Synthesis, characterization and reactivity of iron-olefin complexes of the type [CpFe(CO)2(η2-CH2=CHR)] +X- (Cp = η5-C5 H5; R = CH3 to n-C14H29; X = PF6 or BF4)

Article abstract of DOI:10.1016/j.jorganchem.2003.08.044

A series of iron-olefin complexes of the type [CpFe(CO)₂ (η²-CH₂=CHR)]⁺ (R=CH₃ to n-C₁₄H₂₉) have been prepared using various synthesis methods. In addition, the complexes [Cp*Fe(CO)₂(η²-CH₂= CHR)]⁺ (Cp=η⁵-C₅ (CH₃)_5; R=CH₃, n-C₃ H₇ and n-C₁₄H₂₉) and [CpRu(CO) ₂(η²-CH₂=CHR)]⁺ (R=CH₃, n-C₃H₇ and n-C₁₄ H₂₉) have been synthesized by reacting the iron-alkyl complexes Cp*Fe(CO)₂(CH₂CH₂R) or ruthenium-alkyl complexes CpRu(CO)₂(CH₂CH ₂R) with Ph₃CPF₆. A number of these complexes are new and have been fully characterized by analytical and spectroscopic methods. The reaction of [CpFe(CO)₂ (η²-CH₂=CHR)]⁺ with the isopropoxide ion gave the new ether derivatives [CpFe(CO)₂ (CH₂CH{OCH(CH₃)₂}R)] (R=CH₃, n-C₂H₅, n-C₄H₉ and n-C₁₃H₂₇).

Full text of DOI:10.1016/j.jorganchem.2003.08.044

Journal of Organometallic Chemistry 688 (2003) 181ꢀ191
/
www.elsevier.com/locate/jorganchem
Synthesis, characterization and reactivity of ironꢀ
the type [CpFe(CO)2(h2-CH2ÄCHR)]ꢁXꢂ (Cpꢃ
to n-C14H29; XꢃPF6 or BF4)
/
olefin complexes of
/
/
h5-C5H5; Rꢃ
/
CH3
/
Hadley S. Clayton a, John R. Moss b,*, Mark E. Dry c
a Department of Chemistry, University of South Africa, Pretoria 0003, South Africa
b Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
c Department of Chemical Engineering, University of Cape Town, Rondebosch 7701, South Africa
Received 21 March 2003; accepted 22 August 2003
Abstract
A series of ironꢀ
various synthesis methods. In addition, the complexes [Cp*Fe(CO)2(h2-CH2Ä
n-C14H29) and [CpRu(CO)2(h2-CH2ÄCHR)]ꢁ (Rꢃ
CH3, n-C3H7 and n-C14H29) have been synthesized by reacting the ironꢀ
complexes Cp*Fe(CO)2(CH2CH2R) or rutheniumꢀalkyl complexes CpRu(CO)2(CH2CH2R) with Ph3CPF6. A number of these
complexes are new and have been fully characterized by analytical and spectroscopic methods. The reaction of [CpFe(CO)2(h2-
CHR)]ꢁ with the isopropoxide ion gave the new ether derivatives [CpFe(CO)2(CH2CH{OCH(CH3)2}R)] (Rꢃ
CH3, n-C2H5,
/
olefin complexes of the type [CpFe(CO)2(h2-CH2Ä
/
CHR)]ꢁ (Rꢃ
CHR)]ꢁ (Cp*ꢃ
/
CH3 to n-C14H29) have been prepared using
h5-C5(CH3)5; Rꢃ
CH3, n-C3H7 and
alkyl
/
/
/
/
/
/
/
CH2Ä
/
/
n-C4H9 and n-C13H27).
# 2003 Elsevier B.V. All rights reserved.
Keywords: Iron; Olefin; Cyclopentadienyl; Pentamethylcyclopentadienyl; Ruthenium
1. Introduction
We have investigated the synthesis of the ironꢀ
complexes using a number of different methods (Scheme
1). The complexes [CpFe(CO)2(h2-CH2ÄCHR)]ꢁPF6ꢂ
(RꢃCH3, C2H5, n-C3H5, n-C11H23 to n-C14H29 and n-
C16H33) were prepared by reacting the appropriate
ironꢀalkyl complex with Ph3CPF6. The complexes
[CpFe(CO)2(h2-CH2Ä
n-C6H13) were
/
olefin
While transition metalꢀ
/
olefin complexes of the type
/
[CpFe(CO)2(h2-CH2ÄCHR)]ꢁ (Rꢃ
/
/H, CH3) are well
/
known and the properties and reactivity of these
complexes have been extensively investigated [1], com-
paratively little work has been carried out on the
/
/
CHR)]ꢁBF4ꢂ (Rꢃ
prepared by
/
n-C4H9 and
analogous long chain a-olefin complexes (R]
C4H9). These ironꢀolefin complexes are important
because of their significance as model compounds for
transition metalꢀolefin intermediates in a wide range of
catalytic reactions and their applications in stoichio-
metric organic synthesis [2].
/n-
reacting
[CpFe(CO)2(THF)]ꢁBF4ꢂ with the corresponding a-
/
olefin.
CHR)]ꢁBF4ꢂ (Rꢃ
were prepared by reacting CpFe(CO)2I with the corre-
sponding a-olefin, while the complexes Rꢃn-C9H19
and n-C10H21 were prepared by reacting the isobuteneꢀ
iron complex [CpFe(CO)2(h2-CH2ÄC(CH3)2)]ꢁBF4ꢂ
with 1-undecene and 1-dodecene respectively.
Here we report the synthesis and full characterization
of an extensive series of ironꢀolefin complexes
The
complexes
[CpFe(CO)2(h2-CH2Ä
/
/
/n-C5H11, n-C7H15 and n-C8H17)
/
/
/
* Corresponding author. Tel.: ꢁ
7499.
E-mail address: jrm@science.uct.ac.za (J.R. Moss).
/
27-21-650-2535; fax: ꢁ27-21-689-
/
/
0022-328X/03/$ - see front matter # 2003 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2003.08.044

182
H.S. Clayton et al. / Journal of Organometallic Chemistry 688 (2003) 181ꢀ191
/
Scheme 1. (i) Ph3CPF6/CH2Cl2; (ii) a-olefin/CH2Cl2; (iii) AgBF4/a-olefin/CH2Cl2; (iv) a-olefin/CH2Cl2.
[CpFe(CO)2(h2-CH2Ä
/
CHR)]ꢁXꢂ (Rꢃ
/
CH3 to n-
fin. The preparation of 5, 7 and 8 from the iodo complex
[CpFe(CO)2I] is a two step process: firstly the halide is
eliminated to generate the coordinatively unsaturated
intermediate [CpFe(CO)2]ꢁ which then reacts with the
C14H29; XꢃPF6 or BF4). Furthermore, the reactivity
/
of a few of these complexes with isopropanol, leading to
the elaboration of the olefin is also reported.
olefin to form the ironꢀolefin complex [5]. A side
/
product of this reaction is the known iodine bridged
complex [CpFe(CO)]2IꢁBF4ꢂ which is obtained in ca.
40% yield.
