Synthesis and X-ray structure of cationic methallyl palladium complexes supported by unsymmetrical β-diimine ligands

Article abstract of DOI:10.1016/j.poly.2007.11.026

Treatment of the unsymmetrical β-iminoamine ligands [PhCN(Ar)CHCNH(Ar)Me] with the zerovalent complex Pd(dba)₂ in the presence of the methallyloxyphosphonium salt, gives high yields of the cationic β-diimine complexes [PhCN(Ar)CH₂CN(

Full text of DOI:10.1016/j.poly.2007.11.026

Available online at www.sciencedirect.com
Polyhedron 27 (2008) 893–897
www.elsevier.com/locate/poly
Synthesis and X-ray structure of cationic methallyl palladium
complexes supported by unsymmetrical b-diimine ligands
Najoua Belhaj Mbarek Elmkacher a, Taha Guerfel b, Igor Tkatchenko c, Faouzi Bouachir a,*
a Laboratoire de Chimie de Coordination, De´partement de Chimie, Faculte´ des Sciences de Monastir, Avenue de l’Environnement, 5019 Monastir, Tunisia
b Laboratoire de Chimie du Solide, De´partement de Chimie, Faculte´ des Sciences de Monastir, Avenue de l’Environnement, 5019 Monastir, Tunisia
c
` `
´ ´ ´
Laboratoire de Synthese et Electrosynthese Organometalliques, Faculte des Sciences Mirandes, 9 Allee Alain Savary, BP 47870, 21078 Dijon Cedex, France
Received 29 July 2007; accepted 16 November 2007
Available online 4 January 2008
Abstract
Treatment of the unsymmetrical b-iminoamine ligands [PhCN(Ar)CHCNH(Ar)Me] with the zerovalent complex Pd(dba)2 in the
presence of the methallyloxyphosphonium salt, gives high yields of the cationic b-diimine complexes [PhCN(Ar)CH2CN(Ar)-
(Me)Pd(g3-C4H7)]+[PF6]ꢀ (Ar = 2-Me-C6H4 (7); 2-MeO-C6H4 (8); 2,6-Me2-C6H3 (9); 2,6-iPr2-C6H3 (10)). All the new complexes have
been characterised by NMR and IR spectroscopy. The structure of the cationic methallyl palladium complex (10) has been solved by
X-ray crystallography.
Ó 2007 Elsevier Ltd. All rights reserved.
Keywords: Palladium; Cationic methallyl complexes; Unsymmetrical b-diimine ligands
1. Introduction
The molecular weights of the polyethylene generated
with (DAD(CH3,CH3))NiBr2 are higher than those formed
using (DAD(H,H))NiBr2. (DAD = 1,4-diazadiene ligands
derived from glyoxal (H,H) and diacetyl (CH3,CH3)). This
may suggest that sterically more hindered nickel center of
the catalytic species derived from (DAD (CH3,CH3))NiBr2
are longer-lived and may suppress termination by associa-
tive olefin exchange of the monomer.
The difference in ligand structure also influences the num-
ber of branches N, which represent the number of methyl
groups per 1000 carbon atoms. This number is higher for
all polymers produced by catalyst (DAD(CH3, CH3))NiBr2
compared to the polymers generated with (DAD(H,H))-
NiBr2 under the same polymerization conditions. Branches
are formed when b-hydride elimination of the growing poly-
mer chain, followed by isomerization, occurs.
Since the first diketiminate complexes appeared in 1968
[1], there has been sporadic use of this ligand class, other-
wise known as diazapentadienyl, vinamidine, b-iminatoa-
minate etc., in many different scenarios [2]. However, the
introduction of diaryl diketiminates possessing extreme
ortho bulk in 1997 [3], followed rapidly by the first demon-
strations of their use as N–N bidentate, monoanionic
ligands of remarkable steric control in 1998 [4], prompted
a relative explosion of effort in the field.
The study of the anionic ligands b-diketiminate for var-
ious main groups or transition metal chemistry has been
explored [5–13], however their uses as a neutral donor have
been paid less attention [3,14–17].
In polymerization, catalyst design both ligand electron-
ics and sterics play important roles in determining the cat-
alyst activity and polymer molecular weight.
