Organometallic chemistry in supercritical water: Metallorganic products of the CpCo-catalyzed cyclotrimerization of acetylenes

Article abstract of DOI:10.1016/S0022-328X(98)00844-4

Cyclotrimerization of t-butylacetylene or phenylacetylene with CpCo(CO)₂ as catalyst in supercritical water yields the isomeric 1,3,5-tris-substituted- (1: R=Ph, 1a: R=bu^t) and 1,2,4-tris-substituted benzene derivatives (2: R=Ph, 2a: R=bu^t). The identification of the organometallic products obtained under these conditions is described. The formation of all possible isomers of the corresponding CpCo(bis-substituted-cyclobutadiene) (3, 4), CpCo(bis-substituted-CpCobaltacyclopentadiene) (5, 6, 7) and CpCo(bis-substituted-cyclopentadienone) (8, 9, 10) via GC-MS is reported. Two of three isomers of CpCo(bis-substituted-cyclopentadienone) (8, 9 (R=Ph), 8a, 9a (R=bu^t)) were separated and characterized in substance. The structures of 8, 9, 8a and 9a were elucidated by single crystal X-ray diffraction. 8 crystallizes in the orthorhombic space group P2₁2₁2₁ (No.19) with a=840.5(1), b=1105.9(2), c=1767.2(3) pm, V=1642.8(1)×10⁶ pm³, Z=4, D_calc=1.441 g cm^-3, R₁=0.0501 (I>3σ), wR₁=0.0529 (I>3σ). 9 crystallizes in the orthorhombic space group Pna2₁ (No.33) with a=1086.7(1), b=4726.0(1), c=1668.5(1) pm, V=8427.3(1)×10⁶ pm³, Z=20, D_calc=1.404 g cm^-3, R₁=0.0705 (I>2σ), Rw=0.1321 (all data on F²). 8a crystallizes in the monoclinic space group P2₁/c (No. 14) with a=1441.6(3), b=1241.3(1), c=3672.6(6) pm, β=92.39(2)°, V=6566(2)×10⁶ pm³, Z=16, D_calc=1.280 g cm^-3, R₁=0.082 (I>2σ), Rw=0.144 (all data on F²). 9a crystallizes in the monoclinic space group P2₁/c (No. 14) with a=669.3(1), b=1335.7(1), c=1843.1(1) pm,β=94.78(1)°, V=1641.9(1)×10⁶ pm³, Z=4, D_calc=1.28 g cm^-3, R₁=0.0622 (I>2σ), Rw=0.1185 (all data on F²).

Full text of DOI:10.1016/S0022-328X(98)00844-4

Journal of Organometallic Chemistry 570 (1998) 121–127
Organometallic chemistry in supercritical water: metallorganic products
of the CpCo-catalyzed cyclotrimerization of acetylenes
H. Borwieck a, O. Walter a, E. Dinjus a,*, J. Rebizant b
a ITC-CPV, Forschungszentrum Karlsruhe, Postfach 3640, D-76021 Karlsruhe, Germany
b Comission of the European Communities, Joint Research Centre, Institute for Transuranium Elements, Postfach 2340,
D-76021 Karlsruhe, Germany
Received 5 June 1998; received in revised form 26 June 1998
Abstract
Cyclotrimerization of t-butylacetylene or phenylacetylene with CpCo(CO)2 as catalyst in supercritical water yields the isomeric
1,3,5-tris-substituted- (1: R=Ph, 1a: R=but) and 1,2,4-tris-substituted benzene derivatives (2: R=Ph, 2a: R=but). The
identification of the organometallic products obtained under these conditions is described. The formation of all possible isomers
of the corresponding CpCo(bis-substituted-cyclobutadiene) (3, 4), CpCo(bis-substituted-CpCobaltacyclopentadiene) (5, 6, 7) and
CpCo(bis-substituted-cyclopentadienone) (8, 9, 10) via GC-MS is reported. Two of three isomers of CpCo(bis-substituted-cy-
clopentadienone) (8, 9 (R=Ph), 8a, 9a (R=but)) were separated and characterized in substance. The structures of 8, 9, 8a and
9a were elucidated by single crystal X-ray diffraction. 8 crystallizes in the orthorhombic space group P212121 (No.19) with
