New [Mo(η3-allyl)(CO)2L3]+ complexes with monodentate or tridentate nitrogen-donor ligands

Article abstract of DOI:10.1039/b417332e

Cationic complexes [Mo(η³-allyl)(CO)₂L ₃]⁺ (L₃ = either nitrogen-donor tridentate ligand or three monodentate ligands) were prepared in high yield and under mild conditions using as precursors either the triflato complex [Mo(η ³-allyl)(OTf)(CO)₂(NCMe)₂] or the combination of the chloro complex [Mo(η³-allyl)Cl(CO)₂(NCMe) ₂] and the salt NaBAr′₄ (Ar′ = 3,5-bis(trifluoromethyl)phenyl). The tridentate ligands employed were 2,2′:6′,2′-terpyridine (terpy) and cis,cis-1,3,5- cyclohexanetriamine (CHTA), whereas the monodentate ligands imidazole (im) and 3,5-dimethylpyrazole (dmpz) were chosen. In order to stabilize the labile intermediates, an excess of acetonitrile was used in most of the syntheses. However, the pyrazole complex was prepared through a nitrile-free route to avoid reactions at the coordinated nitrile. The solid state structures of [Mo(η³-methallyl)(CO)₂ (terpy)]OTf (2), [Mo(η³-methallyl)(CO)₂(CHTA)]BAr′₄ (3), [Mo(η³-methallyl)(CO)₂(NCMe)₃] BAr′₄ (4), [Mo(η³-allyl)(CO)₂(im) ₃]OTf (5) and [Mo(η³-allyl)(CO)₂(dmpz) ₃]BAr′₄ (6) were determined by means of single-crystal X-ray diffraction. The Royal Society of Chemistry 2005.

Full text of DOI:10.1039/b417332e

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F U L L P A P E R
New [Mo(g3-allyl)(CO)2L3]+ complexes with monodentate or
tridentate nitrogen-donor ligands
Julio Pe´rez,*a Dolores Morales,a Sonia Nieto,a Luc´ıa Riera,a V´ıctor Rieraa and Daniel Miguelb
a Departamento de Qu´ımica Orga´nica e Inorga´nica-IUQOEM, Facultad de Qu´ımica-CSIC,
Universidad de Oviedo, 33006, Oviedo, Spain. E-mail: japm@fq.uniovi.es;
Fax: 34 98510 3446; Tel: 34 98510 3467
b Departamento de Qu´ımica Inorga´nica, Facultad de Ciencias, Universidad de Valladolid, 47071,
Valladolid, Spain
Received 15th November 2004, Accepted 14th January 2005
First published as an Advance Article on the web 26th January 2005
3
Cationic complexes [Mo(g -allyl)(CO)2L3]+ (L3 = either nitrogen-donor tridentate ligand or three monodentate
ligands) were prepared in high yield and under mild conditions using as precursors either the triflato complex
3
3
[Mo(g -allyl)(OTf)(CO)2(NCMe)2] or the combination of the chloro complex [Mo(g -allyl)Cl(CO)2(NCMe)2] and the
salt NaBArꢀ4 (Arꢀ = 3,5-bis(trifluoromethyl)phenyl). The tridentate ligands employed were 2,2ꢀ:6ꢀ,2ꢀ-terpyridine
(terpy) and cis,cis-1,3,5-cyclohexanetriamine (CHTA), whereas the monodentate ligands imidazole (im) and
3,5-dimethylpyrazole (dmpz) were chosen. In order to stabilize the labile intermediates, an excess of acetonitrile was
used in most of the syntheses. However, the pyrazole complex was prepared through a nitrile-free route to avoid
3
reactions at the coordinated nitrile. The solid state structures of [Mo(g -methallyl)(CO)2(terpy)]OTf (2),
3
3
3
[Mo(g -methallyl)(CO)2(CHTA)]BArꢀ4 (3), [Mo(g -methallyl)(CO)2(NCMe)3]BArꢀ4 (4), [Mo(g -allyl)(CO)2(im)3]OTf
(5) and [Mo(g -allyl)(CO)2(dmpz)3]BArꢀ4 (6) were determined by means of single-crystal X-ray diffraction.
3
Introduction
Results and discussion
3
Pseudooctahedral molybdenum allyldicarbonyl complexes
The addition of AgOTf to [Mo(g -methallyl)Cl(CO)2(NCMe)2]6
(1) in CH2Cl2/MeCN caused an instantaneous change in the
color of the solution (from yellow to orange), a shift to higher
wavenumbers in the m(CO) bands, and the precipitation of AgCl.