Isomerization is possible when the polymer chain at the
nickel center undergoes b-hydride elimination forming an
intermediate olefin hydride complex and the olefin reinserts
in a 2,1-manner into the nickel–hydride bond before inser-
tion of the next monomer takes place. More isomerization
and branching occur if there is less space at the catalytic
*
Corresponding author. Fax: +216 71 704 329.
E-mail address: bouachirf@yahoo.de (F. Bouachir).
0277-5387/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2007.11.026

894
N. Belhaj Mbarek Elmkacher et al. / Polyhedron 27 (2008) 893–897
site. Thus with the sterically more hindered site, higher
branching frequencies are observed [18].
the unsymmetrical diimine backbone and the syn/syn and
anti/anti interconversion due to the dynamic behaviour of
the allyl protons [21].
The cationic methallyl complexes with symmetrical
b-diimine (R1 = R2 = CH3) are excellent catalysts for the
oligomerization of the styrene, they yield 1,3-diphenylbut-
1-ene with selectivity P98%. However cationic methallyl
complexes with a-diimine ligand produce polymer. This
reflects the effect of change of rigidity of the ligand toward
the catalytic activity of the complex [19]. Different chemis-
try can be carried out with subtle changes of steric demand
in the R1 and R2 positions.
The present work is a continuation of our study in
b-diimine allylic complexes. In this paper we describe a
one-pot synthesis of new g3-allyl cationic complexes of pal-
ladium (II) supported by new ligands, the unsymmetrical
b-diimine [20].
Thus the two resonances are located, respectively, at
2.19, 2.09, 2.58, 2.54 ppm for Hanti and at 2.59, 2.39,
2.88, 2.63 ppm for Hsyn for complexes 7–10.
In 13C NMR spectra, the allylic carbon C(11) and C(13)
appears at (62.51 and 64.54); (63.57 and 64.26); (64.41 and
64.94) and (62.33 and 65.72 ppm), respectively, for com-
plexes 7–10.
The imine carbons show two signals between 172 and
177 ppm.
The IR spectrum of compounds 7–10 indicated a shift in
the C@N stretching frequency (1645; 1603, 1641; 1623,
1660 and 1616, 1647 cmꢀ1) relative to the respectively cor-
responding stretching frequency in the free ligands 1–4
(1622; 1622; 1610, 1649 and 1615 cmꢀ1). Moreover, the
C@N stretching frequency appears at low frequency com-
pared with their value for the compounds with the symmet-
rical b-diimine.
2. Results and discussion
These
compounds
[(PhCNAr)CH2(CH3CNAr)Pd-
(allyl)]PF6 which are isolated as stable salts, can be easily
obtained in high yields by an oxidative addition of methal-
lyloxyphosphonium salt 6 to the zerovalent compound
Pd(dba)2 5 in methylene chloride in the presence of a b-
iminoamine ligand (Scheme 1).
Complexes 7–10 exhibit the frequencies of the counter-
ion PF6 at 838, 846, 832 and 837 cmꢀ1
.
ꢀ
X-ray single-crystal analysis reveals that compound 10
exhibits some interesting features compared with the
symmetrical b-diimine complexes. Suitable prismatic and
colourless single crystals of 10 were obtained by crystalliza-
tion from CH2Cl2/n-hexane. Complex 10 crystallizes in the
monoclinic unit cell P21/n group (Table 1).
The new complexes 7–10 which are soluble in methylene
chloride and sparingly soluble in diethyl ether gave satis-
1
factory analysis and were characterized by H, 13C {1H}
NMR and IR spectroscopy.
An ORTEP-plot shown in Fig. 1 confirms the identity of
complex 10.
The NMR data of ligands 1–4 are consistent with the
hydrogen-bridged b-iminoamine structure [20], although
complexes 7–10 incorporating these ligands as a b-diimine
tautomer.
The [(g3-C4H7)Pd(NN)]+ cation of 10 adopts the usual
slightly distorted square planar arrangement and this dis-
tortion is illustrated by the N(1)–Pd–N(2) bond angle equal
to 90.9° (Fig. 1b). We note that this distortion is more
attenuated than in the complex with the symmetrical b-dii-
mine (N(1)–Pd–N(2) = 90.6°).
The 1H NMR spectra of these compounds show two res-
onance signals for the allyl protons (Hsyn and Hanti) which
appear as a multiplet in contrast with the complexes of the
symmetrical b-diimine (R1 = R2 = CH3) which appear as a
singlet [16]. The multiplicity of these signals is explained by
Selected bond lengths and angles are listed in Tables 2
and 3.
