Heterobi- and -trinuclear complexes with an amino(ethynyl)carbene as bridging ligand

Article abstract of DOI:10.1002/zaac.200400162

The sequential reaction of the amino(trimethylsilyl)carbene complex [(CO)₅W=C(NH₂)C≡CSiMe₃] (1) with nBuLi and [I-Fe(CO)₂Cp] affords the C(carbene)-N bridged heterobinuclear complex [(CO)₅W=C{NHFe(CO)

Full text of DOI:10.1002/zaac.200400162

Heterobi- and -trinuclear Complexes with an Amino(ethynyl)carbene as Bridging
Ligand
Helmut Fischer*, Cornelia Hartbaum, Christiane Wespel, and Markus Dede
Konstanz, Fachbereich Chemie der Universität
Received May 13th, 2004.
Dedicated to Professor Michael Veith on the Occasion of his 60th Birthday
Abstract. The sequential reaction of the amino(trimethylsilyl)car-
bene complex [(CO)5WϭC(NH2)CϵCSiMe3] (1) with nBuLi and
[IϪFe(CO)2Cp] affords the C(carbene)-N bridged heterobinuclear
complex [(CO)5WϭC{NHFe(CO)2Cp}CϵCSiMe3] (2). Desilyl-
ation of 1 is achieved by treatment with KF in THF/MeOH. From
the reaction of the resulting complex [(CO)5WϭC(NH2)CϵCH] (3)
with nBuLi and [IϪFe(CO)2Cp] two binuclear WFe compounds
in a ratio of approximately 1:1 are obtained: the C(carbene)-CϵC
bridged complex 4 and the C(carbene)-N bridged complex 5. Rep-
etition of the deprotonation/metallation sequence yields the trinu-
clear WFe2 complex 6. One Fe(CO)2Cp fragment in 6 is bonded to
the amino group and the other one to the terminal carbon atom
of the ethynyl substituent. The analogous reaction of 3 with nBuLi
and [BrϪNi(PMe2Ph)2Mes] gives a ca. 1:1 mixture of two heterobi-
nuclear complexes (7 and 8). Complex 7 is bridged by the
C(carbene)ϪCϵC and complex 8 by the C(carbene)ϪN fragment.
Subsequent reaction of 7 with BuLi and [BrϪNi(PMe2Ph)2Mes]
finally affords the trinuclear WNi2 complex 9 related to 6. The
solid-state structure of 2 is established by an X-ray diffraction
analysis. The spectroscopic data of the bi- and trinuclear complexes
indicate electronic communication between the metal centers
through the bridging group.
Keywords: Carbene complexes; Alkynyl complexes; Tungsten;
Bridging ligands; N ligands; Iron; Nickel.
Heterobi- und -trinukleare Komplexe mit einem verbückenden Amino(ethinyl)carben-
Liganden
Inhaltsübersicht. Bei der Reaktion des Amino(trimethylsilyl)carben-
Komplexes [(CO)5WϭC(NH2)CϵCSiMe3] (1) mit nBuLi und
nachfolgend mit [IϪFe(CO)2Cp] entsteht der C(Carben)-N-
Fragment in 6 ist an die Aminogruppe und das andere an das ter-
minale Kohlenstoffatom des Ethinylsubstituenten gebunden. Die
analoge Reaktion von 3 mit nBuLi und [BrϪNi(PMe2Ph)2Mes] er-
gibt ein ca. 1:1-Gemisch zweier heterobinuklearer WNi-Komplexe
(7 und 8). Der Komplex 7 ist C(Carben)ϪCϵC- und der Komplex
8 C(Carben)-N-verbrückt. Durch nachfolgende Reaktion von 7 mit
nBuLi und [BrϪNi(PMe2Ph)2Mes] erhält man schließlich den mit 6
verwandten dreikernigen WNi2-Komplex 9. Die Festkörperstruktur
von 2 wurde mithilfe einer Einkristallstrukturanalyse bestimmt.
Die spektroskopischen Daten der di- und trinuklearen Komplexe
sprechen für eine elektronische Wechselwirkung der Metallatome
durch den verbrückenden Liganden.
verbrückte
heterodinukleare
Komplex
[(CO)5Wϭ
C{NHFe(CO)2Cp}CϵCSiMe3] (2). Die Desilylierung von 1 lässt
sich durch Behandlung mit KF in THF/MeOH erreichen. Die Re-
aktion des resultierenden Komplexes [(CO)5WϭC(NH2)CϵCH]
(3) mit nBuLi und [IϪFe(CO)2Cp] liefert zwei dinukleare WFe Ver-
bindungen im Verhältnis von ungefähr 1:1: den C(Carben)ϪCϵC-
verbrückten Komplex 4 und den C(Carben)-N-verbrückten Kom-
plex 5. Die Wiederholung der Deprotonierungs-/Metallierungsse-
quenz führt zum trinuklearen WFe2-Komplex 6. Ein Fe(CO)2Cp-
Introduction
* Prof. Dr. H. Fischer
Fachbereich Chemie
Universität Konstanz
Fach M727
D-78457 Konstanz
Fax: (49) 7531 883136
e-mail: helmut.fischer@uni-konstanz.de
Bi- and polynuclear transition-metal complexes containing
unsaturated conjugated carbon bridges are expected to ex-
hibit potentially useful physical and chemical properties
such as liquid crystalline properties [1] and second-order or
third-order nonlinear optical properties [2]. The electronic
communication between metal centers in such complexes
can be mediated in different ways [3]. Various types of
bridging ligands have been proposed and studied in detail.
Supporting information for this article is available on the
WWW under http://www.wiley-vch.de/home/zaac or from the
author
Z. Anorg. Allg. Chem. 2004, 630, 1863Ϫ1868
DOI: 10.1002/zaac.200400162
 2004 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
1863

H. Fischer, C. Hartbaum, C. Wespel, M. Dede
Scheme 1
In previous years attention has focused on carbon-rich
bridges [4].
