Functionalized palladium(II) cyclometallated complexes. Crystal and molecular structures of [Pd{3-(CHO)C6H3C(H)=NCy}(μ- O2CMe)]2 and [Pd{3-(CHO)C6H3C(H)=NCy}(Cl)(PR3)] (PR3 = PEtPh2, and PEt2Ph)

Article abstract of DOI:10.1016/S0277-5387(02)01323-2

The crystal structure of the cyclometallated acetato-bridged complex [Pd{3-(CHO)C₆H₃C(H)=NCy}(μ- O₂CMe)]₂, 1 is reported. Each palladium atom is C, N-bonded to the chelating Schiff base ligand. The molecular configuration corresponds to the anti isomer, with the cyclopalladated moieties in an 'open-book' disposition. Treatment of 1 with aqueous sodium chloride gave the chloro-bridged compound 2, which when treated with tertiary phosphines yielded complexes 3 and 4. The crystal structures of complexes [Pd{3-(CHO)C₆H₃C(H)=NCy}(Cl)(PR₃)] (PR₃ = PEtPh₂, 3 and PEt₂Ph, 4) are also reported. In both complexes the palladium atom is bonded in a slightly distorted square-planar coordination to a carbon and a nitrogen atom of the Schiff base, a chlorine atom and to the phosphorus atom of the phosphine ligand. The reaction of the chloro-bridged complex 2 with the tertiary diphosphines Ph₂PCH₂PPh₂ (dppm) and Ph₂P(CH₂)₂PPh₂ (dppe) in a 1:2 molar ratio, and ammonium hexafluorophosphate, yielded the mononuclear cyclometallated complexes [Pd{3-(CHO)C₆H₃C(H)=NCy}{ Ph₂PCH₂PPh₂-P,P}][PF₆], 5 and [Pd{3- (CHO)C₆H₃C(H)=N-Cy}{Ph₂ P(CH₂)₂PPh₂-P,P}][PF₆], 6, respectively.

Full text of DOI:10.1016/S0277-5387(02)01323-2

Polyhedron 22 (2003) 241Á246
/
www.elsevier.com/locate/poly
Functionalized palladium(II) cyclometallated complexes. Crystal and
molecular structures of [Pd{3-(CHO)C6H3C(H)ÄNCy}(m-O2CMe)]2
and [Pd{3-(CHO)C6H3C(H)ÄNCy}(Cl)(PR3)] (PR3ꢀPEtPh2, and
PEt2Ph)
/
/
/
Jose´ M. Vila a,ꢁ, Gemma Alberdi a, Ma Teresa Pereira a, Marta Marino a,
˜
Alberto Ferna´ndez b, Margarita Lo´pez-Torres b, Raquel Ares b
a Departamento de Qu´ımica Inorga´nica, Universidad de Santiago de Compostela, Av. de las Ciencias s/n, E-15782 Santiago de Compostela, Spain
b Departamento de Qu´ımica Fundamental, Universidad de La Coruna, E-15071 La Coruna, Spain
˜
˜
Received 7 May 2002; accepted 21 October 2002
Abstract
The crystal structure of the cyclometallated acetato-bridged complex [Pd{3-(CHO)C6H3C(H)Ä
/
NCy}(m-O2CMe)]2, 1 is reported.
Each palladium atom is C, N-bonded to the chelating Schiff base ligand. The molecular configuration corresponds to the anti
isomer, with the cyclopalladated moieties in an ‘open-book’ disposition. Treatment of 1 with aqueous sodium chloride gave the
chloro-bridged compound 2, which when treated with tertiary phosphines yielded complexes 3 and 4. The crystal structures of
complexes [Pd{3-(CHO)C6H3C(H)Ä
/
NCy}(Cl)( PR3)] (PR3ꢀPEtPh2, 3 and PEt2Ph, 4) are also reported. In both complexes the
/
palladium atom is bonded in a slightly distorted square-planar coordination to a carbon and a nitrogen atom of the Schiff base, a
chlorine atom and to the phosphorus atom of the phosphine ligand. The reaction of the chloro-bridged complex 2 with the tertiary
diphosphines Ph2PCH2PPh2 (dppm) and Ph2P(CH2)2PPh2 (dppe) in a 1:2 molar ratio, and ammonium hexafluorophosphate,
yielded the mononuclear cyclometallated complexes [Pd{3-(CHO)C6H3C(H)Ä
(CHO)C6H3C(H)ÄNÃCy}{Ph2P(CH2)2PPh2-P,P}][PF6], 6, respectively.
