Cyclometallated compounds of Pd(II): C=N to C=O conversion through acid hydrolysis. Crystal and molecular structures of [Pd{2,4-(CHO)2C6H3} (Cl)(PPh3)2] and [Pd[2,4-(CHO)2C6H3}(Cl) (PPh3)2]

Article abstract of DOI:10.1016/S0022-328X(02)01704-7

Treatment of the chloro-bridged complex [Pd{4-(CHO)C₆H₃C(H)=NCy}(Cl)]₂ (1) with tertiary monophosphines in a 1:4 molar ratio gave the non-cyclometallated monomer complexes [Pd{4-(CHO)C₆H₃C(H)=NCy}(Cl)(PR₃)₂] (PR₃: (2) PPh₃, (3) PEtPh₂, (4) PEt₂Ph, (5) PMePh₂). The crystal structure of 2 is described. Reaction of complexes 2-5 with a mixture of glacial acetic acid-water gave the monomeric complexes [Pd[2,4-(CHO)₂C₆H₃}(Cl)(PR₃)₂] (PR₃ (6), PPh₃ (7), PEtPh₂ (8), PEt₂Ph (9), PMePh₂) after cleavage of the C=N group. Complex 6 was characterized crystallographically. Treatment of 1 with the triphosphine bis(2-diphenylphosphinoethyl) phenylphosphine in 1:2 molar ratio gave the mononuclear complex [Pd{4-(CHO)C₆H₃C(H)=NCy} {Ph₂P(CH₂)₂PPh(CH₂)₂PPh₂-P,P,P}][Cl] (10) in which the phosphine is coordinated through the three phosphorus atoms. Treatment of 10 with a mixture of acetic acid-water also caused cleavage of the C=N bond giving the complex [Pd{2,4-(CHO)₂ C₆H₃}{Ph₂P(CH₂)₂PPh(CH₂)₂PPh₂-P,P,P}][Cl] (11).

Full text of DOI:10.1016/S0022-328X(02)01704-7

Journal of Organometallic Chemistry 659 (2002) 67Á72
/
www.elsevier.com/locate/jorganchem
Cyclometallated compounds of Pd(II): CÄ
through acid hydrolysis. Crystal and molecular structures of [Pd{4-
NCy}(Cl)(PPh3)2] and [Pd{2,4-
/
N to CÄ
/
O conversion
(CHO)C6H3C(H)Ä
/
(CHO)2C6H3}(Cl)(PPh3)2]
Jose´ M. Vila a,*, Ma Teresa Pereira a, Gemma Alberdi a, Marta Marino a, Jesu´s
˜
J. Ferna´ndez b, Margarita Lo´pez Torres b, Raquel Ares b
a Departamento de Qu´ımica Inorga´nica, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain
b Departamento de Qu´ımica Fundamental, Universidad de La Coruna, E-15071 La Coruna, Spain
˜
˜
Received 15 May 2002; accepted 27 June 2002
Abstract
Treatment of the chloro-bridged complex [Pd{4-(CHO)C6H3C(H)Ä
ratio gave the non-cyclometallated monomer complexes [Pd{4-(CHO)C6H3C(H)Ä
PEt2Ph, (5) PMePh2). The crystal structure of 2 is described. Reaction of complexes 2Á
gave the monomeric complexes [Pd{2,4-(CHO)2C6H3}(Cl)(PR3)2] (PR3 (6), PPh3 (7), PEtPh2 (8), PEt2Ph (9), PMePh2) after
cleavage of the CÄN group. Complex 6 was characterized crystallographically. Treatment of 1 with the triphosphine bis(2-
diphenylphosphinoethyl)phenylphosphine in 1:2 molar ratio gave the mononuclear complex [Pd{4-(CHO)C6H3C(H)Ä
NCy}{Ph2P(CH2)2PPh(CH2)2PPh2-P,P,P}][Cl] (10) in which the phosphine is coordinated through the three phosphorus atoms.
Treatment of 10 with a mixture of acetic acidÁwater also caused cleavage of the CÄN bond giving the complex [Pd{2,4-
/
NCy}(Cl)]2 (1) with tertiary monophosphines in a 1:4 molar
NCy}(Cl)(PR3)2] (PR3: (2) PPh3, (3) PEtPh2, (4)
5 with a mixture of glacial acetic acidÁwater
/
/
/
/
/
/
/
(CHO)2C6H3}{Ph2P(CH2)2PPh(CH2)2PPh2-P,P,P}][Cl] (11). # 2002 Elsevier Science B.V. All rights reserved.
