Heterobi- to heterotetrametallic transition metal complexes constructed from ferrocenecarboxylate and [{[Ti](μ-σ,π-C{triple bond, long}CSiMe3)2}M]+ units

Article abstract of DOI:10.1016/j.jorganchem.2007.06.059

A series of copper(I) and silver(I) carboxylates received from various ferrocenecarboxylic acids was synthesized and used in the preparation of heterooligometallic Ti-Cu(Ag)-Fe complexes. The silver(I) salts [FcCO₂Ag] (2a) and [FcCH{double bond, long}CHCO₂Ag] (2b) (Fc = ferrocenyl, (η⁵-C₅H₄)Fe(η⁵-C₅H₅)) were obtained through deprotonation of the respective acids FcCO₂H (1a) and FcCH{double bond, long}CHCO₂H (1b) with NEt₃, followed by a reaction with [AgNO₃]. The heterotrimetallic complexes {[Ti](μ-σ,π-C{triple bond, long}CSiMe₃)₂}AgO₂CFc (4a) and {[Ti](μ-σ,π-C{triple bond, long}CSiMe₃)₂}AgO₂CCH{double bond, long}CHFc (4b), where [Ti] denotes the (η⁵-C₅H₄SiMe₃)₂Ti unit, were obtained from the reaction of 2a and 2b with the organometallic π-tweezer compound [Ti](C{triple bond, long}CSiMe₃)₂ (3). The related heterotrimetallic copper(I) complex {[Ti](μ-σ,π-C{triple bond, long}CSiMe₃)₂}CuO₂CFc (9a) was prepared via two synthetic routes. First, salt 2a was reacted with [(η²-Me₃SiC{triple bond, long}CSiMe₃)CuBr]₂ (10) to give the alkyne-stabilized copper(I) carboxylate [(η²-Me₃SiC{triple bond, long}CSiMe₃)(CuO₂CFc)₂]₂ (11). Subsequent reaction of 11 with four equivalents of 3 afforded 9a. Alternatively, 9a and its analogues {[Ti](μ-σ,π-C{triple bond, long}CSiMe₃)₂}CuO₂C-E-Fc (E = trans-CH{double bond, long}CH (9b), CH₂CH₂ (9c)), were prepared from acidolysis of the Cu-C_Me bond in {[Ti](μ-σ,π-C{triple bond, long}CSiMe₃)₂}CuMe (8) with acids 1a-1c. An analogous reaction between HO₂CfcPPh₂M(CO)₅ (M = Cr (14a), Mo (14b), W (14c); fc = ferrocene-1,1′-diyl) and 8 at-30 °C gave the alkyne/ferrocene-bridged heterotetrametallic compounds {[Ti](μ-σ,π-C{triple bond, long}CSiMe₃)₂}CuO₂CfcPPh₂M(CO)₅ (M = Cr (15a), Mo (15b), W (15c)). Reversing the reaction steps so that {[Ti](μ-σ,π-C{triple bond, long}CSiMe₃)₂}CuO₂CfcPPh₂ (12) was prepared first and then reacted with M(CO)₅(thf) (M = Cr (13a), Mo (13b), W (13a)) gave complicated reaction mixtures from which pure 15a-15c could not be isolated. The solid-state structures of 5, 7, 9a, and 11 have been corroborated by single-crystal X-ray structural studies and the electrochemical behavior of acids 1a-1c and of complexes 4a, 4b and 9a-9c was studied by cyclic voltammetry.

Full text of DOI:10.1016/j.jorganchem.2007.06.059

Journal of Organometallic Chemistry 692 (2007) 4303–4314
www.elsevier.com/locate/jorganchem
Heterobi- to heterotetrametallic transition metal complexes
constructed from ferrocenecarboxylate
and [{[Ti](l-r,p-C„CSiMe3)2}M]+ units
a
b
a
a
Janett Kuhnert , Martin Lamacˇ , Tobias Ruffer , Bernhard Walfort ,
¨
¨
b
a,
*
ˇ
Petr Steˇpnicˇka , Heinrich Lang
a
Technische Universita¨t Chemnitz, Fakulta¨t fu¨r Naturwissenschaften, Institut fu¨r Chemie, Lehrstuhl fu¨r Anorganische Chemie,
Straße der Nationen 62, 09111 Chemnitz, Germany
Charles University, Faculty of Science, Department of Inorganic Chemistry, Hlavova 2030, 12840 Prague 2, Czech Republic
b
Received 11 April 2007; received in revised form 20 June 2007; accepted 28 June 2007
Available online 4 July 2007
Abstract
A series of copper(I) and silver(I) carboxylates received from various ferrocenecarboxylic acids was synthesized and used in the prep-
aration of heterooligometallic Ti–Cu(Ag)–Fe complexes. The silver(I) salts [FcCO2Ag] (2a) and [FcCH@CHCO2Ag] (2b) (Fc = ferroce-
nyl, (g5-C5H4)Fe(g5-C5H5)) were obtained through deprotonation of the respective acids FcCO2H (1a) and FcCH@CHCO2H (1b) with
NEt3, followed by a reaction with [AgNO3]. The heterotrimetallic complexes {[Ti](l-r,p-C„CSiMe3)2}AgO2CFc (4a) and {[Ti](l-r,
p-C„CSiMe3)2}AgO2CCH@CHFc (4b), where [Ti] denotes the (g5-C5H4SiMe3)2Ti unit, were obtained from the reaction of 2a and
2b with the organometallic p-tweezer compound [Ti](C„CSiMe3)2 (3). The related heterotrimetallic copper(I) complex {[Ti](l-r,
p-C„CSiMe3)2}CuO2CFc (9a) was prepared via two synthetic routes. First, salt 2a was reacted with [(g2-Me3SiC„CSiMe3)CuBr]2
(10) to give the alkyne-stabilized copper(I) carboxylate [(g2-Me3SiC„CSiMe3)(CuO2CFc)2]2 (11). Subsequent reaction of 11 with four
equivalents of 3 afforded 9a. Alternatively, 9a and its analogues {[Ti](l-r,p-C„CSiMe3)2}CuO2C–E–Fc (E = trans-CH@CH (9b),
CH2CH2 (9c)), were prepared from acidolysis of the Cu–CMe bond in {[Ti](l-r,p-C„CSiMe3)2}CuMe (8) with acids 1a–1c. An analo-
gous reaction between HO2CfcPPh2M(CO)5 (M = Cr (14a), Mo (14b), W (14c); fc = ferrocene-1,10-diyl) and 8 atꢀ30 ꢀC gave the alkyne/
ferrocene-bridged heterotetrametallic compounds {[Ti](l-r,p-C„CSiMe3)2}CuO2CfcPPh2M(CO)5 (M = Cr (15a), Mo (15b), W (15c)).
Reversing the reaction steps so that {[Ti](l-r,p-C„CSiMe3)2}CuO2CfcPPh2 (12) was prepared first and then reacted with M(CO)5(thf)
(M = Cr (13a), Mo (13b), W (13a)) gave complicated reaction mixtures from which pure 15a–15c could not be isolated. The solid-state
structures of 5, 7, 9a, and 11 have been corroborated by single-crystal X-ray structural studies and the electrochemical behavior of acids
1a–1c and of complexes 4a, 4b and 9a–9c was studied by cyclic voltammetry.
ꢁ 2007 Elsevier B.V. All rights reserved.
Keywords: Ferrocenecarboxylic acids; Organometallic p-tweezers; Titanium; Silver; Copper; Group-6 metal carbonyls; X-ray structure; Cyclic
voltammetry
1. Introduction
includes the construction of large complex molecules by
connecting independent building blocks. Prerequisites of
the successful application of this approach are the avail-
ability of suitable structural fragments and synthetic meth-
ods for their assembly. Recently, it has been shown that
this approach can also be applied toward the preparation
of heteromultinuclear transition metal complexes [4].
Compounds thus prepared offer the possibility to study
The concept of molecular ‘‘tinkertoys’’ described by
Michl and co-workers [1], or ‘‘Legoꢂ’’ approach intro-
duced [2] and developed by Raymo and Stoddart [3]
*
Corresponding author. Tel.: +49 371 531 1673; fax: +49 371 531 1833.
E-mail address: heinrich.lang@chemie.tu-chemnitz.de (H. Lang).
0022-328X/$ - see front matter ꢁ 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2007.06.059

