Synthesis of Group 6 metal carbonyl complexes with iminophosphine ligands: Crystal structure of [Mo(Co)4(o-Ph2PC6H4-CH=NMe)]

Article abstract of DOI:10.1016/S0020-1693(00)00165-1

The synthesis of new molybdenum and tungsten carbonyl complexes with the mixed donor bidentate ligands o-Ph₂PC₆H₄-CH=NR is described. Two series of complexes [M(CO)₄(o-Ph₂PC₆H₄-CH=NR)] (M = Mo; R = Me (1a), Et (2a), (i)Pr (3a), (t)Bu (4a), NH-Me (5a). M = W; R = Me (1b), Et (2b), (i)Pr (3b), (t)Bu (4b), NH-Me (5b)) have been prepared by direct reaction of the ligands with the corresponding precursors cis-[M(CO)₄(pip)₂] (M = Mo or W; pip = piperidine NHC₅H₁₀). The new complexes were characterized by partial elemental analyses and spectroscopic methods (IR, ¹H, ¹³C and ³¹P NMR). The molecular structure of compound 1a (monoclinic, P2₁/n) was determined by a single-crystal diffraction study. (C) 2000 Elsevier Science S.A.

Full text of DOI:10.1016/S0020-1693(00)00165-1

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Inorganica Chimica Acta 306 (2000) 168–173
Synthesis of Group 6 metal carbonyl complexes with
iminophosphine ligands: crystal structure of
[Mo(CO)4(o-Ph2PC6H4–CHꢀNMe)]
Gregorio Sa´nchez a,*, Jose´ L. Serrano b, Carmen M. Lo´pez a, Joaqu´ın Garc´ıa a,
Jose´ Pe´rez a, Gregorio Lo´pez a
a Departamento de Qu´ımica Inorga´nica, Uni6ersidad de Murcia, 30071 Murcia, Spain
Departamento de Ingenier´ıa Minera, Geolo´gica y Cartogra´fica. Area de Qu´ımica Inorga´nica, Uni6ersidad Polite´cnica de Cartagena,
b
´
30203 Cartagena, Spain
Received 25 February 2000; accepted 10 May 2000
Abstract
The synthesis of new molybdenum and tungsten carbonyl complexes with the mixed donor bidentate ligands o-Ph2PC6H4–
i
t
CHꢀNR is described. Two series of complexes [M(CO)4(o-Ph2PC6H4–CHꢀNR)] (M=Mo; R=Me (1a), Et (2a), Pr (3a), Bu
i
t
(4a), NH–Me (5a). M=W; R=Me (1b), Et (2b), Pr (3b), Bu (4b), NH–Me (5b)) have been prepared by direct reaction of the
ligands with the corresponding precursors cis-[M(CO)4(pip)2] (M=Mo or W; pip=piperidine NHC5H10). The new complexes
1
were characterized by partial elemental analyses and spectroscopic methods (IR, H, 13C and 31P NMR). The molecular structure
of compound 1a (monoclinic, P21/n) was determined by a single-crystal diffraction study. © 2000 Elsevier Science S.A. All rights
reserved.
Keywords: Molybdenum complexes; Tungsten complexes; Carbonyl complexes; Iminophosphine complexes; Crystal structures
1. Introduction
metals [10,11,13–21] but have not yet been studied
when coordinating Group 6 metals.
Furthermore, some N,P-ligands were involved years
ago in mechanistic studies of chelate ring opening in
metal carbonyl complexes of the type [M(CO)4(N–P)]
where M=Cr, Mo and W, and N–P=Ph2PCH2-
CH2N(CH3)2, Ph2PCH2CH2NPh2, Ph2PCH2CH2NH2
and Ph2PCH2CH2CH2N(CH3)2 [22,23], showing that
the labile nitrogen-donor group readily dissociated
from the coordination sphere, allowing the entry of a
new ligand.
Since then only a few examples of metal carbonyls
with pyridylphosphines [24–31] have been reported,
compared with the extensive and well documented bib-
liography of their phosphine analogues.
