Approaches to triosmium carbonyl cluster compounds derived from benzophenone imine. Characterization of terminal imino, bridging amido, and orthometalated imino derivatives

Article abstract of DOI:10.1021/om0004139

The cluster complexes [OssHfa-HjfHNCPhz)(CO)id (1), [Os3(u-H)(u-HN-CHPh2)(CO)io] (2), [Os3(uH)(u-HN-CHPh2)(HN=CPh2)(CO)o] (3), and [Os3(uH){HN=CPh(C6H4)}(CO)1(J (4) have been obtained by treatment of [Os3(u-H)2(CO)1(J and I or [Os3(MeCN)2(CO)ioJ with benz

Full text of DOI:10.1021/om0004139

Organometallics 2000, 19, 4643-4646
4643
Ap p r oa ch es to Tr iosm iu m Ca r bon yl Clu ster Com p ou n d s
Der ived fr om Ben zop h en on e Im in e. Ch a r a cter iza tion of
Ter m in a l Im in o, Br id gin g Am id o, a n d Or th om eta la ted
Im in o Der iva tives
J avier A. Cabeza,*,† Ignacio del R´ıo,† Fabrizia Grepioni,*,‡ and V´ıctor Riera†
Departamento de Quı´mica Orga´nica e Inorga´nica, Instituto de Qu´ımica Organometa´lica
“Enrique Moles”, Universidad de Oviedo-CSIC, E-33071 Oviedo, Spain, and
Dipartimento di Chimica, Universita´ di Sassari, Via Vienna 2, I-07100 Sassari, Italy
Received May 15, 2000
Summary: The cluster complexes [Os3H(µ-H)(HNdCPh2)-
(CO)10] (1), [Os3(µ-H)(µ-HN-CHPh2)(CO)10] (2), [Os3(µ-
H)(µ-HN-CHPh2)(HNdCPh2)(CO)9] (3), and [Os3(µ-
H){η2-HNdCPh(C6H4)}(CO)10] (4) have been obtained by
treatment of [Os3(µ-H)2(CO)10] and/ or [Os3(MeCN)2-
(CO)10] with benzophenone imine. These compounds are
unusual examples of metal clusters containing terminal
imino (1, 3), bridging amido (2, 3), and orthometalated
(chelating) imino (4) ligands derived from an N-unsub-
stituted organic imine.
with [Ru3(CO)12] in the presence of carboxylic acids or
molecular hydrogen.8 For osmium, the number of re-
ported compounds of this type is even more limited,
being restricted to [Os3(HNdC6H10)(CO)11] and [Os3-
(µ-H)(µ-NdC5H8)(CO)10], prepared by condensation of
cyclohexanone with [Os3(NH3)(CO)11],9a and to prod-
ucts of reactions of activated nitriles with [Os3(µ-H)2-
(CO)10].9b-d Very recently, when the experimental part
of our work was already finished, the synthesis of imino
complexes of the type [Os3H(µ-H)(HNdCHR)(CO)10] (R
) Me, Ph, CHMe2, 2-furyl) by condensation of aldehydes
with [Os3H(µ-H)(NH3)(CO)10] has been published.10
The interesting derivative chemistry observed for
[Ru3(µ-H)(µ-NdCPh2)(CO)10]1-6 and the absence in the
literature of a related chemistry for osmium prompted
us to attempt the synthesis of an analogous trinuclear
osmium imido cluster. We describe here the reactivity
of [Os3(CO)12], [Os3(µ-H)2(CO)10], and [Os3(MeCN)2-
(CO)10] with benzophenone imine.
