Comparison between a diarylferrocenylmethylium ion and its isolobal cobalt species: Similarities and differences

Article abstract of DOI:10.1021/om960694d

Reaction of {(1,2,8,9-η)-tricyclo[7.5.0.0^1,7]tetradeca-1,8-diene}{η ⁵-(methoxycarbonyl)-cyclopentadienyl}cobalt (9) with either 2 mol of arylmagnesium bromide or aryllithium and subsequent hydrolysis yields the alcohols {(1,2,8,9-η)tricyclo[7.5.0.0^1,7]tetradeca-1,8-diene}-{η ⁵-(diarylhydroxymethyl)cyclopentadienyl}cobalt (13a-c). The treatment of the yellow colored alcohols 13a-c with HBF₄ in ether affords the tetrafluoroborates of the violet colored carbocations 14a-c. Investigations of single crystals of 14b by means of the X-ray technique show a displacement of the C₁-C_exo bond by α = 10.8° toward the metal and a pronounced bond alternation in the fulvene moiety. The bending of C₁-C_exo is considerably larger than in the corresponding alcohol 13b (α = 2.5°). The interaction between the exo-carbon and the metal in 14b is further substantiated by comparison of the ¹³C-NMR chemical shift of 14b with 13b (Δδ = -65 ppm). The comparison of the data obtained for 14b with those of diphenylferrocenylcarbenium ion 1b suggests a stronger bonding between metal and fulvene moiety in 1b as compared to 14b. These results are substantiated by the results of ab initio calculations on 1b and 4a which show a smaller positive charge at the exo-carbon in 4a than in 1b and a stronger bond index between the exo-carbon and the metal in 1b as compared to 4a.

Full text of DOI:10.1021/om960694d

Organometallics 1996, 15, 5635-5640
5635
Com p a r ison betw een a Dia r ylfer r ocen ylm eth yliu m Ion
a n d Its Isoloba l Coba lt Sp ecies: Sim ila r ities a n d
Differ en ces
Rolf Gleiter,*,† Holger Schimanke,† Sandro J . Silverio,† Michael Bu¨chner,‡ and
Gottfried Huttner‡
Organisch and Anorganisch Chemisches Institut der Universita¨t Heidelberg,
Im Neuenheimer Feld 270, D 69120 Heidelberg, Germany
Received August 13, 1996X
Reaction of {(1,2,8,9-η)-tricyclo[7.5.0.01,7]tetradeca-1,8-diene}{η5-(methoxycarbonyl)-
cyclopentadienyl}cobalt (9) with either 2 mol of arylmagnesium bromide or aryllithium and
subsequent hydrolysis yields the alcohols {(1,2,8,9-η)tricyclo[7.5.0.01,7]tetradeca-1,8-diene}-
{η5-(diarylhydroxymethyl)cyclopentadienyl}cobalt (13a -c). The treatment of the yellow
colored alcohols 13a -c with HBF4 in ether affords the tetrafluoroborates of the violet colored
carbocations 14a -c. Investigations of single crystals of 14b by means of the X-ray technique
show a displacement of the C1-Cexo bond by R ) 10.8° toward the metal and a pronounced
bond alternation in the fulvene moiety. The bending of C1-Cexo is considerably larger than
in the corresponding alcohol 13b (R ) 2.5°). The interaction between the exo-carbon and
the metal in 14b is further substantiated by comparison of the 13C-NMR chemical shift of
14b with 13b (∆δ ) -65 ppm). The comparison of the data obtained for 14b with those of
diphenylferrocenylcarbenium ion 1b suggests a stronger bonding between metal and fulvene
moiety in 1b as compared to 14b. These results are substantiated by the results of ab initio
calculations on 1b and 4a which show a smaller positive charge at the exo-carbon in 4a
than in 1b and a stronger bond index between the exo-carbon and the metal in 1b as
compared to 4a .
Ch a r t 1
In tr od u ction
The remarkable stability of ferrocenylcarbocations (1)
(Chart 1) has been demonstrated extensively by a
number of structural studies1-3 and physicochemical
measurements.4,5 It has been agreed that the stability
of 1 is due to a sizable interaction of the exo-carbon of
the fulvene moiety and the metal. This could be traced
back to the interaction of the LUMO of the fulvene
moiety with the 3dz orbital of the metal.6
2
There are many studies of systems like 11 and some
studies of the isolobal neutral systems 27,8 and 3,9 but
only one investigation is known to us of a substituted
(η5-cyclopentadienyl)(η4-cyclobutadiene)cobalt carbo-
cation system. Seyferth and Merola have prepared 4b,10
† Organisch Chemisches Institut.
‡ Anorganisch Chemisches Institut.
X Abstract published in Advance ACS Abstracts, November 15, 1996.
