Cationic molybdenum complexes with P-coordinated (diphenylphosphino)alkynes

Article abstract of DOI:10.1016/S0022-328X(00)00256-4

New cationic P-coordinated (diphenylphosphino)alkyne complexes with molybdenum [(Mp)Ph₂PC≡CR][BF₄] {R = H, Me, ^tBu, Ph, Tol; Mp = (C₅H₅)Mo(CO)₃} have been prepared from reaction between a (diphenylphosphino)alkyne Ph₂PC≡CR and the dinuclear complex [(C₅H₅)Mo(CO)₃]₂, with Ag(I) as oxidant. The bis(diphenyphosphosphino)acetylene Ph₂PC≡CPPh₂ led to the following homo- and heteronuclear metal complexes by the same method: [(Mp)Ph₂PC≡CPPh₂][BF₄], [(Mp)Ph₂PC≡ CPPh₂(Mp)][BF₄]₂ and [(Mp)Ph₂PC≡CPPh₂(Fp)][BF₄]₂ (Fp = (C₅H₅)Fe(CO)₂}. The reaction of the P-coordinated molybdenum complexes [(Mp)Ph₂PC≡CR][BF₄] with dicobalt octacarbonyl at room temperature afforded the cationic heterometallic complexes [(Mp)Ph₂PC₂R{Co₂(CO)₆}][BF ₄]. All complexes were characterised by microanalysis and IR, ¹H-, ¹³C- and ³¹P-NMR spectroscopy.

Full text of DOI:10.1016/S0022-328X(00)00256-4

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 604 (2000) 234–240
Cationic molybdenum complexes with P-coordinated
(diphenylphosphino)alkynes
Elmostafa Louattani, Joan Suades *
Departament de Qu´ımica, Edifici C, Uni6ersitat Auto`noma de Barcelona, 08193 Bellaterra, Spain
Received 18 February 2000; accepted 20 April 2000
Abstract
t
New cationic P-coordinated (diphenylphosphino)alkyne complexes with molybdenum [(Mp)Ph2PCꢀCR][BF4] {R=H, Me, Bu,
Ph, Tol; Mp=(C5H5)Mo(CO)3} have been prepared from reaction between a (diphenylphosphino)alkyne Ph2PCꢀCR and the
dinuclear complex [(C5H5)Mo(CO)3]2, with Ag(I) as oxidant. The bis(diphenyphosphosphino)acetylene Ph2PCꢀCPPh2 led to the
following homo- and heteronuclear metal complexes by the same method: [(Mp)Ph2PCꢀCPPh2][BF4], [(Mp)Ph2PCꢀ
CPPh2(Mp)][BF4]2 and [(Mp)Ph2PCꢀCPPh2(Fp)][BF4]2 {Fp=(C5H5)Fe(CO)2}. The reaction of the P-coordinated molybdenum
complexes [(Mp)Ph2PCꢀCR][BF4] with dicobalt octacarbonyl at room temperature afforded the cationic heterometallic complexes
[(Mp)Ph2PC2R{Co2(CO)6}][BF4]. All complexes were characterised by microanalysis and IR, 1H-, 13C- and 31P-NMR spec-
troscopy. © 2000 Published by Elsevier Science S.A. All rights reserved.
Keywords: Phosphinoalkyne; Carbonyl; Cyclopentadienyl; Molybdenum; Cobalt; Iron
Here we describe the synthesis of a new family of
1. Introduction
cationic molybdenum complexes with diphenylphosphi-
noalkynes
[(Mp)Ph2PCꢀCR]+
{Mp=(C5H5)Mo-
The acetylenic phosphines Ph2PCꢀCR have been ex-
tensively studied as ligands in transition metal chem-
istry. The phosphine and the alkyne functions are
usually involved in reactions with polynuclear metal
complexes [1], but P-coordinated transition metal com-
plexes with the uncoordinated alkyne have also been
reported [2]. In previous papers, we have described the
synthesis of anionic [PPh4][Fe3(CO)9(m3-CCH3)-
(Ph2PCꢀCR)] [3], cationic [(Fp)Ph2PCꢀCR][BF4] {Fp=
(C5H5)Fe(CO)2} [4] and zwitterionic P-coordinated iron
complexes [5]. The study of the uncoordinated alkyne
in the cationic complexes [(Fp)Ph2PCꢀCR][BF4] indi-
cates that the cationic charge located on the phospho-
(CO)3}. The isolobal relation between the fragments
{Mp} and {Fp} suggests the viability of these molybde-
num compounds. We aim to compare alkyne polariza-
tion in the new molybdenum complexes with previous
results on the isolobal iron fragment (Scheme 1). If
similar results were obtained, they would provide addi-
tional evidence of the isolobal relationship between
these iron and molybdenum fragments.