Keywords: Cyclometallation; Palladium(II); Tertiary phosphines
1. Introduction
Cyclometallated compounds involve sMÃ
formation and additional coordination of the metal
atom to a suitable ligand donor atom. The donor atom,
as well as the metal and chelate ring size, serve as a basis
for their classification; by far the most well-studied
examples are the five-membered palladacycles contain-
ligand 1,4-(CyNÄ
/
CH)2C6H4 and 1,3-(CyNÄ
/
CH)2C6H4
in glacial acetic acid [9,10]. The acidic nature of the
/C bond
solvent caused selective cleavage of one of the CÄ
double bonds pertaining to the uncoordinated CÄ
group. The second CÄ
against hydrolysis due to intramolecular coordination to
the palladium atom. Bearing this in mind we reasoned
that opening of the cyclometallated ring should make
the imine group susceptible to hydrolysis. Thus, in the
present paper, we report the reaction of the chloro-
bridged cyclometallated complex 1 with tertiary mono-
phosphines to give non-cyclometallated species after
/N
/N
/N moiety seems to be protected
ing PdÃ
they show a wide range of applications in organic and
organometallic chemistry [6Á8].
/
N and C(phenyl)Ã
/
Pd bonds [1Á5]. Currently
/
/
Previously, we have prepared cyclometallated com-
plexes with an uncoordinated formyl group. The synth-
esis of such compounds was performed by reaction of
palladium(II) acetate and the appropriate Schiff base
PdÃ
and CÄ
compound is described. Subsequent treatment with a
mixture of acetic acidÁwater produced cleavage of the
/
N bond cleavage, supporting uncoordinated CÄ
/N
/
O groups. The crystal structure of one such
/
second imine group of the organic ligand yielding a
compound with two free formyl moieties: the equivalent
* Corresponding author. Fax: ꢀ
E-mail address: qideport@usc.es (J.M. Vila).
/
34-81-595-012
0022-328X/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 2 - 3 2 8 X ( 0 2 ) 0 1 7 0 4 - 7

68
J.M. Vila et al. / Journal of Organometallic Chemistry 659 (2002) 67Á72
/
of metallating the organic aldehyde. We also report, the
structure of one of these complexes, which to the best of
our knowledge is the first example of its kind to be
crystallographically characterized.
complexes 2Á5 with a mixture of glacial acetic acid and
/
water gave the mononuclear species [Pd{2,4-
(CHO)2C6H3}(Cl)(PR3)2] (PR3: (6) PPh3, (7) PEtPh2,
(8) PEt2Ph, (9) PMePh2), respectively, which were fully
characterized. The IR spectra showed the absence of the
n(CÄ
/
N) band and, in the case of complexes 6 and 7, two
bands corresponding to the free formyl groups (in the
spectra of 8 and 9 the bands overlapped). The IR spectra
2. Results and discussion
also showed the n(PdÃ
/
Cl) stretch precluding the sub-
stitution of the chloro ligand by an acetate ligand from
The compounds and reactions are shown in Scheme 1.
The compounds described in this paper were character-
ized by elemental analysis (C, H, N) and by IR, 1H- and
31P{1H}- spectroscopy (data in the Section 3).
The reaction of the chloro-bridged complex 1 [11]
with tertiary monophosphines in a 1:4 molar ratio gave
the non-cyclometallated monomer complexes [Pd{4-
acetic acid. Cleavage of the imine group was confirmed
by the absence of the HCÄ
spectra and by the presence of two singlet signals in the
range d 10.04Á9.62 corresponding to the HCÄO moi-
/
N resonance in the 1H-NMR
/
/
eties. The trans disposition of the phosphine ligands was
confirmed by the presence of one only singlet resonance
in the 31P{1H} spectra.