The olefin complexes 9 and 10 were prepared through
a ligand exchange reaction using the thermodynamically
2. Results and discussions
2.1. Synthesis of [CpFe(CO)2(h2-CH2Ä
/
CHR)]ꢁ
The olefin complexes 1ꢀ3 and 11ꢀ14 were synthesized
/
/
unstable ironꢀisobutene complex. As this method is
/
by the reaction of the corresponding alkyl complex
[CpFe(CO)2R] with the trityl salt, Ph3CPF6, in CH2Cl2
according to the method reported by Baird and co-
workers [3]. It is found that the reaction of
[CpFe(CO)2R] with Ph3CPF6 at room temperature is
chain-length dependent. Abstraction of a b-hydride ion
restricted to the preparation of olefin complexes more
stable than the isobutene complex, and as stability
generally decreases with olefin substitution, a-olefins
are particularly well-suited as exchange partners.
The complexes [Cp*Fe(CO)2(h2-CH2Ä
(RꢃCH3, 15; n-C3H7, 16; n-C14H29, 17) and
[CpRu(CO)2(h2-CH2ÄCHR)]ꢁPF6ꢂ (Rꢃ
CH3, 18; n-
/
CHR)]ꢁPF6ꢂ
/
from the short-chain iron-alkyls [CpFe(CO)2R] (Rꢃ
/n-
/
/
C3H7 to n-C5H11) proceeds rapidly at room temperature
and the reaction is complete within 30 min. For the
C3H7, 19; n-C14H29, 20) were synthesized by hydride
abstraction from the b-carbon of the corresponding
long-chain iron-alkyls (Rꢃ/n-C13H27 to n-C16H33) how-
metalꢀ
synthesized by ligand exchange methods because of the
L bond (LꢃTHF, halide, isobutene) in
/
alkyl complexes. These complexes cannot be
ever, the reaction rate is much slower and the reaction
does not go to completion; the longer the polymethylene
chain the longer the reaction time required. The large
steric demand of the Ph3Cꢁ cation could account for
the decrease in the rate of the reaction with the increase
in alkyl chain-length as Slack and Baird [4] have shown
that the reaction proceeds by preferential elimination of
the b-hydride.
stronger MÃ
/
/
these systems due to the increased electron density on
the metal.
The ironꢀ
crystalline solids and the rutheniumꢀ
/
olefin complexes were isolated as yellow
olefin complexes as
/
white crystalline solids after purification by recrystalli-
zation. The iron complexes are very stable at room
temperature for periods of months both in solution and
in the solid state. The ruthenium complexes however are
less stable in solution and decompose after a few days at
Complexes 4 and 6 have been successfully synthesized
in
moderate
yields
by
the
reaction
of
[CpFe(CO)2(THF)]ꢁBF4ꢂ with the corresponding ole-

H.S. Clayton et al. / Journal of Organometallic Chemistry 688 (2003) 181ꢀ
/191
183
ꢂ
/
5 8C in solutions of acetone, dichloromethane and
2.2.2. 1H-NMR spectroscopy
1
acetonitrile.
The H-NMR data for complexes 1ꢀ
/
14 are summar-
ized in Table 4, 15ꢀ
/
17 in Table 5, and 18ꢀ20 in Table 6.
/
The 1H-NMR spectra for the [CpFe(CO)2(h2-CH2Ä
/
CHR)]ꢁ complexes exhibit a sharp singlet at ca. 5.9
ppm (acetone-d6) and 5.5 ppm (acetonitrile-d3) for the
five equivalent Cp protons, which is in good agreement
with the data reported for the shorter chain complexes
2.2. Characterization
The olefin complexes (1ꢀ
acterized. The yields, melting points, IR spectral data as
well as elemental analysis data for the compounds (1ꢀ
20) are summarized in Tables 1ꢀ3. The complexes have
been characterized by satisfactory C and H analysis. The
1H- and 13C-NMR data are reported in Tables 4ꢀ
9. The
/
20) have been fully char-
/
[8,10ꢀ
and 5.8 ppm (acetonitrile-d3) for the analogous ruthe-
nium complexes. The Cp* methyls for 15ꢀ17 give rise to
a singlet at ca. 2.0 ppm (acetone-d6) and 1.9 ppm
(acetonitrile-d3).
Upon coordination to the metal, the protons of the
olefinic carbons become more shielded due to the effect
of back-bonding from the metal, the partial change in
hybridization of the olefinic carbon atoms towards sp3
and the magnetic anisotropy of the aromatic Cp ring.
An upfield shift relative to the free olefin is observed for
the geminal protons of about 1.3 ppm for the trans
/
12]. The Cp peak appears at ca. 6.1 (acetone-d6)
/
/
/
FAB mass spectral data for three of the cationic olefin
complexes are summarized in Table 10.
2.2.1. IR spectroscopy
The IR spectral data for the complexes (1ꢀ
good agreement with the data reported for some known
8] and show two strong n(CO) bands in
/14) are in
compounds [6ꢀ
/
CH2Cl2 solution at ca. 2075 and 2035 cmꢂ1 (Table 1).
There is no significant shift in the n(CO) band positions
upon changing the length of the polymethylene chain or
as the counterion was varied.
proton and
1
ppm for the cis proton in the
CHR)]ꢁ complexes. For the Cp*
[CpFe(CO)2(h2-CH2Ä
/
complexes the upfield shift for the cis proton increased
to 1.8 ppm while the trans proton only shifted about 1.6
ppm relative to the free olefin. This could be an effect of
a greater degree of sp3 character of the olefinic carbons
in the Cp* complexes compared to the Cp complexes as
a result of increased back-bonding from the metal. For
the ruthenium complexes there is an upfield shift of
about 0.9 ppm for the cis proton and 1.0 ppm for the
trans proton relative to the free olefin. There is no
evidence of geminal coupling in either the iron or
ruthenium complexes. Separate resonances are observed
for the two methylene protons a to the double bond. A
distinct multiplet for one of the protons is observed at
The n(CO) values for the Cp* complexes are lower
than that for the analogous Cp complexes by ca. 20
cmꢂ1 (Table 2). This is consistent with the increase in
electron density on the metal in the Cp* complexes
which results in increased back-bonding to the carbonyl
groups, and hence a lower n(CO) [9]. The rutheniumꢀ
olefin complexes exhibit carbonyl bands at 2085 and
2045 cmꢂ1 (Table 3) indicating that the CÃ
O bond is
stronger in the [CpRu(CO)2(h2-CH2ÄCHR)]ꢁ com-
plexes than in the [CpFe(CO)2(h2-CH2ÄCHR)]ꢁ com-
plexes; conversely the RuÃCO bond is weaker than the
FeÃCO bond.
/
/
/
/
/
/
Table 1
Data for [CpFe(CO)2(h2-CH2Ä
/
CHR)]ꢁ
a
Compound
Yield
Dec. point (8C)
IR n(CO) (cmꢂ1
)
Elemental analysis (%)
C found (calc.)
H found (calc.)