# 2002 Elsevier Science Ltd. All rights reserved.
/NCy}{Ph2PCH2PPh2-P,P}][PF6], 5 and [Pd{3-
/
/
Keywords: Palladium(II) cyclometallated complexes; Crystal and molecular structures; Ammonium hexafluorophosphate; Chelating; Phosphines
1. Introduction
Although bidentate nitrogen-donor ligands may un-
dergo double metallation to give compounds with two
Cyclometallated compounds [1Á
an organic ligand links to a metal center through a sMÃ
C bond and additional bonding of the metal via an
appropriate donor atom completes the stable, more
often than not five-membered, metallated ring. Their
applications are widespread throughout the chemical
family, ranging from organic and organometallic chem-
/
5] are formed when
sMÃ
atom to different metal centers [12Á
conditions may influence the metallation process, thus
altering the number of MÃN, as well as MÃC, bonds in
/
C bonds and with coordination of each nitrogen
/
16], the reaction
/
/
/
the final compound. We have reported that bidentate
Schiff bases derived from dialdehydes, such as 1,4-
(CyNÄ
/
CH)2C6H4 and 1,3-(CyNÄ/CH)2C6H4, react
with palladium(II) acetate in glacial acetic acid to give
only monocyclometallated complexes after cleavage of
istry [6Á
processes [11].
/
9], to bioactive species [10] and catalytic
one CÄ
/
N double bond [17,18] and we have also been
interested in the study of the reactivity of these
complexes towards nucleophiles such as tertiary mono-
and diphosphines [19]. In either case, the parent chloro-
bridged dinuclear compound, such as 2, undergoes
scission of the Pd2Cl2 unit to render mononuclear
ꢁ Corresponding author. Tel.: ꢂ
81-595012
E-mail address: qideport@usc.es (J.M. Vila).
/
34-9-81-563100x14255; fax: ꢂ34-9-
/
0277-5387/02/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved.
PII: S 0 2 7 7 - 5 3 8 7 ( 0 2 ) 0 1 3 2 3 - 2

242
J.M. Vila et al. / Polyhedron 22 (2003) 241Á246
/
species. In the former case, compounds with terminal
PdÃCl bonds and with the palladium atom bonded to
2.1.2. [Pd{3-(CHO)C6H3C(H)Ä
/
/
NCy}{Ph2P(CH2)2PPh2-P,P}][PF6] 6
Yield 77%. Anal. Found: C, 54.9; H, 4.5; N, 1.4. Calc.
for C40H40F6NOP3Pd: C, 55.1; H, 4.7, N, 1.6%. IR:
four different atoms are produced, whereas in the latter,
the chlorine ligands are lost completely and 1:1 electro-
lyte species are formed with the diphosphine acting as a
chelating ligand. In spite that functionalized palladiu-
m(II) compounds, i.e. those bearing a non-coordinated
formyl unit, researched by us have been fully character-
ized [18], X-ray crystal diffraction data have been
somewhat limited and in the present paper we report
the crystal and molecular structures of three functiona-
lized palladium(II) cyclometallated complexes.
n(CÄ
(CDCl3, d ppm, J Hz): 9.83 [s, 1H, HCÄ
1H, HCÄN, J(PHi)ꢀ
1.8], 6.85 [m, 1H, H5, J(H4H5)ꢀ
/
O) 1694m, n(CÄ
/
N) 1618w cmꢃ1
.
1H NMR
O], 8.46 [d,
/
/
/
8.6], 7.92[d, 1H, H2, J(H2H4)ꢀ
/
/
8.0]. 31PÃ
26.3], 45.9d, ꢃ
/
{1H} NMR
(CDCl3, d ppm) 61.8 [d, J(PP)ꢀ
/
/146.1
[m, PF6ꢃ].
