Synthesis and reactions of heterodinuclear organopalladium complex having an unsymmetrical PN ligand

Article abstract of DOI:10.1016/j.jorganchem.2007.04.029

Novel heterodinuclear organopalladium complexes having an unsymmetrical PN ligand (Et₂NC₂H₄PPh₂-κ²N,P)RPd-ML_n (ML_n = Co(CO)₄; R = Me (2a), Ph (2b), ML_n = MoCp(CO)₃; R = Ph (3b)) are synthesized by metathetical reactions of PdRX(Et₂NC₂H₄PPh₂-κ²N,P) (X = I, NO₃) with Na⁺[ML_n]^-. Reversible dissociation of the Pd-N bond in 3b is revealed by variable temperature NMR studies. Reactions of 2a and 2b with CO yield corresponding acyl complexes (Et₂NC₂H₄PPh₂-κ²N,P)(RCO)Pd-Co(CO)₄ (R = Me (5a), Ph (5b)). Rate of CO insertion for 2a and 2b is significantly faster than those for mononuclear methylpalladium complex, PdMeI(Et₂NC₂H₄PPh₂-κ²N,P) (1a), and methylpalladium-cobalt complex with a 1,2-bis(diphenylphosphino)ethane (dppe) ligand, (dppe-κ²P,P′)MePd-Co(CO)₄ (6a). 5a smoothly reacts with nucleophiles such as diethylamine, methanol and benzenethiol to give corresponding amide, ester and thioester, respectively. These reactions of 5a are also significantly faster than those of corresponding mononuclear analogues and the similar heterodinuclear complexes with symmetrical bidentate ligands such as 1,2-bis(diphenylphosphino)ethane or N,N,N′,N′-tetramethylethylenediamine ligand.

Full text of DOI:10.1016/j.jorganchem.2007.04.029

Journal of Organometallic Chemistry 692 (2007) 4486–4494
www.elsevier.com/locate/jorganchem
Synthesis and reactions of heterodinuclear organopalladium
complex having an unsymmetrical PN ligand
*
Nobuyuki Komine, Susumu Tsutsuminai, Masafumi Hirano, Sanshiro Komiya
Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho,
Koganei, Tokyo 184-8588, Japan
Received 1 February 2007; received in revised form 20 April 2007; accepted 20 April 2007
Available online 25 April 2007
This paper is dedicated to Prof. Dr. Gerhard Erker on the occasion of his 60th birthday.
Abstract
Novel heterodinuclear organopalladium complexes having an unsymmetrical PN ligand (Et2NC2H4PPh2-j2N,P)RPd–MLn
(MLn = Co(CO)4; R = Me (2a), Ph (2b), MLn = MoCp(CO)3; R = Ph (3b)) are synthesized by metathetical reactions of
PdRX(Et2NC2H4PPh2-j2N,P) (X = I, NO3) with Na+[MLn]ꢀ. Reversible dissociation of the Pd–N bond in 3b is revealed by variable
temperature NMR studies. Reactions of 2a and 2b with CO yield corresponding acyl complexes (Et2NC2H4PPh2-j2N,P)(RCO)Pd–
Co(CO)4 (R = Me (5a), Ph (5b)). Rate of CO insertion for 2a and 2b is significantly faster than those for mononuclear methylpalladium
complex, PdMeI(Et2NC2H4PPh2-j2N,P) (1a), and methylpalladium–cobalt complex with a 1,2-bis(diphenylphosphino)ethane (dppe)
ligand, (dppe-j2P,P0)MePd–Co(CO)4 (6a). 5a smoothly reacts with nucleophiles such as diethylamine, methanol and benzenethiol to give
corresponding amide, ester and thioester, respectively. These reactions of 5a are also significantly faster than those of corresponding
mononuclear analogues and the similar heterodinuclear complexes with symmetrical bidentate ligands such as 1,2-bis(diphenylphosph-
ino)ethane or N,N,N0,N0-tetramethylethylenediamine ligand.
ꢀ 2007 Elsevier B.V. All rights reserved.
Keywords: Heterodunuclear organopalladium complex; Unsymmetrical PN ligand; CO insertion
1. Introduction
[2a,2c,2d,2h,2k,2o], significant acceleration of b-H elimina-
tion [2f,2i], and enhanced CO insertion reactions [2g,2l]. On
the other hand, introduction of an unsymmetrical PN
ligand into organometallic complex is expected to give
higher selectivity and activity, because PN chelating ligand
may provide a preferential vacant coordination site on
metal center due to facile dissociation of the nitrogen atom.
We recently reported synthesis of hetrodinuclear
organoplatinum complex having a hemilabile ligand and
reactions of heterodinuclear methylplatinum–molybdenum
derivative, (Et2NC2H4PPh2-j2N,P)MePt–MoCp(CO)3 with
dimethyl acetylenedicarboxylate to give novel l-platinacyc-
lobutenone complexes (Et2NC2H4PPh2-j2N,P)MePt{l-
g2:g2-C(O)C2(CO2Me)2}MoCp(l-CO)(CO) [3]. In this
work, we investigated the synthesis and reactions of novel
heterodinuclear organopalladium complexes having an
unsymmetrical PN ligand.
Heterodinuclear organometallic complexes are expected
to show cooperative effects of different metal centers [1].
We previously reported synthesis of hetrodinuclear organo-
platinum or -palladium complexes with a symmetrical
bidentate ligand such as 1,5-cyclooctadiene (cod), 1,2-bis-
(diphenylphosphino)ethane (dppe), N,N,N0,N0-tetramethy-
lethylenediamine (tmeda), 2,20-bipyridine (bpy), and 1,10-
phenanthroline (phen), L2RM–M0L0n (M = Pt, Pd;
M0 = Mo, W, Mn, Re, Fe, Co; R = Me, Et, CH2CMe3,
Ph, COMe, COPh, H; L2 = cod, dppe, tmeda, bpy, phen;
L0 = CO, Cp) [2]. They show unique reactions such as
organic group transfer between different metal centers
*
Corresponding author.
E-mail address: komiya@cc.tuat.ac.jp (S. Komiya).
