New, simple synthetic route to functional mono-and biferrocenes

Article abstract of DOI:10.1021/ic902332q

Visible-light photolysis using a simple 100 W lamp of the readily available precursors [(η ⁵-C₅H₄R)Fe(η ⁶-toluene)]-[PF₆] (R = H, Me, Cl, COMe, CO₂H, CO₂Me, CO₂CH₂CCH, CONHCH₂Ph, NHCH₂Ph), or the bimetallic precursor [(μ ₂, η ⁵, η '₅-Fv)Fe₂(η ⁶-toluene) ₂][PF₆]₂ (Fv = fulvalene) in the presence of a substituted cyclopentadienyl salt C₅H₄R0M (R0 = COCH ₃, CO₂ CH₃, PPh₂, SiMe ₂CH₂Cl; M = Li or Na) or the dicyclopentadienyl salt 1, 4-C₆H₄-(CH₂C₅H₄) ₂Na₂ in dichloromethane, acetonitrile, or tetrahydrofuran under ambient conditions selectively yields 15 functional mono-and biferrocenes.

Full text of DOI:10.1021/ic902332q

Inorg. Chem. 2010, 49, 1913–1920 1913
DOI: 10.1021/ic902332q
New, Simple Synthetic Route to Functional Mono- and Biferrocenes
Abdou Khadri Diallo, Jaime Ruiz, and Didier Astruc*
ꢀ
ꢀ
Institut des Sciences Moleculaires, UMR CNRS N° 5255, Universite Bordeaux 1, 33405 Talence Cedex, France
Received November 25, 2009
Visible-light photolysis using a simple 100 W lamp of the readily available precursors [(η5-C5H4R)Fe(η6-toluene)]-
[PF6] (R = H, Me, Cl, COMe, CO2H, CO2Me, CO2CH2CCH, CONHCH2Ph, NHCH2Ph), or the bimetallic precursor
[(μ2,η5,η05-Fv)Fe2(η6-toluene)2][PF6]2 (Fv = fulvalene) in the presence of a substituted cyclopentadienyl salt
C5H4R0M (R0 = COCH3, CO2CH3, PPh2, SiMe2CH2Cl; M = Li or Na) or the dicyclopentadienyl salt 1,4-C6H4-
(CH2C5H4)2Na2 in dichloromethane, acetonitrile, or tetrahydrofuran under ambient conditions selectively yields 15
functional mono- and biferrocenes.
Introduction
scaffold, catalysis,12 liquid crystals,13 non-linear optical mate-
rials,14 magnetic materials,15 self-assembled monolayers,16
polymers,17 and dendrimers.18 Common syntheses4c,19 involve
the reactions of substituted cyclopentadienyl derivatives of
main-group metals (such as C5Me5Li)20 with FeCl2 that
yield symmetrically di- or polysubstituted ferrocenes and the
Friedel-Crafts reactions pioneered by Woodward2 leading to
mono- and symmetrically disubstituted ferrocenes. This
latter reaction is especially useful to produce mono- and
1,10-diacylferrocenes, although further chromatographic se-
paration is required. Finally, the third well-known type of
synthesis involves metalation of ferrocene with n-butyl-lithium
followed by electrophilic reaction that also leads to mixtures of
mono- and 1,10disubstituted ferrocenes to some extent often
requiring further chromatographic separation.19
Ferrocene syntheses have been continuously pursued since
1952, when the sandwich structure was disclosed,1 because of
the aromaticity2 and robustness3 of the sandwich frame and
because of their numerous applications.4 Ferrocene deriva-
tives have indeed been used in many areas including oncol-
ogy5 and other biomedical applications,6 electrochemistry,7
redox biosensors,8 reagents and standards,9 mediators of
enzyme reactions,10 resins, fuel additives, paints,11 ligand
*To whom correspondence should be addressed. E-mail: d.astruc@
ism.u-bordeaux1.fr.
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r
2010 American Chemical Society
Published on Web 01/22/2010
pubs.acs.org/IC

1914 Inorganic Chemistry, Vol. 49, No. 4, 2010
Diallo et al.
Table 1. Syntheses of Ferrocene and Biferrocene Derivatives by Visible-Light Photolysis Reactions of [CpFe(η6-toluene)[PF6] with Functional Cyclopentadienyls As
Sodium Salts [except for R0 = PPh2 (7, entry 2) and SiMe2CH2Cl (8 and 10, entries 3 and 6) with Lithium Salts]
entry
[Fe(η5-C5H4R)(η5-C5H4R0)]
R
R0
yield (%)
1
2
3
4
5
6
7
8
6a
H
H
CO2Me
PPh2
SiMe2CH2Cl
CO2Me
COMe
98
51
80
95
88
75
15
85
70
90
98
44
27
87
86
18
7a
8b
H
COMe
CO2Me
COMe
CO2H
CO2CH2CtCH
CONHCH2Ph
Cl
Me
NHCH2Ph
Me
9a
9a
10b
11a
12a
13a
14a
15a
16a
SiMe2CH2Cl
COMe
CO2Me
CO2Me
CO2Me
CO2Me
CO2Me
CO2Me
CO2Me
COMe
9
10
11
12
13
14
15
16
17a [Fe(η5-C5R5)(η5-C5H4R0)]
18a [Fe2(η5-C5H4R0)2(μ2-η5,η0 -Fv)]
5
19a [Fe2(η5-C5H4R0)2(μ2-η5, η0 -Fv)]
5
20c 1,4-C6H4(FcCH2)2
a In MeCN. b In dichloromethane. c In THF, 20, entry 16: Fv = fulvalene (C5H4-C5H4), Fc = ferrocenyl (C10H9).
that has so far not been exploited except in a few exceptional
cases with C5Me5 (Cp*). Indeed [Cp*Fe(NCMe)3][PF6]21 and
[Cp*Fe(acac)]22 (acac = acetylacetonate) are known stable
(although air-sensitive) complexes, and they have been used to
synthesize 1,2,3,4,5-pentamethylferrocene23 and piano-stool-
shape complexes.24 The complex [Cp*Fe(NCMe)3][PF6] has
recently been used to also further introduce C5H4R ligands
with long functional R arms to link pentamethylferrocene
moieties to gold nanoparticles and dendrimers.25 The dimers
[(η5-C5R5)Fe(CO)2]2 (R=H or Me) have also been used in
rare occasions as C5R5Fe sources to introduce special penta-
hapto ligands such as phospholes26 and C60 derivatives at high
temperatures, but the method cannot be generalized to func-
tional cyclopentadienyls.27 Also note that [CpFe(NCMe)3]-
[PF6] (Cp = η5-C5H5) is not stable above -40 °C and can thus
only be a short-lived intermediate under ambient conditions.28
Likewise, [CpFe(acac)] is unknown.
cursors of the intermediate 12-electron fragments (η5-C5H4R)-
Feþ or their weakly solvated forms in ferrocene syntheses.
