Reactions of hydrogen with ruthenium and osmium complexes containing tridentate ligands Cy2PCH2CH(CH2) 2PCy2 and 2,6-(Ph2PCH2) 2C6H3

Article abstract of DOI:10.1016/S0020-1693(02)00750-8

Reaction of cis-1,4-dichlorobut-2-ene with dicyclohexylphosphine in the presence of KI in acetone produces [cis-Cy₂PHCH₂CH= CHCH₂PHCy₂]I₂, which is converted to cis-Cy₂PCH₂CH=CHC

Full text of DOI:10.1016/S0020-1693(02)00750-8

Inorganica Chimica Acta 334 (2002) 122Á130
/
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Reactions of hydrogen with ruthenium and osmium complexes
containing tridentate ligands Cy2PCH2CH(CH2)2PCy2 and 2,6-
(Ph2PCH2)2C6H3
Sheng Hua Liu a, Shu Tak Lo a, Ting Bin Wen a, Ian D. Williams a, Zhong Yuan Zhou b,
Chak Po Lau b,*, Guochen Jia a,*
a Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
b Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
Received 17 September 2001; accepted 20 November 2001
Abstract
Reaction of cis-1,4-dichlorobut-2-ene with dicyclohexylphosphine in the presence of KI in acetone produces [cis-Cy2PHCH2CHÄ
CHCH2PHCy2]I2, which is converted to cis-Cy2PCH2CHÄCHCH2PCy2 on treatment with NaOH. Reactions of cis-Cy2PCH2CHÄ
CHCH2PCy2 with MHCl(CO)(PPh3)3 (MꢀRu, Os) yield MHCl(CO)(PPh3)(Cy2PCH2CHÄCHCH2PCy2). The ruthenium complex
RuCl(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2) is obtained by refluxing RuHCl(CO)(PPh3)(Cy2PCH2CHÄCHCH2PCy2) in methanolÁ
CH2Cl2. Reaction of RuCl(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2) with H2 in the presence of NaBPh4 produces
RuHCl(CO)(PPh3)(Cy2P(CH2)4PCy2). Reaction of OsCl(PPh3)(2,6-(Ph2PCH2)2C6H3) with H2 produces OsCl(H H)(PPh3)(2,6-
/
/
/
/
/
/
/
/
Á Á Á
/
(Ph2PCH2)2C6H3) which contains an elongated dihydrogen ligand. # 2002 Elsevier Science B.V. All rights reserved.
Keywords: Ruthenium; Osmium; Hydrides; PCP
1. Introduction
olefins and acetylenes catalyzed by Group 8 metal
complexes such as [MH(H2)(PP3)]ꢁ (Mꢀ
Fe, Ru;
(PP3ꢀPCH2CH2PPh2)3) [5], OsHCl(CO)(P(i-Pr)3)2 [6],
RuHCl(PPh3)3 [7] and TpRuH(L)(PPh3) (LꢀPPh3,
/
Since the first report of dihydrogen complexes by
Kubas and coworkers in 1984 [1], this unique class of
complexes have been intensively investigated, especially
for their preparation, characterization, structural, and
/
/
CH3CN) [8]. However, the proposed dihydrogen inter-
mediates are usually too reactive to be observed. In fact,
well characterized dihydrogen complexes containing s-
bonded carbon ligands are still rare, despite the fact that
a large number of dihydrogen complexes have been
reported [2]. Reported dihydrogen complexes containing
a s-bonded carbon ligand are limited to a few of those
catalytic properties [2Á4]. Previous studies have estab-
/
lished that dihydrogen complexes can have unique
reactivity and play active roles in catalytic reactions.
In catalytic hydrogenation reactions, there are several
possible ways in which dihydrogen complexes can play
their active roles [3]. Among them, intramolecular
hydrogen transfer from a coordinated dihydrogen
ligand to the a-carbon of a s-bonded carbon ligand
has been recognized as one of the key steps in the
catalytic cycles. In particular, alkyl-dihydrogen and
alkenyl-dihydrogen complexes have been proposed or
implied as the key intermediates in the hydrogenation of
with alkynyl ligands (for example, [Ru(H2)(CÅ
(dippe)2]BPh4 [9] OsH(H2)(CÅCPh)(CO)(P(i-Pr)3)2 [10])
and aryl ligands (for example, OsCl(H2)(NHꢀ
CPhC6H4)(P(i-Pr)3)2 [11], [IrH(H2)(bq)(PPh3)2]ꢁ (bqꢀ
/CPh)-
/
/
/
7,8-benzoquinolinate)
Pr)2PCH2)2C6H3)
[12],
OsH(H2)(CO)(2,6-((i-
[13],
CHC6H4)(P(i-Pr)3)2 [14]).
and
RuCl(H2)(MeNÄ
/
In order to further model intramolecular hydrogen
transfer from a dihydrogen ligand to the a carbon of a
s-bonded carbon ligand, we have investigated the
reactions of M(R)(L)n with H2, with the hope to observe
* Corresponding authors. Tel.: ꢁ852-23-58 7361; fax: ꢁ852-23-58
1594.
E-mail address: chjiag@ust.hk (G. Jia).
0020-1693/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 0 - 1 6 9 3 ( 0 2 ) 0 0 7 5 0 - 8

S.H. Liu et al. / Inorganica Chimica Acta 334 (2002) 122Á
/130
123
dihydrogen complexes M(R)(H2)(L)n (Rꢀ
/
s-bonded
13C{1H} NMR spectrum (in C6D6), the olefinic carbon
signal was observed at 127.1 ppm.
carbon ligands) or the hydrogen transferred products.
In this report, we wish to describe the reactions of H2
with ruthenium and osmium complexes with PCP-type
chelating ligands Cy2PCH2CH(CH2)2PCy2 and 2,6-
(Ph2PCH2)2C6H3.
2.2. Synthesis of
RuCl(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2)
Iron group dihydrogen complexes of the type
[M(R)(H2)(L)4]ꢁ have been proposed as the key inter-
mediates in catalytic hydrogenation reactions [5]. Reac-
2. Results and discussion
tions of MHCl(Et2PCH2CH2PEt2)2 (MꢀFe, Ru, Os)
/
2.1. Preparation and characterization of cis-
with H2 in the presence of NaBPh4 have been shown to
give the corresponding dihydrogen complexes
[MH(H2)(Et2PCH2CH2PEt2)2]ꢁ [17]. In order to model
reactions involving [M(R)(H2)(L)4]ꢁ, the synthesis of
the formally alkyl complexes MCl(CO)(PPh3)-
Cy2PCH2CHÄ/CHCH2PCy2
Reactions of H2 with coordinately unsaturated com-
plexes or complexes with labile ligands are one of the
common approaches to prepare dihydrogen complexes
[2]. Thus one might expect that M(alkyl)(H2)(L)n may
be obtained from the reactions of H2 with M(alkyl)(L)n.
