Phosphorus ylide-containing niobium complexes: Preparation and characterization of homo- and heteronuclear compounds with an α-keto ylide ligand

Article abstract of DOI:10.1016/S0022-328X(98)00811-0

The reactions have been studied between [{NbCl₃(dme)}_n] or [NbCl₃(dme)(RCCR′)] with a heterocycle containing α-keto stabilized phosphorus ylide, 2-TCMP=[{2-thiazolylcarbonyl}methylene]triphenylphosphorane, and these reactions give the α-keto ylide-containing niobium complexes [{NbCl₃(2-TCMP)}₂] (1) and [NbCl₃(2-TCMP)(RCCR′)], R=R′=Ph (2); R=R′=Me (3); R=R′=Et (4); R=Ph, R′=Me (5); R=Ph, R′=Et (6); R=Ph, R′=Pr (7); R=Ph, R′=SiMe₃ (8), respectively. The reactivity of 5 towards different reagents has also been investigated. Compound 5 reacts with MeLi to give, through a deprotonation process of a phenyl ring, the ortho-metallated complex [NbCl₂{NOSC₄H₂CHPPh₂(C ₆H₄)-O,N}]₂ (9), with the loss of the alkyne ligand. Furthemore, 5 reacts with [AuPPh₂R]CF₃SO₃ and AgCF₃SO₃ to give the heterometallic complexes [NbCl₃(2-TCMP)Au PPh₂R]₂ (CF₃SO₃)₂, R=Ph (10), R=C₃H₂SN (11), and [NbCl₃(2-TCMP)Ag]₂ (CF₃SO₃)₂ (12), respectively, with the loss of the alkyne ligand in each case.

Full text of DOI:10.1016/S0022-328X(98)00811-0

Journal of Organometallic Chemistry 570 (1998) 97–105
Phosphorus ylide-containing niobium complexes: preparation and
characterization of homo- and heteronuclear compounds with an
h-keto ylide ligand
A. Antin˜olo, F. Carrillo-Hermosilla, E. D´ıez-Barra, J. Ferna´ndez-Baeza, A. Lara-Sa´nchez,
A. Otero *, J. Tejeda
Departamento de Qu´ımica Inorga´nica, Orga´nica y Bioqu´ımica, Facultad de Ciencias Qu´ımicas, Uni6ersidad de Castilla-La Mancha,
Campus Uni6ersitario, 13071-Ciudad Real, Spain
Received 8 May 1998
Abstract
The reactions have been studied between [{NbCl3(dme)}n] or [NbCl3(dme)(RCꢀCR%)] with a heterocycle containing h-keto
stabilized phosphorus ylide, 2-TCMP=[{2-thiazolylcarbonyl}methylene]triphenylphosphorane, and these reactions give the
h-keto ylide-containing niobium complexes [{NbCl3(2-TCMP)}2] (1) and [NbCl3(2-TCMP)(RCꢀCR%)], R=R%=Ph (2); R=R%=
Me (3); R=R%=Et (4); R=Ph, R%=Me (5); R=Ph, R%=Et (6); R=Ph, R%=Pr (7); R=Ph, R%=SiMe3 (8), respectively. The
reactivity of 5 towards different reagents has also been investigated. Compound 5 reacts with MeLi to give, through a
deprotonation process of a phenyl ring, the ortho-metallated complex [N¸bC¹l¹2{¹N¹O¹S¹C¹4H¹2¹C¹H¹P¹P¹h¹2(Cº6H4)-O,N}]2 (9), with the loss
of the alkyne ligand. Furthemore, 5 reacts with [AuPPh2R]CF3SO3 and AgCF3SO3 to give the heterometallic complexes
[NbCl3(2-TCMP)Au PPh2R]2 (CF3SO3)2, R=Ph (10), R=C3H2SN (11), and [NbCl3(2-TCMP)Ag]2 (CF3SO3)2 (12), respectively,
with the loss of the alkyne ligand in each case. © 1998 Elsevier Science S.A. All rights reserved.
Keywords: Niobium; Phosphorus ylides; h-Keto ylide
1. Introduction
that can be rationalized in terms of the potential reso-
nance forms A–C (Chart 1).
Phosphorus ylides constitute an important class of
compound in the field of organometallic chemistry,
particularly due to their interesting applications in
metal-promoted organic syntheses [1]. The chemistry of
early transition metals and ylides is not common and is
mainly limited to cyclopentadienyl complexes and
ylides of the type R3P=CR%R%% [2], although a few
examples of oxophilic group 4 metal species containing
h-keto stabilized phosphorus ylides R3P=C(R%)COR%%
have also been described [3]. This class of ligand shows
an ambidentate character (C versus O coordination)
In the complexes reported with this type of ligand,
the chemical behavior of the h-keto stabilized phospho-
rus ylide has been clearly dominated by the C-coordina-
tion mode [4] and very few examples of O-coordinated
ylides have been described [5]. Examples of O-coordina-
tion include the aforementioned ylide-containing group
* Corresponding author. Tel.: +34 26 295326; fax: +34 26
295318; e-mail: aotero@qino-cr.uclm.es
0022-328X/98/$ - see front matter © 1998 Elsevier Science S.A. All rights reserved.
PII S0022-328X(98)00811-0

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A. Antin˜olo et al. / Journal of Organometallic Chemistry 570 (1998) 97–105
4 metal complexes. With these precedents in mind we
initiated a study of the reactivity of an h-keto ylide
containing a heterocycle, [{2-thiazolylcarbonyl}methyl-
scopic techniques. These techniques allowed us to dis-
tinguish between O-coordination and C(methine)-
coordination of the ylide ligand. The 1H-, 13C- and
31P-NMR spectra indicate that the 2-TCMP ligand is
bound through the carbonyl oxygen. The 1H-NMR
spectra (see Section 3) each show a doublet resonance
attributed to the methine proton with coupling con-
stants (2JPH) ranging from 15.0 to 16.4 Hz. In addi-
tion, the 13C{1H}-NMR spectra (see Section 3) show
the resonance attributed to the ylidic carbon as a
doublet with a coupling constant (1JPC) smaller than
that in the free ylide. For example, for compound 2
the value of the coupling constant is 105.3 Hz while
for the corresponding free ylide is 111.0 Hz. The val-
ues are in accordance with the known coupling con-
stant trend; free ylide\O-coordinated ylide\ylide
hydrohalide salt\C-coordinated ylide [7]. 31P-NMR
resonances (see Section 3) were observed to occur at
slightly lower field with respect to the free ylide. IR
spectroscopy has previously been demonstrated to be
another reliable indicator of the bonding mode of h-
keto ylides ([4]h, [5]a–c, [5]e). Bonding through the
carbonyl oxygen (where C in Chart 1 is the major
resonance contributor) leads to a decrease in the car-
bonyl stretching frequency with respect to the corre-
sponding free ylide. However, in complexes 1–8 the
IR spectra (see Section 3) show strong absorptions in
the range 1551 to 1557 cm−1, which are shifted to
higher wavenumbers than in the free ylide. This be-
havior, which could be considered surprising, may be
justified on the basis of the structure of the complexes.