In tr od u ction
In a previous work, we reported a high-yield synthesis
of the triruthenium cluster [Ru3(µ-H)(µ-NdCPh2)-
(CO)10],1 a compound that contains a bridging imido (or
1-azavinylidene) ligand derived from benzophenone
imine. Its efficient preparation and its stability under
ambient conditions allowed us to study its reactivity
toward phosphines,1,2 alkynes,3,4 protic acids,2,5 hydro-
gen, silanes, and stannanes.6 These studies afforded,
among other noteworthy results, unprecedented ex-
amples of insertion reactions of nonactivated alkynes
into metal-nitrogen bonds.4
Nowadays, metal cluster complexes containing imino
or imido ligands derived from N-unsubstituted organic
imines are still very rare. As far as we are aware, apart
from [Ru3(µ-H)(µ-NdCPh2)(CO)10] and its derivatives,1-6
these complexes are restricted to a few examples of
metals of the iron triad.7-10 In the case of ruthenium,
the only previously known compounds of this type are
the triruthenium clusters [Ru3(µ-H)(µ-NdCHR)(CO)10],
which were synthesized in low yields by treating nitriles
Resu lts a n d Discu ssion
No reaction was observed between [Os3(CO)12] and
benzophenone imine even after long reaction times (3-5
h) at high temperature (refluxing toluene). In addition,
treatment of this osmium cluster with the lithium salt
of benzophenone imine, followed by titration with tri-
fluoroacetic acid, led to an intractable mixture of
compounds. Curiously, although [Ru3(CO)12] does not
react with benzophenone imine under thermal condi-
tions either,1 it gives [Ru3(µ-H)(µ-NdCPh2)(CO)10] with
good yield when it is sequentially treated with the
lithium salt of benzophenone imine and trifluoroacetic
acid.1 These results led us to try the more reactive
clusters [Os3(µ-H)2(CO)10] and [Os3(MeCN)2(CO)10] as
the starting materials.
† Departamento de Qu´ımica Orga´nica e Inorga´nica (Oviedo). E-
mail: jac@sauron.quimica.uniovi.es. Fax: +34-985103446.
‡ Dipartimento di Chimica (Sassari). E-mail: grepioni@ssmain.
uniss.it. Fax: +39-079212069.
(1) Andreu, P. L.; Cabeza, J . A.; del R´ıo, I.; Riera, V.; Bois, C.
Organometallics 1996, 15, 3004.
(2) Cabeza, J . A.; del R´ıo, I.; Riera, V. J . Organomet. Chem. 1997,
548, 255.
(3) Cabeza, J . A.; del R´ıo, I.; Franco, R. J .; Grepioni, F.; Riera, V.
Organometallics 1997, 16, 2763.
(8) (a) Lausarot, P. M.; Vaglio, G. A.; Valle, M.; Tiripicchio, A.;
Tiripicchio-Camellini, M. J . Chem. Soc., Dalton Trans. 1983, 1391. (b)
Lausarot, P. M.; Turini, M.; Vaglio, G. A.; Valle, M.; Tiripicchio, A.;
Tiripicchio-Camellini, M.; Gariboldi, P. J . Organomet. Chem. 1984, 273,
239. (c) Bernhardt, W.; Vahrenkamp, H. Angew. Chem., Int. Ed. Engl.
1984, 23, 381; Angew. Chem. 1986, 96, 362. (d) Lausarot, P. M.; Operti,
L.; Vaglio, G. A.; Valle, M.; Tiripicchio, A.; Tiripicchio-Camellini, M.;
Gariboldi, P. Inorg. Chim. Acta 1986, 122, 103. (e) Bernhardt, W.;
Vahrenkamp, H. Z. Naturforsch. B 1988, 43, 643.
(4) Cabeza, J . A.; del R´ıo, I.; Moreno, M.; Riera, V.; Grepioni, F.
Organometallics 1998, 17, 3027.
(5) Cabeza, J . A.; del R´ıo, I.; Riera, V.; Ardura, D. J . Organomet.
Chem. 1998, 554, 117.
(6) Bois, C.; Cabeza, J . A.; Franco, R. J .; Riera, V.; Saborit, E. J .
Organomet. Chem. 1998, 564, 201.
(7) For examples of iron derivatives, see: (a) Andrews, M. A.; Kaesz,
H. D. J . Am. Chem. Soc. 1979, 101, 7238. (b) Andrews, M. A.; van
Buskirk, G.; Knobler, C. B.; Kaesz, H. D. J . Am. Chem. Soc. 1979, 101,
7245. (c) Andrews, M. A.; Kaesz, H. D. J . Am. Chem. Soc. 1979, 101,
7255, and references therein.
(9) (a) Su¨ss-Fink, G. Z. Naturforsch. 1980, 35B, 454. (b) Adams, R.
D.; Katahira, D. A.; Yang, L.-W. J . Organomet. Chem. 1981, 219, 85.
(c) Adams, R. D.; Katahira, D. A.; Yang, L.-W. J . Organomet. Chem.
