Cyclopalladated compounds with a bidentate [C, N]/terdentate [C, N, S]benzylidenethiophene imine ligand

Article abstract of DOI:10.1016/S0022-328X(02)01401-8

Reaction of the Schiff base ligand 2,3-(MeO)₂C₆H₃C(H)=NCH₂ (C₄H₃S) (1), with palladium(II) acetate in toluene gave the dinuclear cyclometallated complex [Pd{2,3-(MeO)₂C₆H₂C(H)=NCH₂ (C₄H₃S)}(μ-OAc)]₂ (2), with the ligand bonded to the palladium atom through the imine nitrogen and the C6 carbon atom. The X-ray crystal structure of complex 2 is described. The reaction of 2 with aqueous sodium chloride gave the chloro-bridged complex [Pd{2,3-(MeO)₂C₆H₂C(H)=NCH₂ (C₄H₃S)} (μ-Cl)]₂ (3), after a metathesis reaction. Reaction of 3 with PPh₃ in acetone gave the mononuclear cyclometallated complex [Pd{2,3-(MeO)₂C₆H₂C(H)=NCH₂ (C₄H₃S)}(Cl)(PPh₃)] (4), in a bridge-splitting reaction. Treatment of 4 with silver triflate gave the cyclometallated complex [Pd{2,3-(MeO)₂C₆H₂C(H)=NCH₂ (C_4H3S)}(PPh₃)][CF₃SO₃] (7), with the palladium atom bonded to four different atoms C, N, S and P. Reaction of 3 with the diphosphines dppp and dppb in a 1:1 molar ratio gave the dinuclear cyclometallated complexes [{Pd[2,3-(MeO)₂C₆H₂C(H)=NCH₂ (C₄H₃S)](Cl)}₂(μ-Ph₂ P(CH₂)_nPPh₂)] (5: n = 3; 6: n = 4), with the diphosphine bridging the two palladium atoms. The X-ray crystal structures of complexes 4 and 6 are reported.

Full text of DOI:10.1016/S0022-328X(02)01401-8

Journal of Organometallic Chemistry 654 (2002) 162Á169
/
www.elsevier.com/locate/jorganchem
Cyclopalladated compounds with a bidentate [C, N]/terdentate
[C, N, S] benzylidenethiophene imine ligand. Crystal and molecular
structures of [Pd{2,3-(MeO)2C6H2C(H)Ä
/
NCH2(C4H3S)}(m-OAc)]2,
[Pd{2,3-(MeO)2C6H2C(H)ÄNCH2(C4H3S)}Ã
/
/
(Cl)×(PPh3)] and
/
[{Pd[2,3-(MeO)2C6H2C(H)ÄNCH2(C4H3S)](Cl)}2(m-
/
Ph2P(CH2)4PPh2)]
Alberto Ferna´ndez a,*, Digna Va´zquez-Garc´ıa a, Jesus J. Ferna´ndez a, Margarita Lo´pez-
´
Torres a, Antonio Sua´rez a, Roberto Mosteiro a, Jose´ M. Vila b,*
a Departamento de Qu´ımica Fundamental, Universidad de La Coruna, E-15071 La Coruna, Spain
˜
˜
b Departamento de Qu´ımica Inorga´nica, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain
Received 11 February 2002; accepted 5 March 2002
Abstract
Reaction of the Schiff base ligand 2,3-(MeO)2C6H3C(H)Ä
dinuclear cyclometallated complex [Pd{2,3-(MeO)2C6H2C(H)Ä
palladium atom through the imine nitrogen and the C6 carbon atom. The X-ray crystal structure of complex 2 is described. The