(CHO)C6H3C(H)Ä/NCy}(Cl)(PR3)2] (PR3: (2) PPh3, (3)
PEtPh2, (4) PEt2Ph, (5) PMePh2), which were fully
characterized (see Section 3). The IR spectra of the
complexes showed the band assigned to the free formyl
group ca. 1685 cmꢁ1, and the band corresponding to
Reaction of 1 with the triphosphine bis(2-diphenyl-
phosphinoethyl)phenylphosphine in 1:2 molar ratio
gave the mononuclear complex [Pd{4-(CHO)-
C6H3C(H) Ä
/
NCy}{Ph2P(CH2)2PPh(CH2)2PPh2-
the n(CÄ
cmꢁ1, respectively. The latter was consistent with a
trans-ClÃPdÃ
C geometry [12]. The 1H-NMR spectra
showed singlet resonances ca. d 9.75 and 8.20, assigned
to the HCÄO and HCÄN protons, respectively. Neither
the H6 nor the HCÄ
N protons showed coupling to the
31P-nucleus of the phosphine due to the opening of the
cyclometallated ring [10,13]. In the absence of PdÃ
bond, the metallated phenyl ring can rotate about the
/
N) and n(PdÃ/Cl) stretches ca. 1630 and 295
P,P,P}][Cl] (10), The phosphorus resonances in the
31P{1H}-NMR spectrum were downfield shifted from
their values in the free phosphine suggesting coordina-
tion of the three phosphorus atoms to the metal center.
A broad resonance at d 81.8 was assigned to the central
31P-nucleus, trans to the phenyl carbon atom, and the
signal at d 38.7 was assigned to the two equivalent
mutually trans phosphorus nuclei. The latter signal
appeared at lower frequency in accordance with the
higher trans influence of the phosphine ligand [12]. The
H6 resonance appeared as a triplet showing coupling
only to the central phosphorus atom [J(PH) 7.8 Hz] and
to H5. These data are in accordance with a disposition in
which the metallated ring is nearly perpendicular to the
plane defined by the three phosphorus atoms [14,15].
/
/
/
/
/
/
N
PdÃC vector so that its plane is at 908 to the palladium
/
coordination plane and coupling of the H6 proton to the
31P-nucleus is absent [10,13]. The 31P{1H}-NMR spectra
showed a singlet resonance confirming the trans geo-
metry of the phosphine ligands.
Whereas cyclometallation precludes cleavage of the
CÄ
/
N group bonded to palladium, as in compound 1,
The shift of the n(CÄ
wavenumbers (as compared with the non-coordinated
ligand) [16,17] as well as the upfield shift of the HCÄ
proton resonance in the 1H-NMR spectra [18] indicated
the existence of palladiumÁnitrogen interaction in solu-
/N) stretching vibration to lower
scission of the PdÃ
/N bond, upon reaction with phos-
phines, allows further hydrolysis of the second CÄN
double bond to give an additional non-coordinated
/
/N
formyl group on the metallated ring. Thus, reaction of
/
tion. These results strongly agree with those previously
obtained by us in related penta-coordinated palladiu-
m(II) species, and hence we propose a similar disposi-
tion of the triphos ligand in this case [14,15].
Nevertheless, the PdÃ
pound 10 is not sufficiently strong to hinder cleavage of
the CÄN group, as in 1, upon treatment with acetic acid
media. Therefore, reaction of 10 with a mixture of acetic
acidÁwater gave [Pd{2,4-(CHO)2C6H3}{Ph2P-
(CH2)2PPh(CH2)2PPh2-P,P,P}][Cl] (11), after cleavage
of the CÄN bond. The IR spectrum of 11 showed two
strong bands at 1689 and 1666 cmꢁ1 assigned to the two
/
N bond interaction in com-
/
/
/
formyl groups and the absence of the n(CÄ
/
N) stretch.
The 1H- and 31P{1H}-NMR spectra of the complex
showed similar characteristics to the one of 10, with the
Scheme 1. (i) PR3 (acetone 1:4 molar ratio); (ii) acetic acidÁ
triphos (acetone 1:2 molar ratio).
/water; (iii)

J.M. Vila et al. / Journal of Organometallic Chemistry 659 (2002) 67Á
/72
69
most noticeable differences corresponding to the ab-
sence of the HCÄN signal and to the appearance of two
HCÄO resonances.
/
/
2.1. Crystal structures of [Pd{4-(CHO)C6H3C(H)Ä
/
NCy}(Cl)(PPh3)2] (2) and [Pd{2,4-
(CHO)2C6H3}(Cl)(PPh3)2] (6)
Suitable crystals were grown by slowly evaporating
chloroformÁn-hexane solutions of the complexes. The
/
molecular structures are illustrated in Figs. 1 and 2.
Crystal data are given in Table 1 and selected bond
distances and angles with estimated standard deviations
are shown in Table 2.
The crystal structures consist of discrete molecules
separated by van der Waals distances. The asymmetric
unit of 6 comprises two molecules with similar struc-
tures, of which only one will be discussed, and two
chloroform solvent molecules.