1981, 219, 241. (d) Banford, J .; Dawoodi, Z.; Henrick, K.; Mays, M. J .
J . Chem. Soc., Chem. Commun. 1982, 554.
(10) Aime, S.; Fe´rriz, M.; Gobetto, R.; Valls, E. Organometallics
1999, 18, 2030.
10.1021/om0004139 CCC: $19.00 © 2000 American Chemical Society
Publication on Web 09/29/2000

4644 Organometallics, Vol. 19, No. 22, 2000
Notes
Ch a r t 1
F igu r e 1. Molecular structure of compound 2. Selected
bond lengths (Å): Os(1)-Os(2) 2.798(1), Os(1)-Os(3) 2.846-
(1), Os(2)-Os(3) 2.840(1), Os(1)-N(1) 2.11(1), Os(2)-N(1)
2.10(1), N(1)-C(11) 1.50(1), mean Os-C(CO) 1.91(2), mean
C-O 1.14(2).
The unsaturated precursor [Os3(µ-H)2(CO)10] reacted
smoothly with benzophenone imine in THF at room
temperature to give the trinuclear derivative [Os3H(µ-
H)(HNdCPh2)(CO)10] (1, Chart 1) in quantitative yield.
imine. A 2 h reaction in refluxing THF rendered a mix-
ture from which compound 4 was isolated in 35% yield.
Similar results were obtained carrying out the reaction
at room temperature after longer reaction times (12 h).
The 1H NMR spectrum of 2 shows the hydride
resonance (δ -15.08) and the coupling (J ) 12.4 Hz) of
the N-H (δ 5.42) and C-H (δ 4.11) protons. The
structure proposed for 2 in Chart 1 was confirmed by
an X-ray diffraction study. Figure 1 shows a representa-
tion of this molecule. Relevant bond distances and
angles are given in the figure caption. The compound,
of approximately Cs symmetry, can be described as a
triangle of osmium atoms with an edge doubly bridged
by a hydride ligand and the nitrogen atom of the amido
ligand. The molecule is completed with 10 carbonyl
ligands. Full structural details are given in the Sup-
porting Information. This structure was also suggested
by the pattern of its IR spectrum in the carbonyl
stretching region, which is similar to that of the
ruthenium cluster [Ru3(µ-H)(µ-HN-CHPh2)(CO)10], which
was formed by hydrogenation of [Ru3(µ-H)(µ-NdCPh2)-
(CO)10].6 However, the structure of this ruthenium
amido cluster has never been determined by diffraction
methods.
1
Its H NMR spectrum shows two singlet resonances in
the high-field region, δ -9.91 and -15.84, indicating
the presence of two inequivalent hydride ligands, while
the hydrogen atom of the coordinated imine appears as
a broad singlet at δ 9.93. These data, together with those
obtained from microanalysis, FABMS investigations,
and subsequent reactivity studies (vide infra), strongly
support that complex 1 is isostructural with the com-
plexes [Os3H(µ-H)(HNdCHR)(CO)10], formed by con-
densation of aldehydes with [Os3H(µ-H)(NH3)(CO)10].10
Using NMR methods, it has been proposed that the
imino ligands of these complexes are coordinated in a
terminal mode through the nitrogen atom, being stabi-
lized by an interaction between the N-H hydrogen atom
and the terminal hydride ligand of the molecule.10
Unfortunately, despite many attempts, we could not get
X-ray quality crystals of 1 to confirm this structure
proposal. These data indicate that benzophenone imine
behaves as a ligand in the same way as ammonia11 and
primary and secondary amines12 in its reaction with
[Os3(µ-H)2(CO)10].
1
The H NMR spectrum of complex 3 shows a singlet
Thermolysis of 1 in refluxing 1,2-dichloroethane for
2 h led to a color change of the solution from yellow to
brown. The 1H NMR spectrum of the crude reaction
mixture revealed the presence of [Os3(µ-H)2(CO)10] and
three new products, subsequently identified as [Os3-
(µ-H)(µ-HN-CHPh2)(CO)10] (2), [Os3(µ-H)(µ-HN-CHPh2)-
(HNdCPh2)(CO)9] (3), and [Os3(µ-H){η2-HNdCPh(C6H4)}-
(CO)10] (4) in ca. 2:2:1:1 ratio, respectively (Chart 1).