Moreover, the molybdenum complexes [(Mp)Ph2-
PCꢀCR]+ may be used as starting materials for the
synthesis of mixed cobalt–molybdenum and iron–
molybdenum complexes. Indeed, on the basis of the
reported synthesis of iron–cobalt complexes [(Fp)Ph2-
PC2R{Co2(CO)6}]+ [6], the preparation of cobalt–
molybdenum compounds seems feasible via the reaction
between the uncoordinated alkyne and dicobalt oc-
tacarbonyl. Similarly, the synthesis of the iron–molyb-
denum complex [(Fp)Ph2PCꢀCPPh2(Mp)]2+ seems
viable starting from the iron complex [(Fp)Ph2PCꢀ
CPPh2]+ [5].
rus atom induces
polarization in the alkyne function (Scheme 1) [4].
a significant CC triple bond
* Corresponding author. Fax: +34-93-5813101.
0022-328X/00/$ - see front matter © 2000 Published by Elsevier Science S.A. All rights reserved.
PII: S0022-328X(00)00256-4

E. Louattani, J. Suades / Journal of Organometallic Chemistry 604 (2000) 234–240
235
1
2. Results and discussion
h5-cyclopentadienyl ligand are observed in the H- and
13C-NMR spectra, whereas the characteristic bands of
the three CO ligands bonded to molybdenum are recog-
nised in the 13C-NMR spectra at 225–227 ppm [8,9].
Indeed, the 31P-NMR spectra of 1–6 show signals at
21–24 ppm, which corroborates the P-coordination of
the (diphenylphospino)alkyne to the molybdenum atom
[10]. Finally, a weak IR band near 2200 cm−1 assigned
to w(CꢀC) of the free triple bond [11] together with the
13C-NMR signals of the acetylenic carbon atoms are
consistent with the presence of an uncoordinated
alkyne. All these data are compatible with the structure
proposed for complexes 1–5 in Scheme 2.
2.1. [(Mp)Ph2PCꢀCR][BF4] (1–5)
A series of molybdenum cationic P-coordinated
(diphenylphosphino)alkyne
complexes
[(Mp)Ph2-
PCꢀCR]+ {R=H (1), CH3 (2), Bu (3), Ph (4), Tol (5)}
were synthesised by oxidation of [(C5H5)Mo(CO)3]2
with AgBF4 in the presence of (diphenylphos-
phino)alkyne (Scheme 2).
t
The products were isolated as yellow micro-crys-
talline solids and characterised by the usual analytical
and spectroscopic techniques. The IR spectra of com-
plexes 1–5 showed a set of three bands in the 2100–
1950 cm−1 region, assigned to the terminal w(CO)
bands of the fragment {CpMo(CO)3}. Similar values
have been reported for the cationic complexes
The chemical shift difference (lC2−lC1) between
the acetylenic carbon atoms for different compounds
has been related to a polarization of the triple bond
[4,12]. Analogously, the sum (lC2+lC1) has been
associated with the charge changes [4,12]. Hence, Table
1 shows these values for iron and molybdenum P-coor-
[(Mp)PR3]+ [7]. This result is consistent with the H-
1
and 13C-NMR spectra: the signals corresponding to an
Scheme 1.
Scheme 2.
Table 1
13C Chemical shifts (l, ppm) for the acetylenic carbons in cationic complexes [(X)Ph2PCꢀCR]+ and free phosphinoalkynes Ph2PCꢀCR
R
X
l(C1)
l(C2)
l(C1)+l(C2)
l(C2)−l(C1)
H
H
H
Me
Me
Me
tBu
tBu
tBu
Ph
Ph
Ph
Tol
Tol
Tol
92.0
76.1
78.5
75.4
70.9
74.0
75.2
70.9
71.2
86.5
80.3
80.6
85.3
80.0
79.8
98.8
107.0
109.1
107.2
117.9
117.3
119.5
127.9
128.2
109.4
115.7
116.1
108.9
116.5
116.7
190.8
183.1
187.6
182.6
188.8
191.3
194.7
198.8
199.4
195.9
196.0
196.7
194.2
196.5
196.5
6.8
30.9
30.6
31.8
47.0
43.3
44.3
57.0
57.0
22.9
35.4
35.5
23.6
36.5
36.9
CpFe(CO)2
CpMo(CO)3
CpFe(CO)2
CpMo(CO)3
CpFe(CO)2
CpMo(CO)3
CpFe(CO)2
CpMo(CO)3
CpFe(CO)2
CpMo(CO)3

236
E. Louattani, J. Suades / Journal of Organometallic Chemistry 604 (2000) 234–240
Scheme 3.