With the hope to produce observable alkyl-dihydrogen
complexes, we have studied the reactions of H2 with
alkyl complexes in which alkyl is part of a chelating
ligand. One way to prepare such alkyl complexes is to
react metal hydride complexes with a diphosphine
ligand containing an olefinic functionality in the back-
bone, since metal-alkyl linkage could be introduced by
(Cy2PCH2CH(CH2)2PCy2)(PPh3) (MꢀRu, Os) was
/
attempted, hoping that subsequent reactions of H2
with MCl(CO)PPh3)(Cy2PCH2CH(CH2)2PCy2) in the
presence of NaBPh4 would produce the dihydrogen
complexes
PCy2)]ꢁ.
[M(H2)(CO)(PPh3)(Cy2PCH2CH(CH2)2-
The ruthenium complex RuCl(CO)(PPh3)(Cy2PCH2-
CH(CH2)2PCy2) (6) can be prepared according to the
sequence shown in Scheme 2. Treatment of
RuHCl(CO)(PPh3)3 (4) with ligand 3 in benzene pro-
insertion of the olefin functionality to MÃ
this work, the ligand cis-Cy2PCH2CHÄCHCH2PCy2
was used.
The synthetic route to the ligand cis-Cy2PCH2CHÄ
/
H bonds. In
duced RuHCl(CO)(PPh3)(Cy2PCH2CHÄ
/
CHCH2PCy2)
/
(5). The structure of compound 5 can be readily assigned
1
by its H, 13C{1H} and 31P{1H} NMR spectroscopic
1
data. In the H NMR spectrum (in C6D6), the olefinic
/
CHCH2PCy2 (3) is outlined in Scheme 1. Reaction of
cis-1,4-dichlorobut-2-ene (1) with dicyclohexylpho-
sphine in the presence of KI in acetone produced [cis-
proton signal was observed at 5.87 ppm. That the
chemical shift of the olefinic proton is close to that of
free ligand is indicative of olefin double bond not
Cy2PHCH2CHÄ
/
CHCH2PHCy2]I2 (2) (Scheme 1). The
purpose of KI here is to increase the rate of nucleophilic
substitution of the halide by dicyclohexylphosphine.
Pure compound 2 was isolated as a white powder in
approximately 60% yield. The phosphonium salt 2 in
ether could be readily deprotonated by aqueous NaOH
to give cis-Cy2PCH2CHÄ
/
CHCH2PCy2 (3), which was
obtained as a pale yellow viscous liquid in 94% yield.
Similar reactions have been previously used to prepare
phosphine ligands such as trans-(t-Bu)2P(CH2)2CHÄ
/
CH(CH2)2P(t-Bu)2 [15] and 2,6-(R2PCH2)2C6H4 (Rꢀ
/
1
t-Bu, Cy) [16]. Ligand 3 has been characterized by H,
31P{1H} and 13C{1H} NMR spectroscopy. In particular,
1
the H NMR spectrum (in C6D6) displayed the olefinic
proton signal at 5.83 ppm, the 31P{1H} NMR spectrum
(in C6D6) exhibited a singlet at ꢂ3.9 ppm. In the
/
Scheme 1.
Scheme 2.

124
S.H. Liu et al. / Inorganica Chimica Acta 334 (2002) 122Á130
/
coordinating to the ruthenium center. The hydride
signal was observed at ꢂ
7.15 ppm (ddd, 2J(PH)ꢀ
molecular geometry of 6 around ruthenium can be
described as a distorted octahedron with the chloride
ligand trans to the CO ligand. The distortion can be
mainly attributed to the small bite angle of the tridentate
/
/
2
102.8, 27.9, 23.6 Hz). The presence of a large J(PH)
coupling (102.8 Hz) implies that the hydride is trans to a
phosphorus atom. In the 31P{1H} NMR spectrum (in
C6D6), complex 5 exhibited three sets of doublet of
doublets signals at 6.1, 33.0 and 37.4 ppm, indicating
that there are three non-equivalent phosphorus atoms.
ligand, as indicated by the small P(1)Ã
(146.98(9)8). As expected, the P(1)ÃRu(1)Ã
(65.7(2)8) is significantly smaller than that of P(2)Ã
Ru(1)ÃC(2) (81.3(2)8). The Ru(1)ÃC(2) bond distance
of 2.145(8) A is within the range reported for RuÃ
C(sp3)
bond distances of ruthenium-alkyl complexes (for ex-
ample,
[Ru(CH2CH2OMe)(CO)(PMe(t-Bu)2)2]ꢁ
(2.068(13) A) [19], and Ru(C(CO2Me)ꢀ
/
Ru(1)Ã
/
P(2) angle
/
/
C(2) angle
/
/
/
2
˚
The signals at 33.0 and 37.4 ppm has a large J(PP)
/
coupling constant (274.5 Hz), suggesting that two of the
phosphorus atoms in 5 are trans to each other. A 31P-1H
COSY experiment indicates that signals at 33.0 and 37.4
ppm are associated with PPh3 and PCy2, respectively.
Consistent with the structure, the carbonyl ligand in the
13C{1H} NMR spectrum (in C6D6) exhibited a triplet of
doublets signal at 204.0 ppm with small 2J(PC) coupling
constants (13.5, 8.5 Hz).
The ruthenium complex RuCl(CO)(PPh3)(Cy2PCH2-
CH(CH2)2PCy2) (6) could be obtained by refluxing
complex 5 in a mixed solvent of dichloromethane and
methanol. Pure sample of complex 6 could be obtained
as a white crystalline solid by recrystallization from
benzene/methanol. The compound has been character-
ized by NMR spectroscopy, elemental analysis and X-
ray diffraction.
˚
/CHCO2-
˚
Me)(CH(CO2Me)CH2CO2Me)(dppe) (2.241(4) A) [20]).
A number of ruthenium complexes containing triden-
tate PCP-type ligands 2,6-(R2PCH2)2C6H3 have been
reported recently [21]. In these complexes, the ruthe-
nium is bound to two PR2 groups and an aryl group.
Complex 6 represents a rare example of ruthenium
complexes with a PCP-type tridentate ligand in which
the ruthenium is linked to a sp3-hybridized carbon and
two PR2 groups [22].
Complex 6 was produced by refluxing complex 5 in
the mixed solvent of methanol and dichloromethane.
For insertion of an olefin to a MÃ
/
H bond to take place,
coordination of the olefin to give a hydrido-olefin
complex is usually required [23]. In the conversion of
In the 1H NMR spectrum of complex 6, neither
hydride nor olefinic proton signal was observed, imply-
ing that an insertion reaction has occurred and a
ruthenium-carbon bond has been formed. In the
13C{1H} NMR spectrum (in CDCl3), the signal of the
carbonyl ligand appeared as a triplet of doublets at
5Á6, coordination of the olefin double bond could occur
/
by either dissociation of the chloride or the PPh3 ligand
in 5. It was found that the complex 5 could not be
converted to 6 in benzene even under reflux. It can also
be demonstrated that complex 5 was converted to 6 in a
mixed solvent of methanol and dichloromethane or
chloroform even without heating if NaBPh4 was present.