2.1.3. X-ray crystallographic study
For compound 1 three dimensional, room tempera-
ture (r.t.) X-ray data were collected on a Siemens P4
diffractometer in the range 3.68B
/
u B458 by the v scan
/
2. Experimental
method. The 9528 reflections measured were corrected
for Lorentz and polarization effects (but not for
absorption). The structure was solved by direct methods
and refined by full-matrix least-squares on F2 with
allowance for thermal anisotropy of all non-hydrogen
atoms. Hydrogen atoms were placed in calculated
positions and refined in riding mode. Refinement
2.1. General procedures
The synthesis of complexes 1Á4 has been reported
/
previously [18,19]. Solvents were purified by standard
methods [20]. Chemicals were reagent grade. The
phosphines Ph2PCH2PPh2 (dppm) and Ph2P(CH2)2PPh2
(dppe) were purchased from Aldrich-Chemie. Micro-
analyses were carried out using a Carlo Erba Elemental
Analyzer, Model 1108. IR spectra were recorded as
converged at a final Rꢀ
/
0.0961 (observed data, F) and
0.3244 (F2, 8286 unique data, 757 parameters).
wR2ꢀ
/
The structure solution and refinement were carried out
using the program package SHELX-97 [21].
Crystals of complexes 3 and 4 were mounted on a
glass fiber and transferred to a Bruker SMART CCD
single-crystal X-ray dffractometer. Three-dimensional,
r.t. X-ray data were collected by the v scan method
using graphite-monochromated Mo Ka radiation. All
the 14 146 (3) and 12 553 (4) measured reflections were
corrected for Lorentz and polarization effects and for
absorption by semi-empirical methods based on sym-
metry-equivalent and repeated reflections (transmissions
max./min. 0.947/0.757 and 0.963/0.638 for complexes 3
and 4, respectively). The structures were solved by direct
methods and refined by full-matrix least-squares on F2.
Hydrogen atoms were included in calculated positions
and refined in riding mode. Refinement converged at a
Nujol mulls or KBr discs on a PerkinÁElmer 1330 and
/
on a Mattson spectrophotometers. NMR spectra were
obtained as CDCl3 solutions and referenced to SiMe4
(1H, 13CÃ
/
{1H}) or 85% H3PO4 (31PÃ
/
{1H}) and were
recorded on Bruker WM-250, AMX-300 and AMX-500
spectrometers. All chemical shifts were reported down-
field from standards.
2.1.1. [Pd{3-(CHO)C6H3C(H)Ä
NCy}{Ph2PCH2PPh2-P,P}][PF6] 5
/
To a suspension of 2 (50 mg, 0.070 mmol) in acetone
(ca. 15 cm3), Ph2PCH2PPh2 (54 mg, 0.140 mmol) was
added and the resulting solution stirred for 2 h, after
which ammonium hexafluorophosphate was added and
the resulting suspension stirred for another 2 h; water
(ca. 15 cm3) was then added and the resulting mixture
stirred for a further 2 h, the orange precipitate formed
was filtered off, dried in vacuo and recrystallized from
final Rꢀ/0.0313 and 0.0419 (for complexes 3 and 4,
respectively, observed data, F) and wR2ꢀ
/
0.0808 and
0.928 (for complexes 3 and 4, respectively; F2, 6417 and
4995 unique data, 298 and 264 parameters), with
allowance for thermal anisotropy of all non-hydrogen
atoms. The structure solution and refinement were
carried out using the program package SHELX-97 [21].
dichloromethaneÁ
55.6; H, 5.0; N, 1.6. Calc. for C39H38F6NOP3Pd: C,
55.1; H, 4.5; N, 1.6%. IR: n(CÄO) 1693m, n(CÄN)
1617w cmꢃ1. H NMR (CDCl3, d ppm, J Hz): 9.85 [s,
1H, HCÄO], 8.35 [d, 1H, HCÄN, J(PHi)ꢀ8.4], 7.90[d,
1H, H2, J(H2H4)ꢀ1.8], 6.89 [m, 1H, H5, J(H4H5)ꢀ
8.3,
J(PH5ꢀ
5.4], 4.32 [dd, 2H, PCH2P, J(PH)ꢀ10.7, 11.2].