A recent surge of interest in carbonyl complexes with
chelating phosphines is due to their ability to undergo
ring-opening in order to facilitate isomerization reac-
tions [32]. In this sense, the study of Group 6 carbonyl
complexes containing iminophosphine ligands with the
binding properties mentioned above should be of maxi-
There has recently been considerable interest in the
chemistry of polydentate ligands with both ‘soft’ phos-
phorus and ‘hard’ nitrogen donor atoms [1–8], due in
part to the variety of coordination possibilities dis-
played by them compared with classical P–P or N–N
ligands [9]. Since the hard-ligand components can read-
ily dissociate from a soft metal centre generating a
vacant site on the metal ion for potential substrate
binding, these N,P-ligands have also been investigated
in order to design and develop new homogeneous cata-
lytic systems [10–17]. Among the most studied ligands
with this characteristic are the pyridylphosphines and
the iminophosphines that we present here, which have
been widely reported since 1992 in complexes of several
* Corresponding author. Tel.: +34-968-367 454; fax: +34-968-
364 148.
E-mail address: gsg@fcu.um.es (G. Sa´nchez).
0020-1693/00/$ - see front matter © 2000 Elsevier Science S.A. All rights reserved.
PII: S0020-1693(00)00165-1

G. Sa´nchez et al. / Inorganica Chimica Acta 306 (2000) 168–173
169
mum interest. On the other hand, the fact that their
fundamental chemistry remains unexplored and that
related examples have been recently reported [33–35]
encouraged us to investigate in this field.
precipitation of the new complexes, which were filtered
off, air dried and recrystallized from dichloromethane–
hexane.
[Mo(CO)4(o-Ph2PC6H4–CHꢀNMe)] (1a) was ob-
tained in 72% yield. Anal. Calc. for C24H18NPO4Mo: C,
56.4; H, 3.5; N, 2.7. Found: C, 56.2; H, 3,6; N, 3.0%.
M.p. 167°C dec. 1H NMR (CDCl3, 20°C) l 3.67 (s, 1H,
Me), 6.79 (m, 1H, H3), 7.34 (m, 13H, H4,H5,H6; Ph),
8.15 (s, 1H, CHꢀN). 31P-{1H}NMR (CDCl3, 20°C) l
35.97 (s).
It is well known that to carry out carbonyl substitu-
tion reactions in Group 6 metal carbonyls, disubstituted
precursors like cis-[M(CO)4(pip)2] [36] are preferred to
enable the reaction to proceed smoothly in high yields,
instead of direct reaction of the metal hexacarbonyl.
Recent examples [34,37–40] where simple substitution
reactions have occurred confirm the convenience of
using the piperidine complex as metallic precursor.
Here we report the synthesis and characterization of
complexes of the type [M(CO)4(o-Ph2PC6H4–CHꢀNR)]
[Mo(CO)4(o-Ph2PC6H4–CHꢀNEt)] (2a) was obtained
in 83% yield. Anal. Calc. for C25H20NPO4Mo: C, 57.2;
H, 3.8; N, 2.7. Found: C, 57.0; H, 4.0; N, 2.8%. M.p.
151°C dec. 1H NMR (CDCl3, 20°C) l 1.01 (t, 3H,CH3–,
i
t
(M=Mo, W; R=Me, Et, Pr, Bu, NH–Me), prepared
by direct reaction between iminophosphine ligands and
the precursors cis-[M(CO)4(pip)2].
JHH=7.0), 3.82 (cd, 2H, –CH2–, JHH=7.0), 6.80 (m,
1H, H3), 7.48 (m, 13H, H4,H5,H6; Ph), 8.21 (s, 1H,
CHꢀN). 31P-{1H}NMR (CDCl3, 20°C) l 34.86 (s).
[Mo(CO)4(o-Ph2PC6H4–CHꢀNiPr)] (3a) was ob-
tained in 88% yield. Anal. Calc. for C26H22NPO4Mo: C,
57.9; H, 4.1; N, 2.6. Found: C, 57.8; H, 4.1; N, 2.7%.
M.p. 160°C dec. 1H NMR (CDCl3, 20°C) l 1.04 (d, 6H,
2CH3–, JHH=6.6), 4.17 (m, 1H,CH, JHH=6.6), 6.69
(m, 1H, H3), 7.37 (m, 13H, H4,H5,H6; Ph), 8.22 (d, 1H,
CHꢀN, JHP=2.1). 31P-{1H}NMR (CDCl3, 20°C) l
36.02 (s).