2.2. [(Mp)Ph2PCꢀCPPh2][BF4] (6) and
[(Mp)Ph2PCꢀCPPh2(Mp)][BF4]2 (7)
dinated phoshinoalkyne complexes. As mentioned
above, the comparison between the alkyne polarisation
of these two families of complexes may provide infor-
mation about the electronic behaviour of the isolobal
fragments {Mp} and {Fp}. The results obtained for the
molybdenum complexes (Table 1) show similar trends
to those previously observed with the iron complexes,
which can be summarized as follows: (1) there is a small
influence of P-coordination on the alkyne charge
(lC2+lC1); (2) there is an important effect on the
polarization of the CꢀC triple bond. Finally, the most
remarkable feature in Table 1 is the strong similarity
between the values shown by the iron and molybdenum
complexes prepared with the same (diphenylphos-
phino)alkyne. This may be attributable to a similar
CꢀC polarization in the homologous iron and molybde-
num complexes, which denotes a similar electronic infl-
uence of the iron and molybdenum fragments on the
alkyne function.
As shown in Scheme 3, complexes 6 and 7 were
prepared by oxidation of the dinuclear complex
[(C5H5)Mo(CO)3]2 with AgBF4 in the presence of the
diphosphine. By using the appropriate ratio of reagents,
complexes 6 and 7 were selectively isolated and charac-
terised by the usual spectroscopic and analytical meth-
ods. The different symmetry in 6 and 7 is revealed by
their IR and 31P-NMR spectra. Thus, the IR spectrum
of 6 shows a band at 2122 cm−1 assigned to w(CꢀC),
which is absent in 7; this is consistent with the struc-
tures shown in Scheme 3. The 31P-NMR spectrum of 7
shows only one signal at 25.3 ppm assigned to the
phosphorus atom coordinated to molybdenum. In con-
trast, the spectrum of 6 exhibits two signals: one peak
at 23.4 ppm, assigned to the phosphorus atom bonded
to molybdenum, and another at −20.2 ppm, which is
characteristic of an uncoordinated phosphorus atom.

E. Louattani, J. Suades / Journal of Organometallic Chemistry 604 (2000) 234–240
237
Consequently, the simple synthetic method previously
2.4. [(Mp)Ph2PC2R{Co2(CO)6}][BF4] (9–11)
{R=CH3 (9), Ph (10), Tol (11)}
used for the synthesis of the diphenylphosphine iron
complexes [(Fp)Ph2PCꢀCPPh2][BF4] and [(Fp)Ph2-
PCꢀCPPh2(Fp)][BF4]2 [5] may be extended to the
synthesis of the homologous molybdenum complexes
(Scheme 3).
The reaction between the cationic complexes
[(Mp)Ph2PCꢀCR]+ and [Co2(CO)8] at room tempera-
ture in dichloromethane afforded the complexes 9–11
(Scheme 4), which were isolated as brown microcrys-
talline solids and characterised by the usual analytical
and spectroscopic techniques. The IR spectrum of 9–11
indicates alkyne coordination since it shows a set of
bands at 2100–2000 cm−1 with marked similarity to
the w(CO) absorption of the Co2(CO)6 fragment [6,15],
overlapping the w(CO) bands of the [CpMo(CO)3]+
fragment [7]. The absence of the w(CꢀC) band of the
uncoordinated alkyne also suggests the coordination of
the CꢀC bond. The 31P-NMR spectrum reveals the
alkyne coordination, since phosphorus resonances in
complexes 9–11 are shifted nearly 25 ppm downfield
with respect to those of the corresponding alkyne com-
plex [(Mp)Ph2PCꢀCR]+. This displacement is ascribed
to the loss of the electron ring current associated with
the p(CꢀC) bond [16] as a result of the alkyne coordina-
tion to the cobalt fragment. The carbonyl groups
bonded to cobalt and molybdenum atoms are observed
as separate signals in the 13C-NMR spectra for com-
plexes 9–11. The carbonyl resonances of MoꢁCO
groups appear at about the same position as in the
corresponding alkyne complexes [(Mp)Ph2PCꢀCR)]+
2.3. [(Mp)Ph2PCꢀCPPh2(Fp)][BF4]2 (8)
The successful synthesis of mono- and bimetallic iron
and molybdenum complexes with Ph2PCꢀCPPh2 in-
duced us to attempt the preparation of a heterometallic
iron–molybdenum complex. As shown in Scheme 3,
two synthetic pathways are possible, depending on the
starting material: [(Mp)Ph2PCꢀCPPh2][BF4] or [(Fp)-
Ph2PCꢀCPPh2][BF4]. Both methods were performed
and the resulting compounds were isolated as yellow
microcrystalline solids with comparable yields. Analyti-
cal and spectroscopic methods showed that complexes
obtained by the two pathways are identical, and their
formulations agree with that of the title complex 8.