reaction of 2 with aqueous sodium chloride gave the chloro-bridged complex [Pd{2,3-(MeO)2C6H2C(H)ÄNCH2(C4H3S)}(m-Cl)]2
(3), after a metathesis reaction. Reaction of 3 with PPh3 in acetone gave the mononuclear cyclometallated complex [Pd{2,3-
(MeO)2C6H2C(H)ÄNCH2(C4H3S)}(Cl)(PPh3)] (4), in a bridge-splitting reaction. Treatment of 4 with silver triflate gave the
cyclometallated complex [Pd{2,3-(MeO)2C6H2C(H)ÄNCH2(C4H3S)}(PPh3)][CF3SO3] (7), with the palladium atom bonded to four
different atoms C, N, S and P. Reaction of 3 with the diphosphines dppp and dppb in a 1:1 molar ratio gave the dinuclear
3; 6: nꢀ4), with the
/NCH2(C4H3S) (1), with palladium(II) acetate in toluene gave the
/
NCH2(C4H3S)}(m-OAc)]2 (2), with the ligand bonded to the
/
/
/
cyclometallated complexes [{Pd[2,3-(MeO)2C6H2C(H)Ä
/
NCH2(C4H3S)](Cl)}2(m-Ph2P(CH2)nPPh2)] (5: nꢀ
/
/
diphosphine bridging the two palladium atoms. The X-ray crystal structures of complexes 4 and 6 are reported. # 2002 Elsevier
Science B.V. All rights reserved.
Keywords: CÃH activation; Cyclometallation; Phosphorus ligands; Schiff bases; Palladium
/
1. Introduction
Cyclometallated compounds [1Á
bond formation and additional coordination of the
metal atom to a suitable ligand donor atom. Currently
they show a wide range of applications in organic and
organometallic chemistry [6]. We have studied the
synthesis and reactivity of cyclometallated complexes
derived from ligands bearing more than one donor
atom, i.e. [C, N, O] [7,8] and [C, N, N] [9Á12] terdentate
/
/
5] involve sM Ã
/C
ligands; more recently we have dealt with potentially [C,
N, S] terdentate ligands and we have shown that
reaction of palladium(II) and platinum(II) salts with
thiosemicarbazones yields cyclometallated complexes
with an unusual tetranuclear structure (Scheme 1, I)
[13,14]. However, treatment of the related Schiff base
ligands with palladium(II) acetate gave complexes with a
mononuclear structure (Scheme 1, II) [15].
* Corresponding authors. Tel.: ꢁ
/
34-981-563100x14255; fax: ꢁ34-
/
In both cases, the ligand was coordinated through the
carbon, nitrogen and sulfur atoms. In the present paper
we report the chemistry of the Schiff base 2,3-
981-167065 (J.M.V.); fax: ꢁ34-981-167065 (A.F.).
/
E-mail addresses: qiluaafl@udc.es (A. Ferna´ndez), qideport@usc.es
(J.M. Vila).
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 4 0 1 - 8