a=840.5(1), b=1105.9(2), c=1767.2(3) pm, V=1642.8(1)×106 pm3, Z=4, Dcalc=1.441 g cm−3, R1=0.0501 (I\3|),
wR1=0.0529 (I\3|). 9 crystallizes in the orthorhombic space group Pna21 (No.33) with a=1086.7(1), b=4726.0(1), c=
1668.5(1) pm, V=8427.3(1)×106 pm3, Z=20, Dcalc=1.404 g cm−3, R1=0.0705 (I\2|), Rw=0.1321 (all data on F2). 8a
crystallizes in the monoclinic space group P21/c (No. 14) with a=1441.6(3), b=1241.3(1), c=3672.6(6) pm, i=92.39(2)°,
V=6566(2)×106 pm3, Z=16, Dcalc=1.280 g cm−3, R1=0.082 (I\2|), Rw=0.144 (all data on F2). 9a crystallizes in the
monoclinic space group P21/c (No. 14) with a=669.3(1), b=1335.7(1), c=1843.1(1) pm, i=94.78(1)°, V=1641.9(1)×106 pm3,
Z=4, Dcalc=1.28 g cm−3, R1=0.0622 (I\2|), Rw=0.1185 (all data on F2). © 1998 Elsevier Science S.A. All rights reserved.
Keywords: Cyclopentadienyl-Co-complexes; Co-cyclopentadienone-complexes; Supercritical water; Cyclotrimerization of acetyle-
nes
1. Introduction
tion but quite stable in water, even at elevated
temperatures [11]. After treatment with refluxing des-
oxygenated water for several hours more than 98%
CpCo(CO)2 can be recovered.
Supercritical water (SCW, water above 374°C and
221 bar) possesses good solvent properties and has been
used as a non polar extractant for coal [1]. About
synthesis or reactions of organometallics in SCW only
few is reported [2]. CpCo(CO)2 [3–7] is known to
catalyze several reactions, as C–C coupling [8] or C–N
coupling [9,10] agent. E.O. Fischer described Cp-
Co(CO)2 as a very sensitive compound towards oxida-
Jerome and Parsons have shown that cyclotrimeriza-
tion of monosubstituted acetylenes in SCW is catalyzed
by CpCo(CO)2 [2]. We report here the reactions of
monosubstituted acetylenes (R=Ph or but) in SCW,
catalyzed by CpCo(CO)2 in metallic reactors. The main
interest of this work was the isolation, characterization
and quantification of the metallorganic products,
formed in the catalysis in SCW. Further we compare
our results with the mechanism known from the cataly-
sis in organic solvents [12–18].
* Corresponding author. Tel.: +49 7247 822401; fax: +49 7247
822244.
0022-328X/98/$ - see front matter © 1998 Elsevier Science S.A. All rights reserved.
PII S0022-328X(98)00844-4

122
H. Borwieck et al. / Journal of Organometallic Chemistry 570 (1998) 121–127
dienones 8, 9 and 10. These three isomers could also be
formed by reaction of b with further acetylene under
oxidative coupling followed by reductive elimination.
Reductive elimination of e forms the CpCo-cyclobuta-
diene complexes 3 and 4. Coordination of free CpCo-
fragments to e forms the three isomers 5, 6, 7 of
CpCo-cobaltacyclopentadiene complexes.
In detail for the CpCo(CO)2 catalyzed cyclotrimeriza-
tion of phenylacetylene or t-butylacetylene, we iden-
tified the following metallorganic compounds (Fig. 3).
The formation of the metallorganic compounds 3–10
seems to be irreversible, as they do not show catalytic
activity based on the catalytic cycle (Fig. 2). This
assumption is supported by the observation that in the
mixture of the organic products none of the ligands,
coordinated to the CpCo-fragment, or their Diels–
Alder products were found.
Fig. 1. Cyclotrimerization of acetylenes (1, 2 R=Ph, 1a, 2a R=but).