Thus, the IR spectrum shows a weak band at 2122
cm−1 which, in agreement with the proposed het-
erometallic structure (Scheme 3), is characteristic of an
asymmetric arrangement around the CꢀC bond. Fur-
thermore, the w(CO) region displays a set of bands that
are practically superpositions of the characteristic
bands of the cationic {CpMo(CO)3} [7] and {CpFe-
(CO)2} [4] fragments. The asymmetric coordination of
Ph2PCꢀCPPh2 to the two different metallic fragments is
corroborated by the 31P-NMR spectrum, which shows
two bands at 24.7 and 46.7 ppm: these are, respectively,
assigned to the phosphorus atoms bonded to the
2
and only the JPꢁC values for the MoꢁCO(cis) are
slightly lower. In addition, the carbonyl resonances of
the CoꢁCO groups are observed as broad signals at
nearly 198 ppm [17], in a position very similar to that
previously reported for the iron–cobalt complexes
1
[(Fp)Ph2PC2R{Co2(CO)6}]+
[6].
Unfortunately,
molybdenum and to the iron fragment [13]. The H-
and 13C-NMR spectrum shows the signals of the two
different cyclopentadienyl groups bonded to iron and
molybdenum atoms, and different carbonyl groups are
also observed in the 13C-NMR spectrum.
acetylenic carbon resonances were observed only for
complex 10, as two doublets at 84.6 ppm (1JPC=10.2
Hz, PCꢀ) and 108.9 ppm (2JPC=7.7 Hz, ꢀCPh). These
chemical shifts are also very similar to those previously
reported [6] for the homologous iron complex
[(Fp)Ph2PC2Ph{Co2(CO)6}]+ (84.7 and 107.7 ppm), so
the electronic distribution of the acetylenic group
Finally, the overall synthetic results obtained with
bis(diphenylphosphino)acetylene (Scheme 3) confirm its
ability to form mono- or bimetallic cationic metal
complexes with iron or molybdenum fragments. Since
P-coordinated complexes of this ligand with different
metals have been reported [14], the simple synthesis
displayed in Scheme 3 can be used to prepare new
heterometallic complexes.
1
should be similar in both complexes. Finally, the H-
and 13C-NMR spectra show the resonances of Ph, Cp
and R groups, with no exceptional chemical shifts.
The reaction between complex 3 and [Co2(CO)8] did
not lead to the corresponding cobalt complex, and the
Scheme 4.

238
E. Louattani, J. Suades / Journal of Organometallic Chemistry 604 (2000) 234–240
reagents were recovered. This different behaviour is
reported elsewhere [6], and can be assigned to the steric
hindrance of the bulky tert-butyl group. In contrast,
complex 1 showed similar behaviour to 2, 4 and 5, but
the corresponding cobalt complex could not be isolated
in an acceptable grade of purity.
2.41 (d, 4JPC=4.0 Hz, CH3), 6.11 (s, Cp). 31P{1H}-
NMR (acetone-d6): 22.4. 13C{1H}-NMR (acetone-d6;
3
except phenyl resonances): 5.2 (d, JPC=3 Hz, CH3),
74.0 (d, 1JPC=66.7 Hz, ꢀCP), 97.2 (Cp), 117.3 (d,
2JPC=15.2 Hz, ꢀCMe), 225.4 (d, 2JPC=30.4 Hz, COcis)
226.8 (s, COtrans).
Yield of 3: 70%. Anal. Calc. for C26H24BF4MoO3P:
C, 52.20; H, 4.04. Found: C, 51.44; H, 4.10%. IR
(CH2Cl2, cm−1): 2210(w), 2170(m) (wCꢀC); 2063(s),
2004(m), 1975(s) (wCO). 1H-NMR (acetone-d6; except
3. Experimental
t
3.1. General
phenyl resonances): 1.46 (s, Bu), 6.10 (s, Cp). 31P{1H}-
NMR (acetone-d6): 21.2. 13C{1H}-NMR (acetone-d6;
All reactions were performed under nitrogen by stan-
dard Schlenk tube techniques. Infrared spectra were
recorded with a Perkin–Elmer 1710 FT spectrometer
using dichloromethane solutions or KBr pellets. The
NMR spectra were recorded by the Servei de Resso-
nancia Magne`tica Nuclear de la Universitat Auto`noma
de Barcelona on a Bruker AM400 instrument. All
chemical shift values are given in ppm and are refer-
enced with respect to residual protons in the solvents
except phenyl resonances): 24.3 (s, CH3), 71.2 (d,
2
1JPC=109.1 Hz, ꢀCP), 97.3 (Cp), 128.2 (d, JPC=15.3
2
Hz, ꢀC-tBu), 225.8 (d, JPC=27.8 Hz, COcis) 226.6 (s,
COtrans).