2. Experimental
C, H, and N analyses were carried out with a
Perkin–Elmer 240C microanalyser. IR spectra were
recorded on a Perkin–Elmer spectrophotometer 16F
PC FTIR, using Nujol mulls between polyethylene
sheets. NMR data were recorded on a Bruker AC 200E
(1H, 13C) or a Varian Unity 300 (1H, 13C, 31P) spec-
trometer. Decomposition temperatures were determined
on a Reichert microscope.
Reactions were carried out under a dinitrogen atmo-
sphere using standard Schlenk techniques. The pipe-
ridine precursors cis-[M(CO)4(pip)2] (M=Mo, W) were
prepared by the published method [36]. The iminophos-
phine ligands were prepared according to reported pro-
cedures [11] and all the solvents were dried by standard
methods before use.
[Mo(CO)4(o-Ph2PC6H4–CHꢀNtBu)] (4a) was ob-
tained in 86% yield. Anal. Calc. for C27H24NPO4Mo: C,
58.6; H, 4.4; N, 2.5. Found: C, 58.5; H, 4.2; N, 2.7%.
M.p. 138°C dec. 1H NMR (CDCl3, 20°C) l 1.13 (s, 9H,
3CH3–), 6.67 (m, 1H, H3), 7.26 (m, 13H, H4,H5,H6;
Ph), 8.29(d, 1H, CHꢀN, JHP=2,0).). 31P-{1H}NMR
(CDCl3, 20°C) l 33.96 (s).
[Mo(CO)4(o-Ph2PC6H4–CHꢀNNHMe)] (5a) was ob-
tained in 68% yield. Anal. Calc. for C24H19N2PO4Mo:
C, 54.8; H, 3.6; N, 5.3. Found: C, 54.5; H, 3.5; N, 5.4%.
M.p. 139°C dec. 1H NMR (CDCl3, 20°C) l 2.80 (d, 3H,
Me, JHH=5.1), 5.62 (m, 1H, NH, JHH=4.8), 6.74 (m,
1H, H3), 7.36 (m, 13H, H4,H5,H6; Ph), 7.51 (s, 1H,
CHꢀN). 31P-{1H}NMR (CDCl3, 20°C) l 36.55 (s).
[W(CO)4(o-Ph2PC6H4–CHꢀNMe)] (1b) was obtained
in 70% yield. Anal. Calc. for C24H18NPO4W: C, 48.1;
H, 3.0; N, 2.3. Found: C, 47.9; H, 3,1; N, 2.3%. M.p.
2.1. Preparation of the complexes
[M(CO)4(o-Ph2PC6H4–CHꢀNR)] (M=Mo; R=Me
i
t
(1a), Et (2a), Pr (3a), Bu (4a), NH–Me (5a).
i
t
M=W; R=Me (1b), Et (2b), Pr (3b), Bu (4b),
NH–Me (5b))
1
195°C dec. H NMR (CDCl3, 20°C) l 3.83 (s, 1H, Me),
The complexes were obtained by treating cis-
[M(CO)4(pip)2] (M=Mo, W) with the corresponding
iminophosphine (molar ratio 1:1) in dichloromethane
according to the following general method. To a
dichloromethane (10 ml) yellow solution of the precur-
sor [M(CO)4(pip)2] (0.310 mmol) was added the stoi-
chiometric amount of the previously prepared
iminophosphine dissolved in dichloromethane (10 ml).
The reaction mixture changed colour to orange–red
gradually and was refluxed for 30 min (Mo compounds)
or 1 h (W compounds). The hot solution was filtered
through celite and then concentrated under reduced
pressure to half volume. Addition of hexane caused
6.81 (m, 1H, H3), 7.35 (m, 13H, H4,H5,H6; Ph), 8.08 (s,
1H, CHꢀN). 31P-{1H}NMR (CDCl3, 20°C) l 24.88 (s;
with 183W satellites, JWP=241 Hz).
[W(CO)4(o-Ph2PC6H4–CHꢀNEt)] (2b) was obtained
in 80% yield. Anal. Calc. for C25H20NPO4W: C, 49.0;
H, 3.3; N, 2.3. Found: C, 48.9; H, 3.0; N, 2.4%. M.p.
