Synthesis and characterization of nickel and palladium complexes containing hetero-multidentate PNO ligands

Article abstract of DOI:10.1016/j.ica.2005.03.034

Formation of mono- and dinuclear complexes containing ligands stemmed from the condensation of 2,6-diformyl-4-methylphenol derivatives with 2-(diphenylphosphino)aniline (P～N) was investigated. Condensation of P～N with 2,6-diformyl-4-methylanisole yielded

Full text of DOI:10.1016/j.ica.2005.03.034

Inorganica Chimica Acta 358 (2005) 3003–3008
www.elsevier.com/locate/ica
Synthesis and characterization of nickel and palladium
complexes containing hetero-multidentate PNO ligands
*
Srinivas R. Korupoju, Rung-Yi Lai, Yi-Hong Liu, Shie-Ming Peng, Shiuh-Tzung Liu
Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan, ROC
Received 18 September 2004; accepted 14 March 2005
Available online 26 April 2005
Abstract
Formation of mono- and dinuclear complexes containing ligands stemmed from the condensation of 2,6-diformyl-4-methylphenol
derivatives with 2-(diphenylphosphino)aniline (PꢀN) was investigated. Condensation of PꢀN with 2,6-diformyl-4-methylanisole
yielded the desired bis(imine-phosphine) L3, but provided the cyclized benzoazaphospholium compound with 2,6-diformyl-4-
methylphenol. Complexation of L3 with (COD)PdCl2 gave the dinuclear complex 4. On the other hand, L3 underwent the
intramolecular cyclization in the presence of (DME)NiCl2 via the formation of benzoazaphospholium rings. Template condensation
of 2,6-diformyl-4-methylphenol with PꢀN in the presence of metal ions yielded the mononuclear nickel(II) and palladium(II)
complexes, respectively.
ꢀ 2005 Elsevier B.V. All rights reserved.
Keywords: Iminophosphine; Heterotridentate; Nickel; Palladium; Multidentate
1. Introduction
whereas ligand LB demonstrated the versatility in the
formation of Ni(II) [6a], Pd(II) [4,6], Pt(II) [6], and
Ru(II) [7] complexes as a tridentate. The binuclear
Rh(I) complexes of ligand LC were studied for hydrosi-
lylation of ketones [8]. In our laboratory, the coordina-
tion behavior of ligand LD toward palladium(II) was
investigated [9,10]. Continuing this trend, we pursue to
synthesize new multi-chelating ligands Ln (Scheme 1)
from 2,6-diformyl-4-methylphenol and study the coordi-
nation ability of these related mutlidentates toward
Pd(II) and Ni(II) ions.
There is a considerable interest in the design and syn-
thesis of ligands consisting of both soft and hard donors
to accommodate metal ions for fine-tuning their proper-
ties [1]. Accordingly, unsymmetrical bidentate ligands
with a nitrogen and a phosphorus donor atoms [referred
to as PN ligands] have received much attention recently,
due to the distinct trans effect of these donors [2]. Fur-
thermore, heterotridentate PNO ligands resulted from
the combination of PN with an extra oxygen donor dis-
playing unique features in manipulating the catalytic
activity on polymerization [3,4]. Several other known
PNO ligands involving an o-phenylene PN frame are ap-
peared in Chart 1. Ligand LA was studied for the coor-
dination toward Fe(III), Co(III) and Re(V) ions [5],
2. Results and discussion
2.1. Preparation of ligands
In an attempt to synthesize the ligand L2 by the con-
densation of 2,6-diformyl-4-methylphenol with 2-(diph-
enylphosphino)aniline (PꢀN) (1:2) in the presence of a
*
Corresponding author. Tel.: +886 2 2366 0352; fax: +886 2 2363
6359.
E-mail address: stliu@ntu.edu.tw (S.-T. Liu).
0020-1693/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2005.03.034

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S.R. Korupoju et al. / Inorganica Chimica Acta 358 (2005) 3003–3008
PPh2
PPh2
N
PPh2
PPh2
N
Ph2P
OH
N
OCH3
N
OH
OH
N
Y
OCH3
LA
LB
LC
LD
Chart 1. Various PNO ligands.