(1) Reviews: Watts, W. E. Organomet Chem. Rev. 1979, 7, 399. Cais,
M. Ibid. 1966, 1, 435.
(2) Cais, M.; Dani, S.; Herbstein, F. H.; Kapon, M. J . Am. Chem.
Soc. 1978, 100, 5554. Sime, R. L.; Sime, R. J . J . Am. Chem. Soc. 1974,
96, 892.
(3) Behrens, U. J . Organomet. Chem. 1979, 182, 89.
(4) Hill, E. A.; Wiesner, R. J . Am. Chem. Soc. 1969, 91, 509.
Nesmeyanov, A. N.; Kazakova, L. I.; Reshetova, M. D.; Kazitsina, L.
A.; Perevalova, E. G. Izv. Akad. Nauk. SSSR, Ser. Khim. 1970, 2804.
Turbitt, T. D.; Watts, W. E.; J . Chem. Soc., Perkin 2 1974, 185.
(5) Gleiter, R.; Seeger, R.; Binder, H.; Fluck, E.; Cais, M. Angew.
Chem. 1972, 84, 1107; Angew. Chem., Int. Ed. Engl. 1972, 11, 1028.
(6) Gleiter, R.; Seeger, R. Helv. Chim. Acta 1971, 54, 1217.
(7) Lubke, B.; Behrens, U. J . Organomet. Chem. 1978, 149, 327.
(8) Adrianov, V. G.; Struchkov, Y. T.; Setkina, V. N.; Zdanovich, V.
I.; Zhakaeva, A. Z.; Kursanov, D. N. J . Chem. Soc., Chem. Commun.
1975, 117.
whose 13C NMR spectrum indicates an interaction
between the exo carbon and the metal. In this paper
we present solid evidence for an interaction between
cobalt and the cationic center and discuss the isolobal
relation between the CpFe+ and the CbCo+ fragments
(Cp ) η5-cyclopentadienyl, Cb ) η4-cyclobutadienyl).
(9) Appel, A.; J a¨kle, F.; Priermeier, T.; Schmid, R.; Wagner, M.
Organometallics 1996, 15, 1188.
(10) Seyferth, D.; Merola, J . S. J . Organomet. Chem. 1978, 160, 275.
S0276-7333(96)00694-2 CCC: $12.00 © 1996 American Chemical Society

5636 Organometallics, Vol. 15, No. 26, 1996
Gleiter et al.
Sch em e 1
Ta ble 1. Con d ition s for th e F or m a tion a n d
Solu bilities of th e Ca tion ic Com p ou n d s 14a -c
F igu r e 1. Comparison between the electron absorption
spectra of 13b and 14b in CH2Cl2.
HBF4
HPF6
HClO4
compd
in ether
CF3COOH
in water
in water
14a (R ) H)
precipitate solution
solution
solution
decomposn decomposn
decomposn
solution
14b (R ) CH3) precipitate solution
14c (R ) F)
solution
solution
Resu lts a n d Discu ssion
{(1,2,8,9-η)-Tr icyclo([7.5.0.01,7]tetr adeca-1,8-dien e}-
{η5-(d ia r y lh y d r o x y m e t h y l)c y c lo p e n t a d ie n y l}-
coba lt. The reason for the lack of investigations on the
cobalt systems might be the comparatively difficult
access to systems such as 4. Our recent work on the
reaction between cyclic diynes and CpCoL2 species has
resulted in easy access to {(1,2,8,9-η)-tricyclo[7.5.0.01,7]-
tetradeca-1,8-diene}{η5-(methoxycarbonyl)cyclopenta-
dienyl}cobalt (9) as a suitable precursor for cationic
cobalt species as shown in Scheme 1.11 The synthesis
of this carboxylic ester commenced with an intramo-
lecular [2 + 2] cycloaddition of the two triple bonds in
cyclotetradeca-1,8-diyne (7),12 mediated by the cobalt of
8, to afford 9 in 21% yield. To synthesize the unsub-
stituted cobaltocenium compound 11, 9 can easily be
converted into the primary alcohol {(1,2,8,9-η)-tricyclo-
[7.5.0.01.7]tetradeca-1,8-diene}{η5-(diarylhydroxymethyl)-
cyclopentadienyl}cobalt (10) via reduction with LiAlH4
in 96% yield, followed by hydrolysis, as shown in
Scheme 2. After treatment with acid only pentafulvene
12 could be isolated as a resulting product of the
decomposition of 11. We solved the problem of the
obvious instability of 11 by using para-substituted
benzene rings to stabilize the carbocationic center. The
reaction of the latter with aryllithium or Grignard
reagents resulted in the formation of the tertiary
alcohols with R ) hydrogen, methyl, and fluorine (13a -
c) in 57-87% yield after hydrolysis. We also tried the
syntheses of the methoxy-, thiomethyl-, trifluoromethyl-,
and N,N-dimethyl-substituted compounds but observed
only the correspondig fulvenes or decomposition of the
starting material.