We recently described a series of heterobinuclear alkynyl-
(dimethylamino)carbene complexes in which a (CO)5M
(M ϭ Cr, W) and a MЈLn fragment are linked by a
“C(NMe2)Ϫ(CϵC)n” bridging ligand. In these complexes
the (CO)5M fragment (M ϭ Cr, W) is bonded to the bridge
via a MϭC(carbene) and the MЈLn fragment via a
MЈϪ(CϵC)n bond (n ϭ 1 Ϫ 3 [5, 6]). Tri-, tetra-, and
pentanuclear complexes were prepared as well [6, 7]. We
now report on the synthesis of (a) isomeric binuclear ami-
no(ethynyl)carbene pentacarbonyl complexes differing in
the position of the MЈLn fragment (ϵC- or N-bound) and
(b) of trinuclear complexes with ϵC- and N-bound MЈLn
fragments.
Fig. 1 Structure of complex 2 in the crystal (ellipsoids drawn at
50 % level, hydrogen atoms omitted for clarity). Important distan-
˚
ces/A and angles/° are:
W(1)-C(8) 2.275(9), C(8)-N(1) 1.309(11), C(8)-C(9) 1.451(12), C(9)-C(10)
1.220(13), C(10)-Si(1) 1.858(11), N(1)-Fe(1) 1.986(7); W(1)-C(8)-C(9)
116.2(6), C(8)-C(9)-C(10) 173.7(10), W(1)-C(8)-N(1) 126.0(6), C(8)-N(1)-
Fe(1) 131.4(6); C(4)-W(1)-C(8)-N(1) 68.6(8), W(1)-C(8)-N(1)-Fe(1) 176.2(4),
C(8)-N(1)-Fe(1)-C(6) -56.7(9), C(8)-N(1)-Fe(1)-C(7) -149.1(9).
Results and Discussion
Deprotonation of the amino(trimethylsilylethynyl)carbene
complex 1 at Ϫ80 °C and subsequent reaction of the re-
sulting metallate at room temperature with [IϪFe(CO)2Cp]
(Cp ϭ η5-C5H5) affords, after chromatography, the N-met-
allated carbene complex 2 in 81 % yield (Scheme 1). The
starting complex 1 is obtained by sequential reaction of
[W(CO)6] with trimethylsilylethynyl lithium and methyl
triflate followed by aminolysis with NH3.
density at the pentacarbonyltungsten moiety. With respect
to the partial C(carbene)ϪN double bond the formation of
only one isomer can be detected. Steric considerations sug-
gest that the E-isomer is formed as shown in Scheme 1. The
observation of only three CO resonances in the 13C NMR
spectra (two signals for the W(CO)5 and one peak for the
Fe(CO)2 moiety) indicates that either (a) there is rapid ro-
tation around the NϪFe bond or (b) the mirror plane of
the Fe(CO)2Cp fragment coincides (or nearly coincides)
with the carbene plane formed by W, C(carbene), N, and
CϵC. The solid-state structure of 2 (Figure 1) renders op-
tion (a) in solution more likely: the mirror plane of the
Fe(CO)2Cp fragment is strongly tilted against the carbene
plane (torsion angle C(8)ϪN(1)ϪFeϪC(6) Ϫ56.7(9)° and
(C(8)ϪN(1)ϪFeϪC(7) Ϫ149.1(9)°). As is often observed
with pentacarbonyl carbene complexes the carbene plane
1
From the H and 13C NMR spectra of 2 it follows that
an N-bound hydrogen atom has been replaced by the
Fe(CO)2Cp fragment. Peaks due to the trimethylsilyl group
are still present in the spectra. The related C-metallated
C(NMe2)ϪCϵC bridged complex has previously been pre-
pared [5a].
The mononuclear complex 1 exhibits five partially over-
lapping ν(CO) absorptions indicating that the local C4v
symmetry of the W(CO)5 fragment has been reduced to
either Cs or even C1. Therefore, for the binuclear complex
2 seven absorptions are to be expected, five for the W(CO)5
and two for the Fe(CO)2 part of the molecule. However,
only six are observed. Obviously, two of the ν(CO) absorp-
tions of the W(CO)5 fragment that in 1 already strongly
overlap are in 2 even more similar in energy and are not
resolved any more. A similar situation applies to the other
binuclear complexes described below.
adopts
a
staggered conformation (torsion angle
C(4)ϪW(1)ϪC(8)ϪN(1) 68.6(8)°). The C(8)ϪN(1) distance
˚
(1.309(11) A) is slightly shorter than that expected for a
2
2
˚
C(sp )ϪN(sp ) single bond (1.339 A [8]) and compares well
with that observed for other alkynyl(amino)carbene com-
plexes indicating considerable double bond character. The
W(1)ϪC(8) distance is at the long end of the range usually
determined for tungsten(0)-carbene complexes.
When treated with potassium fluoride in THF/methanol,
the amino(trimethylsilylethynyl)carbene complex 1 is trans-
formed into the amino(ethynyl)carbene complex 3. Com-
pound 3 is isolable and stable at room temperature. In con-
trast, the related alkoxy(ethynyl)carbene complexes are
The reaction can readily be followed by IR spectroscopy.
The ν(CO) vibrations shift towards smaller wave numbers
indicating that the replacement of an N-bound hydrogen
atom by the Fe(CO)2Cp fragment increases the electron
1864
 2004 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
zaac.wiley-vch.de
Z. Anorg. Allg. Chem. 2004, 630, 1863Ϫ1868

Heterobi- and -trinuclear Complexes with an Amino(ethynyl)carbene as Bridging Ligand
Scheme 3
observation that replacement of the C-bound hydrogen
atom in 3 by Fe(CO)2Cp gives rise to a high-field shift of
the carbene resonance in the 13C NMR spectrum. In
contrast, the carbene resonance in 5 is observed at lower
field when compared to the unsubstituted complex 3.
