Synthesis and X-ray structure of cationic β-diimine palladium complexes containing π-methallyl ligand

Article abstract of DOI:10.1016/j.jorganchem.2004.10.003

High yield of cationic palladium β-diimine complexes [(CH ₂(MeCNAr)₂)Pd(η³-C₄H ₇)][Y] (Ar = C₆H₅, Y = PF₆ (8); 2-Me-C₆H₄, Y = PF₆ (9); 2,6-Me ₂-C₆H₃, Y = PF₆ (10); 2,6-iPr ₂-C₆H₃, Y = PF₆ (11), Y = B(3,5-(CF₃)₂-C₆H₃)₄ (12)) have been obtained by an oxidative addition of the methallyloxyphosphonium salts (5, 6) to a preformed complex Pd(dba)₂ (7) in the presence of the β-iminoamine ligands (1-4). These complexes are thermally stable and have been characterized by ¹H and ¹³C{¹H} NMR as well as IR spectroscopy. The structure of the cationic allyl palladium complex (12) has been solved by X-ray crystallography.

Full text of DOI:10.1016/j.jorganchem.2004.10.003

Journal of Organometallic Chemistry 690 (2005) 513–518
www.elsevier.com/locate/jorganchem
Synthesis and X-ray structure of cationic b-diimine
palladium complexes containing p-methallyl ligand
a
Kamel Landolsi , Philippe Richard , Faouzi Bouachir
b
a,
*
a
´
Laboratoire de chimie de coordination, Faculte des Sciences de Monastir, Avenue de lꢀEnvironnement, 5000 Monastir, Tunisia
` ` ´ ´
Laboratoire de Synthese et Electrosynthese Organometalliques, UMR 5188 CNRS-Universite de Bourgogne,
b
9 avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France
Received 15 May 2004; accepted 4 October 2004
Abstract
High yield of cationic palladium b-diimine complexes [(CH2(MeCNAr)2)Pd(g3-C4H7)][Y] (Ar = C6H5, Y = PF6 (8); 2-Me-C6H4,
Y = PF6 (9); 2,6-Me2-C6H3, Y = PF6 (10); 2,6-iPr2-C6H3, Y = PF6 (11), Y = B(3,5-(CF3)2-C6H3)4 (12)) have been obtained by an
oxidative addition of the methallyloxyphosphonium salts (5, 6) to a preformed complex Pd(dba)2 (7) in the presence of the b-imi-
noamine ligands (1–4).
1
These complexes are thermally stable and have been characterized by H and 13C{1H} NMR as well as IR spectroscopy. The
structure of the cationic allyl palladium complex (12) has been solved by X-ray crystallography.
ꢀ 2004 Published by Elsevier B.V.
Keywords: Palladium; Cationic methallyl complexes; b-diimine ligands; Methallyloxyphosphonium salts
1. Introduction
of this anion as non-reactive entity [9]. In addition to the
recognized requirements for weakly coordinating anions,
an effective counteranion must necessarily be chemically
robust and exceptionally resistant to electrophilic attack.
In regard to this, (fluoroaryl)borate are worthy of atten-
tion. However, as the preparation of such anion is costly
and involves significant synthetic effort. New methallyl-
oxyphosphonium salts with the bulky and weakly coordi-
nating anion tetrakis[3,5-bis(trifluoromethyl)phenyl]
borate have been investigated in the hope of generating
electrophilic cationic species.
On the other hand, the use of anionic b-diiminate as
supporting ligand systems in both main and transition
metal coordination chemistry has recently attracted con-
siderable attention [10–29]. These ligands have several
attractive features, including the possible tunability in
both the Ar and R groups as well as variable binding
modes ranging from purely r to a combination of r
and p donation and depending on the steric environ-
ment and the electron demand at the bound metal
Cationic, g3-allyl complexes of palladium(II) prepared
either in situ, or separately, have been reported to catalyse
the dimerization of functionalized alkenes, the oligomeri-
zation of monoolefins [1,2], and the telomerization of ole-
fins with alcohols [3]. In addition much attention has been
paid to these compounds as a result of their importance as
intermediate in palladium catalyzed allylic substitution
reactions. Attack of a nucleophile moiety on a cationic
palladium p-allyl complex is nowdays conventionally ac-
cepted as the crucial step in the catalytic cycle [4–6].