F igu r e 2. Cyclovoltammograms of 14a (top) and 14b
(bottom) in CH2Cl2 vs SCE, at 272 K, scan rate 200 mV (s,
E ) -785 mV (14a ) and -368 mV (14b)).
(diarylmethylium)cyclopentadienyl}cobalt compounds
14a -c could be observed, but only in case of the
tetrafluoroborates 14a ,b was a dark violet solid pre-
cipitated that could be filtered and recrystallized. In
Figure 1 the electron absorption spectrum of 14b is
compared with that of 13b, demonstrating a consider-
able bathochromic shift of the long wavelength absorp-
tion band. The shift is due to the more extended
π-system in 14, compared to 13. As expected for
carbocationic compounds, 14a ,b could be easily reduced
by means of cyclovoltammetry. Figure 2 shows the
potentials, which could be interpretated as reversible
one-electron oxidations.
{(1,2,8,9-η)-Tr icyclo[7.5.0.01,7]tetr adeca-1,8-dien e}-
{η5 -( d i a r y l h y d r o x y m e t h y l i u m ) c y c l o p e n t a -
d ien yl}coba lt Sa lts. Treatment of the yellow colored
alcohols, dissolved in ether, with different acids led to
an immediate change to a deep blue-violet colored
solution. As shown in Table 1, the formation of the
{(1,2,8,9-η)-tricyclo[7.5.0.01.7]tetradeca-1,8-diene}{η5-
To elucidate the structural parameters of the cationic
compounds, single crystals of 14b were grown and
investigated by means of X-ray crystallography. The
(11) Gleiter, R.; Pfla¨sterer, G. Organometallics 1993, 12, 1886.
(12) Gleiter, R.; Merger, R.; Treptow, B.; Wittwer, W.; Pfla¨sterer,
G. Synthesis 1993, 558.

A Diarylferrocenylmethylium Ion and Its Co Analog
Organometallics, Vol. 15, No. 26, 1996 5637
Sch em e 2a
a
Key: (a) LiAlH4/THF, H2O; (b) HBF4/ether; (c) PhMgBr, H2O; (d) Li(C6H4)R, H2O.
Ta ble 2. Cr ysta l Da ta a n d Da ta Collection
P a r a m eter s of 13b a n d 14b
13b
14b
mol formula
fw
C34H39CoO
522.58
C34H38BCoF4
592.42
cryst syst
space group
cell dimens
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
monoclinic
P21/n (No. 14)
triclinic
P1h (No. 2)
9.786
19.991
13.983
90.00
98.72
90.00
2703.9
4
1.284
0.659
1112
200
13.774
14.057
15.401
92.05
94.31
100.07
2924.10
4
Z
d
F igu r e 3. ORTEP drawing of 14b. The core atoms are
labeled. Ellipsoids are at the 50% probability level, and
hydrogens atoms have been omitted for the sake of clarity.
calc, g‚cm-3
1.355
0.635
1248
abs coeff, mm-1
F(000)
T, K
200
radiation, Å
scan type
reflns measd
λ(Mo KR)
λ(Mo KR)
ω
ω
h, 0 to 10; k, -21 to h, -8 to 17; k, -17 to
0; l, -15 to 15
3.679-46.00
17; l, 19 to 19
2θ range, deg
no. of reflns measd 4015
2.7-54.00
13 303
746
0.0854
0.247
1.041
no. of params
R(F)
481
0.0431
0.116
0.996
Rw(F2)
GOF on F2
compared the parameters R, â, and d (defined in 56) in
1b, 2b, 14b, and 14b′. In all three cases there is clearly
an interaction between the exo-carbon and the metal.
This interaction is also indicated by comparison of the
difference in the 13C-NMR chemical shift of the exo-
methylene carbon between the alcohols 6 and 13b and
the corresponding carbenium ions 1b and 14b,
respectively: ∆δ(6 - 1b) ) -71 ppm, ∆δ(13b - 14b) )
-65 ppm. The structural parameters in Table 4 point
to a decreased metal-carbon interaction in 14b, as
compared to 2b and 1b. This might be at least in part
due to steric interactions between the exo C(C7H7)2
group and the pentamethylene chains in 14b.