1
2
66
72
72
75
38
53
47
30
52
65
76
43
81
60
146
126
121
118
104
101
96
2077, 2039
2078, 2039
2077, 2039
2074, 2032
2072, 2026
2075, 2037
2072, 2034
2073, 2036
2075, 2037
2074, 2035
2076, 2039
2077, 2039
2076, 2039
2075, 2037
32.89 (33.00)
35.16 (34.98)
36.64 (36.78)
45.01 (44.96)
46.16 (46.48)
47.55 (47.94)
48.83 (49.30)
50.48 (50.57)
48.03 (48.27)b
53.13 (52.85)
47.78 (47.66)
48.78 (48.69)
50.37 (49.66)
50.05 (50.59)
3.04 (3.02)
3.48 (3.44)
3.88 (3.83)
5.07 (4.98)
5.18 (5.25)
5.54 (5.59)
5.70 (5.90)
6.30 (6.19)
6.12 (6.08)b
6.79 (6.72)
6.29 (6.15)
6.41 (6.37)
6.51 (6.58)
6.63 (6.78)
3
4
5
6
7
8
96
97
9
10
11
12
13
14
95
103
98
101
107
a
Measured in CH2Cl2.
Calculated with 0.5 mol of CH2Cl2.
b

184
H.S. Clayton et al. / Journal of Organometallic Chemistry 688 (2003) 181ꢀ
/191
Table 2
Data for [Cp*Fe(CO)2(h2-CH2Ä
/
CHR)]ꢁ
Compound
Yield
M.p. (8C)
IR n(CO) (cmꢂ1 a
)
Elemental analysis (%)
C found (calc.)
H found (calc.)
15
16
17
83
92
44
104 dec.
112 dec.
129
2052, 2015
2056, 2016
2056, 2015
41.59 (41.52)
44.33 (44.20)
54.46 (54.58)
4.88 (4.84)
5.47 (5.41)
7.32 (7.63)
127ꢀ
/
a
A measured in CH2Cl2 solution.
about 0.7 ppm from the Ã
/
(CH2)x Ã
/
resonance which
reported. The salts investigated exhibit peaks corre-
sponding to the parent molecular ion (Mꢁ) without its
anionic counterion. All the complexes show similar
fragmentation patterns. The two main fragmentation
obscures the signal from the other proton.
2.2.3. 13C-NMR spectroscopy
pathways are as follows: Mꢁ, Mꢁ ꢂ
olefinꢂ olefinꢂ
CO, Mꢁ ꢂ 2CO (Path A) and Mꢁ,
ꢁ ꢂCO, Mꢁ ꢂ2CO, Mꢁ
2COꢂolefin (Path B).
A peak of low intensity corresponding to the ion
[CpM(CO)2H]ꢁ (Mꢃ
Fe, Ru) was observed in each
/
olefin, Mꢁ ꢂ
/
The 13C-NMR data for complexes 1ꢀ
/
14 are summar-
17 in Table 8, and 18ꢀ20 in Table 9.
The 13C-NMR data for 4ꢀ
6 and the tetrafluoroborate
salts of 1ꢀ3 have been reported by Laycock and Baird
[13] and our results agree well with their reported data.
The [CpFe(CO)2(h2-CH2ÄCHR)]ꢁ complexes give rise
/
/
/
ized in Table 7, 15ꢀ
/
/
M
/
/
ꢂ
/
/
/
/
/
spectrum. The fragmentation pattern observed for these
complexes is similar to that reported for the neutral
CpMn(CO)2(h2-olefin) complexes [14].
/
to a single peak at ca. 90 ppm for the five equivalent
aromatic carbons of the Cp ligand. These signals were
observed at ca. 93 ppm for the Cp* complexes and 103
ppm for the Ru complexes. This variation is due to the
shielding of the carbon atoms by the methyl substituents
on the aromatic ring in the Cp* complexes and the
increased electron density on the metal in the Ru
complexes. These resonances are not affected by the
increase of the polymethylene chain length of the olefin.
The complexes are chiral and two diastereotopic
carbonyl groups give rise to two distinct peaks; about
2 ppm apart for complexes 1ꢀ
17 and 1.5 ppm apart for 18ꢀ
carbonyl carbons are often weak and broad due to the
long relaxation times of these carbon atoms and hence
these peaks were not observed in a few of the spectra.
The carbon atoms of the alkyl substituent exhibit
resonances typical of normal organic hydrocarbons.
2.3. Reactivity of [CpFe(CO)2(h2-CH2Ä
isopropanol
/
CHR)]ꢁ with
The complexes [CpFe(CO)2(h2-CH2Ä
/
CHR)]ꢁ (Rꢃ
/
CH3, n-C2H5, n-C4H9 and n-C13H27) react with
(CH3)2CHOH to form new s-bonded ether complexes
in low yield (Scheme 2). These complexes were isolated
after vacuum sublimation as yellow, exceedingly air-
sensitive oils. No increase in stability was observed as
the length of the alkyl chain increased, however, the
adducts of the longer chain olefins were more difficult to
purify because of their reduced volatility. These new
complexes were fully characterized by IR, 1H-, 13C-
NMR, elemental analysis and mass spectroscopy.
/
14, 0.3 ppm apart for 15ꢀ
/
/20. The signals due to the
2.2.4. Mass spectra
The fast atom bombardment mass spectra for com-
plexes 4, 19 and 20 were recorded (Table 10). No mass
spectral data for complexes of the type [CpM(CO)2(h2-
CHR)]ꢁ (Mꢃ
Fe, Ru) have previously been
/
Scheme 2.
CH2Ä
/
Table 3
Data for [CpRu(CO)2(h2-CH2Ä
/
CHR)]ꢁ
Compound
Yield
M.p. (8C)
IR n(CO) (cmꢂ1 a
)
Elemental analysis (%)
C found (calc.)
H found (calc.)
18
19
20
90
57
71
187 dec.
136
152
2086, 2040
2085, 2042
2085, 2042
29.76 (29.35)
33.03 (32.98)
47.17 (46.72)
2.68 (2.69)
3.56 (3.43)
6.28 (6.26)
134ꢀ
/
150ꢀ
/
a
A measured in CH2Cl2 solution.