O
N
N
R
NH2
R = CH3
+
PPh2
Ph2P
PPh2
L
2 R = H
O
O
OR
L3 R = CH3
Cl-
PPh2
R = H
2+
Ph2
P
Ph2
P
OH
N
HN
OH
2 Cl-
NH
HN
PPh2
L4
L1
Scheme 1. Ligand synthesis.
trace amount of conc. HCl in toluene under nitrogen
atmosphere afforded the one side cyclized benzoaza-
phospholium schiff base ligand L1 instead of the antici-
pated ligand L2 (Scheme 1). The 31P NMR spectrum
showed two absorptions at ꢁ14.8 and 36.8 ppm, which
were corresponding to the tert-phosphine and the cyc-
lized benzoazaphospholium group [11], respectively.
The infrared spectrum showed a strong absorption at
1624 cmꢁ1 manifesting the formation of imine function-
ring. It has been known that condensation of PꢀN with
a carbonyl compound in the presence of acid could pro-
vide the cyclized benzoazaphospholium products [11].
2.2. Nickel(II) complexes
Reaction of L3 with Ni(DME)Cl2 (1:2) in dichloro-
methane resulted in the cyclization of ligand to form
the azaphospholium 1 in 28% isolated yield. (Eq. (1))
Recrystallization from dichloromethane and hexane
gave light blue crystals. The 31P NMR spectrum of the
compound shows only one singlet absorption at 41.2
ppm, which is typical for the phosphonium group. The
X-ray structural characterization of the complex shows
the formation of bis-benzoazaphospholium ring of the
ligand with the [NiCl4]ꢁ2 as counter anion (Fig. 1). It ap-
peared that the phosphorus and nitrogen donors do not
bound to the metal ion. Distances of C(9)–N(2) [1.464(6)
1
ality, which was also evidenced by the H NMR signal
at 8.32 ppm for the imino proton. Interestingly, the
bis-benzoazaphospholium compound L4 was obtained
when the reaction was carried out in a polar solvent such
as dichloromethane (see below).
Under similar conditions, reaction of 2,6-diformyl-4-
methylanisole with PꢀN in a molar ratio of 1:2 afforded
the bis-imine ligand L3 in good yield (70%). Crystalliza-
tion from dichloromethane and hexane gave lemon yel-
low crystals. IR spectrum shows a strong characteristic
absorption for imine group at 1617 cmꢁ1. The 31P
NMR spectrum exhibits one signal at ꢁ16.1 ppm corre-
sponding to the presence of a tert-diphenylphosphino
group. All spectral data including 1H, 13C NMR as well
as FAB mass spectrum and elemental analysis of L3 are
consistent with the structure proposed. From the above
observation, it is assumed that the phenolic proton read-
ily facilitates the cyclization of benzoazaphospholium
˚
˚
A] and C(28)–N(1) [1.476(6) A] are typical for a C–N
single bond, indicating that the molecule does not in-
clude any imine functionality. Examination of the car-
bon to phosphorus distances and the associated bond
angle clearly shows that the phosphorus atom is seated
in a tetrahedral geometry, a typical phosphonium salt.