0022-328X/$ - see front matter ꢀ 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2007.04.029

N. Komine et al. / Journal of Organometallic Chemistry 692 (2007) 4486–4494
4487
2. Results and discussion
Table 1. The molecular structure of 1a was determined
by single crystal X-ray structure analysis, and the
ORTEP drawing of 1a is depicted in Fig. 1. The
31P{1H} NMR spectrum of 1a shows a singlet at d
42.4. In the 1H NMR of 1a, the methylene protons of
the NCH2CH3 moiety appear as two doublets of quartets
at d 3.05 and 3.40, indicating that these methylene pro-
tons are diastereotopic. This fact is an indication of rigid
coordination of both nitrogen and phosphorus atoms to
the Pd center. The Pd–Me resonance is observed at d
2.1. Synthesis of hetetrodinucular organopalladium–cobalt
(or –molybdenum) complexes
A series of novel heterodinuclear organopalladium–
cobalt (or –molybdenum) complexes having an unsym-
metrical PN ligand were prepared by the metathetical
reaction of PdRX(Et2NC2H4PPh2-j2N,P) (R = Me, Ph;
X = I, NO3) with corresponding carbonyl metallates such
as Na+[MoCp(CO)3]ꢀ [4] and Na+[Co(CO)4]ꢀ [5]. Start-
ing complexes PdRI(Et2NC2H4PPh2-j2N,P) (R = Me
(1a), Ph (1b)) were prepared by the oxidative addition
of methyl or phenyl iodide to Pd2(dba)3 Æ CHCl3 [6]
(dba = dibenzylideneacetone) in the presence of 2-(diph-
enylphosphino)triethylamine [7] in 46% and 14% yield,
respectively (Eq. (1)). These novel organopalladium com-
plexes having an unsymmetrical PN ligand (1a,b) were
characterized by NMR and IR spectroscopies and ele-
mental analysis. Selected IR and NMR data of newly
prepared compounds, 1a and 1b, are summarized in
3
0.65 as a doublet with a small JPH value 3.9 Hz, suggest-
ing that the Me ligand locates in the cis position to the
phosphorus atom. This structural feature may be due to
difference of relative trans influence of the coordinating
atoms, where ligands having strong trans influence (Me
and P) disfavor mutually trans positions to each other.
Thus, the starting complex PdMeI(Et2NC2H4PPh2-
j2N,P) (1a) in solution as well as in solid state has a
square planar geometry depicted in Eq. (1). Analogous
spectroscopic data are also obtained for PdPhI-
(Et2NC2H4PPh2-j2N,P) (1b).
Table 1
Selected IR and NMR data of mononuclear palladium complex, PdRI(Et2NC2H4PPh2-j2N,P) and heterodinuclear organopalladium–cobalt(or –
molybdenum) complexes, (Et2NC2H4PPh2-j2N,P)RPd–MLn (MLn = Co(CO)4, MoCp(CO)3)
Complex IR (mCO, cmꢀ1 a
)
1H NMR (ppm, rt)
31P NMR (ppm, rt)
R
NCH2CH3
3
3
1ab
1bc
2ad
2bd
0.65 (d, JPH = 3.9 Hz, 3H, CH3)
1.20 (t, JHH = 7.2 Hz, 6H, NCH2CH3)
42.4 (s)
2
3
3.05 (dq, JHH = 13.0 Hz, JHH = 7.2 Hz, 2H, NCH2CH3)
3.40 (dq, JHH = 13.0 Hz, JHH = 7.2 Hz, 2H, NCH2CH3)
2
3
3
6.5–6.7 (m, 3H, m- and p-C6H5)
6.93 (m, 2H, o-C6H5)
1.36 (t, JHH = 7.0 Hz, 6H, NCH2CH3)
32.6 (s)
32.7 (s)
22.6 (s)
2
3
3.19 (dq, JHH = 13.8 Hz, JHH = 7.0 Hz, 2H, NCH2CH3)
3.45 (dq, JHH = 13.8 Hz, JHH = 7.0 Hz, 2H, NCH2CH3)
2
3
3
3
1866 (s)
1935 (s)
2014 (s)
0.95 (d, JPH = 4.8 Hz, 3H, CH3)
0.80 (t, JHH = 7.2 Hz, 6H, NCH2CH3)
2
3
2.72 (dq, JHH = 14.4 Hz, JHH = 7.2 Hz, 2H, NCH2CH3)
3.10 (dq, JHH = 14.4 Hz, JHH = 7.2 Hz, 2H, NCH2CH3)
2
3
3
1876 (s)
1901 (s)
1961 (s)
2024 (s)
6.6–6.7 (m, 3H, m- and p-C6H5)
6.96 (brs, 2H, o-C6H5)
0.86 (t, JHH = 6.6 Hz, 6H, NCH2CH3)
2.84 (br, 2H, NCH2CH3)
3.12 (br, 2H, NCH2CH3)
3
3bb
5ae
1789 (s)
1886 (s)
6.5–6.6 (m, 3H, m- and p-C6H5)
1.19 (t, JHH = 6.9 Hz, 6H, NCH2CH3)
23.9 (s)
14.2 (s)
3
6.97 (d, JHH = 7.8 Hz, 2H, o-C6H5) 3.2 (br, 4H, NCH2CH3)
3
1686 (s)
1875 (s)
1912 (s)
1945 (s)
2020 (s)
1.99 (s, 3H, COCH3)
1.78 (t, JHH = 6.9 Hz, 6H, NCH2CH3)
2.99 (br, 4H, NCH2CH3)
3
5be
1645 (m)
1890 (s)
1932 (s)
1952 (s)
2027 (m)
7.0–7.3 (m, 5H, COC6H5)
1.25 (t, 6H, JHH = 7.2 Hz, NCH2CH3)
14.6 (s)
3.1 (br, 4H, NCH2CH3)
a
b
c
IR spectra were measured by KBr pellet method.
NMR spectra were measured in acetone-d6.
In CDCl3.
In C6D6.
In CD2Cl2.
d
e

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N. Komine et al. / Journal of Organometallic Chemistry 692 (2007) 4486–4494
C11
C10
C5
N1
O1
C20
C9
C4
C12
O2
C6
C21
C22
Pd1
Co1
C8
C7
C13
P1 C3
C14
C1
C2
O3
C15
C23
O4
C19
C16
C17
C18
Fig. 2. The structure drawing of (Et2NC2H4PPh2-j2N,P)MePd–Co(CO)4
(2a). All hydrogen atoms are omitted for clarity. Ellipsoids represent 50%
probability.