H.S. Clayton et al. / Journal of Organometallic Chemistry 688 (2003) 181ꢀ
/191
185
Table 4
1H-NMR data for [CpFe(CO)2(h2-CH2Ä
/
CHR)]ꢁ a
CH2 (cis) 3J(HH) b
Compound Cp CH
Ä
/
Ä
/
Ä
/
CH2 (trans) 3J(HH) b
Ä
/
CHCH
Ã
/
(CH2)x Ã
/
Ã
CH3 3J(HH) b
/
1
5.88 (5H, s) 5.20 (1H, m) 4.06 (1H, d, 8.0)
5.89 (5H, s) 5.33 (1H, m) 4.04 (1H, d, 8.3)
5.89 (5H, s) 5.28 (1H, m) 4.08 (1H, d, 8.3)
5.89 (5H, s) 5.30 (1H, m) 4.06 (1H, d, 8.2)
5.90 (5H, s) 5.31 (1H, m) 4.06 (1H, d, 8.1)
5.87 (5H, s) 5.30 (1H, m) 4.06 (1H, d, 8.3)
5.88 (5H, s) 5.31 (1H, m) 4.06 (1H, d, 8.1)
5.50 (5H, s) 4.97 (1H, m) 3.75 (1H, d, 8.2)
5.52 (5H, s) 4.98 (1H, m) 3.76 (1H, d, 8.3)
5.52 (5H, s) 4.98 (1H, m) 3.77 (1H, d, 8.1)
5.50 (5H, s) 4.95 (1H, m) 3.75 (1H, d, 8.3)
5.52 (5H, s) 4.98 (1H, m) 3.76 (1H, d, 8.3)
5.50 (5H, s) 4.96 (1H, m) 3.75 (1H, d, 8.2)
5.52 (5H, s) 4.96 (1H, m) 3.77 (1H, d, 8.3)
3.68 (1H, d, 14.4)
3.63 (1H, d, 14.7)
3.67 (1H, d, 14.4)
3.61 (1H, d, 14.6)
3.65 (1H, d, 14.5)
3.60 (1H, d, 14.7)
3.62 (1H, d, 14.7)
3.35 (1H, d, 14.6)
3.37 (1H, d, 14.7)
3.37 (1H, d, 14.8)
3.35 (1H, d, 14.7)
3.37 (1H, d, 14.7)
3.35 (1H, d, 14.7)
3.36 (1H, d, 14.5)
1.91 (3H, t, 6.0)
1.18 (3H, t, 7.3)
0.96 (3H, t, 7.0)
0.89 (3H, t, 6.9)
0.87 (3H, t, 6.7)
0.86 (3H, t, 6.3)
2
2.46 (1H, m) 1.70 (1H, m)
2.50 (1H, m) 1.60 (3H, m)
2.50 (1H, m) 1.50 (5H, m)
2.52 (1H, m) 1.50 (7H, m)
2.51 (1H, m) 1.45 (9H, m)
3
4
5
6
7
2.52 (1H, m) 1.45 (11H, m) 0.86 (3H, t, 6.7)
2.37 (1H, m) 1.40 (13H, m) 0.87 (3H, t, 6.7)
2.37 (1H, m) 1.45 (15H, m) 0.89 (3H, t, 6.7)
2.37 (1H, m) 1.45 (17H, m) 0.89 (3H, t, 6.7)
2.35 (1H, m) 1.45 (19H, m) 0.87 (3H, t, 6.8)
2.37 (1H, m) 1.45 (21H, m) 0.89 (3H, t, 6.7)
2.36 (1H, m) 1.45 (23H, m) 0.87 (3H, t, 6.4)
2.38 (1H, m) 1.40 (25H, m) 0.88 (3H, t, 6.2)
8
9
10
11
12
13
14
a
1ꢀ
/
7 measured in acetone-d6; 8ꢀ
/
14 measured in acetonitrile-d3.
b
Coupling constants are given in Hz.
The regiospecificity of the reaction appears to be
[Cp*Fe(CO)2(h2-CH2Ä
C3H7 and n-C14H29) have also been synthesized. All
/
CHR)]ꢁPF6ꢂ (Rꢃ
CH3, n-
/
complete, with only the Markovnikov product being
formed as indicated by the single Cp resonance in the
1H-NMR spectrum. In the IR spectra a shift in the
n(CO) bands is observed from that of a cationic complex
at ca. 2075 and 2035 cmꢂ1 to the expected 2000 and
1940 cmꢂ1 for a neutral complex. A band at 1217 cmꢂ1
these new complexes have been fully characterised. The
most effective method for the synthesis of the ironꢀ
olefin complexes has been found to be via hydride
abstraction from the ironꢀalkyl complexes. The reaction
/
/
conditions are mild and the products can be prepared on
a large scale and in high yield. No side reactions have
was observed which is attributed to the CÃ
/
OÃ
/
C bond.
The 1H-NMR spectra of 21ꢀ
/
24 all show a single peak at
been observed, even with the long chain ironꢀ
complexes.
The complexes [CpFe(CO)2(h2-CH2Ä
/
alkyl
ca. 4.76 ppm. A multiplet at ca. 1.5 ppm for the
diastereotopic FeCH2 methylene group was obtained,
characteristic of a s-bonded alkyl group. Low resolu-
/
CHR)]ꢁ (Rꢃ
/
CH3, n-C2H5, n-C4H9 and n-C13H27) have been shown
to react with isopropanol in the same way as the short-
chain olefin complexes with methanol. The reactivity
pattern displayed is independent of the length of the
alkyl substituent but linked to the basicity and structure
of the nucleophile.
tion mass spectra were obtained for complexes 21ꢀ
Parent molecular ions were observed for all the ironꢀ
ether complexes. The characteristic organic RÃOR?
/
24.
/
/
ether cleavage was observed in each spectrum, however
no peak due to the disassociated ether ligand was
observed.
4. Experimental
3. Conclusion
All reactions were carried out under an atmosphere of
nitrogen using standard Schlenk tube techniques. Re-
agent grade THF, hexane and Et2O were distilled from
sodium/benzophenone; acetone, CH2Cl2 and MeCN
were distilled from anhydrous CaCl2 and isopropanol
was distilled from anhydrous K2CO3 before use. Col-
We have extended the series of known ironꢀolefin
/
complexes
[CpFe(CO)2(h2-CH2Ä
C14H29). The analogous
[CpRu(CO)2(h2-CH2ÄCHR)]ꢁPF6ꢂ
to
include
CHR)]ꢁXꢂ (Rꢃ
new
the
new
complexes
n-C9H19 to n-
complexes
and
/
/
/
Table 5
1H-NMR data for [Cp*Fe(CO)2(h2-CH2Ä
/
CHR)]ꢁPF6ꢂ a
CH2 (cis) 3J(HH) b
Compound C5(CH3)5 CH
Ä
/
Ä
/
Ä
/
CH2 (trans) 3J(HH) b
Ä
/
CHCH
Ã
/
(CH2)x Ã
/
Ã
CH3 3J(HH) b
/
15
16
17
2.01 (15H, s) 4.33 (1H, m) 3.16 (1H, d, 8.2)
2.01 (15H, s) 4.21 (1H, m) 3.35 (1H, d, 8.2)
1.86 (15H, s) 5.30 (1H, m) 2.89 (1H, d, 8.3)
3.43 (1H, d, 14.5)
3.40 (1H, d, 14.4)
3.19 (1H, d, 14.5)
1.80 (3H, t, 6.1)
0.95 (3H, t, 7.1)
2.31 (1H, m) 1.45 (25H, m) 0.89 (3H, t, 6.8)
2.41 (1H, m) 1.45 (3H, m)
a
15, 16 measured in acetone-d6; 17 measured in acetonitrile-d3.
Coupling constants are given in Hz.
b

186
H.S. Clayton et al. / Journal of Organometallic Chemistry 688 (2003) 181ꢀ191
/
Table 6
1H-NMR data for [CpRu(CO)2(h2-CH2Ä
/
CHR)]ꢁPF6ꢂ a
CH2 (cis) 3J(HH)b
Compound Cp
Ä
/
CH
Ä
/
Ä
/
CH2 (trans) 3J(HH)b
Ä
/
CHCH
Ã
/
(CH2)x Ã
/
Ã
CH3 3J(HH) b
/
18
19
20
6.12 (5H, s) 5.47 (1H, m) 4.03 (1H, d, 8.2)
6.14 (5H, s) 4.21 (1H, m) 4.01 (1H, d, 10.4)
5.78 (5H, s) 5.08 (1H, m) 3.78 (1H, d, 8.3)
3.97 (1H, d, 14.0)
3.95 (1H, d, 14.2)
3.69 (1H, d, 14.2)
1.91 (3H, t, 6.0)
1.18 (3H, t, 7.3)
2.30 (1H, m) 1.40 (25H, m) 0.96 (3H, t, 7.0)
2.45 (1H, m) 1.65 (1H, m)
a
18, 19 measured in acetone-d6; 20 measured in acetonitrile-d3.