31PÃ{1H} NMR (CDCl3, d ppm) ꢃ
6.0 [d, J(PP)ꢀ
66.5], ꢃ29.4d, ꢃ
145.9 [h, PF6ꢃ].
Complex 6 was prepared similarly as a white solid.
/
hexane. Yield 58%. Anal. Found: C,
/
/
1
3. Results and discussion
/
/
/
/
/
In previous papers we described the preparation of
/
/
complexes 1Á4 [18,19], however, these have been
/
/
/
/
included to complete the reaction sequence which is
shown in Scheme 1. Compounds 5 and 6 were char-
acterized by elemental analysis (C, H, N) and by IR, 1H
/
/

J.M. Vila et al. / Polyhedron 22 (2003) 241Á
/246
243
Scheme 1. (i) NaCl (acetoneÁwater); (ii) PR3 (acetone 1:2 molar ratio; (iii) dppm or dppe (acetone 1:2 molar ratio).
/
and 31PÃ
2).
/
{1H} NMR spectroscopy (data in the Section
Table 1
Crystallographic data for complexes 1, 3 and 4
1
3
4
3.1. Crystal structure of [Pd{3-(CHO)C6H3C(H)Ä
/
Chemical
formula
Formula
weight
C
32H38N2O6Pd2 C28H31ClNOPPd C24H31ClNOPPd
NCy}(m-O2CMe)]2, 1
759.45
570.36
522.32
Crystals were grown by slowly evaporating
a
dichloromethaneÁn-hexane solution of the complex.
/
T (8C)
293(2)
0.71073
triclinic
293(2)
0.71073
monoclinic
293(2)
0.71073
monoclinic
˚
l (A)
The molecular structure is illustrated in Fig. 1. Crystal
data are given in Table 1 and selected bond distances
and angles with e.s.d. are shown in Table 2.
The crystal of complex 1 consists of discrete molecules
separated by van der Waals distances. The asymmetric
unit contains two molecules of 1 having similar struc-
tures, of which only one will be discussed here.
Each molecule may be described as a dimer with the
anti conformation and the cyclometallated fragments in
the characteristic open-book disposition, linked by two
Crystal
system
¯
Space group
˚
P/
1
/
P21/n
P21/c
a (A)
˚
13.410(5)
15.901(6)
16.242(8)
93.61(4)
90.67(3)
109.71(2)
3252(3)
4
8.599(17)
12.200(3)
24.810(3)
11.692(3)
13.876(4)
15.096(4)
b (A)
˚
c (A)
a (8)
b (8)
g (8)
V (A )
Z
m (mmꢃ1
94.89(2)
93.111(5)
3
˚
2593.4(9)
4
2445(11)
4
)
1.150
9528
0.901
14 146
0.948
12 553
Reflections
collected
Unique re-
flections
8291
6417
4995
(Rintꢀ0.114)
0.0961
0.3244
(Rintꢀ0.023)
0.0313
0.0808
(Rintꢀ0.045)
0.0419
0.0928
a
R1
wR2
b
a
R1ꢀSjjFojꢃjFcjj/SjFoj, [F ꢀ4s(F)].
b
wR2ꢀ[S[w(Fo2ꢃFc2)2/Sw(Fo2)2]1/2, all data.
acetate-bridging ligands. The palladium atoms are
bonded to the Schiff base ligand through a phenyl
carbon atom and the imine nitrogen atom and to two
oxygen atoms from the acetate-bridging ligands, in a
slightly distorted square-planar disposition.