A dichloromethane solution of the solid obtained after filtration
and solvent evaporation reacted instantaneously with nitrogen-
donor tridentate ligands (see Scheme 1). We have chosen cis,cis-
1,3,5-cyclohexanetriamine (CHTA)7 and 2,2ꢀ:6ꢀ,2ꢀꢀ-terpyridine
(terpy), two ligands with structures favoring fac and mer
tridentate coordinations respectively for their complexes.
3
[Mo(g -allyl)(CO)2L3] in which some of the L ligands are
nitrogen donors are involved in several stoichiometric1 and
catalytic2 organic transformations, and complexes of this kind
with biologically relevant ligands have been the subject of recent
studies.3 Cationic complexes with L3 = tris(pyrazolyl)alkane
are also among the earlier examples of compounds with
these ligands;4 however, other [Mo(g -allyl)(CO)2L3]+ complexes
3
remain scarce,5 in particular those with monodentate ligands.
Moreover, the synthesis of these compounds often requires long
reaction times, aqueous workup procedures or a large excess of
halide abstracting salts; such as sodium hexafluorophosphate. In
3
The product [Mo(g -methallyl)(CO)2(terpy)]OTf (2) was eas-
ily isolated by crystallization, whereas for the CHTA derivative
it was found that both crystallinity and stability improved after
3
recent work with complexes containing {Mo(g -allyl)(CO)2(N–
N)} (N–N = 2,2ꢀ-bipyridine or 1,10-phenanthroline) fragments,
counteranion exchange using NaBArꢀ4; thus the salt [Mo(g -
3
3
we have found that [Mo(g -allyl)(OTf)(CO)2(N–N)] (OTf =
methallyl)(CO)2(CHTA)]BArꢀ4 (3) was isolated.8
triflate) complexes, or the derivatives obtained by means
of triflate abstraction using the salt NaBArꢀ4 (Arꢀ = 3,5-
bis(trifluoromethyl)phenyl) are good precursors for the high
yield synthesis of cationic compounds under mild conditions.6
Here we report the application of similar strategies to the
Compounds 2 and 3 were obtained in high yield, and
were characterized in solution by means of IR and NMR
spectroscopies, and in the solid state using single-crystal X-
ray diffraction (see Figs. 1 and 2).9 The IR spectra of the
two new compounds consist of two m(CO) bands of similar
intensity, indicating the persistence of the cis-Mo(CO)2 units.
synthesis of different types of [Mo(g -allyl)(CO)2L3]+ complexes.
3
Scheme 1
T h i s j o u r n a l i s
8 8 4
D a l t o n T r a n s . , 2 0 0 5 , 8 8 4 – 8 8 8
T h e R o y a l S o c i e t y o f C h e m i s t r y 2 0 0 5
©

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that of 2 is unprecedented in the chemistry of pseudooctahedral
molybdenum allyldicarbonyl complexes.11
The salt NaBArꢀ4 can be used directly as halide abstractor
thus avoiding the need of employing silver salts. We have found
that the reaction of 1 with NaBArꢀ4 and excess acetonitrile
3
affords [Mo(g -methallyl)(CO)2(NCMe)3]BArꢀ4 (4), which could
be isolated in good yield by filtration followed by crystallization
(Scheme 2).
Scheme 2
3
The cation [Mo(g -C3H5)(CO)2(NCMe)3]+ has been isolated
previously as its hexafluorophosphate salt by Brisdon and
Cartwright as the product of the reaction of the chloro-
bis(nitrile) complex with KPF6 in MeCN.12 These authors
reported a reaction time of 48 hours. Recently, de Azevedo
and coworkers prepared the cationic tris(nitrile) complex in
a shorter reaction time (three hours in refluxing acetonitrile),
employing thallium hexafluorophosphate as halide abstractor.10
In contrast, the reaction of 1, NaBArꢀ4 and MeCN occurs
at the time of mixing the reagents. Single crystals of 4 were
subjected to an X-ray structural determination. The results,
Fig. 1 Thermal ellipsoid plot◦ (30%) of the cation of 2. Selected
˚
bond lengths (A) and angles ( ): Mo(1)–C(2) 1.973(3), Mo(1)–C(1)
1.995(3), Mo(1)–N(2) 2.155(2), Mo(1)–N(1) 2.206(2), Mo(1)–N(3)
2.212(2), Mo(1)–C(4) 2.330(3), Mo(1)–C(3) 2.338(3), Mo(1)–C(5)
2.373(3); C(2)–Mo(1)–C(1) 74.76(11), C(2)–Mo(1)–N(2) 164.25(10),
C(1)–Mo(1)–N(2) 97.73(10), C(2)–Mo(1)–N(1) 92.98(10), C(1)–
Mo(1)–N(1) 90.54(10), N(2)–Mo(1)–N(1) 73.01(8), C(2)–Mo(1)–N(3)
118.21(10), C(1)–Mo(1)–N(3) 79.83(10), N(2)–Mo(1)–N(3) 72.92(8),
N(1)–Mo(1)–N(3) 142.86(8).