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J. Ku¨hnert et al. / Journal of Organometallic Chemistry 692 (2007) 4303–4314
electronic communication between different redox-active
metal atoms in oligometallic molecules and may act as cat-
alytically active systems for homogeneous catalysis, provid-
ing cooperative effects due to the presence of additional
metal centers [5].
We report here about the synthesis of copper(I) and sil-
ver(I) carboxylates with several ferrocenecarboxylic acids
and their use in the preparation of heterooligometallic
complexes with organometallic p-tweezer precursors. Fur-
thermore, in the case of 10-(diphenylphosphanyl)-1-ferro-
cenecarboxylic acid (Hdpf) [6], we made use of the
coordination ability of the phosphanyl group toward differ-
ent transition metal fragments to synthesize complexes of
higher nuclearity. The advantage of the ferrocene back-
bone is seen not only in its synthetic versatility and robust-
Whereas heterotrimetallic 4a and 4b dissolve well in
common organic solvents the silver(I) salts 2a and 2b are
practically insoluble. Hence, the silver(I) salts could be
characterized only by elemental analysis and IR spectros-
copy. The more soluble complexes 4a and 4b have been
characterized similarly and also by multinuclear NMR
spectroscopy. IR spectra of 4a and 4b show the character-
istic C„C stretching vibrations of the Ti–C„C–Si units
which are observed at 1948 (4a) and 1942 cmꢀ1 (4b),
respectively, which are shifted to lower wave-numbers as
compared with free 3 [8]. Similar observations have been
made for titanium–silver heterobimetallic p-tweezers, such
as {[Ti](l-r,p-C„CSiMe3)2}AgOSO2CF3 [8].
The NMR properties of these compounds correspond with
1
their formulated structures. The H NMR spectra of 4a–4b
ness, but also as
electrochemical properties of the resulting heterodi-, -tri-
and -tetrametallic complexes are discussed as well.
a
redox probe. The observed
are in accordance with the proposed formulation, displaying
signals due to the titanocene tweezer and the ferrocene
moieties. In13C{1H}NMR spectra, the alkynyl carbon atoms
Ca and Cb give rise to doublets due to coupling with the
embedded silver(I) ion (4a: Ca: dC 155.4, JAgC = 15 Hz; Cb:
dC 138.3, JAgC = 6 Hz; 4b: Ca: dC 156.0, JAgC = 15 Hz; Cb:
dC 137.4, JAgC = 7 Hz). Any further splitting resulting from
the occurrence of isotopomers containing the silver isotopes
107Ag and 109Ag (both I = 1/2, 107Ag 51.8%, 109Ag 48.2%)
[9] is not observed. Likewise, the 29Si{1H} NMR spectra of
4a and 4b show coupling for the C„CSiMe3 silicon atoms
with the silver(I) ions (JAgSi = 2 Hz).
Next we used the hybrid ferrocene phosphanylcarboxy-
lic acid Hdpf [6] as a starting material for the synthesis of
complexes of higher nuclearity as it offers the possibility
of extending the ferrocene-bridged assemblies via coordina-
tion of its phosphanyl functionality. Deprotonation of
Hdpf with triethylamine and reaction with [AgNO3] in eth-
anol leads to the tetrameric silver(I) salt [Ag(dpf)]4 (5).
Unfortunately, all attempts to react 5 with the p-tweezer
molecule 3 to give 6 have been unsuccessful (Scheme 2);
only a mixture of non-separable products was obtained.
Using a diethyl ether–ethanol mixture of 6:1 as a solvent
in the reaction of Hdpf with NEt3/[AgNO3] instead of pure
ethanol leads to [Ag(dpf)(Hdpf)] (7) (Scheme 2), probably
because of incomplete deprotonation of the carboxyl func-
tion by triethylamine in the mixed solvent.
2. Results and discussion
2.1. Syntheses and characterization of Ag(I) complexes
Heterotrimetallic Ti–Ag–Fe complexes of type {[Ti]-
(l-r,p-C„CSiMe3)2}AgO2CFc (4a) and {[Ti](l-r,
p-C„CSiMe3)2}AgO2CCH@CHFc (4b) (Fc = ferrocenyl,
fc = ferrocene-1,10-diyl) are accessible in a two-step proce-
dure from FcCO2H (1a) and FcCH@CHCO2H (1b),
respectively, as outlined in Scheme 1. The starting silver(I)
salts [FcCO2Ag] (2a) and [FcCH@CHCO2Ag] (2b) were
prepared by the reaction of the respective ferrocene carbox-
ylic acids, FcCO2H (1a) and FcCH@CHCO2H (1b), with
[AgNO3] in the presence of triethylamine in ethanol at
25 ꢀC [7]. However, attempts to prepare the analogous
silver(I) system from 3-ferrocenylpropionic acid (FcCH2-
CH2CO2H, 1c) under similar reaction conditions failed.
On addition of FcCH2CH2CO2ꢀNEt3H+ to a [AgNO3]-
containing ethanol solution the color immediately changed
to green indicating that most likely the ferrocene moiety
was oxidized. None the less, the appropriate ferrocenium
system could not be isolated, due to rapid decomposition.
This different behavior results from a higher electron den-
sity at iron which makes the Fc unit easier to oxidize (for
comparison see Table 2).
The NMR spectral properties of 5 and 7 correlate with
1
their formulated structures. In the H NMR of 5 and 7
Complexes 4a and 4b resulted from combining the
respective silver salts 2a and 2b with the organometallic
p-tweezer [Ti](C„CSiMe3)2 (3; [Ti] = (g5-C5H4SiMe3)2Ti)
at the molar ratio of 1:1 in tetrahydrofuran at 25 ꢀC.
the cyclopentadienyl protons give rise to four signals
between dH 4.04 and 4.85, the pattern being slightly differ-
ent for the two compounds. The 13C{1H} NMR signal of
the carbonyl carbon is found at dC 171.8 for 5 and at dC
SiMe3
C
C
[Ti]
AgOC(O)
E
AgOC(O)
E
HO2C
E
≡
3
( )
[AgNO3]
NEt3
[Ti](C CSiMe3)2
C
Fe
Fe
Fe
C
SiMe3
1a
1b
2a
: E = none
2b
: E = trans-CH=CH
: E = none
: E = trans-CH=CH
4a
4b
: E = none
: E =
trans-CH=CH
Scheme 1. Synthesis of 4a and 4b.

J. Ku¨hnert et al. / Journal of Organometallic Chemistry 692 (2007) 4303–4314
4305
SiMe3
C
C
[Ti]
(O)COAg
PPh2
AgOC(O)
≡
3
( )
[Ti](C CSiMe3)2
C
Fe
Fe
C
PPh2
[AgNO3]
NEt3
SiMe3
4
EtOH
5
6
CO2H
PPh2
Fe
[AgNO3]
NEt3
Hdpf
O
O
HO
Et2O/EtOH
6 : 1
C
P
C
O
Fe
Fe
Ag
P
Ph2
Ph2
7
Scheme 2. Synthesis of compounds 5 and 7 from Hdpf and [AgNO3], respectively.
178.2 for 7. The 31P{1H} NMR signals of 5 and 7 are split
into a pair of doublets due to the presence of the silver iso-
topes 107Ag and 109Ag (vide supra). Complex 5 resonates at
2.2. Syntheses and characterization of Cu(I) complexes
Trimetallic Ti–Cu–Fe complexes of structural type
{[Ti](l-r,p-C„CSiMe3)2}CuO2C–E–Fc (E = none (9a),
trans-CH@CH (9b), and CH2CH2 (9c)) were obtained from
the reaction of {[Ti](l-r,p-C„CSiMe3)2}CuMe (8) with
the appropriate acid in equimolar amounts at ꢀ30 ꢀC.
The reaction proceeds under H+ transfer and loss of CH4
to afford the heterotrimetallic complexes 9a–9c in virtually
quantitative yields (Eq. (1)).
1
1
dP 5.1 with J109Ag31P = 790 Hz and J107Ag31P = 669 Hz,
while the signal of 7 occurs at dP ꢀ1.8 with coupling con-
1
1
stants J109Ag31P = 526 Hz and J107Ag31P = 456 Hz. This
difference can be attributed to the different structures of
the complexes.
SiMe3
SiMe3
C
C
C
C
[Ti]
[Ti]
Cu CH3 + HO2C
SiMe3
E
CuOC(O)
SiMe3
E
-CH4
C
C
Fe
Fe
C
C
ð1Þ
8
none
1a:E =
1b:E =
1c:E =
9a
:E = none
9b
:E = trans
9c
:E = CH2CH2
trans-CH=CH
CH CH
-
CH=CH
2
2
Me3Si
Me3Si
SiMe3
CO2Ag
η2
≡
Cu
Cu
Cu
Cu
C
C
C
2 [( -Me3SiC CSiMe3)CuBr]2 (10)
4
Fe
≡
-2 Me3SiC CSiMe3
C
-4 AgBr
SiMe3
2a
11
Fe
O
=
SiMe3
C
C
C
O
C
C
[Ti]
4
CuOC(O)
≡
4 [Ti](C CSiMe3)2 (3)
Fe
≡
-2 Me3SiC CSiMe3
SiMe3
9a
Scheme 3. Synthesis of 9a via copper(I) carboxylate 11.

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J. Ku¨hnert et al. / Journal of Organometallic Chemistry 692 (2007) 4303–4314
SiMe3
C
C
[Ti]
CuOC(O)
C
Fe
C
M(CO)5(thf)
(13a - 13c)
≡
PPh2
{[Ti](C CSiMe3)2}CuCH3
SiMe3
(8)
SiMe3
CuOC(O)
SiMe3
-CH4
12
C
C
C
C
CO2H
PPh2
[Ti]
Fe
Fe
M(CO)5
P
Ph2
≡
{[Ti](C CSiMe3)2}CuCH3
15a:M=Cr
15b:M=Mo
15c
(8)
M(CO)5(thf)
-CH4
:M=W
CO2H
Fe
M(CO)5
P
Ph2
14a
14b
14c
:M=Cr
:M=Mo
:M=W
Scheme 4. Synthesis of heterotetrametallic complexes 15a–15c.
An alternative synthesis procedure leading to 9a is out-
lined in Scheme 3. The silver(I) salt 2a is treated first with
the dicopper(I) complex [(g2-Me3SiC„CSiMe3)CuBr]2
(10) [8b] at the molar ratio of 2:1 in tetrahydrofuran at
0 ꢀC to give the tetranuclear alkyne-stabilized copper(I)
carboxylate [(g2-Me3SiC„CSiMe3)(CuO2CFc)2]2 (11). In
a subsequent reaction with four equivalents of the p-twee-
zer 3, compound 11 gives the Ti–Cu–Fe molecule 9a as an
orange solid in 87% yield after appropriate work-up.
Reacting Hdpf with 8 under reaction conditions similar
to the synthesis of 9a–9c (vide supra) gave heterotrimetallic
{[Ti](l-r,p-C„CSiMe3)2}CuO2CfcPPh2 (12) which pos-
sesses a terminal phosphane group (Scheme 4). Unfortu-
nately, compound 12 is rather unstable, especially in
solution. It becomes very easily oxidized at the phosphorus
atom very likely because the presence of the p-tweezer
moiety increases the electron density at the PPh2 group.
Treatment of 12 with equimolar amounts of M(CO)5(thf)
(M = Cr (13a), Mo (13b), W (13c)) [10] gave only small
amounts of the desired Ti–Cu–Fe–M complexes 15a–15c
(Scheme 4) that could not be isolated in pure form either
by crystallization or column chromatography from the
obtained reaction mixtures. On the other hand, reacting
pre-formed HdpfM(CO)5 (M = Cr (14a), Mo (14b), W
(14c)) [11] with 8 in a 1:1 molar ratio gave the expected
heterotetrametallic complexes {[Ti](l-r,p-C„CSiMe3)2}-
CuO2CfcPPh2M(CO)5 (M = Cr (15a), Mo (15b), W (15c);
Scheme 4). However, owing to the considerable instability
of 15a–15c, even in solid state, only 15b could be isolated
in purity sufficient for spectroscopically characterization.
In an attempt to prepare a Ti–Cu–Fe–Ru compound
with the free phosphorus atom in 12 coordinating to
Ru(g6-1,4-MeC6H4(CHMe2))Cl2 we reacted [RuCl2(g6-
1,4-MeC6H4(CHMe2))]2 [12] with 12 and, alternatively,
also 8 with RuCl2(Hdpf)(g6-1,4-MeC6H4(CHMe2)) [13].
In both cases the work-up gave exclusively the known
CuCl-tweezer complex {[Ti](l-r,p-C„CSiMe3)2}CuCl
(16) [8]. The product 16 resulting via chloride transfer from
the ruthenium dichloride species to copper is apparently
thermodynamically more stable than the anticipated het-
erotetrametallic complex. The observed reaction behavior
parallels that reported for the reaction between, i.e.
[Ti](C„C-1-C6H4-4-C„N-4)2 and various [CuX] sources
(X = Cl, I), where only heterobimetallic p-tweezer com-
plexes {[Ti](l-r,p-C„CC6H4C„N-4)2}CuX have been
isolated [14].
Complexes 9a–9c, 11, and 12 were characterized by ele-
mental analysis, IR and NMR spectroscopy. Unfortu-
nately, due to the instability of 15a–15c, even in the solid
state, it was possible to record complete NMR data only
for 15b. All complexes show C„C stretching vibrations
at ca. 1915 cmꢀ1. The NMR spectroscopic properties of
these copper(I) complexes confirm their proposed struc-
tures. In the 1H NMR spectra of all copper(I) compounds,
the signals due to the ferrocene cyclopentadienyls are
observed in the range from dP 4.00 to 4.66. The signals of
the Me3Si groups are found as one or two singlets in the
range dP 0.20–0.26 (9a–9c, 12, 15b) or at dP 0.43 (11). In
the 13C{1H} NMR spectra of 15b one doublet is observed
for the equatorial CO ligands at dC 206.0 Hz (2JPC = 9 Hz).
However, the signal for the axial CO could not be detected.
The product resulting by complexation of Hdpf with the p-
tweezer molecule 8 did not exert a significant 31P{1H}
NMR coordination shift (cf. dP ꢀ19.1 for Hdpf and
ꢀ17.9 for 12). Nevertheless, when M(CO)5 units are intro-
duced as in 15a–15c, a remarkable shift is observed (cf. dP
ꢀ17.9 (12) to 45.6 (15a), 26.7 (15b), and 9.5 (15c)), corre-
sponding to dP values reported for the series of
(Hdpf)M(CO)5 complexes (cf. dP 46.0 (Cr), 26.6 (Mo),
and 9.3 (W)) [11].