2. Results and discussion
Cyclotrimerization of acetylenes under homogeneous
catalysis in organic solvents has been investigated first
under catalysis of Ni(CO)2(P(Ph)3)2 [19]. Under CpCo-
catalysis we achieved the conversion of acetylenes to
aromats in SCW after heating for 2 h (Fig. 1). The
yields and the relative amounts of the both benzene
isomers are comparable to published results of catalysis
in organic solvents (Table 1) [8,9,12–14]. In the absence
of the catalyst no formation of aromatic ring systems is
observed.
The mechanism of the cyclotrimerization of acetyle-
nes in organic solvents has been discussed [12–18]. The
analysis of the organic and metallorganic products,
found for the cyclotrimerization of acetylenes in SCW,
leads to a mechanism in SCW according to that known
from catalysis in organic solvents.
The composition of the mixture of the metallorganic
products (Fig. 3) has been analyzed by GC-MS and the
characteristic peak for all compounds is the m+/z=
124, corresponding to the CpCo+-cation which can be
generated by fragmentation from 3–10 (Table 2).
Generally the catalytic cyclotrimerizations of the
monosubstituted acetylenes were carried out in the
presence of 3 mol% of CpCo(CO)2. To obtain higher
amounts of the metallorganic products for their isola-
tion special experiments were carried out using two
equivalents of acetylene for one equivalent CpCo(CO)2.
From these experiments first we isolated preparative
yields of the metallorganic compounds 8, 8a, 9, and 9a.
Then quantification occurred by adding a certain
amount of CpCo(butadiene) as external standard and
then via GCMS referring all the peaks of the gas-chro-
matogramm to the peak of the CpCo(butadiene) (Table
2). So for the cyclotrimerization of phenylacetylene 5%
of the CpCo(CO)2 were recovered, and 10% of the
metallorganic compounds were lost because of technical
reasons and 5% reacted to not exactly identified metal-
lorganic compounds. In the case of t-butylacetylene
12% of CpCo(CO)2 were recovered, 10% of metallor-
ganic compounds were lost and 17% of the CpCo(CO)2
reacted to unidentified metallorganic compounds.
The observation of CpCo(CO)2 at the end of the
reaction is due to the unability of the CO to leave the
reactor during the experiment, so it can always be
Under heating CpCo(CO)2, a, may loose a carbonyl
ligand and after coordination of an acetylene unit b can
be formed (Fig. 2). Further cleavage of a Co–CO bond
forms c and coordination of a second acetylene leads to
d. Oxidative coupling submits the CpCobalta-cyclopen-
tadiene, e, which builds
f coordinating another
acetylene unit (Fig. 2). Under insertion of the acetylene-
unit and reductive elimination the benzene derivatives 1
and 2 are formed leaving the remaining CpCo-frag-
ment, g, which is able to close the catalytic cycle by
coordination of a new acetylene unit (Fig. 2).
The central metallorganic compound in the catalytic
cycle is e, because its formation explains all identified
metallorganic products. So e can coordinate a carbon
monoxide, forming h, and further insertion and follow-
ing reductive elimination forms the CpCo-cyclopenta-
Table 1
Quantified GC-MS data of the aromats
Products
Yield (%)
Ret. Time (min)a
m
+/z (%)
1
2
1a
2a
24
71
64
21
34.58
32.70
22.21
19.75
306, 199 (M+); 228, 18 (M+-C6H6); 153, 8 (M2+); 77, 17 (Ph+); 78, 13 (C6H6+
)
306, 100 (M+); 228, 84 (M+-C6H6); 77, 90 (Ph+); 51, 88 (C4H3+
246, 11 (M+); 231, 34 (M+-CH3); 189 8 (M+-C(CH3)3); 57, 100 (C(CH3)3+
246, 11 (M+); 231, 100 (M+-CH3); 57, 91 (C(CH3)3+
)
)
)
1, 2 R=Ph, 1a, 2a R=but. M+symbolizes the the molecule ion.
a Further informations see Section 4.

H. Borwieck et al. / Journal of Organometallic Chemistry 570 (1998) 121–127
123
Fig. 2. Mechanism of the reaction of CpCo(CO)2 with acetylenes. For reasons of clarity the substituents of the monosubstituted acetylenes
(R=Ph or but) are omitted.
