Triruthenium, hexaruthenium, and triosmium carbonyl derivatives of 2-amino-6-phenylpyridine

Article abstract of DOI:10.1021/om034040y

The triruthenium cluster complexes [Ru₃(μ-H) (μ₃-η²-HapyPh-N,N)(CO)₉ ] (1) and [Ru₃(μ-H)₂(μ₃-η³- HapyC₆H₄-N,N,C)₂(CO)₆] (2) and the hexaruthenium ones [Ru₆(μ₃-H)₂ (μ₅-η²-apyPh-N,N)(μ-CO)₂ (CO)₁₄] (3) and [Ru₆(μ₃-H) (μ₅-η³-apyC ₆H₄-N,N,C) (μ-CO)₃ (CO)₁₃] (4) have been prepared from [Ru₃(CO)₁₂] and 2-amino-6-phenylpyridine (H₂apyPh). Compound 1 contains a deprotonated HapyPh ligand capping a face of the metal triangle. Compound 2 contains two cyclometalated HapyC₆H₄ ligands, each spanning a Ru-Ru edge through the N atom of the amido fragment and chelating the remaining Ru atom through both the pyridine N atom and the C atom of the cyclometalated ring. The hexanuclear derivatives 3 and 4 have an uncommon basal edge-bridged square pyramidal metallic skeleton. The bridging ligand of 3 is a doubly deprotonated apyPh ligand which caps the metallic square through the exocyclic N atom, while is attached to the Ru atom that bridges the edge of the square pyramid through the pyridine N atom. Complex 4 is structurally related to 3 but has a cyclometalated phenyl ring. It has been established that compound 2 is formed by reaction of 1 with H₂apyPh and that complex 3 is formed by reaction of 1 with [Ru₃(CO)₁₂]. While the hydrogenation of 4 gives 3, the thermolysis of 3 gives 4 among other unidentified products. The reaction of the osmium cluster [Os₃(CO)₁₀ (MeCN)₂] with H₂apyPh gives a 1:5 mixture of the edge-bridged decacarbonyl derivatives [Os₃(μ-H)(μ- η¹-HapyPh-N)(CO)₁₀] (5) and [Os₃(μ-H) (μ-η²-HapyPh-N,N)(CO)₁₀] (6). Both compounds give the face-capped nonacarbonyl derivative [Os₃(μ-H)- (μ₃-η²-HapyPh-N,N) (CO)₉] (7) upon irradiation with UV light. Curiously, while complexes 5 and 7 are stable in refluxing toluene, the thermolysis of 6 gives a mixture of 5, 7, and the cyclometalated dihydride [Os₃(μ-H)₂(μ- η³-HapyC₆H₄-N,N,C)(CO)₉] (8).

Full text of DOI:10.1021/om034040y

Organometallics 2004, 23, 1107-1115
1107
Tr ir u th en iu m , Hexa r u th en iu m , a n d Tr iosm iu m Ca r bon yl
Der iva tives of 2-Am in o-6-p h en ylp yr id in e†
J avier A. Cabeza,* Ignacio del R´ıo, V´ıctor Riera, and Marta Sua´rez
Departamento de Qu´ımica Orga´nica e Inorga´nica, Instituto de Quı´mica Organometa´lica
“Enrique Moles”, Universidad de Oviedo-CSIC, E-33071 Oviedo, Spain
Santiago Garc´ıa-Granda
Departamento de Qu´ımica Fı´sica y Anal´ıtica, Universidad de Oviedo,E-33071 Oviedo, Spain
Received J uly 15, 2003
The triruthenium cluster complexes [Ru3(µ-H)(µ3-η2-HapyPh-N,N)(CO)9] (1) and [Ru3(µ-
Η)2(µ3-η3-HapyC6H4-N,N,C)2(CO)6] (2) and the hexaruthenium ones [Ru6(µ3-H)2(µ5-η2-apyPh-
N,N)(µ-CO)2(CO)14] (3) and [Ru6(µ3-H)(µ5-η3-apyC6H4-N,N,C)(µ-CO)3(CO)13] (4) have been
prepared from [Ru3(CO)12] and 2-amino-6-phenylpyridine (H2apyPh). Compound 1 contains
a deprotonated HapyPh ligand capping a face of the metal triangle. Compound 2 contains
two cyclometalated HapyC6H4 ligands, each spanning a Ru-Ru edge through the N atom of
the amido fragment and chelating the remaining Ru atom through both the pyridine N atom
and the C atom of the cyclometalated ring. The hexanuclear derivatives 3 and 4 have an
uncommon basal edge-bridged square pyramidal metallic skeleton. The bridging ligand of 3
is a doubly deprotonated apyPh ligand which caps the metallic square through the exocyclic
N atom, while is attached to the Ru atom that bridges the edge of the square pyramid through
the pyridine N atom. Complex 4 is structurally related to 3 but has a cyclometalated phenyl
ring. It has been established that compound 2 is formed by reaction of 1 with H2apyPh and
that complex 3 is formed by reaction of 1 with [Ru3(CO)12]. While the hydrogenation of 4
gives 3, the thermolysis of 3 gives 4 among other unidentified products. The reaction of the
osmium cluster [Os3(CO)10(MeCN)2] with H2apyPh gives a 1:5 mixture of the edge-bridged
decacarbonyl derivatives [Os3(µ-Η)(µ-η1-HapyPh-N)(CO)10] (5) and [Os3(µ-H)(µ-η2-HapyPh-
N,N)(CO)10] (6). Both compounds give the face-capped nonacarbonyl derivative [Os3(µ-H)-
(µ3-η2-HapyPh-N,N)(CO)9] (7) upon irradiation with UV light. Curiously, while complexes 5
and 7 are stable in refluxing toluene, the thermolysis of 6 gives a mixture of 5, 7, and the
cyclometalated dihydride [Os3(µ-H)2(µ-η3-HapyC6H4-N,N,C)(CO)9] (8).
In tr od u ction
a hydride ligand, e.g., [Ru3(µ-Η)(µ3-η2-Hapy-N,N)(CO)9]
(Chart 1). Some of these complexes have been recognized
as catalytic precursors for the hydrogenation,3,4 dimer-
ization,5 polymerization,5 and hydroformylation6 of se-
lected alkynes.
We have previously carried out a thorough study of
the synthesis and reactivity of carbonyl metal clusters
derived from 2-aminopyridines.1,2 Most of these clusters
are trinuclear and contain a face-capping apy ligand (H2-
apy ) a generic 2-aminopyridine) that results from the
coordination of the pyridine N atom and the activation
of an N-H bond to give a bridging amido fragment and
In a recent article, we have reported the reactivity of
a particular member of the 2-aminopyridine family,
2-amino-7,8-benzoquinoline (H2abqH), with triruthen-
ium and triosmium carbonyls.7 In ruthenium complexes,
the coordination of the quinoline N atom triggers the
cyclometalation of the benzo ring, e.g., [Ru3(µ3-η3-Habq-
N,N,C)(CO)9] (Chart 1). However, for osmium, the benzo
ring in the 7,8-position hampers the coordination of the
quinoline N atom and only a simple µ-amido derivative
was obtained, [Os3(µ-H)(µ-η1-HabqH-N)(CO)10] (Chart
† Dedicated to Prof. J ose´ Vicente, on the occasion of his 60th
birthday.
* Corresponding author. Fax: int + 34-985103446. E-mail: jac@
sauron.quimica.uniovi.es. Internet: http://www12.uniovi.es/investiga-
cion/jac/.
(1) For a recent review on the reactivity of triruthenium carbonyl
clusters derived from 2-aminopyridines, see: Cabeza, J . A. Eur. J .
Inorg. Chem. 2002, 1559.