The lack of reactivity and non-nucleophilic character
of [PF6]ꢀ have led to its widespread use as non coordinat-
ing (or weakly coordinating) counterion supporting
cationic organometallic complexes [7,8]. Sufficiently elec-
trophilic complexes of [PF6]ꢀ present reactivity limitation
*
Corresponding author. Tel.: +2162500274; fax: +216 73 500 278.
E-mail address: Faouzi.Bouachir@fsm.rnu.tn (F. Bouachir).
0022-328X/$ - see front matter ꢀ 2004 Published by Elsevier B.V.
doi:10.1016/j.jorganchem.2004.10.003

514
K. Landolsi et al. / Journal of Organometallic Chemistry 690 (2005) 513–518
[15,30]. However complexes in which the ligand is bound
as a neutral donor (b-iminoamine) still remain relatively
unexplored.
a one pot synthesis of new g3-allyl cationic complexes
of palladium (II) bearing variable N,N0-disubstituted
b-diimine ligands which lead to coordination of palla-
dium by two hard donor atoms.
These compounds [(CH2(MeCNAr)2)Pd(g3-C4H7)]+,
which are isolated as stable [PF6]ꢀ and [B(3,5-(CF3)2-
C6H3)4]ꢀ salts, can be easily obtained in high yields by
an oxidative addition of methallyloxyphosphonium salts
[35,36] 5 and 6 to the zerovalent compound Pd(dba)2
[37] 7 in methylene chloride in the presence of a b-imino-
amine ligand [24,25,30] (Scheme 2).
The new complexes 8–11 which are soluble in methyl-
ene chloride and sparingly soluble in chloroform and
diethyl ether gave satisfactory analysis and were charac-
terized by 1H, 13C{1H} NMR and IR spectroscopy. Spe-
cial attention is given to the enhancement of the solubility
and stability of the new cationic complex 12 in relatively
apolar solvents through the use of the fluorine-substituted
tetraarylborate anion [B(3,5-(CF3)2-C6H3)4].
Recently the b-diimine ligands became more popular
since the discovery by Feldman and Co-workers [31] of
‘‘Brookhart type’’ Ni and Pd polymerization catalysts.
They synthesized the first cationic b-diimine palladium
complex by reaction between a ‘‘b-iminoamine’’ and
[Pd(MeCN)4][BF4]2. The species isolated was a-C metal-
lated, a reflection of the ‘‘soft’’ character of the
palladium centre. The C-palladated diimine was coordi-
nated through its two nitrogen atoms to another palla-
dium centre, and it was unclear as to which of these
was the active centre (Scheme 1).
2. Results and discussion
Our interest in b-diimine ligands was sparkled by
Brookhardtꢀs group 10 alkene polymerization precata-
lysts [32,33], as well as a concurrent renewer interest in
the coordination chemistry of diiminate ligands [10–
30], we synthesized g3-allylic b-diimine complexes of
palladium 8–12 from ‘‘b-iminoamine’’ 1–4 in order to
assess the relative merits of a and b-diimine in the
polymerisation of alkenes.
The NMR data of ligands 1–4 are consistent with the
symmetrical, hydrogen-bridged ‘‘b-iminoamine’’ struc-
ture shown in Scheme 2 [30], although complexes 8–12
incorporating neutral ligands of this type are coordi-
nated to palladium as a b-diimine tautomer.
1
The H NMR spectra of these compounds show two
resonances signals for the allyl protons (Hsyn and Hanti)
The present work is a continuation of our study in b-
diimine allylic complexes [34]. We describe in this paper
besides of the methyl group. These signals were attrib-
uted considering that in allyl complexes the syn protons
NCMe
MeCN Pd NCMe
Ar
3+
(BF4 )3
H
NCMe
NCMe
Ar
Ar
-
N
N
MeCN
- HBF4
Pd
H
N
2 [Pd(MeCN)4][BF4] 2
Ar = 2,6-(iPr)2C6H3
+
N
Ar
Scheme 1. a-C palladated diimine complex.