Scheme 1. Synthesis of [(g3-C4H7)Pd((PhCNAr)CH2(MeCNAr))]+[PF6]ꢀ complexes.

N. Belhaj Mbarek Elmkacher et al. / Polyhedron 27 (2008) 893–897
895
Table 1
Crystallographic data and structure refinement for 10
Table 2
Selected interatomic distances
˚
Empirical formula
Formula weight
Crystal system
Space group
Z
C38H51F6N2PPd
787.18
monoclinic
P21/n
Bond distances
(A) for 10
Bond distances (A) for
the symmetric complex
(R1 = R2 = CH3)
˚
Pd–N(1)
Pd–N(2)
2.103(1)
2.130(1)
2.091(1)
2.117(1)
2.144(1)
1.263(1)
1.296(1)
1.410(1)
1.478(1)
1.473(1)
1.543(1)
2.105(3)
2.106(3)
2.129(4)
2.115(4)
2.153(3)
1.284(4)
1.284(4)
1.462(4)
1.459(4)
1.509(4)
1.504(4)
4
˚
a (A)
12.495(5)
13.697(5)
22.244(5)
90.000(5)
92.230(5)
90.000(5)
3804(2)
Pd–C(11)
Pd–C(13)
Pd–C(12)
N(2)–C(3)
C(1)–N(1)
N(2)–C(15)
N(1)–C(27)
C(1)–C(2)
C(3)–C(2)
˚
b (A)
˚
c (A)
a(°)
b (°)
c (°)
3
˚
V (A )
Dcalc (g cmꢀ3
)
1.374
Crystal size (mm3)
Temperature (K)
0.11 ꢁ 0.18 ꢁ 0.25
293(2)
˚
Wavelength (A)
0.71069
F(000)
1632
0.587
Absorption coefficient (mmꢀ1
)
Table 3
Selected angles (°) for 10
h Range for data collection (°)
1.75–27.03
ꢀ15 6 h 6 15, 0 6 k 6 17,
ꢀ2 6 l 6 28
9354/ 8271 [0.1933]
Limiting indices
N (1)–Pd–N(2)
N (1)–Pd–C(13)
C (13)–Pd–N(2)
N (2)–Pd–C(12)
C(11)–Pd–C(12)
C(13)–Pd–C(12)
N(1)–C(1)–C(4)
N(2)–C(3)–C(5)
C(1)–N(1)–C(27)
C(15)–N(2)–Pd
C(27)–N(1)–Pd
C(20)–C(15)–N(2)
C(28)–C(27)–N(1)
C(12)–C(13)–Pd
90.9(4)
166.3(6)
101.2(6)
133.3(6)
37.7(6)
C(11)–Pd–N (1)
101.3(6)
166.3(6)
133.1(6)
66.0(7)
C(11)–Pd–N (2)
N (1)–Pd–C(12)
C(11)–Pd–C(13)
C(11)–Pd–C(12)
C(3)–N(2)–C(15)
N(1)–C(1)–C(2)
N(2)–C(3)–C(2)
C(3)–N(2)–Pd
Reflections collected/unique
[R(int)]
Completeness to h = 27.03
Absorption correction
Maximum and minimum
transmission
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2r(I)]
99.2%
empirical (DIFABS)
0.5729 and 0.1077
37.7(6)
38.2(6)
123.3(1)
123.0(1)
122.0(1)
123.8(1)
123.1(1)
119.3(1)
120.4(1)
73.2(9)
124.5(1)
124.1(1)
120.7(1)
112.8(8)
116.1(8)
119.7(1)
117.4(1)
71.9(9)
full-matrix least-squares on F2
8271/0/433
C(1)–N(1)–Pd
0.941
C(16)–C(15)–N
C(32)–C(27)–N(1)
C(12)–C(11)–Pd
R1 = 0.0907, wR2 = 0.2328
P
P
R1 ¼ ðkF oj ꢀ jF ckÞ= jF oj.