Indeed, in these complexes the h-keto ylide ligand acts
as a chelate through N,O-coordination to give five-
ene]triphenylphosphorane
TCMP, toward the
NOSC4H2CHPPh3=2-
Nb(III) complexes
[{NbCl3(dme)}n] and [NbCl3(dme) (RCꢀCR%)] (dme=
1,2-dimethoxyethane). We report here the synthesis
and structural characterization of the first h-keto ylide
niobium complexes and, indeed, the first example of
this class of ligand acting in a chelating manner. In
this example chelation occurs through N,O-coordina-
tion to the metal center. In addition, new examples of
early-late heterometallic complexes of gold and silver
are also reported. Preliminary results of this work
have been published previously [6].
2. Results and discussion
Firstly, the reactions of the heterocycle-containing
h-keto ylide [{2-thiazolylcarbonyl}methylene]triphen-
ylphosphorane, NOSC4H2CHPPh3=2-TCMP, with
[{NbCl3(dme)n}] and [NbCl3(dme)(RCꢀCR%)] (dme=
1,2-dimethoxyethane) were investigated. The standard
reaction procedure involved the addition of the ligand
to a suspension of the appropriate niobium complex in
a 1:1 molar ratio at room temperature. The reaction
mixture was stirred for 20 h and gave a new solution
or suspension. The products were isolated after the
appropriate work-up procedure (see Section 3) as air-
sensitive solids corresponding to the complexes
[{NbCl3(2-TCMP)}2] (1) (Eq. 1) and [NbCl3(2-
TCMP)(RCꢀCR%)] (2–8) (Eq. 2).
Complexes 3, 4 and 6 were obtained from the corre-
sponding reactions as a mixture with complex 1, re-
sulting from the loss of the corresponding coordinated
alkyne. These compounds could, however, be isolated
in a pure state by recrystallization (see Section 3). The
different complexes were characterized by spectro-
membered metallacycles in which the O-atom is pro-
posed to be sp2 hybridized. This situation probably
favors effective y-bonding with the ylidic carbon to
give a strong C···O bond (see Chart 2). An X-ray
crystal study has previously been published [6] that
confirmed this proposal.

A. Antin˜olo et al. / Journal of Organometallic Chemistry 570 (1998) 97–105
99
Fig. 1. Proposed structures for complex 1.
The chemical shift values for complexes 2–8 appear at
ca. 240 ppm, which is a clear indication that the
number of electrons donated per alkyne is four. In this
way the role of both bonding y and yÞ orbitals in
ꢀꢀ
donating electrons is not in conflict with acceptance of
electron density from the niobium centre into the anti-
1
bonding y* orbital of the alkyne. The H- and 13C-
ꢀꢀ
NMR spectra of complexes 2–4 with symmetrical
alkynes exhibit an only one group of signals for the
substituted groups. This results can be due to either a
simple rotation of the alkyne ligand [10], or that as-
suming a six-coordinate description of the complexes
in which the alkyne occupies a single site, a static
structure (see Fig. 2) in which this site located perpen-
dicular to the equatorial plane defined by the N, O, Cl
and Nb atoms is proposed. Indeed, this last proposal
was confirmed in the X-ray crystal structure determi-
nation for 7 [6].
In addition, the different spectroscopic data indicate
the presence of only one of the two possible isomers
(cisoid and transoid) in each of these complexes (see
Chart 2). The cisoid isomer, which would appear to
be favored on steric arguments in the complexes, has
been proposed to be present both in solution and in
the solid state. In fact, as mentioned previously, this
structural situation was found for 7 by means of an
X-ray crystal structure determination [6]. The mass
spectrum of 1 indicates a binuclear formulation. The
IR spectrum of 1 shows a strong band at ca. 324
cm−1 in the region between 400 and 200 cm−1, which
has been assigned to the (Nb–Cl) terminal for a C2v
or C2h binuclear arrangement with the terminal chlo-
ride ligands in a trans disposition in an octahedral
environment for each niobium atom.
This structural geometry (see Fig. 1) has been de-
scribed [8] as more favorable in an analogous binu-
clear complex with both terminal and bridging halide
ligands. In the IR spectra of complexes 2–8, absorp-
tions of different intensities (medium to weak) located
at ca. 1680 cm−1 have been assigned to the (CꢀC)
mode of the bound alkynes. This represents a de-
crease of about 500 cm−1 from free alkyne values,
which is consistent with substantial weakening of the
triple bond on coordination. With regard to the
alkyne moiety, the 13C{1H}-NMR data for complexes
2–8 (see Section 3) indicate that this ligand behaves
as a four-electron donor. An empirical correlation be-
tween the alkyne y donation and 13C chemical shift
for the bound alkyne carbons has been observed [9].
Fig. 2. Proposed structure for complexes 2–8. Selected bond distances
(A) and angles (°) for complex 7, from a X-ray crystal structure
determination [6]: Nb–O 2.148(3), Nb–N 2.344(5), RCꢁCR% 1.288(9),
Nb–CR 2.066(6), Nb–CR% 2.026(6), O–Nb–N 72.3(1), O–Nb–Cl(2)
159.0(1), Cl(1)–Nb–Cl(3) 161.28(6), CR–Nb–CR% 36.7(2), O–C(2)–
C(1) 125.4(5).
˚
The reactivity of 5 toward different reagents has
also been considered in this study. Firstly, the reaction
with MeLi was studied. Compound 5 reacts with one
equivalent of MeLi in toluene to give, after the appro-
priate work-up procedure, the air-sensitive orange-red
crystalline
compound
¸¹¹¹¹¹¹¹¹¹¹¹¹¹º
[NbCl2{NOSC4H2CHPPh2(C6H4)-O,N}] (9) (Eq. 3).

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A. Antin˜olo et al. / Journal of Organometallic Chemistry 570 (1998) 97–105
Fig. 3. Proposed structures for complex 9.
The process takes place through deprotonation of a
assign the resonance that corresponds to the carbon
atom bound to the niobium centre of the ortho-metal-
lated ring. The 31P{1H}-NMR spectrum shows a reso-
nance at 16.05 ppm, which is attributed to the
phosphorus of the ylide. Furthermore, the (CO) ab-
sorption in the IR spectrum appears at 1560 cm−1 and
confirms, as previously discussed for 1–8, a bonding of
the ylide through the carbonyl oxygen. In addition, two
bands at 274 and 267 cm−1, which are probably due to
solid state splitting effects, were assigned to the (Nb–
Cl) terminal of a binuclear species with the terminal
chloride ligands trans in an octahedral environment for
each niobium atom [11].