These complexes are easily accessible in large scales by reac-
tions of ferrocenes with arenes in the presence of aluminum
chloride. They are are robust, being stable thermally up to
above 200 °C. The parent complex [CpFe(η6-C6H6)][PF6]
and many derivatives are stable in concentrated sulfuric
acid.30 These families have a very rich ring-functionalization
chemistry for both the Cp and arene ligands,29 and their
redox chemistry is well-known with reversibility properties.31
Despite their thermal robustness, these complexes are sensi-
tive to visible light, and visible-light-induced exchange of
the arene ligand by various other ligands is known. In
dichloromethane, the arene ligand can be exchanged by a
more electron-rich arene,32 whereas in acetonitrile, piano-
stool complexes can be obtained upon visible-light photolysis
in the presence of potential two-electron ligands.21,33 In a
preliminary communication, we have reported visible-light-
induced exchange of the toluene ligand in the complexes
[(η5-C5H4R)Fe(η6-toluene)][PF6] by substituted cyclopenta-
dienyls leading to functional ferrocenes.34 We have now exten-
ded this useful and simple visible-light photolysis reaction to
new complexes of the type [(η5-C5H4R)Fe(η6-toluene)][PF6]
(R=benzylamino), [(η5-Cp*)Fe(η6-toluene)[PF6], and to bi-
Therefore, we have addressed the families of complexes [(η5-
C5H4R)Fe(η6-arene)][PF6] (R=functional group)29 as pre-
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Ruiz, J.; Astruc, D. Organometallics 1987, 6, 2605–2607. (c) Bunuel, E. E.;
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C14. (b) Catheline, D.; Astruc, D. J. Organomet. Chem. 1984, 269, C33–C35.
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1789. (b) Ornelas, C.; Ruiz, J.; Belin, C.; Astruc, D. J. Am. Chem. Soc. 2009, 131,
590–601.
5
nuclear fulvalene complexes [(μ2,η5,η0 -Fv)Fe(η6-toluene)][PF6]
(30) (a) Nesmeyanov, A. N.; Vol’kenau, N. A.; Bolesova, I. N. Tetra-
hedron Lett. 1963, 4, 1725–1729. (b) Astruc, D.; Dabard, R. Tetrahedron 1976,
32, 245–249.
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D.; Hamon, J.-R.; Michaud, P. Organometallics 1983, 2, 211–218. (b) Lacoste,
M.; Varret, F.; Toupet, L.; Astruc, D. J. Am. Chem. Soc. 1987, 109, 6504–6506.
(c) Desbois, M.-H.; Astruc, D.; Guillin, J.; Varret, F. J. Am. Chem. Soc. 1989,
111, 5800–5809.
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3537–3538.
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M.; Nakamura, E. J. Am. Chem. Soc. 2002, 124, 9354–9355.
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(b) Catheline, D.; Astruc, D. J. Organomet. Chem. 1984, 272, 417–426. (c) Ruiz,
J.; Astruc, D. Inorg. Chim. Acta 2008, 361, 1–4.
(32) (a) Gill, T. P.; Mann, K. R. Inorg. Chem. 1980, 19, 308–312. (b) Gill,
T. P.; Mann, K. R. J. Organomet. Chem. 1981, 216, 65. (c) Hamon, J.-R.;
Michaud, P.; Astruc, D. J. Am. Chem. Soc. 1981, 103, 758–766.
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Article
Inorganic Chemistry, Vol. 49, No. 4, 2010 1915
Scheme 1
(Fv=fulvalene), and arenes containing two cyclopentadienyl
rings. The overall results are reported and discussed here.
obtained with [CpFe(η6-C6H5CH3)][PF6]. Accordingly, the
PF6- anion was chosen for the overall study.
3. Selective Synthesis of Heterobifunctional Ferrocenes
by Visible-Light Photolysis of [(η5-C5H4R)Fe(η6-toluene)]-
[PF6] with Functional Cyclopentadienyl Salts. The reaction
of the complexes [(η5-C5H4R)Fe(η6-toluene)][PF6], with
substituted cyclopentadienyl salts C5H4R0Li or C5H4R0Na
in dichloromethane or acetonitrile under visible light
(standard 100 W lamp), also proceeds readily in a few
hours to give the expected substituted ferrocene derivative
(eq 2, Table 1). The reaction yields are fair to good (entries
3 to 6 and 8 to 11), except if the cyclopentadienyl derivative
bears a strong ligand such as a carboxylic acid function in
[(η5-C5H4CO2H)Fe(η6-toluene)][PF6] (11, entry 7). In
these cases, the yields are lower. When the Cp ligand in
the salt [(η5-C5H4R)Fe(η6-toluene)][PF6] bears an amino
oramido group, theyields are onlymodest. Conjugation of
these groups with the Cp ligand provokes a hypsochromic
shift rendering visible photolysis somewhat more difficult.
The solvent is chosen in such a way that both the salts
[CpFe(η6-toluene)][PF6] and C5H4RM(M = Li or Na) are
soluble, otherwise the reaction does not proceed.
Results
All reactions were carried out overnight using a desk lamp
outside an ordinary Schlenk flask, and all the results are
gathered in Table 1.
1. Visible-Light Photolysis of [CpFe(η6-toluene)][PF6]
with Cyclopentadienyl Salts. The reaction of [CpFe(η6-
toluene)][PF6] with substituted cyclopentadienyl salts
C5H4R0Li or C5H4R0Na in dichloromethane or acetoni-
trile under visible light (standard 100 W lamp) proceeds
readily in a few hours to give the expected substituted
ferrocene derivative quantitatively or in high yield (eq 1,
Table 1, 7-9 entries 2-4) except if the cyclopentadienyl
derivative bears a strong ligand such as a phosphine in
C5H4PPh2Li (7, entry 2, 51% yield).
2. Optimization of the Counteranion and Arene in the
[CpFe(η6-arene)][X] Salt. The visible-light photolysis can
be carried out using various arene ligands and counteranions
X- in [CpFe(η6-arene)][X] salt. The benzene and mono- or
polymethylbenzene complexes are sensitive to visible light, but
the hexamethylbenzene complexes [CpFe(η6-C6Me6)][X] are
no longer so. The durene and pentamethylbenzene complexes
are solids, and their complexes are synthesized in methylcy-
clohexane or decalin.20a They are also more expensive than
toluene, xylenes, and mesitylene, and were thus not used. The
benzene, toluene, xylene, and mesitylene complexes are visi-
ble-light sensitive, and their syntheses proceed in high yields
without the need of an additional solvent. Thus, they are all
suitable as precursors. We have carried out all the reactions
using the toluene complexes, because toluene is easily removed
under vacuum after photolysis.
The influence of the nature of the counteranion was
examined with the counteranions PF6-, BF4-, and BPh4-in
the series of complexes [CpFe(η6-C6H6)][X] inthevisible-light
photolysis in the presence of NaC5H4CO2CH3 in acetonitrile .
It was found that the yields of the syntheses of carboxymethyl-
ferrocene using this visible-light-photolysis method were 98%
with PF6-, 82% with BF4-, and 80% with BPh4-. The yield
(98%) obtained with [CpFe(η6-C6H6)][PF6] was the same as
A variety of precursor complexes [(η5-C5H4R)Fe(η6-
toluene)][PF6] with different R groups are accessible by
reaction of 1,10-dialkylferrocenes, 1,10-dichloroferrocene,
monoacyl-ferrocenes, or ferrocenecarboxylic acid with
toluene in the presence of aluminum chloride. The reac-
tions of these complexes [(η5-C5H4R)Fe(η6-toluene)][PF6]
bearing a substituent on the cyclopentadienyl ring work well
with the 100 W visible light if the reactants are soluble in the
reaction solvent, providing good yields of the 1,10-hetero-
disubstituted ferrocene derivative (9-16, entries 5-12). The
complex [(η5-C5H4Cl)Fe(η6-toluene)][PF6] reacts with amines
such as benzylamine at 130 °C to yield the benzylaminocy-
clopentadienyl mixed-sandwich salt that also undergoes the
visible-light-induced arene substitution by a functional
cyclopentadienyl salt (Scheme 1, 16, entry 12).