J. Ku¨hnert et al. / Journal of Organometallic Chemistry 692 (2007) 4303–4314
4307
2.3. X-ray structure analysis
tal X-ray structure analysis. Relevant crystallographic and
structure refinement data are summarized in Table 3.
Complex 5 crystallizes in the tetragonal space-group
P42/n. Its tetrameric nature gives rise to a highly symmetric
though distorted heterocubane core Ag4O4 (Fig. 2) symmet-
rically surrounded by the bidentated ferrocene phosphanyl-
carboxylato moieties (Fig. 1). A distorted tetrahedral
coordination geometry is built around each silver ion by
one phosphorus and three oxygen atoms (P1–Ag1–O1B,
The solid state structures of 5 (Figs. 1 and 2), 7 (Fig. 3),
9a (Fig. 4), and 11 (Fig. 5) were established by single-crys-
Fig. 1. ORTEP plot (50% probability level) of 5 with the atom numbering
scheme (the hydrogen atoms, two non-coordinating CH2Cl2 molecules and
the phenyl ring carbons are omitted for clarity). Atoms generated by the
crystallographic symmetry operations (ꢀx + 1/2, ꢀy + 1/2, z) (A),
(y, ꢀx + 1/2, ꢀz + 1/2) (B), (ꢀy + 1/2, x, ꢀz + 1/2) (C) are distinguished
Fig. 3. ORTEP plot (50% probability level) of 7 with the atom numbering
scheme (the hydrogen atoms (except H2A) and one non-coordinating
CH2Cl2 molecule are omitted for clarity). Atoms generated by the
crystallographic (ꢀx + 4, ꢀy + 2, z) symmetry operation are distinguished
˚
with the suffixes A, B, and C. Selected bond distances (A) and angles (ꢀ):
˚
C11–O1, 1.290(6); C11–O2, 1.226(6); Ag1–P1, 2.3501(12); Ag1–O1,
2.535(3); Ag1–O1A, 2.291(3); Ag1–O1B, 2.448(3); Ag1A–O1, 2.291(3);
Ag1C–O1, 2.448(3); Fe1–D1, 1.643(2); Fe1–D2, 1.656(2); O1A–Ag1–P1,
149.98(9); O1A–Ag1–O1B, 82.10(12); P1–Ag1–O1B, 123.96(8);
O1A–Ag1–O1, 77.93(11); P–Ag1–O1, 119.15(8); O1B–Ag1–O1,
73.33(11); (D1 = centroid of C5H4PPh2, D2 = centroid of C5H4CO2).
with the suffix A. Selected bond distances (A) and angles (ꢀ): Ag1–O1,
2.4258(16); Ag1–O1A, 2.4258(16); Ag1–P1, 2.4283(5); Ag1–P1A,
2.4283(5); C23–O1, 1.238(3); C23–O2, 1.288(3); O2–O2A, 2.449(3);
Fe1–D1, 1.6512(14); Fe2–D2, 1.6518(13) (D1 = centroid of C5H4CO2,
D2 = centroid of C5H4PPh2); O1A–Ag1–O1, 79.69(9); O1A–Ag1–P1,
106.60(4); O1–Ag1–P1A, 106.60(4); O1A–Ag1–P1A, 107.41(4);
O1–Ag1–P1, 107.41(4); P1A–Ag1–P1, 135.21 (3); C23–O1–Ag1,
121.33(15); O1–C23–O2, 124.3(2).
Fig. 2. A view of the silver–oxygen heterocubane core in complex 5.
Fig. 4. ORTEP diagram (30% probability level) of 9a with the atom
Displacement ellipsoids correspond to 50% probability.
numbering scheme (the hydrogen atoms are omitted for clarity).

4308
J. Ku¨hnert et al. / Journal of Organometallic Chemistry 692 (2007) 4303–4314
Table 1
˚
A comparison of bond distances (A) and angles (ꢀ) in symmetrically
independent molecules of 9a
9aA (with Cu1)
9aB (with Cu2)
˚
Bond distances (A)
Fe1–D1a
Fe1–D2
C27–O1
C27–O2
1.633(3)
1.661(6)
1.269(7)
1.242(7)
1.936(4)
2.070(6)
2.128(6)
2.074(6)
2.133(6)
1.237(8)
1.240(8)
2.108(6)
2.093(6)
2.041(4)
2.043(3)
1.867(6)
1.850(7)
Fe2–D3
Fe2–D4
C64–O3
C64–O4
Cu2–O3
Cu2–C59
Cu2–C60
Cu2–C54
Cu2–C55
C59–C60
C54–C55
Ti2–C59
Ti2–C54
Ti2–D7
1.635(3)
1.656(6)
1.278(7)
1.235(6)
1.927(4)
2.072(6)
2.117(6)
2.071(6)
2.126(6)
1.242(8)
1.241(8)
2.100(6)
2.091(6)
2.042(4)
2.042(3)
2.9644(13)
Cu1–O1
Cu1–C17
Cu1–C18
Cu1–C22
Cu1–C23
C17–C18
C22–C23
Ti1–C17
Ti1–C22
Ti1–D5
Ti1–D6
C23–Si3
C18–Si4
Ti2–D8
Cu1–Ti
Bond angles (ꢀ)
Ti1–C17–C18
Ti1–C22–C23
C17–C18–Si4
C22–C23–Si3
C27–O1–Cu1
C17–Ti1–C22
C17–C18–Si4
a
Fig. 5. ORTEP diagram (50% probability) of 11 with the atom numbering
scheme (hydrogen atoms and methyl groups are omitted for clarity).
Symmetry generated atoms are named with the suffix A and generated by
165.8(5)
Ti2–C59–C60
Ti2–C54–C55
C59–C60–Si8
C54–C55–Si7
C64–O3–Cu2
C59–Ti2–C54
C22–C23–Si3
165.4(5)
166.1(5)
165.3(5)
161.1(5)
117.1(4)
88.7(2)
166.1(5)
164.7(5)
160.7(5)
117.1(4)
88.6(2)
˚
the (ꢀx + 1, ꢀy + 2, ꢀz + 1) operation. Selected bond distances (A) and
angles (ꢀ): C23–C24, 1.274(2); C22–O2, 1.252(2); C22–O3, 1.246(2);
C11–O1, 1.250(2); C11–O4, 1.247(2); Cu1–C23, 2.0033(18); Cu1–C24,
1.9972(19); Cu2–C23, 1.9941(18); Cu2–C24, 1.9880(17); Fe1–D1,
1.6503(12); Fe1–D2, 1.6571(13); Fe1–D3, 1.6394(12); Fe1–D4, 1.641(2);
Cu1–O1, 1.9414(15); Cu1–O3A, 1.9491(15); Cu2–O2, 1.9531(13);
Cu2–O4A, 1.9388(15); Cu1–Cu2, 2.9770(10); Cu1–Cu2A, 3.0754(11);
Si1–C23–C24, 160.56(16); Si2–C24–C23, 157.74(16); O1–Cu1–O3A,
102.62(7); O1–Cu1–C24, 145.72(7), O1–Cu1–C23, 111.84(7); O3A–Cu1–
C23, 142.64(7), C24–Cu1–C23, 37.14(7); C24–Cu2–C23, 37.32(7). Defini-
tions: D1, D3 = centroids of C5H4, D2, D4 = centroids of C5H5.
165.3(5)
161.1(5)
D1, D3 = centroids of C5H4CO2; D2, D4 = centroids of C5H5; D5,
D6, D7, D8 = centroids of the C5H4SiMe3 units.
atoms show some angular deformation attributable to ste-
ric congestion at the edge accommodating the bulky phos-
phane units (O1A–Ag1–O1, 79.69(9)ꢀ; O1A–Ag1–P1,
106.60(4)ꢀ; O1–Ag1–P1A, 106.60(4)ꢀ; O1A–Ag1–P1A,
107.41(4)ꢀ; O1–Ag1–P1, 107.41(4)ꢀ; P1A–Ag1–P1, 135.21
(3)ꢀ). In contrast to 5 the tilting of the cyclopentadienyl
rings is 2.59(18)ꢀ and they are rotated 12.7ꢀ to each other.
Heterotrimetallic 9a crystallizes in the triclinic space-
123.96(8)ꢀ; O1A–Ag1–O1, 77.93(11)ꢀ; P1–Ag1–O1B,
123.96(8)ꢀ). The oxygen atoms within the cube are part of
the carboxyl function attached to the ferrocene units, acting
˚
as l3-bridges (C11–O2, 1.226(6); C11–O1, 1.290(6) A).
Each O–Ag edge is spanned by the ferrocene moiety so that
the phosphanylcarboxylate donor binds to the silver(I) ion
ꢀ
group P1 with two independent molecules 9aA (with
˚
via its phosphorus atom (Ag1–P1, 2.3501(12) A). The ferro-
Cu1) and 9aB (with Cu2) in the asymmetric unit. The view
of the molecular solid-state structure of 9aA is shown in
Fig. 4. The individual molecules are very similar in bond
lengths and angles as well as in the overall molecular con-
formation (see Table 1).
cene cyclopentadienyl rings are rotated by ca. 4ꢀ to each
other which represents an almost eclipsed conformation
and show a tilting of only 3.1(3)ꢀ.
Orange crystals of 7 were obtained from a concentrated
dichloromethane solution at 0 ꢀC. Complex 7 crystallizes in
the tetrahedral space group I41, mimicking a twofold sym-
metry. The silver atom Ag1 is r-bonded to one oxygen
atom from both carboxyl functions and coordinated by
both phosphorus atoms (Ag1–O1, 2.4258(16); Ag1–P1,
In heterotrimetallic complex 9a the Cu1 is r-bonded to
O1 (cf. Cu1–O1, 1.936(4) A for 9aA) from the carboxylic
˚
function and further surrounded by two g2-coordinating
Ti–C„C–Si groups. All structural features of the organo-
metallic p-tweezer ligand are in accordance most common
to this type of early-late Ti–Cu complexes [8a,15]. The
cyclopentadienyl rings of the ferrocene moiety are rotated
by 24ꢀ in 9aA and by 21ꢀ in 9aB and show a tilting of
the cyclopentadienyl rings of 2.1(6)ꢀ in 9aA and 2.7(7)ꢀ in
9aB. These differences, however, are attributable to pack-
aging effects.
˚
2.4283(5) A). The hydroxyl group of the protonated car-
˚
boxyl function (C23–O1, 1.238(3); C23–O2, 1.288(3) A)
forms a hydrogen bridge to the carboxylate group
˚
(O2ꢁ ꢁ ꢁO2A, 2.449(3) A) which stabilizes the structure.
Due to the overall symmetry, the H2A atom is disordered
over two positions (as if bonded to O2 or O2A) with occu-
pancies fixed at 0.5. The tetrahedral environment around
the silver atom built from two oxygen and two phosphorus
Yellow crystals of 11 resulted from a slow diffusion of n-
pentane into a dichloromethane solution containing 11 at