Fig. 2. Molecular structure of [Pd{2,4-(CHO)2C6H3}(Cl)(PPh3)2] (6),
with labeling scheme. Hydrogen atoms have been omitted for clarity.
Table 1
Crystallographic data for complexes 2 and 6
In both compounds, the four coordinated palladium
atom is bonded to the phenyl carbon atom of the
metallated phenyl ring, one chloro ligand and to two
phosphorus atoms of the mutually trans-triphenylpho-
sphine ligands. The coordination sphere of the palla-
dium may be described as slightly distorted square-
planar. The angles between adjacent atoms in the
coordination sphere of palladium are close to the
2
6
Chemical formula
Formula weight
T (8C)
l (A)
Crystal system
Space group
C50H46ClNOPd2Pd
880.67
293(2)
C45H36Cl4O2P2Pd
918.88
293(2)
˚
0.71073
Orthorhombic
Pbca
0.71073
Monoclinic
P21/c
˚
a (A)
13.839(4)
23.239(8)
31.95(1)
21.341(1)
19.044(1)
21.911(1)
110.127(1)
8361.2(2)
8
˚
b (A)
expected value of 908, in the range 91.9(3)Á
and 88.5(2)Á91.24(6)8 for complexes 2 and 6, respec-
tively.
The Pd(1)Ã
/
88.3(1)8
˚
c (A)
/
b (8)
3
V (A )
˚
8791(5)
/C(1) bond distances [2.021(11), 2; and
Z
8
0.593
34 168
m (mmꢁ1
)
0.813
47 210
1.994(5), 6] are somewhat shorter than the values
predicted from the sum of their covalent radii [19], but
similar to values reported earlier suggesting some degree
Collected reflections
Unique reflections
6899 (Rintꢂ0.029)
0.0942
0.2951
14 701 (Rintꢂ0.061)
0.0559
0.1652
a
R1
of multiple bonding [20Á
bond distances are also within the expected values [20Á
23]. The geometry about the palladium atoms is planar
/
23]. The PdÃ
/
P and PdÃ
/
Cl
b
wR2
/
a
R1ꢂajjFojꢁjFcjj/ajFoj, [F ꢀ4s(F)].
wR2ꢂ[a[w(F2oꢁFc2)2/a w(Fo2)2]1/2, all data.
b
[mean deviations form the Pd(1), C(1), P(1), P(2), Cl(1)
˚
plane of 0.0211 and 0.0221 A, for complexes 2 and 6,
respectively]. The metallated ring forms an angle of ca.
908 with the palladium coordination plane (100.2 and
90.78 for 2 and 6, respectively), confirming the 1H-NMR
data (vide supra). In complex 6, the two formyl groups
and the metallated phenyl ring are nearly coplanar (see
Fig. 3), whereas in complex 2 the metallated ring and the
HCÄ
/
O group are also coplanar but the HCÄ/N moiety is
slightly out of the plane, probably due to the steric
interaction between the phosphine phenyl groups and
the cyclohexyl moiety.
No interaction was observed between the imine
nitrogen and the palladium atom in 2. Such contact
has been reported previously in other non cyclometal-
lated complexes of palladium(II) with phosphine ligands
Fig.
1. Molecular
structure
of
NCy}(Cl)(PPh3)2] (2), with labeling scheme. Hydrogen atoms have
[Pd{4-(CHO)C6H3C(H)Ä
/
been omitted for clarity.