The angles in the coordination sphere of palladium
are close to the expected value of 908, with the most
Fig. 1. Molecular structure of [Pd{3-(CHO)C6H3C(H)ÄNCy}(m-
/
O2CMe)]2, 1, with labeling scheme. Hydrogen atoms have been
omitted for clarity.
noticeable distortions corresponding to the C(1)Ã
/
Pd(1)Ã
/

244
J.M. Vila et al. / Polyhedron 22 (2003) 241Á246
/
Table 2
angles of the metallacycle are in accordance with
reported values [23,24]. The proximity of the Schiff
bases due to the dimeric nature of the complex leads to
inter-ligand repulsions on the open side of the molecule,
which results in the coordination planes of the palla-
dium atoms being tilted at an angle of 33.78.
In spite of these repulsions, the cyclometallated rings
(plane 1) are planar and almost coplanar with the
palladium coordination plane (plane 2) and with the
metallated phenyl rings (plane 3) [angles between planes
are as follow: plane 1/2, 2.78; plane 1/3, 2.28; plane 2/3,
4.48; planes to Pd(1)]. The high R values are probably
due to the quality of the crystal; we were unable to grow
a better specimen.
˚
Selected bond lengths (A) and angles (8) for complex 1
Bond lengths
Pd(1)ÃC(1)
Pd(1)ÃO(1)
Pd(1)ÃPd(2)
Pd(2)ÃN(2)
Pd(2)ÃO(3)
C(1)ÃC(6)
C(6)ÃC(7)
C(7)ÃN(1)
Pd(1A)ÃN(1A)
Pd(1A)ÃO(2A)
Pd(2A)ÃC(8A)
Pd(2A)ÃO(4A)
C(1A)ÃC(6A)
C(6A)ÃC(7A)
C(7A)ÃN(1A)
1.94(2)
Pd(1)ÃN(1)
2.020(12)
2.147(12)
1.95(2)
2.041(11) Pd(1)ÃO(2)
2.929(2) Pd(2)ÃC(8)
2.029(12) Pd(2)ÃO(4)
2.175(11) Pd(1A)ÃC(1A)
1.44(2)
1.43(2)
1.31(2)
2.061(11)
1.95(2)
1.41(2)
C(8)ÃC(13)
C(13)ÃC(14)
C(14)ÃN(2)
1.44(2)
1.30(2)
2.015(13) Pd(1A)ÃO(1A)
2.168(12) Pd(1A)ÃPd(2A)
2.034(11)
2.894(2)
2.025(13)
2.174(12)
1.43(2)
1.96(2)
Pd(2A)ÃN(2A)
2.051(12) Pd(2A)ÃO(3A)
1.39(2)
1.46(2)
1.24(2)
C(8A)ÃC(13A)
C(13A)ÃC(14A)
C(14A)ÃN(2A)
1.45(2)
1.27(2)
3.2. Crystal structures of [Pd{3-(CHO)C6H3C(H)Ä
/
Bond angles
NCy}(Cl)(PEtPh2)], 3 and [Pd{3-(CHO)C6H3C(H)Ä
/
C(1)ÃPd(1)ÃN(1)
N(1)ÃPd(1)ÃO(1)
N(1)ÃPd(1)ÃO(2)
C(8)ÃPd(2)ÃN(2)
N(2)ÃPd(2)ÃO(4)
N(2)ÃPd(2)ÃO(3)
C(6)ÃC(1)ÃPd(1)
C(7)ÃC(6)ÃC(1)
N(1)ÃC(7)ÃC(6)
C(7)ÃN(1)ÃPd(1)
C(1A)ÃPd(1A)ÃN(1A) 81.0(6) C(1A)ÃPd(1A)ÃO(1A)
N(1A)ÃPd(1A)ÃO(1A) 173.9(5) C(1A)ÃPd(1A)ÃO(2A) 175.2(6)
N(1A)ÃPd(1A)ÃO(2A) 97.1(5) O(1A)ÃPd(1A)ÃO(2A)
C(8A)ÃPd(2A)ÃN(2A) 81.6(6) C(8A)ÃPd(2A)ÃO(4A)
N(2A)ÃPd(2A)ÃO(4A) 173.8(5) C(8A)ÃPd(2A)ÃO(3A) 178.2(6)
N(2A)ÃPd(2A)ÃO(3A) 98.6(5) O(4A)ÃPd(2A)ÃO(3A) 87.1(5)
82.8(6) C(1)ÃPd(1)ÃO(1)
174.2(5) C(1)ÃPd(1)ÃO(2)
95.5(5) O(1)ÃPd(1)ÃO(2)
81.7(6) C(8)ÃPd(2)ÃO(4)
169.9(5) C(8)ÃPd(2)ÃO(3)
97.0(5) O(4)ÃPd(2)ÃO(3)
112.6(11) C(13)ÃC(8)ÃPd(2)
114.1(14) C(8)ÃC(13)ÃC(14)
117.0(2) N(2)ÃC(14)ÃC(13)
113.3(11) C(14)ÃN(2)ÃPd(2)
92.6(6)
176.0(6)
88.9(5)
NCy}(Cl)(PEt2Ph)], 4
Suitable crystals were grown by slowly evaporating
chloroform solutions of the complexes. The molecular
structures are illustrated in Figs. 2 and 3. Crystal data
are given in Table 1 and selected bond distances and
angles with e.s.d. are shown in Table 3.