Since a polar solvent is required, and NaBPh4 facilitates
the formation of complex 6 from complex 5, the
intermediate is likely ionic in nature and coordination
of the olefin double bond likely takes place after
dissociation of chloride rather than PPh3. Dissociation
of the chloride in complex 5 followed by coordination of
204.7 ppm with small coupling constants (2J(PC)ꢀ
6.1 Hz), indicating that the CO is cis to all the
phosphorus atoms. 1HÃ1H, 1HÃ13C and 13C DEPT
experiments suggest that the H signal of RuÃCH is at
2.7 ppm and the 13C signal of RuÃ
CH at 31.0 ppm. The
RuÃ
CH 13C signal has a large 2J(PC) coupling constant
/13.4,
/
/
1
/
/
/
(59.1 Hz), indicating that the alkyl is trans to a
phosphorus atom. The 31P{1H} NMR spectrum of
complex 6 (in C6D6) showed three signals at ꢂ
/
38.8,
the olefin double bond would give the hydridoÁ
/olefin
15.5 and 62.2 ppm. The signals at ꢂ
/
38.8 and 62.2 ppm
has a large 2J(PP) coupling constant (274.9 Hz),
suggesting that two of the phosphorus atoms are trans
complex
[RuH(CO)(PPh3)(Cy2PCH2CHÄ
/
CHCH2-
PCy2)]ꢁ. Insertion of the olefin double bond to the
Ru-H bond followed by addition of chloride would
produce complex 6.
1
to each others. A HÃ
/
31P COSY experiment indicates
that the two trans disposed phosphorus atoms are both
associated with the PCy2 groups. Considering the effect
of size of chelating ring on 31P chemical shifts [18], the
2.3. Synthesis of OsHCl(CO)(PPh3)(Cy2PCH2CHÄ
/
CHCH2PCy2)
signal at ꢂ38.8 ppm is assigned to the PCy2 group in the
/
four-membered ring and the signal at 62.2 ppm is
assigned to the PCy2 group in the five-membered ring.
The structure of 6 has been confirmed by an X-ray
diffraction study. The molecular geometry of 6 is
depicted in Fig. 1. The crystallographic details and
selected bond distances and angles are given in Tables 1
and 2 respectively. The X-ray diffraction study confirms
the structure deduced from the solution NMR data. The
We have tried to prepare the analogous osmium
complex OsHCl(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2)
by employing similar chemistry. Treatment of
OsHCl(CO)(PPh3)3 (9) with ligand
3
produced
(10)
OsHCl(CO)(PPh3)(Cy2PCH2CHÄCHCH2PCy2)
/
(Scheme 2), which can be isolated as a white solid in
approximately 55% yield after column chromatography
using 10% hexane in benzene as the eluent. Complex 10

S.H. Liu et al. / Inorganica Chimica Acta 334 (2002) 122Á
/130
125
Fig. 1. Molecular structure for RuCl(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2) (6). Hydrogen atoms on cyclohexyl and phenyl groups are omitted for
clarity.
1
has been characterized by H and 31P NMR spectro-
scopy and elemental analysis. In particular, the 1H
NMR spectrum (in C6D6) displayed the olefinic proton
Table 1
Crystal data and structure refinement for RuCl(CO)(PPh3)(Cy2PCH2-
CH(CH2)2PCy2) (6) and OsCl(H...H)(PPh3)(PCP) (12)
signal at 5.72 ppm and the hydride signal at ꢂ
/
7.26 ppm
2
(ddd, J(PH)ꢀ
/
82.7, 28.1, 24.0 Hz), the 31P{1H} NMR
spectrum showed three sets of doublet of doublets at
Complex 6
Complex 12
ꢂ
/
23.1, ꢂ3.6 and 3.8 ppm. We have tried to induce
/
Empirical formula
Formula weight
Crystal system
Space group
C47H66ClOP3Ru C50H44ClP3Os
876.43
triclinic
963.41
triclinic
insertion reaction by refluxing complex 10 in various
solvents. However, no reactions were observed.
¯
¯
P1/
/
P1/
/
˚
a (A)
10.463(4)
12.603(5)
17.970(9)
85.41(3)
81.86(3)
73.03(2)
2241.7(2)
2
17.1289(15)
19.6413(17)
21.1429(18)
111.676(2)
99.470(2)
101.255(2)
6260.8(9)
6
˚
2.4. Reaction of
RuCl(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2) with H2
b (A)
˚
c (A)
a (8)
b (8)
g (8)
V, (A )
Reaction of complex 6 with H2 in THF in the
presence of NaBPh4 gave the monohydride complex
RuHCl(CO)(PPh3)(Cy2P(CH2)4PCy2) (7). In refluxing
methanol, complex 6 reacted with H2 in the presence of
3
˚
Z
Dcalc (g cmꢂ3
)
1.298
0.71073
1.533
0.71073
˚
Radiation, Mo Ka (A)
u Range (8)
Reflection collected
NaBF4ÁK2CO3 to give the dihydride complex
/
2.00Á
/
23.99
1.07Á27.55
/
RuH2(CO)(PPh3)(Cy2P(CH2)4PCy2) (8). Thus the Ru-
alkyl bond in 6 has been cleaved in the reactions. The
structures of complexes 7 and 8 can be readily assigned
based on their NMR spectroscopic data.