Yield of 4: 75%. Anal. Calc. for C28H20BF4MoO3P:
C, 54.40; H, 3.26. Found: C, 54.41; H, 3.40%. IR
(CH2Cl2, cm−1): 2173(m) (wCꢀC); 2063(s), 2005(m),
1976(s) (wCO). 1H-NMR (acetone-d6; except phenyl reso-
nances): 6.19 (s, Cp). 31P{1H}-NMR (acetone-d6): 22.8.
13C{1H}-NMR (acetone-d6; except phenyl resonances):
80.6 (d, 1JPC=105.8 Hz, ꢀCP), 97.5 (Cp), 116.1 (d,
1
for H spectra, to solvent signals for 13C spectra and to
phosphoric acid for 31P spectra.
Compounds Ph2PCꢀCR (R=H, CH3, Bu, Ph, Tol,
t
2
2JPC=16.6 Hz, ꢀCPh), 225.5 (d, JPC=28.2 Hz, COcis)
PPh2) were prepared by published procedures
[3,14a,18]. Microanalyses were performed in Servei
d’Ana`lisi Qu´ımica de la Universitat Auto`noma de
Barcelona.
226.3 (s, COtrans).
Yield of 5: 64%. Anal. Calc. for C29H22BF4MoO3P:
C, 55.10; H, 3.51. Found: C, 55.00; H, 3.67%. IR
(CH2Cl2, cm−1): 2172(m) (wCꢀC); 2063(s), 2004(m),
1
1973(s) (CO). H-NMR (acetone-d6; except phenyl reso-
t
3.2. Synthesis of (1–5) {R=H (1), CH3 (2), Bu (3),
nances): 2.44 (s, CH3), 6.17 (s, Cp). 31P{1H}-NMR
Ph (4), Tol (5)}
(acetone-d6): 22.8. 13C{1H}-NMR (acetone-d6; except
1
phenyl resonances): 21.4 (s, CH3), 79.8 (d, JPC=110.0
2
In a typical procedure, a solution of Ph2PCꢀCR (2.1
mmol) in dicloromethane (5 ml) was added to a solu-
tion of [CpMo(CO)3]2 (0.500 g, 1.0 mmol) in
dichloromethane (15 ml). Solid AgBF4 (0.400 g, 2.0
mmol) was added and the reaction mixture was stirred
at room temperature (r.t.) for 1 week. Next, solid silver
was filtered off and the solution was evaporated to
dryness. The residue was recrystallized from 2:1
CH2Cl2–diethyl ether at −20°C. The yellow crystals
that separated were collected, washed in diethyl ether
and dried in vacuo.
Hz, ꢀCP), 97.3 (Cp), 116.7 (d, JPC=18.6 Hz, ꢀCPh),
2
225.4 (d, JPC=30.0 Hz, COcis), 226.3 (s, COtrans).
3.3. Synthesis of 6
A solution of Ph2PCꢀCPPh2 (0.480 g, 1.2 mmol) in
dicloromethane (5 ml) was added to a solution of
[CpMo(CO)3]2 (0.300 g, 0.6 mmol) in dichloromethane
(15 ml). Solid AgBF4 (0.240 g, 1.2 mmol) was added
and the reaction mixture was stirred at r.t. for 1 week.
Next, solid silver was filtered off and the solution was
evaporated to dryness. The residue was recrystallized
from 2:1 CH2Cl2–diethyl ether at −20°C. The yellow
crystals that separated were collected, washed in diethyl
ether and dried in vacuo.
Yield of 1: 62%. Anal. Calc. for C22H16BF4MoO3P:
C, 48.75; H, 2.98. Found: C, 48.30; H, 2.90%. IR
1
(CH2Cl2, cm−1): 2065(s), 2005(m), 1976(s) (wCO). H-
NMR (acetone-d6; except phenyl resonances): 5.32 (d,
3JPH=12 Hz, HCꢀ), 6.15 (s, Cp). 31P{1H}-NMR (ace-
tone-d6): 23.3. 13C{1H}-NMR (acetone-d6; except
Yield of 6: 63%. Anal. Calc. for C34H25BF4MoO3P2:
C, 56.23; H, 3.47. Found: C, 56.42; H, 3.36%. IR
(CH2Cl2, cm−1): 2122(w) (wCꢀC); 2066(s), 2007(m),
1977(s) (wCO). 1H-NMR (acetone-d6; except phenyl
resonances): 6.19 (s, Cp). 31P{1H}-NMR (acetone-d6):