The crystals of complexes 3 and 4 consist of discrete
molecules separated by van der Waals distances. The
geometry around the palladium atom may be regarded
as slightly distorted square-planar, with the Pd(II)
bonded to the C(1) carbon and the N(1) nitrogen atoms
of the Schiff base ligand, to the Cl(1) chlorine and to the
P(1) phosphorus atom of the tertiary monophosphine
93.1(6)
178.7(5)
88.3(5)
114.4(12)
113.0(2)
119.0(2)
112.6(10)
94.8(6)
86.8(5)
92.6(6)
C(6A)ÃC(1A)ÃPd(1A) 112.9(12) C(13A)ÃC(8A)ÃPd(2A) 112.5(11)
C(7A)ÃC(6A)ÃC(1A) 114.3(14) C(8A)ÃC(13A)ÃC(14A) 113.7(14)
N(1A)ÃC(7A)ÃC(6A) 115.8(14) N(2A)ÃC(14A)ÃC(13A) 117.0(14)
C(7A)ÃN(1A)ÃPd(1A) 115.9(11) C(14A)ÃN(2A)ÃPd(2A) 114.8(11)
N(1) and C(8)Ã
81.7(6)8, respectively, consequent upon chelation. This
is also shown by the value of the C(2)ÃC(1)ÃPd(1) and
C(9)ÃC(8)ÃPd(2) bond angles of 130.7(14)8 and
128.5(12)8, respectively, considerably larger than the
theoretical 1208. The Pd(1)ÃPd(2) bond length of is
/
Pd(2)Ã
/
N(2) angles of 82.8(6)8 and
/
/
/
/
/
noticeably larger than the sum of the covalent radii for
two square-planar palladium(II) atoms [22], thus pre-
cluding any Pdꢀ ꢀ ꢀPd interaction.
The Pd(1)Ã
/
C(1) and Pd(2)Ã
/
C(8) bond distances are
somewhat shorter than the values predicted from their
covalent radii [22], but similar to values found earlier
[23,24]. However, the Pd(1)Ã
/
N(1) and Pd(2)Ã/N(2) bond
lengths are in agreement with the value based on the
sum of covalent radii for nitrogen and palladium [22]
and similar to values reported previously [23,24]. The
differing Pd(1)Ã
/
O(1) and Pd(1)Ã
/
O(2), and Pd(2)Ã
/
O(4)
and Pd(2)ÃO(3) bond distances reflect the higher trans
/
Fig.
NCy}(Cl)(PEtPh2)], 3, with labeling scheme. Hydrogen atoms have
2. Molecular
structure
of
[Pd{3-(CHO)C6H3C(H)Ä
/
influence of the aryl carbon as compared with the imine
nitrogen atom. The remaining bond distances and bond
been omitted for clarity.