182°C dec. 1H NMR (CDCl3, 20°C) l 0.99 (t, 3H,CH3–,
J
HH=7.5), 3.93 (cd, 2H, –CH2–, JHH=7.5), 6.81 (m,
1H, H3), 7.42 (m, 13H, H4,H5,H6; Ph), 8.14 (d, 1H,
CHꢀN, JHP=2.4). 31P-{1H}NMR (CDCl3, 20°C) l
24.93 (s; with 183W satellites, JWP=238 Hz).
[W(CO)4(o-Ph2PC6H4–CHꢀNiPr)] (3b) was obtained
in 73% yield. Anal. Calc. for C26H22NPO4W: C, 49.8;

170
G. Sa´nchez et al. / Inorganica Chimica Acta 306 (2000) 168–173
(CDCl3, 20°C) l 24.08 (s; with 183W satellites, JWP
240 Hz).
=
Table 1
Crystal data and structure refinement for 1a
[W(CO)4(o-Ph2PC6H4–CHꢀNNHMe)] (5b) was ob-
tained in 69% yield. Anal. Calc. for C24H19N2PO4W: C,
46.9; H, 3.1; N, 4.6. Found: C, 46.9; H, 3.3; N, 4.4%.
M.p. 172°C dec. 1H NMR (CDCl3, 20°C) l 2.84 (d, 3H,
Me, JHH=5.1), 5.64 (m, 1H, NH, JHH=5.4), 6.81 (m,
1H, H3), 7.38 (m, 13H, H4,H5,H6; Ph), 7.51 (s, 1H,
CHꢀN). 31P-{1H}NMR (CDCl3, 20°C) l 26.18 (s; with
183W satellites, JWP=242 Hz).
Empirical formula
Formula weight
C24H18MoNO4P
511.30
0.71073
monoclinic
P21/n
,
Wavelength (A)
Crystal system
Space group
Unit cell dimensions
,
a (A)
13.817(3)
10.785(2)
16.077(3)
90
106.38(3)
90
2298.5(8)
4
1.478
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
2.2. Crystal structure determination of
[Mo(CO)4(o-Ph2PC6H4–CHꢀNMe)] (1a)
3
,
Volume (A )
Z
Density (calculated) (Mg m−3
)
)
A single crystal of complex [Mo(CO)4(o-Ph2PC6H4–
CHꢀNMe)] (1a) (approximate dimensions 0.30×
0.30×0.30 mm was mounted on a Siemens P4
diffractometer. The crystallographic data are shown in
Table 1. Accurate cell parameters were determined by
least-squares fitting of 42 high-angle reflections. The
scan method was ꢀ–2q with the range of hkl (−175
h51, −135k51, −205l520) corresponding to
2qmax=55°. Empirical „-scan mode absorption correc-
tion was made. The structure was solved by direct
methods [41] and refined [42] by full-matrix least-
squares techniques using anisotropic thermal parame-
ters for non-H atoms. The final R factor was 0.0301
Absorption coefficient (mm−1
F(000)
0.669
1032
2.29 to 27.50
Theta range for data
collection (°)
Index ranges
−175h51, −135k51,
−205l520
5105
4040 [Rint=0.0159]
full-matrix least-squares on F2
4040/0/280
Reflections collected
Independent reflections
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I\2|(I)]
R indices (all data)
1.069
R1=0.0301, wR2=0.0767
R1=0.0344, wR2=0.0797
0.306 and −0.507
Largest diff. peak and hole
−3
,
(e A
)
(Rw=0.0767
where
w=1/[|2(Fo2)+(0.0315P)2+
1.41P] and P=Fo2+2Fc2)/3) over 3627 observed reflec-
tions (I\2|(I)).
H, 3.5; N, 2.2. Found: C, 49.7; H, 3.3; N, 2.0%. M.p.
180°C dec. 1H NMR (CDCl3, 20°C) l 1.02 (d, 6H,
2CH3–, JHH=6.6), 4.38 (m, 1H,CH, JHH=6.6), 6.77
(m, 1H, H3), 7.41 (m, 13H, H4,H5,H6; Ph), 8.18 (d, 1H,
CHꢀN, JHP=3.0). 31P-{1H}NMR (CDCl3, 20°C) l
25.43 (s; with 183W satellites, JWP=239 Hz).