Fig. 1. ORTEP drawing of PdMeI(Et2NC2H4PPh2-j2N,P) (1a). All
hydrogen atoms are omitted for clarity. Ellipsoids represent 50%
˚
IR spectrum of phenylpalladium–molybdenum complex
probability. Selected bond distances (A): Pd(1)–I(1) 2.679(3), Pd(1)–P(1)
(3b) shows strong m(CO) bands at ca. 1780–1890 cmꢀ1
,
2.194(3), Pd(1)–N(1) 2.228(3), Pd(1)–C(1) 2.011(3). Selected bond angles
(ꢁ): I(1)–Pd(1)–N(1) 95.8(1), I(1)–Pd(1)–C(1) 90.5(2), P(1)–Pd(1)–N(1)
84.7(1), P(1)–Pd(1)–C(1), 89.0(2).
which are similar to those for the known anionic Mo(0)
complexes [MoCp(CO)3]ꢀ rather than neutral M(II) com-
plexes such as MoMeCp(CO)3 [4]. The cobalt derivatives,
2a and 2b, also show similar m(CO) bands (1866–
2024 cmꢀ1) as anionic Co(–I) complex, Na+[Co(CO)4]ꢀ
[5]. These data suggest that the actual oxidation states of
the palladium and connecting metals such as molybdenum
and cobalt are close to be Pd(II) and Mo(0) or Co(–I),
which are consistent with the observed geometry of each
metal, although the formal oxidation states are Pd(I) and
Mo(I) or Co(0).
Et
N
2
I
Pd
Pd(dba) + Et NC H PPh + RI
2
2
2
4
2
P
Ph
R
2
R = Me (1a), Ph (1b)
ð1Þ
Metathetical reactions of PdRI(Et2NC2H4PPh2-j2N,P)
(R = Me (1a), Ph (1b)) with excess amounts of
Na+[Co(CO)4]ꢀ in THF at ꢀ40 ꢁC gave novel heterodinu-
clear organopalladium–cobalt complexes having an unsym-
metrical PN ligand, (Et2NC2H4PPh2-j2N,P)RPd–Co(CO)4
(R = Me (2a), Ph (2b)) in 45% and 46% yields, respectively
(Eq. (2)).
The 31P{1H} NMR spectra of 2a,b and 3b show a singlet
around ca. 23–33 ppm, which are lower field from free
ligand, indicating coordination of phosphorus atoms to
the Pd center. The Pd–Me resonance of 2a is observed at
3
d 0.95 as a doublet with a small JPH value (4.8 Hz), sug-
gesting that the Me ligand locates in cis position to the
1
Et
N
Et
N
phosphorus atom. In the H NMR spectra, the methylene
2
2
X
R
ML
R
n
protons of the NCH2CH3 moiety for palladium–cobalt
complexes 2a and 2b were observed diastereotopically, sug-
gesting rigid coordination of the nitrogen atom to the Pd
center. In contrast, the methylene protons of molybdenum
complex 3b appeared as a broad singlet, suggesting involve-
ment of some dynamic processes (vide infra).
+
-
Pd
Pd
+ Na [ML ]
n
THF
P
Ph
P
Ph
2
2
ML = Co(CO)
n
R = Me (2a), Ph (2b)
X = I, NO
4
3
ML = MoCp(CO) R = Ph (3b)
n
3
ð2Þ
When PdMeI(Et2NC2H4PPh2-j2N,P) (1a) was treated
with Na+[MoCp(CO)3]ꢀ, heterometallic tetranuclear com-
plex, [PdMoCp(l-CO)3(Et2NC2H4PPh2-j1P)]2 (4), was
formed in 15% yield, in stead of desired heterodinuclear
methylpalladium–molybdenum complex, (Et2NC2H4PPh2-
j2N,P)MePd–MoCp(CO)3 (3a) [8] (Eq. (3)). X-ray struc-
ture analysis of the crystal of 4 fortunately revealed the
molecular structure, and the ORTEP drawing of 4 is
depicted in Fig. 3. Fate of the methyl group during the
reaction was not clear, though evolution of very small
amount of ethylene was observed.
Similarly, treatment of PdPh(NO3)(Et2NC2H4PPh2-j2N,P),
prepared in situ from 1b and AgNO3, with Na+
[MoCp(CO)3]ꢀ afforded phenylpalladium–molybdenum
derivative (3b) in 76% yield. These novel hetrodinuclear
organopalladium complexes having an unsymmetrical PN li-
gand, 2a,b and 3b, were characterized by NMR and IR spec-
troscopies and elemental analysis. Selected IR and NMR
data of newly prepared compounds, 2a,b and 3b, are summa-
rized in Table 1. Molecular structure of 2a obtained by pre-
liminary X-ray structure analysis is depicted in Fig. 2.

N. Komine et al. / Journal of Organometallic Chemistry 692 (2007) 4486–4494
4489
Mo1
P1*
Pd1
Pd1*
P1
Mo1*
Fig. 3. ORTEP drawing of [PdMoCp(CO)3(Et2NC2H4PPh2-j1P)]2 (4).
All hydrogen atoms are omitted for clarity. Ellipsoids represent 50%
probability.
Fig. 4. Variable-temperature 1H NMR spectra of the diastereotopic
methylene protons in NEt2 moiety of 3b in acetone-d6. Observed spectra:
left, simulated spectra: right.
Cp
Mo
OC
Pd
CO
Pd
Et2 N
Et
N 2 NO3
CO
CO
Mo
+
-
Pd
Ph2P
PPh2
+ Na [MoCp(CO)3]
THF
P
Me
Ph2
NEt2
OC
CO
Cp
platinum complex having a 2-(diphenylphosphino)triethyl-
amine [3a]. From the line shape analysis of these VT NMR
spectra of 3b by gNMR, dissociation rate constants of the
amino group at various temperatures were estimated both in
acetone-d6 and toluene-d8, giving kinetic parameters as fol-
lows: DGz273 ¼ 56:0 ꢁ 0:6 kJ molꢀ1, DHꢀ = 51.3 0.1 kJ
molꢀ1, DSꢀ = ꢀ17.3 1.6 J molꢀ1 Kꢀ1 in acetone-d6 and
DSꢀ = ꢀ11.8 1.7 J molꢀ1 Kꢀ1 in toluene-d8. It is
notable that the DSꢀ values in both acetone and toluene sol-
vents are slightly negative, even though the process is con-
sidered to be an intramolecular dissociative one. The
process possibly involves coordination of intramolecular
bridging of the carbonyl ligand to stabilize the resulting
coordinatively unsaturated species. The methylene protons
of the ethyl group in 2a and 2b appear as well-separated
two signals at ambient temperature, indicating no such
dynamic behavior.
4
ð3Þ
2.2. Dynamic behavior of the PN chelate ligand in
heterodinuclear organopalladium complexes
Variable-temperature 1H NMR of phenylpalladium–
molybdenum complex 3b shows a dynamic behavior of
the resonances due to diastereotopic methylene protons
of the coordinating diethylamino moiety (Fig. 4). The
methylene protons of the ethyl group in 3b appear as a
broad singlet at room temperature. On lowering the tem-
perature as shown in Fig. 4, the signal initially broadens
and then gradually splits into two peaks. At 253 K, two
doublets of quartets with equal intensity appear due to cou-
plings between the diastereotopic geminal protons which
further couple to the methyl protons. On the other hand,
the Cp resonance and phosphorous spectrum shows no
notable change in this temperature range. This is conve-
niently interpreted by the facile and reversible Pd–N bond
rupture, which loses magnetic inequivalency of the methy-
lene protons (Eq. (4)).