R1
N
R1
Me
H3C
H3C
H3C
R2
+
Y-
R2
R2
+
N
N
CH2Cl2 / 25˚C
+
OP(NMe2)3
5, 6
Y-
+
Pd(dba)2
7
Pd
H
Me
R2
- HMPT
- dba
N
H3C
R1
R1
1-4
8-12
-
8: R1 = R2 = H; Y = PF6
9: R1 = H; R2 = CH3; Y = PF6
10: R1 = R2 = CH3; Y = PF6
11: R1 = R2 = iPr; Y = PF6
12: R1 = R2 = iPr ; Y = B(3,5-(CF3)2-C6H3)4
dba = dibenzylideneacetone.
HMPT = Hexamethylphosphotriamide.
Scheme 2. Synthesis of [(g3-C4H7)Pd(H2C(MeCNAr)2)]+[PF6]ꢀ complexes.

K. Landolsi et al. / Journal of Organometallic Chemistry 690 (2005) 513–518
515
Table 1
Crystallographic data and structure refinement for 12
resonate at higher frequencies than the anti protons [38].
Thus the two resonances are located, respectively, at
2.62, 2.48, 2.28, 2.52 and 2.48 ppm for Hanti and at
2.69, 2.53, 2.57, 2.58 and 2.52 ppm for Hsyn for com-
plexes 8–12. In 13C NMR spectra, the allylic carbon
C(6) and C(8) appears at (62.51 and 64.78); (63.55 and
64.66); 63.86, 64.87 and 66.10 ppm, respectively, for
complexes 8–12. The C@N carbon resonates between
176.30 and 181.02 ppm.
Empirical formula
Formula weight
Temperature (K)
Crystal system
C33H49N2Pd Æ BC32H12F24 Æ CH2Cl2
1528.29
110(2)
Triclinic
ꢀ
Space group
Unit cell dimensions
P1
˚
a (A)
12.7937(4)
13.0162(3)
˚
b (A)
˚
c (A)
21.1177(6)
96.409(1)
The IR spectra of both ligands 1–4 exhibit (NH)
absorption bands at 3400–3300 cmꢀ1 which were not
present in the coordinated ligand. The absence of the
m(H–N) stretching frequencies detected in b-iminoamine
ligands confirm that they are indeed b-diimine tautomer.
Moreover, complexes 8–12 exhibit the frequencies of the
corresponding counterions at 827, 832, 831 and (830 and
838 cmꢀ1) for [PF6] and 1162 and 1121 cmꢀ1 for [B(3,5-
(CF3)2-C6H3)4)]. The m(C@N) stretching frequencies of
the free ligands (1643, 1620, 1631 and 1626 cmꢀ1
respectively for ligands 1–4) are different from those
a (ꢁ)
b (ꢁ)
c (ꢁ)
92.190(1)
102.961(1)
3398.35(16)
3
˚
Volume (A )
Z
2
1539
F(000)
D(calc) (g cmꢀ3
)
1.484
Diffractometer
Scan type
Enraf–Nonius Kappa CCD
Mixture of / rotation and x scans
0.71073
˚
Wavelength (A)
Absorption coefficient (mmꢀ1
)
0.459
0.3 · 0.25 · 0.15
0.65
Crystal size (mm3)
ꢀ1
˚
sin(h)/kmax (A
Index ranges
)
coordinated (1652, 1660, 1667, 1663 and 1663 cmꢀ1
,
ꢀ16 6 h 6 16, ꢀ16 6 k 6 16,
ꢀ27 6 l 6 27
respectively, for complexes 8–12).
Absorption correction
RC = Reflections collected
IRC = Independent RC
SCALEPACK
X-ray single-crystal analysis reveals that compound
12 exhibit some interesting features. Suitable prismatic
and yellow single crystals of 12 were obtained by crystal-
lization from CH2Cl2/n-hexane. The complex 12 crystal-
25,131
15,208 [Rint = 0.0612]
8643
Full-matrix least-squares on F2
IRCGT = IRC and [I > 2r(I)]
Refinement method
Data/Restraints/Parameters
R for IRCGT
ꢀ
lizes in the triclinic unit cell P1 group (Table 1).