(2) For relevant articles in the field, see: (a) Cabeza, J . A.; del R´ıo,
I.; Garc´ıa-Granda, S.; Riera, V.; Sua´rez, M. Organometallics 2002, 21,
2540. (b) Cabeza, J . A.; del R´ıo, I.; Garc´ıa-Granda, S.; Lavigne, G.;
Lugan, N.; Moreno, M.; Nombel, P.; Pe´rez-Priede, M.; Riera, V.;
Rodr´ıguez, A.; Sua´rez, M.; van der Maelen, J . F. Chem. Eur. J . 2001,
7, 2370. (c) Cabeza, J . A.; Riera, V.; Trivedi, R.; Grepioni, F. Organo-
metallics 2000, 19, 2043. (d) Cabeza, J . A.; del R´ıo, I.; Riera, V.; Garc´ıa-
Granda, S.; Sanni, S. B. Organometallics 1997, 16, 1743. (e) Cabeza,
J . A.; Garc´ıa-Granda, S.; Llamazares, A.; Riera, V.; van der Maelen,
J . F. Organometallics 1993, 12, 2973. (f) Andreu, P. L.; Cabeza, J . A.;
Pellinghelli, M. A.; Riera, V.; Tiripicchio, A. Inorg. Chem. 1991, 30,
4611.
(3) Cabeza, J . A. In Metal Clusters in Chemistry; Braunstein, P.,
Oro, L. A., Raithby P. R., Eds.; Wiley-VCH: Weinheim, 1999; p 715.
(4) For a review on alkyne hydrogenation mediated by 2-amidopy-
ridine-bridged triruthenium carbonyl cluster complexes, see: Cabeza,
J . A.; Ferna´ndez-Colinas, J . M.; Llamazares, A. Synlett 1995, 579.
(5) Nombel, P.; Lugan, N.; Mulla, F.; Lavigne, G. Organometallics
1994, 13, 4673.
(6) Nombel, P.; Lugan, N.; Donnadieu, B.; Lavigne, G. Organome-
tallics 1999, 18, 187.
(7) Cabeza, J . A.; del R´ıo, I.; Garc´ıa-Granda, S.; Riera, V.; Sua´rez,
M. Organometallics 2002, 21, 5055.
10.1021/om034040y CCC: $27.50 © 2004 American Chemical Society
Publication on Web 01/27/2004

1108 Organometallics, Vol. 23, No. 5, 2004
Cabeza et al.
Ch a r t 1
Sch em e 1. New P r od u cts Isola ted fr om th e
Rea ction of [Ru 3(CO)12] w ith H2a p yP h a
1). The cyclometalation of H2abqH has also been ob-
served in mononuclear iridium complexes.8
These results prompted us to study the reactivity of
triruthenium and triosmium carbonyls with 2-amino-
6-phenylpyridine (H2apyPh, Chart 1). We were inter-
ested in knowing whether this ligand might present the
same behavior as H2abqH or behave as a “normal”
2-aminopyridine. In addition, as far as we are aware,
no transition metal complexes derived from this ligand
have hitherto been reported.
We now report that both cyclometalated and non-
cyclometalated products have been obtained from the
reactions of H2apyPh with triruthenium and triosmium
carbonyl clusters. Interestingly, these reactions have led
not only to trinuclear products but also to hexaruthen-
ium derivatives of an uncommon metallic skeleton,
basal edge-bridged square pyramid.9
a
Yields depend on the ratio of the reactants, reaction
temperature, and reaction time.
refluxing toluene, whereas the highest yields of the
hexanuclear derivatives 3 and 4 were obtained in
refluxing xylene, using a H2apyPh to [Ru3(CO)12] ratio
of 0.5 and adding the H2apyPh in two portions, to
minimize the formation of complex 2 and [Ru4(µ-Η)4-
(CO)12].
Additional experiments were carried out with the
purpose of establishing relationships between these
products. Complex 1 reacted with [Ru3(CO)12] (1:1 ratio)
to give the hexanuclear derivatives 3 and 4, as well as
some 2 and [Ru4(µ-Η)4(CO)12]. Complex 1 also reacted
with H2apyPh to give 2 quantitatively. This indicates
that in the reactions where [Ru4(µ-Η)4(CO)12] is ob-
served, this complex is formed from [Ru3(CO)12] and the
dihydrogen that should be released when 1 reacts with
H2apyPh to give 2. In addition, it was ascertained that
complex 1 is thermally unstable, since it underwent
decomposition into a mixture of products that contained
complex 2 when its solutions were heated at tempera-
tures higher than 70 °C.
These latter experiments explain why compound 1
was always a minor product in the reactions of [Ru3-
(CO)12] with H2apyPh. Even using a 1:1 [Ru3(CO)12] to
H2apyPh ratio, the yield of 1 was never higher than
15%. With the aim to obtain compound 1 in higher yield,
the activated complex [Ru3(CO)10(MeCN)2] was treated
with H2apyPh (1:1 ratio) in THF. Unfortunately, the
reaction was very slow. After 2 h at room temperature,
most of the [Ru3(CO)10(MeCN)2] decomposed into [Ru3-
(CO)12] and only a 15% yield of compound 1 was
obtained.
The thermolysis of the hexanuclear complex 3 in
refluxing xylene gave a small amount of the cyclometa-
lated derivative 4 and two unidentified products, of
which at least one seemed to contain coordinated xylene
(NMR), but it could not be characterized. To avoid the
interference of xylene, the thermolysis was also carried
out in diglime (140 °C, 3 h). In this case, the products
Resu lts
Syn th esis of H2a p yP h . This compound10 was pre-
pared in 35% yield by amination of 2-phenylpyridine
with sodium amide, following the method previously
described for the synthesis of 2-amino-7,8-benzoquino-
line,8c but using 2-phenylpyridine instead of 7,8-benzo-
quinoline.
Syn th esis of Com p ou n d s 1-4. The reactions of
[Ru3(CO)12] with H2apyPh led to mixtures of the tri-
nuclear complexes [Ru3(µ-H)(µ3-η2-HapyPh-N,N)(CO)9]
(1) and [Ru3(µ-Η)2(µ3-η3-HapyC6H4-N,N,C)2(CO)6] (2)
and the hexanuclear ones [Ru6(µ3-H)2(µ5-η2-apyPh-N,N)-
(µ-CO)2(CO)14] (3) and [Ru6(µ3-H)(µ5-η3-apyC6H4-N,N,C)-
(µ-CO)3(CO)13] (4) (Scheme 1). The yield of each product
depended on the ratio of the reactants and the reaction
conditions. Thus, at H2apyPh to [Ru3(CO)12] ratios
greater than 1, complex 2 was the major product in
(8) (a) Patel, B. P.; Crabtree, R. H. J . Am. Chem. Soc. 1996, 118,
13105. (b) Lee, D.-H.; Patel, B. P.; Clot, E.; Eisenstein, O.; Crabtree,
R. H. Chem. Commun. 1999, 297. (c) Lee, D.-H.; Kwon, H. J .; Patel,
B. P.; Liable-Sands, L. M.; Rheingold, A. L.; Crabtree, R. H. Organo-
metallics 1999, 18, 1615. (d) Gruet, K.; Crabtree, R. H.; Lee, D.-H.;
Liable-Sands, L. M.; Rheingold, A. L. Organometallics 2000, 19, 2228.
(9) The synthesis of the hexaruthenium derivatives has been briefly
communicated in a preliminary form: Cabeza, J . A.; del R´ıo, I.; Garc´ıa-
AÄ lvarez, P.; Riera, V.; Sua´rez, M.; Garc´ıa-Granda, S. Dalton Trans.
2003, 2808.
(10) Goshaev, M.; Otroshchenko, O. S.; Sadykov, A. S.; Azimova, M.
P. Khim. Geterotsikl. Soedin. 1972, 12, 1642; Chem. Abstr. 1973, 78,
58201t.

Tri- and Hexaruthenium Carbonyl Derivatives
Organometallics, Vol. 23, No. 5, 2004 1109
were 3, 4, and one of the unidentified complexes
observed in the thermolysis in xylene, in a ratio of 1:0.5:
0.8, respectively.