3
although of poor quality, showed the presence of the salt [Mo(g -
methallyl)(CO)2(NCMe)3]BArꢀ4 (4) (along with a molecule of
CH2Cl2), the fac disposition of the three nitrile ligands in the
structure of the cation, and the orientation of the open face of
the allyl ligand pointing toward the two CO ligands, as in most
3
[Mo(g -allyl)(CO)2L3] compounds.
When chloride abstraction is carried out using silver tri-
flate, as described above, the resulting solution is, given the
lability of both acetonitrile and triflate ligands, most likely a
3
3
mixture of [Mo(g -methallyl)(CO)2(NCMe)3]OTf and [Mo(g -
methallyl)(OTf)(CO)2(NCMe)2], whereas the employment of the
non-coordinating counteranion BArꢀ4 affords the tris(nitrile) 4
as the single product.
Compound 4 can be used as precursor for the synthesis of
3
other cationic [Mo(g -allyl)(CO)2L3]+ complexes. For instance,
the reaction of 4 and CHTA afforded 3, and the reaction of 4
3
with terpy afforded [Mo(g -methallyl)(CO)2(terpy)]BArꢀ4, with
the same cation present in 2.
Similar strategies can be applied to the synthesis of com-
plexes with three nitrogen-donor monodentate ligands. Thus,
3
the solution generated from [Mo(g -allyl)Cl(CO)2(NCMe)2],
Fig. 2 Thermal ellipsoid plot ◦(30%) of the cation of 3. Selected
AgOTf and MeCN (see above) reacted with three equivalents
˚
bond lengths (A) and angles ( ): Mo(1)–C(2) 1.85(4), Mo(1)–C(1)
3
of imidazole (im) to afford [Mo(g -allyl)(CO)2(im)3]OTf (5) (see
1.86(3), Mo(1)–C(6) 2.13(2), Mo(1)–N(2) 2.18(2), Mo(1)–N(1)
2.19(2), Mo(1)–N(3) 2.192(16), Mo(1)–C(5) 2.30(2), Mo(1)–C(7)
2.30(3); C(2)–Mo(1)–C(1) 81(2), C(2)–Mo(1)–C(6) 98.9(17), C(1)–
Mo(1)–C(6) 99.5(14), C(2)–Mo(1)–N(2) 91.9(16), C(1)–Mo(1)–N(2)
91.3(12), C(6)–Mo(1)–N(2) 165.8(10), C(2)–Mo(1)–N(1) 172.8(16),
C(1)–Mo(1)–N(1) 99.4(18), C(6)–Mo(1)–N(1) 88.2(15), N(2)–
Mo(1)–N(1) 80.9(13), C(2)–Mo(1)–N(3) 95.6(18), C(1)–Mo(1)–N(3)
170.2(14), C(6)–Mo(1)–N(3) 90.0(8), N(2)–Mo(1)–N(3) 79.6(9),
N(1)–Mo(1)–N(3) 82.7(7).
Scheme 3), which was characterized spectroscopically and by
X-ray diffraction (see Fig. 3).9,13 The spectroscopic data of this
cationic complex indicate a rigid structure like that found in the
1
solid; thus, the H NMR spectrum of 5 contains two sets of
imidazole signals, attributed to the two equivalent im ligands
each trans to one carbonyl, and to the single im ligand trans to
the allyl group. This behavior contrasts with the observation of
3
a single set of nitrile signals for [Mo(g -allyl)(CO)2(NCMe)3]+,12
The results of the solid state structure determinations reveal
that both nitrogen-donor ligands are coordinated in a tridentate
mode. As a result of their different coordination geometries
(see above), the two CO ligands are equivalent in 3 (due to
the presence of a mirror plane) and inequivalent in 2 (one CO
is trans to the allyl, and the other trans to one of the nitrogen
atoms). These structural features are consistent with the solution
13C NMR spectra, containing two carbonyl signals for 2 and
only one for 3. Thus, the structure of 3 is similar to those of
attributed to a dynamic process in solution.