Coupling constants are given in Hz.
b
umn chromatography was carried out on Merck EM
Reagent neutral ‘‘Alumina oxide 90’’ activity state I,
deactivated by addition of water according to the
manufacturer’s label directions and oven dried at
120 8C. The chemical reagents were obtained from the
methods [15]. The complexes CpFe(CO)2I [16] and
[CpFe(CO)2(THF)]ꢁBF4ꢂ [17] were prepared and pur-
ified by published procedures.
Melting points were recorded on a Kofler hot-stage
microscope (Riechert Thermovar) and are uncorrected.
Microanalyses were performed by the University of
Cape Town Microanalytical Laboratory. Infra red
suppliers shown in parentheses: BF3×
HBF4×Et2O (Merck), Ph3CPF6 (Aldrich), AgBF4
/
Et2O (Merck),
/
spectra were recorded on a PerkinꢀElmer 983 or a
/
(Merck), [CpFe(CO)2]2 (Strem), [Cp*Fe(CO)2]2 (Strem).
The a-olefins were obtained from Aldrich Chemical Co.,
purity shown in parentheses: 1-hexene (99%), 1-heptene
(97%), 1-octene (98%), 1-nonene (98%), 1-decene (94%),
and 1-undecene (95%). All other reagents were obtained
commercially and used without purification unless
otherwise stated.
Paragon 1000 FTIR spectrophotometer in solution cells
1
using NaCl windows. H-NMR spectra were recorded
on a Varian XR 200 (at 200 MHz) spectrometer or a
Varian Unity 400 (at 400 MHz) spectrometer. 13C-NMR
spectra were recorded on a Varian XR 200 (at 50 MHz)
spectrometer or a Varian Unity 400 (at 100 MHz)
spectrometer. Low resolution mass spectra were re-
corded with a VG Micromass 16F spectrometer operat-
ing at 70 eV ionizing voltage.
Compounds of the type [LM(CO)2(R)] (Lꢃ
/
h5-C5H5,
h5-C5(CH3)5; Rꢃ
n-C16H33) were prepared according to the literature
/n-C3H7 to n-C6H13 and n-C13H27 to
Table 7
13C-NMR data for [CpFe(CO)2(h2-CH2Ä
/
CHR)]ꢁ a
CH CH2 Other
b
Compound CO
Cp
Ä
/
Ä
/
1
2
3
4
5
6
7
8
211.41; 209.28
211.41; 209.30
89.99 85.88 55.96 21.69 (CH3)
90.23 91.00 54.38 e(C3); 17.08 (CH3)
89.34 88.21 54.31 38.24(C3); 25.60(C4); 12.08 (CH3)
c
c
c
90.94 90.20 55.83 37.59(C3); 36.14(C4); 23.46(C5); 14.67 (CH3)
89.31 88.54 54.19 36.29(C3); 32.23(C4); 31.01(C5); 22.10(C6); 13.27 (CH3)
e
90.95 90.16 55.82 37.91(C3); 34.03(C4); 32.89(C5); (C6); 23.81(C7); 14.91 (CH3)
212.19; 210.06
210.67; 208.52
211.85; 209.15
e
e
89.44 88.50 54.24 36.36(C3); 32.56(C4); 31.55(C5); (C6); (C7); 22.34(C8); 13.42 (CH3)
89.95 89.79 54.93 37.19 (C3); 33.28(C4); 32.63(C5); 30.21(C6); 29.98(C7); 29.98(C8); 23.38(C9); 14.37
(CH3)
9
10
11
12
13
14
211.17; 209.02
211.22; 209.09
211.20; 209.06
211.21; 209.06
c
89.87 89.51 54.78 37.08 (C3); 33.22(C4); 32.51(C5); 30.09(C6); d(C7); 29.90(C8); 29.59(C9); 23.30(C10);
14.29 (CH3)
89.94 89.55 54.85 37.15 (C3); 33.27(C4); 32.61(C5); 30.26(C6); 30.19(C7); 30.01(C8); 29.96(C9);
29.66(C10); 23.37(C11); 14.36 (CH3)
89.94 89.74 54.90 37.18 (C3); 33.29(C4); 32.64(C5); 30.32(C6); d(C7); 30.20(C8); 30.05(C9); 29.98(C10);
29.68(C11); 23.39(C12); 14.29 (CH3)
89.91 89.57 54.84 37.15 (C3); 33.29(C4); 32.62(C5); 30.34(C6); 30.32(C7); 30.29(C8); 30.18(C9); 30.05(C10);
29.96(C11); 29.66(C12); 23.37(C13); 14.35 (CH3)
89.93 89.68 54.88 37.17 (C3); 33.29(C4); 32.63(C5); 30.35(C6); 30.30(C7); d(C8); d(C9); 30.19(C10);
30.06(C11); 29.97(C12); 29.67(C13); 23.38(C14); 14.37 (CH3)
211.19; 209.07
89.94 89.57 54.87 37.16 (C3); 34.44(C4); 33.29(C5); 32.63(C6); 30.35(C7); 30.19(C8); 30.06(C9); d(C10);
d(C11);d(C12); 29.83(C13); 29.68(C14); 23.37(C15); 14.38 (CH3)
a
b
c
1ꢀ
/
7 measured in acetone-d6; 8ꢀ14 measured in acetonitrile-d3.
/
C3 to Cn refer to the C atoms of the alkyl substituent on the alkene.
Peak not observed.
Peaks overlap.
Peak obscured by solvent.
d
e

H.S. Clayton et al. / Journal of Organometallic Chemistry 688 (2003) 181ꢀ
/191
187
Table 8
13C-NMR data for [Cp*Fe(CO)2(h2-CH2Ä
/
CHR)]ꢁ a
CH
b
Compound CO
C5(CH3)5
Ä
/
ÄCH2 C5(CH3)5 Other
/
c
15
103.28
103.34
102.52
101.42
89.34
88.93
60.78 9.93
59.85 9.89
58.88 9.41
22.36 (CH3)
39.82(C3); 27.28(C4); 14.43(CH3)
37.05 (C3); 33.47(C4); 32.56(C5); 30.27(C6); d(C7); d(C8); d(C9);
16
17
214.20; 213.94
213.10; 213.40
30.22(C10); 30.12(C11); 29.99(C12); 29.92(C13); 29.68(C14); 23.31(C15);
14.31 (CH3)
a
b
c
15, 16 measured in acetone-d6; 17 measured in acetonitrile-d3.
C3 to Cn refer to the C atoms of the alkyl substituent on the alkene.
Peak not observed.
d
Peaks overlap.