15,208/0/891
R1a = 0.0551, wR2b = 0.0966
R1a = 0.1306, wR2b = 0.1168
0.972
An ORTEP-plot shown in Fig. 1 confirms the iden-
tity of complex 12. The structure of the complex 12 con-
sists of loosely associated [(g3-C4H7)Pd(NN)] cation
and tetrahedral [B(3,5-(CF3)2-C6H3)4] counteranion
(Fig. 1(a)). The anion [B(3,5-(CF3)2-C6H3)4] adopts a
structure in which the four fluoroaryl groups are tetra-
hedrally bonded to the central boron atom. The [(g3-
C4H7)Pd(NN)]+ cation of 12 adopts the usual slightly
distorted square planar arrangement and this distortion
is illustrated by the N(1)–Pd–N(2) bond angle equal to
90.61(10)ꢁ (Fig. 1(b)). The allyl ligand is bonded
almost symmetrically to the palladium centre
R for IRC
Goodness-of-fitc
Largest difference peak and
0.58 and ꢀ0.64
ꢀ3
˚
hole (e A
)
P
P
P
a
R1 = (||Fo| ꢀ |Fc||)/ |Fo|.
P
P
2
2 1=2
2
b
wR2 ¼½ wðF 2oꢀF c2Þ = ðF 2oÞ ꢁ ;where w¼1=½r2ðF 2oÞþð0:043PÞ ꢁ;
whereP ¼ðMaxðF 2o;0Þþ2ꢂF c2Þ=3.
2
1=2
c
Goodness-of-fit = ½ wðF 2o ꢀ F c2Þ =ðN0 ꢀ NvÞꢁ
.
(C(6),C(7),C(8)) makes an angle of 63.5(3)ꢁ with the pal-
ladium coordinative least-squares plane (N(1),N(2),
C(6),C(8)). The aryl rings C(10–15) and C(22–27) are
tilted out of the (N(1),C(2),C(4),N(2)) least-squares
plane by 72.3(1)ꢁ and 86.1(2)ꢁ, respectively.
˚
˚
(Pd–C(6) = 2.129(4) A and Pd–C(8) = 2.115(4) A. We
note that the Pd–C(allyl) distances are reasonable for
an allyl trans to a ligand of moderate trans influences.
Selected bond lengths and angles are listed in Table 2.
The b-iminoamine ligand is bounded in a symmetric
fashion as the b-diimine tautomer, which acts as a
chelating ligand through its two N atoms. This ligand
forms a six-membered ring with the palladium atom
3. Conclusions
The coordination chemistry of b-diimines has been
found to be markedly different from otherwise identical
a-diimines, as it is significantly more difficult to prepare
stable complexes of a variety of transition metal species.
We have described in the present work a convenient
synthetic procedure for the preparation of a new cati-
onic methallylpalladium complexes supported by b-
diimine ligand with different anion such as [PF6] and
[B(3,5-(CF3)2-C6H3)4]. The application of these com-
pounds in catalytic reactions such as oligomerization
and polymerization of alkenes (ethylene, styrene,
2
˚
with Pd–N(sp ) bond length of 2.106(3) A in agreement
with known values in the literature for related complexes
[33,35,39]. Bond distances within the six-member chelate
ring are consistent with the localized b-diimine structure
drawn in Fig. 1 while the ring itself adopts a boat con-
formation as indicated in Fig. 1(b).
The methyl on the allyl group is slightly tilted out of
the allyl plane by about 12ꢁ as indicated by the torsion
angle of 167.6ꢁ of C(7)–C(6)–C(8)–C(9). The allyl plane

516
K. Landolsi et al. / Journal of Organometallic Chemistry 690 (2005) 513–518
C9
C7
C22
N2
C8
C4
C3
C2
C3
Pd
Pd
C1
C2
C4
N1
C10
C9
B
C7
C6
C6
C8
N1
N2
C5
C22
C10
(a)
(b)
Fig. 1. (a) Perspective ORTEP diagram of 12. Thermal ellipsoids are at 50% probability. Methylene chloride of crystallization and hydrogen atoms
are omitted for clarity. (b) View of the chelate ring in 12. [B(3,5-(CF3)2-C6H3)4] anion, hydrogen atoms and aryl ring are omitted for clarity.
Table 2
ppm and referenced to the residual solvent resonance
relative to TMS. Infrared spectra were recorded on a
Bruker Victor 22 (Golden Gate Technique).