It appears that the nickel ions act as Lewis acid to cata-
lyze the cyclization of the phospholium ions and under-
go the disproportionation to yield [NiCl4]2ꢁ, which

S.R. Korupoju et al. / Inorganica Chimica Acta 358 (2005) 3003–3008
3005
Ph2
P
Cl-
OH
+
O
O
(DME)NiCl2
O
N
P
HN
H2N
Ni
Cl
Ph2
Ph2P
2
ð2Þ
ORTEP plot of 2 with partial atom labeling is pre-
sented in Fig. 2. Selected bond distances and bond an-
gles are summarized in Table 1. The charge of nickel
ion was neutralized with ligand phenoxide group and
chloride anion, whereas the positive charge was located
at phosphorus center of the phosphazolium group. The
nickel(II) center was seated in a slightly distorted square
planar geometry by the coordination of ligand PNO do-
nors and a chloride. The chloride group bound trans to
the imine nitrogen. Angles of O–Ni–P [175.19(9)ꢁ] and
N–Ni–Cl [174.96(9)ꢁ] are less than 180ꢁ presumably
due to steric arrangement of the PꢀNꢀO donors. Bond
˚
Fig. 1. ORTEP plot of complex 1. Average Ni–Cl 2.257 A, C(2)–C(9)
˚
˚
˚
1.518(7) A; C(9)–N(2) 1.464(6) A; P(1)–C(9) 1.872(5) A; N(2)–C(10)
˚
˚
˚
1.369(7) A; C(15)–P(1) 1.772(5) A; N(1)–C(28) 1.476(6) A; C(28)–P(2)
˚
1.857(5) A; P(2)–C(34) 1.759(6) A; N(1)–C(29) 1.391(7) A.
˚
˚
provides the appropriate anions to form the single crys-
tal of 1. In fact, some of the starting nickel(II) complex
was recovered.
2+
Ph2
P
H
N
(DME)NiCl2
[NiCl4]2-
L3
O
PPh2
HN
˚
distance of the newly formed C(9)–P(2) [1.853(4) A] is
CH3
1
ð1Þ
On the other hand, template condensation method, a
common approach to construct the oxo-bridge bimetal-
lic species, was employed to synthesize the phenoxo
bridged dinuclear nickel complex. Thus, a mixture of
2,6-diformyl-4-methylphenol, PꢀN, (DME)NiCl2 and
triethylamine (molar ratio = 1:2:2:1) in dry methanol
under nitrogen at 55 ꢁC resulted in the formation of
the corresponding Schiff base-phosphine mono nickel
complex 2 instead of the anticipated dinuclear nickel
complex (Eq. (2)). Recrystallization of the crude product
from dichloromethane and hexane gave complex 2 in the
crystalline form. The chemical shift at 39.7 ppm of com-
plex 2 in 31P NMR was determined due to the phospho-
nium group. The formation of benzo-azaphospholium
ring might be due to the Lewis acid nature of nickel
ion. No 31P NMR signal was observed for the phospho-
rus coordinated to the nickel center, which might be due
to the paramagnetic nature of nickel ion. This is in
agreement with the literature known mononuclear nickel
complexes of PNO donor ligands [6a]. The NH proton
was observed as a doublet at 8.76 ppm (JP–H = 2.4
Hz) and was confirmed by the D2O exchange. The imino
proton appeared to be a singlet at 8.41 ppm. The two
aromatic protons of the phenol are observed as doublets
at 8.22 (0.8 Hz) and 8.19 (0.8 Hz) ppm. The proton on
the carbon of aza-phosphonium ring was observed as
a doublet at 6.32 ppm (1.2 Hz) due to the phosphorus
coupling. FAB mass spectrum shows the isotope pattern
at m/z 775 for the cation part of the complex 2.
Fig. 2. Molecular structure of complex 2.
Table 1
˚
Selected bond lengths (A) and bond angles (ꢁ) of 2
Ni(1)–O(1)
Ni(1)–P(1)
C(7)–N(1)
P(2)–C(9)
Ni(1)–N(1)
Ni(1)–Cl(1)
C(9)–N(2)
1.866(3)
2.1262(10)
1.316(5)
1.853(4)
1.885(3)
2.1861(11)
1.460(5)
O(1)–Ni(1)–N(1)
N(1)–Ni(1)–P(1)
N(1)–Ni(1)–Cl(1)
O(1)–Ni(1)–P(1)
O(1)–Ni(1)–Cl(1)
P(1)–Ni(1)–Cl(1)
95.83(12)
87.63(9)
174.96(9)
175.19(9)
89.20(9)
87.33(4)

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S.R. Korupoju et al. / Inorganica Chimica Acta 358 (2005) 3003–3008
longer than all other P–C bonds in the complex. The dis-
˚
tance of C(9)–N(2) [1.46(5) A] determines the single
bond nature of that bonding, compared to the imine
˚
C(7)–N(1) distance [1.316(5) A]. It is interesting to note
OH
+
O
O
(COD)PdMeCl
O
N
P
O
that even though the N–Hꢂ ꢂ ꢂO interactions are very
strong, the steric bulky benzo-azaphospholium group
is arranged towards the nickel complex instead of NH
group.