3. Results and discussion
In dichloromethane, the disubstituted precursors cis-
[M(CO)4(pip)2] (M=Mo or W) react under mild condi-
tions with the corresponding iminophosphines
previously prepared in 1:1 molar ratio, affording the
expected compounds [M(CO)4(o-Ph2PC6H4–CHꢀNR)]
in good yield (Scheme 1). The new complexes are air
stable orange to red solids that show negligible molar
conductances and have been characterized by elemental
analysis, 1H, 31P{1H}, 13C{1H} NMR and IR spec-
[W(CO)4(o-Ph2PC6H4–CHꢀNtBu)] (4b) was obtained
in 81% yield. Anal. Calc. for C27H25NPO4W: C, 50.6;
H, 3.8; N, 2.2. Found: C, 50.5; H, 3.8; N, 2.4%. M.p.
145°C dec. 1H NMR (CDCl3, 20°C) l 1.24 (s, 9H,
3CH3–), 6.76 (m, 1H, H3), 7.41 (m, 13H, H4,H5,H6;
Ph), 8.34 (d, 1H, CHꢀN, JHP=2.7). 31P-{1H}NMR
Scheme 1.

G. Sa´nchez et al. / Inorganica Chimica Acta 306 (2000) 168–173
171
Table 2
IR a and {1H}13C (l ppm) data for the complexes [M(CO)4{P(o-C6H4–CHꢀN–R)Ph2}]
Complex
w(CHꢀN)
w(CO)
13C (SiMe4) b,c
1a
1622
2014, 1918, 1884, 1852, 1902(sh)
61.96 (d, 1C, Me, JCP=3.6)
168.32 (d, 1C, CHꢀN, JCP=4.4)
207.87 (d, 2C, C3,4, JCP=8.4)
216.61 (d, 1C, C1, JCP=32.8)
220.99 (d, 1C, C2, JCP=7.6)
2a
3a
4a
1614
1612
1598
2008, 1892, 1872, 1856
2010, 1904, 1888, 1864
2008, 1892, 1872, 1842
16.27 (s, 1C, CH3–)
67.71 (d, 1C, –CH2–, JCP=2.3)
168.25 (d, 1C, CHꢀN, JCP=3.8)
207.90 (d, 2C, C3,4, JCP=9.1)
216.57 (d, 1C, C1, JCP=33.6)
221.00 (d, 1C, C2, JCP=6.9)
22.29 (s, 2C, 2CH3–)
69.58 (s, 1C, CH)
165.57 (d, 1C, CHꢀN, JCP=4.6)
207.82 (d, 2C, C3,4, JCP=9.1)
216.93 (d, 1C, C1, JCP=33.6)
221.37 (d, 1C, C2, JCP=7.6)
31.18 (s, 3C, 3CH3–)
64.60 (s, 1C, C)
167.60 (d, 1C, CHꢀN, JCP=4.6)
207.75 (d, 2C, C3,4, JCP=8.3)
217.04 (d, 1C, C1, JCP=34.3)
221.29 (d, 1C, C2, JCP=7.7)
5a
1b
2b
1584
1586
1584
2014, 1916, 1892, 1856
35.18 (s, 1C, Me)
142.62 (d, 1C, CHꢀN, JCP=5.8)
207.52 (d, 2C, C3, 4, JCP=9.2)
216.19 (d, 1C, C1, JCP=31.3)
220.61 (d, 1C, C2, JCP=7.6)
2008, 1892, 1872, 1842, 1912(sh)
2002, 1910, 1880, 1850
64.17 (d, 1C, Me, JCP=3.4)
168.59 (d, 1C, CHꢀN, JCP=4.4)
202.26 (d, 2C, C3,4, JCP=6.9)
209.78 (d, 1C, C1, JCP=31.9)
211.26 (d, 1C, C2, JCP=5.3)
22.48 (s, 1C, CH3–)
70.09 (s, 1C, –CH2–)
168.33 (d, 1C, CHꢀN, JCP=4.7)
202.34 (d, 2C, C3,4, JCP=6.9)
209.84 (d, 1C, C1, JCP=31.9)
211.11 (d, 1C, C2, JCP=5.5)
3b
4b
5b
1606
1592
1582
2004, 1880, 1860, 1846, 1898(sh)
2002, 1876, 1842, 1770, 1864(sh), 1788(sh)
2010, 1906, 1886, 1850
22.31 (s, 2C, 2CH3–)
72.22 (s, 1C, CH)
165.48 (d, 1C, CHꢀN, JCP=4.6)
202.36 (d, 2C, C3,4, JCP=6.9)
210.35 (d, 1C, C1, JCP=32.5)
211.61 (d, 1C, C2, JCP=5.7)
31.60 (s, 3C, 3CH3–)
66.57 (s, 1C, C)
168.42 (d, 1C, CHꢀN, JCP=4.6)
202.30 (d, 2C, C3, 4, JCP=7, 3)
210.21 (d, 1C, C1, JCP=31.8)
210.95 (d, 1C, C2, JCP=5.0)
35.84 (d, 1C, Me)
143.74 (d, 1C, CHꢀN, JCP=4.1)
202.27 (d, 2C, C3,4, JCP=7.0)
209.49 (d, 1C, C1, JCP=30.2)
210.41 (d, 1C, C2, JCP=4.5)
a In Nujol (cm−1).