DGz273 ¼ 56:9 ꢁ 0:6 kJ molꢀ1, DHꢀ = 53.6 0.1 kJ molꢀ1
,
2.3. CO insertion into carbon–palladium bond of
heterodinuclear organopalladium–cobalt complexes
Reaction of the heterodinucler organopalladium–cobalt
complexes having an unsymmetrical PN ligand (2a,b)
toward CO insertion was investigated (Eq. (5)). Treatment
of the methylpalladium complex 2a with atmospheric CO
at room temperature led to the formation of an acetyl com-
plex, (Et2NC2H4PPh2-j2N,P)(MeCO)Pd–Co(CO)4 (5a).
Under the similar conditions, phenylpalladium complex
2b gave a CO insertion product (Et2NC2H4PPh2-j2N,P)-
(PhCO)Pd–Co(CO)4 (5b) in 75% yield.
Et2
N
OC
MoCp(CO)3
Ph
MoCp(CO)3
Ph
MoCp(CO)2
Ph
Pd
Pd
Pd
P
P
P
Et2N
Et2N
Ph2
Ph2
Ph2
3a
ð4Þ
Such hemilabile behavior had been reported for some
mononuclear platinum or palladium complexes with PN [9]
or bidentate nitrogen ligand [10], and heterodinuclear phenyl-

4490
N. Komine et al. / Journal of Organometallic Chemistry 692 (2007) 4486–4494
Et
N
Et
N
complexes having an unsymmetrical PN ligand, Pd(CO-
Me)I(Et2NC2H4PPh2-j2N,P) (7a), was characterized by
NMR and IR spectroscopies as well as single crystal X-
ray structure analysis, and the ORTEP drawing of 7a is
depicted in Fig. 6.
2
2
Co(CO)
R
Co(CO)
COR
4
4
Pd
Pd
+ CO (0.1 MPa)
THF, rt
P
Ph
P
Ph
2
2
R = Me (5a)
R = Ph (5b)
R = Me (2a)
R = Ph (2b)
By analogy of our previously proposed mechanism for
enhanced CO insertion of methylpalladium–cobalt com-
plex with dppe [2l], a possible mechanism for this CO inser-
tion is proposed (Scheme 1). At first, coordinated nitrogen
atom of PN ligand reversibly dissociates and is displaced
by CO to give (Et2NC2H4PPh2-j1P)(CO)MePd–Co(CO)4.
Similar complex is known in the reaction of platinum
derivative with carbon monoxide [3a]. Then, as previously
proposed in CO insertion into methylpalladium–cobalt
complex with dppe [2g,2l], methyl migration from Pd to
Co initially takes place, followed by fast CO insertion into
the Co–Me bond, and then migration of the resulting acetyl
group at Co to Pd. Coordination of CO ligand to Pd in
(Et2NC2H4PPh2-j1P)(CO)MePd–Co(CO)4 would acceler-
ate methyl migration from Pd to Co. Probably, the higher
reactivity of phenyl complex (2b) for CO insertion is due to
weaker coordination of nitrogen atom to Pd by trans effect
of phenyl group, which is indicated by peak broadening of
ð5Þ
Novel acylpalladium–cobalt complexes, 5a,b, were charac-
terized by NMR and IR spectroscopies and elemental anal-
ysis. IR spectra of these acyl complexes display strong
m(C@O) band due to the PdCOR group at 1686 (5a) or
1645 (5b) cmꢀ1 and a few strong m(C„O) bands at 1875–
2000 cmꢀ1 whose frequencies are close to the broad peaks
of anionic metal carbonyls Na+[Co(CO)4]ꢀ.
CO insertion reactions for methyl or phenylpalladium
complexes were monitored by NMR, employing the sam-
ples of the complexes with concentrations of ca. 0.02 M
in CD2Cl2 at 24 1 ꢁC and 0.1 MPa CO (ca. 9-fold).
Fig. 5 represents time–yield curves of CO insertion to give
corresponding acyl complexes. The methylpalladium–
cobalt complex having an unsymmetrical PN ligand (2a)
gave a significantly higher activity than the corresponding
mononuclear palladium complex 1a and the methylpalla-
dium–cobalt complex with dppe ligands, (dppe-j2P,P0)-
MePd–Co(CO)4 (6a) [2g,2l]. The CO insertion reaction of
phenyl derivative 2b was significantly faster than methyl
complex 2a. The significant acceleration for the CO inser-
tion reaction may be attributable to facile formation of a
vacant coordination site by the preferential dissociation
of nitrogen ligand in 2a or 2b though such site locates trans
to Me or Ph. Hence, it is clearly shown that the CO inser-
tion is enhanced by both the Co(CO)4 group and unsym-
metrical PN ligand. Mononuclear acetylpalladium
1
methylene signal of NCH2CH3 in H NMR.
2.4. Reactions of acetylpalladium–cobalt complexes with
nucleophiles
Reactions of the acetyl complex 5a with nucleophiles
such as diethylamine, methanol and benzenethiol were
100
80
60
40
20
0
I1
Fig. 6. ORTEP drawings of Pd(COMe)I(Et2NC2H4PPh2-j2N,P) (7a). All
hydrogen atoms are omitted for clarity. Ellipsoids represent 50%
0
1
2
3
4
)
time (h
˚
probability. Selected bond distances (A): Pd(1)–I(1) 2.6703(6), Pd(1)–
Fig. 5. Time–yieldcurvesofacylpalladiumcomplexformedbyCOinsertion
into carbon–palladium bond of methyl- or phenylpalladium complexes at
24 1 ꢁC: (Et2NC2H4PPh2j2N,P)(MeCO)Pd–Co(CO)4 (5a, d), (Et2NC2-
H4PPh2-j2N,P)(PhCO)Pd–Co(CO)4 (5b, s), Pd(COMe)I(Et2NC2H4PPh2-
j2N,P) (7a, ·), and (dppe-j2P,P0)(MeCO)Pd–Co(CO)4 (8a, h).
P(1) 2.253(1), Pd(1)–N(1) 2.271(4), Pd(1)–C(1) 1.982(4), C(1)–C(2)
1.490(7), C(1)–O(1) 1.214(6). Selected bond angles (ꢁ): I(1)–Pd(1)–N(1)
96.03(9), I(1)–Pd(1)–C(1) 88.8(1), P(1)–Pd(1)–N(1) 84.67(9), P(1)–Pd(1)–
C(1) 92.1(1), Pd(1)–C(1)-O(1) 119.2(4), Pd(1)–C(1)–C(2) 118.8(3), O(1)–
C(1)–C(2) 121.9(4).