The hexanuclear cyclometalated complex 4 observed
in the reactions of [Ru3(CO)12] with H2apyPh seems to
arise from more than one source, since in these reac-
tions, complex 4 is formed after short reaction times,
in yields only a bit lower than those of 3. In addition,
the thermal transformation of 3 into 4 is rather inef-
ficient, even after long reaction times (see above).
Therefore, complex 4 may also be formed by condensa-
tion of [Ru3(CO)12] with a trinuclear cyclometalated
species that would arise from complex 1 under the
reaction conditions. Although such a cyclometalated
species (that would contain either none or two hydride
ligands) has not been detected, an orthometalated
monohydride species was spectroscopically detected
(NMR) as the major product of the thermolysis of
compound 1 in 1,2-dichloroethane. Unfortunately, this
species has not been fully characterized because it could
not be isolated as a pure product (it decomposed on
chromatographic supports). Most probably, the original
orthometalated intermediate evolves to the observed
monohydride species under the reaction conditions.
In addition, although it is clear that, in the reactions
of [Ru3(CO)12] with H2apyPh, most of the hexanuclear
complex 3 is formed by condensation of compound 1 with
[Ru3(CO)12] (this has been checked by condensing [Ru3-
(CO)12] with trinuclear complexes analogous to 1 but
derived from 2-aminopyridines without phenyl substit-
uents9), a small amount of 3 can also arise from the
hydrogenation of the cyclometalated complex 4, since
we checked that this reaction does take place and the
release of hydrogen parallels the formation of com-
pounds 2 and 4. This argument also agrees with the
proposal that, in the reactions of [Ru3(CO)12] with H2-
apyPh, complex 4 does not arise from complex 3.
Ch a r a cter iza tion of Com p ou n d s 1-4. The com-
position and trinuclear nature of 1 was suggested by
its microanalysis and mass spectrum. The presence of
F igu r e 1. Molecular structure of compound 3. Thermal
ellipsoids are drawn at the 50% probability level. Both C
and O atoms of the same carbonyl ligand bear the same
number.
1
NH and hydride groups was indicated by its H NMR
spectrum, which contains singlets at 4.68 and -11.25
ppm, respectively. DEPT 13C NMR spectra show five
CO, six CH, and three C resonances, confirming the Cs
symmetry of the compound. Its IR and NMR spectra
are related to those of other µ3-apy-bridged hydride
nonacarbonyl triruthenium complexes.11
F igu r e 2. Molecular structure of compound 4. Thermal
ellipsoids are drawn at the 40% probability level. Both C
and O atoms of the same carbonyl ligand bear the same
number.
Although the microanalysis and mass spectrum of
compound 2 indicated the presence of two HapyC6H4
1 and 2). As far as possible, a common atomic number-
ing scheme was used for both compounds to facilitate
comparisons between related structural parameters
(Table 1). Both compounds have a basal edge-bridged
square pyramidal metallic skeleton (88 valence elec-
trons). While the pyridine nitrogen N(2) of the bridging
ligand is attached to the metal atom that spans the base
of the square pyramid, Ru(3), the exocyclic nitrogen
atom N(1), which now bears no hydrogen atoms, caps
the metallic square, being ca. 0.06 Å closer to the metal
atoms of the bridged edge, Ru(1) and Ru(2), than to Ru-
(4) and Ru(5). The Ru-Ru distances between the apex
metal atom Ru(6) and the four basal ruthenium atoms
are 0.1-0.2 Å longer than the remaining Ru-Ru
distances. While the phenyl ring of 3 is uncoordinated
and perpendicular to the pyridine plane, that of complex
4 is cyclometalated and coplanar with the pyridine ring,
1
ligands per Ru3 unit, its H and DEPT 13C NMR spectra
display only the resonances of one hydride, one meta-
lated HapyC6H4 ligand, and three CO groups. The CO
region of its IR spectrum is also very simple, showing
three ν(CO) absorptions. The structure depicted for this
complex in Scheme 1 is based on a comparison of its
spectroscopic data with those of the 50-electron complex
[Ru3(µ-H)2(µ3-η3-Habq-N,N,C)2(CO)6], which was char-
acterized by X-ray diffraction methods and has C2
symmetry (the 2-fold axis passes through the central
Ru atom).7
The structures of compounds 3 and 4 in solid state
were determined by X-ray diffraction methods (Figures
(11) Andreu, P. L.; Cabeza, J . A.; Riera, V.; J eannin, Y.; Miguel, D.
J . Chem. Soc., Dalton Trans. 1990, 2201.

1110 Organometallics, Vol. 23, No. 5, 2004
Cabeza et al.
Ta ble 1. Selected In ter a tom ic Dista n ces (Å) in
Com p ou n d s 3 a n d 4
3
4
Ru(1)-Ru(2)
Ru(1)-Ru(3)
Ru(1)-Ru(4)
Ru(1)-Ru(6)
Ru(2)-Ru(3)
Ru(2)-Ru(5)
Ru(2)-Ru(6)
Ru(4)-Ru(5)
Ru(4)-Ru(6)
Ru(5)-Ru(6)
Ru(1)-N(1)
2.7724(5)
2.7763(5)
2.7513(5)
2.9791(6)
2.6841(6)
2.7648(5)
2.8761(5)
2.7381(5)
2.8470(5)
2.9307(5)
2.166(4)
2.164(4)
2.226(4)
2.253(4)
2.222(4)
2.104(5)
1.895(6)
1.895(5)
1.862(5)
1.859(5)
2.7713(9)
2.7532(9)
2.7334(9)
2.9059(9)
2.9018(8)
2.7176(9)
2.9035(9)
2.7300(9)
2.8431(9)
2.8558(9)
2.168(7)
2.139(7)
2.121(7)
2.225(7)
2.215(7)
2.080(10)
1.900(9)
1.889(10)
1.895(9)
1.886(10)
2.010(9)
1.855(10)
1.884(9)
F igu r e 3. Carbonyl region of 13C{1H} NMR spectra (CD2-
Cl2, 75 MHz) of a 13CO-enriched sample of compound 3 at
two different temperatures.
Ru(2)-N(1)
Ru(3)-N(2)
Ru(4)-N(1)
Ru(5)-N(1)
Ru(1)-C(100)
Ru(1)-C(101)
Ru(1)-C(102)
Ru(2)-C(201)
Ru(2)-C(202)
Ru(2)-C(500)
Ru(3)-C(301)
Ru(3)-C(302)
Ru(3)-C(303)
Ru(4)-C(100)
Ru(4)-C(400)
Ru(4)-C(401)
Ru(4)-C(402)
Ru(5)-C(400)
Ru(5)-C(500)
Ru(5)-C(501)
Ru(5)-C(502)
Ru(6)-C(601)
Ru(6)-C(602)
Ru(6)-C(603)
Ru(3)-C(7)
1.906(5)
1.883(6)
1.953(6)
2.064(5)
2.183(5)
1.992(6)
1.882(5)
2.008(5)
2.083(9)
2.107(9)
1.946(9)
1.883(9)
2.048(9)
2.207(10)
1.910(10)
1.895(9)
1.914(11)
1.920(11)
1.885(10)
2.078(8)
F igu r e 4. Carbonyl region of 13C{1H} NMR spectra (CD2-
Cl2, 75 MHz) of a 13CO-enriched sample of compound 4 at
two different temperatures.