˚
Bond lengths [A] and angles [ꢁ] for 12
Pd–N(1)
Pd–C(6)
Pd–C(8)
2.105(3)
2.129(4)
2.115(4)
1.284(4)
1.458(4)
Pd–N(2)
Pd–C(7)
2.106(3)
2.153(3)
4.2. General procedure for the preparation of [(b-diimine)
Pd(g3-C4H7)]+ Yꢀ complexes
N(1)–C(2)
N(1)–C(10)
N(2)–C(4)
N(2)–C(22)
1.283(4)
1.462(4)
N(1)–Pd–N(2)
N(1)–Pd–C(8)
N(1)–Pd–C(6)
N(1)–Pd–C(7)
C(7)–Pd–C(8)
C(6)–Pd–C(8)
C(2)–N(1)–C(10)
C(2)–N(1)–Pd
C(10)–N(1)–Pd
90.61(10)
167.12(14)
100.58(13)
133.73(13)
38.34(15)
67.87(16)
118.7(3)
In an inert atmosphere, Pd(dba)2 complex (1equiv.)
was dissolved in anhydrous CH2Cl2. Methallyloxyphos-
phonium (C4H7OP+(NMe2)3Yꢀ) and b-iminoamine lig-
ands were added (1 equvi.). The black-red solution
was stirred at room temperature for 24 h. The superna-
tant was separated by filtration through a Celite filter,
and the solvent was removed under vacuum to afford
the oil compound. This was washed with n-hexane
(3 · 15 mL) and dried in vacuum. The solid was crystal-
lized from methylene chloride/diethyl ether solution at
ꢀ20 ꢁC. Yields ranged from 83% and 94%.
N(2)–Pd–C(6)
N(2)–Pd–C(8)
N(2)–Pd–C(7)
C(6)–Pd–C(7)
166.31(14)
100.11(14)
134.10(13)
37.88(14)
C(4)–N(2)–C(22)
C(4)–N(2)–Pd
C(22)–N(2)–Pd
119.0(3)
125.6(2)
115.3(2)
125.6(2)
115.7(2)
propylene. . .) and functional alkenes (methyl acrylate) is
in currently under study.
4.2.1. Example: Synthesis of [(PhNC(Me)CH2C(Me)-
NPh)Pd(g3-C4H7)]þPF ꢀ6 (8)
4. Experimental
Following
the
general
procedure,
from
4.1. General
(PhNC(Me)CHC(Me)NHPh), (0.4 mmol, 0.1 g).
Pd(dba)2 (0.3 g, 0.4 mmol) and 2-methylallyloxyphos-
phonium (0.4 mmol, 0.15 g) was obtained 0.135 g of 7
as a pale yellow solid after crystallization from a mixture
(diethyl ether/CH2Cl2: 1/1).
All manipulations were carried out under an atmos-
phere of dry argon using standard Schlenk techniques.
Diethyl ether was distilled from sodium benzophenone;
methylene chloride and hexane were distilled over
P2O5. Aniline, 2-methylaniline, 2,6-diisopropylaniline
and 2,6-dimethylaniline were distilled from potassium
hydroxide prior to use. Pd(dba)2 methallyloxyphospho-
nium salts and b-iminoamine ligands were prepared
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
Yield 83%. C21H25N2PF6Pd. CH2Cl2 (641.76): Calc.
C, 41.170; H, 4.242; N, 4.373. Found: C, 42.081; H,
4.762; N, 3.973%. IR (Golden Gate): mC@N = 1652
1
cmꢀ1. H NMR (300 MHz, CD2Cl2, 25 ꢁC, d [ppm]):
d = 1.52 (s, 3H, Me (allyl)); 2.41–2.45 (m, 6H, ligand-
Me); 2.62 (s, 2H, H6anti and Ha8nti); 2.69 (s, 2H,
H6syn and H8syn); 3.93 (m, 2H, ligand-CH2); 6.84–7.44
(m, 10H, ArH). 13C-NMR (75.5 MHz, CD2Cl2, 25 ꢁC,
d [ppm]): d = 22.8 (Me (allyl)); 24.98–25.93 (Me on

K. Landolsi et al. / Journal of Organometallic Chemistry 690 (2005) 513–518
517
ligand); 43.55 and 49.61 (CH2 on ligand); 62.51 and
64.78 (C(6) and C(8), CH2 (allyl)); 120.57–143.18 (Caro
and C(7)-allyl); 151.08 (C–N on C6H5); 180.33 and
181.02 (C@N on ligand).