The structural situation trans (Fig. 3a) implies that
the two tridentate ligands in the molecule are also
mutually trans, in a disposition where the steric hin-
drance is minimum. We have also studied the reaction
of complex 5 with different Lewis acidic coinage
cationic species, namely [AuPPh2R]CF3SO3 and
AgCF3SO3. Compound 5 reacts with one equivalent of
[AuPPh2R]CF3SO3, prepared in situ from AuCl(PPh2R)
and AgCF3SO3, or AgCF3SO3 to give, after appropri-
ate work-up, the corresponding heterometallic com-
plexes [NbCl3(2-TCMP)AuPPh2R]2(CF3SO3)2, R=Ph
(10), R=C3H2SN (11), and [NbCl3(2-TCMP)Ag]2
(CF3SO3)2 (12), respectively (Eq. 4 and 5).
phenyl ring in the ylide ligand to give the ortho-metal-
lated complex 9 with the loss of the coordinated alkyne.
The aim of the reaction was to prepare a methyl-con-
taining derivative, but the reaction conditions resulted
in a deprotonation process of a phenyl ring-containing
ylide to give a new tridentate anionic ligand. Alterna-
tively, the mechanism for the formation of 9 could be
methyl substitution at metal followed by |- bond
metathesis to yield the ortho-metallated product. The
complex was characterized spectroscopically. The mass
spectrum of this compound indicates a binuclear for-
mulation (see Section 3).
In the 1H-NMR spectrum the doublet due to the
methine proton is observed at a higher field than that in
both complex 5 and the free ylide. In the 13C{1H}-
NMR spectrum the resonance attributed to the ylidic
1
carbon shows a coupling constant JPC of 110.8 Hz,
which confirms an O-coordination of the ylide ligand.
In the 13C{1H}-NMR spectrum, the region in which the
resonances corresponding to the phenyl rings occur is
more complex than the corresponding area in 5 and in
the free ylide. The assignment of the different signals
was carried out on the basis of both their intensity and
values of their coupling constants JPC (see Section 3).
Using of this method it was possible to tentatively

A. Antin˜olo et al. / Journal of Organometallic Chemistry 570 (1998) 97–105
101
Fig. 4. Proposed structures for complexes 10–12.
Niobium-coinage cation heterometallic complexes
have not been widely reported in the literature and in
these compounds the hydride ligand is frequently
present as an ancillary ligand [12]. The different iso-
lated heterometallic complexes were characterized
spectroscopically. Their mass spectra (see Section 3)
indicate a binuclear formulation as the result of the
NMR spectrum of 12 exhibits a pseudotriplet, which
corresponds to two overlapped doublets by coupling
with 107Ag and 109Ag isotopes. Attempts to resolve the
complex signal by lowering the temperature (down to
−90°C) were unsuccessful. Finally, the 19F{1H}-NMR
spectra of complexes 10–12 show a signal at −74.4
ppm, which corresponds to the CF3SO3 anion. The
(CO) absorption in the IR spectra appears at ca.
1565 cm−1, indicating a bonding of the pseudophos-
phonium group through the carbonyl oxygen. The IR
spectra also show a strong band at ca. 330 cm−1 in
the region between 400 and 200 cm−1, which was
assigned to the (Nb–Cl) terminal for a C2v or C2h
binuclear disposition [8], as was previously discussed
for complex 1, with the terminal chloride ligands trans
in an octahedral environment for each niobium atom
(Fig. 4).
In conclusion, the synthesis and characterization of
the first h-keto ylide-containing niobium complexes
have been described. In addition, the reactivity of one
of these complexes toward MeLi and different Lewis
acidic coinage cationic species was studied. This work
led to the isolation and characterization new ortho-
metallated and several heterometallic derivatives.
1
loss of the coordinated alkyne ligand. In the H-NMR
spectra of complexes 10–12 the doublet due to the
methine proton occurs at chemical shift values (see
Section 3) that are intermediate between those corre-
sponding to the free ylide (5.00 ppm) and the phos-
phonium salt (6.65 ppm). These results indicate a
probable coordination of the AuPPh2R+ and Ag+
fragments to the ylidic carbon atom. In fact, the
isolobal analogy suggested between the ‘AuPR3’ and
‘H’ fragments [13], which has recently stimulated the
synthesis and study of gold-containing heterometallic
derivatives [14], would justify the formation of the
corresponding pseudophosphonium salt coordinated to
the niobium center in these reactions. Furthermore,
2
the values of the JPH coupling constants are close to
the value for the phosphonium salt (2JPH=13.5Hz). In
addition, the signal due to Hc (Hh with respect to the
S atom; see Eq. 1) in the thiazolyl ring in the different
complexes 10–12 was found to be clearly deshielded in
relation to the equivalent proton observed in complex
5. This suggests that a possible coordination of the
sulfur atom to the niobium center could be occuring.
In the 13C{1H}-NMR spectra for 10–12 (see Section
3) the resonances attributed to the ylidic carbon atoms
appear at chemical shift values close to those found
for the corresponding carbon atom in the phospho-
nium salt (35.80 ppm). The assignment of all the car-
bon resonances in the spectra was carried out by
means of the appropriate 13C-1H heteronuclear corre-
lations (HETCOR). The 31P{1H}-NMR spectra of 10
and 11 show two signals for the two different phos-
phorus atoms that are present in each molecule. The
resonances of these phosphorus centers were assigned
(see Section 3) by an HMQC 31P-1H experiment and it
was found that the more shielded signal, close to the
value found for the phosphonium salt, corresponds to
the phosphorus atom of the ylide ligand. The 31P{1H}-
3. Experimental
3.1. General
All reactions were performed using standard
Schlenk-tube techniques in an atmosphere of dry ni-
trogen. Solvents were distilled from appropriate drying
agents and degassed before use. Microanalyses were
carried out with a Perkin-Elmer 2400 CHN analyser.
Infrared spectra were obtained in the region 200–4000
cm−1 using a Perkin-Elmer 883 spectrophotometer.
1H- and 13C-NMR spectra were recorded on Varian-
Unity FT-300 and Gemini FT-200 spectrometers and
the chemical shifts were determined by reference to the
residual deuterated solvent peaks. The complexes
[{NbCl3(dme)}n],
[NbCl3(dme)(RCꢀCR%)]
and
[AuCl(PPh3)] were prepared as reported previously
[15,16].

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A. Antin˜olo et al. / Journal of Organometallic Chemistry 570 (1998) 97–105
3.2. Preparation of PPh2(C3H2SN)
(s, Cb), 123.20 (s, Cc), 120.81 [d, 1JPC=92.3 Hz,
2
Ci(PPh3)], 129.70[d, JPC=12.8 Hz, Co(PPh3)], 133.41
3
4
A suspension of 2-bromothiazole (13.23 g, 0.08 mol)
in toluene (40 cm3) was cooled to −70°C and a solu-
tion of n-BuLi in hexane (1.6 M, 53 cm3, 0.08 mol) and
(C6H5)2PCl (14 cm3, 0.08 mol) were added with vigor-
ous stirring. The cooling bath was kept at −70°C for 1
h, and then allowed to slowly reach room temperature.
After 20 h the mixture was filtered through Celite, and
the solvent was removed in vacuo to give a yellow oil.
(Yield 75%).