Repetition of the sequence deprotonation/metallation
with [IϪFe(CO)2Cp] (Scheme 2) affords after chromatogra-
phy the trinuclear complex 6 in 52 % overall yield. The ef-
fects of replacing two hydrogen atoms by two organometal-
lic donor groups are essentially additive. The ν(CO) absorp-
tions of the (CO)5W fragment are at even lower energy than
those of 4 and 5 and the low-field shift of the resonances
of the cis and trans W-bound CO groups caused by the
transformation of 3 into 6 is approximately that of 3 into 4
and 3 into 5 combined. Consequently the high-field (3 Ǟ
4) resp. low-field shifts (3 Ǟ 5) of the carbene resonance
cancel each other and the peak of the carbene carbon atom
in 6 is found at the same position as that of the unsubsti-
tuted complex 3. Despite the presence of two bulky
Fe(CO)2Cp substituents only two FeϪCO and Cp reson-
ances or observed in the 13C NMR spectrum. This indicates
that the two Fe(CO)2Cp groups are not interlocked but ro-
tate freely.
Scheme 2
highly reactive and quickly decomposes in solution even at
Ϫ78 °C. Contrary to the reaction of 1 with nBuLi and
[IϪFe(CO)2Cp] that of 3 affords two isomeric substitution
products (Scheme 2).
Column chromatographic separation yields the two iso-
mers 4 and 5 in pure form that differ in the position of the
Fe(CO)2Cp fragment. The complexes are obtained in a ratio
of nearly 1:1 indicating that NϪH and ϵCϪH depro-
tonation are almost equally likely. Complex 4 corresponds
to the C(NMe2)ϪCϵC bridged binuclear complexes re-
ported earlier, 5 is the ethynyl analogue to the trimethylsily-
lethynyl-substituted complex 2.
From the ν(CO) absorptions (E- and A1(trans)) of the
W(CO)5 fragment it follows that the overall σ-donor/π-ac-
ceptor ratio of the carbene ligand in 4 and 5 is only mar-
ginally influenced by the position of the Fe(CO)2Cp frag-
ment (N- or C-bound). In turn, the ν(CO) absorptions of
the Fe(CO)2Cp moiety depend on the coordination site. The
absorptions of the C-bound fragment are observed at signif-
icantly smaller wave numbers than those of the N-bound
one. In contrast to 1, 2, 3, and 5 the ν(CϵC) of 4 can be
identified. The vibration is observed at 2074 cmϪ1 and is at
lower energy than in [Cp(CO)2FeϪCϵCR] complexes
[ν(CϵC) ϭ 2115 cmϪ1 (R ϭ Ph); 2110 cmϪ1 (R ϭ CO-
OMe)] [9] indicating considerable interaction of the
Fe(CO)2Cp fragment with the carbene(pentacarbonyl)-
tungsten moiety. In agreement with this conclusion is the
From the reactions of
3
with nBuLi and
[BrϪNi(PMe2Ph)2Mes] the binuclear complexes 7 and 8 are
obtained, again in a ratio of approximately 1:1. Subsequent
treatment of 7 with BuLi and [BrϪNi(PMe2Ph)2Mes] yields
the trinuclear complex 9 (Scheme 3).
In general, the spectroscopic consequences of the substi-
tution of [BrϪNi(PMe2Ph)2Mes] for hydrogen are similar to
those described above although the effects are more pro-
nounced. The ν(CO) absorptions of the (CO)5W fragment
are at lower energy than those of 4 Ϫ 6 indicating enhanced
interaction of Ni(PMe2Ph)2Mes with (CO)5W when com-
Z. Anorg. Allg. Chem. 2004, 630, 1863Ϫ1868
zaac.wiley-vch.de
 2004 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
1865

H. Fischer, C. Hartbaum, C. Wespel, M. Dede
pared to Fe(CO)2Cp. In accord with the conclusion the
ν(CϵC) absorption in 7 and 9 is found at smaller wave num-
ber than in 4 and 6. As with 4 Ϫ 6, the 13C NMR resonance
of the trans carbonyl carbon atom is at lower field than that
of 3 and the low-field shift caused by replacing two H atoms
by the organometallic fragment is roughly twice that of a
single substitution. Unlike 4 Ϫ 6, all complexes 7 Ϫ 9 exhibit
the carbene resonance at higher field than 3.
nyl hydrogen and it is also more pronounced than that of a
Fe(CO)2Cp fragment.
Experimental
All operations were performed under argon by using standard
Schlenk techniques. Solvents were dried by refluxing over CaH2
(CH2Cl2) and sodium/benzophenone ketyl (pentane, Et2O, THF)
and were freshly distilled prior to use. The yields refer to analyti-
cally pure compounds and were not optimized. Silica gel used for
column chromatography (Fa. J. T. Baker, silica gel for flash chroma-
tography) was argon-saturated. The complexes [BrNi(P-
Me2Ph)2(Mes)] [11] and [IFe(CO)2Cp] [12] were prepared according
to literature procedures. HCϵCSiMe3 was a gift from Wacker
Chemie GmbH. NMR spectra were determined on Bruker AC 250,
Bruker WM 250, and Jeol JNX 400 instruments; chemical shifts
are reported relative to internal TMS (1H and 13C) or external
H3PO4 (31P). IR spectra were measured on a Biorad FTS 60 spec-
trometer. MS determinations were carried out on a Finnigan MAT
312 instrument and elemental analyses on a Heraeus CHN-O-RA-
PID.
Complex 7 shows only one 31P NMR resonance. Like-
wise, only one set of signals for the two PMe2Ph ligands
and one resonance for the two o-methyl groups of the mes-
1
ityl ligand are observed in the H and the 13C NMR spec-
tra. These signals do not broaden on cooling solutions
down to Ϫ50 °C. These observations agree with a rapid
rotation of the Ni(PMe2Ph)2Mes fragment around the
ϵC-Ni bond.
In contrast, the N-bound Ni(PMe2Ph)2Mes fragment in
8 exhibits two PMe2, o-Me, and m-CH resonances each in
1
the H and the 13C NMR spectra. However, there is only
one signal in the 31P NMR spectrum. Several
[XϪNi(PR3)2(Aryl)] complexes have been characterized by
X-ray structural analyses [10]. In all of them the nickel atom
is square-planar coordinated and the plane of the aromatic
ligand is oriented perpendicular to the molecular plane. An
analogous arrangement can be assumed for 8. The NMR
spectroscopic data are best explained by assuming that (a)
the carbene plane (formed by the atoms W, C(carbene), N,
and CϵC) and the aromatic plane coincide, (b) the
PϪNiϪP axis is perpendicular to these planes, and (c) free
rotation of the PMe2Ph ligands around the PϪNi axis is re-
stricted.