6707
6291
42506
28352
Independent reflections
(Rintꢀ5.41%)
4047 (I ꢀ2s(I)) 19445 (I ꢀ2s(I))
(Rintꢀ15.43%)
Observed reflections
Number of parameter
refined
473
1486
Considering
MHCl(Et2PCH2CH2PEt2)2 (Mꢀ
the
fact
that
reactions
Fe, Ru, Os) with H2
of
/
Final R indices (I ꢀ2s(I))
Rꢀ6.57%,
wR2ꢀ13.42%
1.053
Rꢀ4.48%,
wR2ꢀ9.32%
0.904
in the presence of NaBPh4 give the corresponding
dihydrogen complexes [MH(H2)(Et2PCH2CH2PEt2)2]ꢁ
[17], a plausible mechanism for the formation of
complex 7 from the reaction of RuCl(CO)(PPh3)-
(Cy2PCH2CH(CH2)2PCy2) with H2 in the presence of
NaBPh4 is shown in Scheme 3. Reaction of complex 6
Goodness-of-fit
Largest difference peak
0.765
2.131
ꢂ3
˚
(e A
)
Largest difference hole
ꢂ0.577
ꢂ1.344
ꢂ3
˚
(e A
)

126
S.H. Liu et al. / Inorganica Chimica Acta 334 (2002) 122Á130
/
Table 2
˚
Selected bond distances (A) and angles (8) for RuCl(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2) (6)
Bond distances
Ru(1)ÃP(1)
Ru(1)ÃCl(1)
C(1)ÃC(2)
2.414(3)
2.476(2)
1.555(12)
1.112(9)
Ru(1)ÃP(2)
Ru(1)ÃC(2)
C(2)ÃC(3)
2.389(2)
2.145(8)
1.467(12)
Ru(1)ÃP(3)
Ru(1)ÃC(10)
C(3)ÃC(4)
2.487(2)
1.841(10)
1.508(12)
O(1)ÃC(10)
Bond angles
P(1)ÃRu(1)ÃP(2)
P(1)ÃRu(1)ÃC(2)
P(1)ÃRu(1)ÃCl(1)
P(2)ÃRu(1)ÃC(2)
P(2)ÃRu(1)ÃCl(1)
P(3)ÃRu(1)ÃC(10)
C(2)ÃRu(1)ÃC(10)
C(10)ÃRu(1)ÃCl(1)
Ru(1)ÃP(1)ÃC(1)
C(1)ÃC(2)ÃRu(1)
Ru(1)ÃC(2)ÃC(3)
C(3)ÃC(4)ÃP(2)
146.98(9)
65.7(2)
P(1)ÃRu(1)ÃP(3)
P(1)ÃRu(1)ÃC(10)
P(2)ÃRu(1)ÃP(3)
P(2)ÃRu(1)ÃC(10)
P(3)ÃRu(1)ÃC(2)
P(3)ÃRu(1)ÃCl(1)
C(2)ÃRu(1)ÃCl(1)
Ru(1)ÃC(10)ÃO(1)
P(1)ÃC(1)ÃC(2)
C(1)ÃC(2)ÃC(3)
C(2)ÃC(3)ÃC(4)
C(4)ÃP(2)ÃRu(1)
105.65(8)
89.1(3)
89.79(8)
81.3(2)
105.65(8)
89.5(3)
87.90(9)
93.5(3)
88.1(4)
172.8(2)
92.90(8)
85.6(3)
173.5(3)
85.7(3)
176.5(8)
93.7(6)
103.2(6)
115.5(6)
109.2(6)
118.0(8)
107.1(8)
99.4(3)
lead to an observable dihydrogen complex. However, we
have failed to isolate the expected monohydride complex
from the reactions of complex 6 with reagents such as
TlO2CH and NaBH4. The reactions usually lead to the
formation of the dihydride complex 8.
2.5. Synthesis of OsCl(H
/
Á Á Á
/
H)(PPh3)(PCP)
Iron group dihydrogen complexes of the type
MCl(alkyl)(H2)(L)3 have been proposed as the key
intermediates in catalytic hydrogenation reactions [6Á
/
8]. In order to prepare model complexes MCl(alk-
yl)(H2)(L)3, the reaction of H2 with the recently reported
complexes MCl(PPh3)(PCP) (Mꢀ
/
Ru [21g], Os [24];
Scheme 3.
PCPꢀ2,6-(Ph2PCH2)2C6H3) were investigated. Under
/
one atmosphere of H2, no reaction was observed
between H2 and RuCl(PPh3)(PCP). It is found that
OsCl(PPh3)(PCP) (11) readily picked up a H2 molecule
to give OsCl(H...H)(PPh3)(PCP) (12) which contains an
elongated h2-H2 moiety (Scheme 3). Several osmium
complexes containing PCP and related ligands have
been reported recently [13,24,25].
The structure of complex 12 can be readily assigned
by its NMR data. The 31P{1H} NMR spectrum in
CD2Cl2 showed a doublet at 14.8 ppm for the PPh2
with NaBPh4 could give the unsaturated intermediate
[Ru(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2)]BPh4 (A)
which can react with hydrogen to give the alkyl
dihydrogen complex [Ru(H2)(CO)(PPh3)(Cy2PCH2CH-
(CH2)2PCy2)]BPh4 (B). Proton transfer from the dihy-
drogen ligand to the a-carbon in B would produce
[RuH(CO)(PPh3)(Cy2P(CH2)4PCy2)]BPh4 (C) which
can pick up a chloride in the reaction mixture to give
complex 7.
With the hope to provide evidences for the reaction
sequences shown in Scheme 3, we have tried to generate
groups and a triplet at ꢂ1.0 ppm for the PPh3 ligand.
/
The 13C{1H} NMR spectrum in CD2Cl2 showed the
2
the
intermediate
[Ru(CO)(PPh3)(Cy2PCH2CH-
OsÃ
/
C signal at 159.0 ppm with a J(PC) coupling of
(CH2)2PCy2)]ꢁ by treating complex 6 with TlPF6 or
AgOTf. Unfortunately, no pure complexes could be
isolated from the reactions. In an alternative approach
to generate the dihydrogen complex [Ru(H2)(CO)-
(PPh3)(Cy2PCH2CH(CH2)2PCy2)]ꢁ, we have attempted
to prepare the hydride complex RuH(CO)(PPh3)-
(Cy2PCH2CH(CH2)2PCy2), hoping that subsequent pro-
tonation of the later complex at low temperature could
60.4 Hz. The magnitude of the 2J(PC) coupling constant
indicates that the PPh3 ligand is trans to the aryl group.
The existence of an elongated h2-H2 moiety in 12 is
supported by the variable temperature T1 measurements
and the observation of a J(HD) for the corresponding
isotopomer OsCl(H...D)(PPh3)(PCP). The 1H NMR
spectrum of 12 in CD2Cl2 showed the hydride signal
1
at ꢂ
/
10.83 ppm (dt, J(PH)ꢀ18.0, 9.0 Hz). A minimum
/

S.H. Liu et al. / Inorganica Chimica Acta 334 (2002) 122Á
/130
127
T1 value of 48 ms (300 MHz) was obtained for the
hydride signal at ꢂ10.83 ppm. Reaction of 11 in CD2Cl2
with HD gave the h2-HD isotopomer, OsCl(H
Á Á Á
D)(PPh3)(PCP), which showed a 1:1:1 triplet centered
at d ꢂ
10.89 ppm with 1J(HD)ꢀ9.0 Hz in the 1H NMR
spectrum. The HÃH distance in complex 12 is estimated
to be 1.27 A by use of the relationship d(HH)ꢀ
0.0167J(HD)ꢁ1.42 and J(HD)ꢀ9.0 Hz [26]. Several
/
/
/
/
/
/
˚
/
ꢂ
/
/
/
complexes containing elongated dihydrogen ligands
have been reported [27].
The structure of 12 has been confirmed by an X-ray
diffraction study. Crystals of 12 suitable for X-ray
diffraction were grown from a CH2Cl2 solution layered
with hexane. The crystallographic details and selected
bond distances and angles are given in Tables 1 and 3,
respectively. It is interesting to note that complex 12
crystallizes with three independent molecules devoid of
crystallographic symmetry in the asymmetric unit. The
three molecules are nearly the same and the molecular
geometry of one of them is depicted in Fig. 2. The metal-
bound hydrogen atoms in 12 could not be located, but
are presumably located at the vacant site trans to the
chloride. The solid state structure is consistent with the
NMR data in solution.
Fig. 2. Molecular structure for OsCl(H
gen atoms are omitted for clarity.