P
P
2
2 1=2
2
wR2 ¼ ½ wðF 2o ꢀ F c2Þ = ðF 2oÞ ꢂ
,
where w ¼ 1=½r2ðF 2oÞ þ ð0:17PÞ ꢂ,
where P ¼ ðF 2o þ 2F c2Þ=3:
The N1–Pd–N2 plane is tilted by 63.74° with regard to
the C11–C12–C13 plane. The methyl on the allyl group is
slightly tilted out of the allyl plane by about 9.1° as indi-
cated by the torsion angle of 170.1° of C(11)–C(12)–
C(13)–C(14). The allyl plane (C(11), C(12), C(13)) makes
an angle of 67.65° with the palladium coordinative least-
square plane (N(1), N(2), C(11), C(13))
If we define a plane containing the Pd and the two nitro-
gen atoms, then the terminal carbons are 0.24 (C11) and
˚
0.25 A (C13) below the plane, whereas the central allyl car-
˚
bon is 0.44 A above.
The allyl ligand is bonded almost symmetrically to the
˚
palladium centre Pd–C(11) = 2.09 A and Pd–C(13) =
˚
2.11 A.
Fig. 1. (a) Perspective ORTEP diagram of the cation of 10. Thermal ellipsoids are at 30% probability. Hydrogen atoms and anion are omitted for clarity.
(b) View of the chelate ring in 10. Hydrogen atoms and aryl ring are omitted for clarity.

896
N. Belhaj Mbarek Elmkacher et al. / Polyhedron 27 (2008) 893–897
The b-iminoamine ligand is bounded in a unsymmetrical
fashion as the b-diimine tautomer, the C(1)–N(1) and
4.2.1. ½ð2-CþH3-C6H4NCðPhÞCH2CðMeÞNC6H4-2-CH3ÞPd
ðg3-C4H7Þꢂ PF6 (7)
ꢀ
˚
˚
C(3)–N(2) distances are 1.29 A and 1.263 A, respectively.
This ligand forms a six-membered ring with the palla-
Following the general procedure, from [2-CH3-C6H4-
NC(Ph)CHC(Me)NHC6H4-2-CH3] (0.059 g, 0.173 mmol),
Pd(dba)2 (0.1 g, 0.173 mmol) and 2-methylallyloxyphos-
phonium (0.173 mmol, 0.065 g) was obtained 0.097 g of 7
as a pale yellow solid after crystallization from a mixture
(CH2Cl2/n-hexane: 1/1).
2
˚
dium atom with Pd–N (sp ) bond length of 2.10 A and
2.13 A in agreement with known values in the literature
˚
for related complexes [15,22–24]. Bond distances within
the six-member chelate ring are consistent with the local-
ized b-diimine structure drawn in Fig. 1, while the ring
itself adopts a boat conformation as indicated in Fig. 1b.
The aryl rings C(15–20) and C(27–32) are tilted out of
the (N(1), C(1), C(3), N(2)) least-square plane by 70° and
69.49°, respectively.
1
Yield 87%. IR (Golden Gate): mC@N = 1645 cmꢀ1. H
NMR (300 MHz, CDCl3, 25 °C, d [ppm]): d = 1.62 (s,
3H, Me (allyl)); 1.79 ( s, 3H Me on ligand); 1.98 (s, 3H,
Me–C6H4); 2.11 (s, 3H, Me–C6H4); 2.19 (m, 2H, H11anti
and H13anti); 2.59 (m, 2H, H11syn and H13syn); 3.83 (m,
2H, ligand–CH2); 6.97–7.42 (m, 13H, ArH). 13C NMR
(75.5 MHz, CDCl3, 25 °C, d [ppm]): d = 14.25 (Me
(allyl));18.85 (Me on C6H4); 19.48 (Me on C6H4); 22.31
(Me on ligand); 49.71 (CH2 on ligand); 62.51 and 64.52
(C(11) and C(13)); 121.37–133.24 (C(ar) and C(12));
138.13 (C–C on C6H5); 148.13 and 150.61 (C–N on
C6H4); 172.45 and 176.25 (C@N on ligand).
3. Conclusion
New cationic methallyl palladium complexes supported
by unsymmetrical b-diimine have been described. The
application of these compounds in catalytic reactions such
as dimerization and polymerization of alkenes and func-
tional alkenes is in current study in order to compare them
with the symmetric ones.