4. Synthesis of Functional Pentamethylferrocenes. Visi-
ble-light photolysis of the complex [Cp*Fe(η6-toluene)]-
[PF6], under these conditions, does not work, and the
starting compound is quantitatively recovered. In this case

1916 Inorganic Chemistry, Vol. 49, No. 4, 2010
Diallo et al.
Scheme 2
(only), photolytic synthesis requires the use of a UV lamp
that provides the desired sandwich derivative [Cp*Fe(η5-
C5H4R)] (17, entry 13). The alternative synthesis of these
later complexes (R = H) starting from [CpFe(η6-toluene)-
[PF6] and Cp*Na in MeCN using visible light does not
work at all, however. Only ferrocene is formed by light-
induced decomposition, and the awaited 1,2,3,4,5-penta-
methylferrocene derivative is not formed (Scheme 2).
5. Synthesis of Functional Biferrocenes by Visible-Light
Photolysis of [(μ2,η5,η05-Fv)Fe2(η6-toluene)2][PF6]2 (Fv =
fulvalene) in the Presence of a Functional Cyclopentadienyl
Salt. These reactions of functional ferrocenes have been
extended to the syntheses of functional biferrocenes. The
fulvalene bis (toluene) diiron salt, accessible by reaction of
biferrocene with toluene (Scheme 3), is photolyzed with visible
light in acetonitrile in the presence of a functional cyclopenta-
dienyl salt to yield the biferrocene derivative bearing the
functional group on both free cyclopentadienyl ligands.
This reaction was successfully carried out in high yields
in both cases of acetyl-cyclopentadienylsodium and car-
boxymethylcyclopentadienylsodium (Scheme 3, 18 and
19, entries 14 and 15).
6. Synthesis of Functional Biferrocenes by Visible-Light
Photolysis of [CpFe(η6-toluene)][PF6] in the Presence of a
Bis-cyclopentadienyl Dianion. The other way to synthesize
biferrocene derivatives using the visible-light photolysis
reaction consist in photolyzing [CpFe(η6-toluene)][PF6] in
the presence of a bis(cyclopentadienyl) dianion. This has
been achieved with the dianion (C5H4)2-1,4-C6H4Na2, yield-
ing the biferrocene derivative 1,4-C6H4(FcCH2)2 (eq 3, Fc=
ferrocenyl, 20, entry 16), although the yield is low for this
reaction that is carried out in tetrahydrofuran (THF), a
solvent compatible with the solubilization of both substrates.
decay and intersystem crossing from 1E2 and 1E1 LF excited
states resulting from absorption.35 The resulting destabiliza-
tion can be compared to that provided by monoelectronic
reduction of the d6 cations to the d7 1E1 state.31 In both cases,
nucleophilic attack at the iron center is fast leading to ligand
substitution if the nucleophile is a ligand. It is likely that
ligand substitution readily operates with solvents such as
CH3CN and THF that are relatively good ligands, and even
also CH2Cl2 that is a very weak ligand. All these temporary
ligands are displaced by stronger hydrocarbon ligands. Arene
exchange only proceeds in CH2Cl2 that is a weak enough
ligand, whereas arene exchange does not work in CH3CN. On
the other hand, the cyclopentadienyl anion is a much stronger
ligand than the arenes and can displace three CH3CN ligands
even in the thermally stable complex [Cp*Fe(NCMe)3][PF6].
As a result, the thermally robust complexes [(η5-C5H4R)Fe-
(η6-toluene)][PF6] are ideal sources of the “12-electron”
species (η5-C5H4R)Feþ or weakly coordinated forms in the
presence of a simple external visible-light source. The choice
of toluene as the potential leaving group in the starting
materials results from the high yield of synthesis of the toluene
complexes by ligand exchange from ferrocenes, from its easy
decomplexation using visible light, its low cost, lack of high
toxicity and easy removal under vacuum from the final ferro-
cene derivative. When the number of methyl groups on the
arene ligand is increased, the light absorption undergoes a
hypsochromic shift, and the fully methylated hexamethylben-
zene complex [CpFe(η6-C6Me6)][PF6], as [Cp*Fe(η6-toluene)]-
[PF6], cannot be photolyzed by visible light. UV light is
required to photolyze these complexes and obtain arene/
cyclopentadienyl substitution. A strong hypsochromic shift is
also found in the complexes of the type [CpFe(η6-C6H5-
NHR)][PF6] because of the contribution of the mesomeric
iminocyclohexadienyl structure [CpFe(η5-C6H5(=NþHR)]-
[PF6],29c the cyclohexadienyl complexes [CpFe(η5-C6H5-
(= XH R) ] ( X = C or N þ) being, as most ferrocene deriva-
tives, insensitive to visible light in common organic solvents.
The visible-light-induced arene/cyclopentadienyl substitution
works well with fulvalene-diiron-bis(toluene) dication and
less well for bis(cyclopentadienyl) derivatives for which the
solvent often is a difficult problem. The failure of the reaction
with Cp*Na indicated that steric bulk around the incoming
cyclopentadienyl ligand is a problem. Thus, the limits of this
reaction are the steric bulk of the entering Cp ligand (for
Discussion
(35) (a) McNair, A. M.; Schrenck, J. L.; Mann, K. R. Inorg. Chem. 1984,
23, 2633–2637. (b) Schrenck, J. L.; McNair, A. M.; Mann, K. R. Inorg. Chem.
1986, 25, 3501–3504.
Mechanistic studies have identified the photoexcited state
as the distorted 3E1 ligand field (LF) state produced by rapid

Article
Inorganic Chemistry, Vol. 49, No. 4, 2010 1917
Scheme 3
instance with C5Me5) and the solubility (in particular with
entering bis(cyclopentadienyl) anions).
Electrochemical measurement was recorded under nitrogen
atmosphere. Solvent: dichloromethane; temperature: 20 °C;
supporting electrolyte: [n-Bu4N][PF6], 0.1 M; working and
counter electrodes: Pt; reference electrode: Ag; internal refer-
Concluding Remarks
ence: FeCp*2 (Cp*= η5-C5Me5); scan rate: 0.200 V s-1
.
The visible-light photolysis of [(η5-C5H4R)Fe(η6-toluene)]-
[PF6] in the presence of functional cyclopentadienyl salts
using an ordinary 100 W lamp allows facile syntheses of 1,10
heterobifunctional ferrocenes and biferrocenes. The simpli-
city of the reaction, and its extension to various ferrocenyl
substituents and functional groups including syntheses of
biferrocene derivatives is remarkable because various hetero-
bifunctional ferrocenes and biferrocenes could be made in this
way. The synthetic path is all the more powerful as the family
of the precursors [(η5-C5H4R)Fe(η6-toluene)][PF6] has a rich
chemistry related to the multiple possibilities of functionaliza-
tion of the Cp ligand.29
The limitations are the following: (i) the difficulty to extend
the reaction to the permethylated complexes [Cp*Fe(η6-
toluene)][PF6] that require UV light instead of visible light
to introduce functional cyclopentadienyl subsituents, (ii) the
bulk of sterically crowded incoming cyclopentadienyls result-
ing in decreased reaction yields, and (iii) the poor solubility of
some substituted cyclopentadienyl salts that needs to be
circumvented to carry out the photolytic reactions.