/
Á Á Á
/
H)(PPh3)(PCP) (12). Hydro-
hydride (CH2Cl2). The starting materials RuHCl(CO)-
(PPh3)3 [28], OsHCl(CO)(PPh3)3 [28], RuCl(PPh3)(PCP)
[21g], and OsCl(PPh3)(PCP) [24] were prepared accord-
ing to literature methods. All other reagents were used
as purchased from Aldrich. Microanalysis was per-
formed by M-H-W Laboratories (Phoenix, AZ, USA).
Mass spectra were recorded on a Finnigan TSQ7000
3. Experimental
1
spectrometer. H, 13C{1H} and 31P{1H} NMR spectra
All manipulations were carried out under a nitrogen
atmosphere using standard Schlenk techniques. Solvent
were distilled under dinitrogen from sodium-benzophe-
none (hexane, diethyl ether, THF, benzene) and calcium
1
were collected on a Bruker ARX-300 spectrometer. H
and 13C chemical shifts are relative to TMS, and 31P
NMR chemical shifts are relative to 85% H3PO4.
Table 3
Selected bond distances (A) and angles (8) for OsCl(H
˚
/
Á Á Á
/
H)(PPh3)(PCP) (12)
Bond distances
Os(1)ÃP(11)
Os(1)ÃP(12)
Os(1)ÃP(13)
Os(1)ÃCl(11)
Os(1)ÃC(101)
2.3553(13)
2.3307(13)
2.4126(15)
2.4972(14)
2.142(5)
Os(2)ÃP(21)
Os(2)ÃP(22)
Os(2)ÃP(23)
Os(2)ÃCl(2)
Os(2)ÃC(201)
2.3379(13)
2.3437(13)
2.4096(14)
2.4783(13)
2.149(5)
Os(3)ÃP(31)
Os(3)ÃP(32)
Os(3)ÃP(33)
Os(3)ÃCl(3)
Os(3)ÃC(301)
2.3433(13)
2.3478(13)
2.4002(14)
2.4742(14)
2.146(5)
Bond angles
C(101)ÃOs(1)ÃP(12)
C(101)ÃOs(1)ÃP(11)
C(101)ÃOs(1)ÃP(13)
C(101)ÃOs(1)ÃCl(1)
P(11)ÃOs(1)ÃP(13)
P(11)ÃOs(1)ÃCl(1)
P(12)ÃOs(1)ÃP(11)
P(12)ÃOs(1)ÃP(13)
P(12)ÃOs(1)ÃCl(1)
P(13)ÃOs(1)ÃCl(1)
C(301)ÃOs(3)ÃP(31)
C(301)ÃOs(3)ÃP(33)
P(31)ÃOs(3)ÃP(32)
P(31)ÃOs(3)ÃCl(3)
P(32)ÃOs(3)ÃCl(3)
78.84(14)
79.37(14)
174.16(14)
85.84(14)
98.82(5)
C(201)ÃOs(2)ÃP(21)
C(201)ÃOs(2)ÃP(22)
C(201)ÃOs(2)ÃP(23)
C(201)ÃOs(2)ÃCl(2)
P(21)ÃOs(2)ÃP(23)
P(21)ÃOs(2)ÃCl(2)
P(21)ÃOs(2)ÃP(22)
P(21)ÃOs(2)ÃP(23)
P(21)ÃOs(2)ÃCl(2)
P(23)ÃOs(2)ÃCl(2)
C(301)ÃOs(3)ÃP(32)
C(301)ÃOs(3)ÃCl(3)
P(31)ÃOs(3)ÃP(33)
P(32)ÃOs(3)ÃP(33)
P(33)ÃOs(3)ÃCl(3)
79.15(14)
79.35(14)
175.33(13)
85.29(13)
101.15(5)
87.12(5)
99.45(5)
156.89(5)
103.60(5)
86.57(5)
158.40(5)
100.44(5)
93.23(5)
89.01(5)
90.09(5)
77.27(14)
86.23(5)
78.56(14)
175.35(14)
155.79(5)
87.64(5)
101.87(5)
102.33(5)
89.16(5)
92.05(5)

128
S.H. Liu et al. / Inorganica Chimica Acta 334 (2002) 122Á130
/
3.1. [Cis-Cy2HPCH2CHÄ
/
CHCH2PHCy2]I2 (2)
2H, Ä
(75.47 MHz, C6D6): d 1.0Á
127.4Á139.0 (m, ÄCH, Ph), 204.0 (td, J(PC)ꢀ
Hz, Ru(CO)). 31P{1H} NMR (121.49 MHz, C6D6): d
6.1 (t, J(PP)ꢀ17.8 Hz, PCy2), 33.0 (dd, J(PP)ꢀ274.5,
19.0 Hz, PPh3), 37.4 (dd, J(PP)ꢀ274.5, 16.6 Hz, PCy2).
/
CH), 7.37Á
/
7.80 (m, 15H, PPh3). 13C{1H} NMR
53.1 (m, Cy, ÄCHCH2),
13.5, 8.5
/
/
A mixture of cis-ClCH2CHÄ
/CHCH2Cl (3.01 g, 24.1
/
/
/
mmol), KI (8.2 g, 49 mmol) and HPCy2 (21.0 ml, 70.6
mmol) in dried acetone (220 ml) was refluxed for 3 h. A
large amount of white precipitate was formed. The white
precipitate was collected on a filter frit and washed with
/
/
/
acetone (3ꢃ
/
50 ml), diethyl ether (3ꢃ/70 ml) and 1:1
3.4. RuCl(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2) (6)
methanolÁwater, and dried under vacuum. Yield: 14.0
/
g, 59.7%. Anal. Calc. for C28H50I2P2: C, 47.88; H, 7.17.
Found: C, 47.45; H, 7.40. 1H NMR (300.13 MHz,
A
solution of RuHCl(CO)(PPh3)(Cy2PCH2CHÄ
/
CHCH2PCy2) (1.21 g, 1.38 mmol) in 1:1 methanolÁ
/
CD3OD): d 1.47Á
4H, CH of Cy), 3.61 (m, board, 4H, CH2PCy2), 6.05 (m,
2H, ÄCH). The signal of PH could not be observed in
CD3OD because of H/D exchange. 13C{1H} NMR
(75.47 MHz, CD3OD): d 14.4Á28.5 (m, CH2PCy2),
123.9 (dd, J(PC)ꢀ12.2, 8.2 Hz, Ä
CH). 31P{1H} NMR
(121.49 MHz, CD3OD): d 24.4. FAB MS: m/z (relative
intensity) 449 (20) ([Cy2HPCH2CHÄ
CHCH2PCy2]ꢁ),
251 (100) ([Cy2PCH2CHÄ
CHCH2]ꢁ).
/
2.16 (m, 40H, CH2 of Cy), 2.85 (m,
dichloromethane (40 ml) was refluxed for 8 h. The
solvents were removed under vacuum. Methanol (30 ml)
was added to the residue and the mixture was stirred for
30 min to give a white precipitate. The precipitate was
collected on a filter frit, washed with methanol and dried
under vacuum. The product was further purified by re-
/
/
/
/
crystallization from benzeneÁmethanol. Yield: 0.77 g,
/
/
64%. Anal. Calc. for C47H66ClOP3Ru: C, 64.41; H, 7.59.