4.2.2. ½ð2-CH3O-C6H4þNCðPhÞCH2CðMeÞNC6H4-2-
ꢀ
CH3OÞ-Pdðg3-C4H7Þꢂ PF6 (8)
4. Experimental
Following the general procedure, from [2-CH3O-
C6H4NC(Ph)CHC(Me)NHC6H4-2-CH3O]
(0.064 g,
4.1. General
0.173 mmol), Pd(dba)2 (0.1 g, 0.173 mmol) and 2-methylal-
lyloxyphosphonium (0.173 mmol, 0.065 g) was obtained
0.104 g of 8 as a pale yellow solid after crystallization from
a mixture (CH2Cl2/n-hexane: 1/1).
All manipulations were carried out under an atmosphere
of dry argon using standard Schlenk techniques.
Diethyl ether was distilled from sodium benzophenone;
methylene chloride and hexane were distilled over P2O5.
2-Methylaniline, 2,6-dimethylaniline, 2-methoxyaniline
and 2,6-diisopropylaniline were distilled from potassium
hydroxide prior to use. Pd(dba)2 [25,26] methallyloxyphos-
phonium salt [27] and b-iminoamine ligands [20] were pre-
pared according to literature methods. All other reagents
were obtained from standard commercial vendors and used
as received. NMR spectra were recorded on a Bruker AC-
300 spectrometer. H and C chemical shifts are given in ppm
and referenced to the residual solvent resonance relative to
TMS. Infrared spectra were recorded on a Bruker Victor 22
(Golden Gate Technique).
Yield = 89%. IR (Golden Gate): mC@N = 1603 and
1
1641 cmꢀ1. H NMR (300 MHz, CDCl3, 25 °C, d [ppm]):
d = 1.81 (s, 3H, Me (allyl)); 2.00 (s, 3H, Me on ligand);
2.09 (m, 2H, H11anti and H13anti); 2.39 (m, 2H, H11syn and
H13syn); 3.65–3.80 (m, 2H, ligand–CH2); 3.85–3.91(m, 6H,
H3CO); 6.77–7.60 (m, 13H, ArH). 13C NMR (75.5 MHz,
CDCl3, 25 °C, d [ppm]): d = 14.18 (Me (allyl)); 22.75 (Me
on ligand); 55.88 (CH3O); 49.95 (CH2 on ligand); 62.33
and 65.72 (C(11) and C(13)); 111.52–130.64 (C(ar) and
C(12)-allyl); 134.44 (C–C on C6H5) 139.58 and 144.42
(C–N on C6H4); 177.07 and 177.21 (C@N on ligand).
4.2.3. ½2; 6-ðCH3Þ -C6H3NCðPhÞCH2CðMeÞNC6H3-
2
þ
2; 6-ðCH3Þ Pdðg3-C4H7Þꢂ PF6 (9)
ꢀ
2
4.2. General procedure forþthe preparation of
Following the general procedure, from [2,6-(CH3)2-
½ðb-diimineÞPdðg3-C4H7Þꢂ PF6 complexes
C6H3NC(Ph)CHC(Me)NHC6H3-2,6-(CH3)2]
(0.063 g,
ꢀ
0.173 mmol), Pd(dba)2 (0.1 g, 0.173 mmol) and 2-methylal-
lyloxyphosphonium (0.173 mmol, 0.065 g) was obtained
0.107 g of 9 as a pale yellow solid after crystallization from
a mixture (CH2Cl2/n-hexane: 1/1).
In an inert atmosphere, Pd(dba)2 complex (1 equiv.) was
dissolved in 20 cm3 anhydrous CH2Cl2. Methallyloxyphos-
phonium salt C4H7OPþðNMe2Þ PF and b-iminoamine
ꢀ
3
6
ligands were added (1 equiv.). The black-red solution was
stirred at room temperature for 24 h. The supernatant
was separated by filtration through a celite filter, and the
solvent was removed under vacuum to afford the oil com-
pound. This was washed with diethyl ether (3 ꢁ 15 cm3)
and dried in vacuum. The solid was crystallized from meth-
ylene chloride/n-hexane solution. Yields and spectral data
of compounds 7–10 are reported below.