1-Amino-3-trimethylsilylpropynylidene(pentacarbonyl)tungsten (1):
At Ϫ80 °C, 28.3 mmol of nBuLi (17.7 ml of a 1.6 M solution in
hexane) are added to
a solution of 28.3 mmol (2.78 g) of
HCϵCSiMe3 in 160 ml of Et2O. The solution is stirred for 30 min
at 0 °C. 28.3 mmol (9.96 g) of [W(CO)6] in 10 ml of THF are added
and the resulting suspension is stirred for 1 h at room temp. The
color gradually changes from slight yellow to dark orange. At 0 °C
42.5 mmol (6.97 g) of F3CSO3Me are added. Within 15 min at 0 °C
the solution turns brown. The solution is cooled to Ϫ100 °C and
56.6 mmol of NH3 (4.24 ml of a 25 % solution in water) is added.
Subsequently the yellow solution is extracted three times with
200 ml of a saturated aqueous NaHCO3 solution. The organic
phase is dried with Na2SO4 and the solvent is removed in vacuo.
The yellow-brown residue is dissolved in 100 ml of pentane/CH2Cl2
(9:1) and chromatographed at Ϫ40 °C. First with pentane/CH2Cl2
(5:1) yellow bands are eluted. The first one contains [W(CO)6] and
the second broad one the product. Removal of the solvent in vacuo
affords a yellow solid.
As expected on the basis of the NMR data of 7 and 8,
1
the H NMR spectrum of complex 9 at room temperature
shows three PMe2 and three o-CH3 resonances (intensity
ratio 2:1:1 each). On cooling solutions of 9, the PMe2 and
o-CH3 peaks assigned to the C-bound Ni(PMe2Ph)2Mes
fragment broaden and finally split into two signals indicat-
ing restricted rotation around the C-Ni bond at low tem-
perature. From the coalescence temperature the barrier to
rotation can be estimated to be ∆G϶ ϭ 48 3 kJ/mol. The
signal at δ ϭ 15.17 in the 13C NMR spectrum assigned to
the C-bound Ni-PMe2 groups likewise broadens on cooling.
The 31P NMR spectrum, however, shows at room tempera-
ture only one signal for each of the two Ni(PMe2Ph)2Mes
substituents.
These observations confirm the conclusions that can be
drawn from the spectra of 7 and 8. The barrier to rotation
around the NϪNi bond is significantly higher than to ro-
tation around the ϵCϪNi bond very likely due to interac-
tion of the nickel with the lone pair at nitrogen. Replacing
an amino hydrogen atom by the bulky Ni(PMe2Ph)2Mes
group increases the barrier to rotation around the ϵCϪNi
bond presumably for steric reasons.
Yield 10.8 g [85 % relative to W(CO)6]. M.p. 58 °C.
Elemental analysis (for C11H11NO5SiW [449.2]) found (calc.) [%]:
C 29.44 (29.42); H 2.55 (2.47); N 3.10 (3.12).
IR (pentane): ν(CO) 2067 w, 1981 w, 1951 vs, 1943 sh, 1926 sh cmϪ1
.
1H NMR (CDCl3): δ ϭ 0.27 (s, 9 H, CH3), 8.48 (br. s, 1 H, NH), 8.61 (br. s,
1 H, NH).
13C NMR (CDCl3): δ ϭ Ϫ0.79 (CH3), 108.62 (Cβ), 128.53 (Cα), 197.81
[J(WC) ϭ 127.0 Hz, cis-CO], 204.00 [J(WC) ϭ 126.9 Hz, trans-CO], 244.14
[J(WC) ϭ 86.6 Hz, WϭC].
MS (70 eV): m/z ϭ 449 (38) (Mϩ, 38 %), 393, 365, 337, 309 (MϩϪn CO, n ϭ
2 Ϫ 5; 62, 60, 71, and 100 %), 292 (MϩϪ3 COϪSiMe3, 28 %), 264 (MϩϪ4
COϪSiMe3, 27 %).
Pentacarbonyl{N-dicarbonyl(η5-cyclopentadienyl)ferrio]amino-3-tri-
methylsilylpropynylidene}-tungsten (2): At Ϫ80 °C 2.00 mmol
(0.90 g) of 1 in 13 ml of Et2O are deprotonated with 2.00 mmol of
nBuLi (1.25 ml of a 1.6 M solution in hexane). After 30 min at
Ϫ80 °C 2.00 mmol (0.64 g) of [(η5-C5H5)(CO)2FeI] in 7.5 ml of
THF are added. The solution is stirred for 30 min at room temp.
The solvent is removed in vacuo. The residue is dissolved in 10 ml
of CH2Cl2 and chromatographed at Ϫ40 °C. With pentane/CH2Cl2
(7:3) an orange band is eluted. Removal of the solvent and recrys-
tallization from 25 ml of CH2Cl2/pentane (2:3) gives brown crystals.
In summary, the interaction of the (CO)5WϭC(carbene)
unit with Ni(PMe2Ph)2Mes is more pronounced when this
substituent replaces an amino hydrogen instead of the ethy-
1866
 2004 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
zaac.wiley-vch.de
Z. Anorg. Allg. Chem. 2004, 630, 1863Ϫ1868

Heterobi- and -trinuclear Complexes with an Amino(ethynyl)carbene as Bridging Ligand
13C NMR (CDCl3): δ ϭ 86.12 (C5H5), 91.74 (Cβ), 106.83 (Cα), 199.97
Yield 1.01 g (81 % relative to 1). Dec. at 112 °C.
Elemental analysis (for C18H15FeNO7SiW (625.10) found (calc.)
[%]: C 34.57 (34.59); H 2.44 (2.42); N 1.95 (2.24).
[J(WC) ϭ 127.3 Hz, cis-WCO], 204.56 (trans-WCO), 210.84 (FeCO), 249.52
(WϭC).
MS (70 eV): m/z ϭ 553 (Mϩ, 40 %), 525, 497, 469, 441, 413, 385, 357 (MϩϪn
CO, n ϭ 1 Ϫ 7; 4, 17, 22, 23, 28, 39, and 66 %), 121 (Fe[C5H5]ϩ, 82 %), 56
(Feϩ, 100 %).