N. Komine et al. / Journal of Organometallic Chemistry 692 (2007) 4486–4494
4491
O
Et
N
2
OC
P
C
OC
P
Co(CO)
Me
4
Co(CO)
Me
4
Pd
CO
Pd
Co(CO)
Me
2
Pd
C
O
Et N
2
Et N
2
P
Ph
Ph
Ph
2
2
2
Et
O
C
2
OC
N
Co(CO)
COMe
4
Pd
Pd
P
Ph
Co(CO)
COMe
P
Ph
C
O
Et N
2
2
2
Scheme 1.
Table 2
Reactions of acetylpalladium complexes with nucleophilesa
having an unsymmetrical PN ligand (Et2NC2H4PPh2-j
2N,P)RPd–MLn (MLn = Co(CO)4; R = Me (2a), Ph (2b),
MLn = MoCp(CO)3; R = Ph (3b)) was described. Heterod-
inucler organopalladium–cobalt complexes (2a,b) are
shown to react with CO, giving corresponding acyl com-
plexes (Et2NC2H4PPh2-j2N,P)(RCO)Pd–Co(CO)4 (R =
Me (5a), Ph (5b)). Similar acceleration by PN ligand was
previously observed for CO insertion of the methylplati-
num derivative [3a]. The CO insertion reaction of phenyl
derivative 2b was significantly faster than methyl complex
2a. Probably, this higher reactivity of phenyl complex
(2b) for CO insertion is depending on weaker coordination
of nitrogen atom to Pd. The reactions of 5a with Et2NH
are significantly faster than those of corresponding mono-
nuclear analogues and the similar heterodinuclear com-
plexes with a symmetrical bidentate ligand such as dppe
or tmeda. The unsymmetrical PN ligand in heterodinucler
organopalladium–cobalt complex is considered to play an
important role in accelerating CO insertion of palladium–
carbon bond as well as nucelophilic attack to acyl carbon
center.
Entry
Complex
Nucleophile
Yield (%)
1
5a
5a
5a
7a
8a
9a
Et2NH
MeOH
PhSH
Et2NH
Et2NH
Et2NH
87
79
93
0
15
Trace
2b
3c
4
5
6
a
Reaction conditions: acetylpalladium complex (0.006 mmol), nucleo-
philes (0.03 mmol), C6D6 (0.5 ml), 50 ꢁC, 24 h.
b
Acetone-d6 (0.5 ml), rt, 4 days.
Acetone-d6 (0.5 ml), rt, 30 min.
c
investigated, and the results are summarized in Table 2.
Treatment of 5a with diethylamine at 50 ꢁC for 24 h in
C6D6 gave N,N-diethyl acetamide in 87% yield (Table 2,
entry 1). Similarly, the reaction of 5a with methanol and
benzenethiol at room temperature in acetone-d6 afforded
methyl acetate and phenyl thioacetate in 79% and 93%
yields, respectively (entries 2 and 3). It is interesting to note
that under the same reaction conditions, (dppe-
j2P,P0)(MeCO)Pd–Co(CO)4 (8a) [2g,2l] showed much less
reactivity toward Et2NH (15%), and (tmeda-j2N,N0)-
(MeCO)Pd–Co(CO)4 (9a) [2k] and Pd(COMe)I(Et2N-
C2H4PPh2-j2N,P) (7a) showed almost no reactivity (entries
4–6). The present higher reactivity of 5a may also attribute
to the facile dissociation of PN ligand, though the detail
mechanisms are not clear at present.
4. Experimental
4.1. General
All manipulations were carried out under dry nitrogen
or argon atmosphere using standard Schlenk and vacuum
line techniques [11]. Solvents were refluxed over and dis-
tilled from appropriate drying agents under N2: benzene,
toluene, hexane, and THF from sodium benzophenone
ketyl; acetone from drierite; CH2Cl2 from P2O5. Deuter-
ated solvents were degassed by three freeze–pump–thaw
cycles and then vacuum transferred from appropriate dry-
ing agents (C6D6 and toluene-d8 from sodium wire, ace-
tone-d6 from drierite, CD2Cl2 and CDCl3 from P2O5).
Pd2(dba)3 Æ CHCl3 [6], Et2NC2H4PPh2 [7], Na+[MoCp
(CO)3]ꢀ [4] and Na+[Co(CO)4]ꢀ [5] were prepared accord-
ing to the literature methods with minor modifications.
AgNO3 and CO (99.9%) were used as received. NMR spec-
tra were recorded on a JEOL LA-300 spectrometer
L
L
Co(CO)
COMe
4
Pd
MeCONu
ð6Þ
+ NuH
L
= Et NC H PPh (5a)
2 2 4 2
2
dppe (8a)
tmeda (9a)
3. Conclusions
1
(300.4 MHz for H, 121.6 MHz for 31P). Chemical shifts
In the present study, synthesis of novel heterodinuclear
organopalladium–cobalt (or –molybdenum) complexes
were reported in ppm downfield from TMS for 1H and from

4492
N. Komine et al. / Journal of Organometallic Chemistry 692 (2007) 4486–4494
85% H3PO4 in D2O for 31P. IR spectra were recorded on a
JASCO FT/IR-410 spectrometer using KBr disks. Elemen-
tal analyses were carried out with a Perkin–Elmer 2400 ser-
ies II CHN analyzer. Molar electric conductivity was
measured on a TOA Conduct Meter CM 7B. Line shape
analysis was performed with the gNMR program [12] by fit-
ting of the exchange rate and resonance frequency.
perature. Yield 45% (52.6 mg, 0.0910 mmol). Anal. Calc.
for C23H27CoNO4PPd: C, 47.81; H, 4.71; N, 2.42. Found:
C, 48.16; H, 4.81; N, 3.05%. IR (KBr, cmꢀ1): 2014(s),
1935(s), 1866(s). 1H NMR (C6D6, rt):
d 0.80 (t,
3
3JHH = 7.2 Hz, 6H, NCH2CH3), 0.95 (d, JPH = 4.8 Hz,
3H, PdCH3), 1.7–1.9 (m, 4H, PCH2CH2N), 2.72 (dq,
3
2JHH = 14.4 Hz, JHH = 7.2 Hz, 2H, NCH2CH3), 3.10
2
3
(dq, JHH = 14.4 Hz, JHH = 7.2 Hz, 2H, NCH2CH3), 7.0
(m, 6H, m- and p-Ph), 7.5 (m, 4H, o-Ph). 31P{1H} NMR
(C6D6, rt): d 32.7 (s).