Fig. 3. Metallorganic compounds built in the reaction of CpCo(CO)2 with monosubstituted acetylenes. For 3–10 R=Ph, for 3a–10a R=but.
rebuilt by recombination of e.g. CpCo with carbon
monoxide.
The results of the X-ray analyses are shown in Fig. 4.
Table 4 summarizes the crystallographic data [24]. For
8a four molecules are found in the crystallographic
independent unit of the elementary cell, as for 9 five,
respectively. As the independent molecules for 8a and 9
differ mainly in the rotation positions of the residues
bound to the Cyclopentadienone only one is shown in
Fig. 4 as example. The corresponding distances and
angles are listed for all molecules in Table 5.
The substituted cyclopentadienones are in all the
structures bound to the CpCo-fragment in the same way
(Fig. 4). The Co–C(C2, C5)-distances are found to be in
the array of 204–207 pm (Table 5). For the C-atoms in
meta position to the carbonyl group (C3, C4) slightly
shorter Co–C-distances are found (198–202 pm, Table
5) according to a back bonding from the metal atom in
antibonding orbitals of the butadiene unit of the cy-
clopentadienone.
After chromatographic purification 8, 9, 8a, and 9a
1
could be isolated and characterized by H-NMR- and
IR-spectroscopy.
All 1H-NMR-spectra show the characteristic signal at
l=4.65–5.00 for the resonance frequency of the pro-
tons of the Cp-ring (Table 3). All IR-spectra show a
shouldered peak at 1560–1590 cm−1 which is character-
istic for the CꢀO vibration in CpCo-cyclopentadienones
[21,23] (Table 3). The characteristic C–H-valence vibra-
tion of the aromatic rings appears for all four com-
pounds in the region 3057–3092 cm−1. In 8a and 9a the
C–H valence vibration for the but-residue is found
between 2954 and 2960 cm−1 (Table 3).
The four CpCo-cyclopentadienone derivatives (8, 8a,
9, 9a) were crystallized and characterized by single
crystal X-ray diffractometry.

124
H. Borwieck et al. / Journal of Organometallic Chemistry 570 (1998) 121–127
Table 2
GC-MS data of the metallorganic compounds [20–22]
Products
Yield (%)
Ret. time (min)a
m
+/z (%)
3–4
5–7
25
37
31.36, 31.72
39.30, 40.16,
41.25
37.61, 37.65,
37.70
328, 90 (M+); 226, 40 (M+-C8H6); 124, 100 (CpCo+); 59, 37 (Co+
)
452, 100 (M+); 328, 2 (M+-CpCo); 189, 24 (Cp2Co+); 124, 21 (CpCo+); 59, 13 (Co+
356, 100 (M+); 328, 67 (M+-CO); 226, 9 (M+-CO-C8H6); 124, 43 (CpCo+); 59, 35 (Co+
288, 100 (M+); 273, 84 (M+-CH3); 258, 66 (M+-(CH3)2); 243, 20 (M+-(CH3)3); 231, 6 (M+
-
)
8–10
18
26
31
4
)
3a–4a
5a–7a
8a–10a
21.92, 23.34
C(CH3)3); 124, 58 (CpCo+); 59, 44 (Co+
412 100 (M+); 397, 5 (M+-CH3); 382, 11 (M+-(CH3)2); 288, 6 (M+-CpCo); 189, 24 (Cp2Co+);
124, 3 (CpCo+
316, 11 (M+); 301, 43 (M+-CH3); 274, 65 (M+-C3H6); 259, 48 (M+-57); 124, 77 (CpCo); 59,
100 (Co+); 57, 28 (C(CH3)+3
)
30.63, 32.27,
32.30
27.40, 27.80,
27.90
)
)
For 3–10 R=Ph, for 3a–10a R=but. M+symbolizes the molecule ion.
a Isomers of compounds with same mass show similar mass spectra. The retention times are only related to moieties with same mass, their
constitution is not identified.
The coordination of the cyclopentadienone to the
metal causes a folding of the former planar cyclopenta-
dienone, as the interaction of the CpCo-fragment with
the butadiene-unit is stronger than with the CO-part.