IR (CH2Cl2): ν(CO) 2060 w, 2047 m, 2005 w, 1969 vw, 1920 vs, 1892 sh cmϪ1
.
1H NMR (CDCl3): δ ϭ 0.28 (s, 9 H, SiCH3), 5.07 (s, 5 H, C5H5), 7.40 (br. s,
1 H, NH).
13C NMR (CDCl3): δ ϭ Ϫ0.52 (SiCH3), 86.06 (C5H5), 112.36 (Cβ), 126.55
(Cα), 200.15 [J(WC) ϭ 128.0 Hz, cis-WCO], 204.80 (trans-WCO), 210.92
(FeCO), 249.12 (WϭC).
1-N-dicarbonyl(η5-cyclopentadienyl)ferrio]amino-3-dicarbonyl(η5-
cyclopenta-dienyl)ferrio]propynylidene(pentacarbonyl)tungsten (6): A
solution containing 4 and 5 (obtained by deprotonation of
4.00 mmol (1.51 g) of 3 and subsequent reaction with 4.00 mmol
(1.27 g) of [IFe(CO)2Cp]) is cooled to Ϫ80 °C. 4.00 mmol of nBuLi
in hexane are added. The resulting dark solution is stirred for
30 min at Ϫ80 °C and 4.00 mmol (1.27 g) of [IFe(CO)2Cp] in 15 ml
THF are added. The solution is stirred for 30 min at room temp.
The solvent is removed in vacuo. The residue is dissolved in 10 ml
of CH2Cl2 and chromatographed at Ϫ40 °C. With pentane/CH2Cl2
(7:3) a brown band is eluted. Removal of the solvent and recystal-
lization from 25 ml of pentane/CH2Cl2 (6:5) gives 6 as orange
needles.
MS (70 eV): m/z ϭ 625 (Mϩ, 19 %), 597, 569, 541, 513, 485, 457, 429
(MϩϪCO, n ϭ 1 Ϫ 7; 6, 24, 36, 29, 34, 100, and 78 %), 121 (Fe[C5H5]ϩ,
45 %).
1-Aminopropynylidene(pentacarbonyl)tungsten (3): First, 3.44 mmol
(0.20 g) of KF and then 200 ml of CH2Cl2 are added to a solution
of 15.00 mmol (6.74 g) of 1 in 80 ml of THF/MeOH (1:1). The
resulting yellow solution is three times extracted with 150 ml of a
saturated aqueous solution of NaHCO3 each. The organic phase is
dried with Na2SO4. The solvent is removed in vacuo. The residue
is dissolved in 60 ml of pentane and chromatographed at Ϫ40 °C.
With pentane/CH2Cl2 (4:1) a yellow band is eluted. Removal of the
solvent affords 3 as a yellow powder.
Yield 1.51 g (52 % relative to 3). Dec. at 125 °C.
Elemental analysis (for C22H10Fe2NO9W [728.87]) found (calc.)
[%]: C 36.35 (36.30); H 1.75 (1.38); N 1.65 (1.92).
Yield 3.73 g (66 % relative to 3). Dec. at 81 °C.
Elemental analysis (for C8H3NO5W [377.0]) found (calc.) [%]: C
25.27 (25.49); H 0.90 (0.80); N 3.86 (3.72).
IR (CH2Cl2): ν(CO) 2057 w, 2043 m, 2036 sh, 1996 m, 1956 vw, 1910 vs,
1882 sh; ν(CϵC) 2075 vw cmϪ1
.
1H NMR (CDCl3): δ ϭ 5.01 (s, 5 H, C5H5), 5.11 (s, 5 H, C5H5), 8.74 (br. s,
1 H, NH).
IR (pentane): ν(CO) 2070 w, 1985 w, 1955 vs, 1944 sh, 1932 sh cmϪ1
1H NMR (CDCl3): δ ϭ 5.28 (s, 1 H, CϵCH), 8.72 (br. s, 2 H, NH).
.
13C NMR (CDCl3): δ ϭ 85.63 (C5H5), 85.69 (C5H5), 85.75 (C5H5), 85.87
(C5H5), 85.93 (C5H5), 86.01 (C5H5), 134.06 (Cβ), 137.29 (Cα), 201.38 (cis-
WCO), 205.66 (trans-WCO), 212.01 (FeCO), 212.09 (FeCO), 244.84 (WϭC).
MS (70 eV): m/z ϭ 729 (Mϩ, 2 %), 701, 673, 645, 617, 589 (MϩϪn CO,
n ϭ 1-5; 3, 1, 3, 4, and 3 %), 468 (MϩϪ7 COϪCp, 26 %), 412 (34) (MϩϪ7
COϪCpϪFe, 34 %), 121 (Fe[C5H5]ϩ, 100 %), 56 (Feϩ, 90 %).
13C NMR (CDCl3): δ ϭ 88.49 (Cβ), 105.91 (Cα), 197.51 [J(WC) ϭ 128.1 Hz,
cis-CO], 203.72 [J(WC) ϭ 125.9 Hz, trans-CO], 244.54 [J(WC) ϭ 88.2 Hz,
WϭC].
MS (70 eV): m/z ϭ 377 (Mϩ, 41 %), 321, 293, 265, 237 (MϩϪn CO, n ϭ 2
Ϫ 5; 38, 63, 100, and 81 %).
1-Amino-3-dicarbonyl(η5-cyclopentadienyl)ferrio]propynylidene-
(pentacarbonyl)-tungsten (4) and Pentacarbonyl{1-dicarbonyl(η5-
1-Amino-3-[trans-bis(dimethylphenylphosphane)mesitylnickelio]-
propynylidene-(pentacarbonyl)tungsten (7) and 1-N-[trans-bis(dimeth-
ylphenylphosphane)mesityl-nickelio]aminopropynylidene(penta-
carbonyl)tungsten (8): The complexes 7 and 8 are prepared and
cyclopentadienyl)ferrio]amino-propynylidene}tungsten
(5):
At
Ϫ80 °C 4.00 mmol (1.51 g) of 3 in 25 ml of Et2O are deprotonated
with 4.00 mmol of nBuLi (2.5 ml of a 1.6 M solution in hexane).