J. Ku¨hnert et al. / Journal of Organometallic Chemistry 692 (2007) 4303–4314
4309
25 ꢀC. The compound crystallized as a non-stoichiometric
solvate with the solvent molecules disordered in structural
voids. The structural determination of 11 was rather com-
plicated, since some residual peaks occurred in the electron
density difference map. They correspond to solvent mole-
cules present in the crystals. The peaks could not be attrib-
uted to ordered molecules and it was judged preferable to
omit them from calculations by the use of the SQUEEZE
acids 1a–1c was studied by cyclic voltammetry at a plati-
num electrode in dichloromethane solutions (see Section
4 for more details). Pertinent electrochemical data are sum-
marized in Table 2; all potentials are given relative to that
of the ferrocene/ferrocenium couple [20].
As expected, acids 1a–1c undergo reversible one-elec-
tron oxidation of the ferrocene moiety to the correspond-
ing ferrocenium. Redox potential of the ferrocene/
ferrocenium couple decreases in the order 1a > 1b > 1c,
clearly reflecting the properties of the linker between the
ferrocene unit and the carboxyl group. The presence of a
two-carbon spacer group in 1b and 1c reduces the influence
of the carboxyl group (i) via increasing its distance of the
ferrocene unit and (ii) via compensating its electron-with-
drawing influence by own electronic-donor and electron-
relay properties. Consequently, the acid 1c possessing the
saturated bridge as the strongest electron donor and non-
conjugated insulating bridge is oxidized most easily, i.e.
at lowest potentials. In addition, the acids show broad,
ill-defined reduction waves between ꢀ1.47 and ꢀ1.61 V
attributable to the reduction of their carboxyl groups.
The redox behavior of tweezer 3 is also rather simple as
the compound undergoes a single reversible reduction at
ꢀ1.72 V [8,21]. The wave is attributable to the reversible
reduction of the Ti(IV) titanocene fragment and appears
shifted by 90 mV positively as compared with the value
obtained in an acetonitrile solution [21].
The redox response of the trimetallic complexes is much
more complex, allowing only for a semiqualitative discus-
sion. Thus, 4b undergoes reversible oxidation of the ferro-
cene moiety at 0.02 V, which is 160 mV more negative than
the redox process of 1b. The cathodic region of the cyclic
voltammogram shows an irreversible reduction wave at
ꢀ1.53 V and a reduction at ꢀ1.86 V (Table 2) that are
attributable to silver- and titanocene-centered reductions,
respectively. The reduction behavior of the non-spaced ana-
logue 4a is quite similar, though with the respective waves
occurring at ꢀ1.48 and ca. ꢀ1.81 V. The reduction poten-
tial of the process T(IV) + eꢀ ! Ti(III) is almost indepen-
dent of the chemical identity of the central ions in the
heterometallic complexes. They agree with the free organo-
metallic p-tweezer ligand. This is in agreement with the
suggested fragmentation occurring as a consequence after
reduction of the silver(I) or copper(I) (see below) metal
ions resulting in the same bis(alkynyl) titanocene system
in all cases [21]. In the anodic region, compound 4a shows
two oxidation waves: a reversible one at 0.00 V, due to the
ferrocene/ferrocenium couple followed by a broad and
smaller though reversible wave at ca. 0.26 V (Table 2).
The parallel series of copper(I) organometallic p-tweezer
complexes shows similar differences between the 1a-based
compound 9a on one hand and the ‘spaced’ complexes 9b
and 9c on the other. Compound 9a is oxidized in two suc-
cessive reversible steps at ꢀ0.02 and 0.25 V (Table 2). Like-
wise, the reduction occurs in two-step pattern similar to all
other compounds: an irreversible wave at ꢀ1.69 V due to
copper(I) and a irreversible wave at ꢀ1.92 V attributable
1
procedure in PLATON-94 [16,17]. However, from H NMR
studies of single crystals of 11 it could be shown that
dichloromethane and n-pentane are present in the crystal-
line material.
ꢀ
Complex 11 crystallizes in the triclinic space group P1. A
main characteristic feature of 11 is the paddle wheel-like, tet-
rameric arrangement of the four ferrocenyl moieties. Two
ferrocenecarboxylate building blocks form bridges between
a pair of copper(I) ions. The (FcCO2)2Cu2 units thus formed
are interconnected via a l-g2:g2-coordinated alkyne into a
symmetric tetramer showing Cuꢁ ꢁ ꢁCu separations of
˚
2.9770(10) (Cu1ꢁ ꢁ ꢁCu2) and 3.0754(11) A (Cu1ꢁ ꢁ ꢁCu2A)
(Cu1–C23, 2.0033(18); Cu1–C24, 1.9972(19); Cu2–C23,
2
˚
1.9941(18); Cu2–C24, 1.9880(17) A). In contrast to [(g -
Me3SiC„CSiMe3)(CuO2CH3)2]2 [18], the Cuꢁ ꢁ ꢁCu dis-
˚
tances in 11 mutually differ by ca. 0.1 A. However, other
structural features of the Cu–alkynyl unit are very similar
to those of the related (g2-alkyne)copper(I) complexes [19].
The cyclopentadienyl rings of the ferrocenyl moieties are
rotated by ca. 17ꢀ (Fe1) or 10ꢀ (Fe2) and show tilts of
2.89(15)ꢀ (Fe1) and 2.6(2)ꢀ (Fe2). The Fe1 atom exhibits sep-
˚
arations of 1.6503(12) and 1.6571(13) A to the ring centroids
˚
D1 and D2, while 1.6394(12) and 1.641(2) A are found for
Fe2 and centroids D3 and D4, respectively (D1, D3 = cent-
roids of the substituted cyclopentadienyl ring C5H4, D2,
D4 = centroids of the cyclopentadienyl ring C5H5).
2.4. Electrochemistry
The series involving heterotrimetallic complexes 4a–b,
9a–9c, the organometallic p-tweezer 3, and their parent
Table 2
Electrochemical data of 1a–1c, 3, 4a–4b, and 9a–9ca
Compound
Anodic region
Cathodic region
E1/2 (DE) (V (mV))
Epa (V)
1a
1b
1c
3
0.23 (80)
0.18 (75)
ꢀ0.01 (125)
ꢀ1.61
ꢀ1.54
ꢀ1.47
ꢀ1.72 (120)b
ꢀ1.48, ꢀ1.81
ꢀ1.53, ꢀ1.86
ꢀ1.69, ꢀ1.92
ꢀ1.73, ꢀ1.92
ꢀ1.70, ꢀ1.92
4a
4b
9a
9b
9c
a
0.00 (95), 0.26 (100)
0.02 (80)
ꢀ0.02 (75), 0.25 (105)
0.05 (90)
ꢀ0.03 (100)
Recorded on a platinum electrode in dichloromethane solutions
(0.5 mM analyte, 0.1 M [Bu4N][PF6]) at 100 mV/s. The potentials are
given relative to the ferrocene/ferrocenium reference [20]. Definitions:
half-wave potential E1/2 = 1/2(Epa + Epc), peak separation DE = Epa
Epc; Epa and Epc denote anodic and cathodic peaks, respectively.
ꢀ
b
Reversible reduction; given as: E1/2 (DE) (V (mV)).

