An organometallic compound with Z′ = 4: {2-[2-(benzylideneamino) phenyl]-1,2-bis(methoxycarbonyl)ethenyl-κ2C1,N} iodo(triphenylphosphine-κP)palladium(II)

Article abstract of DOI:10.1107/S0108270106051870

The title compound, [Pd(C₁₉H₁₇NO₄)I(C ₁₈H₁₅P)], crystallizes with four independent molecules in the asymmetric unit. The main difference between the molecules is the disposition of the PPh₃ ligand, for which in each molecule one ring is perpendicular to the ligand plane, but may be directed in either direction away from the plane; of the four molecules, two represent each possible direction. The independent molecules are arranged to form a chain parallel to [101] with an approximate translation of (a+c)/4 between successive molecules, excluding the PPh₃ rings. This leads to a systematic weakness of the reflections with h + l ≠ 4n.

Full text of DOI:10.1107/S0108270106051870

metal-organic compounds
Acta Crystallographica Section C
Crystal Structure
number 2, 3 or 4. In all four molecules, the Pd atom shows the
expected planar four-coordination, albeit with slight but
Communications
ISSN 0108-2701
An organometallic compound with
Z0 = 4: {2-[2-(benzylideneamino)-
phenyl]-1,2-bis(methoxycarbonyl)-
ethenyl-j2C1,N}iodo(triphenyl-
phosphine-jP)palladium(II)
signi®cant deviations from planarity (r.m.s. deviations of the
®ve atoms Pd, I, P, N and C from their least-squares plane are
Ê
0.01, 0.04, 0.05 and 0.08 A, respectively, for molecules 1±4).
The bond lengths at Pd are consistent over all four molecules
(see below for one possible exception). The bite of the C,N-
bidentate ligand is constant at ca 82ꢀ (important molecular
dimensions are given in Table 1). The chelate rings display a
con®guration whereby atoms Pdn, Cn01, Cn02 and Cn12 are
a
b
Â
Â
Peter G. Jones * and Joaquõn Lopez-Serrano ³
aInstitut fur Anorganische und Analytische Chemie, Technische Universitat
È
È
Braunschweig, Postfach 3329, 38023 Braunschweig, Germany, and bGrupo de
Ê
coplanar (r.m.s. deviations ꢁ 0.02 A for all four molecules),
Â
Â
Â
Â
Quõmica Organometalica, Departamento de Quõmica Inorganica, Facultad de
and the other two atoms, Nn and Cn11, are displaced from this
plane to the same side. The double-bond positions
Cn01 Cn02 are unambiguously established by the bond
lengths. The carboxylate groups are disposed such that the
absolute torsion angles Cn02 Cn01ÐCn03 On01 lie in the
range 9±17ꢀ and Cn01 Cn02ÐCn04 On02 in the range 90±
97ꢀ.
Â
Quõmica, Universidad de Murcia, Apartado 4021, 30071 Murcia, Spain
Correspondence e-mail: p.jones@tu-bs.de
Received 29 November 2006
Accepted 30 November 2006
Online 23 December 2006
The title compound, [Pd(C19H17NO4)I(C18H15P)], crystallizes
with four independent molecules in the asymmetric unit. The
main difference between the molecules is the disposition of
the PPh3 ligand, for which in each molecule one ring is
perpendicular to the ligand plane, but may be directed in
either direction away from the plane; of the four molecules,
two represent each possible direction. The independent
molecules are arranged to form a chain parallel to [101] with
an approximate translation of (a+c)/4 between successive
molecules, excluding the PPh3 rings. This leads to a systematic
weakness of the re¯ections with h + l ˆ 4n.
Despite the above-mentioned similarities, the molecules
differ in one important respect, namely the disposition of the
triphenylphosphine ligand. For each molecule, one phenyl ring
of PPh3 is approximately perpendicular to the coordination
plane (cf. torsion angles IÐPdÐPÐCipso in Table 1; in each
Comment
The title compound, (I), was synthesized during a study of aryl
palladium complexes bearing functionalized susbtituents on
the ortho position. In these investigations, oxidative addition
of Pd0 precursors to aryl halides yielded organometallic
compounds that are models of intermediates in palladium-
catalysed organic syntheses (Vicente et al., 2005) and may lead
to new coordination modes for the ligands. There are a large
number of known palladium±diimine complexes; a search of
the Cambridge Structural Database (CSD, Version 5.27; Allen,
2002) revealed 106 hits for ꢀ-diimine complexes of palladium,
e.g. de Pater et al. (2005). However, the double bond in the
imine group of (I) does not form part of the heterocycle.