Found: C, 64.60; H, 7.43. 1H NMR (300.13 MHz,
/
C6D6):
Cy2)CH2CH2PCy2), 7.13Á
13C{1H} NMR (75.47 MHz, CDCl3): d 25.9Á
RuCH(CH2PCy2)CH2CH2PCy2), 127.3Á139.7 (m,
PPh3), 204.7 (td, J(PC)ꢀ13.4, 6.1 Hz, Ru(CO)).
COSY experiments shows that the RuÃ
CH 13C signal
is at d 31.0 (dd, J(PC)ꢀ
5 9.1, 23.3 Hz). 31P{1H} NMR
(121.49 MHz, C6H6): d ꢂ38.8 (dd, J(PP)ꢀ274.9, 13.7
Hz, PCy2), 15.5 (dd, J(PP)ꢀ13.7, 4.9 Hz, PPh3), 62.2
(dd, J(PP)ꢀ274.9, 4.9 Hz, PCy2).
d
1.14Á
/
3.67 (m, 51H, RuCH(CH2P-
8.19 (m, 15H, PPh3).
38.4 (m,
3.2. Cis-Cy2PCH2CHÄ
/
CHCH2PCy2 (3)
/
/
A
suspension of [cis-Cy2HPCH2CHÄ
/CHCH2-
/
PHCy2]I2 (10.39 g, 14.75 mmol) in diethyl ether (70
ml) was treated with NaOH (2.20 g, 55.0 mmol) in water
(40 ml). After the mixture was stirred for 5 h, the organic
layer was separated and dried with MgSO4. The solution
was filtered and the solvent was removed under vacuum
to give a pale yellow viscous liquid. Yield: 6.24 g, 94.3%.
/
/
/
/
/
/
/
1H NMR (300.13 MHz, C6D6): d 1.28Á
Cy), 2.55 (m, 4H, CH2PCy2), 5.83 (m, 2H, Ä
13C{1H} NMR (75.47 MHz, C6D6): d 21.1Á
33.7 (m,
CH2PCy2), 127.1 (t, J(PC)ꢀ9.7 Hz, Ä
CH). 31P{1H}
NMR (121.49 MHz, C6D6): d ꢂ3.9 (s).
/
2.01 (m, 44H,
CH),
/
3.5. Reaction of
RuCl(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2) with H2
/
/
/
/
A
mixture of RuCl(CO)(PPh3)(Cy2PCH2CH-
(CH2)2PCy2) (0.2 g, 0.228 mmol), NaBPh4 (0.45 g,
1.31 mmol) and 30 ml of THF was stirred under H2
atmosphere for 20 h. An in situ 31P[1H} NMR shows
that all the starting material has converted to
RuHCl(CO)(PPh3)(Cy2P(CH2)4PCy2). The solvent was
removed completely under vacuum. Forty milliliters of
hexane was added to the residue and the mixture was
stirred for 1 h. The solution was filtered through a
column of celite. The solvent of the filtrate was removed
3.3. RuHCl(CO)(PPh3)(Cy2PCH2CHÄ
/
CHCH2PCy2)
(5)
A mixture of RuHCl(CO)(PPh3)3 (2.14 g, 2.25 mmol)
and cis-Cy2PCH2CHÄCHCH2PCy2 (0.95 g, 2.1 mmol)
/
in benzene (30 ml) was refluxed for 30 min. The solvent
was removed completely under vacuum. Fifty milliliters
of hexane was added and the mixture was stirred for 0.5
h. The solution was filtered through a column of celite
to remove the unreacted RuHCl(CO)(PPh3)3. The
solvent was removed under vacuum to give an oily
residue. Methanol (50 ml) was added to the residue and
the mixture was stirred for 3 h to give a white
precipitate. The white solid was collected on a filter
frit and washed with methanol and dried under vacuum.
Yield: 1.12 g, 60.6%. Anal. Calc. for C47H66ClOP3Ru:
1
under vacuum. Yield, 0.11 g, 55%. H NMR (300.13
MHz, CD2Cl2): d ꢂ
Hz, 1H, RuH), 1.24Á
7.35- 7.48 (m, PPh3). 31P{1H} NMR (121.49 MHz,
CD2Cl2): d 17.8 (t, J(PP)ꢀ14.5 Hz, PPh3), 33.2 (dd,
J(PP)ꢀ275.5, 13.9 Hz), 36.2 (dd, J(PP)ꢀ276.5, 15.4
Hz).
/
7.49 (ddd, J(PH)ꢀ/103.2, 25.5, 22.5
/2.11 (m, 52H, Cy2P(CH2)4PCy2),
/
/
/
1
C, 64.41; H, 7.59. Found: C, 64.60. H, 7.59. H NMR
3.6. RuH2(CO)(PPh3)(Cy2P(CH2)4PCy2) (8)
(300.13 MHz, C6D6): d ꢂ
27.9, 23.6 Hz, 1H, RuH), 1.36Á
CHCH2), 3.78 (m, board, 2H, ÄCHCH2), 5.87 (s, board,
/
7.15 (ddd, J(PH)ꢀ
/
102.8,
/
2.76 (m, 46H, Cy, Ä
/
A mixture of RuCl(CO)(PPh3)(Cy2PCH2CH-
(CH2)2PCy2) (0.25 g, 0.29 mmol), NaBF4 (1.0 g, 9.1
/

S.H. Liu et al. / Inorganica Chimica Acta 334 (2002) 122Á
/130
129
mmol) and K2CO3 (1.0 g, 7.24 mmol) and 60 ml of
MeOH (degassed) was refluxed under H2 for 16 h. The
solvent was removed completely under vacuum. The
residue was extracted with 60 ml of benzene. The
benzene solution was filtered through a column of celite.
The filtrate was concentrated to dryness to give a white
300.13 MHz, CD2Cl2]: 68.0 (298 K), 54.3 (280 K), 50.4
(270 K), 49.3 (265 K), 48.4 (260 K), 48.4 (250 K), 50.8
(240 K), 56.1 (230 K), 68.2 (220 K).
3.9. OsCl(H/
Á Á Á
/
D)(PPh3)(PPh3)(PCP) (12d1)
solid. Yield: 0.18 g, 75%. Anal. Calc. for C47H69OP3Ru×
1.5 C6H6: C, 69.98; H, 8.18. Found: C, 70.19; H, 7.49.
31P{1H} NMR (CD2Cl2, 121.5 MHz): d 48.1 (dd,
/
The complex was prepared by the same procedure as
for 12 with the use of HD instead of H2. 1H{31P} NMR
(300.13 MHz, CD2Cl2, 298 K): d ꢂ
/
10.89 (t, J(HD)ꢀ
/
J(PP)ꢀ
(dd, J(PP)ꢀ
MHz): d ꢂ8.23 (dtd, J(PH)ꢀ
6.0 Hz, 1H, RuH), ꢂ9.65 (dddd, J(PH)ꢀ
26.1 Hz, J(HH)ꢀ5.7 Hz, RuH), 1.38-2.36 (m, 52H,
Cy2P(CH2)4PCy2), 7.2ꢂ8.2 (m, 15H, PPh3).