The folding angles (angles between the planes once
built from the four carbon-atoms of the butadiene unit
of the cyclopentadienone (C2, C3, C4, C5) and once
built from the oxygen atom and C1, C2, C5 are in the
range of 9–11°.
The folding of the cyclopentadienone-rings is further
expressed in the longer Co–C-distances for the car-
bonyl-C-atoms, which are determined between 223 and
229 pm (Table 5).
The bonding feature of the cyclopentadienone to the
CpCo-fragment is for all the complexes identical to
other compounds of this type [28].
3. Conclusions
We showed here the evidence that metallorganic
chemistry is also possible under extreme conditions as
they are in SCW.
Table 3
1H-NMR- and IR-data of disubstituted CpCo-cyclopentadienones 8,
9, 8a, 9a
For the cyclotrimerization of monosubstituted
acetylenes in SCW under CpCo(CO)2 catalysis we iden-
tified and quantified the metallorganic products and the
results confirm a mechanism, working in SCW, similar
to that in organic solvents.
The possibility to use SCW as a solvent for metallor-
ganic reactions or for catalysis involving metallorganic
compounds is opening the catalytic field for interesting
research on the influence of SCW on these reactions.
Compound 1H-NMR (l)
IR (cm−1
)
C22H17CoO 8.14 (m, 4H, Ph–H, orth)
7.35 (m, 6H, Ph–H, m, p)
3062 m (C–Haromat)
1574 vs (CꢀO)
1446 m (CꢀC)
771 s (Cp)
8
5.53 (s, 2H, Cpon–H)
4.65 (s, 5H, Cp)
C
18H25Co 1.29 (s, 18H, but–H)
4.79 (s, 2H, Cpon–H)
3086 w (C–Haromat
2954 s (C–H, but)
1577 vs (CꢀO)
)
8a
5.03 (s, 5H, Cp–H)
C22H17CoO 8.11 (m, 2H, Ph–H, orth)
3058 m (C–Haromat)
4. Experimental details
7.55 (m, 2H, Ph–H, orth)
1585 vs (CꢀO)
1452 s (CꢀC)
772 s (Cp)
9
7.36 (m, 6H, Ph–H, m, p)
6.02 (s, 1H, Cpon–H)
5.13 (s, 1H, Cpon–H)
4.70 (s, 5H, Cp)
Reagents and analytic details: CpCo(CO)2 (Sigma–
Aldrich) was distilled and stored under Argon in a
Schlenk tube. The monosubstituted acetylenes (Sigma
Aldrich) (R=Ph, but), pentane and dichloromethane
(Merck) were dried using standard methods and all
preparations were carried out using Schlenk techniques.
To get reproducible results the water was heated to
reflux under argon for 48 h prior its use. Alumina, used
for chromatography, was heated (500°C) under vac-
uum. After cooling at room temperature 4% water has
been added to get alumina II.
C18H25CoO 1.18 (s, 9H, but–H)
3092 w (C–Haromat)
1.31 (s, 9H, but–H)
4.29 (s, 1H, Cpon–H)
4.81 (s, 1H, Cpon–H)
5.01 (s, 5H, Cp)
2960 s (C–H, but)
1558 vs (CꢀO)
9a
For 8, 9 R=Ph, for 8a, 9a R=but.

H. Borwieck et al. / Journal of Organometallic Chemistry 570 (1998) 121–127
125
Fig. 4. View to one molecule of 8 (above left), 8a (above right), 9 (down left), 9a (down right) in the crystal.
Reaction extracts in dichloromethane were analyzed
by GCMS-techniques (Hewlett Packard 5890, column
db5, l=30 m, Inj. temp. 250°C, Det. temperature 310°C,
For the catalytic reactions the reactor was filled with
0.25 ml (0.24 g, 2.4 mmol) of phenylacetylene or 0.3 ml
t-butylacetylene (0.2 g, 2.4 mmol) and 0.013 g (0.07
mmol) CpCo(CO)2 (educt:catalyst=35:1) and 3.96 ml
H2O.
To isolate 8 and 9 (8a and 9a) in preparative yields
experiments with higher amounts of CpCo(CO)2 were
carried out. In these experiments we gave to the same
amount of the acetylenes 0.22 g CpCo(CO)2 (educt:
catalyst 2:1) and 3.8 ml H2O in the reactor.