Compound (I) crystallizes in the solvent-free form with four
independent molecules in the asymmetric unit. Molecules 1
and 3 are shown in Figs. 1 and 2, respectively; a similar
numbering scheme was used for all the molecules, replacing
the ®rst digit `1' in molecule 1 with the appropriate molecule
Figure 1
The ®rst independent molecule of compound (I), showing the atom-
numbering scheme. Displacement ellipsoids are drawn at the 30%
probability level and H atoms are shown as small spheres of arbitrary
radii.
³ Current address: Department of Chemistry, University of York, Heslington,
York YO10 5DD, England.
m16 # 2007 International Union of Crystallography
DOI: 10.1107/S0108270106051870
Acta Cryst. (2007). C63, m16±m18

metal-organic compounds
case, there is one ring with an absolute value of ca 90ꢀ).
However, in molecules 1 and 4, the ring at Cn31 points out of
the coordination plane to the same side as ring Cn11, whereas
in molecules 2 and 3 (Fig. 2), the ring at Cn51 points to the
other side of the plane from Cn11, viz. to the same side as
Cn21. The differing PdÐP bond lengths (slightly longer for
molecules 2 and 3) and the markedly irregular PdÐPÐC bond
angles for molecules 1 and 4, with wide angles of ca 120ꢀ to
Cn41 to avoid closer contact between the phenyl ring and the
methoxycarbonyl group at Cn01, also re¯ect these differences.
Even within this loose classi®cation as two pairs of similar
molecules, there are considerable differences in the IÐPdÐ
PÐC and PdÐPÐCÐC torsion angles for either given pair.
In the CSD, there are 25 examples of palladium complexes
with a coordination sphere of C/N(chelating)/P/I. However,
the bond lengths at Pd vary over a very wide range (e.g.
Ê
PdÐN = 2.09±2.32 A), making generalization dif®cult, and the
iodo ligand may be trans to C or P. There are no examples with
P trans to C for this donor atom set; consistent with the great
extent of P/C `transphobia' (Vicente et al., 1997, 2002, 2006),
the P- and C-atom donors are mutually cis in (I) and in the
other literature examples.
The molecular packing of (I) is noteworthy. The molecules
are associated into chains parallel to [101] (Fig. 3), in which
neighbouring molecules, except for the PPh3 phenyl groups as
noted above, adopt positions related by the non-crystal-
lographic translation of (a+c)/4. This pseudosymmetry is
responsible for the fact that re¯ections with h + l ˆ 4n are
systematically weak. However, the seven non-classical
(`weak') hydrogen-bonding interactions (Desiraju & Steiner,
1999; Table 2), of which ®ve involve para-H atoms of the PPh3
ligands, are not formed within the chains.
Experimental
Under a dinitrogen atmosphere, dimethyl acetylenedicarboxylate
(DMAD) (94 ml, 0.7 mmol) was added to a solution of trans-
[(C6H4N CH2Ph-2)I(PPh3)2Pd] (Vicente et al., 1999) (125 mg,
0.13 mmol) in degassed CH2Cl2 (5 ml) and the reaction mixture was
stirred overnight (16 h). The solvent was removed and the residue
was treated with diethyl ether (5 ml). The solid was collected by
®ltration, washed with diethyl ether (3 Â 3 ml) and dried in air to
yield complex (I) as a yellow powder (yield 80 mg, 73%). Single
crystals were obtained by slow diffusion of Et2O into a solution of
1
complex (I) in CDCl3. IR (Nujol, ꢁ, cm 1): 1726 (CO); H NMR
3
1
(300 MHz, CDCl3): ꢂ 8.70 (d, JH,H = 7 Hz, 2H), 8.40 (d, JH,H
=
13.5 Hz, 1H), 7.68±7.33 (several m, 22H, 4Ph + 2Harom), 3.69 (s, 3H,
OMe), 3.06 (s, 3H, OMe); 31P{1H} NMR (121 MHz, CDCl3): ꢂ 31.44
(PPh3). Analysis calculated for C37H31INO4PPd: C 54.33, H 3.82, N
1.71%; found: C 54.53, H 3.86, N 1.67%.
Figure 2
The third independent molecule of compound (I), showing the atom-
numbering scheme. Displacement ellipsoids are drawn at the 30%
probability level and H atoms are shown as small spheres of arbitrary
radii.