When planning to synthesize an analogous tris(pyrazole)
complex, we noticed literature references to the insertion of the
N–H bonds of pyrazoles across the triple bond of coordinated
nitriles;14 thus, we endeavoured to design a nitrile-free synthetic
procedure. We found that a solution of molybdenum carbonyl
that has been refluxed for several hours in tetrahydrofuran
(THF) until the 1981 cm−1 band of Mo(CO)6 is absent, reacts
instantaneously with allyl bromide. The IR spectrum of the
resulting solution shows two bands of similar intensity, suggest-
3
previously characterized [Mo(g -allyl)(CO)2L3] complexes, all
3
3
of which showed fac-{Mo(g -allyl)(CO)2} moieties,10 whereas
ing the presence of the species [Mo(g -allyl)Br(CO)2(THF)2],
D a l t o n T r a n s . , 2 0 0 5 , 8 8 4 – 8 8 8
8 8 5

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Scheme 3
type of dmpz ligand, separate singlets are observed for the two
methyl susbtituents, a fact that indicates lack of rapid pyrazole
exchange.16 The solid state structure of the adduct 6·THF was
determined by X-ray diffraction (see Fig. 4).9
Fig. 3 Thermal ellipsoid plot◦ (30%) of the cation of 5. Selected
˚
bond lengths (A) and angles ( ): Mo(1)–C(2) 1.936(8), Mo(1)–C(1)
1.941(11), Mo(1)–C(4) 2.202(10), Mo(1)–N(1) 2.232(6), Mo(1)–N(5)
2.283(7), Mo(1)–N(3) 2.296(6), Mo(1)–C(5) 2.325(8), Mo(1)–C(3)
2.322(10); C(2)–Mo(1)–C(1) 81.3(4), C(2)–Mo(1)–C(4) 101.0(4),
C(1)–Mo(1)–C(4) 104.2(4), C(2)–Mo(1)–N(1) 86.1(3), C(1)–Mo(1)–
N(1) 90.2(3), C(4)–Mo(1)–N(1) 164.7(3), C(2)–Mo(1)–N(5) 96.9(3),
C(1)–Mo(1)–N(5) 169.9(3), C(4)–Mo(1)–N(5) 85.9(4), N(1)–Mo(1)–
N(5) 79.7(2), C(2)–Mo(1)–N(3) 167.5(3), C(1)–Mo(1)–N(3) 94.3(3),
N(1)–Mo(1)–N(3) 82.2(2), N(5)–Mo(1)–N(3) 85.3(2).
Fig. 4 Thermal ellipsoid plot (30%) of the adduct between THF and
the cation of 6. Hydrogen atoms were omitted for clarity. Selected
◦
˚
bond lengths (A) and angles ( ): Mo(1)–C(2) 1.941(7), Mo(1)–C(1)
1.954(6), Mo(1)–C(4) 2.201(5), Mo(1)–N(5) 2.213(4), Mo(1)–N(1)
2.310(4), Mo(1)–C(5) 2.321(6), Mo(1)–C(3) 2.327(6), Mo(1)–N(3)
2.334(4); C(2)–Mo(1)–C(1) 80.0(3), C(1)–Mo(1)–C(4) 101.6(2),
C(2)–Mo(1)–N(5) 90.0(2), C(1)–Mo(1)–N(5) 90.9(2), C(4)–Mo(1)–N(5)
164.0(2), C(2)–Mo(1)–N(1) 167.6(2), C(1)–Mo(1)–N(1) 94.8(2),
C(4)–Mo(1)–N(1) 90.1(2), N(5)–Mo(1)–N(1) 78.73(15), C(2)–
Mo(1)–C(5) 67.9(3), C(1)–Mo(1)–C(5) 105.3(2), C(4)–Mo(1)–C(5)
35.8(2), N(5)–Mo(1)–C(5) 149.1(2), N(1)–Mo(1)–C(5) 124.6(2), C(2)–
Mo(1)–C(3) 108.1(2), C(2)–Mo(1)–N(3) 93.4(2), C(1)–Mo(1)–N(3)
169.7(2), C(4)–Mo(1)–N(3) 87.41(19), N(5)–Mo(1)–N(3) 81.17(15),
N(1)–Mo(1)–N(3) 90.07(15).
which was found to be too unstable to be isolated or fur-
ther characterized. However, addition of NaBArꢀ4 and three
equivalents of 3,5-dimethylpyrazole (dmpz) afforded the new
3
compound [Mo(g -allyl)(CO)2(dmpz)3]BArꢀ4 (6) (Scheme 4).15
1
The H NMR spectrum of 6, like that of 5, displays a 1 : 2
pattern for the pyrazole signals, consistent with the existence of
molecules rigid in solution at room temperature with a structure
such that two dmpz ligands are each trans to a CO ligand, the
third dpmz being trans to the allyl group. Moreover, for each
Experimental
General conditions were given elsewhere.6
Syntheses
[Mo(g3-methallyl)(CO)2(terpy)]OTf (2). AgOTf (0.077 g,
3
0.236 mmol) was added to a solution of [Mo(g -methallyl)-
Cl(CO)2(NCMe)2] (1) (0.100 g, 0.30 mmol) in CH2Cl2/MeCN
(20 mL/0.3 mL), the mixture was stirred in the dark for
15 min and filtered through diatomaceous earth. Addition of
terpy (0.070 g, 0.30 mmol) to this solution caused a color
change from orange to purple. After stirring for 15 min, in
vacuo concentration and precipitation with hexane, a purple
microcrystalline solid was obtained. By slow diffusion of hexane
into a concentrated solution of 2 in CH2Cl2, suitable crystals for
Scheme 4
8 8 6
D a l t o n T r a n s . , 2 0 0 5 , 8 8 4 – 8 8 8

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an X-ray determination were obtained. Yield: 0.165 g, 90%.