1.886(5)
1.880(6)
1.897(6)
1.952(6)
1.896(6)
Sch em e 2
being attached to Ru(3) through C(7). Such an interac-
tion induces a lengthening of the Ru(2)-Ru(3) distance
from 2.6841(6) Å in 3 to 2.9018(8) Å in 4, as a
consequence of the higher trans influence of the phenyl
group with respect to that of the carbonyl ligand. While
both compounds have a hydride ligand capping the Ru-
(1)-Ru(2)-Ru(6) face, complex 3 has an additional
hydride capping the Ru(2)-Ru(5)-Ru(6) face. Both
compounds contain 16 CO ligands, but they differ in the
number of bridging carbonyls, since 3 has two, whereas
4 has three bridging CO ligands. In both cases, these
carbonyl ligands span the edges of the metallic square
that are not bridged by hydride ligands. The structure
of 3 is comparable with that reported for [Ru6(µ3-H)2-
(µ5-η2-NCO2Me-N,O)(µ-CO)2(CO)14], in which the N
atom caps the metallic square and the carbonyl oxygen
atom is attached to the Ru atom that bridges the base
of the square pyramid.12
1
The IR and H NMR spectra of compounds 3 and 4
are in agreement with their solid-state structures. Thus,
the absorptions of two and three bridging CO ligands
are clearly observed in the IR spectra of 3 and 4,
respectively. In their 1H NMR spectra, the hydride
ligands of 3 are observed as two doublets at -11.46 and
-15.87 ppm (J ) 2.4 Hz), whereas that of 4 appears as
a singlet at -16.62 ppm. The 13C NMR spectra of 13CO-
enriched samples of these compounds indicate that their
CO ligands are fluxional at room temperature (Figures
3 and 4). At -80 °C, compound 3 is rigid (the peak at
199.1 ppm contains two coincident resonances). How-
ever, fluxional processes are still active in compound 4
at -80 °C.
Syn th esis of Com p ou n d s 5-8. H2apyPh reacted
with [Os3(CO)10(MeCN)2] in THF at room temperature
to give a 1:5 mixture of the edge-bridged decacarbonyl
derivatives [Os3(µ-H)(µ-η1-HapyPh-N)(CO)10] (5) and
[Os3(µ-H)(µ-η2-HapyPh-N,N)(CO)10] (6), respectively
(Scheme 2). Both compounds underwent decarbonyla-
tion upon irradiation with UV light to give the face-
capped nonacarbonyl derivative [Os3(µ-H)(µ3-η2-HapyPh-
N,N)(CO)9] (7) in quantitative yield (Scheme 2).
(12) Lee, K. K. H.; Wong, W. T. J . Chem. Soc., Dalton Trans. 1996,
1707.

Tri- and Hexaruthenium Carbonyl Derivatives
Organometallics, Vol. 23, No. 5, 2004 1111
Sch em e 3
All attempts to transform these complexes into de-
rivatives analogous to the ruthenium complexes 2-4,
described above, were unsuccessful.
Attempts were also made to transform compounds
5-7 into cyclometalated derivatives via thermal activa-
tion. While complexes 5 and 7 remained unaltered when
they were heated in refluxing toluene for 5 h, complex
6 gave a 2:1:4 mixture of 5, 7, and the cyclometalated
derivative [Os3(µ-H)2(µ-η3-HapyC6H4-N,N,C)(CO)9] (8),
respectively, after a short thermolysis (25 min) in
refluxing toluene (Scheme 3).
Attempting the crystallization of complex 8 by slow
diffusion of pentane into a solution of the complex in
dichloromethane, we always obtained crystals of com-
pound 7 after several days at room temperature. We
subsequently checked that complex 8 undergoes a slow
isomerization into complex 7 under visible light.
F igu r e 5. Molecular structure of compound 7. Thermal
ellipsoids are drawn at the 40% probability level. Both C
and O atoms of the same carbonyl ligand bear the same
number.
Ta ble 2. Selected In ter a tom ic Dista n ces (Å) in
Com p ou n d 7
Os(1)-Os(2)
Os(2)-Os(3)
Os(2)-N(1)
Os(1)-C(101)
Os(1)-C(103)
Os(2)-C(202)
Os(3)-C(301)
Os(3)-C(303)
2.8141(6)
2.7765(6)
2.148(8)
1.96(1)
1.89(1)
1.91(1)
Os(1)-Os(3)
Os(1)-N(1)
2.7873(6)
2.138(9)
2.219(8)
1.90(1)
1.93(1)
1.91(1)
Os(3)-N(2)
Os(1)-C(102)
Os(2)-C(201)
Os(2)-C(203)
Os(3)-C(302)
Ch a r a cter iza tion of Com p ou n d s 5-8. The os-
mium clusters 5 and 6 were characterized by analytical
and spectroscopic methods. Their microanalyses and
mass spectra confirmed their trinuclear nature and the
presence of a HapyPh ligand and 10 CO groups. The
presence of NH and hydride groups was indicated by
1.93(1)
1.88(1)
1.93(1)
The solid-state structure of 7 was determined by
X-ray diffraction methods (Figure 5, Table 2). The
compound has Cs symmetry, with the 2-amidopyridine
ligand capping the metal triangle and the hydride
spanning the same Os-Os edge as the amido fragment.
The phenyl ring is perpendicular to the pyridine plane.
Overall, this structure is similar to those of analogous
triosmium complexes derived from 2-aminopyridine,14
di(2-pyridyl)amine,2a and 7-azaindole,15 which also have
related spectroscopic data in solution.
Compound 8 was characterized by analytical and
spectroscopic methods. Their microanalyses and mass
spectra confirmed its trinuclear nature, the presence of
all the atoms of H2apyPh, and nine CO groups. One NH
and two hydride groups are observed in its 1H NMR
spectrum, which contains signals at 4.35, -13.02, and
-13.32 ppm, respectively. Its DEPT 13C NMR spectra
show seven CH and four C resonances for the bridging
ligand, indicating cyclometalation. Its asymmetry was
confirmed by its 13C NMR spectrum, which shows nine
carbonyl resonances. These data strongly support the
structure proposed for this complex in Scheme 3.
1
their H NMR spectra, which contain signals at 5.94 and
-14.03 ppm, respectively, for 5, and at 4.52 and -11.82
ppm, respectively, for 6. Their DEPT 13C NMR spectra
show eight CH and three C resonances for the bridging
ligand, indicating that it is not metalated. Five lines,
corresponding to six carbonyl resonances, with intensi-
ties 1:1:2:2:4 (the latter contains two overlapping reson-
ances) are also observed in the 13C NMR spectrum of 5,
confirming a Cs symmetry for the complex. The asym-
metry of 6 was indicated by its 13C NMR spectrum,
which shows 10 carbonyl resonances.
All these data are in agreement with the structures
depicted in Scheme 2 for these complexes. For complex
5, although an endo arrangement of the pendant 6-phen-
ylpyrid-2-yl fragment would also be compatible with the
analytical and spectroscopic data, the exo arrangement
minimizes any steric interaction between the organic
fragment and the axial carbonyl ligand on the unbridged
Os atom. This structure is related to those of other
amido-bridged decacarbonyl triosmium complexes,13
including a derivative of H2abqH (Chart 1),7 but none
of these amido ligands arise from 2-aminopyridines. On
the contrary, the structure of compound 6 has been
previously found for triosmium complexes derived from
2-aminopyridine,14 di-(2-pyridyl)amine,2a and 7-azain-
dole.15
Discu ssion
A different behavior has been observed for triruthen-
ium and triosmium clusters in their reactions with H2-
apyPh. Triruthenium complexes analogous to the os-
mium derivatives 5 and 6 may be intermediates in the
synthesis of 1. However, they have not been detected.
While complex 1 is the first product observed in the
(13) See, for example: (a) Cabeza, J . A.; del R´ıo, I.; Grepioni, F.;
Riera, V. Organometallics 2000, 19, 4643. (b) Kong, F. S.; Kong, W. T.
J . Organomet. Chem. 1999, 589, 180. (c) Hui, B. K. M.; Wong, W. T. J .
Chem. Soc., Dalton Trans. 1998, 3977. (d) Dawoodi, Z.; Mays, M. J .;
Hendrick, K. J . Chem. Soc., Dalton Trans. 1984, 433.
(14) Deeming. A. J .; Peters, R.; Hursthouse, M. B.; Backer-Dirks,
J . D. J .J . Chem. Soc., Dalton Trans. 1982, 1205.
(15) Kong, F. S.; Wong, W. T. J . Chem. Soc., Dalton Trans. 1997,
1237.