/
219.7, 16.9 Hz), 51.9 (t, J(PP)ꢀ
219.7, 13.8 Hz). 1H NMR (CD2Cl2, 300.13
28.2, 21.8 Hz, J(HH)ꢀ
68.7, 31.2,
/
15.1 Hz), 61.7
9.0 Hz, Os(HD)).
/
/
/
/
3.10. Crystallographic details for
/
/
RuCl(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2) (6)
/
/
Crystals suitable for X-ray diffraction (XRD) were
grown from methanol. A crystal with approximate
3.7. OsHCl(CO)(PPh3)(Cy2PCH2CHÄ
/
CHCH2PCy2)
dimensions of 0.20ꢃ
a glass fiber for diffraction experiment. Intensity data
/
0.10ꢃ0.05 mm was mounted on
/
(10)
were collected on a Siemens P4-RA diffractometer with
˚
0.71073 A) and graphite mono-
A mixture of OsHCl(CO)(PPh3)3 (0.99 g, 0.95 mmol)
and cis-Cy2PCH2CHÄCHCH2PCy2 (0.34 g, 0.76 mmol)
Mo Ka radiation (lꢀ
/
/
chromator using v scan mode. A semi-empirical absorp-
tion correction (psi) was applied with transmission
factors from 0.853 to 0.929 on I. The structure was
solved by direct method and refined by full-matrix least-
squares on F2 using Bruker SHELXTL (Version 5.10)
program package [29]. All non-H atoms were refined
anisotropically. The H atoms were placed in the ideal
positions and refined as riding atoms. Further crystal
data and details of the data collection are summarized in
Table 1. Selected bond distances and angles are given in
Table 2.
in benzene (30 ml) was stirred at 50 8C for 2 h. The
volume of the reaction mixture was reduced to approxi-
mately 3 ml. The product was purified by chromato-
graphy on silica gel column eluted with 10% hexane in
benzene. Yield: 0.41 g, 55%. Anal. Calc. for C47H66ClO-
1
P3Os: C, 58.46; H, 6.89. Found: C, 58.60; H, 6.87. H
NMR (300.13 MHz, C6D6): d ꢂ
82.7, 28.1, 24.0 Hz, 1H, OsH), 1.00Á
CHCH2), 3.52 (m, board, 2H, ÄCHCH2), 5.72 (s,
broad, 2H, Ä
CH), 6.89-8.08 (m, 15H, PPh3). 31P{1H}
NMR (121.49 MHz, C6D6): d ꢂ23.1 (t, J(PP)ꢀ13.9
Hz), ꢂ3.6 (dd, J(PP)ꢀ250.6, 12.7 Hz), 3.8 (dd,
J(PP)ꢀ250.6, 15.1 Hz).
/
7.26 (ddd, J(PH)ꢀ
/
/
2.70 (m, 46H, Cy,
Ä
/
/
/
/
/
/
/
3.11. Crystallographic detail for
/
OsCl(H
/
Á Á Á
/
H)(PPh3)(PCP) (12)
3.8. OsCl(H
/
Á Á Á
/
H)(PPh3)(PCP) (12)
Crystals suitable for XRD were grown from a CH2Cl2
solution layered with hexane. A colorless plate single
A CH2Cl2 (20 ml) solution of OsCl(PPh3)(PCP) (0.3 g,
0.31 mmol) in a Schlenk flask was attached to a H2
balloon. The reaction mixture was stirred at room
temperature (r.t.) for 20 min to give a pink solution.
The solvent was evaporated to dryness under vacuum. A
pink solid was formed when ether (20 ml) was added.
The solid was collected by filtration, washed with ether
crystal with approximate dimensions of 0.18ꢃ
/
0.08ꢃ
/
0.06 mm was mounted in a glass capillary for diffraction
experiment. Intensity data were collected on a Bruker
SMART CCD Area Detector and corrected for SADABS
(Siemens Area Detector Absorption) [30] (from 0.5211
to 0.9365 on I). The structure was solved by direct
methods, expanded by difference Fourier syntheses and
refined by full-matrix least-squares on F2 using Bruker
SHELXTL (Version 5.10) program package [29]. The
asymmetric unit of this structure contains three inde-
(2ꢃ15 ml) and dried under vacuum overnight. Yield:
/
0.26 g, 87%. Anal. Calc. for C50H44P3ClOs: C, 62.33; H,
4.60. Found: C, 62.12; H, 4.72. 31P{1H} NMR (121.5
MHz, CD2Cl2): d 14.8 (d, J(PP)ꢀ
/
13.3 Hz), ꢂ
13.3 Hz). H NMR (300.13 MHz, CD2Cl2): d
10.83 (dt, J(PH)ꢀ18.0, 9.0 Hz, 2H, OsH2), 3.82 (dt,
J(HH)ꢀ15.6 Hz, J(PH)ꢀ4.3 Hz, 2H, CH2), 4.89 (dt,
J(HH)ꢀ15.6 Hz, J(PH)ꢀ3.9 Hz, 2H, CH2), 7.48Á6.96
(m, 38H, PPh3, PPh2, C6H3). 13C{1H} NMR (75.47
MHz, CD2Cl2): d 159.0 (d, J(PC)ꢀ60.4 Hz, OsÃ
C(aryl)), 146.9ꢂ121.8 (m, other aromatic C), 50.6 (td,
J(PC)ꢀ19.0, 5.4 Hz, PCPÃCH2). T1 [ms, Os(H2),
/
1.0 (t,
pendent OsCl(H
/
Á Á Á
/
H)(PPh3)(PCP) molecules. All non-H
1
J(PP)ꢀ
/
atoms were refined anisotropically. The hydrogen atoms
were placed in the ideal positions and refined as riding
atoms. Attempts to locate the metal-bound H atoms
were unsuccessful. A final difference Fourier was
essentially featureless with largest peak being 2.131
ꢂ
/
/
/
/
/
/
/
ꢂ3
˚
eA
details of the data collection are summarized in Table 1.
/
/
at the osmium site. Further crystal data and
/
/
/
Selected bond distances and angles are given in Table 3.

130
S.H. Liu et al. / Inorganica Chimica Acta 334 (2002) 122Á130
/
(c) A.C. Albeniz, G. Schulte, R.H. Crabtree, Organometallics 11
(1992) 242.
4. Supplementary material
[13] D.G. Guesev, F.M. Dolgushin, M.Y. Antipin, Organometallics 20
(2001) 1001.
Tables of crystallographic details, bond distances and
angles, atomic coordinates and equivalent isotropic
displace coefficients, anisotropic displacement coeffi-
cients for RuCl(CO)(PPh3)(Cy2PCH2CH(CH2)2PCy2)
[14] J.N. Coalter, III, J.C. Huffman, K.G. Caulton, Organometallics
19 (2000) 3569.
[15] C. Crocker, R.J. Errington, R. Markham, C.J. Moulton, K.J.