70
J.M. Vila et al. / Journal of Organometallic Chemistry 659 (2002) 67Á72
/
Table 2
˚
Selected bond lengths (A) and angles (8) for complexes 2 and 6
2
6
Bond lengths
Pd(1)ÃC(1)
Pd(1)ÃCl(1)
Pd(1)ÃP(1)
Pd(1)ÃP(2)
C(2)ÃC(7)
C(7)ÃN(1)
2.02(1)
2.358(3)
2.333(4)
2.316(3)
1.42(2)
1.28(2)
Pd(1)ÃC(1)
Pd(1)ÃCl(1)
Pd(1)ÃP(1)
Pd(1)ÃP(2)
C(2)ÃC(7)
C(7)ÃO(1)
1.994(1)
2.387(2)
2.328(2)
2.342(2)
1.466(9)
1.208(8)
Pd(2)ÃC(51)
Pd(2)ÃCl(2)
Pd(2)ÃP(3)
Pd(2)ÃP(4)
C(52)ÃC(57)
C(57)ÃO(3)
1.992(6)
2.388(2)
2.333(2)
2.334(2)
1.468(8)
1.216(7)
Bond angles
C(1)ÃPd(1)ÃP(2)
C(1)ÃPd(1)ÃP(1)
P(2)ÃPd(1)ÃP(1)
C(1)ÃPd(1)ÃCl(1)
P(1)ÃPd(1)ÃCl(1)
P(2)ÃPd(1)ÃCl(1)
90.7(3)
91.9(3)
175.8(1)
176.4(3)
88.3(6)
88.9(1)
C(1)ÃPd(1)ÃP(2)
C(1)ÃPd(1)ÃP(1)
P(2)ÃPd(1)ÃP(1)
C(1)ÃPd(1)ÃCl(1)
P(1)ÃPd(1)ÃCl(1)
P(2)ÃPd(1)ÃCl(1)
89.4(2)
88.5(2)
C(51)ÃPd(2)ÃP(4)
C(51)ÃPd(2)ÃP(3)
P(4)ÃPd(2)ÃP(3)
C(51)ÃPd(2)ÃCl(2)
P(3)ÃPd(2)ÃCl(2)
P(4)ÃPd(2)ÃCl(2)
89.5(2)
88.8(2)
176.44(6)
178.7(2)
90.73(6)
91.24(6)
173.64(6)
178.2(2)
90.18(6)
91.27(6)
were carried out using a Carlo Erba Elemental Analy-
zer, Model 1108. IR spectra were recorded as Nujol
mulls or KBr discs on a PerkinÁElmer 1330 and on a
/
Mattson spectrophotometers. NMR spectra were ob-
tained as CDCl3 solutions and referenced to SiMe4 (1H,
13C{1H}) or 85% H3PO4 (31P{1H}) and were recorded
on Bruker WM-250, AMX-300 and AMX-500 spectro-
meters. All chemical shifts were reported downfield from
standards.
3.2. Preparation of [Pd{4-(CHO)C6H3C(H)Ä
/
NCy}(Cl)(PPh3)2] (2)
PPh3 (74.0 mg, 0.280 mmol) was added to a solution
of 1 (50.0 mg, 0.070 mmol) in acetone (15 cm3). The
mixture was stirred for 4 h at room temperature (r.t.)
and the resulting white precipitate was filtered off and
Fig. 3. Planar disposition of the metallated phenyl and the two formyl
groups.
recrystallized from dichloromethaneÁhexane. Yield
/
[20,24]. We believe this could be due to the steric
hindrance that pushes the cyclohexyl ring away from
the neighboring phosphine phenyl rings, thus restricting
approximation of the nitrogen lone pair to the palla-
dium atom.
89%. Anal. Found: C, 69.2; H, 5.9; N, 1.6.
C50H46NOPdP2Cl requires C, 68.7; H, 5.4; N, 1.6%.
IR: n(CÄ
Cl), 290m cmꢁ1. 1H-NMR (CDCl3, d ppm, J Hz): 9.76
[s, 1H, HCÄO], 8.26 [s, 1H, HCÄ
N], 7.69[d, 1H, H3,
J(H3H5)ꢂ
8.0], 6.62
/
O), 1685s cmꢁ1; n(CÄ
/
N), 1625s cmꢁ1; n(PdÃ
/
/
/
1.9], 6.98 [dd, 1H, H5, J(H5H6)ꢂ
/
In the molecular structure of 6 the C(2)Ã
/
C(H)Ä/O
/
[d, 1H, H6]. 31P{1H}-NMR (CDCl3, d ppm) 22.6s.
Compounds 3, 4 and 5 were prepared similarly as
yellow solids.
oxygen is directed toward the palladium atom, however,
˚
O(1) distance of 2.930 A precluded any
the Pd(1)Ã
/
interaction between both atoms.
3.3. [Pd{4-(CHO)C6H3C(H)Ä
/NCy}(Cl)(PEtPh2)2]
3. Experimental
(3)
3.1. General procedures
Yield: 73%. Anal. Found: C, 64.5; H, 5.4; N, 1.5.
C42H46NOPdP2Cl requires C, 64.3; H, 5.9; N, 1.8%. IR:
The synthesis of complexes 1, 2 and 5 has been
reported previously [8]. Solvents were purified by
standard methods [25]. Chemicals were reagent grade.