When the yellow solution is stirred for 30 min at Ϫ80 °C, a white
precipitate forms. 4.00 mmol (1.27 g) of [IFe(CO)2Cp] in 15 ml of
THF are added. The solution is allowed to warm to room temp.
and is stirred for 30 min. The solvent is removed in vacuo, the resi-
due is dissolved in 8 ml of CH2Cl2 and chromatographed at
Ϫ40 °C. With pentane/CH2Cl2 (3:1) a yellow band containing 4
and with pentane/CH2Cl2 (2:1) a second yellow band containing 5
is eluted. Removal of the solvent affords 4 and 5 as beige solids.
4: Yield 0.22 g (10 % relative to 3). Dec. at 113 °C.
purified analogously to
4 and 5. Instead of [Fe(CO)2Cp],
4.00 mmol (2.14 g) of [BrNi(PMe2Ph)2Mes] in 15 ml of THF is
used in the reaction with deprotonated 3. Compounds 7 and 8 are
yellow solids.
7: Yield 0.76 g (23 % relative to 3). Dec. at 110 °C.
Elemental analysis (for C33H35NNiO5P2W [830.1]) found (calc.)
[%]: C 47.64 (47.75); H 4.34 (4.25); N 1.83 (1.69).
IR (THF): ν(CO) 2058 w, 1963 w, 1920 vs, 1898 m; ν(CϵC) ϭ 2020 w cmϪ1
.
1H NMR (CDCl3, Ϫ50 °C): δ ϭ 1.20 (s, 12 H, PCH3), 2.19 (s, 3 H, p-CH3),
2.22 (s, 6 H, o-CH3), 6.55 (s, 2 H, m-H of Mes), 7.14 (br. s, 1 H, NH), 7.46
(mc, 6 H, C6H5), 7.60 (mc, 4 H, C6H5), 8.38 (br. s, 1 H, NH).
13C NMR (CDCl3, Ϫ40 °C): δ ϭ 14.16 [J(PC) ϭ 16.1 Hz, PCH3], 20.69 (p-
CH3), 25.18 (o-CH3), 125.98, 128.16 [J(PC) ϭ 3.8 Hz], 129.51, 130.76
[J(PC) ϭ 4.8 Hz], 131.82 (o-, m-, p-C of C6H5, m-, p-C of Mes, Cb), 135.58
[J(PC) ϭ 20.9 Hz, ipso-C of C6H5], 141.76 [J(PC) ϭ 3.0 Hz, o-C of Mes],
155.14 [J(PC) ϭ 30.4 Hz, ipso-C of Mes], 180.02 [J(PC) ϭ 30.2 Hz, Ca],
198.84 [J(WC) ϭ 127.3 Hz, cis-CO], 204.46 (trans-CO), 231.58 [J(WC) ϭ
83.5 Hz, WϭC].
Elemental analysis (for C15H7FeNO7W [552.9] found (calc.) [%]: C
32.75 (32.58); H 1.37 (1.28); N 2.45 (2.53).
IR (Et2O): ν(CO) 2060 w, 2035 m, 2001 m, 1961 w, 1923 vs, 1908 sh; ν(CϵC)
2074 w cmϪ1
.
1H NMR (CDCl3): δ ϭ 5.12 (s, 5 H, C5H5), 7.83 (br. s, 1 H, NH), 8.24 (br.
s, 1 H, NH).
13C NMR (CDCl3): δ ϭ 85.80 (C5H5), 130.25 (Cβ), 151.52 (Cα), 199.20
[J(WC) ϭ 126.9 Hz, cis-WCO], 204.53 (trans-WCO), 210.72 (FeCO), 239.62
(WϭC).
31P-NMR (CDCl3): δ ϭ 1.02.
MS (FAB, NBOH): m/z ϭ 829 (Mϩ, 5 %), 773, 745, 717, 689 (MϩϪn CO,
n ϭ 2 Ϫ 5; 6, 5, 12, and 7 %).
MS (70 eV): m/z ϭ 553 (Mϩ, 5 %), 525, 497, 469, 441, 413, 385, 357 (MϩϪn
CO, n ϭ 1 Ϫ 7; 1, 1, 5, 4, 8, 18, and 17 %), 121 (Fe[C5H5]ϩ, 100 %), 56
(Feϩ, 100 %).
8: Yield 0.63 g (19 % relative to 3). Dec. at 84 °C.
Elemental analysis (for C33H35NNiO5P2W [830.1]) found (calc.)
[%]: C 47.72 (47.75); H 4.30 (4.25); N 1.83 (1.80).
5: Yield 0.18 g (8 % relative to 3). Dec. at 97 °C.
Elemental analysis (for C15H7FeNO7W [552.9]) found (calc.) [%]:
C 32.47 (32.58); H 1.32 (1.28); N 2.65 (2.53).
IR (THF): ν(CO) 2054 w, 1961 w, 1915 vs, 1894 m cmϪ1
.
1H NMR (CDCl3, Ϫ40 °C): δ ϭ 1.01 [J(PH) ϭ 3.5 Hz, 6 H, PCH3], 1.50
[J(PH) ϭ 3.1 Hz, 6 H, PCH3), 2.20, 2.28, 2.49 (3 ϫ s, 3 ϫ 3 H, p-CH3 and
o-CH3), 4.80 (s, 1 H, CϵCH), 6.46 (s, 1 H, m-H of Mes), 6.48 (s, 1 H, m-H
of Mes), 7.16Ϫ7.22 (m, 4 H, C6H5), 7.35Ϫ7.47 (m, 6 H, C6H5), 8.38 (br. s,
1 H, NH).
IR (Et2O): ν(CO) 2061 w, 2047 m, 2007 m, 1967 w, 1925 vs, 1905 m cmϪ1
.
1H NMR (CDCl3): δ ϭ 5.12 (s, 5 H, C5H5), 5.43 (s, 1 H, CϵCH), 7.62 (br.
s, 1 H, NH).