[d, JPC=10.7 Hz, Cm(PPh3)], 133,80[d, JPC=3.0 Hz,
Cp(PPh3)], 139.42 [s, Ci(PhCꢀ)], 126.65 [s, Co(PhCꢀ)],
129.31 [s, Cm(PhCꢀ)], 128.31 [s Cp(PhCꢀ)], 240.20 (s,
CꢀC); 31P-{1H}(CDCl3, H3PO4 as reference), l 18.69 (s,
PPh3). IR (Nujol): 1553 [w(CꢁO)], 1692 [w(CꢀC)], 382
and 309 [w(Nb–Cl)]cm−1. (Found: C, 58.4; H, 4.3; N,
2.0. Anal. Calc. for C37H28NbCl3NOPS: C, 58.0; H, 3.8;
N, 1.8).
3.6. Preparation of [NbCl3(2-TCMP)(MeCꢀCMe)] (3)
3.3. Preparation of AuClPPh2(C3H2SN)
To a suspension of [NbCl3(dme)(MeCꢀCMe)] (222
mg, 0.640 mmol) in THF (20 cm3), an equimolar quan-
tity of 2-TCMP (248 mg, 0.640 mmol) was added. The
suspension was stirred at room temperature for 20 h.
The solvent was removed in vacuo to give a brown
solid as a mixture of 1 and 3. Compound 3 was isolated
by crystallization from CH2Cl2/Et2O. (Yield 60%).
To a suspension of AuCl (tht) (1 g, 3 mmol) in
acetone (20 cm3), an equimolar quantity of
PPh2(C3H2SN) (840 mg, 3 mmol) was added. The sus-
pension was stirred at room temperature for 1 h. The
solvent was removed in vacuo and a greenish-yellow
solid was obtained. (Yield 90%).
1
2
NMR: H(CDCl3), l 5.15 (d, JPH=16.4 Hz, CH), 8.48
(d, 3JHH=3.2 Hz, Hb), 7.55 (d, 3JHH=3.2 Hz, Hc),
7.56–7.72 (m, 15H, PPh3), 2.56 (s, 6H, CH3Cꢀ); 13C-
3.4. Preparation of [{NbCl3(2-TCMP)}2] (1)
1
To a suspension of [{NbCl3(dme)}] (240 mg, 0.820
mmol) in THF (20 cm3), an equimolar quantity of
2-TCMP (321 mg, 0.820 mmol) was added. The suspen-
sion was stirred at room temperature for 20 h. The
solvent was removed in vacuo and a greenish-brown
{1H}(CDCl3), l 72.40 (d, JPC=105.3 Hz CH), 165.00
2
(d, JPC=18.0 Hz, CO), 171.70 (s, Ca), 142.70 (s, Cb),
123.55 (s, Cc), 121.81 [d, 1JPC=92.7 Hz, Ci(PPh3)],
2
3
129.84 [d, JPC=13.2 Hz, Co(PPh3)], 133.36 [d, JPC
=
11.1 Hz, Cm(PPh3)], 133,97 [d, 4JPC=3.0 Hz, Cp(PPh3)],
25.59 (s, CH3Cꢀ), 246.81 (s, CꢀC); 31P-{1H}(CDCl3,
H3PO4 as reference), l 19.00 (s, PPh3). IR (Nujol): 1552
1
solid was obtained. (Yield 80%). NMR: H(CDCl3), l
2
3
5.40 (d, JPH=16.0 Hz, CH), 8.20 (d, JHH=5.7 Hz,
3
Hb), 7.60 (d, JHH=5.7 Hz, Hc), 7.40–7.61 (m, 30H,
[w(CꢁO)], 1680 [w(CꢀC)], 377 and 323 [w(Nb–Cl)]cm−1
.
PPh3); 13C-{1H}(CDCl3), l 71.50 (d, JPC=101.0 Hz,
(Found: C, 50.5; H, 4.1; N, 2.2. Anal. Calc. for
C27H24NbCl3NOPS: C, 50.5; H, 3.9; N, 2.2).
1
CH), 144.30 (s, CO), 168.30 (s, Ca), 142.80 (s, Cb),
124.40 (s, Cc), 120.36 [d, 1JPC=92.7 Hz, Ci(PPh3)],
2
3
130.11 [d, JPC=13.2 Hz, Co(PPh3)], 133.45 [d, JPC
=
3.7. Preparation of [NbCl3(2-TCMP)(EtCꢀCEt)] (4)
11.1 Hz, Cm(PPh3)], 134,48 [d, 4JPC=3.0 Hz, Cp(PPh3)];
31P-{1H}(CDCl3, H3PO4 as reference), l 18.88 (s, PPh3).
To a suspension of [NbCl3(dme)(EtCꢀCEt)] (210 mg,
0.560 mmol) in THF (20 cm3) was added an equimolar
quantity of 2-TCMP (219 mg, 0.560 mmol). The sus-
pension was stirred at room temperature for 20 h. The
solvent was removed in vacuo to give an orange solid as
a mixture of 1 and 4. Compound 4 was isolated by
crystallization from CH2Cl2/Et2O. (Yield 55%). NMR:
IR (Nujol): 1553 [w(CꢁO)], 324 [w(Nb–Cl)]cm−1
.
(Found: C, 46.7; H, 3.2; N, 2.5. Anal. Calc. for
C46H36Nb2Cl6N2O2P2S2: C, 47.0; H, 3.1; N, 2.3). Mass
spectrum: (m/z assignment, % intensity): 1175D [M+
1], 6, 1088D [M–C3H2NS], 5, 971D [M–2 (C3H2NS)],
15, 388D [(2-TCMP)], 100.
2
1H(CDCl3), l 5.09 (d, JPH=15.4 Hz, CH), 8.65 (d,
3
3.5. Preparation of [NbCl3(2-TCMP)(PhCꢀCPh)] (2)
3JHH=7.3 Hz, Hb), 7.13 (d, JHH=3.2 Hz, Hc), 7.55–
7.77 (m, 15H, PPh3), 2.96 (q, 4H, 3JHH=3.2 Hz,
To a suspension of [NbCl3(dme)(PhCꢀCPh)] (100 mg,
0.210 mmol) in THF (20 cm3) was added an equimolar
quantity of 2-TCMP (81 mg, 0.210 mmol). The suspen-
sion was stirred at room temperature for 20 h. The
solvent was removed in vacuo to give a brown solid.