After heating for 2 h and reaction at 380°C and 250
bar pressure, the reactor was cooled at room tempera-
ture and the contents was filled in a Schlenk tube. After
cleaning the reactor with 4 ml dichloromethane the
organic layer and the water mixture were combined and
the water layer were extracted three times with 2 ml
dichloromethane. The organic layer was analyzed by
GCMS-spectroscopy.
After removal of the solvent in vacuum the brown
residue was subjected to chromatography on an alu-
minia column using dichloromethane/methanol (100:1)
mixture as eluant. The eluant has been developed by
chromatography on pre-coated plastic sheets (Machery–
Initial temp. 20°C, Initial time 5 min, Rate 10 °C min−1
,
1
final temperature 300°C, final time 30 min). H-NMR-
spectroscopy of the isolated products were obtained on
a Varian Unity Inova spectrometer in CDCl3 solution
(l=7.27 ppm) at 29°C. The spectra were obtained at the
operating frequency of 400 MHz; 45° pulses were used
with 5 s repetition time. Infrared spectra were recorded
on a BIORAD FT spectrometer in KBr-pellets in the
region of 400–4000 cm−1. For the details of the X-ray
analysis see Table 4.
All reactions in SCW were carried out in a batch
reactor (5 ml) of Inconel 625 under an inert atmosphere
of argon.
The 5 ml-autoklav was filled under conditions of
standard Schlenk techniques. At the beginning the ap-
paratus was heated with a heat gun under vacuum (Fig.
5). The solvent and the reagents were filled under argon
atmosphere and by varying the amount of the solvent
(2.5–4.0 ml) the pressure during the experiment can be
controlled (normal conditions: 380°C, 250 bar).

126
H. Borwieck et al. / Journal of Organometallic Chemistry 570 (1998) 121–127
Table 4
Crystallographic data
Compound
8
8a
9
9a
Empirical formula
Formula weight
Crystal size (mm3)
Crystal system
Space group
Unit cell dimensions
a (pm)
C22H17CoO
356.3
0.45×0.13×0.10
Orthorhombic
P212121 (No. 19)
C
316.3
0.30×0.30×0.15
Monoclinic
P21/c (No. 14)
18H25CoO
C22H17CoO
356.3
0.20×0.30×0.40
Orthorhombic
Pna21 (No. 33)
C18H25CoO
316.3
0.30×0.30×0.30
Monoclinic
P21/c (No. 14)
840.5(1)
1105.9(2)
1767.2(3) pm
1441.6(3)
1241.3(1)
3672.6(6)
92.39(2)
6566(2)×106
16
1086.7(1)
4726.0(1)
1668.5(1)
—
669.3(1)
1335.7(1)
1843.1(1)
94.78(1)
1641.9(1)×106
4
b (pm)
c (pm)
i (°)
—
V (pm3)
1642.8(1)×106
8427.3(1)×106
20
Z
4
Dcalc (g cm¬3
)
1.441
1.280
1.404
1.28
Diffractometer, wavelength
ENRAF-NONIUS CAD4, Mo–Kh,
Graphit-monochromator
295
Siemens SMART 5000 CCD-Diffractometer, Mo–Kh, Graphit-
monochromator
Temperature (K)
Cell parameters on the base 25 (4.45q513.0°)
200
—
200
—
200
—
of reflections
q-Range (°)
ꢀ-Scan
Index ranges
2.05q525.0
2q
−95h58, −135k50, −205l520
1.735q528.46
Dꢀ=0.3°
1.725q528.31
Dꢀ=0.3°
1.895q528.27
Dꢀ=0.3°
−195h519, −165 −145h514, −625 −85h58, −175
k516, −485l548
65 373
16 156
6850 (I]2|)
758
k562, −215l522
85 182
20 658
15 167 (I]2|)
1101
k517, −245l523
16 705
4006
2926 (I]2|)
191
Reflections measured
Independent reflections
Reflections observed
Number of parameters
refined
4746
1665
1176 (I\3|)
218
Residual electron density (e 0.388×10−6
pm−3
0.46×10−6
0.748×10−6
0.594×10−6
)
Corrections
Structure solution
Structure refinement
Programs and weightings
Exp. Absorption correction; „-scan
Direct methods
Full matrix least square on F
Enraf-Nonius SDP-Plus [25]
Lorentz and polarisation, exp. absorption correction
Direct methods
Full matrix least square on F2
SHELX-97 [26], xpma, zortep [27]
used
R indices
R1
0.0501 (I\3|)
0.0529 (I\3|)
0.082 (I\2|)
0.0705 (I\2|)
0.0622 (I\2|)
0.1185 (all data on
F2)
Rw
0.144 (all data on F2) 0.1321 (all data on
F2)
Standard deviations in parenthesis.