When free benzophenone imine was added to the
solution of 1 in 1,2-dichloroethane, the thermolysis led
to compounds 2 and 3 in ca. 1:1 ratio, while [Os3(µ-H)2-
(CO)10] and the orthometalated derivative 4 were not
observed in the reaction mixture. All these products
could be separated by chromatographic methods.
In a further attempt to prepare the osmium analogue
of [Ru3(µ-H)(µ-NdCPh2)(CO)10], the labile compound
[Os3(MeCN)2(CO)10] was treated with benzophenone
resonance at δ -13.08, which can be assigned to a
hydride ligand, while the hydrogen atom of the imino
group appears as a broad singlet at δ 9.38. The benzene
solvate compound was characterized by X-ray diffraction
methods. The molecular structure is shown in Figure
2. Relevant bond distances and angles are given in the
figure caption. The structure is similar to that of
compound 2, with an N-coordinated benzophenone
imine replacing a carbonyl ligand in an equatorial
position, cis to both the hydride and the amido ligands.
Full structural details can be found in the Supporting
Information. As far as we are aware, the only previous
examples of clusters containing terminal N-unsubsti-
tuted imino ligands are the triosmium carbonyl clusters
[Os3(HNdC6H10)(CO)11]9a and [Os3H(µ-H)(HNdCHR)-
(CO)10] (R ) Me, Ph, CHMe2, 2-furyl),10 but they have
not been characterized by diffraction methods. In these
complexes, the terminal imino ligand appears to be
stabilized by an intramolecular hydrogen-bonding in-
teraction between the N-H fragment and the terminal
(11) Aime, S.; Dastru´, W.; Gobetto, R.; Arce, A. J . Organometallics
1994, 13, 4232.
(12) Aime, S.; Gobetto, R.; Valls, E. Organometallics 1997, 16, 5140.

Notes
Organometallics, Vol. 19, No. 22, 2000 4645
Information. Orthometalation of benzophenone imine
has previously been observed in mononuclear com-
plexes13 and in one trinuclear Ru cluster.1
Con clu sion s
Four triosmium carbonyl cluster complexes containing
imino and amido ligands derived from an N-unsubsti-
tuted organic imine have been prepared and character-
ized. Among them, compounds 1 and 3 are noteworthy
because they contain a terminal imino ligand, a coor-
dination mode that has been very rarely observed for
N-unsubstituted organic imines.9a,10 Compounds 2 and
3 contain bridging amido ligands which result from a
thermally induced intramolecular hydrogen transfer
process within 1. Orthometalation (C-H bond activa-
tion) is preferred over N-H bond activation when
benzophenone imine is treated with [Os3(MeCN)2-
(CO)10], leading to compound 4. Unfortunately, the
osmium analogue of [Ru3(µ-H)(µ-NdCPh2)(CO10] still
remains unknown.
F igu r e 2. Molecular structure of compound 3. Selected
bond lengths (Å): Os(1)-Os(2) 2.815(1), Os(1)-Os(3) 2.842-
(1), Os(2)-Os(3) 2.852(1), Os(1)-N(1) 2.138(8), Os(2)-N(1)
2.124(7), Os(1)-N(2) 2.162(7), N(1)-C(10) 1.49(1),
N(2)-C(23) 1.28(1), mean Os-C(CO) 1.89(4), mean C-O
1.16(2).
Exp er im en ta l Section
Gen er a l Com m en ts. Solvents were dried over sodium
benzophenone ketyl (THF, hydrocarbons) or CaH2 (dichloro-
methane, 1,2-dichloroethane) and distilled under nitrogen
prior to use. Unless otherwise stated, the reactions were per-
formed under nitrogen at room temperature. [Os3(µ-H)2(CO)10]-
was prepared as described previously.14 All other reagents
were obtained from commercial sources. NMR spectra were
recorded at room temperature with Bruker AC-200 or AC-300
instruments, using SiMe4 as internal standard (δ 0). FABMS
were obtained from the University of Santiago de Compostela
Mass Spectroscopic Service; data given refer to the most
abundant molecular ion isotopomer. Microanalyses were ob-
tained from the University of Oviedo Analytical Service.