1112 Organometallics, Vol. 23, No. 5, 2004
Cabeza et al.
spot TLC on silica gel. Photolytic reactions were carried out
in Pyrex glass water-refrigerated jacketed Schlenk tubes, using
a 400 W mercury lamp. [Os3(CO)10(MeCN)2]19 and 13CO-
enriched [Ru3(CO)12] (ca. 20% enrichment)20 were prepared as
described elsewhere. Anhydrous Me3NO was obtained by
azeotropic distillation of Me3NO‚2H2O in toluene. Instrumen-
tation was as previously reported.7 Unless otherwise stated,
NMR spectra were run at room temperature using internal
SiMe4 as standard (δ ) 0). MS data refer to the most abundant
molecular ion isotopomer.
reactions of [Ru3(CO)12] and [Ru3(CO)10(MeCN)2] with
H2apyPh, the analogous triosmium cluster 7 is only
formed forcing the elimination of CO ligands from the
decacarbonyls 5 or 6 (irradiation with UV light). These
findings should be related with the well-known fact that
it is more difficult to substitute CO ligands in osmium
than in ruthenium carbonyls.
The phenyl group of H2apyPh rotates freely about the
C-C bond that connects it with the pyridine fragment.
This accounts for the fact that the chemistry described
herein for H2apyPh is considerably different from that
reported for H2abqH, which is planar and rigid, for
which only two ruthenium and one osmium derivatives
are known, namely, [Ru3(µ3-η3-Habq-N,N,C)(CO)9] (Chart
1), [Ru3(µ-Η)2(µ3-η3-Habq-N,N,C)2(CO)6], and [Os3(µ-Η)-
(µ-η1-HabqH-N)(CO)10] (Chart 1).7 The latter two com-
pounds are structurally analogous to the H2apyPh
derivatives 2 and 5, respectively. Steric reasons explain
why no species derived from H2abqH analogous to
compounds 1, 3, 6, and 7 are known (if the benzo ring
is not metalated, it hampers the coordination of the
pyridine N atom). Curiously, the metalated complex
[Ru3(µ3-η3-Habq-N,N,C)(CO)9] is unique in that no
related species derived from H2apyPh is known.
The hexanuclear complexes 3 and 4 are noteworthy
because of their uncommon metallic skeleton, basal
edge-bridged square pyramid. To date, very few hexaru-
thenium cluster complexes of this type that have been
reported, and they have been prepared in several steps
from [Ru3(CO)12] in low overall yields.12,16,17 In fact, no
efficient syntheses of hexanuclear complexes containing
a basal edge-bridged square pyramidal metallic skeleton
have hitherto been reported. It is interesting that the
herein reported synthesis of compound 3 represents the
first one-pot preparation of clusters of this type directly
from [Ru3(CO)12]. Although the yields of compounds 3
and 4 are not high, these results led us to extend this
synthetic method to no cyclometalable 2-aminopyr-
idines. In this case, high yields of hexaruthenium
derivatives have been obtained,9 and this has allowed
the study of their reactivity.18
2-Am in o-6-p h en ylp yr id in e.
A suspension containing
2-phenylpyridine (5 mL, 0.035 mol), NaNH2 (6.76 g, 0.173 mol),
and N,N-dimethylaniline (15 mL) was heated at 160 °C for
3.5 h. The color changed from yellow to green and finally to
dark violet. The solvent was removed under reduced pressure,
and the oily red residue was hydrolyzed with water (10 mL).
The aqueous phase was extracted with diethyl ether (3 × 15
mL), and the combined extracts were dried with anhydrous
Na2SO4. The dried solution was evaporated to dryness to give
a red-orange oil, which was washed with hexane (3 × 10 mL)
to give the product as a yellow solid (2.09 g, 35%). Anal. Calcd
for C11H10N2 (fw ) 170.21): C, 72.62; H, 5.92; N, 16.46.
Found: C, 72.91; H, 6.01; N, 16.37. EI-MS (m/z): 171 [(M +
1
1)+]. H NMR (CDCl3): δ 7.94 (d, br, J ) 8.0 Hz, 2 H), 7.53-
7.38 (m, 4 H), 7.09 (d, J ) 7.4 Hz, 1 H), 6.45 (d, J ) 8.0 Hz, 1
H), 4.54 (s, br, 2 H, NH2). 13C{1H} NMR, DEPT (CDCl3): δ
158.6 (C), 158.4 (C), 140.0 (C), 138.6 (CH), 128.9 (CH), 128.8
(2 CH), 127.1 (2 CH), 111.2 (CH), 107.4 (CH).
[Ru 3(µ-H)(µ3-η2-Ha p yP h -N,N)(CO)9] (1). A solution of
Me3NO (39 mg, 0.520 mmol) in dichloromethane (10 mL) was
slowly added to a cold (-78 °C) solution of [Ru3(CO)12] (150
mg, 0.235 mmol) in 10:1 dichloromethane-acetonitrile (110
mL). After stirring for 10 min, solid H2apyPh (48 mg, 0.282
mmol) was added. The solution was allowed to warm to room
temperature, and the solvent was removed under reduced
pressure. THF (40 mL) was added, and the resulting solution
was stirred for 2 h. The solvent was removed under reduced
pressure, and the residue was dissolved in dichloromethane
(2 mL). This solution was separated by column chromatogra-
phy on silica gel (2 × 10 cm). Hexane eluted some [Ru3(CO)12].
Hexane-dichloromethane (1:1) eluted an orange band that
afforded compound 1 upon solvent removal (25 mg, 15%). Anal.
Calcd for C20H10N2O9Ru3 (fw ) 725.55): C, 33.11; H, 1.39; N,
3.86. Found: C, 33.21; H, 1.25; N, 3.75. FAB-MS (m/z): 727
[M+]. IR (CH2Cl2): νCO 2079 (m), 2050 (s), 2026 (vs), 1997 (s),
1
1987 (m), 1961 (w) cm-1. H NMR (CD2Cl2): δ 7.60-7.49 (m,
The low tendency of osmium carbonyls to substitute
their CO ligands may also explain why all attempts to
make hexaosmium derivatives analogous to compound
3, by treating complex 7 with [Os3(CO)10(MeCN)2], were
unsuccessful. Attempts to prepare mixed-metal Os3Ru3
complexes, by treating either 1 with [Os3(CO)10(MeCN)2]
or complex 7 with [Ru3(CO)10(MeCN)2], also failed.
3 H), 7.51 (t, J ) 7.7 Hz, 1 H), 7.34-7.30 (m, 2 H), 6.79 (dd, J
) 7.7, 1.2 Hz, 1 H), 6.61 (dd, J ) 7.7, 1.2 Hz, 1 H), 4.68 (s, br,
1 H, NH), -11.25 (s, 1 H). 13C{1H} NMR, DEPT (Me2CO-d6):
δ 204.3 (CO), 203.5 (2 CO), 200.9 (2 CO), 199.9 (2 CO), 186.2
(2 CO), 180.9 (C), 165.2 (C), 143.5 (C), 140.8 (CH), 130.7 (CH),
130.5 (2 CH), 130.0 (2 CH), 121.9 (CH), 112.6 (CH).