J.M. Vila et al. / Polyhedron 22 (2003) 241Á
/246
245
The Pd(1)Ã
/
C(1) bond lengths are shorter than the
˚
expected value of 2.081 A based on the sum of the
covalent radii for carbon and palladium [22], but similar
to other values reported [19,25,26]. However, the Pd(1)Ã
/
N(1) bond distances are considerably longer than the
˚
expected value of 2.01 A [22]. These values show the
high trans influence of the phosphine ligand [cf. with the
PdÃ
P(1) bond distances are within the expected values
[19,26]. The Pd(1)ÃCl(1) distances are somewhat longer
/
N bond length values in compound 1]. The Pd(1)Ã
/
/
than the expected values based on the sum of the
covalent radii [22], due to the trans influence of the
N distances are
C(1) phenyl carbon atom. The CÄ
/
consistent with those found earlier in other cyclometal-
lated complexes [15].
The geometry around the palladium atom is planar
[Pd(1), C(1), N(1), P(1), Cl(1), plane 1; mean deviation
˚
from the plane: 0.096 (3), 0.024 A (4)] and almost
coplanar with the cyclometallated [Pd(1), C(1), C(2),
C(8), N1(1), plane 2; mean deviation from the plane:
˚
0.018 (3), 0.036 A (4)] and phenyl [C(1)Ã
/
C(6), plane 3;
˚
mean deviation from the plane: 0.038 (3), 0.011 A (4)]
rings [angles between planes; plane 1/2: 7.08 (3), 3.38 (4);
plane 1/3: 9.88 (3), 6.28 (4); plane 2/3: 2.98 (3), 4.78 (4)].
Fig.
NCy}(Cl)(PEt2Ph)], 4, with labeling scheme. Hydrogen atoms have
3. Molecular
structure
of
[Pd{3-(CHO)C6H3C(H)Ä
/
been omitted for clarity.
3.3. Cyclometallated complexes with diphosphine ligands
Table 3
˚
Selected bond lengths (A) and angles (8) for complexes 3 and 4
Reaction of the chloro-bridged complex 2 with the
tertiary diphosphines PPh2CH2PPh2 (dppm) and
PPh2(CH2)2PPh2 (dppe) in a 1:2 molar ratio, and
ammonium hexafluorophosphate, yielded the mono-
3
4
Bond lengths
Pd(1)ÃC(1)
Pd(1)ÃN(1)
Pd(1)ÃPd(1)
Pd(2)ÃCl(2)
C(1)ÃC(2)
C(2)ÃC(8)
N(1)ÃC(8)
2.010(2)
2.117(2)
2.2668(7)
2.3698(7)
1.410(3)
1.456(3)
1.273(3)
2.019(4)
2.115(3)
2.258(1)
2.359(1)
1.408(6)
1.457(6)
1.267(5)
nuclear
(CHO)C6H3C(H)Ä
and [Pd{3-(CHO)C6H3C(H)Ä
cyclometallated
NCy}{Ph2PCH2PPh2-P,P}][PF6], 5
NCy}{Ph2P(CH2)2PPh2-
complexes
[Pd{3-
/
/
P,P}][PF6], 6, which were fully characterized (see
Section 2). The IR spectra of the complexes showed
the band assigned to the free formyl group at approxi-
mately 1693 cmꢃ1 and the band corresponding to the
Bond angles
C(1)ÃPd(1)ÃN(1)
C(1)ÃPd(1)ÃP(1)
N(1)ÃPd(1)ÃP(1)
C(1)ÃPd(1)ÃCl(1)
N(1)ÃPd(1)ÃCl(1)
P(1)ÃPd(1)ÃCl(1)
C(2)ÃC(1)ÃPd(1)
C(1)ÃC(2)ÃC(8)
C(8)ÃN(1)ÃPd(1)
N(1)ÃC(8)ÃC(2)
81.15(8)
94.37(7)
81.3(2)
95.2(1)
n(CÄ
shifted toward lower wavenumbers, as compared with
the non-coordinated ligand, due to PdÃN coordination
[27,28]. The IR spectra also showed the absence of the
/
N) stretch at approximately 1618 cmꢃ1, the latter
175.05(5)
168.61(7)
92.95(6)
176.1(1)
174.1(1)
93.0(1)
/
91.82(3)
111.61(61)
116.5(2)
90.54(5)
110.9(3)
116.9(4)
112.3(3)
118.2(4)
1
n(PdÃ
/
Cl) bands. In the H NMR spectra the HCÄ
/N
resonance signal showed coupling to only one of the
phosphorus nuclei [J(PH) ca. 8.5 Hz], presumably that
trans to it. The 1H NMR spectra also showed the singlet
112.58(16)
118.0(2)
resonance corresponding to the HCÄ
mately d9.83. The 31PÃ{1H} spectra showed two doub-
lets [J(PP)ꢀ66.5 and 26.3 Hz for complexes 5 and 6,
respectively] for the two inequivalent phosphorus nuclei.