CH3CH2Cꢀ), 0.97 (t, 6H, 3JHH=7.3 Hz,
1
CH3CH2Cꢀ); 13C-{1H}(CDCl3), l 71.30 (d, JPC
=
2
105.6 Hz, CH), 165.30 (d, JPC=18.0 Hz, CO), 171.80
1
(s, Ca), 142.70 (s, Cb), 123.24 (s, Cc), 121.55 [d, JPC
=
2
92.7 Hz, Ci(PPh3)], 129.85[d, JPC=13.2 Hz, Co(PPh3)],
1
2
3
4
(Yield 80%). NMR: H(CDCl3), l 5.15 (d, JPH=15.0
133.44 [d, JPC=11.1 Hz, Cm(PPh3)], 133,97 [d, JPC=
3
3
Hz, CH), 8.50 (d, JHH=3.4 Hz, Hb), 7.56 (d, JHH
=
3.0 Hz, Cp(PPh3)], 30.46 (s, CH3CH2Cꢀ), 13.58 (s,
CH3CH2Cꢀ), 250.30 (s, CꢀC); 31P-{1H}(CDCl3,
H3PO4 as reference), l 18.98 (s, PPh3). IR (Nujol): 1551
[w(CꢁO)], 1700 [w(CꢀC)], 380 and 322 [w(Nb–
3.4 Hz, Hc), 7.40–7.80 (m, 25H, PPh3 and PhCꢀ);
13C-{1H}(CDCl3), l 72.64 (d, 1JPC=105.3 Hz, CH),
2
165.20 (d, JPC=19.0 Hz, CO), 171.00 (s, Ca), 142.80

A. Antin˜olo et al. / Journal of Organometallic Chemistry 570 (1998) 97–105
103
Cl)]cm−1. (Found: C, 52.0; H, 4.0; N, 1.6. Anal. Calc.
for C29H10NbCl3NOPS: C, 51.9; H, 4.4; N, 2.0).
3.10. Preparation of [NbCl3(2-TCMP)(PhCꢀCPr)] (7)
To a suspension of [NbCl3(dme)(PhCꢀCPr)] (174
mg, 0.400 mmol) in THF (20 cm3), an equimolar quan-
tity of 2-TCMP (155 mg, 0.400 mmol) was added. The
suspension was stirred at room temperature for 20 h.
The solvent was removed in vacuo to give a brown
3.8. Preparation of [NbCl3(2-TCMP)(PhCꢀCMe)] (5)
To a suspension of [NbCl3(dme)(PhCꢀCMe)] (260
mg, 0.640 mmol) in THF (20 cm3), an equimolar
quantity of 2-TCMP (248 mg, 0.640 mmol) was
added. The suspension was stirred at room tempera-
ture for 20 h. The solvent was removed in vacuo to
solid. (Yield 86%). NMR: 1H(CDCl3), l 5.10 (d, 2JPH
=
16.1 Hz, CH), 8.57 (d, 3JHH=2.9 Hz, Hb), 7.57 (d,
3JHH=2.9 Hz, Hc), 7.46–7.69 (m, 20H, PPh3 and
PhCꢀ), 3.19 (t, 2H, 3JHH=7.6 Hz, ꢀCCH2CH2CH3),
1
give an orange solid. (Yield 85%). NMR: H(CDCl3),
3
1.50 (m, 2H, ꢀCCH2CH2CH3), 0.69 (t, 3H, JHH=7.6
2
3
l 5.10 (d, JPH=16.1 Hz, CH), 8.55 (d, JHH=3.1 Hz,
Hz, ꢀCCH2CH2CH3); 13C-{1H}(CDCl3), l 71.53 (d,
3
Hb), 7.58 (d, JHH=3.1 Hz, Hc), 7.40–7.80 (m, 20H,
2
1JPC=105.0 Hz, CH), 165.20 (d, JPC=19.0 Hz, CO),
PPh3 and PhCꢀ), 2.79 (s, 3H, ꢀCCH3); 13C-
171.00 (s, Ca), 142.80 (s, Cb), 123.20 (s, Cc), 120.79 [d,
{1H}(CDCl3), l 71.80 (d, JPC=104.6 Hz, CH), 165.10
1
1JPC=92.7 Hz, Ci(PPh3)], 129.79 [d, 2JPC=12.8 Hz,
2
(d, JPC=18.4 Hz, CO), 170.90 (s, Ca), 142.70 (s, Cb),
3
Co(PPh3)], 133.35 [d, JPC=11.4 Hz, Cm(PPh3)], 133,88
123.33 (s, Cc), 121.22 [d, 1JPC=92.7 Hz, Ci(PPh3)],
129.80 [d, 2JPC=13.2 Hz, Co(PPh3)], 133.36 [d,
3JPC=10.7 Hz, Cm(PPh3)], 133,90 [d, 4JPC=2.9 Hz,
Cp(PPh3)], 138.06 [s, Ci(PhCꢀ)], 127.87 [s, Co(PhCꢀ
)], 131.02 [s, Cm(PhCꢀ)], 128.67 [s Cp(PhCꢀ)],
22.42 (s, ꢀCCH3), 251.97, 236.24 (s, CꢀC); 31P-
{1H}(CDCl3, H3PO4 as reference), l 19.06 (s, PPh3).
IR (Nujol): 1554 [w(CꢁO)], 1680 [w(CꢀC)], 379 and
313 [w(Nb–Cl)]cm−1. (Found: C, 54.3; H, 4.0; N, 1.8.
Anal. Calc. for C32H26NbCl3NOPS: C, 54.7; H, 3.7; N,
1.9).
[d, 4JPC=3.0 Hz, Cp(PPh3)], 139.01 [s, Ci(PhCꢀ)],
127.62 [s, Co(PhCꢀ)], 130.42 [s, Cm(PhCꢀ)], 128.10 [s
Cp(PhCꢀ)], 39.68 (s, ꢀCCH2CH2CH3), 21.29 (s, ꢀ
CCH2CH2CH3), 14.52 (s, ꢀCCH2CH2CH3), 253.38,
237.17 (s, CꢀC); 31P-{1H}(CDCl3, H3PO4 as refer-
ence), l 18.95 (s, PPh3). IR (Nujol): 1556 [w(CꢁO)],
1692 [w(CꢀC)], 378 and 311 [w(Nb–Cl)]cm−1. (Found:
C, 55.4; H, 4.7; N, 2.1. Anal. Calc. for
C34H30NbCl3NOPS: C, 55.8; H, 4.2; N, 1.9).
3.11. Preparation of [NbCl3(2-TCMP)(PhCꢀCSiMe3)]
(8)
3.9. Preparation of [NbCl3(2-TCMP)(PhCꢀCEt)] (6)
To a suspension of [NbCl3(dme)(PhCꢀCSiMe3)] (200
mg, 0.430 mmol) in THF (20 cm3) was added an
equimolar quantity of 2-TCMP (167 mg, 0.430 mmol).
The suspension was stirred at room temperature for 20
h. The solvent was removed in vacuo to give a brown
To a suspension of [NbCl3(dme)(PhCꢀCEt)] (270
mg, 0.640 mmol) in THF (20 cm3), an equimolar
quantity of 2-TCMP (246 mg, 0.640 mmol) was added.