The phosphines PPh3, PEtPh2, PEt2Ph and PMePh2
were purchased from Aldrich-Chemie. Microanalyses
n(CÄ
293m cmꢁ1. H-NMR (CDCl3, d ppm, J Hz): 9.74 [s,
1H, HCÄO], 8.25 [s, 1H, HCÄ
N], 7.69 [d, 1H, H3,
J(H3H5)ꢂ1.9], 7.02 [dd, 1H, H5, J(H5H6)ꢂ
8.0], 6.73
[d, 1H, H6]. 31P{1H}-NMR (CDCl3, d ppm) 32.9s.
/
O), 1688s cmꢁ1; n(CÄ
/
N), 1635s cmꢁ1; n(PdÃ
/Cl),
1
/
/
/
/

J.M. Vila et al. / Journal of Organometallic Chemistry 659 (2002) 67Á
/72
71
3.4. [Pd{4-(CHO)C6H3C(H)Ä
/
NCy}(Cl)(PEt2Ph)2]
1685s s cmꢁ1; n(PdÃ
/
Cl), 292m cmꢁ1
.
1H-NMR
(4)
(CDCl3, d ppm, J Hz): 10.4, 9.78 [s, 2H, HCÄ
/
O].
31P{1H}-NMR (CDCl3, d ppm) 32.5s.
Yield: 45%. Anal. Found: C, 50.7; H, 5.9; N, 1.7.
C34H42NOPdP2Cl×2CH2Cl2 requires C, 50.4; H, 5.9; N,
1.6%. IR: n(CÄ
O), 1689s cmꢁ1; n(CÄN), 1632s cmꢁ1
n(PdÃ
Cl), 297m cmꢁ1 1H-NMR (CDCl3, d ppm, J
Hz): 9.77 [s, 1H, HCÄO], 8.18 [s, 1H, HCÄN], 7.70[d,
/
3.9. [Pd{2,4-(CHO)2C6H3}(Cl)(PMePh2)2] (9)
/
/
;
/
.
Yield: 88%. Anal. Found: C, 59.6; H, 5.0.
C34H31O2PdP2Cl requires C, 60.5; H, 4.7. IR: n(CÄO),
1683s s cmꢁ1; n(PdÃCl), 297m cmꢁ1 1H-NMR
(CDCl3, d ppm, J Hz): 10.0, 9.66 [s, 2H, HCÄO].
31P{1H}-NMR (CDCl3, d ppm) 29.0s.
/
/
/
1H, H3, J(H3H5)ꢂ
/
1.9], 7.13 [dd, 1H, H5, J(H5H6)ꢂ
/
/
.
8.1], 6.63 [d, 1H, H6]. 31P{1H}-NMR (CDCl3, d ppm)
32.4s.
/
Compound 10 was prepared as a yellow solid,
following a procedure similar to the one employed in
the synthesis of 2 but using a cyclometallated compound
3.5. [Pd{4-(CHO)C6H3C(H)Ä
/
NCy}(Cl)(PMePh2)2]
(5)
1Átriphosphine 1:2 molar ratio.
/
Yield: 70%. Anal. Found: C, 58.3; H, 5.7; N, 1.4.
C40H42NOPdP2Cl.CH2Cl2 requires C, 58.5; H, 5.3; N,
3.10. [Pd{4-(CHO)C6H3C(H)Ä
/
NCy}{Ph2P(CH2)2-
1.7%. IR: n(CÄ
n(PdÃ
Cl), 293m cmꢁ1
Hz): 9.70 [s, 1H, HCÄO], 8.42 [s, 1H, HCꢂ
/
O), 1687s cmꢁ1; n(CÄ
/
N), 1635s cmꢁ1
;
PPh(CH2)2PPh2-P,P,P}][Cl] (10)
/
.
1H-NMR (CDCl3, d ppm, J
N], 7.05 [dd,
/
/
Yield: 95%. Anal. Found: C, 62.0; H, 5.8; N, 1.8.
1H, H5, J(H5H6)ꢂ
/
8.0, J(H5H3)ꢂ
/
1.6], 6.94 [d, 1H, H6];
C48H49ClNOP3Pd×
N, 1.5%. IR: n(CÄ
NMR (CDCl3, d ppm, J Hz): 9.77 [s, 1H, HCÄ
[s, 1H, HCÄ 7.3], 6.07 [t,
N], 6.81 [d, 1H, H5, J(H5H6)ꢂ
1H, H6, J(H6P)ꢂ7.3]. 31P{1H}-NMR (CDCl3, d ppm)
81.8br, 38.7br.
/0.5CH2Cl2 requires C, 62.4; H, 5.4;
the H3 signal was occluded by the phosphine phenyl
resonances. 31P{1H}-NMR (CDCl3, d ppm) 28.9s.