H2N
Pd
Me
Ph2P
Ph2
4
ð4Þ
2.3. Palladium(II) complexes
In contrast to the nickel complex, the di-palladium
complex 3 can be easily obtained by the substitution
of COD from (COD)PdMeCl with L3 in a dichloro-
methane solution. Recrystallization of 3 from dichloro-
methane/hexane gave the resulting complex as an
air-stable, light yellowish crystalline complex. The 31P
NMR spectrum showed a singlet absorption at 34.31
ppm corresponding to the coordination of phosphine
toward palladium center. The 1H NMR spectrum
exhibited a doublet at 0.76 (1.6 Hz) ppm correspond-
ing to the CH3 group bonded to the palladium metal
ion in trans arrangement to the imine donor. The
13C NMR absorption at ꢁ1.47 ppm is in agreement
with Pd–CH3 moiety, consistent to the literature
known complexes [4]. Owing to the influence of chlo-
ride groups on the palladium, the aryl protons of the
phenol group shift to downfield from 7.72 to 8.86
ppm.
O
N
P
Pd
Me
Ph2
5
3. Conclusion
Through this study, it was found that the imino-phos-
phine readily underwent cyclization to form the benzo-
azaphospholium moiety via the nucleophilic attack of
phosphine toward imine functionality under acidic con-
ditions. Although donor atoms of ligand L3 are ready
for coordination of two metal ions to form the dinuclear
species, the cyclization still takes place prior to the
complexation with the use of nickel ions, indicating
the Lewis acidic character of nickel ions. In contrast
to nickel complexes, the coordination of (COD)PdMeCl
toward L3 allows to yield the desired bi-metallic species.
The construction of multi-metal complexes with
PNO-donors is currently under investigation.
OMe
(COD)PdMeCl
N
P
N
Cl Cl
MeMe
3
ð3Þ
L3
Pd
Pd
P
Ph2
4. Experimental
Ph2
4.1. General
Interestingly, condensation of 2,6-diformyl-4-methyl-
All reactions, manipulations and purification steps
were performed under a dry nitrogen atmosphere. Tetra-
hydrofuran was distilled under nitrogen from sodium
benzophenone ketyl. Dichloromethane and acetonitrile
were dried with CaH2 and distilled under nitrogen. Other
chemicals and solvents were of analytical grade and were
used as received unless otherwise stated. 2,6-Diformyl-4-
methylphenol [12] and 2-(diphenylphosphino)aniline [13]
were synthesized from the reported procedures.
Nuclear magnetic resonance spectra were recorded in
CDCl3 on either a Bruker AM-300 or AVANCE-400
spectrometer. Chemical shifts are given in parts per mil-
lion relative to Me4Si for 1H and relative to 85% H3PO4
for 31P NMR. Mass spectra were obtained from a Joel
JMSD-300 instrument. FT-IR spectra were recorded
on Nicolet Magna-IR 550 spectrometer (series II) as
KBr pellets. Elemental analyses were carried out using
phenol with 2-(diphenylphosphino)-aniline in the pres-
ence of Pd(COD)MeCl in dry methanol under basic
conditions at 55 ꢁC provided the one side Schiff base
complex 4 in low yields. The FT-IR spectral absorptions
at 1660 and 1616 cmꢁ1 show clearly the presence of both
the aldehyde and imine functional groups, respectively,
1
in the complex along with the support of H NMR sig-
1
nals at 10.75 and 8.85 ppm. The H NMR spectrum
showed the Pd–CH3 absorption at 0.7 ppm correspond-
ing to the trans arrangement of the methyl group to the
imine functionality. The 31P NMR show the coordi-
nated phosphorus signal at 43.71 ppm. Overall, the spec-
tral data of 4 are quite similar to that of 5 [4], which
allow us to assign the structure of 4 properly. Further
reaction of 4 with PꢀN provided the complicated prod-
uct distribution, from which we have not isolated any
pure form.