In order to compare the interaction between the 6,6′-
diphenylfulvene ligandsespecially the interaction be-
tween the exo-methylene carbonsand M (M ) Fe (1b);
M ) Co (14b)), we have carried out restricted Hartree-
Fock ab initio calculations on 1b and 4a , as well as on
their fragments CpFe+ and CbCo+. 4a is a model
F igu r e 4. ORTEP drawing of 13b. The core atoms are
labeled. Ellipsoids are at the 50% probability level, and
hydrogens atoms have been omitted for the sake of clarity.
resulting structure is shown in Figure 3. The most
striking features of 14b are a displacement of the C1-
Cexo bond by R ) 10.8° (as defined in 56) toward the
metal and pronounced bond alternation in the fulvene
moiety. The bending in 14b is considerably larger than
in alcohol 13b (R ) 2.3°), from which we have also grown
single crystals. Figure 4 shows the structure of the
alcohol 13b. The most relevant X-ray crystallographic
data obtained are given in Tables 2 and 3, containing
also the data of the second independent molecule 14b′
found in the elementary cell. In Table 4 we have

5638 Organometallics, Vol. 15, No. 26, 1996
Gleiter et al.
that the positive charge of the CbCo+ fragment is more
distributed over the Cb ring, while the positive charge
of the CpFe+ fragment remains at the iron atom. This
is in good agreement with the 13C-NMR spectra. The
calculated Wiberg bond indices (wbi) between the iron
atom and the carbon atoms in the Cp ring of CpFe+ are
0.28 and are considerably smaller than the correspond-
ing Wiberg bond indices between the cobalt atom and
the carbon centers (wbi ) 0.42) in the Cb ring of CbCo+.
Both results point to a stronger bonding of the cobalt
atom with the Cb moiety in the CbCo+ fragment as
compared to the iron atom with the Cp ligand in the
CpFe+ fragment.
If we compare now the natural charges at the metal
centers of 1b and 4a , we find a smaller charge at the
iron species (+0.54) as compared to the cobalt compound
(+0.68). Thus more electron density is transferred from
the diphenylfulvene ligand in 1b to the CpFe+ fragment
(0.70 e) than to the CbCo+ fragment (0.24 e) in 4a . The
calculations on 1b predict 85% of the positive charge to
be at iron and the exo-methylene carbon; in the case of
4a 96% of the positive charge is found on cobalt and
the exo-methylene carbon. The positive charge at the
exo-methylene carbon is smaller in 4a (+0.28) than in
1b (+0.31). The Wiberg bond index between the metal
and exo-methylene carbon center of the 6,6′-diphenyl-
fulvene ligand is smaller in the case of 4a (wbi ) 0.016)
compared to 1b (wbi ) 0.061). These findings are in a
good agreement with the shorter Fe-C(exo) distance
and the larger bond angle (R) (Table 4) in 1b as
compared to the corresponding values for 14b. Thus
the stronger metal-fulvene interaction in 1b as com-
pared to 4a is due to a higher stability of the CbCo+
moiety with respect to the CpFe+ fragment. This
difference in the stability can be traced back to the
stronger bonding of the cobalt atom with the Cb ligand
and a better distribution of the positive charge in the
CbCo+ fragment over the Cb ring as compared to the
CpFe+ fragment.
Ta ble 3. Selected In ter a tom ic Dista n ces (Å) for
13b a n d 14b
Compound 13b
Co-C1
Co-C2
Co-C3
Co-C4
Co-C15
Co-C16
Co-C17
Co-C18
2.003(4)
1.977(4)
1.989(4)
2.012(4)
2.077(4)
2.077(4)
2.079(4)
2.083(4)
Co-C19
2.086(4)
1.522(5)
1.420(6)
1.405(6)
1.434(6)
1.422(5)
1.431(5)
C19-C20
C15-C16
C16-C17
C17-C18
C18-C19
C15-C19
Compound 14b
Co1-C1
Co1-C2
Co1-C3
Co1-C4
Co1-C15
Co1-C16
Co1-C17
Co1-C18
1.996(6)
2.010(7)
2.003(6)
2.002(6)
2.086(6)
2.104(6)
2.108(6)
2.077(7)
Co1-C19
C19-C20
C15-C16
C16-C17
C17-C18
C18-C19
C15-C19
2.085(6)
1.411(9)
1.396(9)
1.425(10)
1.377(9)
1.479(9)
1.441(9)
Ta ble 4. Selected Geom etr ica l P a r a m eter s for 1b
a n d th e Isoloba l Sp ecies 2b, 14b, a n d 14b
compd
R (deg)
â (deg)
d (Å)
ref (Å)
2b
1b
14b
14b′
31.0
20.7
10.8
6.4
2.55
8.1
12.4
13.4
9
2.72
2.95
3.03
3
this work
this work
Ta ble 5. Na tu r a l Ch a r ges a n d Wiber g Bon d
In d ices of Selected Atom s a n d F r a gm en ts in 1b
a n d 4a
Natural Charges
atom
CpFe+
1b
CbCo+
4a
Fe
Co
+1.24
+0.54
+0.92
+0.68
+0.28
Cexo
+0.31
Wiberg Bond Indices
bond
CpFe+
1b
CbCo+
4a
Fe-Cexo
Co-Cexo
0.061
0.016
compound for 14b, in which the tricyclo[7.5.0.01.7]-
tetradeca-1,8-diene ligand is replaced by a simple cyclo-
butadiene (Cb) ligand. Our results refer to the singlet
state of the Hartree-Fock wave functions of 4a , 14b,
CpFe+, and CbCo+.