/
O) 1689s, n(CÄ
/
N) 1625m cmꢁ1. H-
1
/O], 8.19
/
/
3.6. Preparation of [Pd{2,4-
(CHO)2C6H3}(Cl)(PPh3)2] (6)
/
Compound 11 was synthesized following a similar
procedure to that for 6 but using a cyclometallated
H2O (2 cm3) was added to a solution of 2 (50.0 mg,
0.056 mmol) in glacial acetic acid (15 cm3). The mixture
was stirred for 48 h at r.t. The acetic acid was then
removed under vacuum, water added to the residue and
the product extracted with dichloromethane. The com-
bined extracts were dried over anhydrous sodium
sulfate, filtered and the solvent removed under vacuum
to give a pale yellow solid which was recrystallized from
complex 1Átriphosphine 1:2 molar ratio.
/
3.11. [Pd{2,4-(CHO)2C6H3}{Ph2P(CH2)2-
PPh(CH2)2PPh2-P,P,P}][Cl] (11)
Yield: 63%. Anal. Found: C, 62.1; H, 5.0.
C42H38ClO2P3Pd requires C, 62.3; H, 4.7. IR: n(CÄ
/
O)
1689s, 1666s cmꢁ1. H-NMR (CDCl3, d ppm, J Hz):
9.83, 9.66 [s, 2H, HCÄ
O], 7.91 [s, 1H, H3], 6.96 [d, 1H,
1
dichloromethaneÁ
66.3; H, 4.9. C44H35O2PdP2Cl requires C, 66.1; H, 4.4.
IR: n(CÄ
O), 1732w, 1681s cmꢁ1; n(PdÃCl), 296s cmꢁ1
1H-NMR (CDCl3, d ppm, J Hz): 9.86, 9.63 [s, 2H, HCÄ
O], 7.05 [dd, 1H, H5, J(H5H6)ꢂ7.9, J(H3H5)ꢂ
1.9],
7.08[d, 1H, H6]. 31P{1H}-NMR (CDCl3, d ppm) 22.0s.
Compounds 7Á9 were synthesized following a similar
/hexane. Yield: 70%. Anal. Found: C,
/
/
/
.
H5, J(H5H6)ꢂ
/
7.0], 6.54 [t, 1H, H6, J(H6P)ꢂ
7.0].
/
/
31P{1H}-NMR (CDCl3, d ppm) 93.7br, 44.5br.
/
/
3.12. X-ray crystallographic data
/
procedure as orange (7 and 9) and yellow (8) solids.
3.7. [Pd{2,4-(CHO)2C6H3}(Cl)(PEtPh2)2] (7)
Yield: 67%. Anal. Found: C, 60.9; H, 4.6.
Three-dimensional, r.t. X-ray data were collected on a
Bruker Smart CCD diffractometer by the v-scan
method using graphite-monochromated MoÁKa radia-
/
tion. All the measured reflections were corrected for
Lorentz and polarization effects and for absorption by
semi-empirical methods based on symmetry-equivalent
and repeated reflections. 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
C36H35O2PdP2Cl requires C, 61.5; H, 5.0. IR: n(CÄ
1691s, 1710sh, m cmꢁ1; n(PdÃCl), 285s cmꢁ1 1H-
O].
/O),
/
.
NMR (CDCl3, d ppm, J Hz): 9.96, 9.62 [s, 2H, HCÄ
/
31P{1H}-NMR (CDCl3, d ppm) 34.7s.
3.8. [Pd{2,4-(CHO)2C6H3}(Cl)(PEt2Ph)2] (8)
converged at a final Rꢂ
plexes 2 and 6, respectively, observed data, F) and
wR2ꢂ0.2951 and 0.1652 (for complexes 2 and 6,
respectively, unique data, F2), with allowance for
/
0.0942 and 0.0559 (for com-
Yield: 45%. Anal. Found: C, 56.1; H, 5.5.
C28H35O2PdP2Cl requires C, 61.5; H, 5.0. IR: n(CÄO),
/
/

72
J.M. Vila et al. / Journal of Organometallic Chemistry 659 (2002) 67Á72
/
[9] 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.
thermal anisotropy of all non-hydrogen atoms. The
structure solution and refinement were carried out using
the program package SHELX-97 [26].
[10] 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.
[11] We have previously reported the synthesis of compounds 1, 2 and
5. Compound 1 is brought here as the starting material for the
remaining complexes, and compounds 2 and 5 are included to
complete the reaction scheme, which leads to the new species 6
and 9, respectively. Furthermore, the crystal structure of 2, which
was unknown, is now reported.