Yields, physical and spectral data of compounds 9–12
are reported below.
on ligand); 2.52 (s, 2H, H6anti and Ha8nti); 2.58 (s, 2H,
H6syn and H8syn); 2.85 (sept, 2H, CH-CH3, JHH = 6.9
Hz); 3.19 (sept, 2H, CH-CH3, JHH = 6.9 Hz); 4.17 (dd,
2H, J = 13.8 Hz, CH2 on ligand); 7.28 (s, 6H, Haro, Aro-
matic H of Ar group); 13C NMR ( 75.5 MHz, CD2Cl2,
25 ꢁC, d [ppm]): d = 22.28 (Me-allyl); 23.37 (Me on iPr
group); 23.58 (Me on iPr group); 23.78 (Me on iPr
group); 24.18 (Me on iPr group); 24.87 (Me on ligand);
28.34 (CH on iPr group); 28.73 (CH on iPr group); 48.20
(CH2 on ligand); 64.87 (C(6) and C(8), CH2 (allyl));
124.409 (p-C on C6H3); 127.37 (o-C on C6H3); 137.04
(m-C on C6H3);137.38 (m0-C on C6H3); 138.35 (C7(al-
lyl)); 147.62 (C–N); 177.08 (C@N on ligand).
4.2.2. [(oꢀCH3-C6H4NC(Me)CH 2C(Me)NC6H4-o-CH 3)-
Pd(g3-C4H7)]þPF 6ꢀ (9)
Yield = 89%. C23H29N2PF6Pd. (584.88): Calc. C,
47.230; H, 5.101; N, 4.790. Found: C, 47.247; H,
5.303; N, 4.139%. IR (Golden Gate): mC@N = 1660
1
cmꢀ1. H NMR (300 MHz, CD2Cl2, 25 ꢁC, d [ppm]):
d = 1.74 (s, 3H, Me (allyl)); 1.98–2.24 (m, 12H, Me on
ligand and o-CH3 on C6H4); 2.48 (s, 2H,
Ha6nti and H8anti); 2.53 (s, 2H, H6syn and H8syn); 3.88–4.11
(m, 2H, ligand-CH2); 6.84–7.18 (m, 8H, ArH). 13C
NMR (75.5 MHz, CD2Cl2, 25 ꢁC, d [ppm]): d = 18.21–
18.55 (Me (allyl)); 23.18 and 24.15 (Me on ligand);
24.36 and 24.46 (o-C on C6H4); 49.73 and 50.12 (CH2
on ligand); 63.55 and 64.66 (C(6) and C(8), CH2 (allyl));
120.51 and 120.84 (p-C on C6H4); 127.35–129.71 (o0-C
and o0-C on C6H4); 131.87–132.06 (m-C and m0-C on
C6H4); 137.33 and 137.79 (C(7)-allyl); 151.02 and
151.67 (C–N on C6H4); 177.07 and 177.21 (C@N on
ligand).