The suspension was stirred at room temperature for
20 h. The solvent was removed in vacuo to give an
orange solid as a mixture of 1 and 6. Compound 6
was isolated by crystallization from CH2Cl2/Et2O.
solid. (Yield 75%). NMR: 1H(CDCl3), l 5.11 (d, 2JPH
=
15.6 Hz, CH), 8.58 (d, 3JHH=2.8 Hz, Hb), 7.61 (d,
3JHH=2.8 Hz, Hc), 7.50–7.98 (m, 20H, PPh3 and
PhCꢀ), 0.30 (s, 9H, ꢀCSiMe3); 13C-{1H}(CDCl3), l
1
2
(Yield 62%). NMR: H(CDCl3), l 5.16 (d, JPH=16.0
1
2
71.80 (d, JPC=105.6 Hz, CH), 165.40 (d, JPC=18.0
3
3
Hz, CH), 8.55 (d, JHH=3.0 Hz, Hb), 7.55 (d, JHH
=
Hz, CO), 171.70 (s, Ca), 142.60 (s, Cb), 123.32 (s, Cc),
3.0 Hz, Hc), 7.40–7.80 (m, 20H, PPh3 and PhCꢀ), 3.17
(q, 2H, 3JHH=7.5 Hz, ꢀCCH2CH3), 1.10 (t, 3H,
3JHH=7.3 Hz, ꢀCCH2CH3); 13C-{1H}(CDCl3), l
1
2
120.58 [d, JPC=92.3 Hz, Ci(PPh3)], 129.70 [d, JPC
=
13.3 Hz, Co(PPh3)], 133.23 [d, 3JPC=11.1 Hz,
Cm(PPh3)], 134.31 [d, JPC=2.9 Hz, Cp(PPh3)], 139.56
4
1
2
71.90 (d, JPC=104.8 Hz, CH), 165.22 (d, JPC=19.0
[s, Ci(PhCꢀ)], 127.37 [s, Co(PhCꢀ)], 131.89 [s,
Cm(PhCꢀ)], 128.74 [s Cp(PhCꢀ)], 0.04 (s, ꢀCSiMe3),
260.40, 244.87 (s, CꢀC); 31P-{1H}(CDCl3, H3PO4 as
reference), l 18.65 (s, PPh3). IR (Nujol): 1551 [w(CꢁO)],
1653 [w(CꢀC)], 381 and 305 [w(Nb–Cl)]cm−1. (Found:
C, 53.4; H, 4.2; N, 2.0. Anal. Calc. for
C34H42NbCl3NOPSSi: C, 53.7; H, 4.1; N, 1.8).
Hz, CO), 170.80 (s, Ca), 142.50 (s, Cb), 123.50 (s, Cc),
1
2
120.59 [d, JPC=92.7 Hz, Ci(PPh3)], 129.75 [d, JPC
=
13.3 Hz, Co(PPh3)], 133.31 [d, 3JPC=10.7 Hz,
Cm(PPh3)], 133,87 [d, JPC=2.9 Hz, Cp(PPh3)], 138.50
4
[s, Ci(PhCꢀ)], 127.65 [s, Co(PhCꢀ)], 130.73[s,
Cm(PhCꢀ)], 128.65 [s Cp(PhCꢀ)], 30.88 (s,
ꢀ
CCH2CH3), 12.58 (s, ꢀCCH2CH3), 254.66, 236.75 (s,
CꢀC); 31P-{1H}(CDCl3, H3PO4 as reference), l 18.98
(s, PPh3). IR (Nujol): 1557 [w(C=O)], 1692 [w(CꢀC)],
377 and 298 [w(Nb–Cl)]cm−1. (Found: C, 55.8; H, 4.2;
N, 1.6. Anal. Calc. for C33H28NbCl3NOPS: C, 55.2; H,
3.9; N, 1.9).
3.12. Preparation of
[N¸bC¹l¹2{¹N¹O¹S¹C¹4H¹¹2C¹H¹P¹P¹h¹2(ºC6H4)-O,N}]2 (9)
A suspension of [NbCl3(2-TCMP)(PhCꢀCMe)] (5)
(250 mg, 0.356 mmol) in toluene (40 cm3) was cooled to

104
A. Antin˜olo et al. / Journal of Organometallic Chemistry 570 (1998) 97–105
3.14. Preparation of
[NbCl3(2-TCMP){AuPPh2(C3H2SN)}]2(CF3SO3)2 (11)
−40°C and an ethereal solution of CH3Li (1.6 m, 0.24
cm3, 0.384 mmol) was added with vigorous stirring. The
cooling bath was kept a −40°C for 1 h and then
allowed to slowly reach room temperature. After 20 h
the mixture was filtered through Celite, and the solvent
was removed in vacuo to give a orange-red solid. (Yield
75%). NMR: 1H(CDCl3), l 4.68 (d, 2JPH=19.5 Hz,
To a suspension of [NbCl3(2-TCMP)(PhCꢀCMe)]
(5) (235 mg, 0.334 mmol) in toluene (40 cm3), an
equimolar quantity of [AuPPh2(C3H2SN)](CF3SO3)
(206 mg, 0.334 mmol) in dichoromethane (30 cm3) was
added. The suspension was stirred at room temperature
for 20 h. The solvent was removed in vacuo to give a
3
3
CH), 7.51 (d, JHH=3.2 Hz, Hb), 7.37 (d, JHH=3.2
Hz, Hc), 7.40–7.70 [m, 28H, PPh2(C6H4)]; 13C-
1
1
{1H}(CDCl3), l 62.63 (d, JPC=110.8 Hz, CH), 169.70
brown solid. (Yield 70%). NMR: H(CDCl3), l 5.73 (d,
2JPH=13.4 Hz, CH), 8.33 (d, JHH=3.8 Hz, Hb), 7.78
3
2
(d, JPC=21.1 Hz, CO), 173.74 (s, Ca), 142.50 (s, Cb),
(d, 3JHH=2.9 Hz, Hc), 8.01 [d, 3JHH=2.9 Hz,
121.69 (s, Cc), 123.51 [d, 1JPC=92.1 Hz, Ci(PPh2)],
Hb{PPh2(C3H2SN)},
7.80
[d,
3JHH=2.9
Hz,
2
3
129.82 [d, JPC=12.6 Hz, Co(PPh2)], 133.31 [d, JPC
=
10.3 Hz, Cm(PPh2)], 133.42 [d, 4JPC=3.1 Hz, Cp(PPh2)],
Hc{PPh2(C3H2SN)}, 7.44–7.85 [m, 50 H, PPh3 and
PPh2(C3H2SN)]; 13C-{1H}(CDCl3), l 34.53 (d, JPC
=
1
1
2
128.41 [d, JPC=71.0 Hz, C1(C6H4)], 138.83 [d, JPC
=
11.0 Hz, C2(C6H4)], 132.42 [d, 3JPC=10.6 Hz,
57.7 Hz, CH), 177.28 (s, CO), 183.94 (s, Ca), 145.38 (s,
1
4
Cb), 129.04 (s, Cc), 117.80 [d, JPC=88.9 Hz, Ci(PPh3)],
C3(C6H4)], 132.74 [d, JPC=3.0 Hz, C4(C6H4)], 130.61
2
3
130.35 [d, JPC=13.3 Hz, Co(PPh3)], 133.80 [d, JPC
=
[d, 3JPC=11.0 Hz, C5(C6H4)], 128.82 [d, 2JPC=12.6
Hz, C6(C6H4)]; 31P-{1H}(CDCl3, H3PO4 as reference), l
16.05 [s, PPh2(C6H4)]. IR (Nujol): 1560 [w(CꢁO)], 274
and 267 [w(Nb–Cl)]cm−1. (Found: C, 50.8; H, 3.0; N,
2.3. Calcd. for C46H34Nb2Cl4N2O2P2S2: C, 50.2; H, 3.1;
N, 2.5). Mass spectrum (m/z assignment, % intensity):
1086 D [M–C3H2NS], 7; 971 D [M–2C3H2NS], 12; 800
D [M-OCHCPPh3], 15; 388 D [(2-TCMP)], 100.