4.2. Synthesis of PdRI(Et2NC2H4PPh2-j2N,P)
4.2.1. PdMeI(Et2NC2H4PPh2-j2N,P) (1a)
To a benzene solution of Pd2(dba)3 Æ CHCl3 (791.3 mg,
0.7657 mmol) was added Et2NC2H4PPh2 (0.38 ml,
1.8 mmol) and methyl iodide (0.12 ml, 1.9 mmol) at room
temperature. The reaction mixture was stirred at room tem-
perature for overnight. After filtration through an alumina
pad, the filtrate was evaporated to dryness in vacuo giving
orange solid, which was washed with hexane. Recrystalliza-
tion from CH2Cl2/hexane gave orange crystals. Yield 46%
(374.9 mg, 0.7024 mmol). Anal. Calc. for C19H27INPPd: C,
42.76; H, 5.10; N, 2.62. Found: C, 42.43; H, 4.85; N,
4.3.1. (Et2NC2H4PPh2-j2N,P)PhPd–Co(CO)4 (2b)
This compound was obtained as orange crystals from
THF/hexane. Yield 46% (41.5 mg, 0.0649 mmol). Anal.
Calc. for C28H29CoNO4PPd Æ C4H8O: C, 53.98; H, 5.24;
N, 1.97. Found: C, 54.02; H, 5.14; N, 2.05%. IR (KBr,
1
cmꢀ1): 2024(s), 1961(s), 1901(s), 1876(s). H NMR (C6D6,
3
rt): d 0.86 (t, JHH = 6.6 Hz, 6H, NCH2CH3), 1.3–1.5 (m,
4H, PCH2CH2N), 2.84 (br, 2H, NCH2CH3), 3.12 (br,
2H, NCH2CH3), 6.6–6.7 (m, 3H, m- and p-Ph (Pd-Ph)),
6.96 (brs, 2H, o-Ph (Pd-Ph)), 7.2–7.5 (m, 10H, Ph (P-
Ph)). 31P{1H} NMR (C6D6, rt): d 22.6 (s).
1
3
2.50%. H NMR (acetone-d6, rt): d 0.65 (d, JPH = 3.9 Hz,
3
3H, PdCH3), 1.20 (t, JHH = 7.2 Hz, 6H, NCH2CH3), 2.5–
2
2.9 (m, 4H, PCH2CH2N), 3.05 (dq, JHH = 13.0 Hz,
4.3.2. (Et2NC2H4PPh2-j2N,P)PhPd–MoCp(CO)3 (3b)
This compound was obtained as orange crystals from
THF/hexane. Yield 76% (108.5 mg, 0.1520 mmol). Anal.
Calc. for C32H34MoNO3PPd: C, 53.83; H, 4.80; N, 1.96.
Found: C, 53.90; H, 5.12; N, 1.96%. IR (KBr, cmꢀ1):
1886(s), 1789(s). 1H NMR (acetone-d6, rt): d 1.19 (t,
3JHH = 6.9 Hz, 6H, NCH2CH3), 2.6–2.8 (m, 4H,
PCH2CH2N), 3.2 (br, 4H, NCH2CH3), 4.63 (s, 5H, Cp),
6.5–6.6 (m, 3H, m- and p-Ph (Pd-Ph)), 6.97 (d,
3JHH = 7.8 Hz, 2H, o-Ph (Pd-Ph)), 7.4-7.5 (m, 10H, Ph
(P-Ph)). 31P{1H} NMR (acetone-d6, rt): d 23.9 (s).
3JHH = 7.2 Hz, 2H, NCH2CH3), 3.40 (dq, 2JHH = 13.0 Hz,
3JHH = 7.2 Hz, 2H, NCH2CH3), 7.52–7.64 (m, 6H, m- and
p-Ph), 7.72–7.80 (m, 4H, o-Ph). 31P{1H} NMR (acetone-d6,
rt): d 42.4 (s).
4.2.2. PdPhI(Et2NC2H4PPh2-j2N,P) (1b)
PhI was used instead of MeI. This compound was
obtained as orange crystals from CH2Cl2/hexane. Yield
14% (86.7 mg, 0.145 mmol). Anal. Calc. for C24H29INPPd:
C, 48.38; H, 4.91; N, 2.35. Found: C, 48.24; H, 5.30; N,
3
2.34%. 1H NMR (CDCl3, rt): d 1.36 (t, JHH = 7.0 Hz,
6H, NCH2CH3), 2.4–2.7 (m, 4H, PCH2CH2N), 3.19 (dq,
4.3.3. [PdMoCp(CO)3(Et2NCH2CH2PPh2-j1P)]2 (4)
This compound was obtained by the same procedure as
above as white crystals from benzene/hexane, but charac-
terized by spectroscopically as well as by X-ray structure
analysis. Yield 15% (6.3 mg, 0.0099 mmol). IR (KBr,
cmꢀ1): 1833(s), 1767(s). 1H NMR (C6D6, rt): d 1.02 (t,
3
2JHH = 13.8 Hz, JHH = 7.0 Hz, 2H, NCH2CH3), 3.45
2
3
(dq, JHH = 13.8 Hz, JHH = 7.0 Hz, 2H, NCH2CH3),
6.5–6.7 (m, 3H, m- and p-Ph (Pd-Ph)), 6.93 (m, 2H, o-Ph
(Pd-Ph)), 7.3–7.8 (10H, m, Ph(P-Ph)). 31P{1H} NMR
(CDCl3, rt): d 32.6 (s).
3
3JHH = 7.1 Hz, 6 H, NCH2CH3), 2.55 (q, JHH = 7.1 Hz,
4.3. Synthesis of heterodinucler organopalladium complexes
having an unsymmetrical PN ligand
4H, NCH2CH3), 2.78 (m, 2H, PCH2CH2N), 3.12 (m, 2H,
PCH2CH2N), 4.64 (s, 5H, Cp), 6.9-7.2 (m, 6H, m- and p-
Ph (P-Ph)), 7.6 (m, 4H, o-Ph (P-Ph)). 31P{1H} NMR
(C6D6, rt): d 12.9 (s).