S.R. Korupoju et al. / Inorganica Chimica Acta 358 (2005) 3003–3008
3007
Perkin–Elmer 240C instrument. FAB mass spectra were
recorded using Jeol JMSD-300 spectrometer.
room temperature for 1.5 h. The resulting light orange
solution was concentrated under vaccum and the solid
obtained was washed with hexane. Recrystallization
from dichloromethane and hexane obtained light blue
crystals and orange crystals. Spectral characterization
of the orange crystals shows Ni(DME)Cl2 compound,
while the blue crystals showed the formation of the com-
4.2. Synthesis and characterization
4.2.1. Preparation of L1 and L4
A dry toluene (10 ml) solution of 2,6-diformyl-4-
methylphenol (0.164 g, 1 mmol) was added to 2-(diph-
enylphosphino)aniline (0.553 g, 2 mmol), and 1 drop of
conc. HCl under dry nitrogen atmosphere and stirred
at room temperature for about 3 h. The reaction is mon-
itored by 31P NMR spectra. The resulting orange solu-
tion was concentrated and washed with hexane several
1
plex 1. Yield: 0.160 g, 28%. H NMR (CDCl3/CD3OD)
d: 1.42 (s, 3H, Ar–CH3), 3.11 (s, 3H, OCH3), 6.32 (s, 1H,
CH), 6.50 (m, 1H, CH), 6.69 (m, 1H, Ar), 6.87 (s, 1H,
Ar), 7.06 (s, 4H, Ar), 7.20 (m, 8H, Ar), 7.51 (m, 8H,
Ar), 7.69 (m, 2H, Ar), 7.82 (m, 4H); 31P NMR d: 41.2;
Anal. Calc. for C46H40Cl4N2OP2Ni: C, 61.44; H, 4.48;
N, 3.12. Found: C, 61.84; H, 4.57; N, 3.00%.
times. Yield: 0.38 g, 53%. FT-IR (KBr, cmꢁ1): (mC@N
)
1
1624; H NMR (CDCl3) d: 2.04 (s, 3H, Ar–CH3), 6.77–
7.67 (m, Ar), 8.32 (s, 1H, C@N); 31P NMR d: ꢁ14.8,
36.8 ppm. Anal. Calc. for C45H37ClN2OP2: C, 75.15;
H, 5.19; N, 3.90. Found: C, 74.89; H, 5.01; N, 3.66%.
L4 was obtained via the similar procedure by running
the reaction in dichloromethane: (31%): 1H NMR
(CDCl3/CD3OD) d: 1.40 (s, 3H, Ar–CH3), 6.43 (s, 2H,
CH), 6.67 (m, 1H, CH), 6.75 (m, 2H, Ar), 6.93 (m,
2H, Ar), 7.19 (s, 4H, Ar), 7.30 (m, 8H, Ar), 7.50 (m,
8H, Ar), 7.72 (m, 2H, Ar), 7.89 (m, 4H, Ar); 31P NMR
d: 38.9; Anal. Calc. for C45H38Cl2N2OP2: C, 71.53; H,
5.07; N, 3.71. Found: C, 71.22; H, 4.67; N, 3.52%.