−20.2 (b, PPh2), 23.4 (b, MoꢁPPh2). 13C{1H}-NMR
(acetone-d6; except phenyl resonances): 96.5 (s, Cp),
1
phenyl resonances): 78.5 (d, JPC=62.5 Hz, ꢀCP), 97.5
2
2
(Cp), 109.1 (d, JPC=12.3 Hz, ꢀCH), 225.0 (d, JPC
=
25.2 Hz, COcis) 226.0 (s, COtrans).
Yield of 2: 68%. Anal. Calc. for C23H18BF4MoO3P:
C, 49.68; H, 3.26. Found: 49.34; H, 3.42%. IR (CH2Cl2,
cm−1): 2202(m) (wCꢀC); 2063(s), 2003(m), 1975(s)
(wCO).1H-NMR (acetone-d6; except phenyl resonances):
2
224.6 (d, JPC=25.2 Hz, COcis), 225.1 (s, COtrans) (the
signals for acetylenic carbons could not be identified).

E. Louattani, J. Suades / Journal of Organometallic Chemistry 604 (2000) 234–240
239
2
3.4. Synthesis of 7
Hz, FeCO), 224.1 (d, JPC=26.8 Hz, MoCOcis), 225.3
(s, MoCOtrans) (the signals for acetylenic carbons could
not be identified).
A solution of Ph2PCꢀCPPh2 (0.240 g, 0.6 mmol) in
dicloromethane (5 ml) was added to a solution of
[CpMo(CO)3]2 (0.300 g, 0.6 mmol) in dichloromethane
(15 ml). Solid AgBF4 (0.24 g, 1.2 mmol) was added and
the reaction mixture was stirred at r.t. for 1 week. Next,
solid silver was filtered off and the solution was evapo-
rated to dryness. The residue was recrystallized from
2:1 CH3CN–diethyl ether at −20°C. The yellow crys-
tals that separated were collected, washed in diethyl
ether and dried in vacuo.
3.6. Synthesis of 9–11 {R=CH3 (9), Ph (10), Tol
(11)}
In a typical procedure, a solution of [Co2(CO)8]
(0.110 g, 0.32 mmol) in dicloromethane (15 ml) was
added with stirring to [(Mp)Ph2PCꢀCR][BF4] (0.32
mmol) in dichloromethane (15 ml). The solution was
stirred at r.t. for 20 h, filtered, and evaporated to
dryness. The residue was recrystallized from 1:1
CH2Cl2–diethyl ether at −20°C. The brown crystals
that separated were collected, washed in diethyl ether
and dried in vacuo.
Yield of 7: 65%. Anal. Calc. for C42H30B2F8-
Mo2O6P2: C, 47.67; H, 2.86. Found: C, 47.02; H,
2.97%. IR (KBr, cm−1): 2064(s), 2007(sh), 1970(s)
(wCO). 1H-NMR (CD3CN; except phenyl resonances):
6.04 (s, Cp). 31P{1H}-NMR (CD3CN): 25.3. 13C{1H}-
NMR (CD3CN; except phenyl resonances): 96.8 (s,
Yield of 9: 75%. Anal. Calc. for C29H18BCo2F4-
MoO9P: C, 41.37; H, 2.15. Found: C, 41.37; H, 2.34%.
IR (CH2Cl2, cm−1): 2101(m), 2067(s), 2045(s), 2010(m)
1
2
Cp), 106.2 (dd, JPC=72.5, JPC=3.8 Hz, CP), 223.8
1
2
1963(m) (wCO). H-NMR (acetone-d6; except phenyl res-
(d, JPC=26.8 Hz, COcis), 224.2 (s, COtrans).
onances): 3.28 (s, CH3), 5.95 (s, Cp). 31P{1H}-NMR
(acetone-d6): 47.7. 13C{1H}-NMR (acetone-d6; except
phenyl resonances): 23.3 (s, CH3), 96.7 (s, Cp), 198.1 (b,
CoCO), 226.6 (s, COtrans) 227.9 (d, 2JPC=25.0 Hz,
COcis) (the signals for acetylenic carbons could not be
identified).
3.5. Synthesis of 8
3.5.1. Method 1 (starting from complex 6)
Solid complex 6 (0.350 g, 0.48 mmol) was added to a
solution of [CpFe(CO)2]2 (0.086 g, 0.26 mmol) in
dichloromethane (15 ml). The resulting solution was
stirred for 5 min at r.t. and a solution of [FeCp2][BF4]
(0.130 g, 0.48 mmol) in dichloromethane (5 ml) was
added. The solution was stirred at r.t. for 3 h, FeCp2
filtered off, and evaporated to dryness. The residue
was recrystallized from 2:1 CH2Cl2–diethyl ether at
−20°C. The yellow crystals that separated were col-
lected, washed in diethyl ether and dried in vacuo.
Yield 65%.