Table 9
13C-NMR data for [CpRu(CO)2(h2-CH2Ä
/
CHR)]ꢁ a
CH CH2 Other
92.86 83.86 53.75 23.28 (CH3)
b
Compound CO
Cp
Ä
/
Ä
/
18
19
20
197.35; 196.00
197.47; 195.81
196.72; 195.02
92.90 87.05 52.70 40.37(C3); 27.34(C4); 14.25 (CH3)
92.07 86.96 51.70 37.81 (C3); 33.54(C4); 32.63(C5); 30.39(C6); 30.37(C7); 30.35(C8); 30.31(C9); c(C10); c(C11);
30.06(C12); 29.99(C13); 29.59(C14); 23.39(C15); 14.37 (CH3)
a
b
c
18, 19 measured in acetone-d6; 20 measured in acetonitrile-d3.
C3 to Cn refer to the C atoms of the alkyl substituent on the alkene.
Peak obscured by solvent.
Table 10
Mass spectral data for [CpM(CO)2(h2-CH2Ä
Ru; XꢃBF4, PF6)
/
CHR)]ꢁXꢂ (Mꢃ
Fe,
/
microcrystals of 1 (0.21 g, 66%). Spectral data and
analysis of 1 (and others 2ꢀ20) are reported in Section 2.
/
/
Possible assignments
Relative peak intensities (%)
4
19
20
4.2. Preparation of [CpFe(CO)2(h2-CH2Ä
/
Parent, M
100
11
5
100
11
10
51
8
100
7
CHCH2CH3)]ꢁPF6ꢂ, 2
Mꢂ
Mꢂ
Mꢂ
Mꢂ
Mꢂ
Mꢂ
/
CO
/
2CO
2
/
olefin
92
8
54
0
This was prepared by the method described above for
with the following quantities of reagents:
/
COꢂ
2COꢂ
olefinꢁ
/
olefin
1
/
/olefin
10
15
7
30
0
15
CpFe(CO)2(n-C4H9) (0.16 g, 0.69 mmol), Ph3CPF6
(0.30 g, 0.77 mmol), and a reaction time of 30 min at
r.t. Work-up as described for 1 above gave 2 as pale
yellow microcrystals (0.19 g, 72%).
/
/H
4.1. Preparation of [CpFe(CO)2(h2-CH2Ä
CHCH3)]ꢁPF6ꢂ (1)
/
4.3. Preparation of [CpFe(CO)2(h2-CH2Ä
/
CH(CH2)2CH3)]ꢁPF6ꢂ (3)
A solution of CpFe(CO)2(n-C3H7) (0.19 g, 0.88
mmol) in CH2Cl2 (10 ml) was cooled to 0 8C and treated
with a solution of Ph3CPF6 (0.39 g, 1.00 mmol) in
CH2Cl2 (5 ml) over 5 min. The solution turned dark
green. The solution was allowed to warm to room
temperature (r.t.) and the reaction continued for a
further 20 min. The solution was concentrated and
ether added until precipitation of the salt was complete.
The yellow precipitate was collected, washed with ether
and recrystallized from acetone/ether to give pale yellow
This was prepared by the method described above for
with the following quantities of reagents:
1
CpFe(CO)2(n-C5H11) (0.51 g, 2.05 mmol), Ph3CPF6
(0.97 g, 2.05 mmol), and a reaction time of 30 min at
r.t. The solution was concentrated and ether added until
precipitation of the salt was complete. The yellow
precipitate was collected, washed with ether and recrys-
tallized from acetoneꢀ/CH2Cl2/ether to give pale yellow
microcrystals 3 (0.58 g, 72%).

188
H.S. Clayton et al. / Journal of Organometallic Chemistry 688 (2003) 181ꢀ191
/
4.4. Preparation of [CpFe(CO)2(h2-CH2Ä
/
4.8. Preparation of [CpFe(CO)2(h2-CH2Ä
/
CH(CH2)3CH3)]ꢁBF4ꢂ (4)
CH(CH2)7CH3)]ꢁBF4ꢂ (8)
To a solution of [CpFe(CO)2(THF)]ꢁBF4ꢂ (0.78 g,
2.32 mmol) in CH2Cl2 was added 1-hexene (0.85 ml,
6.94 mmol). The reaction was allowed to proceed for 30
This was prepared by the method described above for
5 with the following quantities of reagents: CpFe(CO)2I
(0.50 g, 1.64 mmol), 1-decene (0.30 ml, 1.58 mmol),
AgBF4 (0.36 g, 0.82 mmol) and a reaction time of 18 h at
r.t. Work-up as described for 5 above gave 7 as pale
yellow needle-like crystals (0.19 g, 30%).
min and was then treated with BF3×/Et2O (0.5 ml, 0.05
mmol) and stirred for a further 1 h at r.t. The solution
was filtered, the solvent removed under reduced pressure
and the residue dissolved in a minimum of CH2Cl2.
Addition of ether to the solution gave a yellow
4.9. Preparation of [CpFe(CO)2(h2-CH2Ä
CH(CH2)8CH3)]ꢁBF4ꢂ (9)
/
precipitate which was recrystallized from CH2Cl2ꢀ
/
ether
to give fine, yellow microcrystals of 4 (0.60 g, 75%).
A
solution
of
[CpFe(CO)2(h2-CH2Ä
/
CH(CH3)2]ꢁBF4ꢂ (0.25 g, 0.78 mmol) in CH2Cl2 (20
ml) was combined with 1-undecene (0.30 ml, 1.46 mmol)
and stirred under reflux for 3.5 h. The solution was
allowed to cool to r.t. and then filtered. The filtrate was
concentrated under reduced pressure and cooled to
4.5. Preparation of [CpFe(CO)2(h2-CH2Ä
/
CH(CH2)4CH3)]ꢁBF4ꢂ (5)
A solution of CpFe(CO)2I (0.50 g, 1.64 mmol) in
CH2Cl2 (10 ml) was treated with AgBF4 (0.35 g, 1.80
mmol). After 1 h the solution was filtered under N2
through Celite. To the filtrate was added 1-heptene (0.60
ml, 1.88 mmol) and the solution stirred for 30 min. The
solvent was reduced under vacuum and ether added.
ꢂ
/
20 8C. Ether was added to precipitate a waxy
yellowꢀbrown solid which was recrystallized from
CH2Cl2ꢀether at 4 8C to give fine, yellow microcrystals
of 9 (0.17 g, 52%).
/
/
This solution was cooled overnight at ꢂ15 8C. The
black precipitate that formed was collected, the filtrate
concentrated and ether added to give a yellow precipi-
/
4.10. Preparation of [CpFe(CO)2(h2-CH2Ä
CH(CH2)9CH3)]ꢁBF4ꢂ (10)
/
tate. This product was recrystallized from CH2Cl2ꢀether
/
to yield yellow microcrystals of 5 (0.23 g, 38%). The
black precipitate was identified as [CpFe(CO)2]2IꢁBF4ꢂ
This was prepared by the method described above for
with the following quantities of reagents:
9
(0.17 g, 37%) [5] m.p. 150ꢀ
/
152 8C dec.; IR (CH2Cl2)
[CpFe(CO)2(h2-CH2ÄCH(CH3)2)]ꢁBF4ꢂ (0.17 g, 0.52
/
n(CO) 2063, 2051, 2015 cmꢂ1
;
1H-NMR (CDCl3) d
mmol), 1-dodecene (0.21 ml, 0.95 mmol), and a reaction
time of 2 h under refluxing conditions. Work-up as
described for 9 above gave 10 as pale yellow micro-
crystals (0.15 g, 65%).