Crystal data
[Pd(C19H17NO4)I(C18H15P)]
Mr = 817.90
Z = 16
Dx = 1.611 Mg m
Mo Kꢀ radiation
ꢄ = 1.55 mm
T = 133 (2) K
Prism, yellow
0.38 Â 0.22 Â 0.20 mm
3
Monoclinic, P21=c
1
Ê
a = 16.6938 (11) A
Ê
b = 22.1074 (15) A
Ê
c = 36.666 (3) A
ꢃ = 94.460 (4)ꢀ
V = 13490.8 (17) A
3
Ê
Data collection
Bruker SMART 1000 CCD area-
detector diffractometer
! and ' scans
Absorption correction: multi-scan
(SADABS; Bruker, 1998)
Tmin = 0.653, Tmax = 0.733
261441 measured re¯ections
39449 independent re¯ections
27970 re¯ections with I > 2ꢅ(I)
Rint = 0.050
ꢆmax = 30.0ꢀ
Re®nement
Re®nement on F2
R[F2 > 2ꢅ(F2)] = 0.030
wR(F2) = 0.070
S = 0.95
39449 re¯ections
1629 parameters
H-atom parameters constrained
w = 1/[ꢅ2(Fo2) + (0.033P)2]
2
where P = (Fo + 2Fc2)/3
Figure 3
The four independent molecules of (I) in the unit cell, running in order
from molecule 1 (bottom right) to molecule 4 (top left). H atoms have
been omitted.
(Á/ꢅ)max = 0.006
3
Ê
Áꢇmax = 1.26 e A
3
Ê
0.90 e A
Áꢇmin
=
ꢂ
Â
Acta Cryst. (2007). C63, m16±m18
Jones and Lopez-Serrano
[Pd(C19H17NO4)I(C18H15P)] m17

metal-organic compounds
Table 1
Selected geometric parameters (A, ).
Table 2
Hydrogen-bond geometry (A, ).
ꢀ
ꢀ
Ê
Ê
Pd1ÐC101
Pd1ÐN1
Pd1ÐP1
2.019 (2)
Pd3ÐC301
Pd3ÐN3
Pd3ÐP3
2.023 (2)
DÐHÁ Á ÁA
DÐH
HÁ Á ÁA
DÁ Á ÁA
DÐHÁ Á ÁA
2.0744 (18)
2.2524 (6)
2.6716 (3)
1.338 (3)
2.0727 (17)
2.2700 (6)
2.6595 (3)
1.344 (3)
C154ÐH154Á Á ÁO401i
C254ÐH254Á Á ÁO402i
C313ÐH313Á Á ÁO302ii
C354ÐH354Á Á ÁO102iii
C454ÐH454Á Á ÁO301iii
C133ÐH133Á Á ÁI3iv
0.95
0.95
0.95
0.95
0.95
0.95
0.95
2.44
2.49
2.42
2.59
2.45
2.99
2.99
3.325 (3)
3.334 (3)
3.170 (3)
3.536 (3)
3.088 (3)
3.805 (3)
3.780 (2)
155
148
136
174
124
145
141
Pd1ÐI1
Pd3ÐI3
C101ÐC102
Pd2ÐC201
Pd2ÐN2
Pd2ÐP2
Pd2ÐI2
C201ÐC202
C301ÐC302
Pd4ÐC401
Pd4ÐN4
Pd4ÐP4
Pd4ÐI4
C401ÐC402
2.020 (2)
2.024 (2)
2.0813 (19)
2.2833 (6)
2.6683 (3)
1.346 (3)
2.0654 (18)
2.2660 (6)
2.6877 (3)
1.347 (3)
C444ÐH444Á Á ÁI1v
Symmetry codes: (i) x ‡ 1; y ‡ 12; z ‡ 21; (ii) x; y ‡ 1; z ‡ 1; (iii) x; y ‡ 12; z
;
1
2
(iv) x; y ‡ 12; z ‡ 21; (v) x 1; y ‡ 12; z
.
1
2
C101ÐPd1ÐN1
C101ÐPd1ÐP1
N1ÐPd1ÐP1
C101ÐPd1ÐI1
N1ÐPd1ÐI1
82.16 (8)
93.37 (6)
165.77 (5)
168.71 (6)
88.46 (5)
C301ÐPd3ÐN3
C301ÐPd3ÐP3
N3ÐPd3ÐP3
C301ÐPd3ÐI3
N3ÐPd3ÐI3
82.01 (8)
91.08 (6)
170.16 (5)
168.52 (6)
87.45 (5)
times Ueq of the parent atom. The maximum residual electron density
3
of 1.3 e A is associated with the methoxy group at C401, and may
Ê
indicate slight disorder of this group. The next ®ve difference peaks
(down to 0.8 e A 3) all lie close to Pd or I atoms.