Anal. Calcd. for C22H18F3MoN3O5S: C, 44.83; H, 3.07; N, 7.13.
Found: C, 44.54; H, 3.32; N, 7.62%. IR (CH2Cl2): 1965, 1874
[Mo(g3-allyl)(CO)2(dmpz)3]BArꢀ4 (6). A solution of [Mo-
(CO)6] (0.100 g, 0.38 mmol) in THF was refluxed until disap-
pearance of the m(CO) band of the starting material (1981 cm−1,
ca. 8 hours). After reaching room temperature, allyl bromide
(0.30 mL, 3.80 mmol) was added and the solution was stirred
for 15 min. At this point, the IR spectrum of the solution
displays two strong bands at 1942 and 1856 cm−1. The mixture
was concentrated to ca. 0.5 mL, CH2Cl2 (20 mL), NaBArꢀ4
(0.337 g, 0.38 mmol) and dmpz (0.110 g, 1.14 mmol) were added,
and the mixture was stirred for 5 min. After filtration through
diatomaceous earth, concentration under vacuum and addition
of hexane caused the precipitation of a yellow microcrystalline
solid. Slow diffusion of hexane into a concentrated solution
of 6 in CH2Cl2 at −20 ◦C afforded crystals, one of which
has been used for the structural determination by means
of X-ray diffraction. Yield: 0.332 g, 63%. Anal. Calcd. for
C52H41BF24MoN6O2·THF: C, 47.48; H, 3.49; N, 5.93. Found:
C, 47.73; H, 3.89; N, 5.91%. IR (CH2Cl2): 1951, 1863 (mCO). 1H
NMR (CD2Cl2, ppm): 9.99 [s br, 3H, dmpz], 7.70 [m, 8H, Ho],
7.54 [m, 4H, Hp], 6.06 [s, 1H, dmpz], 5.97 [s, 2H, dmpz], 4.22
[m, 1H, Hc of allyl], 3.05 [d (6.25), 2H, Hs], 2.26 [s, 6H, dmpz],
2.16 [s, 6H, dmpz], 1.99 [s, 3H, dmpz], 1.95 [s, 6H, dmpz], 1.49 [d
(9.10), 2H, Ha]. 13C NMR (CD2Cl2, ppm): 224.2 [s, CO], 162.1[q
(49.9), Ci], 158.4, 156.1, 146.9, 144.9 [s, dmpz], 135.2 [s br, Co],
129.2 [qq (2JCF = 31, 4JCF = 3), Cm], 124.9 [q (272), CF3], 117.9
[s, Cp], 109.4, 108.7 [s, dmpz], 71.9 [s, C2 of allyl], 60.7 [s, C1 and
C3 of allyl], 15.5 [s, dmpz], 14.3 [s, dmpz], 11.8 [s, dmpz].
1
(mCO). H NMR (CD2Cl2, ppm): 8.60 [m, 2H, terpy], 8.55 [m,
2H, terpy], 8.48 [m, 2H, terpy], 8.37 [m, 1H, terpy], 8.11 [m,
2H, terpy], 7.47 [m, 2H, terpy], 3.57 [s, 2H, Hs], 2.42 [s, 2H, Ha],
0.86 [s, 3H, methallyl]. 13C NMR (CD2Cl2, ppm): 237.0, 225.6
[s, CO], 156.25, 155.7, 152.9, 140.4, 139.8, 127.2, 124.9 [s, terpy],
119.9 [s, C2 of methallyl], 71.3 [s, C1 and C3 of methallyl], 19.8
[s, CH3 of methallyl].
[Mo(g3-methallyl)(CO)2(CHTA)]BArꢀ4 (3). NaBArꢀ4 (0.541 g,
0.61 mmol) was added to a solution of 1 (0.200 g, 0.61 mmol)
in a mixture of CH2Cl2/MeCN (20 mL/0.3 mL). After stirring
for 5 min and filtration through diatomaceous earth, CHTA
(0.079 g, 0.61 mmol) was added and the solution was stirred for
15 min. In vacuo concentration and addition of hexane caused
the precipitation of 3 as a microcrystalline yellow solid, which
was washed with hexane and dried under vacuum. The crystal
employed for the structure determination of 3 by means of X-
ray diffraction was obtained by slow diffusion of hexane into
a concentrated solution of 3 in CH2Cl2. Yield: 0.690 g, 94%.