[Ru 3(µ-H)2(µ3-η3-Ha p yC6H4-N,N,C)2(CO)6] (2). A solution
of compound 1 (70 mg, 0.097 mmol) and H2apyPh (16 mg, 0.094
mmol) in toluene (25 mL) was stirred at reflux temperature
for 135 min. The color changed from orange to deep red. The
solvent was removed under reduced pressure and the residue
washed with hexane (2 × 5 mL) to give compound 2 as an
orange-yellow solid (75 mg, 96%). Anal. Calcd for C28H18N4O6-
Ru3 (fw ) 809.69): C, 41.54; H, 2.24; N, 6.92. Found: C, 41.63;
H, 2.26; N, 6.85. FAB-MS (m/z): 811 [M+]. IR (CH2Cl2): νCO
2051 (vs), 2030 (s), 1976 (s) cm-1. 1H NMR (CDCl3): δ 8.06 (d,
J ) 7.5 Hz, 1 H), 7.32 (t, J ) 7.9 Hz, 1 H), 7.18 (d, J ) 7.5, Hz,
1 H), 7.06 (t, J ) 7.5 Hz, 1 H), 6.85 (d, J ) 7.9 Hz, 1 H), 6.77
(d, J ) 7.5 Hz, 1 H), 6.01 (d, J ) 7.9 Hz, 1 H), 4.32 (s, br, 1 H,
NH), -9.40 (s, 1 H). 13C{1H} NMR, DEPT (CD2Cl2): δ 199.3
(CO), 199.2 (CO), 197.9 (CO), 168.2 (C), 164.6 (C), 161.9 (C),
Exp er im en ta l Section
Gen er a l Da ta . Solvents were dried over Na[Ph2CO] (THF,
diethyl ether, hydrocarbons) or CaH2 (dichloromethane, 1,2-
dichloroethane, acetonitrile) and distilled under nitrogen prior
to use. The term “xylene” refers to the commercial mixture of
ortho, meta, and para isomers. The reactions were carried out
under nitrogen, using Schlenk-vacuum line techniques, and
were routinely monitored by solution IR spectroscopy and by
(16) (a) Adams, R. D.; Babin, J . E.; Tasi, M.; Wolfe, T. A. J . Am.
Chem. Soc. 1988, 110, 7093. (b) Adams, R. D.; Babin, J . E.; Tasi, M.
Organometallics 1988, 7, 503. (c) Adams, R. D.; Babin, J . E.; Tasi, M.;
Wolfe, T. A. New J . Chem. 1988, 12, 481. (d) Adams, R. D.; Qu, X.;
Wu, W. Organometallics 1994, 13, 1272.
(17) Chihara, T.; Tase, T.; Ogawa, H.; Wakatsuki, Y. Chem. Com-
mun. 1999, 279.
(18) Cabeza, J . A.; del R´ıo, I.; Garc´ıa-AÄ lvarez, P. Unpublished
results.
(19) Nicholls, J . M.; Vargas, M. D. Inorg. Synth. 1990, 28, 232.
(20) Andreu, P. L.; Cabeza, J . A.; Miguel, D.; Riera, V.; Villa, M. A.;
Garc´ıa-Granda, S. J . Chem. Soc., Dalton Trans. 1991, 533.

Tri- and Hexaruthenium Carbonyl Derivatives
Organometallics, Vol. 23, No. 5, 2004 1113
144.4(C), 139.5 (CH), 136.3 (CH), 129.2 (CH), 125.6 (CH), 123.3
(CH), 118.6 (CH), 111.2 (CH).
corresponding to compound 2 and an as yet unidentified
product that contains a metalated HapyC6H4 ligand (an intact
1
[Ru 6(µ3-H)2(µ5-η2-apyP h -N,N)(µ-CO)2(CO)14] (3) an d [Ru 6-
(µ3-H)(µ5-η3-a p yC6H4-N,N,C)(µ-CO)3(CO)13] (4). A solution
of [Ru3(CO)12] (100 mg, 0.157 mmol) and H2apyPh (6 mg, 0.035
mmol) in xylene (7 mL) was heated at reflux temperature for
15 min. Then, an additional amount of H2apyPh (7 mg, 0.041
mmol) was added, and the solution was heated further for 15
min. The color changed from orange to dark brown. The solvent
was removed under high vacuum, and the residue was
dissolved in dichloromethane (5 mL). This solution was placed
onto of a silica gel column (2 × 15 cm) packed in hexane.
Hexane eluted a small amount of [Ru4(µ-H)4(CO)12]. Hexane-
diethyl ether (50:1) eluted three bands. The first, dark brown,
led to compound 3 after solvent removal (33 mg, 35%). The
second, dark green, led to compound 4 after solvent removal
(10 mg, 11%). The third band, yellow, contained compound 2
(10 mg, 32%).
NH fragment was observed in the H NMR spectrum, and the
resonances of all seven CH and the three C groups of
HapyC6H4 were observed in the DEPT 13C spectra). This
compound could not be fully characterized, because it was
never obtained pure and underwent decomposition upon all
attempted chromatographic separations (it decomposed on the
chromatographic supports). Thermolysis of 1 in refluxing
toluene led to compound 2 and extensive untractable decom-
position.
Th er m olysis of Com p ou n d 3. A solution of compound 3
(20 mg, 0.016 mmol) in xylene (3 mL) was heated at reflux
temperature for 45 min. The color changed from dark brown
to very dark green. The solvent was removed under vacuum.
The 1H NMR spectrum of the crude residue indicated the
presence of complexes 3, 4, and two as yet unidentified
dihydrido derivatives X and Y, in a 1:1:1:5 ratio, respectively.
The latter two show hydride ligands at -12.70 and -13.30
(X) and -16.32 and -16.34 (Y) ppm. Compound X underwent
decomposition upon all attempted chromatographic separa-
tions (it decomposed on the chromatographic supports). Com-
pound Y, dark green, was successfully separated. Its analysis
Da ta for 3. Anal. Calcd for C27H10N2O16Ru6 (fw ) 1224.86):
C, 26.48; H, 0.82; N, 2.29. Found: C, 26.44; H, 0.75; N, 2.32.
FAB-MS (m/z): 1198 [(M - CO)+]. IR (CH2Cl2): νCO 2094 (m),
2069 (s), 2048 (s), 2032 (vs), 2013 (m, sh), 1994 (w, sh), 1972
(m), 1951 (w, sh), 1859 (m, br), 1827 (m, br) cm-1 1H NMR
.
1
(CD2Cl2): δ 7.57-7.48 (m, 3 H), 7.32 (dd, J ) 8.3, 7.5 Hz, 1
H), 7.20 (d, br, J ) 7.1 Hz, 1 H), 7.11 (d, br, J ) 7.5 Hz, 1 H),
6.62 (dd, J ) 7.1, 1.2 Hz, 1 H), 5.90 (dd, J ) 8.3, 1.2 Hz, 1 H),
-11.46 (d, J ) 2.4 Hz, 1 H), -15.87 (d, J ) 2.4 Hz, 1 H). 13C-
{1H} NMR, DEPT (CD2Cl2): δ 233.6 (CO), 202.3 (CO), 199.2
(CO), 195.9 (CO), 195.3 (CO), 194.8 (CO), 193.7 (CO), 193.3
(CO), 188.3 (C), 186.1 (CO), 182.3 (CO), 182.0 (CO), 161.2 (C),
140.3 (C), 139.3 (CH), 130.0 (CH), 129.2 (3 CH), 128.5 (CH),
121.1 (CH), 116.5 (CH).
and H NMR spectrum suggested the presence of coordinated
xylene, but its structure has not yet been determined. Themol-
ysis of 1 in diglime (140 °C, 3 h) led to a 1:0.5:0.8 mixture of
3, 4, and X.
Hyd r ogen a tion of Com p ou n d 4. Hydrogen was slowly
bubbled for 1 h through a solution of complex 4 (10 mg, 0.008
mmol) in THF (20 mL) at reflux temperature. The color
changed from dark green to dark brown. The IR spectrum of
this solution indicated the quantitative transformation of
complex 4 into 3.
[Os3(µ-H)(µ-η1-Ha p yP h -N)(CO)10] (5) a n d [Os3(µ-H)(µ-
η2-Ha p yP h -N,N)(CO)10] (6). A THF solution (20 mL) of H2-
apyPh (25 mg, 0.147 mmol) and [Os3(CO)10(MeCN)2] (100 mg,
0.107 mmol) was stirred at room temperature for 4 h and 30
min. The color changed from lime yellow to yellow. The solvent
was removed under reduced pressure, the residue was dis-
solved in dichloromethane (1 mL), and the resulting solution
was separated by TLC on silica gel. Hexane-dichloromethane
(2:1) eluted five yellow bands that were extracted with
dichloromethane and afforded, in order of elution, a trace
amount of [Os3(CO)12], [Os3(µ-H)(µ-η1-HapyPh-N)(CO)10] (5) (12
mg, 11%), [Os3(µ-H)(µ-η2-HapyPh-N,N)(CO)10] (6) (60 mg, 55%),
[Os3(µ-H)(µ3-η2-HapyPh-N,N)(CO)9] (7) (5 mg, 5%), and a trace
amount of an as yet unidentified compound.