4310
J. Ku¨hnert et al. / Journal of Organometallic Chemistry 692 (2007) 4303–4314
to the Ti(IV)/Ti(III) redox couple (vide supra) [21]. The
reduction of 9b and 9c occurs in a similar pattern and at
similar potentials as described for 9a. By contrast, how-
ever, the ‘spaced’ compounds undergo only single oxida-
tion within the experimentally accessible region. Again,
this difference of the oxidation potentials is in accordance
with the properties of the carboxylate part (vide supra).
prepared by dissolving the samples in dry dichloromethane
containing 0.1 M [Bu4N][PF6] (Fluka, dried under oil-
pump vacuum) as the supporting electrolyte to give
0.5 mM analyte solutions. Cyclic voltammograms were
recorded using a PGZ 100 instrument (Radiometer).
Melting points were determined using analytically pure
samples, sealed off in nitrogen purged capillaries on a Gal-
lenkamp MFB 595 010 M melting point apparatus. Micro-
analyses were performed by the Institute of Organic
Chemistry, Chemnitz, University of Technology (C,H,N-
Analysator of the company Foss Heraeus Vario) and
partly by the Institute of Inorganic Chemistry, University
of Halle (CHNS 932, Leco company).
FcCH@CHCO2H (1b) [22], FcCH2CH2CO2H (1c) [23],
[Ti](C„CSiMe3)2 (3) [24], {[Ti](l-r,p-C„CSiMe3)2}-
CuMe (8) [25], [{(g2-Me3SiC„CSiMe3)CuBr}2] (10) [18],
Hdpf [6], and M(CO)5(Hdpf) (14a–14c) [11] were prepared
according to published procedures. All other chemicals
were purchased from commercial suppliers and were used
without further purification.
3. Conclusion
Silver(I) and copper(I) ferrocenecarboxylates readily
form heterotrimetallic early-late complexes of structural
type {[Ti](l-r,p-C„CSiMe3)2}MO2C–E–Fc when com-
bined with [Ti](C„CSiMe3)2 titanocene p-tweezer mole-
cules (E = none, trans-CH@CH, CH2CH2; M = Ag, Cu;
[Ti] = (g5-C5H4SiMe3)2Ti). The use of 10-(diphenylphos-
phanyl)-1-ferrocenecarboxylic acid (Hdpf), which posses
an additional functionality, allows for an extension of this
molecular approach toward heterotetrametallic complexes
of type {[Ti](l-r,p-C„CSiMe3)2}CuO2CfcPPh2M(CO)5
(M = Cr, Mo, W).
4.2. Synthesis
4. Experimental
4.2.1. Synthesis of [FcCO2Ag] (2a)
4.1. General comments
Silver(I) nitrate (369 mg, 2.17 mmol) was dissolved in
0.25 mL of acetonitrile. 10 mL of ethanol was added. To
this reaction solution ferrocenecarboxylic acid (1a)
(500 mg, 2.17 mmol) and triethylamine (220 mg, 0.3 mL,
2.17 mmol) dissolved in 10 mL of ethanol were slowly
dropped. A yellow precipitate was immediately formed.
After stirring for 1 h at 25 ꢀC the yellow solid was filtered
off washed twice with 10 mL portions of ethanol and dried
in oil-pump vacuum. The silver(I) carboxylate 2a was
obtained as a yellow solid. Yield: 682 mg (2.03 mmol,
93% based on 1a).
All reactions were carried out under an atmosphere of
purified nitrogen (4.6) using standard Schlenk techniques.
Tetrahydrofuran and n-hexane were purified by distillation
from sodium/benzophenone ketyl; dichloromethane was
purified by distillation from calcium hydride. Ethanol
was purified by distillation from sodium/diethyl phthalate.
Triethylamine was purified by distillation from KOH. Ace-
tonitrile was purified by distillation from P2O5. Celite
(purified and annealed, Erg. B.6, Riedel de Haen) was used
for filtrations.
Mp. 100 ꢀC (dec.). IR (KBr, cmꢀ1): 3100 (w), 2962 (w),
2925 (w), 2853 (w), 1540 (vs) mas(CO), 1467 (s), 1388 (s),
1359 (m), 1344 (m), 1261 (m), 1183 (w), 1106 (m), 1059
(w) 1022 (m), 820 (m), 801 (m), 553 (w), 511 (w), 485 (w),
473 (w), 435 (w). Due to insolubility in common NMR-sol-
vents, no NMR spectra of 3 could be recorded. Anal. Calc.
for C11H9AgFeO2 (336.90): C, 39.20; H, 2.69. Found: C,
39.10; H, 3.01%.
Infrared spectra were recorded with a Perkin–Elmer FT-
IR spectrometer Spectrum 1000. H NMR spectra were
1
recorded with a Bruker Avance 250 spectrometer operating
at 250.130 MHz in the Fourier transform mode; 13C{1H}
NMR spectra were recorded at 62.860 MHz. Chemical
shifts are reported in d units (parts per million) downfield
from tetramethylsilane with the solvent as reference signal
(CDCl3: 1H NMR d = 7.26; 13C{1H} NMR d = 77.16).
31P{1H} NMR spectra were recorded at 101.255 MHz in
CDCl3 with P(OMe)3 as an external standard (d = 139.0
relative to 85% aqueous H3PO4 (d = 0.00)). 29Si{1H}
NMR spectra were recorded at 49.662 MHz in CDCl3 with
tetramethylsilane as an external standard (d = 0.0). All
NMR experiments were carried out at 298 K.
4.2.2. Synthesis of [FcCH@CHCO2Ag] (2b)
FcCH@CHCO2H (1b) (215 mg, 0.78 mmol) and trieth-
ylamine (0.3 mL, 2.17 mmol) dissolved in 10 mL of ethanol
were slowly added to a stirred solution of [AgNO3]
(142 mg, 0.84 mmol) in acetonitrile (0.5 mL) at room tem-
perature.
A red-brown precipitate was immediately
Cyclic voltammograms were recorded in a dried cell
purged with purified argon. A platinum wire served as a
working electrode and as a counter electrode. A saturated
calomel electrode in a separated compartment served as
reference electrode. All electrode potentials given in the
text are given relative to the redox potential of the ferro-
cene/ferrocenium couple [20]. The analyzed solutions were
formed, and after 45 min of stirring, it was filtered off,
washed with 10 mL of ethanol and dried in oil-pump vac-
uum to afford 2b as a red-brown solid, insoluble in common
organic solvents. Yield: 279 mg (0.77 mmol, 99% based on
1b).
Mp. 120 ꢀC (dec.). IR (KBr, cmꢀ1): 1639 (s) m(C@C),
1562 (vs) mas(CO), 1400 (s), 1382 (s), 1286 (w), 1259 (w),