Elemental analyses were performed by the Centre of
Microanalysis of the CNRS at Solaize, France. The mass
spectra were performed by the CESAMO (Bordeaux, France)
on a QStar Elite mass spectrometer (Applied Biosystems).
The instrument is equipped with an ESI source, and spectra
were recorded in the positive mode. The electrospray needle
was maintained at 5000 V and operated at room tempera-
ture. Samples were introduced by injection through a 10 mL
sample loop into a 200 mL/min flow of methanol from the
LC pump.
The complexes [(η5-C5H5)Fe(η6-toluene)][PF6],36 Na[η5-C5H4-
COCH3],37 Na[η5-C5H4CO2CH3],38 Na2[1,4-C6H4(CH2C5H4)2],38
Li[η5-C5H4P(C6H5)2],39 Li[η5-C5H4Si(CH3)2CH2Cl],40 [(η5-C5-
H4CO2H)Fe(η6-toluene)][PF6],41 [(η5-C5H4COCl)Fe(η6-toluene)]-
[PF6],41 [(η5-C5H4COMe)Fe(η6-toluene)][PF6],42 [(η5-C5H4Cl)Fe-
5
(η6-toluene)][PF6],43 [Fe2Fv(η5-C5H5)2] (Fv = μ2-η5, η0 -fulva-
lenediyl),44 [(η5-C5H4Me)Fe(η6-toluene)][PF6],36 and [(η5-Cp*)Fe-
(η6-toluene)][PF6]45 were synthesized according to the references.
Synthesis of [(η5-C5H4CO2Me)Fe(η6-toluene)][PF6], 1. So-
dium methoxide (0.276 g, 5 mmol) was added to a dichloro-
methane/methanol (1:1) solution of [(η5-C5H4COCl)Fe(η6-
toluene)][PF6] (1 g, 2.47 mmol). This solution was stirred for
4 h at room temperature, then the solvent was removed under
vacuum, and the residue was dissolved in dichloromethane and
washed with an aqueous solution of HPF6. The organic layer
was dried with sodium sulfate, filtered, and the solvent was
In conclusion, this new, remarkably simple and selective
synthetic route to functional ferrocenes and biferrocenes is
very useful because it is complementary to classic synthetic
routes and, in particular, it should allow the introduction of
redox-robust ferrocene and biferrocene derivatives into nano-
scopic devices.
(36) Nesmeyanov, A. N.; Vol’keneau, N. A.; Bolesova, I. N. Doklady
Akad. Nauk S.S.R 1963, 149, 615–618.
(37) Hart, W. P.; Macomber, D. W.; Rausch, M. D. J. Am. Chem. Soc.
1980, 102, 1196–1198.
Experimental Section
(38) Dory, T. S.; Zuckerman, J. J. J. Organomet. Chem. 1984, 264, 295–
303.
General Data. Acetonitrile was predried over P2O5 and
distilled under argon immediately prior to use. THF was
predried over Na foil and distilled from sodium-benzophe-
none anion under argon immediately prior to use. Dichlor-
omethane was distilled from calcium hydride just before use.
The benzylamine and the triethylamine were distilled from
LiAlH4 just before use. All manipulations were carried out
using Schlenk techniques or in a nitrogen-filled Vacuum
Atmosphere drylab.
(39) Mathey, F.; Lampin, J.-P. Tetrahedron 1975, 31, 2685–2690.
ꢀ
ꢀ
(40) Ciruelo, G.; Cuenca, T.; Gomez, R.; Gomez-Sal, P.; Martin, A.
J. Chem. Soc., Dalton Trans. 2001, 1657–1663.
(41) Roman, E.; Dabard, R.; Moinet, C.; Astruc, D. Tetrahedron Lett.
1979, 20, 1433–1436.
(42) Astruc, D.; Dabard, R. Bull. Soc, Chim. Fr. 1975, N° 11-12,
2571-2574.
(43) Nesmeyanov, A. N.; Vol’keneau, N. A.; Bolesova, I. N. Doklady
Akad. Nauk S.S.R. 1966, 166, 607–610.
1H NMR spectra were recorded at 25 °C with a Bruker AC
300 (300 MHz) spectrometer. 13C NMR spectra were obtained
in the pulsed FT mode at 75 MHz, 31P NMR spectra were
obtained in at 81 MHz, and 29Si NMR spectra were obtained in
at 59.6 MHz with a Bruker AC 300 spectrometer. All chemical
shifts are reported in parts per million (δ, ppm) with reference to
Me4Si (TMS).
(44) (a) Perevalova, E. G.; Nesmeyanova, O. A. Doklady Akad. Nauk S.S.
S.R. 1960, 132, 1093–1094. (b) Nesmeyanova, O. A.; Perevalova, E. G. Doklady
Akad. Nauk S.S.S.R. 1959, 126, 1007–1008. (c) Rausch, M. D. Inorg. Chem.
1962, 1, 414–417. (d) Shechter, H.; Helling, J. F. J. Org. Chem. 1961, 26, 1034–
1037. (e) Rausch, M. D. J. Org. Chem. 1961, 26, 1802–1805.
ꢀ
(45) Astruc, D.; Hamon, J.-R. ; Lacoste, M.; Desbois, M.-H. ; Roman, E.
In Organometallic Synthesis; King, R. B., Ed.; Academic Press: New York,
1988; Vol. IV, pp 172-187.

1918 Inorganic Chemistry, Vol. 49, No. 4, 2010
Diallo et al.
removed under vacuum. Precipitation with dichloromethane/
ether yielded 0.873 g of an orange powder (85% yield).
1H NMR (300 MHz, CD3COCD3) δppm: 2.52 (s, 3H, CH3-
C6H5), 3.96 (s, 3H, CH3CO), 5.39 (s, 2H, CpCOCH3), 5.63 (s, 2H,
CpCOCH3), 6.48 (s, 5H, C6H5CH3).
CH2C6H5), 4.64, 4.77 (CH of CpNH), 5.71 (s, 1H, NHCp), 5.99
(s, 5H, C6H5CH3), 7.32 (m, 5H, C6H5CH3).
13C NMR (75 MHz, CD3COCD3) δppm: 20.2 (CH3C6H5),
49.2 (NHCH2), 60.1, 72.2 (CH of CpNH), 86.4, 87.5, 88.5 (C6-
H5CH3), 102.8 (Cq of CpNH), 128.5, 128.8, 129.6 (C6H5CH2).
Anal. Calcd for C19H20F6FeNP: C 49.27; H 4.35; found: C
49.37; H 4.34
13C NMR (75 MHz, CD3COCD3) δppm: 20.1 (CH3C6H5),
53.5 (CH3CO2Cp), 78.2, 79.8 (CH of CpCO2CH3), 80.7
(Cq of CpCO2CH3), 88.6, 90.0, 90.7 (CH of C6H5CH3), 106.1
(Cq of C6H5CH3), 166.9 (CO2Cp).