Da ta for 4. Anal. Calcd for C27H8N2O16Ru6 (fw ) 1222.86):
C, 26.52; H, 0.66; N, 2.29. Found: C, 26.41; H, 0.57; N, 2.22.
FAB-MS (m/z): 1224 [M+]. IR (CH2Cl2): νCO 2088 (m), 2050
(vs), 2028 (m), 2014 (m), 1997 (w, sh), 1961 (w, sh), 1880 (w),
1
1860 (m), 1841 (w) cm-1. H NMR (CD2Cl2): δ 7.85 (dd, J )
7.5, 0.8 Hz 1 H), 7.64 (dd, J ) 7.9, 1.6 Hz, 1 H), 7.39 (td, J )
7.5, 1.6 Hz, 1 H), 7.24-7.13 (m, 3 H), 5.15 (d, J ) 7.1 Hz, 1
H), -16.62 (s, br, 1 H). 13C{1H} NMR, DEPT (CD2Cl2): δ 238.6
(CO), 230.2 (br, CO), 197.2 (CO), 195.1 (CO), 194.7 (CO), 193.1
(CO), 186.3 (C), 180.1 (CO), 162.8 (C), 161.6 (C), 142.2 (C),
139.1 (CH), 137.9 (CH), 132.6 (CH), 126.0 (CH), 124.7 (CH),
115.6 (CH), 111.6 (CH).
Rea ction of [Ru 3(CO)12] w ith 2.2 Equ iv of H2a p yP h . A
solution of [Ru3(CO)12] (100 mg, 0.156 mmol) and H2apyPh (58
mg, 0.341 mmol) in toluene (20 mL) was heated at reflux
temperature for 3 h. The color changed from orange to dark
brown. The solvent was removed under high vacuum. A 1H
NMR spectrum of the residue showed the presence of com-
pounds 1, 2, 3, and [Ru4(µ-H)4CO)12] in 6:100:12:1.5 molar
ratio.
Da ta for 5. Anal. Calcd for C21H10N2O10Os3 (fw ) 1020.92):
C, 24.71; H, 0.99; N, 2.74. Found: C, 24.77; H, 1.06; N, 2.71.
FAB-MS (m/z): 1022 [M+]. IR (CH2Cl2): νCO 2103 (w), 2067
1
(s), 2051 (m), 2015 (m), 1994 (m, br), 1977 (w) cm-1. H NMR
(CD2Cl2): δ 8.08 (d, J ) 8.1 Hz, 1 H), 8.08 (d, J ) 7.7 Hz, 1
H), 7.63 (t, J ) 7.7 Hz, 1 H), 7.54-7.47 (m, 4 H), 6.88 (d, J )
7.7 Hz, 1 H), 5.94 (s, br, 1 H, NH), -14.03 (d, J ) 2.6 Hz, 1
H). 13C{1H} NMR, DEPT (CD2Cl2): δ 190.1 (CO), 181.6 (CO),
177.5 (2 CO), 176.5 (2 CO), 172.5 (4 CO), 170.0 (C), 155.3 (C),
138.7 (CH), 137.3 (C), 129.5 (CH), 128.6 (2 CH), 126.7 (2 CH),
116.8 (CH), 110.8 (CH).
Rea ction of Com p ou n d 1 w ith [Ru 3(CO)12]. A solution
of compound 1 (50 mg, 0.069 mmol) and [Ru3(CO)12] (44 mg,
0.069 mmol) in toluene (25 mL) was stirred at reflux temper-
ature until the complete disappearance of [Ru3(CO)12] was
observed by IR spectroscopy (ca. 105 min). The color changed
from orange to dark brown. The solvent was removed under
high vacuum, and the residue was dissolved in dichlo-
romethane (3 mL). This solution was placed onto a silica gel
column (2 × 15 cm) packed in hexane. Hexane eluted some
[Ru4(µ-H)4(CO)12]. Hexane-diethyl ether (50:1) eluted three
bands. The first, dark brown, led to compound 3 after solvent
removal (6 mg, 7%). The second, dark green, led to compound
4 after solvent removal (4 mg, 5%). The third band, yellow,
contained compound 2 (12 mg, 21%).
Da ta for 6. Anal. Calcd for C21H10N2O10Os3 (fw ) 1020.92):
C, 24.71; H, 0.99; N, 2.74. Found: C, 24.81; H, 1.04; N, 2.69.
FAB-MS (m/z): 1022 [M+]. IR (CH2Cl2): νCO 2104 (m), 2064
1
(vs), 2054 (s), 2015 (s, br), 1993 (m), 1979 (w) cm-1. H NMR
(CD2Cl2): 7.60-7.43 (m, 4 H), 6.90 (d, br, J ) 8.0 Hz, 1 H),
6.83 (dd, J ) 8.7, 6.8 Hz, 1 H), 6.22 (dd, J ) 8.7, 1.2 Hz, 1 H),
5.91 (dd, J ) 6.8, 1.2 Hz, 1 H), 4.52 (s, br, 1 H, NH), -11.82
(s, 1 H). 13C{1H} NMR, DEPT (CD2Cl2): δ 183.7 (CO), 182.4
(CO), 178.0 (CO), 177.4 (CO), 176.1 (CO), 175.1 (CO), 174.2
(CO), 173.9 (CO), 172.7 (CO), 172.6 (CO), 170.2 (C), 160.7 (C),
145.4 (C), 134.7(CH), 129.9 (CH), 129.3 (CH), 128.9 (CH), 128.8
(CH), 128.4 (CH), 117.0 (CH), 109.9 (CH).
Th er m olysis of Com p ou n d 1. Compound 1 (50 mg, 0.069
mmol) was heated in 1,2-dichloroethane at reflux temperature
for 5 h. The solvent was removed under vacuum. The 1H NMR
spectrum of the crude residue indicated the presence of two
hydrido derivatives, with hydride integrals in a 1:4 ratio,

1114 Organometallics, Vol. 23, No. 5, 2004
Ta ble 3. Cr ysta l, Mea su r em en t, a n d Refin em en t Da ta for 3‚(CH2Cl2)0.5, 4, a n d 7
Cabeza et al.
3‚(CH2Cl2)0.5
4
7
formula
fw
C
27.5H11ClN2O16Ru6
C
27H8N2O16Ru6
C20H10N2O9Os3
992.90
1267.25
1222.77
cryst syst
space group
a, Å
b, Å
c, Å
â, deg
vol, Å3
Z
monoclinic
P21/c
monoclinic
P21/c
monoclinic
P21/a
11.8240(3)
15.0404(4)
19.4733(5)
95.778(2)
3445.5(1)
4
10.1497(3)
10.6673(3)
30.1217(9)
92.410(2)
3258.4(1)
4
16.0037(5)
8.2977(3)
17.6828(6)
101.808(2)
2298.5(1)
4
F(000)
D
2396
2.443
2304
2.493
1776
2.869
calcd, g cm-3
radiation (λ, Å)
Cu KR (1.54180)
Cu KR (1.54180)
Cu KR (1.54180)
µ, mm-1
22.166
22.667
31.131
cryst size, mm
temp, K
0.12 × 0.10 × 0.10
120(2)
0.10 × 0.08 × 0.05
120(2)
0.15 × 0.10 × 0.07
120(2)
θ limits, deg
3.72 to 68.37
0/14, 0/18, -23/22
33 790
6283
5557
XABS
0.112/0.080
495/0
2.94 to 68.28
0/12, 0/12, -36/36
65 586
5973
4727
SORTAV
0.320/0.164
460/0
2.55 to 68.35
-19/18, 0/10, 0/21
39 106
4219
3706
SORTAV
0.095/0.062
310/7
min./max. h, k, l
no. of reflns collected
no. of unique reflns
no. of reflns with I > 2σ(I)
absorp corr
max./min. transmn
no. of params/restraints
GOF on F2
1.056
1.017
1.048
final R1 (on F, I > 2σ(I))
final wR2 (on F2, all data)
max./min. ∆F, e Å-3
0.0304
0.1012
1.598/-1.009
0.0450
0.1452
1.999/-1.319
0.0524
0.1357
2.851/-2.925
[Os3(µ-H)(µ3-η2-Ha p yP h -N,N)(CO)9] (7). A THF solution
(20 mL) of compound 6 (30 mg, 0.029 mmol) was irradiated
with UV light for 5 min, maintaining a gentle bubbling of
dinitrogen through the solution. No color change was observed,
but the IR spectrum showed the complete disappearance of
the starting material. The solvent was removed under reduced
pressure, and the residue was washed with hexane (2 × 5 mL)
to give complex 7 as a yellow solid (26 mg, 90%). Similar
results were obtained using compound 5 as starting material.
