4584(8)
18.2551(6)
90
C46H45BrOsP2
929.87
0.31ϫ0.16ϫ0.37
monoclinic
P21/c
17.349(2)
10.7211(10)
20.5972(17)
90
β [°]
91.504(3)
90
5161.8(2)
8
1.924
140(2)
101.101(8)
90
3759.4(7)
4
1.643
100(2)
γ [°]
V [A3]
Z
ρcalcd. [gcm–3]
T [K]
µ [mm–1]
8.114
4.573
θ range [°]
2.64–27.88
12237
12237
semi-empirical
1.00000/0.19163
3.36–27.51
86119
8624
semi-empirical
1.0000/0.7237
8624/0/451
1.242
Reflections collected
Independent reflections
Absorption corrections
Max./min. transmissions
Data/restraints/parameters 12237/0/579
Goodness of fit on F2
1.125
Final R indices [I Ͻ 2σ(I)] R1 = 0.0517,
wR2 = 0.1318
R1 = 0.0297,
wR2 = 0.0494
R1 = 0.0430,
wR2 = 0.0531
0.778/–0.657
R indices (all data)
R1 = 0.0600,
wR2 = 0.1354
4.944/–2.163
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Received: April 8, 2010
Published Online: July 2, 2010
Eur. J. Inorg. Chem. 2010, 3596–3601
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
3601