Anal. Calcd. for C44H34BF24MoN3O2: C, 44.06; H, 2.85; N, 3.50.
Found: C, 44.32; H, 3.06; N, 3.28%. IR (CH2Cl2): 1954, 1864
(mCO). 1H NMR (CD2Cl2, ppm): 7.74 [m, 8H, Ho], 7.58 [m, 4H,
Hp], 3.54 [s br, 3H, CHTA], 2.80 [s br, 6H, NH2], 2.65 [s, 2H,
Hs], 2.20 [s, 3H, methallyl], 1.82 [m, 6H, CHTA], 1.18 [s, 2H,
Ha]. 13C NMR (CD2Cl2, ppm): 222.2 [s, CO], 162.1[q (49.9), Ci],
4
135.1 [s br, Co], 129.1 [qq (2JCF = 31, JCF = 3), Cm], 126.1 [q
(272), CF3], 117.8 [s, Cp], 79.6 [s, C2 of methallyl], 55.1 [s, C1 and
C3 of methallyl], 42.8 [s, CHTA], 34.0 [s, CHTA], 19.9 [s, CH3 of
methallyl].
X-Ray crystallography
A suitable crystal was attached to a glass fibre and transferred
to a Bruker AXS SMART 1000 diffractometer with graphite
monochromatized Mo-Ka X-radiation and a CCD area detector.
A hemisphere of reciprocal space was collected up to 2h = 48.6◦.
Raw frame data were integrated with the SAINT17 program.
The structure was solved by direct methods with SHELXTL.18
A semi-empirical absorption correction was applied with the
program SADABS.19 All non-hydrogen atoms were refined
anisotropically. For compound 5 an incipient disorder was
found to affect one of the two independent molecules (Molecule
2, numbered Mo51 onwards). No alternative position for the
methallyl and carbonyl carbons could be obtained to model
the disorder. However, a correct refinement was obtained by
restraining (with the intruction SAME) the distances within
Molecule 2 to be equal to those within the well defined
Molecule 1. Hydrogen atoms were set in calculated positions
and refined as riding atoms, with a common thermal parameter.
All calculations and graphics were made with SHELXTL.
CCDC reference numbers 254975, 254976, 254977 and 254978
for compounds 2, 3, 5 and 6 respectively.
[Mo(g3-methallyl)(CO)2(NCMe)3]BArꢀ4 (4). NaBArꢀ4 (0.266 g,
0.3 mmol) was added to a solution of 1 (0.100 g, 0.30 mmol) in
a mixture of CH2Cl2/MeCN (20 mL/0.3 mL). After stirring for
15 min, the mixture was filtered through diatomaceous earth,
in vacuo concentration and precipitation with hexane gave 4 as
a yellow microcrystalline solid. Slow diffusion of hexane into a
concentrated solution of 4 in CH2Cl2 at −20 ◦C afforded yellow
crystals, one of which was used for a structure determination
by X-ray diffraction analysis. Yield: 0.300 g, 83%. Anal. Calcd.
for C44H28BF24MoN3O2: C, 44.28; H, 2.36; N, 3.52%. Found: C,
43.82; H, 2.59; N, 3.25. IR (CH2Cl2): 1975, 1896 (mCO). 1H NMR
(CD2Cl2, ppm): 7.77 [m, 8H, Ho], 7.62 [m, 4H, Hp], 3.34 [s, 2H,
Hs], 2.34 [s, 9H, CH3CN], 2.17 [s, 2H, Ha], 1.46 [s, 3H, methallyl].
13C NMR (CD2Cl2, ppm): 219.8 [s, CO], 162.1[q (49.9), Ci], 135.1
4
[s br, Co], 129.1 [qq (2JCF = 31, JCF = 3), Cm], 126.1 [q (272),
CF3], 117.8 [s, Cp], 86.3 [s, C2 of methallyl], 59.7 [s, C1 and C3 of
methallyl], 20.25 [s, CH3 of methallyl], 3.55 [s, CH3CN].
See http://www.rsc.org/suppdata/dt/b4/b417330e/ for cry-
stallographic data in CIF or other electronic format.