Pseudopotentials were employed for inner shell elec-
trons of Fe and Co, which have been developped by Hay
and Wadt.13 The valence orbitals, and the outermost
core orbitals, were treated as a Gaussian orbital basis
set (3s, 4s, 3p, 4p, 3d). The valence orbitals are
contracted to a double-ê basis. Respective basis sets of
(10s, 5p) and (4s) were used for carbon and hy-
drogen and contracted to a split-valence. The geo-
metrical parameters adopted for the calculations were
those determined by the X-ray investigations of 1b7 and
14b.
The natural charges at the metal center and at the
exo-methylene carbon atom in 1b and 4a and at the
metal centers in the isolobal CpFe+ and CbCo+ frag-
ments are compared in Table 5. Consider first the
CpFe+ and the CbCo+ fragments. In these fragments
the charges at the metal centers are computed to be
+1.24 (Fe) and +0.92 (Co), respectively. This indicates
Con clu sion
Although 1b and 14b are isolobal species, there is a
considerable difference between them. We ascribe this
difference to the stronger interactions between fulvene
and the CpFe+ fragment compared to the CbCo+ frag-
ment, due to a higher stability of the CbCo+ fragment.
Exp er im en ta l Section
Equ ip m en t. All melting points are uncorrected. The NMR
spectra are measured with a Bruker AS200 or AS300 (1H-NMR
at 200 or 300 MHz and 13C-NMR at 50.32 or 75.45 MHz) using
the solvent as internal standard (δ; J (Hz)). IR spectra were
recorded with an Perkin-Elmer 580 B. UV light absorption
data were recorded using a Hewlett Packard 8452A spectrom-
eter. Cyclovoltammograms were collected on a HEKA PG 28
potentiostat vs SCE in a 0.1 M solution of (n-Bu)4NPF6 in
CH2Cl2. The potential of the ferrocene/ferrocenyl system was
recorded at 487 mV vs SCE. Elemental analyses were
performed at the Mikroanalytisches Labor der Universita¨t
Heidelberg. All reactions were carried out in argon atmo-
sphere using dried oxygen-free solvents.
{(1,2,8,9-η)-Tr icyclo[7.5.0.01.7]t et r a d eca -1,8-d ien e}{η5-
(h yd r oxym eth yl)cyclop en ta d ien yl}coba lt (10). To a sus-
pension of 379 mg (10 mmol) of LiAlH4 in 500 mL of
tetrahydrofuran was added dropwise 1.85 g (5 mmol) of 9
dissolved in 28 mL of tetrahydrofuran. After the mixture was
stirred for 4 h, 250 mL of a saturated NaCl solution in water
(13) a. Hay, P. J .; Wadt, W. R. J . Chem. Phys. 1985, 82, 270. (b)
Hay, P. J .; Wadt, W. R. J . Chem. Phys. 1985, 82, 284. (c) Hay, P. J .;
Wadt, W. R. J . Chem. Phys. 1985, 82, 299.

A Diarylferrocenylmethylium Ion and Its Co Analog
Organometallics, Vol. 15, No. 26, 1996 5639
1
was added, the layers were separated, and the aqueous layer
was extracted with ether. The combined organic layers and
extracts were dried with MgSO4, concentrated in vacuo, and
absorbed on Celite. The product was purified by column
chromatography (alumina, 6% water/2:3 ether-n-pentane) and
yielded 1.63 g (96%) of 10a as a yellow solid. 10a : Mp 129
°C; 1H-NMR (300 MHz, CDCl3) δ ) 4.95-4.93 (m; J ) 2.0 Hz;
2H), 4.69-4.67 (m; J ) 2.0 Hz; 2H), 4.30-4.28 (d; J ) 5.6 Hz;
2H), 2.00-1.92 (m; 10H), 1.69 (m; 8H); 1.27-1.23 (t; J ) 5.6
Hz; 1H), 0.95-0.87 (m, 2H); 13C-NMR (75.4 MHz, CD2Cl2) δ
) 97.0 (C), 79.9 (CH), 79.6 (CH), 79.0 (C), 60.0 (CH2), 30.6
(CH2), 30.4 (CH2), 27.8 (CH2); UV (n-pentane) λmax [nm (log
ꢀ)] ) 212 (4.13), 266 (4.21), 348 (2.54); IR (KBr) 2916, 2840,
°C (dec); H-NMR (300 MHz, CDCl3) δ ) 7.32-7.25 (m; 4H),
6.95-6.89 (m, 4H), 4.83-4.82 (m; J ) 2.1; 2H), 4.61-4.60 (m;
J ) 2.1; 2H), 2.84 (s; 1H), 1.98-1.83 (m, 12H), 1.66-1.56 (m;
2H), 1.26-1.13 (m;4H); 0.88-0.80 (m, 2H); 13C-NMR (75,4
MHz, CD2Cl2) δ ) 163.5 (C), 160.3 (C), 143.9 (C), 128.9 (CH),
128.8 (CH), 114.5 (CH), 114.2 (CH), 108,6 (C), 81.2 (C), 81.1
(CH), 79.7 (CH), 76.7 (C), 31.1 (CH2), 30.5 (CH2), 28.2 (CH2);
UV (CHCl3) λmax [nm (log ꢀ)] ) 246 (4.04), 268 (4.32), 306 (3.19),
378 (2.70); IR (KBr) 3493, 2920, 1601, 1504, 1223, 1152, 828,
807, 572. HRMS (EI, 70 eV) calcd for C32H33CoF2O m/ z
530.1831, found m/ z 530.1790.