4.2.5. [(2,6-(iPr)2-C6H3NC(Me)CH2C(Me)NC6H3-2,
6-(iPr)2)Pd(g3-C4H7)]+ [B(3,5-(CF3)2C6H3)4]ꢀ (12)
Yield = 91%. C33H49N2Pd Æ BC32H12F24 Æ CH2Cl2
(1528.34): Calc. C, 51.87; H, 4.15; N, 1.83. Found: C,
51.37; H, 3.861; N, 1.88%. IR (Golden Gate):
1
m
C@N = 1663 cmꢀ1). H NMR (300 MHz, CD2Cl2, 25
ꢁC, d [ppm]): d = 1.05 (d, 6H, JHH = 3.3 Hz, CH(CH3)2);
1.10 (d, 6H, JHH = 3.6 Hz, CH(CH3)2); 1.20 (d, 6H,
JHH = 3.3 Hz, CH(CH3)2); 1.25 (d, 6H, JHH = 3.6 Hz,
CH(CH3)2); 1.84 (s, 3H, Me-allyl); 1.96 (s, 6H, CH3
on ligand); 2.48 (s, 2H, H6anti and Ha8nti); 2.52 (s, 2H,
H6syn and H8syn); 2.71 (sept, 2H, CH-CH3, JHH = 3.9
Hz); 3.06 (sept, 2H, CH-CH3, JHH = 3.9 Hz); 3.97 (s,
2H, CH2 on ligand); 7.20–7.64 (s, 6H, Haro, Aromatic
H of Ar group). 13C NMR ( 75.5 MHz, CD2Cl2, 25
ꢁC, d [ppm]): d = 23.02 (Me-allyl); 23.37 (Me on iPr
group); 23.58 (Me on iPr group); 23.78 (Me on iPr
group); 24.18 (Me on iPr group); 24.87 (Me on ligand);
28.34 (CH on iPr group); 28.73 (CH on iPr group); 49.19
(CH2 on ligand); 66.10 (C(6) and C(8), CH2 (allyl));
125.39 and 125.49 (p-C on C6H3); 127.17 (o-C on
C6H3); 137.37 (m-C on C6H3);137.70 (m0-C on C6H3);
139.71 (C7(allyl)); 147.86 (C–N); 176.33 (C@N on lig-
4.2.3. [(2;6-CH3)2-C6H3NC(Me)CH2C(Me)NC6H3-2;6-
(CH3)2)Pd(g3-C4H7)]þPF ꢀ6 (10)
Yield = 92%. C25H33N2PF6Pd. (612.93): Calc. C,
48.880; H, 5.430; N, 4.570. Found: C, 49.140; H,
5.100; N, 4.847%. IR (Golden Gate): mC@N = 1667
1
cmꢀ1. H NMR (300 MHz, CD2Cl2, 25 ꢁC, d [ppm]):
d = 1.91 (s, 3H, H9, Me (allyl); 2.02 (s, 6H, o-CH3);
2.18 (s, 6H, o0-CH3); 2.28 (s, 2H, H6anti and Ha8nti); 2.31
(s, 6H, Me on ligand); 2.57 (s, 2H, H6syn and Hs8yn); 4.3
(dd, 2H, J = 13.8 Hz, CH2 on ligand); 7.07–7.118 (s,
6H, Haro). 13C NMR ( 75.5 MHz, CD2Cl2, 25 ꢁC, d
[ppm]): d = 17.86 (Me (allyl)); 18.06 (Me on ligand);
22.49 (o-Me on C6H3); 23.106 (o0-Me on C6H3); 48.11
(CH2 on ligand); 63.86 (C(6) and C(8), CH2 (allyl));
126.32 (p-C on C6H3); 126.49 (o-C on C6H3); 126.91
(o0-C on C6H2); 128.78 (m-C on C6H3); 129.93 (m0-C
on C6H3); 137.26 (C(7)-allyl); 150.16 (C–N on C6H3);
176.30 (C@N on ligand).
and) Æ [B(3,5-(CF3)2-C6H3)4]ꢀ:
118.17–119.94
127.161 (q, JCF = 104.9 Hz, CF3); 129.39 (q,
(Cp);
1
1JCF = 32.52 Hz, CF3); 161.5 (q, JCB = 49.8 Hz, Cipso).
19F NMR (282 MHz, CD2Cl2): d (referenced to external
C6F6) 63.27 (s, CF3).
1
4.3. X-ray crystallographic study
The X-ray crystallographic study of complex 12 was
carried out on an Enraf–Nonius Kappa CCD diffrac-
tometer (Mo Ka). Data were collected at 110 K for a
range of h up to 27.5ꢁ and this, gave a total of 25,131
4.2.4. [(2; 6-(iPr)2-C6H3NC(Me)CH2C(Me)NC6H3-2; 6-
(iPr)2)Pd(g3-C4H7)]þPF ꢀ6 (11)
Yield = 94%; C33H49N2PF6Pd. (725.15): Calc. C,
54.660; H, 6.810; N, 3.861. Found: C, 54.699; H,
6.471; N, 4.021%. IR (Golden Gate): mC@N = 1663 and
reflections, yielding 15,208 independent values (Rint
=
0.0612). The structure was solved by direct method
and difference Fourier techniques and were refined by
full-matrix last-squares analysis. Refinements were
based on F2 and were carried out using all the data
(SHELXL-97). All of the non-hydrogen atoms were re-
fined anisotropically. One CF3 group of the anion was
1640 cmꢀ1
.