Syn th esis of [Os3H(µ-H)(NHdCP h 2)(CO)10] (1). An ex-
cess of benzophenone imine (0.1 mL) was added to a solution
of [Os3(µ-H)2(CO)10] (200 mg, 0.235 mmol) in 20 mL of
dichloromethane. The color changed instantaneously from
violet to pale yellow. After stirring for 10 min, the solvent was
removed under reduced pressure. The residue was washed
with hexanes (1 × 5 mL) to afford compound 1 as a yellow
solid (242 mg, 100%). Calcd for C23H13NO10Os3 (1033.96): C,
26.77; H, 1.27; N, 1.36. Found: C, 26.70; H, 1.30; N, 1.33.
FABMS (m/z): 1035 [M+]. IR (CH2Cl2): ν(CO) 2100 (m), 2061
F igu r e 3. Molecular structure of compound 4. Selected
bond lengths (Å): Os(1)-Os(2) 3.034(3), Os(1)-Os(3) 2.893-
(3), Os(2)-Os(3) 2.902(2), Os(1)-N(1) 2.115(7), Os(1)-C(23)
2.076(9), N(1)-C(11) 1.30(1), mean Os-C(CO) 1.92(4), mean
C-O 1.12(2).
hydride ligand. In the case of complex 3, however, the
X-ray diffraction data clearly show that this type of
interaction is not present, at least in the solid state,
since the hydrogen atom of the coordinated imine is
positioned far away from the bridging hydride ligand.
The 1H NMR spectrum of compound 4 shows a singlet
resonance in the high-field region, at δ -16.58, which
can be assigned to a hydride ligand, while a broad
singlet at δ 9.13 is compatible with the presence of an
N-H group. The spectrum also suggests the orthometa-
lation of a phenyl ring, displaying signals in the range
δ 8.16-7.01. Again, the spectroscopic data were not
enough to unequivocally assign a structure, and an
X-ray diffraction study was carried out. The structure
of 4 is depicted in Figure 3. Relevant bond distances
and angles are given in the figure caption. The structure
consists of an Os3 triangle attached to an orthometa-
lated benzophenone imine ligand. The nitrogen atom of
the imino ligand occupies an axial position, while the
carbon atom of the orthometalated phenyl ring is
attached to the same Os atom in an equatorial position.
The hydride ligand spans the Os(1)-Os(2) bond, in a
position approximately trans to the C(23)-Os(1) bond.
The structure is completed with 10 carbonyl ligands.
Full structural details can be found in the Supporting
(vs), 2048 (vs), 2020 (s), 2001 (s), 1984 (m, sh), 1964 (w) cm-1
.
1H NMR (CD2Cl2): δ 9.93 (s, br, 1 H, NH), 7.67-7.28 (m, 10
H, Ph2), -9.91 (s, 1 H, Os-H), -15.84 (s, 1 H, µ-H) ppm.
Th er m olysis of Com p ou n d 1. Complex 1 (100 mg, 0.097
mmol) was dissolved in 20 mL of 1,2-dichloroethane, and the
mixture was stirred at reflux temperature for 2 h. The color
changed from yellow to brown. The solvent was removed under
reduced pressure to give a brown residue. 1H NMR monitoring
of this residue showed the presence of compounds [Os3(µ-H)2-
(CO)10], 2, 3, and 4 in ca. 2:2:1:1 ratio. The residue was
dissolved in 2 mL of dichloromethane and was transferred to
a silica gel chromatography column (30 × 2 cm). Two bands
(13) See, for example: (a) Werner, H.; Daniel, T.; Braun, T.;
Nu¨rnberg, O. J . Organomet. Chem. 1993, 462, 309. (b) Bohanna, C.;
Esteruelas, M. A.; Lo´pez, A. M.; Oro, L. A. J . Organomet. Chem. 1996,
526, 73. (c) Daniel, T.; Mu¨ller, M.; Werner, H. Inorg. Chem. 1991, 30,
3118. (d) Daniel, T.; Werner, H. Z. Naturforsch. B 1992, 47, 1707. (e)
Daniel, T.; Knaup, M.; Dziallas, M.; Werner, H. Chem. Ber. 1993, 126,
1981. (f) Werner, H.; Daniel, T.; Braun, T.; Nu¨rnberg, O. J . Organomet.