J. Ku¨hnert et al. / Journal of Organometallic Chemistry 692 (2007) 4303–4314
4311
1106 (w), 1046 (w), 1030 (w), 999 (w), 815 (w), 670 (w), 487
(w), 477 (w). Due to insolubility in common NMR-solvents
no NMR spectra of 2b could be recorded. Anal. Calc. for
C13H11AgFeO2 (362.92): C, 43.02; H, 3.06. Found: C,
42.72; H, 3.46%.
JAgC = 15 Hz, TiC„CSiMe3), 173.2 (COOH). 29Si{1H}
NMR (CDCl3): d ꢀ17.9 (d, JAgSi = 2 Hz, Me3SiC„C),
ꢀ5.7 (Me3SiC5H4). Anal. Calc. for C39H55AgFeO2Si4Ti
(879.75): C, 53.24; H, 6.30. Found: C, 53.19; H, 6.00%.
4.2.5. Synthesis of [Ag(dpf)]4 (5)
4.2.3. Synthesis of {[Ti](l-r,p-C„CSiMe3)2}AgO2CFc
(4a)
Silver(I) nitrate (160 mg, 0.94 mmol) was dissolved in
0.15 mL of acetonitrile and afterward 10 mL of ethanol
was added. To this solution Hdpf (390 mg, 0.94 mmol)
and triethylamine (119 mg, 0.15 mL, 1.08 mmol) in 10 mL
of ethanol were slowly added, whereby a yellow precipitate
immediately formed. After stirring for 1 h at 25 ꢀC the sol-
vent was reduced to a volume of 10 mL and the yellow
solid was filtered off washed twice with 5 mL portions of
ethanol and dried in oil-pump vacuum to gave yellow 5.
Yield: 318 mg (0.61 mmol, 65% based on Hdpf).
[Ti](C„CSiMe3)2 (3) (238 mg, 0.46 mmol) was dissolved
in 30 mL of tetrahydrofuran. To this solution [FcCO2Ag]
(2a) (155 mg, 0.46 mmol) was added in a single portion.
The reaction solution was allowed to stirr for 2 h at
25 ꢀC. Afterward it was filtered through a pad of Celite.
Removal of all volatiles in oil pump vacuum gave an orange
solid. Yield: 365 mg (0.427 mmol; 92.8% based on 2a).
Mp. 110 ꢀC. IR (KBr, cmꢀ1): 3058 (w), 2955 (w), 2896
(w), 1948 (w) m(C„C), 1570 (s) mas(CO), 1466 (s), 1408
(w), 1381 (s), 1339 (m), 1247 (s), 1176 (m), 1104 (w), 1048
(m), 1020 (w), 1001 (w), 902 (m), 841 (vs), 756 (s), 672
Mp. 181 ꢀC. IR (KBr, cmꢀ1): 1560 (vs) mas(CO), 1542
(vs), 1461 (m), 1436 (m), 1386 (s), 1350 (m), 1167 (m),
1093 (m), 1027 (m), 743(m), 694 (m), 503 (m), 465 (m),
441 (m), 418 (m). 1H NMR (CDCl3): d 4.05 (bs, 2H,
C5H4), 4.30 (bs, 2H, C5H4), 4.59 (bs, 2H, C5H4), 4.85 (bs,
2H, C5H4), 7.32–7.68 (m, 10H, Ph). 13C{1H} NMR
(CDCl3): d 70.6 (CH/C5H4), 72.6 (CH/C5H4), 72.7 (CH/
1
(s), 634 (w), 606(w), 505 (w). H NMR (CDCl3): d 0.24
(s, 18H, C„CSiMe3), 0.25 (s, 18H, C5H4SiMe3), 4.18 (pt,
JHH = 1.8 Hz, 2H, C5H4), 4.2 (s, 5H, C5H5), 4.71 (pt,
JHH = 1.8 Hz, 2H, C5H4), 6.22 (pt, JHH = 2.3 Hz, 4H,
C5H4SiMe3), 6.27 (pt, JHH = 2.3 Hz, 4H, C5H4SiMe3).
1
i
C5H4), 73.4 (CH/C5H4), 75.0 (d, JPC = 15 Hz, C/C5H4),
78.2 (iC/C5H4), 128.9 (d, JPC = 11.0 Hz, CH/Ph), 130.7
(CH/Ph), 133.8 (d, JPC = 16.8 Hz, CH/Ph), 171.8 (CO2),
13C{1H} NMR (CDCl3):
d
0.2 (C„CSiMe3), 0.5
(C5H4SiMe3), 69.1 (C5H5), 69.2(CH/C5H4), 70.5 (CH/
C5H4), 79.7 (iC/C5H4), 116.3 (C5H4SiMe3), 118.5(C5H4-
SiMe3), 124.4 (iC/C5H4SiMe3), 138.3 (d, JAgC = 6.2 Hz,
TiC„CSiMe3), 155.4 (d, JAgC = 15.4 Hz, TiC„CSiMe3),
175.8 (CO2). 29Si{1H} NMR (CDCl3): d ꢀ17.9 (d, JAgSi
= 2.8 Hz, C„CSiMe3), ꢀ5.7 (C5H4SiMe3). Anal. Calc.
for C37H53AgFeO2Si4Ti (853.72): C, 52.05; H, 6.26. Found:
C, 51.33, H, 6.20%.
i
the signal of C/Ph could not be detected. 31P{1H} NMR
1
(CDCl3):
d
5.1 (d, J109Ag31P = 790.0 Hz), 5.1 (d,
1J107Ag31P = 668.7 Hz). Anal. Calc. for C23H18AgFeO2P
(521.06): C, 53.01; H, 3.48. Found: C, 51.97; H, 3.69%.
4.2.6. Synthesis of [Ag(dpf)(Hdpf)] (7)
Using the same procedure and the same amounts of the
starting materials like for the preparation of 5, but running
the reaction in a mixture of Et2O/EtOH (6:1) gave 7 as a
yellow solid. Yield: 353 mg (0.38 mmol, 81% based on
Hdpf).
4.2.4. Synthesis of {[Ti](l-r,p-C„CSiMe3)2}-
AgO2CCH@CHFc (4b)
[Ti](C„CSiMe3)2 (3) (326 mg, 0.63 mmol) was dissolved
in 15 mL of tetrahydrofuran and [FcCH@CHCO2Ag] (2b)
(230 mg, 0.63 mmol) was added in one portion. The reac-
tion solution was stirred for 2 h at 25 ꢀC, while the color
changed from orange to red. Afterward it was filtered
through a pad of Celite. All volatiles were removed in oil
pump vacuum to gave 4b as a red-brown solid. Yield:
519 mg (0.59 mmol, 94% based on 2b).
Mp. 176 ꢀC. IR (KBr, cmꢀ1): 3351 (m) m(OH), 3053 (w),
2963 (w), 2859 (w), 1637 (s) mas(CO), 1561 (m), 1546 (m),
1479 (s), 1436 (s), 1383 (s), 1337 (m), 1310 (m), 1268 (w),
1199 (w), 1170 (s), 1096 (s), 1070 (w), 1052 (w), 1029 (s),
999 (w), 916 (w), 877 (w), 831 (m), 804 (m), 742 (s), 694
1
(s), 632 (w), 538 (w), 498 (s). H NMR (CDCl3): d 4.04
(pt, JHH = 1.9 Hz, 4H, C5H4), 4.53 (bs, 4H, C5H4), 4.62
(pt, JHH = 1.7 Hz, 4H, C5H4), 4.84 (pt, JHH = 1.9 Hz,
4H, C5H4), 7.20–7.53 (m, 24H, Ph). 13C{1H} NMR
(CDCl3): d 71.2 (C5H4), 73.0 (C5H4), 75.4 (C5H4), 76.4
(C5H4), 128.7 (m, Ph), 130.2 (Ph), 134.0 (m, Ph), 178.2
Mp. 99 ꢀC (dec.). IR (KBr, cmꢀ1): 2953 (m), 2896 (w),
1942 (w) m(C„C), 1637 (m) m(C@C), 1552 (s) mas(CO),
1400 (s), 1375 (s), 1246 (s), 1176 (w), 1045 (w), 902 (w),
1
840 (vs), 756 (m), 672 (s), 495 (w). H NMR (CDCl3): d
1
0.23 (s, 18H, SiMe3), 0.24 (s, 18H, SiMe3), 4.09 (s, 5H,
C5H5), 4.22 (pt, JHH = 1.8 Hz, 2H, C5H4), 4.42 (pt,
JHH = 1.8 Hz, 2H, C5H4), 6.23 (m, 8H, C5H4SiMe3), 6.26
(CO2). 31P{1H} NMR (CDCl3): d ꢀ1.8 (d, J109Ag31P
1
= 526.1 Hz), ꢀ1.8 (d, J107Ag31P = 455.9 Hz). Anal. Calc.
for C46H37AgFe2O4P2 (935.25): C, 59.07; H, 3.99. Found:
C, 58.73; H, 4.59%.
2
2
(d, JHH = 15.5 Hz, 1H, @CH), 7.27 (d, JHH = 15.5 Hz,
1H, @CH). 13C{1H} NMR (CDCl3): d 0.2 (CH3), 0.3
(CH3), 68.0 (CH/C5H4), 69.4 (C5H5), 69.5 (CH/C5H4),
81.4 (iC/C5H4), 116.7 (CH/C5H4SiMe3), 118.6 (CH/
C5H4SiMe3), 122.8 (@CH), 124.3 (iC/C5H4SiMe3), 137.4
(d, JAgC = 7 Hz, TiC„CSiMe3), 138.4 (@CH), 156.0 (d,
4.2.7. Synthesis of {[Ti](l-r,p-C„CSiMe3)2}-
CuO2CFc (9a)
Method 1: [(g2-Me3SiC„CSiMe3)(CuO2CFc)2]2 (11)
(37 mg, 0.02 mmol) was dissolved in 20 mL of tetrahydro-