Anal. Calcd for C20H10N2O9Os3 (fw ) 992.91): C, 24.19; H, 1.02;
N, 2.82. Found: C, 24.33; H, 1.08; N, 2.80. FAB-MS (m/z): 994
[M+]. IR (CH2Cl2): νCO 2081 (w), 2051 (vs), 2022 (s), 1991 (s),
6.36 (d, J ) 8.5 Hz, 1 H), 4.35 (s, br, 1 H, NH), -13.02 (s, 1
H), -13.32 (s, 1 H). 13C{1H} NMR, DEPT (CD2Cl2): δ 181.8
(CO), 175.0 (CO), 174.7 (CO), 174.5 (CO), 174.3 (CO), 173.3
(CO), 172.2 (CO), 171.1 (CO), 169.9 (CO), 166.6 (C), 162.2 (C),
146.6 (C), 144.5 (C), 139.4 (CH), 134.7 (CH), 129.8 (CH), 124.0
(CH), 123.3 (CH), 114.4 (CH), 101.9 (CH).
X-r a y Str u ctu r es of Com p ou n d s 3‚(CH2Cl2)0.5, 4, a n d
7. A selection of crystal, measurement, and refinement data
are given in Table 3. Diffraction data were collected on a
Nonius Kappa-CCD diffractometer equipped with a 95 mm
CCD camera on a κ-goniostat, using graphite-monochromated
2
Cu KR radiation. Data were reduced to Fo values. Empirical
1978 (m), 1954 (w), 1943 (w) cm-1. H NMR (CD2Cl2): 7.65 (t,
absorption corrections were applied using XABS221 for 3‚(CH2-
Cl2)0.5 or SORTAV22 for 4 and 7. The structures were solved
by Patterson interpretation using the program DIRDIF-96.23
Isotropic and full matrix anisotropic least-squares refinements
were carried out using SHELXL-97.24 The dichloromethane
solvent molecule of 3‚(CH2Cl2)0.5 was disordered over two
equally populated positions. All non H atoms were refined
anisotropically. Hydrogen atoms H100 and H200 of 3‚(CH2-
Cl2)0.5 were located in the corresponding Fourier maps, and
their coordinates and thermal parameters were refined. The
positions of the hydrides H100 of 4 and 7 were calculated using
the program XHYDEX,25 and their coordinates and thermal
parameters were fixed. All the remaining hydrogen atom
positions were geometrically calculated and were refined riding
on their parent atoms, except for H1 of compound 7, which
was refined with fixed N-H bond distance and fixed thermal
parameter. The molecular plots were made with the EUCLID
program package.26 The WINGX program system27 was used
throughout the structure determinations.
1
J ) 7.8 Hz, 1 H), 7.57-7.30 (m, 5 H), 6.80 (dd, J ) 7.8, 1.2
Hz, 1 H), 6.60 (dd, J ) 7.8, 1.2 Hz, 1 H), 5.05 (s, br, 1 H, NH),
-12.82 (s, 1 H). 13C{1H} NMR, DEPT (CD2Cl2): δ 188.8 (2 CO),
179.9 (2 CO), 177.3 (3 CO), 174.8 (2 CO), 171.4 (C), 164.9 (C),
142.0 (C), 137.8 (CH), 129.3 (CH), 128.9 (2 CH), 128.2 (2 CH),
121.2 (CH), 112.5 (CH).
Th er m olysis of Com p ou n d s 5 a n d 7. A solution of 5 (20
mg, 0.020 mmol) in toluene (20 mL) was heated at reflux
temperature for 5 h. The IR spectrum of the solution showed
only the presence of the starting material. Identical results
were obtained using 7 as starting material.
[Os3(µ-H)2(µ-η3-Ha p yC6H4-N,N,C)(CO)9] (8). A solution of
compound 6 (45 mg, 0.044 mmol) in toluene was heated at
reflux temperature for 25 min. No color change was observed.
The solvent was removed under reduced pressure, the residue
was dissolved in THF (5 mL), and the resulting solution was
separated by TLC on silica gel. Hexane-dichloromethane (2:
1) eluted three yellow bands. The first one, in order of elution,
contained complex 5 (7 mg, 16%). The second band yielded
complex 8 (15 mg, 34%). The third one gave complex 7 (4 mg,
8%). Compound 8 is unstable in solution at room temperature,
being transformed into complex 7 over a period of several days
under visible light. Anal. Calcd for C20H10N2O9Os3 (fw )
992.91): C, 24.19; H, 1.02; N, 2.82. Found: C, 24.26; H, 1.10;
N, 2.77. FAB-MS (m/z): 994 [M+]. IR (CH2Cl2): νCO 2127 (w),
(21) Parkin, S.; Moezzi, B.; Hope H. J . Appl. Crystallogr. 1995, 28,
53.
(22) Blessing, R. H. Acta Crystallogr. 1995, A51, 33.
(23) Beurskens, P. T.; Beurskens, G.; Bosman, W. P.; de Gelder, R.;
Garc´ıa-Granda, S.; Gould, R. O.; Israe¨l, R.; Smits, J . M. M. The
DIRDIF-96 Program System; Crystallography Laboratory, University
of Nijmegen: The Netherlands, 1996.
(24) Sheldrick, G. M. SHELXL97, version 97-2; University of
Go¨ttingen: Germany, 1997.
(25) Orpen, A. G. J . Chem. Soc., Dalton Trans. 1980, 2509.
(26) Spek, A. L. The EUCLID Package. In Computational Crystal-
lography; Sayre, D., Ed.; Clarendon Press: Oxford, UK, 1982; p 528.
(27) Farrugia, L. J . J . Appl. Crystallogr. 1999, 32, 837.
2075 (m), 2048 (s), 2032 (m), 1995 (w), 1986 (w), 1953 (w) cm-1
.
1H NMR (CD2Cl2): 8.16 (d, J ) 7.2 Hz, 1 H), 7.72 (d, J ) 8.5
Hz, 1 H), 7.27 (td, J ) 7.2 1.2 Hz, 1 H), 7.18 (td, J ) 7.2 1.2
Hz, 1 H), 7.02 (t, J ) 8.5 Hz, 1 H), 6.85 (d, J ) 7.2 Hz, 1 H),

Tri- and Hexaruthenium Carbonyl Derivatives
Organometallics, Vol. 23, No. 5, 2004 1115
Su p p or tin g In for m a tion Ava ila ble: Crystallographic
data in CIF format for 3‚(CH2Cl2)0.5, 4, and 7. This material
is available free of charge via the Internet at http://pubs.acs.
org.
Ack n ow led gm en t. This work has been supported
by the Spanish DGESIC (grant PB98-1555 to J .A.C.),
CICYT (grants BQU2000-2019 to S.G.-G. and BQU2002-
2623 to J .A.C.), and Principado de Asturias (grant PR-
01-GE-7 to V.R.).
OM034040Y