Z. Anorg. Allg. Chem. 2004, 630, 1863Ϫ1868
zaac.wiley-vch.de
 2004 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
1867

H. Fischer, C. Hartbaum, C. Wespel, M. Dede
13C NMR (CDCl3, Ϫ40 °C): δ ϭ 12.03 [J(PC) ϭ 16.1 Hz, PCH3], 12.77
[J(PC) ϭ 13.3 Hz, PCH3], 20.56, 24.45, 25.33 (p-CH3, o-CH3), 92.57, 95.93
(Cα, Cβ), 126.17, 129.30 (m-C of Mes, p-C of C6H5), 128.33 [J(PC) ϭ
3.8 Hz], 129.76 [J(PC) ϭ 4.6 Hz] (o-, m-C of C6H5), 132.34 [J(PC) ϭ 2.7 Hz,
p-C of Mes], 134.10 [J(PC) ϭ 19.6 Hz, ipso-C of C6H5], 141.89 [J(PC) ϭ
3.0 Hz], 142.58 [J(PC) ϭ 3.2 Hz], (o-C of Mes), 144.91 [J(PC) ϭ 32.9 Hz,
ipso-C of Mes), 199.89 [J(WC) ϭ 127.6 Hz, cis-CO], 205.02 [J(WC) ϭ
134.9 Hz, trans-CO], 229.77 [J(PC) ϭ 3.9 Hz, WϭC].
Union Road, Cambridge CB2 1EZ, UK (Fax: int. code
ϩ(1223)336-033; e-mail for inquiry: fileserv@ccdc.cam.ac.uk:
e-mail for deposition: deposit@ccdc.cam.ac.uk).
Acknowledgement. Support of these investigations by the Fonds der
Chemischen Industrie and the Wacker-Chemie GmbH (gift of
chemicals) is gratefully acknowledged.
31P-NMR (CDCl3): δ ϭ Ϫ5.73.
MS (FAB, NBOH): m/z ϭ 829 (3) (Mϩ, 3 %), 717 (MϩϪ4 CO, 4 %).
References
1-N-[trans-Bis(dimethylphenylphosphane)mesitylnickelio]amino-3-
[trans-bis(dimethylphenylphosphane)mesitylnickelio]propynylidene-
(pentacarbonyl)tungsten (9): The synthesis of 9 from 1.00 mmol
(0.83 g) of 8 in 10 ml of THF was carried out similarly to the prep-
aration of 6 from 4/5. Instead of [IFe(CO)2Cp], 1.00 mmol (0.53 g)
of [BrNi(PMe2Ph)2Mes] in 5 ml of THF was employed. For chro-
matography pentane/THF (2:1) was used. Complex 9 was obtained
as a slight yellow powder.
[1] A.-M. Giroud-Godquin, P. M. Maitlis, Angew. Chem. 1991,
103, 370; Angew. Chem. Int. Ed. Engl. 1991, 30, 375.
[2] See e.g. (a) D. W. Bruce, D. O’Hare, (Eds.), Inorganic Materi-
als, Wiley, Chichester, 1992. (b) P, Wisian-Neilson, H. R.
Allcock, K. J. Wynne, (Eds.), Inorganic and Organometallic
Polymers II: Advanced Materials and Intermediates; ACS
Symp. Ser. 572, American Chemical Society, Washington, DC,
1994. (c) I. R. Whittall, A. M. McDonagh, M. G. Humphrey,
M. Samoc, Adv. Organomet. Chem. 1998, 42, 291. (d) I. R.
Whittall, A. M. McDonagh, M. G. Humphrey, M. Samoc,
Adv. Organomet. Chem. 1999, 43, 349.
[3] For recent reviews see e. g. (a) M. D. Ward, Chem. Soc. Rev.
1995, 121. (b) F. Paul, C. Lapinte, Coord. Chem. Rev. 1998,
178Ϫ180, 431. (c) P. J. Low, M. I. Bruce, Adv. Organomet.
Chem. 2001, 48, 71.
[4] Recent reviews: (a) W. Beck, B. Niemer, M. Wieser, Angew.
Chem 1993, 105, 969; Angew. Chem. Int. Ed. Engl. 1993, 32,
923. (b) H. Lang, Angew. Chem. 1994, 106, 569; Angew. Chem.
Int. Ed. Engl. 1994, 33, 547. (c) U. H. F. Bunz, Angew. Chem.
1996, 108, 1047; Angew. Chem. Int. Ed. Engl. 1996, 35, 969.
(d) T. Bartik, W. Weng, J. A. Ramsden, S. Szafert, S. B. Fal-
loon, A. M. Arif, J. A. Gladysz, J. Am. Chem. Soc. 1998, 120,
11071 and literature cited therein.
Yield 0.77 g (60 % relative to 8). Dec. at 124 °C.
Elemental analysis (for C58H67NNi2O5P4W [1283.3]) found (calc.)
[%]: C 54.43 (54.28); H 5.27 (5.26); N 1.36 (1.09).
IR (THF): ν(CO) 2047 w, 1951 w, 1906 vs, 1882 m; ν(CϵC) ϭ 2005 vw cmϪ1
.
1H NMR (CDCl3): δ ϭ 0.64 [J(PH) ϭ 3.7 Hz, 6 H, Ni1PCH3], 1.17 [J(PH) ϭ
3.3 Hz, 6 H, Ni1PCH3], 1.42 [J(PH) ϭ 3.5 Hz, 12 H, Ni2PCH3], 1.93, 2.13,
2.18, 3.12 (4 ϫ s, 4 ϫ 3 H, p-CH3 of Ni1Mes and Ni2Mes, o-CH3 of Ni1Mes),
2.29 (s, 6 H, o-CH3 of Ni2Mes), 6.35 (s, 1 H, m-H of Ni1Mes), 6.58 (s, 1 H,
m-H of Ni1Mes), 6.43 (s, 2 H, m-H of Ni2Mes), 6.99 (br. s, 1 H, NH), 7.31-
7.39 (m, 16 H, C6H5), 7.84-7.90 (m, 4 H, C6H5).