4312
J. Ku¨hnert et al. / Journal of Organometallic Chemistry 692 (2007) 4303–4314
i
furan. [Ti](C„CSiMe3)2 (3) (41 mg, 0.08 mmol) was added
in a single portion at 25 ꢀC. The dark red solution was stir-
red for 1 h and was then evaporated to dryness in oil-pump
vacuum. The residue was washed twice with 5 mL portions
of n-hexane and dried in oil-pump vacuum. Complex 9a was
obtained as an orange solid. Yield: 57 mg (0.07 mmol, 87%
based on 11).
(TiC„CSiMe3), the signals for C/C5H4, 2· @CH, and
HO2C could not be detected. 29Si{1H} NMR (CDCl3): d
ꢀ15.5 (Me3SiC„C), ꢀ6.0 (Me3SiC5H4). Anal. Calc. for
C39H55CuFeO2Si4Ti (835.43): C, 56.07; H, 6.64. Found: C,
56.24; H, 6.54%.
4.2.9. Synthesis of {[Ti](l-r,p-C„CSiMe3)2}-
CuO2CCH2CH2Fc (9c)
Method 2: {[Ti](l-r,p-C„CSiMe3)2}CuMe (8) (85 mg,
0.14 mmol) was dissolved in 20 mL of tetrahydrofuran
and cooled to ꢀ30 ꢀC. To this solution FcCO2H (1a)
(33 mg, 0.14 mmol) in 5 mL of tetrahydrofuran was added
dropwise over a period of 5 min. The resulting solution was
stirred for 30 min at ꢀ30 ꢀC and then for 1 h at 25 ꢀC. The
solvent was evaporated in oil-pump vacuum and the residue
was extracted with n-hexane (15 mL) and filtered through a
pad of Celite. After evaporation of the solvent in oil-pump
vacuum, compound 9a was obtained as an orange solid.
Yield: 108 mg (0.13 mmol, 93% based on 1a).
FcCH2CH2CO2H (1c) (52 mg, 0.20 mmol) was reacted
with {[Ti](l-r,p-C„CSiMe3)2}CuMe (8) (120 mg, 0.20
mmol) under similar conditions as described for the synthe-
sis of 9b. After evaporation of the solvent, the residue was
extracted into 10 mL of n-hexane and filtered under nitro-
gen through a pad of Celite. Removal of the solvent in oil-
pump vacuum gave 9c as a red-brown waxy solid. Yield:
143 mg (0.17 mmol, 85% based on 1c).
IR (NaCl, cmꢀ1): 3094 (w), 2962 (s), 2927 (m), 2905
(m), 2856 (w), 1916 (w) m(C„C), 1716 (w) mas(CO),
1583–1557 (composite m) m(C@C), 1446 (w), 1410 (m),
1374 (w), 1260 (s), 1177 (w), 1104–1022 (composite s),
903 (w), 800 (composite s), 759 (m), 698 (m), 635 (w).
1H NMR (CDCl3): d 0.25 (s, 36H, CH3), 2.63 (m, 4H,
CH2), 4.03 (bs, 2H, C5H4), 4.09 (m, 7H, C5H4 and
C5H5), 6.00 (bs, 4H, C5H4SiMe3), 6.11 (bs, 4H,
C5H4SiMe3). 13C{1H} NMR (CDCl3): d 0.3 (CH3), 1.2
(CH3), 67.2 (CH/C5H4), 68.1 (CH/C5H4), 68.6 (C5H5),
89.2 (iC/C5H4), 113.6 (CH/C5H4SiMe3), 116.5 (CH/
C5H4SiMe3), 121.9 (iC/C5H4SiMe3), 132.8 (TiC„C-
SiMe3), 170.7 (TiC„CSiMe3), the signals of CH2 and
COOH could not be detected. 29Si{1H} NMR (CDCl3):
d ꢀ15.6 (Me3SiC„C), ꢀ6.0 (Me3SiC5H4). Anal. Calc.
for C39H57CuFeO2Si4Ti (837.45): C, 55.93; H, 6.86.
Found: C, 55.05; H, 7.54%.
Mp. 149 ꢀC (dec.). IR (KBr, cmꢀ1): 2953 (m), 2895 (w),
1915 (w) m(C„C), 1584 (s), mas(CO), 1458 (s), 1380 (s), 1331
(s), 1246 (s), 1176 (w), 1051 (w), 902 (w), 841 (vs), 757 (m),
1
681 (m). H NMR (CDCl3): d 0.24 (s, 18H, C„CSiMe3),
0.25 (s, 18 H,C5H4SiMe3), 4.19–4.21 (m, 7H, C5H4,
C5H5), 4.66 (pt, JHH = 1.7 Hz, 2H, C5H4), 6.01 (pt,
JHH = 2.3 Hz, 4H, C5H4SiMe3), 6.1 (pt, JHH = 2.3 Hz,
4H, C5H4SiMe3). 13C{1H} NMR (CDCl3): d 0.3 (CH3),
0.5 (CH3), 69.1 (C5H5), 69.2 (C5H4), 69.3 (C5H4), 69.3
(C5H4), 113.7 (CH/C5H4SiMe3), 116.5 (CH/C5H4SiMe3),
121.9 (iC/C5H4SiMe3), 133.5 (TiC„CSiMe3), 170.5
(TiC„CSiMe3). Please, notice that the HO2CH signal
could not be detected. 29Si{1H} NMR (CDCl3): d ꢀ15.4
(C„CSiMe3), ꢀ6.0 (C5H4SiMe3). Anal. Calc. for C37H53-
CuFeO2Si4Ti (809.39): C, 54.90; H, 6.60. Found: C, 54.27,
H, 6.20%.
4.2.10. Synthesis of [(g2-Me3SiC„CSiMe3)-
4.2.8. Synthesis of {[Ti](l-r,p-C„CSiMe3)2}-
CuO2CCH@CHFc (9b)
(CuO2CFc)2]2 (11)
[(g2-Me3SiC„CSiMe3)CuBr]2 (10) (280 mg, 0.446 mmol)
was dissolved in 70 mL of tetrahydrofuran and afterward
this solution was cooled to 0 ꢀC. [FcCO2Ag] (2a)
(300.0 mg, 0.892 mmol) was added in a single portion.
The reaction mixture was stirred for 3 h at 0 ꢀC and was
then filtered through a pad of Celite. The filtrate was evap-
orated to dryness in oil-pump vacuum and the remaining
solid was washed three times with 5 mL portions of n-hex-
ane and dried in oil-pump vacuum. Complex 11 was
obtained as an orange solid. Yield: 517 mg (0.342 mmol;
76.7% based on 2a).
FcCH@CHCO2H (1b) (52 mg, 0.20 mmol) dissolved in
20 mL of tetrahydrofuran was added dropwise to a stirred
solution of {[Ti](l-r,p-C„CSiMe3)2}CuMe (8) (120 mg,
0.20 mmol) in 20 mL of the same solvent at ꢀ30 ꢀC during
5 min. The reaction solution was stirred for 30 min at
ꢀ30 ꢀC and then 1 h at 25 ꢀC. Evaporation of the solvent
in oil-pump vacuum afforded 9b as a red solid. Yield:
167 mg (0.20 mmol, 100% based on 1b).
Mp. 108–110 ꢀC (dec.). IR (KBr, cmꢀ1): 2953 (m), 2896
(m), 1915 (w) m(C„C), 1637 (s) m(C@C), 1571 (w) mas(CO),
1463 (w), 1403 (s), 1374 (m), 1246 (s), 1176 (w), 1047 (w),
Mp. 128 ꢀC (dec.). IR (KBr, cmꢀ1): 2960 (w), 2899 (w),
1958 (w) m(C„C), 1586 (vs) mas(CO), 1481 (s), 1388 (s),
1361 (m), 1248 (m), 1194 (w), 1106 (m), 1074 (w), 1022
(m), 1001 (w), 847 (vs), 786 (m), 759 (m), 701 (w), 527
(w). 1H NMR (CDCl3): d 0.43 (s, 36H, CH3), 4.10 (s,
20H, C5H5), 4.19 (pt, JHH = 1.7 Hz, 8H, C5H4), 4.65 (pt,
JHH = 1.7 Hz, 8H, C5H4). 13C{1H} NMR: d 0.5 (CH3),
69.4 (C5H5), 70.0 (CH/C5H4), 70.6 (CH/C5H4). The signals
1
903 (w), 842 (vs), 757 (m), 679 (m), 496 (w). H NMR
(CDCl3): d 0.24 (s, 18H, CH3), 0.26 (s, 18H, CH3), 4.11 (s,
5H, C5H5), 4.28 (bs, 2H, C5H4), 4.46 (bs, 2H, C5H4), 5.98
(pt, JHH = 2.3 Hz, 4H, C5H4SiMe3), 6.11 (pt, JHH = 2.3 Hz,
3
4H, C5H4SiMe3), 6.24 (bd, JHH = 17 Hz, 1H, @CH), 7.31
(bd, 3J = 17 Hz, 1H, @CH). 13C{1H} NMR (CDCl3): d 0.4
(CH3), 0.5 (CH3), 68.4 (CH/C5H4), 69.7 (C5H5), 70.1 (CH/
C5H4), 113.5 (CH/C5H4SiMe3), 116.5 (CH/C5H4SiMe3),
121.8 (iC/C5H4SiMe3), 132.6 (TiC„CSiMe3), 171.3
i
for C/C5H4, „C, and HO2C could not be detected.
29Si{1H} NMR (CDCl3): d ꢀ5.6. ESI-MS [m/z (relative

J. Ku¨hnert et al. / Journal of Organometallic Chemistry 692 (2007) 4303–4314
4313
intensities)]: [M+ꢀMe3SiC„CSiMe3ꢀCu] 1277 (100).
Anal. Calc. for C60H72Cu4Fe4O8Si4 (1511.08): C, 47.69;
H, 4.80. Found: C, 47.78; H, 5.10%.
(br s, CH/C5H4), 81.9 (br s, iC/C5H4), 113.7 (CH/
C5H4SiMe3), 116.5 (CH/C5H4SiMe3), 121.9 (iC/
C5H4SiMe3), 127.2, 128.3, 128.7, 131.5 (Ph), 133.3
(TiC„CSiMe3), 133.5, 133.7, 134.7, 139.2 (Ph), 170.3
i
4.2.11. Synthesis of {[Ti](l-r,p-C„CSiMe3)2}-
CuO2CfcPPh2 (12)
(TiC„CSiMe3), 175.5 (COOH). The signal for the C/
C5H4 carbon atom could not be detected. 31P{1H} NMR
(CDCl3): d ꢀ17.9 (s). 29Si{1H} NMR (CDCl3): d ꢀ15.5
(Me3SiC„C), ꢀ6.0 (Me3SiC5H4). Anal. Calc. for
C49H62CuFeO3PSi4Ti (1009.56): C, 58.29; H, 6.19. Found:
C, 58.12; H, 6.69%.
Hdpf (75 mg, 0.18 mmol) dissolved in 15 mL of tetrahy-
drofuran was added dropwise to a stirred solution of
{[Ti](l-r,p-C„CSiMe3)2}CuMe (8) (107 mg, 0.18 mmol)
in 15 mL of the same solvent at ꢀ60 ꢀC. The reaction mix-
ture was stirred for 30 min at ꢀ60 ꢀC and then for 2 h at
25 ꢀC. Evaporation of all volatiles in oil-pump vacuum
afforded 12 as an orange solid. Yield: 179 mg (0.18 mmol,
100% based on Hdpf).
4.2.12. Synthesis of {[Ti](l-r,p-C„CSiMe3)2}-
CuO2CfcPPh2[Mo(CO)5] (15b)
The same procedure as for 12, (Hdpf)Mo(CO)5 (14b)
(40 mg, 0.06 mmol) in 15 mL of tetrahydrofuran is used
and reacted with {[Ti](l-r,p-C„CSiMe3)2}CuMe (8).
Compound 15b was obtained as a brown solid. Yield:
59 mg (96% based on 14b).
Mp. 89–91 ꢀC (dec.). IR (KBr, cmꢀ1): 3066 (w), 2952
(m), 2893 (m), 1915 (w) m(C„C), 1586 (m) mas(CO), 1463
(m), 1433 (w), 1388 (m), 1333 (m), 1245 (s), 1177 (w),
1094 (w), 1048 (m), 1023 (m), 903 (w), 839 (vs), 755 (m),
1
696 (m), 677 (m), 499 (w). H NMR (CDCl3): d 0.20 (s,
Mp. 123 ꢀC (dec.). IR (KBr, cmꢀ1): 2070 (s) m(CO), 1986
(s) m(CO), 1945 (vs), 1922 (sh) m(CO), 1604 (m), 1591 (m)
mas(CO), 1335 (m), 1246 (m), 1176 (w), 1163 (w), 1095
(w), 1049 (w), 1030 (w), 903 (w), 839 (composite s), 757
(w), 737 (w), 696 (w), 677 (w), 608 (w), 587 (m). 1H
NMR (CDCl3): d 0.18 (s, 18H, CH3), 0.24 (s, 18H, CH3),
4.00 (bs, 2H, C5H4), 4.30 (bs, 2H, C5H4), 4.44 (bs, 2H,
18H, CH3), 0.24 (s, 18H, CH3), 4.09 (bs, 2H, C5H4), 4.14
(bs, 2H, C5H4), 4.48 (bs, 2H, C5H4), 4.56 (bs, 2H, C5H4),
5.99 (pt, JHH = 2.3 Hz, 4H, C5H4SiMe3), 6.09 (pt,
JHH = 2.3 Hz, 4H, C5H4SiMe3), 7.20–7.40 (m, 10H, Ph).
13C{1H} NMR (CDCl3): d 0.3 (CH3), 0.4 (CH3), 70.9
(CH/C5H4), 71.1 (br s, CH/C5H4), 72.8 (CH/C5H4), 73.7
Table 3
Crystal and intensity collection data for compounds 5, 7, 9a, and 11
Compound
5
7
9a
11
Formula weight
Chemical formula
Crystal system
Space group
648.45
820.80
2128.44
C80H118Cl12Cu2Fe2O4Si8Ti2
Triclinic
755.55
C30H36Cu2Fe2O4Si2
Triclinic
C
24.5H21AgCl3FeO2P
C41H35AgClFeO2P2
Tetragonal
I41 (no. 80)
17.8803(4)
17.8803(4)
13.2474(7)
90
90
90
4235.3(3)
1.287
Tetragonal
P42/n (no. 86)
13.7539(4)
13.7539(4)
26.8981(17)
90
90
90
5088.3(4)
1.693
ꢀ
ꢀ
P1 ðno: 2Þ
P1 ðno: 2Þ
˚
a (A)
16.7085(6)
17.0597(8)
20.1037(9)
115.027(4)
95.616(4)
90.025(3)
5161.9(4)
1.369
11.346(3)
12.220(4)
13.539(3)
69.293(7)
80.638(10)
82.822(9)
1727.8(8)
1.452
˚
b (A)
˚
c (A)
a (ꢀ)
b (ꢀ)
c (ꢀ)
3
˚
V (A )
qcalc (g cmꢀ3
)
F(000)
2584
1168
2200
772
Crystal size dimensions (mm)
Z
0.4 · 0.3 · 0.3
8
0.672–1.000
1.738
0.3 · 0.2 · 0.2
4
0.844–1.000
0.973
0.4 · 0.2 · 0.2
2
–
1.271
100(2)
0.3 · 0.3 · 0.2
2
0.813–1.000
2.136
d
T-range transmission
l (mmꢀ1
T (K)
)
183(2)
183(2)
298(2)
h Range (ꢀ)
1.51–26.47
25680
5396
1.61–26.42
23236
4355
2.84–24.69
38059
17053
1.62–27.90
20194
8161
Total reflections
Unique reflections
Raint
5.84
2.00
4.35
2.19
Data/restraints/parameters
Sb
5257/34/322
1.071
4.49, 10.0
6.92, 11.3
0.744, ꢀ0.764
4347/1/265
1.044
1.91, 5.07
2.01, 5.13
0.209, ꢀ0.442
17053/0/981
0.883
6.08, 15.6
11.5, 16.9
1.204, ꢀ0.896
8161/0/368
1.013
2.58, 6.57
3.70, 7.04
0.475, ꢀ0.374
R, wR [I P 3r(I)]c
R, wR (ꢀal3l data)c
˚
Dq (e A
)
P
P
a
2
Rint
=
iFo j ꢀ jFo2(mean)i/ Fo2, where Fo2(mean) is the average intensity of symmetry-equivalent diffractions.
P
b
2
S = [ w(Fo ꢀ Fc2)2]/(n ꢀ p)1/2, where n = number of reflections, p = number of parameters.
P
P
P
P
c
2
R = [ (iFoj ꢀ jFci)/ jFoj]; wR = [ (w(Fo ꢀ Fc2)2)/ (wFo4)]1/2
.
d
Not corrected.