Table 5
Selected bond lengths (pm) and angles (°)a
Selected dis-
tances
8
8a
9
9a
Co–C(CO)
Co–C(C2/C5)
222.9(7)
207.3(8)
204.3(7)
198.8(8)
202.8(9)
204.6(9)
−210.0(8)
228.5(5) 227.3(5) 228.8(5) 228.7(5)
207.2(6) 207.6(6) 206.9(6) 207.2(6)
207.4(5), 207.4(5), 207.5(5), 207.9(5)
198.6(6) 198.8(5) 198.9(5) 199.5(6)
198.7(5), 199.2(5), 199.3(5), 200.0(5)
204.7(6), −206.3(6)
226.1(5), 224.3(5), 227.7(6), 225.6(5), 225.0(5)
204.5(5), 207.1(5), 203.9(5), 205.3(5), 203.8(5)
206.1(5), 204.6(5), 206.4(5), 203.9(5), 205.7(5)
199.0(5), 200.6(5), 199.0(5), 201.5(5), 197.9 (5)
199.9(5), 198.2(5), 201.2(5), 199.4(5), 201.5(5)
203.6(6), −205.5(6)
227.2(4)
205.7(3)
206.7(3)
198.5(3)
201.7(3)
202.4(4)
−204.1(4)
Co–C(C3/C4)
Co–C(Cp)
204.9(6), −206.9(6)
201.5(5), −205.2(5)
203.8(6), −206.3(5)
200.8(7), −204.8(8)
203.5(6), −206.4(6)
203.9(6), −205.7(5)
C(CO)–O
Selected angles
C–C(CO)–C
126.5(9)
105.1(7)
125.6(6), 126.5(6), 123.9(6), 124.6(6)
124.7(6), 125.5(6), 124.1(7), 125.5(7), 127.4(6)
125.5(4)
104.4(3)
104.8(5), 105.6(5), 104.5(4), 104.5(4)
104.0(4), 103.9(4), 103.4(5), 104.2(5), 104.5(4)
a Numbers in parentheses are estimated standard deviations in the last significant digit. As for 8a four crystallographic independent molecules and
for 9 five are found in the elementary cell, in the table for 8a there are four given values as for 9 five, respectively.

H. Borwieck et al. / Journal of Organometallic Chemistry 570 (1998) 121–127
127
[4] F.A. Cotton, A.D. Liehr, G. Wilkinson, J. Inorg. Nucl. Chem. 1
(1955) 175.
[5] B. Beagley, C.T. Parrot, V. Ulbrecht, G.G. Young, J. Mol.
Struct. 52 (1979) 47.
[6] M. Yu Antipin, Y.T Struchkov, A.N. Chernega, M.F. Meidine,
J.F. Nixon, J. Organomet. Chem. 436 (1992) 79.
[7] I.R. Lyatifov, G.M. Jafarov, V.N. Babin, P.V. Petrovskii, V.D.
Zagorevskii, J. Organomet. Chem. 368 (1989) 223.
[8] M.D. Rausch, R.A. Genetti, J. Org. Chem. 35 (1970) 3888.
[9] H. Boennemann, W. Brijoux, R. Brinkmann, W. Meurers, R.
Mynott, J. Organomet. Chem. 272 (1984) 231.
[10] H. Boennemann, W. Brijoux, R. Brinkmann, W. Meurers, Helv.
Chim. Acta 67 (1984) 1616.