10.7 Hz, Cm(PPh3)], 135.22 [d, 4JPC=3.4 Hz, Cp(PPh3)],
1
164.28 [d, JPC=41.5 Hz, Ca{PPh2(C3H2SN)}], 134.08
[d, 3JPC=10.7 Hz, Cb{PPh2(C3H2SN)}], 126.01 [s,
Cc{PPh2(C3H2SN)}], 130.50 [d, 1JPC=30.3 Hz,
Ci{PPh2(C3H2SN)}], 134.00 [d, 2JPC=19.1 Hz,
Co{PPh2(C3H2SN)], 129.60 [d, 3JPC=10.3 Hz,
Cm{PPh2(C3H2SN)}], 132.10 [d, 4JPC=2.0 Hz,
Cp{PPh2(C3H2SN)}]; 31P-{1H}(CDCl3, H3PO4 as refer-
ence), l 21.68 (s, PPh3), 23.01 [s, {PPh2(C3H2SN)}];
19F(CDCl3, CFCl3 as reference) l −79.49 (s, CF3SO3);
3.13. Preparation of
[NbCl3(2-TCMP)(AuPPh3)]2(CF3SO3)2 (10)
IR (Nujol): 1568 [w(CꢁO)], 328 [w(Nb–Cl)]cm−1
.
(Found: C, 38.4; H, 2.8; N, 2.2. Anal. Calc. for
C78H60Nb2Au2Cl6F6N4O8P4S6: C, 38.9; H, 2.5; N, 2.3).
Mass spectrum (m/z assignment, % intensity): 1566 D
To a suspension of [NbCl3(2-TCMP)(PhCꢀCMe)] (5)
(235 mg, 0.334 mmol) in toluene (40 cm3), an equimolar
quantity of [AuPPh3](CF3SO3) (204 mg, 0.334 mmol) in
dichloromethane (30 cm3) was added. The suspension
was stirred at room temperature for 20 h. The solvent
was removed in vacuo to give an orange solid. (Yield
75%). NMR: 1H(CDCl3), l 5.78 (d, 2JPH=13.1 Hz,
[M+ –2{PPh2(C3H2SN)}], 5; 735
D
[Au{PPh2-
(C3H2SN)}2]+, 20; 466
35; 388 D [(2-TCMP)], 100.
D
[Au{PPh2(C3H2SN)}]+,
3.15. Preparation of [NbCl3(2-TCMP)Ag]2(CF3SO3)2
(12)
3
3
CH), 8.04 (d, JHH=2.7 Hz, Hb), 7.73 (d, JHH=2.7
Hz, Hc), 7.44–7.86 (m, 60 H, PPh3 and AuPPh3);
13C-{1H}(CDCl3), l 34.99 (d, 1JPC=67.5 Hz, CH),
179.13 (s, CO), 183.90 (s, Ca), 145.51 (s, Cb), 129.18 (s,
To a suspension of [NbCl3(2-TCMP)(PhCꢀCMe)]
(5) (200 mg, 0.284 mmol) in acetone (40 cm3), an
equimolar quantity of AgCF3SO3 (73 mg, 0.284 mmol)
was added. The suspension was stirred at room temper-
ature for 1 h. The solvent was removed in vacuo to give
1
Cc), 117.90, 117.72 [d, JPC=87.5, 88.8 Hz, Ci(PPh3 or
AuPPh3)], 130.51, 130.42 [d, 2JPC=13.2, 12.7 Hz,
Co(PPh3 or AuPPh3)], 134.01, 133.83 [d, 3JPC=10.3,
10.7 Hz, Cm(PPh3 or AuPPh3)], 135.32, 135.22 [d,
4JPC=3.1, 2.5 Hz, Cp(PPh3 or AuPPh3)]; 31P-
{1H}(CDCl3, H3PO4 as reference), l 21.69 (s, PPh3),
23.08 (s, AuPPh3); 19F(CDCl3, CFCl3 as reference) l
−79.40 (s, CF3SO3); IR (Nujol): 1562 [w(CꢁO)], 326
[w(Nb–Cl)]cm–1. (Found: C, 42.3; H, 2.8; N, 1.3. Anal.
Calc. for C84H66Nb2Au2Cl6F6N2O8P4S4: C, 42.2; H, 3.0;
N, 1.4). Mass spectrum (m/z assignment, % intensity):
1
a red solid. (Yield 50%). NMR: H(CDCl3), l 5.87 (d,
3
2JPH=13.2 Hz, CH), 8.15 (d, JHH=2.9 Hz, Hb), 7.97
(d, 3JHH=2.9 Hz, Hc), 7.42–7.75 (m, 30H, PPh3);
13C-{1H}(CDCl3), l 35.11 (d, 1JPC=59.4 Hz, CH),
2
164.47 (d, JPC=14.2 Hz, CO), 182.96 (s, Ca), 144.35
(s, Cb), 129.17 (s, Cc), 118.00 [d, 1JPC=89.1 Hz,
2
Ci(PPh2)], 130.35 [d, JPC=13.6 Hz, Co(PPh2)], 133.85
3
4
[d, JPC=11.0 Hz, Cm(PPh2)], 135.22 [d, JPC=3.1 Hz,
1572
C3H2NS], 9; 721
D D
[M+ –2PPh3], 5; 1417 [M+ –2PPh3–
Cp(PPh2)]; 31P-{1H}(CDCl3, H3PO4 as reference), l
21.15, 21.10 (dd, J107AgP=6.7 Hz or J109AgP=6.1 Hz,
PPh3). IR (Nujol): 1560 [w(CꢁO)], 335 [w(Nb–Cl)]cm−1
(Found: C, 33.9; H, 2.0; N, 1.8. Anal. Calc. for
D
[Au(PPh3)2]+, 42; 459
D
2
2
[Au(PPh3)]+, 40; 388 D [(2-TCMP)], 6; 303 D [(2-
TCMP)–C3H2NS], 100.
.