b In CDCl3 at 20°C.
c 31P–13C coupling constants in Hz.

172
G. Sa´nchez et al. / Inorganica Chimica Acta 306 (2000) 168–173
Fig. 1. Molecular structure of complex 1a.
troscopy (Table 2, Section 2). Compound 1a was fur-
ther characterized by a single-crystal X-ray diffraction
study; the structure is discussed later.
The IR spectra of all compounds show the four-band
pattern expected for the M(CO)4 framework of Cs
back-donation increases, the 13C chemical shift is
deshielded, in agreement with previously reported data
[43]. The usual trend in 31P–13C coupling constants in
phosphorus-substituted derivatives of molybdenum and
tungsten hexacarbonyls is also followed, all compounds
displaying considerably greater JPC for trans arrange-
ments than for the cis geometry [43,45].
symmetry (3A%+A%%) [43] together with
a single
medium band in the 1622–1582 cm−1 region, attibuted
to the CꢀN stretching vibration of the iminophosphine
ligand coordinated to Mo or W; this appears shifted to
lower frequencies than in the free ligand.
3.1. Molecular structure of
[Mo(CO)4(o-Ph2PC6H4–CHꢀNMe)] (1a)
1
The H NMR data are collected in Section 2. All the
spectra display the expected resonances for the
iminophosphine ligands [11], which are little perturbed
on complexation and appear in the range previously
observed on coordinating other metals [44]. The appre-
ciable coupling to the phosphorus atom exhibited by
the iminic proton is the only remarkable feature. The
31P NMR spectra of the new complexes show a singlet
resonance shifted downfield from the free ligand, ac-
The coordination about the central metal atom is a
distorted octahedron (Fig. 1). Selected bond distances
and angles are presented in Table 3. A large deviation
from ideal octahedral geometry is observed for the
P–Mo–N angle, for which a contraction from 90 to
77.78(7)° occurs. Small P–M–N angles also have been
Table 3
companied by 138W satellites in b-compounds (JWP
=
,
Selected bond lengths (A) and angles (°) for 1a
240 Hz).
Mo–C(22)
Mo–C(23)
Mo–C(21)
Mo–C(20)
Mo–N
1.947(3)
1.996(3)
2.024(3)
2.028(3)
2.279(2)
2.4977(8)
C(22)–Mo–C(23)
C(22)–Mo–C(21)
C(22)–Mo–C(20)
C(22)–Mo–P
C(23)–Mo–N
C(21)–Mo–N
90.07(14)
88.73(13)
84.19(15)
100.25(10)
92.12(12)
93.90(11
Identification of the new complexes is substantiated
unambiguously by 13C{1H} NMR spectroscopy. Se-
lected data from the spectra are listed in Table 2
focusing on the aliphatic region, the iminic position of
the iminophosphine ligand and the carbonyl carbon
resonances. In this last region three resonances are
observed at approximately 221, 217 and 208 ppm in
molybdenum compounds (211, 210 and 202 ppm in
tungsten complexes) assigned to C2, C1 and the equiva-
lents C3 and C4 respectively. Thus, as M“CO p
Mo–P
C(20)–Mo–N
N–Mo–P
C(21)–Mo–P
C(20)–Mo–P
93.27(14)
77.78(7)
87.21(11)
96.64(10)
C(21)–Mo–C(20)
C(22)–Mo–N
C(23)–Mo–P
172.44(15)
176.62(13)
168.74(9)
88.53(16)
C(23)–Mo–C(21)
C(23)–Mo–C(20) 88.83(14)

G. Sa´nchez et al. / Inorganica Chimica Acta 306 (2000) 168–173
173
[16] L. Crociani, G. Bandoli, A. Dolmella, M. Basato, B. Corain,
Eur. J. Inorg. Chem. (1998) 1811.