4. Supplementary data
Full details of data collection and structure refine-
ment have been deposited with the Cambridge Crystal-
lographic Data Centre, CCDC reference number 184328
(2) and 184329 (6). Copies of this information may be
obtained free of charge from the Director, CCDC, 12
[12] B. Crociani, T. Boshi, R. Pietropaolo, U. Belluco, J. Chem. Soc.
A (1970) 531.
[13] J.M. Vila, M. Gayoso, M.T. Pereira, A. Romar, J.J. Ferna´ndez,
M. Thornton-Pett, J. Organomet. Chem. 401 (1991) 385.
[14] J.M. Vila, M.T. Pereira, J.M. Ortigueira, J.J. Ferna´ndez, A.
Ferna´ndez, M. Lo´pez-Torres, H. Adams, Organometallics 18
(1999) 5484.
Union Road, Cambridge, CB2 1EZ, UK (Fax: ꢀ44-
1223-336033; e-mail: deposit @ccdc.cam.ac.uk or www:
http://www.ccdc.cam.ac.uk).
/
[15] M. Lo´pez-Torres, A. Ferna´ndez, J.J. Ferna´ndez, A. Sua´rez, M.T.
Pereira, J.M. Ortigueira, J.M. Vila, H. Adams, Inorg. Chem. 40
(2001) 4583.
Acknowledgements
[16] H. Onoue, I. Moritani, J. Organomet. Chem. 43 (1972)
431.
We thank the Ministerio de Educacio´n y Cultura
(Proyecto PB98-0638-C02-01/02), the Xunta de Galicia
(Proyecto PGIDT99PXI20907B) and the Universidad
[17] H. Onoue, K. Minami, K. Nakagawa, Bull. Chem. Soc. Jpn. 43
(1970) 3480.
de la Coruna for financial support.
˜
[18] Y. Ustynyuk, V.A. Chertov, J.V. Barinov, J. Organomet. Chem.
29 (1971) C53.
[19] L. Pauling, The Nature of the Chemical Bond, third ed., Cornell
University Press, New York, 1960.
References
[20] J. Granell, J. Sales, J. Vilarrasa, J.P. Declercq, G. Germain, C.
Miravitlles, X. Solans, J. Chem. Soc. Dalton Trans. (1983) 2441.
[21] J. Dehand, J. Fischer, M. Pfeffer, A. Mitschler, M. Zinsius, Inorg.
Chem. 15 (1976) 1976.
[1] I. Omae, Organometallic Intramolecular-Coordination Com-
pounds, Elsevier Science, Amsterdam, New York, 1986.
[2] V.V. Dunina, O.A. Zalevskaya, V.M. Potapov, Russ. Chem. Rev.
571 (1984) 250.
[22] J. Vicente, J.A. Abad, B. Rink, F.S. Herna´ndez, M.C. Ram´ırez de
Arellano, Organometallics 16 (1997) 5269.
[3] G.R. Newkome, W.E. Puckett, W.K. Gupta, G.E. Kiefer, Chem.
Rev. 86 (1986) 451.
[23] J. Vicente, J.A. Abad, E. Mart´ınez-Viviente, M.C. Ram´ırez de
Arellano, Organometallics 19 (2000) 752.
[4] A.D. Ryabov, Chem. Rev. 90 (1990) 403.
[5] M. Pfeffer, Recl. Trav. Chim. Pays-Bas 109 (1990) 567.
[6] M. Pfeffer, J.P. Sutter, M.A. Rottevel, A. de Cian, J. Fischer,
Tetrahedron 48 (1992) 2427.
[24] J. Granell, R. Moraga´s, J. Sales, M. Font-Bard´ıa, X. Sola´ns, J.
Organomet.Chem. 431 (1992) 359.
[25] D.D. Perrin, W.L.F. Armarego, Purification of Laboratory
Chemicals, fourth ed., Butterwort-Heinemann, London, 1996.
[26] G.M. Sheldrick, SHELX-97, An Integrated System for Solving and
Refining Crystal Structures from Diffraction Data, University of
[7] A.D. Ryabov, R. van Eldik, G. Le Borgne, M. Pfeffer,
Organometallics 12 (1993) 1386.
[8] J. Dupont, M. Pfeffer, J. Spencer, Eur. J. Inorg. Chem. (2001)
1917.
Gottingen, Germany, 1997.
¨