A. Antin˜olo et al. / Journal of Organometallic Chemistry 570 (1998) 97–105
105
M. Calligaris, G. Nardin, M. Mari, J. Chem. Soc. Dalton Trans.
(1987) 1381. (h) J.A. Albanese, A.L. Rheingold, J.L. Burmeister,
Inorg. Chim. Acta. 150 (1988) 213. (i) J. Vicente, M.T. Chicote,
J. Ferna´ndez-Baeza, Organomet. Chem. 364 (1989) 407. (j) G.
Facchin, R. Bertani, L. Zanotto, M. Calligaris, G. Nardin, J.
Organomet. Chem. 366 (1989) 409. (k) J. Vicente, M.T. Chicote,
M.C. Lagunas, P.G. Jones, J. Chem. Soc. Dalton Trans. (1991)
2579. (l) M. Kalyanasundari, K. Panchanatheswaran, W.T.
Robinson, H. Wen, J. Organomet. Chem. 491 (1995) 103.
[5] (a) J. Buckle, P.G. Harrison, T.J. King, J.A. Richards, J. Chem.
Soc. Chem. Commun. (1972) 1104. (b) J. Buckle, P.G. Harrison,
J. Organomet. Chem. 49 (1973) 617. (c) I. Kawafune, G. Mat-
subayashi, Inorg. Chim. Acta. 70 (1983) 1. (d) R. Uso´n, J.
Fornies, R. Navarro, P. Espinet, C. Mendivil, J. Organomet.
Chem. 290 (1985) 125. (e) L.R. Falvello, S. Ferna´ndez, R.
Navarro, E.P. Urriolabeitia, Inorg. Chem. 35 (1996) 3064. (f)
L.R. Falvello, S. Ferna´ndez, R. Navarro, I. Pascual, E.P. Urrio-
labeitia, J. Chem. Soc. Dalton Trans. (1997) 763.
C48H36Nb2Ag2Cl6F6N2O8P2S4: C, 34.1; H, 1.6; N, 2.1).
Mass spectrum (m/z assignment, % intensity): 1309D
[M+ –C3H2SN], 7; 667D [12M+ –Cl], 15; 388 D [(2-
TCMP)], 100; 370 D [AgPPh3]+, 20.
Acknowledgements
The authors gratefully acknowledge financial support
from the Direccio´n General de Ense´nanza Superior/e/
Investigacio´n (DGES) (Grant. No. PB-95-0023-C01) of
Spain.
References
[6] E. D´ıez-Barra, J. Ferna´ndez-Baeza, M.M. Kubicki, A. Lara-
Sa´nchez, A. Otero, N. Poujaud, J. Tejeda, J. Organomet. Chem.
542 (1997) 291.
[7] R. Uso´n, J. Fornie´s, R. Navarro, P. Espinet, C. Mendivil, J.
Organomet. Chem. 290 (1985) 125.
[1] A.W. Johnson, W.C. Kaska, K.A.O. Starzewski, D.A. Dixon,
Ylides and Imines of Phosphorus, Wiley, New York, 1993, Ch.
14 and references cited therein.
[2] (a) H. Schmidbaur, R. Pichl, G. Mu¨eller, Angew. Chem. 98
(1986) 572. (b) W. Scharf, D. Neugebauer, U. Schubert, H.
Schmidbaur, Angew. Chem. 90 (1978) 628. (c) G. Erker, P.
Czisch, R. Benn, A. Rufinska, R.J. Mynott, Organomet. Chem.
328 (1987) 101. (d) G. Erker, P. Czisch, R. Mynott, Y.H Tsey,
C. Kruger, Organometallics 4 (1985) 1310. (e) G. Erker, K.
Ergel, U. Korek, P. Czisch, H. Berke, P. Caubere, R. Vander-
esse, Organometallics 4 (1985) 1531. (f) K.I. Gell, J. Schwartz,
Inorg. Chem. 19 (1980) 3207. (g) G. Erker, P. Czisch, R.
Mynott, J. Organomet. Chem. 334 (1987) 91. (h) G. Erker, P.
Czisch, C. Kruger, J.M. Wallis, Organometallics 4 (1985) 2059.
(i) S. Schmidt, J. Sundermeyer, F. Moller, J. Organomet. Chem.
475 (1994) 157.
[8] F.A. Cotton, L.R. Falvello, R.C. Najjar, Inorg. Chem. 22 (1983)
375.
[9] J.L. Templeton, Adv. Organomet. Chem. 29 (1989) 1.
[10] J. Ferna´ndez-Baeza, F. Jalo´n, A. Otero, M.E. Rodrigo-Blanco,
J. Chem. Soc. Dalton Trans. (1995) 1015.
[11] K. Nakamoto (Eds.), Infrared and Raman Spectra of Inorganic
and Coordination Compounds, Wiley-VCH, New York, 1997.
[12] (a) A.Davidson, J. Ellis, J. Organomet. Chem. 36 (1972) 113. (b)
I. Pforr, F. Na¨umann, D. Rehder, J. Organomet. Chem. 258
(1983) 189. (c) M. Fajardo, P. Go´mez-Sal, P. Royo, S. Mart´ınez-
Carrera, S. Garc´ıa-Blanco, J. Organomet. Chem. 312 (1986) C45.
(d) A. Antin˜olo, F.A. Jalo´n, A. Otero, M. Fajardo, B. Chaudret,
F. Lahoz, J.A. Lo´pez, J. Chem. Soc. Dalton. Trans. (1991) 1861.
(e) A. Antin˜olo, F. Carrillo, B. Chaudret, et al., Inorg. Chem. 33
(1994) 5163. (f) A. Antin˜olo, F. Carrillo, B. Chaudret, et al.,
Organometallics 14 (1995) 1297. (g) A. Antin˜olo, F. Carrillo-
Hermosilla, B. Chaudret et al., Inorg. Chem. 356 (1996) 7873.
[13] R. Hoffmann, Angew. Chem. Int. Ed. Engl. 21 (1982) 711.
[14] A.N. Mueting, W. Bos, B.D. Alexander, et al., New J. Chem. 12
(1988) 506.
[3] J.A. Albanese, D.A. Staley, A.L. Rheingold, J.L. Burmeister,
Inorg. Chem. 29 (1990) 2209.
[4] (a) H. Nishiyama, K. Itoh, Y. Ishii, J. Organomet. Chem. 87
(1975) 129. (b) E.T. Weleski, J.L. Silver, M.D. Jansson, J.L.
Burmeister, J. Organomet. Chem. 102 (1975) 365. (c) P. Bravo,
G. Fronza, C. Ticozzi, J. Organomet. Chem. 111 (1976) 361. (d)
H. Koezuka, G. Matsubayashi, T. Tanaka, Inorg. Chem. 15
(1976) 417. (e) G. Fronza, P. Bravo, C. Ticozzi, J. Organomet.
Chem. 157 (1978) 299. (f) M. Onishi, Y. Ohama, K. Hiraki, H.
Shintani, Polyhedron 1 (1982) 539. (g) G. Facchin, R. Bertani,
[15] E.J. Roskamp, S.F. Pedersen, J. Am. Chem. Soc. 109 (1987)
6551.
[16] S.A.R. Knox, F.G.A. Stone, J. Chem. Soc. A. (1969) 2559.
.