[17] E.K. van den Beuken, W.J.J. Smeets, A.L. Spek, B.L. Feringa, J.
Chem. Soc., Chem. Commun. (1998) 223.
[18] J.-X. Gao, T. Ikariya, R. Noyoro, Organometallics 15 (1996)
1087.
[19] S. Antonaroli, B. Crociani, J. Organomet. Chem. 560 (1998) 137.
[20] A.G.J. Ligtenbarg, E.K. van den Beuken, A. Meetsma, N.
Veldman, W.J.J. Smeets, A.L. Spek, B.L. Feringa, J. Chem.
Soc., Dalton Trans. (1998) 263.
[21] R.E. Ru¨lke, V.E. Kaasjager, P. Wehman, C.J. Elsevier,
P.W.N.M. van Leeuwen, K. Vrieze, Organometallics 15 (1996)
3022.
[22] W.J. Knebel, R.J. Angelici, Inorg. Chem. 13 (1974) 627.
[23] W.J. Knebel, R.J. Angelici, Inorg. Chem. 13 (1974) 632.
[24] H.C.E. McFarlane, W. McFarlane, A.S. Muir, Polyhedron 9
(1990) 1757.
[25] G.U. Spiegel, O. Stelzer, Chem. Ber. 123 (1990) 989.
[26] G.U. Spiegel, O. Stelzer, Z. Naturforsch., Teil B 42 (1987) 579.
[27] Z.Z. Zhang, H.K. Wang, H.G. Wang, R.J. Wang, J. Organomet.
Chem. 314 (1986) 357.
[28] Z.Z. Zhang, H.K. Wang, Y.J. Shen, H.G. Wang, R.J. Wang, J.
Organomet. Chem. 381 (1990) 45.
found in compounds with the same ligand coordinating
Pd (square-planar) [16], Rh [11] and Ru [46].
The Mo–P and Mo–N distances are similar to those
found in related compounds [47,48]. The mutually trans
,
CO groups bind at an average distance of 2.026(3) A.
The carbonyl ligand trans to P is found at a distance of
,
1.996(3) A while the M–CO bond distance opposite the
,
imine group is 1.947(3) A. The distances follow the
expected trends based on the electronic properties of
their associated trans ligands [43], increasing as the
p-acceptor ability of the ligand trans to the bond in
question increases (N-donorBP-donorBCO).
Acknowledgements
Financial support of this work by the Direccio´n
General de Ensen˜anza Superior e Investigacio´n Cien-
t´ıfica (project PB97-1036), Spain, is acknowledged. J.P.
thanks Cajamurcia for a research grant.
[29] K. Mashima, H. Nakano, T. Mori, H. Takaya, A. Nakamura,
Chem. Lett. (1992) 185.
[30] J.P. Farr, M.M. Olmstead, N.M. Rutherford, F.E. Wood, A.L.
Balch, Organometallics 2 (1983) 1758.
[31] C.G. Arena, F. Faraone, M. Fochi, M. Lafranchi, C. Mealli, R.
Seeber, A. Tiripicchio, J. Chem. Soc., Dalton Trans. (1992) 1847.
[32] S.C.N. Hsu, Wen Yann Yeh, J. Chem. Soc., Dalton Trans.
(1998) 125.
[33] E.W. Ainscough, A.M. Brodie, S.L. Ingham, J.M. Waters, In-
org. Chim. Acta 234 (1995) 163.
[34] P.J. Heard, D.A. Tocher, J. Chem. Soc., Dalton Trans. (1998)
2169.
[35] R. Soltek, G. Huttner, L. Zsolnai, A. Driess, Inorg. Chim. Acta
269 (1998) 143.
[36] D.J. Darensbourg, R.L. Kump, Inorg. Chem. 17 (1978) 2680.