(ppm) 5.38 (10H, s, Cp); 13C{H}-NMR (CDCl3) d
(ppm) 85.63 (Cp).
4.6. Preparation of [CpFe(CO)2(h2-CH2Ä
/
4.11. Preparation of [CpFe(CO)2(h2-CH2Ä
/
CH(CH2)5CH3)]ꢁBF4ꢂ (6)
CH(CH2)10CH3)]ꢁPF6ꢂ (11)
This was prepared by the method described above for
with the following quantities of reagents:
This was prepared by the method described above for
with the following quantities of reagents:
CpFe(CO)2(n-C13H27) (0.33 g, 0.92 mmol), Ph3CPF6
(0.40 g, 1.02 mmol), and a reaction time of 1 h at r.t.
Work-up as described for 1 above gave 11 as yellow
microcrystals (0.35 g, 76%).
4
1
[CpFe(CO)2(THF)]ꢁBF4ꢂ (0.27 g, 0.81 mmol), BF3×
/
Et2O (0.1 ml, 0.01 mmol), and a reaction time of 1.5 h
at r.t. Work-up as described for 4 above gave 6 as pale
yellow microcrystals (0.16 g, 53%).
4.7. Preparation of [CpFe(CO)2(h2-CH2Ä
/
4.12. Preparation of [CpFe(CO)2(h2-CH2Ä
/
CH(CH2)6CH3)]ꢁBF4ꢂ (7)
CH(CH2)11CH3)]ꢁPF6ꢂ (12)
This was prepared by the method described above for
5 with the following quantities of reagents: CpFe(CO)2I
(0.20 g, 0.64 mmol), 1-nonene (0.33 ml, 1.88 mmol),
AgBF4 (0.16 g, 0.82 mmol) and a reaction time of 1.5 h
at r.t. Work-up as described for 5 above gave 7 as pale
yellow needle-like crystals (0.12 g, 47%).
This was prepared by the method described above for
with the following quantities of reagents:
CpFe(CO)2(n-C14H29) (1.22 g, 3.35 mmol), Ph3CPF6
(1.33 g, 3.35 mmol), and a reaction time of 20 h at r.t.
Work-up as described for 1 above gave 12 as yellow
microcrystals (0.73 g, 43%).
1

H.S. Clayton et al. / Journal of Organometallic Chemistry 688 (2003) 181ꢀ
/191
189
4.13. Preparation of [CpFe(CO)2(h2-CH2Ä
/
4.16. Preparation of [Cp*Fe(CO)2(h2-CH2Ä
CH(CH2)2CH3)]ꢁPF6ꢂ (16)
/
CH(CH2)12CH3)]ꢁPF6ꢂ (13)
This was prepared by the method described above for
with the following quantities of reagents:
This was prepared by the method described above for
with the following quantities of reagents:
1
1
CpFe(CO)2(n-C15H31) (0.66 g, 1.71 mmol), Ph3CPF6
(0.71 g, 1.83 mmol), and a reaction time of 2 h at r.t.
Work-up as described for 1 above gave 13 as yellow
microcrystals (0.73 g, 81%).
Cp*Fe(CO)2(n-C5H11) (0.47 g, 1.48 mmol), Ph3CPF6
(0.58 g, 1.50 mmol), and a reaction time of 30 min at r.t.
Work-up as described for 1 above gave 16 as yellow
microcrystals (0.63 g, 92%).
4.14. Preparation of [CpFe(CO)2(h2-CH2Ä
/
4.17. Preparation of [Cp*Fe(CO)2(h2-CH2Ä
/
CH(CH2)13CH3)]ꢁPF6ꢂ (14)
CH(CH2)13CH3)]ꢁPF6ꢂ (17)
This was prepared by the method described above for
with the following quantities of reagents:
This was prepared by the method described above for
with the following quantities of reagents:
1
1
CpFe(CO)2(n-C16H33) (0.50 g, 1.28 mmol), Ph3CPF6
(0.60 g, 1.54 mmol), and a reaction time of 2.5 h at r.t.
Work-up as described for 1 above gave 14 as yellow
microcrystals (0.41 g, 60%).
Cp*Fe(CO)2(n-C16H33) (0.32 g, 0.68 mmol), Ph3CPF6
(0.31 g, 0.80 mmol), and a reaction time of 1.5 h at r.t.
Work-up as described for 1 above gave 17 as yellow
microcrystals (0.18 g, 44%).
4.15. Preparation of [Cp*Fe(CO)2(h2-CH2Ä
/
4.18. Preparation of [CpRu(CO)2(h2-CH2Ä
/
CHCH3)]ꢁPF6ꢂ (15)
CHCH3)]ꢁPF6ꢂ (18)
This was prepared by the method described above for
with the following quantities of reagents:
This was prepared by the method described above for
with the following quantities of reagents:
1
1
CpRu(CO)2(n-C3H7) (0.13 g, 0.50 mmol), Ph3CPF6
(0.21 g, 0.55 mmol), and a reaction time of 2.8 h at r.t.
Cp*Fe(CO)2(n-C3H7) (0.13 g, 0.43 mmol), Ph3CPF6
(0.19 g, 0.51 mmol), and a reaction time of 10 min at r.t.
Work-up as described for 1 above gave 15 as yellow
microcrystals (0.16 g, 83%).
Recrystallization from acetoneꢀ
/
ether gave 18 as white
microcrystals (0.18 g, 90%).
Table 11
Data for [CpFe(CO)2(CH2CH{OCH(CH3)2}R)]
Compound
Yield (%)
M.p. (8C)
IR n(CO) (cmꢂ1 a
)
Elemental analysis (%)
C found (calc.)
56.5 (56.2)
H found (calc.)
6.47 (6.47)
21
22
23
24
18
15
23
7
Oil
Oil
Oil
Oil
2002, 1942
2004, 1945
2004, 1944
2002, 1944
59.8 (60.0)
7.41 (7.50)
a
A measured in CH2Cl2 solution.