1-(Dip h en ylh yd r oxym eth yl)fer r ocen e (6). To a solution
of 1.05 g (2.5 mmol) of 1-(chloromercurio)ferrocene in 50 mL
of ether was added dropwise 3.9 mL of a 1.6 M solution of
n-butyllithium at room temperature. The mixture became
homogeneous and turned deep red. The solution was stirred
for 30 min, and then 910 mg (5 mmol) of benzophenone was
added. The reaction mixture was stirred for an additional 30
min and then quenched with 50 mL of water. The layers were
separated, and the aqueous layer was extracted with ether.
The combined organic layers and extracts were washed with
saturated NaHCO3 solution, dried over MgSO4, concentrated
in vacuo, and absorbed on Celite. The product was purified
by column chromatography (alumina, 6% water/1:20 ether-
n-pentane) and yielded 818 mg (93%) of 6 as a yellow solid. 6:
1H-NMR (300 MHz, CDCl3) δ ) 7.31-7.25 (m; 10H), 4.29-
4.27 (m; J ) 1.9 Hz; 2H), 4.19 (s; 5H), 4.05-4.05 (m; J ) 1.9
Hz; 2H), 3.48 (s; 1H); 13C-NMR (75,4 MHz, CDCl3) δ ) 146.96
(C), 127.44 (CH), 127.01 (CH), 126.72 (CH), 99.37 (C), 77.35
(C), 68.69 (CH), 68.55 (CH), 68.35 (CH).
{(1,2,8,9-η)-Tr icyclo[7.5.0.01.7]t et r a d eca -1,8-d ien e}{η5-
(d ip h en ylm et h yliu m )cyclop en t a d ien yl}cob a lt Tet r a -
flu or obor a te (14a ). To a solution of 100 mg (0.20 mmol) of
13a in 5 mL of ether was added 0.2 mL of a 54% tetra-
fluoroboric acid solution in ether at 0 °C. The yellow color
instantly changed to deep violet. After stirring of the mixture
for an additional 30 min at 0 °C, the precipitate was filtered
out and recrystallized from ether/n-pentane at -10 °C. A 91
mg (0.16 mmol) amount of a deep violet solid was obtained in
80% yield. 14a : Mp 168 °C (dec); 1H-NMR (300 MHz, CDCl3,
223 K) δ ) 7.72-7.10 (m; 10H), 6.10 (m; 2H), 5.86 (m; 2H),
1.85-1.60 (m; 14H), 1.32-0.74 (m; 6H); 13C-NMR (75.4 MHz,
CDCl3, 223 K): δ ) 170.58 (C), 140.27 (C), 132.67 (CH), 131.85
(CH), 129.09 (CH), 110.78 (C), 103.45 (CH), 99.40 (C), 84.79
(CH), 29.84 (CH2), 28.00(CH2), 27.25 (CH2); UV (CH2Cl2) λmax
[nm (log ꢀ)] ) 220 (4.38), 256 (4.41), 3.62 (4.42), 589 (4.01); IR
(KBr) 3412, 2916, 2846, 1440, 1121, 1081, 697; HRMS (FAB+)
calcd for C32H34Co m/ z 477.1992, found m/ z 477.2033.
{(1,2,8,9-η)-Tr icyclo[7.5.0.01.7]t et r a d eca -1,8-d ien e}{η5-
( b i s ( p -m e t h y l p h e n y l ) m e t h y l i u m ) c y c l o p e n t a d i -
en yl}coba lt Tetr a flu or obor a te (14b). To a solution of 100
mg (0.19 mmol) of 13b in 5 mL of ether was added 0.2 mL of
54% tetrafluoroboric acid solution in ether at 0 °C. The
working up procedure was carried out as described for 14a
yielding 104 mg (0.17mmol) (89%) of 14b as deep violet
2810, 1440, 1325, 1036; HRMS (EI, 70 eV) calcd for C20H27
-
CoO m/ z 342.1394, found m/ z 342.1382.