Yield 92%. IR (Golden Gate): mC@N = 1623 and
1
1660 cmꢀ1. H NMR (300 MHz, CDCl3, 25 °C, d [ppm]):
d = 0.87 (s, 3H, Me (allyl)); 1.56 (s, 3H, Me on ligand);
1.95 (s, 3H, Me on C6H3); 2.02 (s, 3H, Me on C6H3);
2.19 (s, 3H, Me on C6H3); 2.25 (s, 3H, Me on C6H3);
2.58 (m, 2H, H11anti and H13anti); 2.88 (m, 2H, H11syn and
H13syn); 4.72 (m, 2H, ligand CH2); 6.92–7.26 (m, 11H,
Har). 13C NMR (75.5 MHz, CDCl3, 25 °C, d [ppm]):

N. Belhaj Mbarek Elmkacher et al. / Polyhedron 27 (2008) 893–897
897
d = 14.20 (Me (allyl)); 22.72 (Me on ligand); 18.16, 18.37,
18.82 and 19.19(Me on C6H3); 49.46 (CH2 on ligand);
63.57 and 64.26 (C(11) and C(13)); 126.24–135.68 (C(ar)
and C(12)); 137.21 (C–C on C6H5); 149.84 and 150.51(C–
N on C6H3); 173.73 and 176.54 (C@N on ligand).
Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax:
(+44) 1223-336-033, or e-mail: deposit@ccdc.cam.ac.uk.
Supplementary data associated with this article can be
found, in the online version, at doi:10.1016/j.poly.2007.
11.026.
4.2.4. ½2; 6-ðiPrÞ -C6H3NCðPhÞCH2CðMeÞNC6H3-
2
þ
ꢀ
2; 6-ðiPrÞ Pdðg3-C4H7Þꢂ PF6 (10)
References
2
Following the general procedure, from [2,6-(iPr)2-
C6H3NC(Ph)CHC(Me)NHC6H3-2,6-(iPr)2] (0.083 g, 0.173
mmol), Pd(dba)2 (0.1 g, 0.173 mmol) and 2-methylallyloxy-
phosphonium (0.173 mmol, 0.065 g) was obtained 0.129 g
of 10 as a pale yellow solid after crystallization from a mix-
ture (CH2Cl2/n-hexane: 1/1).
[1] J.E. Parks, R.H. Holm, Inorg. Chem. 7 (1968) 1408.
[2] A recent review L. Bourget-Merle, Michael F. Lappert, J.R. Severn,
Chem. Rev. 102 (2002) 3031.
[3] J. Feldman, S.J. McLain, A. Parthasarathy, W.J. Marshall, J.C.
Calabrese, S.D. Arthur, Organometallics 16 (1997) 1514.
[4] W. Clegg, E.K. Cope, A.J. Edwards, F.S. Mair, Inorg. Chem. 37
(1998) 2317.
Yield = 95%. IR (Golden Gate): mC@N = 1616 and
[5] M. Rahim, N.J. Taylor, S. Xin, S. Collins, Organometallics 17 (1998)
1315.
1
1647 cmꢀ1. H NMR (300 MHz, CDCl3, 25 °C, d [ppm]):
d = 0.88–1.40 (m, 21 H, Me-iPr and Me on allyl); 1.99 (s,
3H, Me on ligand); 2.17 (d, 6H, J = 16.8 Hz, Me-iPr);
2.54 (m, 2H, H11anti and H13anti); 2.63 (m, 2H, H11syn and
H13syn); 3.02 (sept, 2H, J = 7.5 Hz, H-C-iPr); 3.39 (sept,
1H, J = 6.9 Hz, H-C-iPr); 3.76 (sept, 1H, J = 7.2 Hz,
H-C-iPr); 4.66–5.06 (m, 2H, CH2 on ligand); 7.02–7.26
(m, 11H, Har); 13C NMR (75.5 MHz, CDCl3, 25 °C, d
[ppm]): d = 15.87 (Me-allyl); 22.84 (Me on ligand); 23.84,
23.88, 24.00, 24.21, 24.34, 24.38, 24.71 and 25.66 (Me on
iPr group); 28.68, 28.76, 29.20 and 29.43 (CH on iPr
group); 49.91 (CH2 on ligand); 64.41 and 64.9 (C(11) and
C(13)); 124.25–138.08 ( C(ar) and C(12)); 138.23 (C–C on
C6H5); 147.26 and 148.14 (C–N on C6H3); 172.77 and
177.45 (C@N on ligand).
[6] B. Qian, D.L. Ward, N.R. Smith, Organometallics 17 (1998)
3070.
[7] W.K. Kim, M.J. Fevola, L.M. Liable-Sauds, A.L. Rheingold, K.H.