[Mo(g3-allyl)(CO)2(im)3]OTf (5). A mixture of AgOTf
(0.067 g, 0.26 mmol) and [Mo(g -allyl)Cl(CO)2(MeCN)2]
3
(0.075 g, 0.24 mmol) in CH2Cl2/MeCN (20 mL/0.3 mL) was
stirred for 15 min. After filtration through diatomaceous earth,
im (0.049 g, 0.72 mmol) was added and the resulting solution was
stirred for 1 hour. In vacuo concentration and addition of hexane
caused the precipitation of 5 as a yellow microcrystalline solid,
which was washed with hexane and dried under vacuum. Slow
diffusion of hexane into a concentrated solution of 5 in THF
afforded crystals, one of which has been used for the structural
determination by means of X-ray diffraction. Yield: 0.120 g,
92%. Anal. Calcd. for C15H17F3MoN6O5S: C, 32.97; H, 3.17; N,
15.37. Found: C, 33.12; H, 3.32; N, 15.52%. IR (CH2Cl2): 1940,
1846 (mCO). 1H NMR (CD6CO, ppm): 12.18 [s br, 3H, im], 7.89
[s, 1H, im], 7.80 [s, 2H, im], 7.33 [s, 1H, im], 7.29 [s, 2H, im], 6.88
[s, 2H, im], 6.75 [s, 1H, im], 4.20 [m, 1H, 1H, Hc of allyl], 3.02
[d (6.25), 2H, Hs], 1.38 [d (9.10), 2H, Ha]. 13C NMR (CD6CO,
ppm): 225.7 [s, CO], 140.7, 138.8, 130.2, 129.1, 118.3, 118.1
[s, im], 70.8 [s, C2 of allyl], 59.1 [s, C1 and C3 of allyl].
Acknowledgements
We thank Dr Fernando Villafan˜e (Universidad de Valladolid)
for disclosing to us his results prior to publication, and
Ministerio de Ciencia y Tecnolog´ıa for support of this work
(Grants BQU2003-08649 and BQU2002-03414).
Notes and references
1 (a) Y. D. Ward, L. A. Villanueva, G. D. Allred and L. S. Liebe-
skind, Organometallics, 1996, 15, 4201; (b) A. J. Pearson and
E. Schoffers, Organometallics, 1997, 16, 5365; (c) M. P. T. Sjo¨gren,
˚
H. Frisell, B. Akermark, P. Norrby, L. Eriksson and A. Vitagliano,
Organometallics, 1997, 16, 9–42.
2 (a) B. M. Trost and M. Lautens, J. Am. Chem. Soc., 1982, 104, 5543;
(b) B. M. Trost and M. Lautens, J. Am. Chem. Soc., 1987, 109, 1469;
(c) B. M. Trost and I. Hachiya, J. Am. Chem. Soc., 1998, 120, 1104;
D a l t o n T r a n s . , 2 0 0 5 , 8 8 4 – 8 8 8
8 8 7

View Article Online
−1
¯
(d) G. Frank and A. Pfaltz, Org. Lett., 1999, 1, 141; (e) G. C. Lloyd-
Jones, S. W. Krska, D. L. Hughes, L. Gouriou, V. D. Bonnet, D. Jack,
Y. Sun and R. A. Reamer, J. Am. Chem. Soc., 2004, 126, 702.
3 D. R. Van Staveren, E. Bill, E. Bothe, M. Buhl, T. Weyhermuller and
N. Metzler-Nolte, Chem. Eur. J., 2002, 8, 1649.
T = 296(2) K, space group = P1, Z = 2, l(Mo-Ka) = 0.333 mm
,
13941 reflections collected, 8784 unique (Rint = 0.0265), R1 = 0.0624,
wR2 = 0.1593.
10 J. R. Ascenso, C. G. de Azevedo, M. J. Calhorda, M. A. A. F. De
C. T. Carrondo, P. Costa, A. R. Dias, M. G. B. Drew, V. Fe´lix, A. M.
Galvao and C. C. Romao, J. Organomet. Chem., 2001, 632, 197.
11 Few molybdenum carbonyl complexes containing the terpy ligand
have been structurally characterized, see: (a) N. Aimeloglou, P. K.
Baker, M. G. B. Drew, B. Glaeser, F. Holland and M. M. Meehan,
J. Organomet. Chem., 2000, 604, 191 and references therein. The
complex [Mo(CO)4(terpy)] features a bidentate terpy ligand; (b) E. W.
Abel, K. G. Orrell, A. G. Osborne, H. M. Pain and V. Sik, J. Chem.
Soc., Dalton Trans., 1994, 111.
4 S. Trofimenko, J. Am. Chem. Soc., 1970, 92, 5118.
5 B. J. Brisdon, M. Cartwright, A. G. W. Hodson, M. F. Mahon and
K. C. Molloy, J. Organomet. Chem., 1992, 435, 319.
6 (a) D. Morales, J. Pe´rez, L. Riera, V. Riera, R. Corzo-Sua´rez,
S. Garc´ıa-Granda and D. Miguel, Organometallics, 2002, 21, 1540;
(b) D. Morales, M. E. N. Clemente, J. Pe´rez, L. Riera, V. Riera
and D. Miguel, Organometallics, 2002, 21, 4934. We have found that
3
3
the exact nature of the g -allyl ligand (i.e., g -C3H5(plain allyl) or
methallyl) does not make any observable difference in the chemistry
reported here. Therefore, we have preferred to include for each kind
of complex only one compound, either the allyl or the methallyl
derivative, selecting in each case the compound that afforded crystals
most suitable for X-ray crystallography.