Yield of 10: 75%. Anal. Calc. for C34H20BCo2F4-
MoO9P: C, 45.17; H, 2.23. Found: C, 44.79; H, 2.37%.
IR (CH2Cl2, cm−1): 2103(m), 2070(s), 2050(s), 2020(m)
1
1969(m) (wCO). H-NMR (acetone-d6; except phenyl res-
onances): 5.87 (s, Cp). 31P{1H}-NMR (acetone-d6):
47.5. 13C{1H}-NMR (acetone-d6; except phenyl reso-
1
nances): 84.6 (d, JPC=10.2 Hz, CPPh2), 97.4 (s, Cp),
2
108.9 (d, JPC=7.7 Hz, CPh), 198.6 (b, CoCO), 225.4
2
(s, COtrans), 227.9 (d, JPC=25.7 Hz, COcis).
Yield of 11: 72%. Anal. Calc. for C35H22BCo2F4-
MoO9P: C, 45.79; H, 2.42. Found: C, 45.47; H, 2.44%.
IR (CH2Cl2, cm−1): 2098(m), 2065(s), 2036(s), 2022(m)
3.5.2. Method 2 (starting from
[(Fp)Ph2PCꢀCPPh2][BF4])
1
1975(m) (wCO). H-NMR (acetone-d6; except phenyl res-
Solid [CpMo(CO)3]2 (0.350 g, 0.7 mmol) and solid
AgBF4 (0.270 g, 1.4 mmol) were added to a solution of
[(Fp)Ph2PCꢀCPPh2][BF4] (0.900 g, 1.4 mmol) in
dichloromethane (15 ml) and the reaction mixture was
stirred at r.t. for 1 week. Next, solid silver was filtered
off and the solution was evaporated to dryness. The
residue was recrystallized from 2:1 CH2Cl2–diethyl
ether at −20°C. The yellow crystals that separated
were collected, washed in diethyl ether and dried in
vacuo. Yield 57%.
onances): 2.40 (s, CH3), 5.89 (s, Cp). 31P{1H}-NMR
(acetone-d6): 47.5. 13C{1H}-NMR (acetone-d6; except
phenyl resonances): 22.6 (s, CH3), 96.7 (s, Cp), 198.0 (b,
CoCO), 226.2 (s, COtrans), 227.2 (d, 2JPC=23.2 Hz,
Cocis) (the signals for acetylenic carbons could not be
identified).
Acknowledgements
Anal. Calc. for C41H30B2F8FeMoO5P2: C, 49.74; H,
3.05. Found: C, 49.29; H, 3.20%. IR (CH2Cl2, cm−1):
2065(s), 2022(s), 1978(s) (wCO). IR (KBr, cm−1):
2122(w) (wCꢀC). 1H-NMR (acetone-d6; except phenyl
resonances): 5.76 (s, CpFe), 6.11 (s, CpMo). 31P{1H}-
NMR (acetone-d6): 24.7(s, PMo), 46.7(s, PFe).
13C{1H}-NMR (acetone-d6; except phenyl resonances):
We thank the DGICYT (Programa de Promocio´n
General del Conocimiento) for financial support.
References
[1] Some examples: (a) A.J. Carty, Adv. Chem. Ser. 196 (1981) 163.
(b) M.I. Bruce, M.L. Williams, J.M. Patrick, A.H. White. J.
2
89.9 (s, CpFe), 97.3 (s, CpMo), 208.6 (d, JPC=22.5

240
E. Louattani, J. Suades / Journal of Organometallic Chemistry 604 (2000) 234–240
Chem. Soc. Dalton Trans. (1985) 1229. (c) D. Nucciarone, S.A.
[8] The CO ligands placed cis to phosphorus are observed as a
doublet (2JPC 25–30 Hz) and the CO trans as a singlet, slightly
downfield shifted [9].
[9] (a) A. Asdar, M. Tudoret, C. Lapinte, J. Organomet. Chem. 349
(1988) 353. (b) N. Kuhn, H. Shumann, E. Zauder, J. Organomet.
Chem. 354 (1988) 161.
[10] These values are similar to the 26.4 ppm reported for the
complex [(C5Me5)Mo(CO)3PPh2Me]+ [9a].
[11] The w(CꢀCH) band could not be detected in complex 1 and two
bands were observed for the tert-butyl complex 3. A similar
behaviour has been previously reported for the iron complexes
[(Fp)Ph2PCꢀCR]+ [4].
[12] (a) D. Rosenberg, W. Drenth, Tetrahedron 27 (1971) 3893. (b)
G.N. Mott, A.J. Carty, Inorg. Chem. 22 (1983), 2726.