5
Synthesis of [Fe2Fv(η6-toluene)2][PF6]2, 5 (Fv = μ2-η5, η0 -
5
fulvalenyl). [Fe2Fv(η5-C5H5)2] (Fv = μ2-η5, η0 -fulvalenyl) (2 g,
Anal. Calcd for C14H15F6FeO2P: C 40.41; H 3.63; found:
C 40.34.56; H 3.63.
5.4 mmol), aluminum chloride (7.2 g, 54 mmol), Al powder
(0.146 g, 5.4 mmol), and H2O (0.097 mL, 5.4 mmol) are mixed
under N2 and heated at 115 °C for 12 h in 50 mL of toluene. After
hydrolysis at 0 °C, aqueous NH3 is added to the aqueous layer to
remove Al3þ, and then aqueous HPF6 (0.6 mL, 10.8 mmol) is
added to the filtrate to precipitate the salt. Re-precipitation by
addition of excess CH2Cl2 to an acetone solution provides 1.5 g
(38% yield) of powdered salt.
ESI mass spectrum: calcd m/z for Mþ (C14H15FeO2) 271.113;
found 271.042 (Mþ).
Synthesis of [(η5-C5H4CO2CH2CCH)Fe(η6-toluene)][PF6], 2.
HOCH2CCH (0.11 mL, 1.86 mmol) was added to a dichlor-
omethane solution of triethylamine (1 mL) and [(η5-C5H4-
COCl)Fe(η6-toluene)][PF6] (0.5 g, 1.24 mmol). This solution
was stirred for 4 h at room temperature. The solvent was
removed under vacuum, and the residue was dissolved in
dichloromethane and washed with an aqueous solution of
K2CO3 and with an aqueous solution of HPF6. The organic
layer was dried with sodium sulfate, filtered, and the solvent was
removed under vacuum. Precipitation with dichloromethane/
ether yielded 0.464 g of an orange powder (85% yield).
[(η5-C5H4CO2CH2CCH)Fe(η6-toluene)][PF6]: 1H NMR (300
MHz, CD3COCD3) δppm: 2.56 (s, 3H, CH3C6H5), 3.28 (s, 1H,
CtCH), 5.04 (d, 2H, CHtCCH2), 5.43 (s, 2H, CH of CpCO2-
CH3), 5.68 (s, 2H, CH of CpCO2CH3), 6.50 (s, 5H, C6H5CH3).
13C NMR (75 MHz, CD3COCD3) δppm: 20.4 (CH3C6CH5),
54.1 (CHtCCH2), 77.8 (CHtCCH2), 78.4 (CH of CpCO2), 78.5
(CtCH), 79.6 (CH of CpCO2), 80.2 (Cq of CpCO2), 88.8, 90.1,
90.8 (CH of C6H5CH3), 106.4 (Cq of C6H5CH3), 166.1 (CO2CH3).
ESI mass spectrum: calcd m/z for Mþ (C16H15FeO2); found
295.043 (Mþ).
[Fe2Fv((η6-toluene)][PF6]: 1H NMR (300 MHz, CD3COCD3)
δppm: 2.28 (s, 6H, CH3C6H5), 5.42 (s, 4H, CH of Fv), 5.74 (s, 4H,
CH of Fv), 6.22 (s, 10H, C6H5CH3).
13C NMR (75 MHz, CD3COCD3) δppm: 20.2 (CH3C6H5), 75.5,
78.9 (CH of Fv), 88.4, 89.8, 90.4 (C6H5CH3), 105.5 (Cq of Fv).
Anal. Calcd for C24H24F12Fe2P2: C 40.37; H 3.39; found: C
39.70 ; H 3.78
General Procedure for the Photochemical Reactions. In a
double-wall Schlenk flash, amounts of complex [(η5-C5H4R)Fe-
(η6-toluene)][PF6] and 2 equiv of cyclopentadienyl salt MC5H4R0
(M = Li or Na) or 4 equiv of disodium (phenylenedimethylene)-
dicyclopentadienide salt 1,4-C6H4(CH2C5H4)2Na2 were dissolved
in dry acetonitrile, dichloromethane or THF. The solution was
irradiated with visible light for 12 h, under magnetic stirring and
water cooling on the exterior wall of the Schlenk tube. The solvent
was removed under vacuum, and the crude product was dissolved
in dichloromethane. The solution was washed several times with
water, and the organic phase was dried over Na2SO4. Dichlor-
omethane was removed under vacuum, and the crude product was
then adsorbed on silica and purified by column chromatography
(SiO2) using the mixture pentane- diethyl ether (90:10) as eluent.
Synthesis of [(η5-C5H5)Fe(η5-C5H4CO2Me)],46 6. The com-
plex 6 was synthesized from [(η5-C5H5)Fe(η6-toluene)][PF6]
(0.25 g, 0.698 mmol) and Na(η5-C5H4CO2CH3) (0.204 g, 1.40
mmol) following the general procedure for the photochemical
reactions. A 0.167 g portion of 6 was obtained (98% yield).
1H NMR (300 MHz, CDCl3) δppm: 3.80 (s, 3H, CH3CO2Cp),
4.20 (s, 5H, Cp), 4.39 (s, 2H, CH of CpCO2CH3), 4.80 (s, 2H, CH
of CpCO2CH3).
Synthesis of [(η5-C5H4CONHCH2C6H5)Fe(η6-toluene)]-
[PF6], 3. A 2.3 mL portion of benzylamine was added to a
dichloromethane solution of [(η5-C5H4COCl)Fe(η6-toluene)]-
[PF6] (0.5 g, 1.24 mmol), and this solution was stirred for 4 h
at room temperature. The solvent was removed under va-
cuum, and the residue was dissolved in dichloromethane and
washed with an aqueous solution of HPF6. The organic layer
was dried with sodium sulfate, filtrated, and the solvent was
removed under vacuum. Precipitation with dichloromethane/
ether yielded 0.333 g of an orange powder (60% yield).
[(η5-C5H4CONHCH2C6H5)Fe(η6-toluene)][PF6]: 1H NMR
(300 MHz, CD3COCD3) δppm: 2.45 (s, 3H, CH3C6H5), 4.57 (s,
2H, CH2C6H5), 5.31 (s, 2H, CH of CpCO), 5.65 (s, 2H, CH of
CpCO), 6.28 (s, 5H, CH3C6H5), 7.27 (m, 5H, C6H5CH2), 8.34 (s,
1H, NHCH2).
13C NMR (75 MHz, CDCl3) δppm: 51.5 (CH3CO2Cp), 69.6
(Cp), 70.0, 71.2 (CH of CpCO2CH3), 172.2 (CO2).
IR (cm-1): 1702.33 (γCO2Me).
Synthesis of [(η5-C5H5)Fe(η5-C5H4PPh2)],47 7. The complex
7 was synthesized from [(η5-C5H5)Fe(η6-toluene)][PF6] (0.358 g,
1 mmol) and Li[η5-C5H4P(C6H5)2] (0.512 g, 2 mmol) following
the general procedure for the photochemical reactions. A 0.189 g
portion of 7 was obtained (51% yield).
13C NMR (75 MHz, CD3COCD3) δppm: 19.0 (CH3C6H5),
43.3 (NHCH2), 75.9, 78.0 (CH of CpCO), 85.2 (Cq of CpCO),
87.3, 88.7, 89.6 (CH3C6H5), 127.2, 128.0, 128.4 (C6H5CH2),
138.8 (CONH).