A typical procedure for (Et2NC2H4PPh2-j2N,P)MePd–
Co(CO)4 (2a) is given. To
a
THF solution of
PdMeI(Et2NC2H4PPh2-j2N,P) (108.3 mg, 0.2040 mmol),
a THF solution of Na+[Co(CO)4]ꢀ (35.2 mg, 0.182 mmol)
was added at ꢀ80 ꢁC and the mixture was stirred at
ꢀ40 ꢁC for 3 h. All volatile matters were removed by evap-
oration and the resulting brown-yellow solid was extracted
with toluene at ꢀ30 ꢁC. After the filtered solution was con-
centrated under reduced pressure at ꢀ20 ꢁC, an excess hex-
ane was added. The solution was cooled to ꢀ30 ꢁC to give
pale yellow needles of 2a. The product was filtered, and
washed with hexane, and dried under vacuum at room tem-
4.4. Synthesis of acylpalladium complexes by CO insertion
A typical preparative procedure of (Et2NC2H4PPh2-
j2N,P)(MeCO)Pd–Co(CO)4 (5a) is given. 2a (51.7 mg,
0.0894 mmol) was dissolved in THF under N2 in a Schlenk
tube and the solution was degassed. CO (0.1 MPa) was
introduced into the Schlenk tube and the orange solution
turned to red after stirring for 16 h. After filtration of the
reaction mixture, the filtered solution was evaporated to
dryness. The resulting solids were extracted with THF

N. Komine et al. / Journal of Organometallic Chemistry 692 (2007) 4486–4494
4493
and addition of hexane to the concentrated solution of
4.7. X-ray structure analyses of PdMeI(Et2NC2H4PPh2-
extracts gave yellow needles. The crystals were washed with
cold hexane and dried under vacuum. Yield 19% (10.2 mg,
0.0168 mmol). Anal. Calc. for C24H27CoNO5PPd: C,
47.58; H, 4.49; N, 2.31. Found: C, 47.44; H, 4.62; N,
2.32%. IR (KBr, cmꢀ1): 2020(s), 1945(s), 1912(s), 1875(s),
j2N,P) (1a), (Et2NC2H4PPh2-j2N,P)MePd–Co(CO)4
(2a), [PdMoCp(CO)3(Et2NC2H4PPh2-j1P)]2 (4) and
Pd(COMe)I(Et2NC2H4PPh2-j2N,P) (7a)
Diffraction experiments were performed on a Rigaku
four-circle diffractometer RASA-7R diffractometer with
graphite-monochromatized Mo Ka radiation (0.71069
1
3
1686(s). H NMR (CD2Cl2, rt): d 1.78 (t, JHH = 6.9 Hz,
6H, NCH2CH3), 1.99 (s, 3 H, PdCOCH3), 2.4-2.6 (m,
4H, PCH2CH2N), 2.99 (br, 4H, NCH2CH3), 7.6 (m, 6H,
m- and p-Ph), 7.8 (m, 4H, o-Ph). 31P{1H} NMR (CD2Cl2,
rt): d 14.2 (s).
˚
A). A single crystal was selected by use of a polarized
microscope and mounted in a capillary tube (GLASS,
0.7 mm/), which was sealed by small flame torch. The
unit cells were determined by the automatic indexing of
the 20 centered reflections. The structures were solved
and refined by a full matrix least-square procedure using
the texsan crystal solution package (Rigaku) operating
on a SGI O2 workstation [13]. An absorption correction
for 1a, 4, and 7a was applied with the program w-scan.
The structures of 1a and 4 were solved by direct methods,
and the structures of 7a were solved by Patterson methods
(SAPI). For these complexes, all non-hydrogen atoms
were found on difference Fourier maps, and refined aniso-
tropically expect C5 and C6 of 4, and all hydrogen atoms
were located in the calculated positions, which were not
refined. Due to low quality of the crystal of 2a, non-
hydrogen atoms expect Pd1 and Co1 atoms were refined
with isotropic displacement parameters, and Ph rings
and CO ligands were treated as fixed groups, and all
hydrogen atoms were located in the calculated positions,
which were not refined. Therefore, no structural feature
4.4.1. (Et2NC2H4PPh2-j2N,P)(PhCO)Pd–Co(CO)4 (5b)
This compound was obtained as yellow powder from
THF/hexane. Yield 75% (55.2 mg, 0.0827 mmol). Anal.
Calc. for C29H29CoNO5PPd: C, 52.15; H, 4.38; N, 2.10.
Found: C, 52.64; H, 4.62; N, 2.15%. IR (KBr, cmꢀ1):
1
2027 (m), 1952 (s), 1932 (s), 1890 (s), 1645 (m). H NMR
3
(C6D6, rt): d 1.25 (t, 6H, JHH = 7.2 Hz, NCH2CH3), 2.4–
2.6 (m, 4H, PCH2CH2N), 3.1 (br, 4H, NCH2CH3), 7.0–
7.3 (m, 5H, Ph (PdCO-Ph)), 7.5–8.0 (m, 10H, Ph (P-Ph)).
31P{1H} NMR (C6D6, rt): d 14.6 (s).
4.4.2. Pd(COMe)I(Et2NC2H4PPh2-j2N,P) (7a)
This compound was obtained as yellow powder from
acetone/hexane. Yield 93% (127.8 mg, 0.2275 mmol). Anal.
Calc. for C29H29CoNO5PPd: C, 42.76; H, 4.84; N,
2.49. Found: C, 42.70; H, 4.58; N, 2.59%. IR (KBr,
1
3
cmꢀ1): 1650 (m). H NMR (C6D6, rt): d 0.97 (t, JHH
=
˚
7.2 Hz, 6H, NCH2CH3), 1.6–1.8 (m, 4H, PCH2CH2N),
2.67 (br, 2H, NCH2CH3), 3.08 (m, 2H, NCH2CH3), 7.0–
7.5 (m, 10H, Ph (P-Ph)). 31P{1H} NMR (C6D6, rt): d
20.3 (s).
was discussed in the text. Selected bond distances (A)
for 2a: Pd(1)–Co(1) 2.667(3), Pd(1)–P(1) 2.233(6), Pd(1)–
N(1) 2.27(2), Pd(1)–C(1) 1.98(2), Pd(1)–C(20) 2.42(12),
Pd(1)–C(23) 2.70(10). Selected bond angles (ꢁ) for 2a:
Co(1)–Pd(1)–N(1) 96.8(5), Co(1)–Pd(1)–C(1) 88.3(6),
P(1)–Pd(1)–N(1) 85.2(5), P(1)–Pd(1)–C(1) 89.3(6). Crystal
data for 1a: C19H27INPPd, FW = 533.71, orthorhombic,
4.5. NMR tube reactions for CO insertion of
organopalladium complex
˚
˚
˚
Pbca, a = 13.2 (1) A, b = 25.17(9) A, c = 12.21(8) A,
3
V = 4057(43) A , Z = 8, Dcalc = 1.744 g cmꢀ3
,
l(Mo
˚
A typical procedure for 2a is given. C6D6 (0.5 mL) was
vacuum-transferred to an NMR tube (5 mm/ · 180 mm)
containing 2a (5.1 mg, 0.0088 mmol), and Ph3CH was
added as an internal standard to the solution
([2a] = 0.018 M). The solution was degassed by freeze–
pump–thaw cycles and CO (0.1 MPa) was introduced.