4.2.4. Complex 2
2,6-Diformyl-4-methylphenol (0.082 g, 0.5 mmol) in
20 ml dry methanol was added to anhydrous (DME)-
NiCl2 (0.220 g, 1 mmol) and 2-(diphenylphosphino)ani-
line (0.277 g, 1 mmol), Et3N (0.050 mg, 0.5 mmol) and
the reaction mixture was heated to 55 ꢁC for 2 h. The
resulting solution was concentrated and the solid was
washed with ether, dried under vacuum. Recrystalliza-
tion from dichloromethane and hexane gave the crystals
suitable for X-ray analysis. Yield: 0.300 g, 52%. FT-IR
(KBr, cmꢁ1): (mC@N) 1623; H NMR (CDCl3) d: 2.04
1
(s, 3H, Ar–CH3), 6.29 (d, J = 1.2 Hz, 1H, CH), 6.91 (t,
J = 4 Hz, 2H, Ar), 7.07 (t, J = 4 Hz, 2H, Ar), 7.22 (m,
J = 8 Hz, 2H, Ar), 7.36 (m, 8H, Ar), 7.53 (q, J = 8 Hz,
8H, Ar), 7.65 (q, J = 8 Hz, 2H, Ar), 7.84 (d, J = 8 Hz,
4H, Ar), 8.17 (q, J = 8 Hz, 2H, Ar), 8.41 (s, 1H,
HC@N), 8.70 (d, JNH–P = 2.4 Hz, NH); 31P NMR
(CDCl3) d: 39.41; FAB mass: m/z 775 [Ni(L4)Cl]+. Anal.
Calc. for C45H35N2O2P2NiCl2: C, 66.68; H, 4.48; N,
3.46. Found: C, 66.44; H, 4.68; N, 2.99%.
4.2.2. Synthesis of 2,6-bis[(o-diphenylphosphino)-
benzeneimino]-4-methylanisole (L3)
A dry toluene (10 ml) solution of 2,6-diformyl-4-
methylanisole (0.656 g, 4 mmol) was added to 2-(diph-
enylphosphino)aniline (2.21 g, 8 mmol), and 1 drop of
conc. HCl under dry nitrogen atmosphere and stirred
at room temperature for about 6 h. The resulting lemon
yellow solution was diluted with dichloromethane and
treated with aq. NaHCO3 solution. The organic layer
was dried over MgSO4 and concentrated. Recrystalliza-
tion from CH2Cl2 and hexane afford to the desired
compound as lemon yellow crystals. Yield: 2.00 g,
70%. FT-IR (KBr, cmꢁ1): (mHC@N) 1617; 1H NMR
(CDCl3) d: 2.28 (s, 3H, Ar–CH3), 3.35 (s, 3H, OCH3),
6.86 (q, J = 7.6 Hz, 2H, Ar-H), 7.02 (q, J = 7.6 Hz,
2H, Ar), 7.14 (t, J = 7.6 Hz, 2H, Ar–H), 7.28–7.40 (m,
22H, Ar), 7.72 (s, 2H, Ar), 8.43 (s, 2H, C@N); 13C
NMR (CDCl3, 25 ꢁC) d: 20.6 (Ar–CH3), 64.8 (OCH3),
117.1, 125.9, 128.2, 128.3, 128.5, 128.7, 129.7, 131.6,
132.5, 132.5, 132.6, 134.0, 134.2, 136.7, 136.8, 154.3,
154.5 (C–O), 154.8 (C–N), 159.1 (C@N); 31P NMR d:
ꢁ16.11 ppm; FAB mass: m/z, 697.3 [M]+. Anal. Calc.
for C46H38N2OP2: C, 79.30; H, 5.50; N, 4.02. Found:
C, 79.25; H, 5.77; N, 3.93%.
4.2.5. Complex 3
Pd(COD)MeCl (0.265 g, 1 mmol) was added to a solu-
tion of L3 (0.348 g, 0.5 mmol) in dry dichloromethane (10
ml) under nitrogen and the mixture was stirred at room
temperature for 1 h. The resuting light yellow solid was
filtered and washed repeatedly with hexane and ether
and dried under vaccum. Recrystallization from
CH2Cl2/hexane gave 3 as crystalline solids. Yield: 0.545
g, 89%. FT-IR (KBr, cmꢁ1): (mC@N) 1624; 1H NMR
(CDCl3/CD3OD) d: 0.76 (d, 6H, J = 1.6 Hz, Pd–CH3),
2.49 (s, 3H, Ar–CH3), 3.74 (s, 3H, OCH3), 7.11 (t, J = 2
Hz, 2H, Ar–H), 7.31 (t, J = 2 Hz, 2H, Ar–H), 7.33–7.52
(m, 22H, Ar), 7.57 (t, J = 2 Hz, 2H, Ar–H), 8.87 (s, 2H,
Ar–H), 8.92 (s, 2H, C@N); 13C NMR d: ꢁ1.47 (Pd–
CH3), 20.9 (Ar–CH3), 65.3 (OCH3), 118.9, 119.0, 127.0,
128.2, 128.7, 129.0, 129.4, 129.5, 131.2, 131.7, 131.9,
132.9, 132.9, 133.0, 133.6, 133.8, 133.9, 136.3, 156.3,
164.7(C@N); 31P NMR d: 34.3. FAB mass: m/z 1018
[M]+. Anal. Calc. for C48H44Cl2N2OP2Pd2: C, 57.05; H,
4.39; N, 2.77. Found: C, 56.89; H, 4.41; N, 2.94%.