13C NMR (CDCl3, 0 °C): δ ϭ 11.37 [J(PC) ϭ 16.6 Hz, Ni1PCH3], 13.16
[J(PC) ϭ 12.4 Hz, Ni1PCH3], 15.71 [J(PC) ϭ 15.6 Hz, Ni2PCH3], 20.59 (p-
CH3 of Ni1Mes and Ni2Mes), 25.46, 26.34 (o-CH3 of Ni1Mes), 25.56 (o-CH3
of Ni2Mes), 125.55, 125.85, 126.31, 128.05, 128.51, 129.29, 129.63, 129.91
[J(PC) ϭ 4.5 Hz], 130.96, 131.51, 131.91, 132.42 [J(PC) ϭ 5.8 Hz], 133.57,
135.25 [J(PC) ϭ 19.0 Hz], 136.99 [J(PC) ϭ 20.2 Hz], 141.86, 142.48 (ipso-,
o-, m-, p-C of Ni1PC6H5 and Ni2PC6H5, o-, m-, p-C of Ni1Mes and Ni2Mes,
Cβ), 147.72 [J(PC) ϭ 33.1 Hz], 156.27 [J(PC) ϭ 32.1 Hz] (ipso-C of Ni1Mes
and Ni2Mes), 161.81 [J(PC) ϭ 32.1 Hz, Cα], 201.62 [J(WC) ϭ 128.4 Hz, cis-
CO], 205.33 (trans-CO), 232.24 (WϭC).
[5] (a) C. Hartbaum, G. Roth, H. Fischer, Chem. Ber./Recl. 1997,
130, 479. (b) C. Hartbaum, H. Fischer, Chem. Ber./Recl. 1997,
130, 1063.
[6] C. Hartbaum, H. Fischer, J. Organomet. Chem. 1999, 578, 186.
(b) C. Hartbaum, E. Mauz, G. Roth, K. Weissenbach, H.
Fischer, Organometallics 1999, 18, 2619.
31P-NMR (CDCl3): δ ϭ Ϫ6.31 (Ni1P), 0.93 (Ni2P).
MS (FAB, NBOH): m/z ϭ 1281 (11) (Mϩ, 11 %), 1253, 1225, 1197, 1169
(MϩϪn CO, n ϭ 1 Ϫ 4; 8, 15, 4, and 8 %), 1087, 1059, 1031, 1003 (MϩϪn
COϪPMe2Ph, n ϭ 2 Ϫ 5; 7, 14, 17, and 14 %).
[7] C. Hartbaum, G. Roth, H. Fischer, Eur. J. Inorg. Chem.
1998, 191.
X-ray Structural Analysis of 2
C18H15FeNO7SiW, Mr ϭ 625.10, monoclinic, space group P21/n,
[8] F. H. Allen, O. Kennard, D. G. Watson, L. Brammer, A. G.
Orpen, R. Taylor, J. Chem. Soc., Perkin Trans. II 1987, S1.
[9] M. P. Gamasa, J. Gimeno, E. Lastra, M. Lanfranchi, A. Tirip-
icchio, J. Organomet. Chem. 1991, 405, 333.
˚
˚
˚
a ϭ 11.187(10) A, b ϭ 11.085(10) A, c ϭ 19.088(13) A, β ϭ
3
90.39(9)°, V ϭ 2366.9(33) A , Z ϭ 4, dc ϭ 1.754 g cmϪ3, F(000) ϭ
˚
1200, µ ϭ 5.554 mmϪ1, 5652 collected reflections, 4514 indepen-
dent reflections (Rint ϭ 0.0372 %), a semi-empirical absorption cor-
rection from φ-scans was applied, R (wR2) ϭ 0.0461 (0.0999) for
3164 observed reflections [I > 2.0σ(I)], number of refined param-
eters 262, goodness of fit 1.077, largest difference peak/hole
[10] (a) M. Font-Bardia, J. Gonzalez-Platas, G. Müller, D. Pany-
ella, M. Rocamora, X. Solans, J. Chem. Soc., Dalton Trans.
1994, 3075. (b) S. J. Chadwell, S. J. Coles, P. G. Edwards, M.
B. Hursthouse, A. Imran, Polyhedron 1995, 14, 1057. (c) H.-F.
Klein, A. Bickelhaupt, M. Lemke, H. Sun, A. Brand, T. Jung,
C. Rohr, U. Flörke, H.-J. Haupt, Organometallics 1997, 16,
668. (d) C. M. King, R. B. King, N. K. Bhattacharyya, M. G.
Newton, J.Organomet.Chem. 2000, 600, 63. (e) See also A. L.
Spek, H. Kooijman, W. J. J. Smeets, CSD Base, Refcodes
NAVSOS and VEWRUK.
[11] J. R. Moss, B. L. Shaw, J. Chem. Soc. (A) 1966, 1793.
[12] W. P. Fehlhammer, W. A. Herrmann, K. Öfele: in Handbuch
der Präparativen Anorganischen Chemie (Ed.: G. Brauer), 3rd
ed., Vol. 3, F. Enke, Stuttgart 1981, chapter 3.
[13] G. M. Sheldrick, SHELX-93, Programs for Crystal Structure
Analysis, University of Göttingen, Göttingen (Germany),
1993.
ϩ0.942 /Ϫ1.353 e AϪ3. A single crystal (0.3 ϫ 0.3 ϫ 0.2 mm) was
˚
grown from CH2Cl2/pentane (2:3) and mounted in a glass capillary.
All data were collected on a Siemens P4 diffractometer at Ϫ30 °C
(adaptive w scan, 2.10° < 2θ < 26.99°) with a graphite mono-
˚
chromator (MoKα, λ ϭ 0.71073 A). The structures were solved by
direct methods using the SHELXTL-93 program package [12]. The
positions of the hydrogen atoms were calculated by assuming ideal
geometry, and their coordinates were refined together with those
of the attached carbon atoms as “riding model“. All other atoms
were refined anisotropically. Crystallographic data for the structure
of complex 2 have been deposited with the Cambridge Crystallo-
graphic Data Centre, CCDC-236846. Copies of the data can be
obtained free of charge on application to The Director, CCDC, 12
1868
 2004 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
zaac.wiley-vch.de
Z. Anorg. Allg. Chem. 2004, 630, 1863Ϫ1868