Chem. 1994, 480, 145. (g) Daniel, T.; Werner, H. J . Chem. Soc., Dalton
Trans. 1994, 221. (h) Esteruelas, M. A.; Lahoz, F. J .; Lo´pez, A. M.;
On˜ate, E.; Oro, L. A. Organometallics 1995, 14, 2496. (i) Esteruelas,
M. A.; Gutie´rrez-Puebla, E.; Lo´pez, A. M.; On˜ate, E.; Tolosa J . I.
Organometallics 2000, 19, 275.
(14) Kaesz, H. D. Inorg. Synth. 1990, 28, 238.

4646 Organometallics, Vol. 19, No. 22, 2000
Ta ble 1. Cr ysta l Da ta a n d Deta ils of Mea su r em en ts for Com p ou n d s 2, 3‚C6H6, a n d 4
Notes
2
3‚C6H6
4
formula
fw
cryst syst
space group
a, Å
b, Å
c, Å
C
23H13NO10Os3
C41H30N2O9Os3
1265.27
triclinic
C23H11NO10Os3
1031.93
monoclinic
P21/n
13.00(1)
12.548(7)
16.36(1)
90
108.97(8)
90
2524(3)
4
1033.94
monoclinic
C2/c
23.472(5)
11.120(3)
20.593(6)
90
106.98(2)
90
5151(2)
8
P1h
11.029(1)
12.278(1)
15.922(2)
101.681(4)
106.035(3)
94.080(4)
2010(4)
R, deg
â, deg
γ, deg
V, Å3
Z
2
F(000)
3728
Mo KR (0.71073)
2.672
1180
Mo KR (0.71073)
2.090
1856
Mo KR (0.71073)
2.716
radiation (λ, Å)
Dcalcd, g cm-3
µ(Mo KR), mm-1
min-max transmn
cryst size, mm3
temp, K
14.85
9.51
15.12
0.48-1.00a
0.22 × 0.18 × 0.18
293(2)
0.23-1.00b
0.20 × 0.16 × 0.16
293(2)
0.69-1.00a
0.18 × 0.18 × 0.16
293(2)
θ limits, deg
min/max h, k, l
no. of rflns measd
no. of unique rflns
no. of rflns I > 2σ(I)
no. of params
GOF on F2
R1 (on F, I > 2σ(I))
wR2 (on F2, all data)
3.0-25.0
-27/26, 0/13, 0/24
9763
4465
3680
314
0.985
0.0526
0.1482
1.37-30.00
-15/15, -17/15,-21/22
24 718
11 680
5443
437
0.803
0.0502
0.1141
3.0-25.0
-15/14, 0/14, 0/19
4594
4432
3542
334
1.018
0.0349
0.0931
a
b
ψ-scan absorption correction. Bruker area detector absorption correction.
were eluted using a mixture of hexanes/toluene (5:1) as eluant.
The first band, violet, was subsequently identified as [Os3(µ-
H)2(CO)10] (1H NMR, IR). The second band, yellow, afforded
compound 2 (15 mg, 15%). Further elution with a mixture of
hexanes/dichloromethane (4:1) gave two additional bands. The
third fraction, orange, afforded complex 3 (10 mg, 9%). The
fourth band, pale yellow, contained complex 4 (10 mg, 10%).
chromatography column (20 × 1.5 cm). A mixture of hexanes/
dichloromethane (5:1) was used as eluant. The compound
isolated from the first band, orange, remains unidentified. The
second band, orange, contained compound 4 (40 mg, 35%).
Cr ysta l Str u ctu r e Deter m in a tion of Com p ou n d s 2, 3‚
C6H6, a n d 4. Crystal data and details of measurements are
summarized in Table 1.
Sp ect r oscop ic d a t a for 2: Calcd for
C
23H13NO10Os3
X-ray diffraction data collections were carried out on a
NONIUS CAD-4 diffractometer (compounds 2 and 4) and on
a Bruker area detector diffractometer (compound 3‚C6H6).
Structures were solved by direct methods followed by differ-
ence Fourier syntheses and full-matrix least-squares refine-
ment on F2 using SHELXL97.15a All non-H atoms were treated
anisotropically. Absorption correction for 2 and 4 was applied
by azimuthal scanning of high ø reflections. H atoms bound
to N and C atoms were added in calculated positions and
refined riding on their respective N and C atoms. The positions
of the hydride atoms were estimated using the program
XHYDEX;15b their coordinates were included in the Fourier
calculations but not refined. The approximate location of the
H(hydride) atoms was also detectable by visual inspection of
space-filling plots of the three molecules: suitable niches were
invariably found corresponding to the calculated positions. The
program SCHAKAL9715c was used for all graphical represen-
tations.