The sample tube was placed in NMR probe at 24 1 ꢁC,
and 1H NMR spectra were periodically measured to follow
the CO insertion reaction at 24 1 ꢁC.
Ka) = 25.12 cmꢀ1, 2hmax = 56.0 ꢁ, 5293 reflections mea-
sured (5263 unique), 4271 observations with I > 3.00r(I),
R (Rw) = 0.028 (0.063), GOF = 1.86. Crystal data for 2a:
C23H27CoNO4PPd, FW = 577.78, monoclinic, P21, a =
˚
˚
˚
8.442(5) A, b = 14.761(6) A, c = 12.244(7) A, b = 102.61
(5)ꢁ, V = 1488(1) A , Z = 2, Dcalc = 1.289 g cmꢀ3, l(Mo
3
˚
Ka) = 12.39 cmꢀ1, 2hmax = 55.0ꢁ, 3778 reflections mea-
sured (3718 unique), 3226 observations with I >
3.00r(I), R (Rw) = 0.125 (0.178), GOF = 1.68. Crystal
data for 4: C26H29MoNO3PPd, FW = 636.83, triclinic,
4.6. Reactions of acetylpalladium–cobalt complexes with
nucleophiles
˚
˚
˚
ꢀ
P1, a = 10.73(5) A, b = 12.81(3) A, c = 10.56(4) A, a =
3
˚
90.2(3)ꢁ, b = 117.9(3)ꢁ, c = 76.6(3)ꢁ, V = 1238(9) A ,
A typical procedure for 5a with Et2NH is given. Com-
plex 5a (3.6 mg, 0.0053 mmol) was placed in an NMR tube
with Ph3CH as an internal standard, and C6D6 (0.5 mL)
was added under N2 atmosphere. Et2NH (2.7 lL,
0.026 mmol) was added to the solution by hypodermic syr-
inge and then heated at 50 ꢁC for 24 h. Products were
Z = 2, Dcalc = 1.707 g cmꢀ3 l(Mo Ka) = 13.24 cmꢀ1
, ,
2hmax = 55.4 ꢁ, 6018 reflections measured (5707 unique),
4466 observations with I > 3.00r(I), (Rw) = 0.063
R
(0.102), GOF = 1.14. Crystal data for 7a: C20H27OINPPd,
˚
FW = 561.72, orthorhombic, Pna21, a = 17.120(3) A,
3
˚
˚
˚
b = 7.890(3) A, c = 15.736(3) A, V = 2125(1) A , Z = 4,
1
quantitatively analyzed by H NMR.
Dcalc = 1.755 gcmꢀ3, l(Mo Ka) = 24.10 cmꢀ1, 2hmax
=

4494
N. Komine et al. / Journal of Organometallic Chemistry 692 (2007) 4486–4494
(i) S. Komiya, T. Yasuda, A. Fukuoka, M. Hirano, J. Mol. Catal. A
159 (2000) 63;
(j) S. Komiya, S. Muroi, M. Furuya, M. Hirano, J. Am. Chem. Soc.
122 (2000) 170;
55.0 ꢁ, 2798 reflections measured (2529 unique), 2385
observations with I > 3.00r(I), R (Rw) = 0.020 (0.024),
GOF = 1.09.
(k) N. Komine, H. Hoh, M. Hirano, S. Komiya, Organometallics 19
(2000) 5251;
Acknowledgments
(l) A. Fukuoka, S. Fukagawa, M. Hirano, N. Koga, S. Komiya,
Organometallics 20 (2001) 2065;
(m) M. Furuya, S. Tsutsuminai, H. Nagasawa, N. Komine, M.
Hirano, S. Komiya, Chem. Commun. (2003) 2046;
(n) N. Komine, S. Tanaka, S. Tsutsuminai, Y. Akahane, M. Hirano,
S. Komiya, Chem. Lett. 33 (2004) 858;
(o) A. Kuramoto, K. Nakanishi, T. Kawabata, N. Komine, M.
Hirano, S. Komiya, Organometallics 25 (2006) 311;
(p) N. Komine, S. Tsutsuminai, H. Hoh, T. Yasuda, M. Hirano, S.
Komiya, Inorg. Chem. Acta 359 (2006) 3699;
The work was financially supported by Grant-in-Aid for
Scientific Research from the Ministry of Education, Sci-
ence, Culture, Sports, Science and Technology, Japan
and the 21th Century COE program of ‘‘Future Nano-
materials’’ in Tokyo University of Agriculture and
Technology.
Appendix A. Supplementary material
(q) S. Tanaka, H. Hoh, Y. Akahane, S. Tsutsuminai, N. Komine,
M. Hirano, S. Komiya, J. Organomet. Chem. 692 (2007) 26.
[3] (a) S. Tsutsuminai, N. Komine, M. Hirano, S. Komiya, Organomet-
allics 22 (2003) 4238;
(b) S. Tsutsuminai, N. Komine, M. Hirano, S. Komiya, Organomet-
allics 23 (2004) 44.
[4] (a) T.S. Piper, G. Wilkinson, J. Inorg. Nucl. Chem. 3 (1956) 104;
(b) J.M. Burlitch, T.W. Theyson, J. Chem. Soc., Dalton Trans. (1974)
828.
[5] J.K. Ruff, W.J. Schlientz, Inorg. Synth. 15 (1957) 192.
[6] T. Ukai, H. Kitagawa, Y. Ishii, J. Organomet. Chem. 65 (1974) 253.
[7] V.D. Bianco, S. Doronzo, Inorg. Synth. 16 (1976) 155.
[8] (a) Synthesis and molecular structure of similar structural complexes,
[PdMoCp(l-CO)3(PR3)]2 (PR3 = PMe3, PEt3, PBu3, PMe2Ph, PPh3)
were previously reported: R. Bender, P. Braunstein, J.M. Jud, Y.
Dusausoy, Inorg. Chem. 22 (1983) 3394;
CCDC 633363, 633364, 633365 and 633366 contain the
supplementary crystallographic data for 1a, 2a, 4 and 7a.
These data can be obtained free of charge via http://
www.ccdc.cam.ac.uk/conts/retrieving.html, or from the
Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: (+44) 1223-336-033; or e-
mail: deposit@ccdc.cam.ac.uk. Supplementary data associ-
ated with this article can be found, in the online version, at
doi:10.1016/j.jorganchem.2007.04.029.
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