1H NMR (300 MHz, CD2Cl2, 25 ꢁC, d
[ppm]): d = 1.2 (d, 6H, JHH = 6.9 Hz, CH(CH3)2); 1.23
(d, 6H, JHH = 6.9 Hz, CH(CH3)2); 1.32 (d, 6H,
JHH = 6.6Hz, CH(CH3)2); 1.36 (d, 6H, JHH = 6.9 Hz,
CH(CH3)2); 1.94 (s, 3H, Me-allyl); 2.11 (s, 6H, CH3

518
K. Landolsi et al. / Journal of Organometallic Chemistry 690 (2005) 513–518
[11] C.E. Radzewich, M.P. Coles, R.F. Jordan, J. Am. Chem. Soc. 120
(1998) 9384.
found to be disordered over two positions with occupan-
cies of 0.91:0.09. The F atoms of the disordered minor
component were included with a torsional refinement
with Uiso = 1.5Ueq of the carrier carbon atom (C–
[12] B. Qian, D.L. Ward, M.R. Smith, Organometallics 17 (1998)
3070.
[13] B. Qian, W.J. Scanlon, M.R. Smith, D.H. Motry, Organometallics
18 (1999) 1693.
˚
F = 1.33 A). The hydrogen atoms were included in the
[14] L. Kakaliou, W.J. Scanlon, B. Qian, S.W. Baeck, M.R. Smith,
D.H. Motry, Inorg. Chem. 38 (1999) 5964.
model with Uiso(H) = 1.2Ueq(C) or 1.5Ueq(C) for methyl
groups and refined either freely or with a riding mode.
Pertinent crystallographic data are summarized in
Table 1.
[15] M. Rahim, N.J. Taylor, S. Xin, S. Collins, Organometallics 17
(1998) 1315.
[16] R. Vollmerhaus, M. Rahim, R. Tomaszewski, S. Xin, N.J.
Taylor, S. Collins, Organometallics 19 (2000) 2161.
[17] V.C. Gibson, P.J. Maddox, C. Newton, C. Redshaw, G.A. Solan,
A.J.P. white, D.J. Williams, J. Chem. Soc., Chem. Commun.
(1998) 1651.
5. Supplementary material
[18] W.K. Kim, M.J. Fevola, L.M. Liable-Sands, A.L. Rheingold,
K.H. Theopold, Organometallics 17 (1998) 4541.
[19] V.C. Gibson, J.A. Segal, A.J.P. White, D.J. Williams, J. Am.
Chem. Soc. 122 (2000) 7120.
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC no.234943. Copies of this informa-
tion may be obtained free of charge from the Director,
CCDC, 12 Union Road, CB2 1EZ, UK (fax: +44-
1223-336033; e-mail: deposit@ccdc.cam.ac.uk or www:
http://www.ccdc.cam.ac.uk).
[20] A.P. Dove, V.C. Gibson, E.L. Marshall, A.J.P. White, D.J.
Williams, J. Chem. Soc., Chem. Commun. (2001) 283.
[21] B.M. Chamberlain, M. Cheng, D.R. Moore, T.M. Ovitt, E.B.
Lobkovsky, G.W. Coates, J. Am. Chem. Soc. 123 (2001) 3229.
[22] M. Cheng, A.B. Attygalle, E.B. Lobkovsky, G.W. Coates, J. Am.
Chem. Soc. 121 (1999) 11583.
[23] M. Cheng, E.B. Lobkovsky, G.W. Coates, J. Am. Chem. Soc. 120
(1998) 11018.
Acknowledgements
[24] P.H.M. Budzelaar, R. Gelder, A.W. Gal, Organometallics 17
(1998) 4121.
We are grateful to D. R. Igor TKATCHENKO
(Directeur de Recherche, CNRS) for helpful discussion
and generous supports. We thank Dr. Michel PIC-
QUET and Bertrand REBIERE for assistance with
obtaining X-ray data.
[25] P.H.M. Budzelaar, N.N.P. Moonen, R. Gelder, J.M.M. Smits,
A.W. Gal, Eur. J. Inorg. Chem. (2000) 753.
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