4314
J. Ku¨hnert et al. / Journal of Organometallic Chemistry 692 (2007) 4303–4314
[5] (a) For example: J. Haijun, C. Karine, J.A. Gladysz, J.-F. Halet, M.
Guillemot, L. Toupet, F. Paul, C. Lapinte, J. Am. Chem. Soc. 125
(2003) 9511;
C5H4), 4.61 (bs, 2H, C5H4), 6.00 (m, 4H, C5H4SiMe3), 6.10
(m, 4H, C5H4SiMe3), 7.35–7.55 (m, 10H, Ph). 13C{1H}
NMR (CDCl3):
d 0.3 (CH3), 0.4 (CH3), 71.0 (d,
(b) W. Skibar, H. Kopacka, K. Wurst, C. Salzmann, K.-H. Ongania,
F.F. de Biani, P. Zanello, B. Bildstein, Organometallics 23 (2004)
1024;
(c) C.L. Sterzot, J.K. Stille, Organometallics 9 (1990) 687;
(d) A. Mayboroda, P. Comba, H. Pritzkow, G. Rheinwald, H. Lang,
G. van Koten, Eur. J. Inorg. Chem. (2003) 1703.
JPC = 2 Hz, CH/C5H4), 71.3 (CH/C5H4), 74.0 (d,
JPC = 2 Hz, CH/C5H4), 74.2 (d, JPC = 8 Hz, CH/C5H4),
113.8 (CH/C5H4SiMe3), 116.6 (CH/C5H4SiMe3), 122.1
1
(iC/C5H4SiMe3), 128.2 (d, JPC = 9 Hz, CH/Ph), 129.8 (d,
JPC = 2 Hz, CH/Ph), 132.6 (d, JPC = 12 Hz, Ph), 133.5
ˇ
´
ˇ
´
´
[6] (a) J. Podlaha, P. Steˇpnicˇka, I. Cısarova, J. Ludvık, Organometallics
i
(TiC„CSiMe3), 138.4 (d, JPC = 38 Hz, C/PPh2), 170.1
15 (1996) 543;
2
ˇ
(TiC„CSiMe3), 206.0 (d, JPC = 9 Hz, CO). The signals
(b) P. Steˇpnicˇka, Eur. J. Inorg. Chem. (2005) 3787.
i
[7] N.G. Connelly, W.E. Geiger, Chem. Rev. 96 (1998) 877.
[8] (a) H. Lang, D.S.A. George, G. Rheinwald, Coord. Chem. Rev. 206–
207 (2000) 101;
(b) H. Lang, K. Ko¨hler, S. Blau, Coord. Chem. Rev. 143 (1995) 113.
[9] Z. Yuan, N.H. Dryden, J.J. Vittal, R.J. Puddephatt, Chem. Mater. 7
(1995) 1696.
for C/C5H4, HO2C and axial-CO could not be detected.
31P{1H} NMR (CDCl3): d 26.7 (s). 29Si{1H} NMR
(CDCl3): d ꢀ15.5 (Me3SiC„C), ꢀ6.0 (Me3SiC5H4). Due
to the high instability of this compound no satisfactory ele-
mental analysis could be obtained.
[10] W. Strohmeier, F.-J. Muller, Chem. Ber. 102 (1969) 3608.
¨
ˇ
´
´
´
ˇ
´
ˇ
ˇ
[11] L. Lukesˇova, J. Ludvık, I. Cısarova, P. Stepnicka, Collect. Czech.
4.3. Crystal structure determination
Chem. Commun. 65 (2000) 1897.
[12] J.E.D. Kirkham, T.D.L. Courtney, V. Lee, J.E. Baldwin, Tetrahe-
dron 61 (2005) 7219.
Crystal data for 5, 7, 9a, and 11 are presented in Table 3.
All data were collected on a Bruker Smart CCD 1k diffrac-
tometer at 298(2) K (11) or 183(2) K (5, 7) or on an Oxford
Gemini diffractometer at 100(2) K (9a) using oil-coated
shock-cooled crystals [26] using Mo Ka radiation
ˇ
ˇ
[13] P. Steˇpnicˇka, J. Demel, J. Cejka, J. Mol. Catal. A 224 (2004) 161.
[14] W. Frosch, S. Back, H. Muller, K. Ko¨hler, A. Driess, B. Schiemenz,
¨
G. Huttner, H. Lang, J. Organomet. Chem. 619 (2001) 99.
[15] W. Frosch, S. Back, G. Rheinwald, K. Ko¨hler, L. Zsolnai, G.
Huttner, H. Lang, Organometallics 19 (2000) 5769.
[16] G. Rabe, A.L. Rheingold, C.D. Incarvito, Z. Kristallogr. 215 (2000)
560.
[17] M. Bardet, M.F. Foray, S. Li, K. Lundquist, R. Stombert, J. Chem.
Crystallogr. 29 (1999) 1023.
[18] H. Lang, K. Ko¨hler, L. Zsolnai, Chem. Ber. 128 (1995) 519.
[19] (a) T.C.H. Lam, W.-L. Mak, W.-L. Wong, H.L. Kwong, H.H.Y.
Sung, S.M.F. Lo, I.D. Williams, W.-H. Leung, Organometallics 23
(6) (2004) 1247;
(b) C.W. Baxter, T.C. Higgs, A.C. Jones, S. Parsons, P.J. Bailey,
P.A. Tasker, J. Chem. Soc., Dalton Trans. (2002) 4395;
(c) P. Doppelt, T.H. Baum, J. Organomet. Chem. 517 (1996) 53.
[20] (a) A conversion of given electrode potentials to the standard normal
hydrogen electrode scale is possible H. Strehlow, W. Knoche, H.
Schneider, Ber. Bunsenges. Phys. Chem. 77 (1973) 760;
(b) G. Gritzner, J. Kuta, Pure Appl. Chem. 56 (1984) 461.
[21] T. Stein, H. Lang, R. Holze, J. Electroanal. Chem. 520 (2002) 163.
[22] G.D. Broadhead, J.M. Osgerby, P.L. Pauson, J. Chem. Soc. (1958)
650.
˚
(k = 0.71073 A). The structures were solved by direct meth-
ods using SHELXS-97 [27] and refined by full-matrix
least-square procedures on F2 using SHELXL-97 [28]. All
non-hydrogen atoms were refined anisotropically, and a
riding model was employed in the refinement of the hydro-
gen atom positions. In 5 a dichloromethane molecule is
disordered and has been refined to split occupancies of
0.54/0.46. In 11 the asymmetric unit contains a non-defin-
able solvent molecule. The electron density has been
deducted from the electron density map by the SQUEEZE
procedure implemented in PLATON-94 (vide supra) [29]. In 7
the asymmetric unit contains half of the molecule. The
second part is generated by the crystallographic C2-axis.
Acknowledgements
[23] K.L. Rinehart Jr., R.J. Curby Jr., P.E. Sokol, J. Am. Chem. Soc. 79
(1957) 3420.
[24] H. Lang, D. Seyferth, Z. Naturforsch. B 45 (1990) 212.
[25] W. Frosch, S. Back, H. Lang, J. Organomet. Chem. 621 (2001)
143.
We are grateful to the Deutsche Forschungsgemeins-
chaft and the Fonds der Chemischen Industrie for financial
support.
[26] (a) T. Kottke, D. Stalke, J. Appl. Crystallogr. 26 (1993) 615;
(b) T. Kottke, R.J. Lagow, D. Stalke, J. Appl. Crystallogr. 29 (1996)
465;
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