Anal. Calcd for C20H20F6FeNOP: C 48.91; H 4.10; found: C
48.46; H 4.03
1H NMR (300 MHz, CDCl3) δppm: 4.10 (s, 5H, Cp), 4.14 (m,
2H, CH of CpP(Ph)2), 4.40 (m, 2H, CH of CpP(Ph)2), 7.30-7.40
(m, 10H, CH of P(Ph)2).
ESI mass spectrum: calcd m/z for Mþ (C20H20FeNO)
346.224; found 346.089 (Mþ).
13C NMR (75 MHz, CDCl3) δppm: 69.1 (Cp), 70.7, 72.8 (CH of
CpP(Ph)2), 75.8 (Cq of CpP(Ph)2), 128.1, 133.3 (CH of P(Ph)2),
139.0 (Cq of P(Ph)2).
Synthesis of [(η5-C5H4NHCH2C6H5)Fe(η6-toluene)][PF6], 4.
[(η5-C5H4Cl)Fe(η6-toluene)] [PF6] (1.170 g, 2.5 mmol) was dis-
solved in a solution of benzylamine (1.6 mL, 12.5 mmol) and
triethylamine (0.4 mL, 2.5 mmol). This solution was stirred for
24 h at 130 °C. The solvent was removed under vacuum, and the
residue was dissolved in dichloromethane and washed with an
aqueous solution of HPF6. The organic layer was dried with
sodium sulfate, filtrated, and the solvent was removed under
vacuum. Precipitation with dichloromethane/ether yielded
0.678 g of an orange powder (58% yield).
31P NRM (81 MHz, CDCl3) δppm: -15.3.
Synthesis of [(η5-C5H5)Fe(η5-C5H4SiMe2CH2Cl)],48 8. The
complex 8 was synthesized from [(η5-C5H5)Fe(η6-toluene)]-
(46) Barisic, L.; Rapic, V.; Pritzkow, H.; Pavlovic, G.; Nemet, I.
J. Organomet. Chem. 2003, 682, 131–142.
(47) Butler, I. R.; Cullen, W. R. Organometallics 1986, 5, 2537–2542.
(48) Altmann, R.; Gausset, O.; Horn, D.; Jurkschat, K.; Schrmann, M.;
Fontani, M.; Zanello, P. Organometallics 2000, 19, 430–443.
[(η5-C5H4NHCH2C6H5)Fe(η6-toluene)][PF6]: 1H NMR (300
MHz, CD3COCD3) δppm: 2.40 (s, 3H, CH3C6H5), 4.30 (d, 2H,

Article
Inorganic Chemistry, Vol. 49, No. 4, 2010 1919
[PF6] (0.358 g, 1 mmol) and Li[η5-C5H4Si(CH3)2CH2Cl] (0.357 g, 2
mmol) following the general procedure for the photochemical
reactions in dichloromethane. The crude product was then ad-
sorbed on silica and purified by column chromatography (SiO2)
using pentane as eluent. A 0.205 g portion of 8 was obtained (80%
yield).
procedure for the photochemical reactions. A 0.227 g portion
of 7 was obtained (85% yield).
1H NMR (300 MHz, CDCl3) δppm: 2.53 (m, 1H, CHtC), 3.85
(s, 3H, CH3CO2Cp), 4.45 (m, 4H, CH of CpCO2CH3 and CpCO2-
CH2CCH), 4.84 (m, 6H, CH of CpCO2CH3, CpCO2CH2CCH and
CH2 of CH2CCH).
1H NMR (300 MHz, CDCl3) δppm: 0.41 (s, 6H, Si(CH3)2),
2.91 (s, 2H, ClCH2Si(CH3)2), 4.18 (s, 7H, CH of Cp and CpSi-
(CH3)2), 4.41 (m, 2H, CH of CpSi(CH3)2).
13C NMR (75 MHz, CDCl3) δppm:51.7(CHtCCH2),51.8(CH3-
CO2Cp), 71.5, 72.7 (CH of CpCO2CH3 and CpCO2CH2CCH), 74.7
(CHtCCH2), 78.1 (CtCH), 169.7 (CO2CH2) 170.7 (CO2CH3).
13C NMR (75 MHz, CDCl3) δppm: -3.6 (Si(CH3)2), 31.2
(ClCH2), 67.3 (Cq of CpSi(CH3)2), 68.2 (Cp), 71.2, 73.1 (CH of
CpSi(CH3)2).
IR (cm-1): 1718.05 (γCO2); 2120.36 (γCtC)
.
Anal. Calcd for C16H14FeO4: C 58.93; H 4.33; found: C 59.00;
H 4.46
ESI mass spectrum: calc. m/z for Mþ (C16H14FeO4) 326.132;
found 327.034 (Mþ), 349.014 (MNaþ).
29Si NMR (59.6 MHz, CDCl3) δppm: -1.46.
Synthesis of [(η5-C5H4CO2Me)Fe(η5-C5H4COMe)],49 9. The
complex 9 was synthesized from [(η5-C5H4CO2Me)Fe(η6-
toluene)][PF6], 1 (0.250 g, 0.6 mmol) and Na[η5-C5H4COCH3]
(0.156 g, 1.2 mmol) following the general procedure for the
photochemical reactions. A 0.151 g portion of 9 was obtained
(88% yield).
Synthesis of [(η5-C5H4CONHCH2C6H5)Fe(η5-C5H4CO2Me)],
13. The complex 13 was synthesized from [(η5-C5H4CON-
HCH2C6H5)Fe(η6-toluene)][PF6], 3 (0.255 g, 0.57 mmol) and
Na[η5-C5H4CO2CH3] (0.166 g, 1.14 mmol) following the general
procedure for the photochemical reactions. A 0.150 g portion of
13 was obtained (70% yield).
The complex 9 was also obtained from [(η5-C5H4COMe)Fe-
(η6-toluene)][PF6] and Na[η5-C5H4CO2CH3] in 95% yield.
1H NMR (300 MHz, CDCl3) δppm: 2.40 (s, 3H, CH3COCp),
3.84 (s, 3H, CH3CO2Cp), 4.42 (m, 2H, CH of CpCOCH3), 4.51
(m, 2H, CH of CpCO2CH3), 4.78 (m, 2H, CH of CpCOCH3),
4.82 (m, 2H, CpCO2CH3).
1H NMR (300 MHz, CDCl3) δppm: 3.76 (s, 3H, CH3CO2Cp),
4.36 (d, 4H, CH of CpCONH and CpCO2CH3), 4.57 (m, 6H, CH
of CpCONH and CpCO2CH3, CH2 of CONHCH2Ph), 6.65 (s,
1H, NHCO), 7.32 (m, 5H, C6H5).
13C NMR (75 MHz, CDCl3) δppm: 43.6 (NHCH2), 51.8
(CH3CO2Cp), 70.0, 71.6, 72.7 (CH of CpCONH and CpCO2CH3),
127.4, 127.9, 128.6 (C6H5CH2), 138.7 (Cq of C6H5CH2), 169.2
(CONHCH2), 171.6 (CO2CH3).
13C NMR (75 MHz, CDCl3) δppm: 27.5 (CH3COCp), 51.7
(CH3CO2Cp), 70.9, 71.5, 72.6, 73.4 (CH of CpCO2CH3 and
CpCOCH3), 80.4 (Cq of CpCO2CH3 and CpCOCH3), 170.6
(CO2CH3), 201.3 (COCp).