(1033.94): C, 26.72; H, 1.27; N, 1.35. Found: C, 26.85; H, 1.11;
N, 1.28. FABMS (m/z): 1035 [M+]. IR (CH2Cl2): ν(CO) 2103
(w), 2067 (vs), 2050 (s), 2017 (s), 1999 (m), 1988 (m), 1975 (w,
1
sh) cm-1. H NMR (CD2Cl2): δ 7.40-7.17 (m, 10 H, Ph2), 5.42
(d, br, J ) 12.4 Hz, 1 H NH), 4.11 (d, J ) 12.4 Hz, 1 H CH),
-15.08 (s, 1 H, µ-H) ppm.
Sp ectr oscop ic d a ta for 3: Anal. Calcd for C35H24N2O9-
Os3 (1187.19): C, 35.46; H, 2.04; N, 2.36. Found: C, 35.71; H,
1.90; N, 2.30. FABMS (m/z): 1188 [M+]. IR (CH2Cl2): ν(CO)
2121 (w), 2085 (m), 2046 (vs), 2005 (s), 1992 (s), 1966 (m), 1923
(w) cm-1 1H NMR (CD2Cl2): δ 9.38 (s, br, 1 H, NH), 7.59-
.
7.00 (m, 20 H, Ph4), 5.35 (d, br, J ) 12.8 Hz, 1 H NH), 4.15 (d,
J ) 12.8 Hz, 1 H CH), -13.08 (s, 1 H, µ-H) ppm.
Sp ectr oscop ic d a ta for 4: Anal. Calcd for C23H11NO10
-
Os3 (1031.93): C, 26.77; H, 1.07; N, 1.36. Found: C, 26.86; H,
1.10; N, 1.37. FABMS (m/z): 1033 [M+]. IR (CH2Cl2): ν(CO)
2124 (w), 2064 (m), 2050 (m), 2035 (vs), 2023 (m, sh), 1992
1
(s), 1984 (m, sh), 1917 (w) cm-1. H NMR (CDCl3): δ 9.13 (s,
Ack n ow led gm en t. This work was supported by the
Spanish DGES (Grants no. PB95-1042 and PB98-1555)
and the Italian MURST.
br, 1 H, NH), 8.16 (d, J ) 7.6 Hz, 1 H), 7.65-7.51 (m, 6 H),
7.25 (t, J ) 7.6 Hz, 1 H), 7.01 (t, J ) 7.6 Hz, 1 H), -16.58 (s,
1 H, µ-H) ppm.
Rea ction of [Os3(MeCN)2(CO)10] w ith HNdCP h 2. An-
hydrous Me3NO (19 mg, 0.254 mmol) was added to a suspen-
sion of [Os3(CO)12] (100 mg, 0.110 mmol) in 60 mL of aceto-
nitrile over a period of 2 h. The resulting solution was stirred
for a further 1 h, and the solvent was removed under reduced
pressure. The residue was dissolved in 30 mL of THF. Benzo-
phenone imine (28 µL, 0.165 mmol) was added, and the solu-
tion was heated at reflux temperature for 2 h. The solvent was
then removed under reduced pressure to give an orange resi-
Su p p or tin g In for m a tion Ava ila ble: ORTEP drawings,
tables of atomic coordinates, bond distances and angles,
anisotropic thermal parameters, and H atom coordinates for
2-4. This material is available free of charge via the Internet
at http://pubs.acs.org.
OM0004139
(15) (a) Sheldrick, G. M. SHELXL97, Program for Crystal Structure
Determination; University of Go¨ttingen: Go¨ttingen, Germany, 1997.
(b) Orpen, A. G. XHYDEX, A Program for Locating Hydrides; Bristol
University: Bristol, UK, 1980. (c) Keller, E. SCHAKAL97, Graphical
Representation of Molecular Models; University of Freiburg: Freiburg,
Germany, 1997.
1
due. The H NMR spectrum of this residue showed the pres-
ence of compound 4, together with some minor unidentified
impurities. The solid residue was dissolved in 2 mL of dichloro-
methane, and the solution was transferred to a silica gel