4.2.3. Complex 1
(DME)NiCl2 (0.220 g, 1 mmol) was added to a solu-
tion of L3 (0.348 g, 0.5 mmol) in dry dichloromethane
(10 ml) under nitrogen and the mixture was stirred at

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S.R. Korupoju et al. / Inorganica Chimica Acta 358 (2005) 3003–3008
4.2.6. Complex 4
kappa CCD diffractometer with graphite-monochro-
˚
A mixture of 2,6-diformyl-4-methylphenol (0.082 g,
0.5 mmol), (COD)PdMeCl (0.265 g, 1 mmol), and 2-
(diphenylphosphino)aniline (0.277 g, 1 mmol) in 20 ml
dry methanol and Et3N (0.5 mmol) was heated to 55 ꢁC
with stirring for 2 h. The resulting solution was concen-
trated and the solid was washed with ether, dried under
vacuum. Recrystallization from dichloromethane and
hexane gave 4 as light yellow crystalline solids. Yield:
mated Mo Ka radiation (k = 0.071073 A). All the struc-
tures were solved by direct methods (SHELXTL) and all of
the non-hydrogen atoms refined anisotropically. Struc-
tural refinements were done by full-matrix least-squares
methods on F2. Absorption corrections were done using
multi-scan methods. Crystal data for complexes are
listed in Table 2.
Crystallographic data (excluding structure factors)
for the structure reported in this work have been depos-
ited with the Cambridge Crystallographic Data Center:
CCDC-250230 for 1 and CCDC-250231 for 2. Copies
of this information can be obtained free of charge and
by application to CCDC, 12 Union Road, Cambridge
CB2 1EZ, UK (fax: +44 1223 336 033; e-mail: deposit@
ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk).
0.080 g, 13%. FT-IR (KBr, cmꢁ1): (mC@O) 1660, (mC@N
)
1
1623. H NMR (CDCl3) d: 0.70 (s, 3H, Pd–CH3) 2.24
(s, 3H, Ar–CH3), 7.26 (m, 1H, Ar), 7.32 (s, 1H, Ar),
7.33–7.55 (m, 8H, Ar), 7.61–7.66 (m, 4H, Ar), 7.73–
7.76 (m, 1H, Ar), 7.80 (s, 1H, Ar), 8.85 (s, 1H, HC@N),
10.75 (s, 1H, HC@O). 13C NMR (CDCl3) d: ꢁ0.80 (d,
J = 1.2 Hz, Pd–CH3), 19.95 (Ar–CH3), 115.81, 122.67,
123.46, 127.69, 127.79, 128.74, 128.85, 129.05, 129.84,
130.39, 130.93, 131.09, 131.12, 132.67, 133.22, 133.64,
133.86, 136.58, 144.04, 153.81, 154.00, 157.57, 169.61
(C@N), 192.03 (C@O); 31P NMR d: 43.71; FAB mass:
m/z 543.0 [M]+. Anal. Calc. for C28H24NO2 PPd: C,
61.83; H, 4.45; N, 2.58. Found: C, 61.91; H, 4.62; N,
2.60%.
Acknowledgments
We thank the National Science Council, Taiwan,
ROC for the financial support.