IR (cm-1): 1716.43 (γCO2).
IR (cm-1): 1671.85 (γCO); 1715.73 (γCO2Me).
Anal. Calcd for C20H19FeNO3: C 63.68; H 5.09; found: C
Synthesis of [(η5-C5H4COMe)Fe(η5-C5H4SiMe2CH2Cl)], 10.
The complex 10 was synthesized from [(η5-C5H4COMe)Fe(η6-
toluene)][PF6] (0.384 g, 1 mmol) and Li[η5-C5H4Si(CH3)2CH2Cl]
(0.357 g, 2 mmol) following the general procedure for the photo-
chemical reactions in dichloromethane. A 0.251 g portion of 10
was obtained (75% yield).
63.48; H 4.89.
ESI mass spectrum: calc. m/z for Mþ (C20H19FeNO3)
377.223; found 378.0796 (Mþ), 400.0617 (MNaþ).
Synthesis of [(η5-C5H4Cl)Fe(η5-C5H4CO2Me)], 14. The com-
plex 14 was synthesized from [(η5-C5H4Cl)Fe(η6-toluene)][PF6]
(0.422 g, 1.13 mmol) and Na[η5-C5H4CO2CH3] (0.330 g, 2.26
mmol) following the general procedure for the photochemical
reactions. A 0.283 g portion of 13 was obtained (90% yield).
1H NMR (300 MHz, CDCl3) δppm: 3.83 (s, 3H, CH3CO2Cp),
4.09 (m, 2H, CH of CpCl), 4.42 (m, 4H, CH of CpCl and
CpCO2CH3), 4.87 (m, 2H, CH of CpCO2CH3).
1H NMR (300 MHz, CD3COCD3) δppm: 0.41 (s, 6H, Si(CH3)2),
2.40 (s, 3H, CH3COCp), 2.91 (s, 2H, ClCH2Si(CH3)2), 4.18 (s, 2H,
CH of Cp and CpSi(CH3)2), 4.40 (m, 4H, CH of CpCOCH3 and
CpSi(CH3)2), 4.65 (m, 2H, CH of CH of CpCOCH3).
13C NMR (75 MHz, CDCl3) δppm: -3.6 (Si(CH3)2), 27.5
(CH3COCp), 31.2 (ClCH2), 67.3 (Cq of CpSi(CH3)2), 71.2, 71.5,
73.1, 73.4 (CH of CpCO2CH3 and CpSi(CH3)2), 80.4 (Cq of
CpCOCH3), 202.0 (CH3CO).
13C NMR (75 MHz, CDCl3) δppm: 51.6 (CH3CO2Cp), 67.6,
69.2, 71.8, 73.2 (CH of CpCl and CpCO2CH3), 93.2 (Cq of
CpCl), 170.7 (CO2CH3).
29Si NMR (59.6 MHz, CDCl3) δppm: -1.46.
Anal. Calcd for: C12H11ClFeO2 for calcd: C 51.75; H 3.98;
found: C 52.02; H 4.48
IR (cm-1): 1626.30 (γCO).
Synthesis of [(η5-C5H4CO2H)Fe(η5-C5H4COMe)],50 11. The
complex 11 was synthesized from [(η5-C5H4CO2H)Fe(η6-toluene)]-
[PF6] (0.250 g, 0.6 mmol) and Na[η5-C5H4COCH3] (0.156 g, 1.2
mmol) following the general procedure for the photochemical
reactions. The crude product was then adsorbed on silica and
purified by column chromatography (SiO2) using the mixture
methanol-diethyl ether (1:4) as eluent. A 0.025 g portion of 11
was obtained (15% yield).
ESI mass spectrum: calc. m/z for Mþ (C12H11ClFeO2)
278.518; found 278.988 (Mþ), 300.969 (MNaþ).
IR (cm-1): 1712.49 (γCO).
Synthesis of [(η5-C5H4Me)Fe(η5-C5H4COMe)], 15. The com-
plex 15 was synthesized from [(η5-C5H4Me)Fe(η6-toluene)][PF6]
(0.250 g, 0.672 mmol) and Na[η5-C5H4COCH3] (0.175 g, 1.35
mmol) following the general procedure for the photochemical
reactions. A 0.159 g portion of 15 was obtained (98% yield).
1H NMR (300 MHz, CDCl3) δppm: 1.87 (s, 3H, CH3Cp); 2.35
(s, 3H, CH3CO); 4.04 (s, 4H, CpCH3); 4.40 (m, 2H, CpCO); 4.65
(m, 2H, CpCO).
1H NMR (300 MHz, CDCl3) δppm: 2.40 (s, 3H, CH3COCp),
4.42 (m, 2H, CH of CpCOCH3), 4.52 (m, 2H, CH of CpCO2H),
4.78 (m, 2H, CH of CpCOCH3), 4.82 (m, 2H, CpCO2H).
13C NMR (75 MHz, CDCl3) δppm: 27.5 (CH3COCp), 70.9,
71.5, 72.6, 73.4 (CH of CpCO2H and CpCOCH3), 80.4 (Cq of
CpCO2H and CpCOCH3), 170.6 (CO2H), 201.3 (COCp).
IR (cm-1): 1637.16 (γCOCH3), 1725.05 (γCO2H).
13C NMR (75 MHz, CDCl3) δppm:13.7(CH3Cp), 27.5(CH3CO),
69.1, 70.1, 70.7, 73.1 (CH of CpCH3 and CpCOCH3), 79.6 (Cq of
CpCH3), 85.6 (Cq. of CpCO), 202.0 (CH3CO).
IR (cm-1): 1660 (γCO).
Synthesis of [(η5-C5H4CO2CH2CCH)Fe(η5-C5H4CO2Me)],
12. The complex 12 was synthesized from [(η5-C5H4CO2CH2-
CCH)Fe(η6-toluene)][PF6], 2 (0.361 g, 0.8 mmol) and Na[η5-
C5H4CO2CH3] (0.234 g, 1.6 mmol) following the general
Anal. Calcd for C13H14FeO: C 64.50; H 5.83; found: C 64.56;
H 5.74.
ESI mass spectrum: calc. m/z for Mþ (C13H14FeO) 242.101;
found 243.0473 (Mþ), 265.0289 (MNaþ).
Synthesis of [(η5-C5H4NHCH2C6H5)Fe(η5-C5H4CO2Me)], 16.
The complex 16 was synthesized from [(η5-C5H4NHCH2C6H5)-
Fe(η6-toluene)][PF6], 4 (0.287 g, 0.6 mmol) and Na[η5-C5H4CO2-
CH3] (0.175 g, 1.2 mmol) following the general procedure for the
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(49) Cakic Semencic, M.; Dropucic, M.; BarisicL; Rapic, V. Croat. Chem.
Acta 2006, 79, 599–612.
(50) Little, W. F.; Eisenthal, R. J. Am. Chem. Soc. 1960, 82, 1577–1580.

1920 Inorganic Chemistry, Vol. 49, No. 4, 2010
Diallo et al.
5
photochemical reactions. The crude product was then adsorbed on
silica and purified by column chromatography (SiO2) using dichlor-
omethane as eluent. A 0.096 g portion of 16 was obtained (44% yield).