12 B. J. Brisdon and M. Cartwrigth, J. Organomet. Chem., 1979, 164,
83.
13 Molybdenum carbonyl complexes containing imidazole ligands are
scarce, see: (a) W. Beck, J. C. Weis and J. Wieczorek, J. Organomet.
Chem., 1971, 30, 89; (b) R. B. Kin and K. N. Chen, Inorg. Chem.,
1977, 16, 3372; (c) T. Tatsumi, H. Tominaga, M. Hidai and Y. Uchida,
J. Organomet. Chem., 1980, 199, 63; (d) P. K. Baker, D. Kendrick and
W. Beck, J. Organomet. Chem., 1987, 333, 237; (e) P. K. Baker and
M. van Kampen, Inorg. Chim. Acta, 1993, 204, 247.
14 (a) C. J. Jones, J. A. McCleverty and A. S. Rothin, J. Chem. Soc.,
Dalton Trans., 1986, 109; (b) P. Gowindaswamy, Y. Mozharivskyj and
M. R. Kollipara, J. Organomet. Chem., 2004, 689, 3265; (c) a similar
behavior has been found in molybdenum allyldicarbonyl complexes:
F. Villafan˜e and M. Arroyo, personal communication.
15 Neutral allyl-dicarbonyl complexes with two pyrazole ligands are
known, see: (a) F. A. Cotton and R. L. Luck, Acta Crystallogr.,
Sect. C, 1990, 46, 138; (b) P. Paredes, F. Villafan˜e and D. Miguel,
Eur. J. Inorg. Chem., 2003, 995.
16 G. A. Ardizzoia, G. LaMonica, A. Maspero, M. Moret and
N. Massiocchi, Eur. J. Inorg. Chem., 1998, 1503.
7 T. Bowen, R. P. Planalp and M. W. Brechbiel, Bioorg. Med. Chem.
Lett., 1995, 6, 807.
8 The cation of 3 is the first molydenum complex of CHTA and
the compound [Cr(CO)3(CHTA)] is the only previously reported
carbonyl complex of CHTA: J. Y. Yang, M. P. Shores, J. J. Sokol
and J. R. Long, Inorg. Chem., 2003, 42, 1403.
9 Crystal data: for compound 2: C22H18F3MoN3O5S, M = 589.39,
˚
monoclin◦ic, a = 8.3982(16), b = 24.889(5), c = 10.886(2) A, b =
3
˚
92.241(3) , U = 2273.7(8) A , T = 299(2) K, space group = P2(1)/n,
Z = 4, l(Mo-Ka) = 0.734 mm−1, 14197 reflections collected, 3275
unique (Rint = 0.0266), R1 = 0.0248, wR2 = 0.0622. For compound
3: C44H34BF24MoN3O2, M = 1199.49, trigonal, a = 16.224(6), b =
3
˚
˚
16.224(6), c = 15.949(8) A, U = 3636(3) A , T = 293(2) K, space
group = P3(2), Z = 3, l(Mo-Ka) = 0.404 mm−1, 17474 reflections
collected, 7015 unique (Rint = 0.0580), R1 = 0.0829, wR 2= 0.2042.
For compound 5: C15H17F3MoN6O5S, M = 546.35, orthorhombic,
17 SAINT+. SAX area detector integration program. Version 6.02,
˚
a = 21.900(5), b = 26.529(6), c = 7.3441(16) A, U = 4266.8(16)
Bruker AXS, Inc., Madison, WI, 1999.
3
˚
A , T = 296(2) K, space group = Pna2(1), Z = 8, l (Mo-Ka) =
18 G. M. Sheldrick, SHELXTL, An integrated system for solving,
refining, and displaying crystal structures from diffraction data. Version
5.1, Bruker AXS, Inc., Madison, WI, 1998.
19 G. M. Sheldrick, SADABS, Empirical Absorption Correction Pro-
gram, University of Go¨ttingen, Go¨ttingen, Germany, 1997.
0.778 mm−1, 18771 reflections collected, 6065 unique (Rint = 0.0442),
R1 = 0.0472, wR2 = 0.1136. For compound 6: C56H49BF24MoN6O3,
M = 1416.76, triclinic, a = 13.209(3), b = 13.564(3), c = 17.510(4)
◦
3
˚
˚
A, a = 86.569(4), b = 79.445(4), c = 89.789(5) , U = 3078.6(12) A ,
8 8 8
D a l t o n T r a n s . , 2 0 0 5 , 8 8 4 – 8 8 8