{(1,2,8,9-η)-Tr icyclo[7.5.0.01.7]t et r a d eca -1,8-d ien e}{η5-
(d ip h en ylh yd r oxym eth yl)cyclop en ta d ien yl}coba lt (13a ).
To a solution of 1.5 g (4.05 mmol) of 9 in 100 mL of
tetrahydrofuran, cooled to -78 °C, was added 6.1 mL of a 2 M
phenyllithium solution in n-hexane. The reaction was quenched
after 60 min by adding 20 mL of water. After the reaction
mixture was poured onto 80 mL of water, the layers were
separated and the aqueous layer was extracted with ether. The
combined organic layers and extracts were washed with
saturated NaHCO3 solution, dried over MgSO4, concentrated
in vacuo, and absorbed on Celite. The product was purified
by column chromatography (alumina, 6% water/1:20 ether-
n-pentane) and yielded 1.74 g (87%) of 13a as a yellow solid.
1
13a : Mp 178 °C; H-NMR (300 MHz, CDCl3) δ ) 7.37-7.16
(m; 10H), 4.88-4.86 (m; J ) 2.1 Hz; 2H), 4.61-4.59 (m; J )
2.1Hz; 2H), 2.83 (s; 1H), 2.01-1.79 (m; 10H), 1.66-1.52 (m;
4H), 1.23-1.15 (m;4H), 0.92-0.73 (m; 2H); 13C-NMR (75.4
MHz, CD2Cl2) δ ) 148.1 (C), 127.7 (CH), 127.2 (CH), 126.7
(CH), 108.8 (C), 80.9 (CH), 80.8 (C), 79.8 (CH), 77.3 (C), 31.1
(CH2), 30.5 (CH2), 28.3 (CH2); UV (n-pentane) λmax [nm (log
ꢀ)] ) 376 (2.85), 298 (3.25), 268 (4.43), 220 (4.46), 206 (4.64),
192 (4.87); IR (KBr) 3481, 2915, 2843, 1441, 1325, 810, 756,
701. Anal. Calcd for C32H35CoO (494.20): C, 77.70; H, 7.14.
Found: C, 77.66; H, 7.16.
{(1,2,8,9-η)-Tr icyclo[7.5.0.01.7]t et r a d eca -1,8-d ien e}{η5-
(b i s (p -m e t h y lp h e n y l)h y d r o x y m e t h y l)c y c lo p e n t a -
d ien yl}coba lt (13b). To a dispersion of 34 mg (4.8 mmol) of
lithium in 15 mL of ether was added 831 mg (0.54 mmol) of
p-bromotoluene at -15 °C. After the reaction mixture was
stirred for 30 min, 200 mg (0.54 mmol) of 9, dissolved in 5 mL
of ether, was added dropwise at -15 °C. After being warmed
to 0 °C and stirred for an additional 2 h, the reaction mixture
was poured in 50 mL of ice cold water. The working up
procedure was carried out as decribed for 13a yielding 80 mg
(0.15 mmol) (57%) of 13b as an orange-red solid. 13b: Mp
1
173-175 °C (dec); H-NMR (300 MHz, CDCl3) δ ) 7.25-7.20
(m; 4H), 7.05-7.02 (m; 4H), 4.86 (m; J ) 2.1 Hz; 2H), 4.58 (m;
J ) 2.1; 2H), 2.76 (s; 1H), 2.28 (s; 6H), 2.00-1.80 (m; 12H),
1.64-1.50 (m; 2H), 1.26-1.19 (m; 4H), 0.88-0.75 (m; 2H); 13C-
NMR (75,4 MHz, CD2Cl2) δ ) 144.9 (C), 135.7 (C), 128.0 (CH),
126.7 (CH), 108.7 (C), 80.3 (C), 80.2 (CH), 79.4 (CH), 77.1 (C),
30.7 (CH2), 30.1(CH2); 27.9 (CH2), 20.9(CH3); UV (CHCl3) λmax
[nm (log ꢀ)] ) 244 (4.08), 270 (4.40), 298 (3.36), 350 (2.99); IR
(KBr) 3496, 2919, 2846, 2816, 1509, 1442, 810, 784, 519, 585,
435. Anal. Calcd for C34H39CoO (522.23): C, 78.13; H, 7.53.
Found: C, 78.20; H, 7.51.