The assignment of the doublets was made in accordance
with the assumption that a ligand of greater trans
influence shifts the resonance of the phosphorus atoms
trans to it to lower frequency [29].
/
O proton approxi-
/
ligand. The sum of the angles about the palladium
atoms is approximately 3608 as expected for a square-
planar geometry. The donor atoms of the chelating
Schiff base, occupying mutually cis positions force a bite
angle of 81.15(8)8 and 81.3(2)8 for complexes 3 and 4,
respectively, somewhat smaller than the expected 908.
/

246
J.M. Vila et al. / Polyhedron 22 (2003) 241Á246
/
[11] A. Mansour, M. Portnoy, J. Chem. Soc., Perkin Trans. 1 (2001)
952.
4. Supplementary data
[12] B.J. O’Keefe, P.J. Steel, Organometallics 17 (1998) 3621.
[13] J. Vicente, J.A. Abad, B. Rink, F.S. Herna´ndez, M.C. Ramirez de
Arellano, Organometallics 16 (1997) 5269.
Full details of data collection and structure refine-
ment have been deposited with the Cambridge Crystal-
lographic Data Center, CCDC reference number 184330
(1), 184331 (3) and 184332 (4). Copies of this informa-
tion may be obtained free of charge from The Director,
CCDC, 12 Union Road, Cambridge, CB2 1EZ, UK
[14] R.M. Ceder, J. Sales, X. Solans, M. Font-Altaba, J. Chem. Soc.,
Dalton Trans. (1986) 1351.
[15] J.M. Vila, M. Gayoso, M.T. Pereira, M. Camino-Rodriguez, J.M.
Ortigueira, J. Organomet. Chem. 426 (1992) 267.
[16] J.M. Vila, M. Gayoso, M.T. Pereira, M. Camino-Rodriguez, J.M.
Ortigueira, J.J. Ferna´ndez, M. Lo´pez-Torres, J. Organomet.
Chem. 479 (1994) 37.
(fax: ꢂ44-1223-336033); e-mail: deposit@ccdc.cam.a-
/
c.uk or www: http://www.ccdc.cam.ac.uk).
[17] J.M. Vila, M. Gayoso, M.T. Pereira, M. Lo´pez, G. alonso, J.J.
Ferna´ndez, J. Organomet. Chem. 445 (1993) 287.
[18] J.M. Vila, M. Gayoso, M.T. Pereira, M. Lo´pez-Torres, J.J.
Ferna´ndez, A. Ferna´ndez, J.M. Ortigueira, J. Organomet.
Chem. 506 (1996) 165.
Acknowledgements
We thank the Ministerio de Educacio´n y Cultura
(Proyecto PB98-0638-C02-01/02), the Xunta de Galicia
(Proyecto PGIDT99PXI20907B) and the Universidad
[19] J.M. Vila, M.T. Pereira, J.M. Ortigueira, M. Lo´pez-Torres, A.
Castineiras, D. Lata, J.J. Ferna´ndez, A. Ferna´ndez, J. Organo-
˜
met. Chem. 556 (1998) 31.
[20] D.D. Perrin, W.L.F. Armarego, Purification of Laboratory
Chemicals, 4th ed, Butterworth-Heinemann, London, 1996.
[21] G.M. Sheldrick, SHELX-97, An integrated system for solving and
refining crystal structures from diffraction data, University of
Gottingen, Germany, 1997.
de la Coruna for financial support.
˜
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