4.3. X-ray crystallographic analysis
References
Crystals suitable for X-ray determination were ob-
tained for 1 and 2 Æ CH3OH Æ 2H2O by the slow diffusion
of the hexane into the dichloromethane/methanol solu-
tion of the complexes at room temperature. The cell
parameters were determined at 298 K using a Nonius
[1] A.L. Gavrilova, B. Bosnich, Chem. Rev. 104 (2004) 349, and
references cited therein.
[2] (a) For recent reviews, see P. Braunstein, F. Naud, Angew.
Chem., Int. Ed. 40 (2001) 680;
´
(b) M. Gomez, G. Muller, M. Rocamora, Coord. Chem. Rev.
193–195 (1999) 769;
(c) C.S. Slone, D.A. Weinberger, C.A. Mirkin, Prog. Inorg.
Chem. 48 (1999) 233;
Table 2
Crystallographic data of complexes 1 and 2
(d) P. Espinet, K. Soulantica, Coord. Chem. Rev. 193–195 (1999)
499;
Complex
1
2
(e) G. Helmchen, A. Pfaltz, Acc. Chem. Res. 33 (2000) 336.
[3] F. Speiser, P. Braunstein, L. Saussine, R. Welter, Organometallics
23 (2004) 2613, and references cited therein.
Formula
C
899.27
46H40Cl4N2OP2Ni C46H36Cl2N2O5P2Ni
888.33
Formula weight
Crystal system
Space group
monoclinic
P21
monoclinic
P21/n
[4] P.-Y. Shi, Y.-H. Liu, S.-M. Peng, S.-T. Liu, Organometallics 21
(2002) 3203.
˚
a (A)
11.8110(2)
15.8030(2)
12.0330(2)
90
14.2020(10)
19.2730(10)
15.9530(10)
90
[5] J.R. Dilworth, S.D. Howe, A.J. Hutson, J.R. Miller, J. Silver,
R.M. Thompson, M. Harman, M.B. Hursthouse, J. Chem. Soc.,
Dalton Trans. (1994) 3553.
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
[6] (a) J. Parr, A.M.Z. Slawin, Inorg. Chim. Acta 303 (2000) 116;
(b) P. Bhattacharyya, J. Parr, A.M.Z. Slawin, J. Chem. Soc.,
Dalton Trans. (1998) 3609.
106.1280(10)
90
102.7460(10)
90
3
˚
V (A )
2157.56(6)
2
1.384
4258.97(5)
4
1.385
[7] P. Bhattacharyya, M.L. Loza, J. Parr, A.M.Z. Slawin, J. Chem.
Soc., Dalton Trans. (1999) 2917.
Z
Dcalc (Mg/m3)
F(000)
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B.L. Feringa, Organometallics 17 (1998) 636.
[9] P.-Y. Shi, Y.-H. Liu, S.-M. Peng, S.-T. Liu, J. Chin. Chem. Soc.
50 (2003) 89.
928
1832
Crystal size (mm)
h Range (ꢁ)
Number of reflections
collected
0.20 · 0.15 · 0.10
2.14–25.07
12849
0.30 · 0.25 · 0.20
1.68–25.00
83163
[10] K. Rajender Reddy, W.-W. Tsai, K. Surekha, G.-H. Lee, S.-M.
Peng, J.-T. Chen, S.-T. Liu, Dalton Trans. (2002) 1776.
[11] S. Doherty, J.G. Knight, T.H. Scanlan, M.R.J. Elsegood, W.
Clegg, J. Organomet. Chem. 650 (2002) 231.
Number of independent 7115
reflections
7479
Refined method
full-matrix least-
full-matrix least-
squares on F2
0.0643
[12] R.R. Gagne, C.L. Spiro, T.J. Smith, W.R. Hamann, W.R. Thies,
A.K. Shiemke, J. Am. Chem. Soc. 103 (1981) 4073.
[13] M.K. Cooper, J.M. Downes, P.A. Duckworth, Inorg. Synth. 25
(1989) 129.
squares on F2
0.0506
1.120
R [I > 2r(I)]
Goodness-of-fit on F2
1.076