Odell, B.L. Shaw, J. Am. Chem. Soc. 102 (1980) 4373.
[16] (a) C.J. Moulton, B.L. Shaw, J. Chem. Soc., Dalton Trans. (1976)
1020.;
(6) and OsCl(H
/
Á Á Á
/
H)(PPh3)(PCP) (12). Crystallographic
data for the structures reported in this paper have been
deposited with the Cambridge Crystallographic Data
center as publication nos. CCDC 173451 (6) and 173495
(12). Copies of the data can be obtained free of charge
on application to CCDC, 12 Union Road, Cambridge
(b) A.R. Kennedy, R.J. Cross, K.W. Muir, Inorg. Chim. Acta 231
(1995) 195.
[17] (a) M.T. Bautista, E.P. Cappellani, S.D. Drouin, R.H. Morris,
C.T. Schweitzer, A. Sella, J. Zubkowski, J. Am. Chem. Soc. 113
(1991) 4876;
CB2 1EZ, UK (fax: ꢁ44-1223-336-033; e-mail: depos-
/
(b) K.A. Earl, G. Jia, P.A. Maltby, R.H. Morris, J. Am. Chem.
Soc. 113 (1991) 3027.
it@ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk.
[18] P.E. Garrou, Chem. Rev. 81 (1981) 229.
[19] D. Huang, J.C. Bollinger, W.E. Streib, K. Folting, V. Young, Jr.,
O. Eisenstein, K.G. Caulton, Organometallics 19 (2000) 2281.
[20] M. Shiotsuki, T. Suzuki, T. Kondo, K. Wada, T. Mitsudo,
Organometallics 19 (2000) 5733.
Acknowledgements
The authors acknowledge financial support from the
Hong Kong Research Grants Council.
[21] See for example,
(a) P. Dani, B. Richter, G.P.M. van Klink, G. van Koten, Eur. J.
Inorg. Chem. (2001) 125.
(b) P. Dani, M.A.M. Toorneman, G.P.M. van Klink, G. van
Koten, Organometallics 19 (2000) 5287.
References
(c) P. Dani, M. Albrecht, G.P.M. van Klink, G. van Koten,
Organometallics 19 (2000) 4468.
[1] G.J. Kubas, R.R. Ryan, B.I. Swanson, P.J. Vergamini, H.J.
Wasserman, J. Am. Chem. Soc. 106 (1984) 451.
(d) D.G. Gusev, F.M. Dolgushin, M. Yu, Antipin, Organome-
tallics 19 (2000) 3429.
[2] (a) R.H. Crabtree, Angew. Chem., Int. Ed. Engl. 32 (1993) 789;
(b) D.M. Heinekey, W.J. Oldham, Jr., Chem. Rev. 93 (1993) 913;
(c) P.G. Jessop, R.H. Morris, Coord. Chem. Rev. 121 (1992) 155.
[3] M.A. Esteruelas, L.A. Oro, Chem. Rev. 98 (1998) 577.
[4] Y. Nishibayashi, I. Takei, M. Hidai, Angew. Chem., Int. Ed.
Engl. 38 (1999) 3047.
(e) D.G. Gusev, M. Madott, F.M. Dolgushin, K.A. Lyssenko,
M.Y. Antipin, Organometallics 19 (2000) 1734.
(f) M.E. van der Boom, H.B. Kraatz, L. Hassner, Y. Ben-David,
D. Milstein, Organometallics 18 (1999) 3873.
(g) G. Jia, H.M. Lee, H.P. Xia, I.D. Williams, Organometallics 15
(1996) 5453.
[5] (a) C. Bianchini, A. Meli, M. Peruzzini, P. Frediani, C. Bohanna,
M.A. Esteruelas, L.A. Oro, Organometallics 11 (1992) 138;
(b) C. Bianchini, C. Bohanna, M.A. Esteruelas, P. Frediani, A.
Meli, L.A. Oro, M. Peruzzini, Organometallics 11 (1992) 3837.
[6] (a) A. Andriollo, M.A. Esteruelas, U. Meyer, L.A. Oro, R.A.
Sa´nchez-Delgado, E. Sola, C. Valero, H. Werner, J. Am. Chem.
Soc. 111 (1989) 7431;
[22] (a) M.A. Bennett, R.N. Johnson, I.B. Tomkins, Inorg. Chem. 14
(1975) 1908;
(b) M.A. Bennett, R.N. Johnson, I.B. Tomkins, J. Am. Chem.
Soc. 96 (1974) 61.
[23] R.H. Crabtree, The Organometallic Chemistry of Transition
Metals, second ed., Wiley, New York, 1994, p. 168.
[24] T.B. Wen, Y.K. Cheung, J. Yao, W.T. Wong, Z.Y. Zhou, G. Jia,
Organometallics 19 (2000) 3803.
(b) M.A. Esteruelas, L.A. Oro, C. Valero, Organometallics 11
(1992) 3362.
[25] R.M. Gauvin, H. Rozenberg, L.J.W. Shimon, D. Milstein,
Organometallics 20 (2001) 1719.
[7] R.H. Crabtree, The Organometallic Chemistry of the Transition
Metals, second ed., Wiley, New York, 1994, p. 221.
[8] W.C. Chan, C.P. Lau, Y.Z. Chen, Y.Q. Fang, S.M. Ng, G. Jia,
Organometallics 16 (1997) 34.
[26] P.A. Maltby, M. Schlaf, M. Steinbeck, A.J. Lough, R.H. Morris,
W.T. Klooster, T.F. Koetzle, R.C. Srivastava, J. Am. Chem. Soc.
118 (1996) 5396.
[9] M.J. Tenorio, M.C. Puerta, P. Valerga, J. Chem. Soc., Chem.
Commun. (1993) 1750.
[27] R. Castarlenas, M.A. Esteruelas, E. Gutie´rrez-Puebla, Y. Jean, A.
Lledo´s, M. Mart´ın, J. Toma´s, Organometallics 18 (1999) 4296
(and references therein).
[10] J. Espuelas, M.A. Esteruelas, F.J. Lahoz, L.A. Oro, C. Valero,
Organometallics 12 (1993) 663.
[11] G. Barea, M.A. Esteruelas, A. Lledo´s, A.M. Lo´pez, E. Onate, J.I.
˜
[28] N. Ahmad, J.J. Levison, S.D. Robinson, M.F. Uttley, Inorg.
Synth. 15 (1974) 45.
TM
[29] Bruker, SHELXTL
Tolosa, Organometallics 17 (1998) 4065.
[12] (a) R.H. Crabtree, M. Lavin, L. Bonneviot, J. Am. Chem. Soc.
108 (1986) 4032;
Reference Manual (Version 5.1), Bruker
Analytical X-Ray Systems Inc., Madison, WI, USA, 1997.
[30] G.M. Sheldrick, SADABS Empirical Absorption Correction
Program, University of Gottingen, Germany, 1996.
,
(b) A.C. Albeniz, D.M. Heinekey, R.H. Crabtree, Inorg. Chem.
30 (1991) 3632;
¨