Ê
P1ÐPd1ÐI1
94.253 (17) P3ÐPd3ÐI3
98.796 (17)
109.98 (7)
118.36 (8)
114.94 (8)
82.05 (8)
C131ÐP1ÐPd1
C141ÐP1ÐPd1
C151ÐP1ÐPd1
C201ÐPd2ÐN2
C201ÐPd2ÐP2
N2ÐPd2ÐP2
C201ÐPd2ÐI2
N2ÐPd2ÐI2
108.64 (8)
120.28 (7)
112.94 (7)
81.95 (8)
93.81 (7)
175.10 (5)
170.30 (7)
89.52 (5)
C331ÐP3ÐPd3
C341ÐP3ÐPd3
C351ÐP3ÐPd3
C401ÐPd4ÐN4
C401ÐPd4ÐP4
N4ÐPd4ÐP4
Data collection: SMART (Bruker, 1998); cell re®nement: SAINT
(Bruker, 1998); data reduction: SAINT; program(s) used to solve
structure: SHELXS97 (Sheldrick, 1997); program(s) used to re®ne
structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP
(Siemens, 1994); software used to prepare material for publication:
SHELXL97.
95.77 (6)
168.13 (5)
167.88 (7)
87.77 (5)
92.847 (16)
108.49 (8)
122.76 (7)
113.26 (7)
C401ÐPd4ÐI4
N4ÐPd4ÐI4
P2ÐPd2ÐI2
94.495 (17) P4ÐPd4ÐI4
C231ÐP2ÐPd2
C241ÐP2ÐPd2
C251ÐP2ÐPd2
114.28 (8)
115.85 (8)
112.67 (8)
C431ÐP4ÐPd4
C441ÐP4ÐPd4
C451ÐP4ÐPd4
The authors thank Professor J. Vicente, University of
Murcia, for his continuing support and encouragement.
I1ÐPd1ÐP1ÐC131
I1ÐPd1ÐP1ÐC141
I1ÐPd1ÐP1ÐC151
Pd1ÐP1ÐC131ÐC132
Pd1ÐP1ÐC141ÐC142
Pd1ÐP1ÐC151ÐC152
87.82 (8) I3ÐPd3ÐP3ÐC331
155.74 (9) I3ÐPd3ÐP3ÐC341
29.24 (9) I3ÐPd3ÐP3ÐC351
174.63 (19) Pd3ÐP3ÐC331ÐC332
111.48 (19) Pd3ÐP3ÐC341ÐC342
110.40 (18) Pd3ÐP3ÐC351ÐC352
148.06 (8)
29.18 (9)
88.14 (9)
125.79 (19)
108.0 (2)
179.46 (19)
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: GD3068). Services for accessing these data are
described at the back of the journal.
C102ÐC101ÐC103ÐO101 17.2 (3)
C101ÐC102ÐC104ÐO102 95.5 (3)
I2ÐPd2ÐP2ÐC231
C302ÐC301ÐC303ÐO301 13.1 (4)
C301ÐC302ÐC304ÐO302 94.4 (3)
References
165.59 (9) I4ÐPd4ÐP4ÐC431
80.69 (8)
162.79 (9)
38.86 (8)
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(Version 2.0). Bruker AXS Inc., Madison, Wisconsin, USA.
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I2ÐPd2ÐP2ÐC251
Pd2ÐP2ÐC231ÐC232
Pd2ÐP2ÐC241ÐC242
Pd2ÐP2ÐC251ÐC252
43.87 (9) I4ÐPd4ÐP4ÐC441
74.91 (9) I4ÐPd4ÐP4ÐC451
128.6 (2)
93.2 (2)
Pd4ÐP4ÐC431ÐC432
174.12 (17)
129.76 (17)
113.42 (18)
C402ÐC401ÐC403ÐO401 9.4 (4)
Pd4ÐP4ÐC441ÐC442
169.81 (19) Pd4ÐP4ÐC451ÐC452
C202ÐC201ÐC203ÐO201 17.3 (4)
C201ÐC202ÐC204ÐO202 97.0 (3)
C401ÐC402ÐC404ÐO402 90.4 (3)
È
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Â
Because of the large number of parameters, full-matrix re®nement
was not possible, and the re®nement was therefore split into two
blocks consisting of molecules 1 and 2, and molecules 3 and 4,
respectively. Methyl H atoms were identi®ed in difference syntheses,
idealized, and re®ned as rigid groups allowed to rotate but not tip.
Other H atoms were included using a riding model. CÐH bond
(1999). Chem. Eur. J. 5, 3066±3075.
Â
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Segura, L. (2005). Organometallics, 24, 5044±5057.
Â
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2127±2138.
2
Ê
lengths were ®xed at 0.98 (methyl C) or 0.95 A (Csp ), and methyl
Â
Â
Vicente, J., Arcas, A., Galvez-Lopez, M. D. & Jones, P. G. (2006). Organo-
HÐCÐH angles were ®xed at 109.5ꢀ. Uiso(H) values were ®xed at 1.2
metallics, 25, 4247±4259.
ꢂ
Â
m18 Jones and Lopez-Serrano
[Pd(C19H17NO4)I(C18H15P)]
Acta Cryst. (2007). C63, m16±m18