[37] M.A. Beckett, D.P. Cassidy, A.J. Duffin, Inorg. Chim. Acta 189
(1991) 229.
[38] P.K. Baker, A.E. Jenkins, Polyhedron 16 (1997) 129.
[39] P.K. Baker, M. Meehan, J. Organomet. Chem. 535 (1997) 129.
[40] M.J. Alder, W.I. Cross, K.R. Flower, R.G. Pritchard, J.
Organomet. Chem. 568 (1998) 279.
[41] G.M. Sheldrick, SHELXS-97, University of Go¨ttingen, Germany,
1997.
[42] G.M. Sheldrick, SHELXL-97, University of Go¨ttingen, Germany,
1997.
[43] D.J. Darensbourg, Inorg. Chem. 18 (1979) 2821.
[44] G. Sa´nchez, J.L. Serrano, M.A. Moral, J. Pe´rez, E. Molins, G.
Lo´pez, Polyhedron 18 (1999) 3057.
[45] L.J. Todd, J.R. Wilkinson, J. Organomet. Chem. 77 (1974) 1.
[46] P. Bhattacharyya, M.L. Loza, J. Parr, A.M.Z. Slawin, J. Chem.
Soc., Dalton Trans. (1999) 2917.
[47] G.R. Dobson, I. Bernal, G.M. Reisner, C.B. Dobson, S.E.
Mansour, J. Am. Chem. Soc. 107 (1985) 525.
[48] W.-K. Wong, J.-X. Gao, W.-T. Wong, Polyhedron 12 (1993)
1047.
References
[1] J.R. Dilworth, S.D. Howe, A.J. Hutson, J.R. Miller, J. Silver,
R.M. Thomson, M. Harman, M.B. Hursthouse, J. Chem. Soc.,
Dalton Trans. (1994) 3535.
[2] J.R. Dilworth, A.J. Hutson, J.S. Lewis, J.R. Miller, Y. Zheng, Q.
Chen, J. Zubieta, J. Chem. Soc., Dalton Trans. (1995) 1903.
[3] J.R. Dilworth, J.R. Miller, N. Wheatley, M.J. Baker, G. Sunley,
J. Chem. Soc., Chem. Commun. (1995) 1579.
[4] G.P.C.M. Dekker, A. Buijs, C.J. Elsevier, K. Vrieze, P.W.N.M.
van Leeuwen, W.J.J. Smeets, A.L. Spek, Y.F. Wang, C.H. Stam,
Organometallics 11 (1992) 1937.
[5] G.R. Newcome, Chem. Rev. 93 (1993) 2067.
[6] S. Stoccoro, G. Chelucci, A. Zucca, M.A. Cinellu, G. Minghetti,
J. Manassero, J. Chem. Soc., Dalton Trans. (1996) 1295.
[7] D.Ch. Mudalige, E.S. Ma, S.J. Retting, B.R. James, W.R.
Cullen, Inorg. Chem. 36 (1997) 5426.
[8] S. Antonaroli, B. Crociani, J. Organomet. Chem. 560 (1998) 137.
[9] G.M. Kapteijn, M.P.R. Spee, D.M. Grove, H. Kooijman, A.L.
Spek, G. van Koten, Organometallics 15 (1996) 1405.
[10] P. Barbaro, C. Bianchini, F. Laschi, S. Midollini, S. Moneti, G.
Scapacci, P. Zanello, Inorg. Chem. 33 (1994) 1622.
[11] C.A. Ghilardi, S. Midollini, S. Moneti, A. Orlandini, G.
Scapacci, J. Chem. Soc., Dalton Trans. (1992) 3371.
[12] E. Drent, P. Arnoldy, P.H.M. Budzelaar, J. Organomet. Chem.
475 (1994) 57.
[13] H. Brunner, J. Fu¨rst, Inorg. Chim. Acta 220 (1994) 63.
[14] P. Wehman, H.M.A. van Donge, A. Hagos, P.C.J. Kamer,
P.W.N.M. van Leeuwen, J. Organomet. Chem. 535 (1997) 183.
[15] A. Bacchi, M. Carcelli, M. Costa, A. Leporati, E. Leporati, P.
Pelagatti, C. Pelizzi, G. Pelizzi, J. Organomet. Chem. 535 (1997)
107.
.