[11] E.O. Fischer, R. Jira, Z. Naturforsch. B 10 (1955) 355.
[12] H. Boennemann, W. Brijoux, N. J. Chem. 11 (1987) 549.
[13] H. Boennemann, R. Brinkmann, H. Schenkluhn, Synthesis
(1974) 575.
Fig. 5. Schematic view of the batch reactor with thermoelement T1,
manometer P1, burst window (392 bar), pump and argon supply.
[14] H. Boennemann, Angew. Chem. 97 (1985) 264; Int. Ed. Engl. 24
(1985) 248.
[15] K.P.C. Vollhardt, Angew. Chem. 96 (1984) 525; Int. Ed. Engl.
23 (1984) 539.
[16] K.P.C. Vollhardt, Acc. Chem. Res. 10 (1977) 1.
[17] K.P.C. Vollhardt, Pure Appl. Chem. 65 (1993) 153.
[18] H. Yamazaki, Y. Wakatsuki, Tetrahedron Lett. 36 (1973) 3383.
[19] W. Reppe, N.V. Kutepow, A. Magin, Angew. Chem. 81 (1969)
717; Int. Ed. Engl. 8 (1969) 727.
[20] M. Rosenblum, B. North, J. Am. Chem. Soc. 90 (1968) 1060.
[21] R.S. Dickson, H.P. Kirsch, Aust. J. Chem. 26 (1973) 1911.
[22] J.F. Helling, S.C. Rennison, A. Merijan, J. Am. Chem. Soc. 89
(1967) 7140.
Nagel, 40×80 mm, polygram alox N/UV254). This
procedure yields in case of R=Ph (educt:cat 2:1) the
dark red 8 (Rf=0.5; 20 mg, 0.06 mmol, yield 5.6%) and
the red 9 (Rf=0.25; 36 mg, 0.1 mmol, yield 9.4%), in
case of R=but (educt:cat 2:1) the dark yellow 8a
(Rf=0.4; 3.8 mg, 0.012 mmol, yield 1.2%) and yellow
9a (Rf=0.2; 5.7 mg, 0.018 mmol, yield 1.8%) [21,23]. 8
and 9 were crystallized under vacuum sublimation to
red crystals. For 8a and 9a crystals were grown from a
pentane solution by slow diffusion of the solvent at r.t.
[23] R.S. Dickson, S.H. Johnson, J.D. Rae, Aust. J. Chem. 28 (1975)
1681.
Acknowledgements
[24] For more detailled informatin please contact the FIZ, Hermann-
von Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen,
Germany, mentioning the CSD numbers 391062 (8), 391063 (8a),
391064 (9), 391064 (9a), the authors and the citation.
[25] Enraf-Nonius SDP-Plus, Structure Determination Package, En-
raf-Nonius, Delft, Netherlands, 1987.
We thank Dr Chr. Apostolitis and E. Dornberger for
their help in growing crystals and their support in
preparative chemistry. We are also very grateful to R.
Will for the GC-MS analytical data and Dr F. Gaßner
for the measurement of the NMR spectra.
[26] SHELX-97, G.M. Sheldrick, Universita¨t Go¨ttingen, Go¨ttingen,
1997.
[27] xpma, zortep, L. Zsolnai, Universita¨t Heidelberg, Heidelberg,
1997.
References
[28] (a) A. Clearfield, P. Rudolf, I. Bernal, M.D. Rausch, Inorg.
Chim. Acta 42 (1980) 17. b) J.H. Bieri, A.S. Dreiding, T.C.C.
Gartemann, E.R.F. Gesing, R.W. Kunz, R. Prewo, J.
Organomet. Chem. 306 (1986) 241. (c) R. Boese, D. Blaser, R.L.
Haltermann, K.P.C. Vollhardt, Angew. Chem. 100 (1988) 594;
Int. Ed. Engl. 27 (1988) 553.
[1] P. Missal, K. Hedden, Chemie-Technik 19 (1990) 56.
[2] K.S. Jerome, E.J. Parsons, Organometallics 12 (1993) 2991.
[3] T.S. Piper, F.A. Cotton, G. Wilkinson, J. Inorg. Nucl. Chem. 1
(1955) 165.
.