1H NMR (300 MHz, CDCl3) δppm: 2.83 (s, 1H, NHCH2), 3.78
(s, 3H, CH3CO2Cp), 3.94 (s, 4H, CH of CpNH and CH2 of
CH2C6H5), 4.16 (s, 2H, CH of CpNH), 4.40 (m, 2H, CH of
CpCO2CH3), 4.83 (m, 2H, CH of CpCO2CH3), 7.29 (m, 5H,
C6H5CH2).
Synthesis of [(η5-C5H4COMe)2 Fe2Fv] (Fv = μ2-η5, η0 -fulva-
lenyl),51,52 19. The complex 19 was synthesized from [Fe2Fv((η6-
toluene)2][PF6]2, 5 (0.250 g, 0.3 mmol) and Na[η5-C5H4COCH3]
(0.302 g, 2.4 mmol) following the general procedure for the photo-
chemical reactions. The crude product was then adsorbed on silica
and purified by column chromatography (SiO2) using ethyl ace-
tate as eluent. A 0.136 g portion of 19 was obtained (87% yield).
1H NMR (300 MHz, CDCl3) δppm: 2.07 (s, 6H, CH3COCp),
4.19 (m, 12H, CH of CpCOCH3 and Fv), 4.49 (m, 4H, CH of
CpCOCH3).
13C NMR (75 MHz, CDCl3) δppm: 51.0 (CH3CO2Cp), 56.7
(CH2C6CH5), 64.7, 70.2, 71.2 (CH of CpCO2CH3 and CH of
CpNHCH2), 112.3 (Cq of CpNHCH2), 139.2 (Cq of CpCO2CH3),
172.4 (CO2CH3).
13C NMR (75 MHz, CDCl3) δppm: 27.6 (CH3CO2Cp), 67.6,
69.8, 70.7, 73.4 (CH of CpCOCH3 and Fv), 84.0 (Cq of Fv),
201.9 (COCH3).
ESI mass spectrum: calc. m/z for Mþ (C19H19FeNO2)
349.212; found 350.0838 (Mþ), 372.0650 (MNaþ).
Synthesis of [1,4-C6H4(CH2Fc)2] (Fc = C10H9), 20. The
complex 20 was synthesized from [(η5-C5H5)Fe(η6-toluene)]-
[PF6] (1.6 g, 4.5 mmol) and Na2[1,4-C6H4(CH2C5H4)2] (0.625
g, 2.25 mmol) in THF following the general procedure for
the photochemical reactions. The crude product was then
adsorbed on silica and purified by column chromatography
(SiO2) using the mixture pentane- diethyl ether (80:20) as
eluent. A 0.384 g portion of 20 was obtained (18% yield).
1H NMR (300 MHz, CDCl3) δppm: 3.56 (s, 4H, CH2Cp), 3.98
(m, 18H, CH of Cp and CpCH2), 6.99 (s, 4H, C6H4CH3).
13C NMR (75 MHz, CDCl3) δppm: 35.6 (CH2Cp), 67.5, 68.6
(CH of Cp and CpCH2), 88.2 (Cq of CpCH2), 128.2 (CH of
C6H4CH3), 139.2 (Cq of C6H4CH3).
Synthesis of [(η5-C5Me5)Fe(η5-C5H4CO2Me)],25 17. Solid
[(η5-C5Me6)Fe(η6-toluene)][PF6] (0.619 g, 1.4 mmol) was
added with stirring to a suspension of Na[η5-C5H4CO2CH3]
(0.409 g, 2.8 mmol) in acetonitrile. The solution was irradiated
with a Hanovia lamp (250 nm, 450 W) at -30 °C for 1 h. The
temperature was allowed to rise to ambient temperature. The
solvent was removed under vacuum, and the crude product
was dissolved in dichloromethane. The solution was washed
several times with water, and the organic phase was dried over
Na2SO4. Dichloromethane was removed under vacuum, and
the crude product was then adsorbed on silica and purified
by column chromatography (SiO2) using the mixture pentane-
diethyl ether (95:5) as eluent. A 0.121 g portion of 17 was obtained
(27% yield).
Anal. Calcd for: C28H26Fe2: C 70.92; H 5.53; found: C 70.77;
H 5.50.
ESI mass spectrum: calc. m/z for Mþ (C28H26Fe2) 474.208;
1H NMR (300 MHz, CDCl3) δppm: 1.77 (s, 15H, Me5C5), 3.80
(s, 3H, CH3CO2Cp), 3.98 (s, 2H, CH of CpCO2), 4.30 (s, 2H, CH
of CpCO2).
found 474.3 (Mþ).
Cyclic voltammetry (CH2Cl2; supporting electrolyte [n-
Bu4N]PF6; 293 K): only one reversible wave is observed because
of the equivalence of the two sufficiently separated ferrocenyl
groups,53 E1/2 = 0.525 V versus decamethylferrocene.54
13C NMR (75 MHz, CDCl3) δppm: 10.6 (Me5C5), 51.1
(CH3CO2Cp), 73.1 (CH of CpCO2CH3), 76.3 (CH of CpCO2CH3),
81.9 (Cq of C5Me5), 171.2 (CO2CH3).
5
Synthesis of [(η5-C5H4CO2Me)2 Fe2Fv] (Fv = μ2-η5, η0 -fulva-
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Acknowledgment. Financial support from the Universite
lenyl),51 18. The complex 18 was synthesized from [Fe2Fv((η6-
toluene)2][PF6]2, 5 (0.306 g, 0.4 mmol) and Na[η5-C5H4CO2CH3]
(0.467 g, 3.2 mmol) following the general procedure for the
photochemical reactions. The crude product was washed several
times with diethyl ether. A 0.179 g portion of 18 was obtained
(87%).
Bordeaux 1, the Centre National de la Recherche Scientifique
(CNRS), and the Agence Nationale pour la Recherche (ANR-
06-NANO-026-02) is gratefully acknowledged.
Supporting Information Available: 1H, 13C, 31P, and 29Si
NMR and electrospray mass spectra of the ferrocenyl deriva-
tives, and cyclic voltammogram of the functional biferrocene
derivative 20. This material is available free of charge via the
Internet at http://pubs.acs.org.
1H NMR (300 MHz, CDCl3) δppm: 3.62 (s, 6H, CH3CO2Cp),
4.19 (m, 8H, CH of Fv), 4.36 (m, 4H, CH of CpCO2CH3), 4.59
(m, 4H, CH of CpCO2CH3).
13C NMR (75 MHz, CDCl3) δppm: 51.5 (CH3CO2Cp), 67.5,
69.5, 71.1, 72.2 (CH of Fv and CpCO2CH3), 83.9 (Cq of Fv),
171.2 (CO2CH3).
(53) Diallo, A. K.; Daran, J.-C.; Varret, F.; Ruiz, J.; Astruc, D. Angew.
Chem., Int. Ed. 2009, 48, 3141–3145.
(54) (a) Ruiz, J.; Astruc, D. C. R. Acad. Sci. Paris, t. 1, Seꢀrie II c 1998, 21–
27. (b) Ruiz, J.; Daniel, M.-C.; Astruc, D. Can. J. Chem. 2006, 84, 288–
299.
(51) Kovar, R. F.; Rausch, M. D. J. Organomet. Chem. 1972, 35, 351–366.
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