Theopold, Organometallics 17 (1998) 4541.
[8] F. Cosledan, P.B. Hitchcock, M.F. Lappert, Chem. Commun. (1999)
707.
[9] D.L. Reger, S.J. Knox, M.F. Huff, A.L. Rheingold, B.S. Haggerty,
Inorg. Chem. 30 (1991) 1754.
[10] C.F. Caro, P.B. Hitchcock, M.F. Lappert, Chem. Commun. (1999)
1433.
[11] P.B. Hitchcock, M.F. Lappert, S. Tian, J. Chem. Soc., Dalton Trans.
(1997) 1945.
[12] P.B. Hitchcock, M.F. Lappert, M. Layh, D.-S. Liu, R. Sablong, S.
Tian, J. Chem. Soc., Dalton Trans. (2000) 2301 and references quoted
therein.
[13] P.B. Hitchcock, J. Hu, M.F. Lappert, M. Layh, D.-S. Liu, J.R.
Severn, S. Tian, An. Quim. Int., Ed. Engl. 92 (1996) 186.
[14] K. Landolsi, M. Rzaigui, F. Bouachir, Tetrahedron Lett. 43 (2002)
9463.
4.3. X-ray crystallographic study
[15] E.K. Cope-Eatough, F.S. Mair, R.G. Pritchard, J.E. Warren, R.J.
Woods, Polyhedron 22 (2003) 1447.
[16] K. Landolsi, P. Richard, F. Bouachir, J. Organomet. Chem. 690
(2005) 513.
[17] J. Zhang, Z. Ke, F. Bao, J. Long, H. Gao, F. Zhu, Q. Wu, J. Mol.
Catal. A: Chem. 249 (2006) 31.
[18] T. Schleis, T.P. Spaniol, J. Okuda, J. Heinemann, R. Mulhaupt, J.
Organomet. Chem. 569 (1998) 159.
[19] K. Landolsi, F. Bouachir, E. Bouajila, M. Picquet, D. Poinsot, I.
Tkatchenko, in: 1st International Congress on Ionic Liquid, Salz-
burg/Austria, June 19–22, COIL, 2005, p. 28.
[20] K. Landolsi, N. Belhaj Mbarek Elmkacher, T. Guerfel, F. Bouachir,
C.R. Chimie, (2007), doi:10.1016/j.crci.2007.11.005.
[21] Y.-L. Tung, W.-C. Tseng, C.-Y. Lee, P.-F. Hsu, Y. Chi, S.-M. Peng,
G.-H. Lee, Organometallics 18 (1999) 864.
The X-ray crystallographic study of complex 10 was car-
ried out on a CAD4 Enraf-Nonius diffractometer (Mo Ka).
Data were collected at 283 K in the range 1–27° and this
gave a total of 9354 reflections, yielding 8271 independent
values (Rint = 0.1933). The structure was solved by direct
method and difference Fourier techniques and were refined
by full-matrix least-squares analysis. Refinements were
based on F2 and were carried out using all the data (SHEL-
XL-97). All of the non-hydrogen atoms were re-fined aniso-
tropically. The hydrogen atoms were fixed geometrically in
their idealized positions. The set of physical and crystallo-
graphic characteristics as well as the experimental condi-
tions are listed in Table 1.
[22] D.J. Tempel, L.K. Johnson, R.L. Huff, P.S. White, M. Brookhart, J.
Am. Chem. Soc. 122 (2000) 6686.
[23] A. Mechria, M. Rzaigui, F. Bouachir, Tetrahedron Lett. 44 (2003)
6773.
Appendix A. Supplementary material
[24] B. Crociani, R. Bertani, G. Bandoli, J. Chem. Soc., Dalton Trans.
(1982) 1715.
[25] M.F. Rettig, P.M. Maitlis, Inorg. Synth. 17 (1977) 134.
[26] T. Ukai, H. Kawazura, Y. Ishii, J. Bonnet, J.A. Ibers, J. Organomet.
Chem. 65 (1994) 253.
CCDC 272962 contains the supplementary crystallo-
graphic data for 10. These data can be obtained free of
charge via http://www.ccdc.cam.ac.uk/conts/retrieving.
html, or from the Cambridge Crystallographic Data
[27] D. Neibecker, B.J. Castro, J. Organomet. Chem. 134 (1977) 105.