1
crystals. 14b: Mp 161 °C (dec); H-NMR (300 MHz, CDCl3,
223 K) δ ) 7.42-7.18 (m; 8H), 6.12 (m; 2H), 5.82 (m; 2H), 2.33
(m; 6H), 2.09-1.36 (m; 14H), 1.16-0.71 (m; 6H); 13C-NMR
(75.4 MHz, CDCl3, 223 K) δ ) 175.32 (C), 145.00 (C), 137.52
(C), 132.76 (CH), 129.89 (CH), 108.39 (C), 101.83 (CH), 97.60
(C), 85.42 (CH), 28.92 (CH2), 28.15(CH2), 27.23 (CH2),
22.06(CH3); UV (CH2Cl2) λmax [nm (log ꢀ)] ) 220 (4.25), 256
(4.21), 380 (4.37), 602 (3.85); IR (KBr) 3432, 2924, 2855, 2361,
1635, 1178, 1083; HRMS (FAB+) calcd for C34H38Co m/ z
505.2305, found m/ z 505.2341.
{(1,2,8,9-η)-Tr icyclo[7.5.0.01.7]t et r a d eca -1,8-d ien e}{η5-
(b is (p -flu o r o p h e n y l)m e t h y liu m )c y c lo p e n t a d ie n y l}-
coba lt Tetr a flu or obor a te (14c). To a solution of 100 mg
(0.17 mmol) of 13c in 5 mL of ether was added 0.2 mL of 54%
tetrafluoroboric acid solution in ether at 0 °C. The working
up procedure was carried out as described for 14a , but no
crystals could be obtained. 14c: 1H-NMR (300 MHz, CDCl3,
{(1,2,8,9-η)-Tr icyclo[7.5.0.01.7]t et r a d eca -1,8-d ien e}{η5-
(b i s (p -fl u o r o p h e n y l )h y d r o x y m e t h y l )c y c l o p e n t a -
d ien yl}coba lt (13c). To a dispersion of 34 mg (4.8 mmol) of
lithium in 15 mL of ether was added 840 mg (0.54 mmol) of
p-bromoflourobenzene at -30 °C. After the reaction mixture
was stirred for 30 min, 200 mg (0.54 mmol) of 9, dissolved in
5 mL of ether, was added dropwise at -30 °C. After being
warmed to 0 °C and stirred for an additional 2 h, the reaction
mixture was poured in 50 mL of ice cold water. The working
up procedure was carried out as described for 13a yielding 232
mg (0.15mmol) (81%) of 13c as a yellow solid. 13c: Mp 133

5640 Organometallics, Vol. 15, No. 26, 1996
Gleiter et al.
223 K) δ ) 7.48-7.09 (m; 8H), 5.98 (m; 2H), 5.89 (m; 2H),
1.92-1.68 (m; 16H), 1.21-0.80 (m; 4H); 13C-NMR (75.4 MHz,
CDCl3, 263 K) δ ) 179.36 (C), 171.22 (C), 168.41 (C); 134.81
(CH), 134.62 (CH), 117.38 (CH), 116.94 (CH), 102.17 (CH),
99.50 (C), 85.33 (CH), 77.19 (C), 28.93 (CH2), 28.26 (CH2), 27.43
(CH2).
unit cell was determined and refined from 31 reflections (3.6
< 2θ < 46.0°).
C
34H38BCoF 4 (14b). A deep violet crystal of the dimensions
0.1 × 0.2 × 0.4 mm3 was obtained from ether/methylene-
chloride at -10 °C. The unit cell was determined and refined
from 39 reflections (2.7 < 2θ < 54°).
X-r a y Cr ysta llogr a p h y a n d Str u ctu r e Solu tion . Data
were collected on a Siemens (Nicolet Syntex) R4m/V diffrac-
tometer, and relevant crystal data and data collection param-
eters are given in Table 4. The structures were solved by
direct methods, least-squares refinement, and Fourier tech-
niques. All calculations were performed with the SHELXTL
PLUS14 and SHELXT-9315 programs.
Ack n ow led gm en t. This paper is dedicated to Pro-
fessor Walter Siebert on the occasion of his 60th
birthday. We are grateful to the Deutsche Forschungs-
gemeinschaft (Grant SFB 247), the Fonds der Chemis-
chen Industrie, and the BASF Aktiengesellschaft for
financial support.
C34H39CoO (13b). A orange-red crystal of the dimensions
0.2 × 0.3 × 0.3 mm3 was obtained from ether at -10 °C. The
Su p p or tin g In for m a tion Ava ila ble: Tables of atom
coordinates and thermal parameters (5 pages). Ordering
information is given on any current masthead page.
(14) SHELXTL PLUS: Sheldrick, G. M. University of Go¨ttingen.
(15) SHELXT 93: Sheldrick, G. M. Program for Crystal Structure
Refinement, University of Go¨ttingen.
OM960694D