[13] The monometalic complexes [(Mp)Ph2PCꢀCPPh2][BF4] (6) and
[(Fp)Ph2PCꢀCPPh2][BF4] (5) show one signal in the 31P-NMR
spectrum assigned to the phosphorus atom bonded to the metal
at 23.4 and 46.5 ppm, respectively.
[14] (a) R.B. King, A. Efraty, Inorg. Chem. 8 (1969) 2374. (b) A.J.
Carty, A. Efraty, T.W. Ng, T. Birchall, Inorg. Chem. 9 (1970)
1263. (c) R.C. Taylor, R.L. Keiter, L.W. Cary, Inorg. Chem. 13
(1974) 1928. (d) O. Orama, J. Organomet. Chem. 314 (1986) 273.
(e) E. Sappa, J. Organomet. Chem. 352 (1988) 327. (f) A.J.
Amoroso, B.F.G. Johnson, J. Lewis, A.D. Massey, P.R.
Raithby, W.T. Wong, J. Organomet. Chem. 440 (1992) 219.
[15] T.M. Wido, G.H. Young, A. Wojcicki, M. Calligaris, G. Nardin,
Organometallics 7 (1988) 452.
MacLaughlin, N.J. Taylor, A.J. Carty, Organometallics 7 (1988)
106. (d) E. Sappa, G. Pasquinelli, A. Tiripicchio, M. Tiripicchio-
Camellini, J. Chem. Soc. Dalton Trans. (1989) 601. (e) H. Lang,
L. Zsolnai, J. Organomet. Chem. 369 (1989) 131. (f) D. Montllo´,
J. Suades, M.R. Torres, A. Perales, R. Mathieu, J. Chem. Soc.
Chem. Commun. (1989) 97. (g) P. Blenkiron, G.D. Enright, P.J.
Low, J.F. Corrigan, N.J. Taylor, Y. Chi, J.Y. Saillard, A.J.
Carty, Organometallics 17 (1998) 2447. (h) J.E. Davies, M.J.
Mays, P.R. Raithby, K. Sarveswaran, G.P. Shields, J.
Organomet. Chem. 573 (1999) 180.
[2] Some examples: (a) Y.S. Wong, S. Jacobson, P.C. Chieh, A.J.
Carty, Inorg. Chem. 13 (1974) 284. (b) D.F. Jones, P.H.
Dixneuf, T.G. Southern, J. Marouille, D. Grandjean, P. Guenot,
Inorg. Chem. 20 (1981) 3247. (c) E. Sappa, G. Predieri, A.
Tiripicchio, M. Tiripicchio Camellini. J. Organomet. Chem. 297
(1985) 103. (d) W. Imhof, B. Eber, G. Huttner, C. Emmerich, J.
Organomet. Chem. 447 (1993) 21. (e) I. Moldes, J. Ros. Inorg.
Chim. Acta 232 (1995) 75. (f) I. Ara, L.R. Falvello, S. Fernan-
dez, J. Fornies, E. Lalinde, A. Martin, M.T. Moreno,
Organometallics 16 (1997) 5923.
[3] E. Louattani, J. Suades, R. Mathieu, J. Organomet. Chem. 421
(1991) 335.
[4] E. Louattani, A. Lledo´s, J. Suades, A. Alvarez-Larena, J.F.
Piniella, Organometallics 14 (1995) 1053.
[5] E. Louattani, J. Suades, K. Urtiaga, M.I. Arriortua, X. Solans,
Organometallics 15 (1996) 468.
[6] E. Louattani, J. Suades, A. Alvarez-Larena, J.F. Piniella, G.
Germain, J. Organomet. Chem. 506 (1996) 121.
[16] J.G. Verkade, L.D. Quin (Eds.), 31P-NMR Spectroscopy in
Stereochemical Analysis (Methods in Stereochemical Analysis,
8), VCH, Florida, 1987, p. 91.
[17] S. Aime, L. Milone, M. Valle, Inorg. Chim. Acta 18 (1976) 9.
[18] (a) C. Charrier, W. Chodkiewicz, P. Cadiot, Bull. Soc. Chim. Fr.
(1966) 1002. (b) A.J. Carty, N.K. Hota, T.W. Ng, H.A. Patel,
T.J. O’Connor, Can. J. Chem. 49 (1971) 2706.
[7] (a) P.M. Treichel, K.W. Barnett, R.L. Shubkin, J. Organomet.
Chem. 7 (1967) 449. (b) D.H. Gibson, K. Owens, T. Ong, J. Am.
Chem. Soc. 106 (1984) 1125. (c) C.E. Philbin, A.S. Goldman,
D.R. Tyler, Inorg. Chem. 25 (1986) 4434. (d) P. Leoni, E.
Aquilini, M. Pasquali, F. Marchetti, M. Sabat, J. Chem. Soc.
Dalton Trans. (1988) 329.
.