Table 12
1H NMR data for [CpFe(CO)2(CH2CH{OCH(CH3)2}R)]ꢁ in CDCl3 relative to TMS
Compound
Cp
FeCH2
CH2Ã/CH
OCH
CH(CH3)2
Ã
/
(CH2)x Ã
/
ÃCH3
/
21
22
23
24
4.75 (5H, s)
4.76 (5H, s)
4.76 (5H, s)
4.76 (5H, s)
1.41 (2H, m)
1.47 (2H, m)
1.51 (2H, m)
1.52 (2H, m)
3.41 (1H, m)
3.18 (1H, m)
3.23 (1H, m)
3.23 (1H, m)
3.64 (1H, m)
3.63 (1H, m)
3.64 (1H, m)
3.63 (1H, m)
1.17 (3H, d); 1.13 (3H, d)
1.14 (3H, d); 1.12 (3H, d)
1.15 (3H, d); 1.12 (3H, d)
1.15 (3H, d); 1.12 (3H, d)
1.14 (3H, d)
0.89 (3H, t)
0.89 (3H, t)
0.88 (3H, t)
1.58 (2H, m)
1.31 (6H, m)
1.25 (24H, bs)

190
H.S. Clayton et al. / Journal of Organometallic Chemistry 688 (2003) 181ꢀ191
/
Table 13
13C{H}-NMR data for [CpFe(CO)2(CH2CH{OCH(CH3)2}R)] in CDCl3 relative to TMS
Compound
CO
Cp
FeCH2
CH2Ã/CH
OCH
CH(CH3)2
Ã
/
(CH2)x Ã
/
ÃCH3
/
21
22
23
24
217.6
217.6
217.6
217.6
85.3
85.3
85.3
85.3
9.1
5.9
6.5
6.5
77.9
83.4
82.3
82.3
68.1
68.3
68.2
68.2
23.3; 23.5
22.7; 23.1
22.8; 23.1
22.8; 23.1
22.4
9.9
29.1
36.4; 28.8; 23.0
25.8ꢀ36.7
14.2
14.1
/
Table 14
Mass spectral data for [CpFe(CO)2(CH2CH{OCH(CH3)2}R)]
Possible assignments
Relative peak intensities (%)
21 RꢃCH3 22 Rꢃ
/
/
C2H5
23 Rꢃ/n-C4H9
24 Rꢃn-C13H27
/
Parent, M
9
6
5
4
32
8
28
0
Mꢂ
Mꢂ
Mꢂ
CpFeCH2R
CpFe(CO)2OCH(CH3)2
/CO
/2CO
71
100
52
0
19
6
100
43
26
2
100
41
0
/2COꢂCH(CH3)2
/
100
19
14
4.19. Preparation of [CpRu(CO)2(h2-CH2Ä
CH(CH2)2CH3)]ꢁPF6ꢂ (19)
/
4.22. Reaction of [CpFe(CO)2(h2-CH2Ä
CHCH2CH3)]ꢁPF6ꢂ with isopropanol (22)
/
This was prepared by the method described above for
with the following quantities of reagents:
A suspension of 2 (0.38 g, 1.00 mmol) in CH3CN (10
ml) and isopropanol (10 ml) was treated with Na2CO3
(0.12 g, 1.12 mmol). The solution was stirred for 16 h at
r.t. and monitored by IR. The solvent was removed
1
CpRu(CO)2(n-C5H11) (0.65 g, 2.52 mmol), Ph3CPF6
(1.00 g, 2.57 mmol), and a reaction time of 14 h at r.t.
Recrystallization from acetoneꢀ/dichloromethane (1:4,
under reduced pressure to give a redꢀbrown gum.
/
v/v)/ether gave 19 as white microcrystals (0.63 g, 92%).
Sublimation of the residue at 40 8C/0.05 mmHg gave
(22),
CpFe(CO)2(h1-CH2CH{OCH(CH3)2}CH2CH3)
(0.044 g, 15%) as a bright yellow oil.
4.20. Preparation of [CpRu(CO)2(h2-CH2Ä
/
CH(CH2)13CH3)]ꢁPF6ꢂ (20)
4.23. Reaction of [CpFe(CO)2(h2-CH2Ä
CH(CH2)3CH3)]ꢁPF6ꢂ with isopropanol (23)
/
This was prepared by the method described above for
with the following quantities of reagents:
1
CpRu(CO)2(n-C16H33) (0.15 g, 0.33 mmol), Ph3CPF6
(0.18 g, 0.46 mmol), and a reaction time of 2 h at r.t.
Recrystallization from CH2Cl2/ether gave 20 as white
microcrystals (0.14 g, 71%).
A suspension of 4 (0.15 g, 0.37 mmol) in CH3CN (5
ml) and isopropanol (10 ml) was treated with Na2CO3
(0.04 g, 0.41 mmol). The solution was stirred for 22 h at
r.t. and monitored by IR. The solvent was removed
under reduced pressure to give a redꢀbrown gum.
/
4.21. Reaction of [CpFe(CO)2(h2-CH2Ä
/
Sublimation of the residue at 25 8C/0.05 mmHg gave
CpFe(CO)2(h1-CH2CH{OCH(CH3)2}(CH2)3CH3) (23),
(0.027 g, 23%) as a bright yellow oil.
CHCH3)]ꢁPF6ꢂ with isopropanol, to give 21
A suspension of 1 (0.10 g, 0.28 mmol) in isopropanol
(10 ml) was treated with Na2CO3 (0.04 g, 0.34 mmol).
The solution was stirred for 2 days at r.t. The reaction
was monitored by IR. A colour change from yellow to
4.24. Reaction of [CpFe(CO)2(h2-CH2Ä
/
CH(CH2)12CH3)]ꢁPF6ꢂ with isopropanol (24)
orangeꢀ
/
brown was observed. The solvent was removed
A suspension of 13 (0.20 g, 0.38 mmol) in CH2Cl2 (10
ml) and isopropanol (10 ml) was treated with Na2CO3
(0.05 g, 0.50 mmol). The solution was stirred for 18 h at
r.t. and monitored by IR. The solvent was removed
under reduced pressure to give a redꢀ
/brown gum.
Sublimation of the residue at 40 8C/0.1 mmHg gave
CpFe(CO)2(h1-CH2CH{OCH(CH3)2}CH3) (21), (0.014
g, 18%) as a bright yellow oil. Spectral data and analysis
under reduced pressure to give a orangeꢀ
/
red oil.
of 21ꢀ
/
24 are reported in Tables 11ꢀ14.
/
Sublimation of the residue at 30 8C/0.05 mmHg gave

H.S. Clayton et al. / Journal of Organometallic Chemistry 688 (2003) 181ꢀ
/191
191
CpFe(CO)2(h1-CH2CH{OCH(CH3)2}(CH2)12CH3), 24,
(0.012 g, 7%) as a bright yellow oil.
(e) A. Sanders, C.V. Magatti, W.P. Giering, J. Am. Chem. Soc. 96
(1974) 1610;
(f) A. Rosan, M. Rosenblum, J. Org. Chem. 40 (1975) 3621.
[2] S.G. Davies, Organotransition Metal Chemistry: Applications to
Organic Synthesis, Pergamon Press, Oxford, 1982.
[3] D.E. Laycock, M.C. Baird, J. Org. Chem. 45 (1980) 291.
[4] D. Slack, M.C. Baird, J. Chem. Soc. Chem. Commun. (1974) 701.
[5] B.M. Mattson, W.A.G. Graham, Inorg. Chem. 20 (1981) 604.
[6] D.L. Reger, C.J. Coleman, P.J. McElligott, J. Organomet. Chem.
171 (1979) 73.
Acknowledgements
We thank the University of Cape Town and the
National Research Foundation (NRF) for support,
Johnson Matthey for the loan of ruthenium trichloride,
and Siyabonga Ngubane for help with the final manu-
script.
[7] M.L.H. Green, P.L.I. Nagy, J. Organomet. Chem. 1 (1963) 189.
[8] J.W. Faller, B.V. Johnson, J. Organomet. Chem. 88 (1975) 101.
[9] H.B. Friedrich, P.A. Makhesha, J.R. Moss, B.K. Williamson, J.
Organomet. Chem. 384 (1990) 325.
[10] W.P. Giering, M. Rosenblum, J. Organomet. Chem. 25 (1970)
C71.
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