A. Ferna´ndez et al. / Journal of Organometallic Chemistry 654 (2002) 162Á
/169
163
atoms in the 13C{1H} spectrum confirmed metallation
[9,15]. The FAB mass spectrum of 2 showed a cluster of
peaks, centered at 852 amu which corresponded to
[M]ꢁ. The isotopic pattern is in good agreement with
the expected dinuclear structure.
Treatment of 2 with aqueous sodium chloride gave
Scheme 1.
the chloro-bridged complex [Pd{2,3-(MeO)2C6H2C(H)Ä
/
NCH2(C4H3S)}(m-Cl)]2 (3), which was fully character-
ized (see Section 3). The IR spectrum showed the
absence of the n(COO) bands. A singlet resonance in
(MeO)2C6H3C(H)Ä
/
NCH2(C4H3S) (1), a potentially bi-
dentate [C, N]/terdentate [C, N, S] ligand. The reaction
of 1 with palladium(II) acetate yielded the dinuclear
cyclometallated complex showing the characteristic
folded structure with acetato-bridging ligands, 2, in
which 1 is only [C, N] bonded and the sulfur atom is not
prone to bind directly to the palladium atom in contrast
to other sulfur-bearing ligands; however, this may be
achieved by creating a vacant coordination site by
treatment of the corresponding complex with a Ag(I)
salt, as is shown for the chloro-bridged derivative. We
also report the reactivity of the chloro-bridged complex
3 with tertiary mono- and diphosphines and the crystal
structures of two of these compounds are described.
the 1H-NMR spectra at d 8.08 was assigned to the HCÄ
/
N proton. The signals corresponding to the H4 and H5
protons appeared as doublets at d 6.98 and 6.70. The
FAB mass spectra showed a peak at 765 amu assigned
to the [Mꢂ
Cl]ꢁ fragment.
/
2.2. Molecular structure of [Pd{2,3-
(MeO)2C6H2C(H)ÄNCH2(C4H3S)}(m-OAc)]2 (2)
/
Suitable crystals were grown by slowly evaporating a
chloroform/n-hexane solution of the complex. The
molecular structure is illustrated in Fig. 1. Crystal data
are given in Table 1 and selected bond distances and
angles with estimated standard deviations are shown in
Table 2.
2. Results and discussion
2.1. Preparation of the cyclometallated complexes
The structure consists of dimeric molecules separated
by van der Waals distances. In each monomeric unit the
palladium atom is bonded to a phenyl carbon atom, the
imine nitrogen of the Schiff base ligand and to two
The compounds and reactions are shown in Scheme 2.
The compounds described in this paper were character-
ized by elemental analysis (C, H, N) and by IR
spectroscopy and by 1H, 31P{1H} and, in part,
13C{1H}-NMR spectroscopy and FAB mass spectro-
metry (data in Section 3).
oxygen atoms of the acetato bridging ligands. The
˚
Pd(2) distance of 2.877(1) A, similar to values
Pd(1)Ã
/
found earlier [20], precluded any interaction between the
metal atoms. The geometry about the palladium atom
can be regarded as slightly distorted square-planar. The
sum of angles at the palladium atoms is approximately
3608. The angles between adjacent atoms in the co-
ordination sphere are close to the expected value of 908;
Reaction of the Schiff base ligand 2,3-
(MeO)2C6H3C(H)Ä
m(II) acetate in toluene gave the dinuclear cyclometal-
lated complex
[Pd{2,3-(MeO)2C6H2C(H)Ä
NCH2(C4H3S)}(m-OAc)]2 (2), which was fully charac-
N)
/NCH2(C4H3S) (1), with palladiu-
/
the most noticeable distortion corresponds to the C(1)Ã
Pd(1)ÃN(1) and C(19)ÃPd(2)ÃN(2) angles of 81.5(1)
and 81.3(1)8, respectively, consequent upon chelation.
The Pd(1)ÃC(1) and Pd(2)ÃC(19) bond distances of
/
terized. The IR spectrum of 2 showed the n(CÄ
/
stretch at 1609 cmꢂ1, shifted to lower wavenumbers (as
compared to the free ligand) due to N-coordination of
the imine [16,17]. The IR spectrum also showed strong
bands assigned to the symmetric and asymmetric
n(COO) vibrations, in agreement with those expected
for bridging acetate ligands [18] (see Section 3). The 1H-
NMR spectrum showed the resonance corresponding to
/
/
/
/
/
˚
1.967(3) and 1.964(3) A, respectively, are somewhat
shorter than the values predicted from their covalent
radii [21] but similar to values found earlier [20,22].
However, the Pd(1)Ã
/
N(1) and Pd(2)Ã
/
N(2) bond lengths
˚
of 2.023(2) and 2.014(2) A, respectively, are in agree-
ment with the value based on the sum of covalent radii
for nitrogen and palladium [21] and similar to values
the HCÄ/N proton at d 7.55, shifted to lower frequency,
confirming coordination of the ligand through the lone
pair of the nitrogen atom [19]. The absence of the signal
due to the H6 proton showed that metallation had
occurred at the C6 carbon. The signals assigned to the
diastereotopic CH2 protons, consequent on the folded
arrangement of the acetato-bridged dimmers, appeared
reported previously [20,22]. The differing Pd(1)Ã
/
O(3)
O(5) [2.051(2) and 2.132(2) A, respectively]
O(6) and Pd(2)ÃO(4) [2.029(2) and 2.146(2)
˚
and Pd(1)Ã
/
and Pd(2)Ã
/
/
˚
A, respectively] bond distances reflect the higher trans
influence of the aryl carbon as compared to the imine
nitrogen atom.
at d 4.10 and 4.71 [J(HH)
of the signals assigned to the C1, C6 and CHÄ
ꢀ
/
16.6 Hz]. The low-field shift
N carbon
/

164
A. Ferna´ndez et al. / Journal of Organometallic Chemistry 654 (2002) 162Á169
/
Scheme 2. (i) Pd(AcO)2 (toluene); (ii) NaCl (acetone/water); (iii) PPh3 (acetone); (iv) dppp or dppb (acetone, 1:1 molar ratio); (v) (1) AgCF3SO3; (2)
PPh3 (acetone); (vi) AgCF3SO3 (acetone)
2.3. Reactivity of the cyclometallated complexes
doublets, respectively, showing coupling to the 31P
nucleus [d 8.43 (JPH
ꢀ
/
8.4) and d 5.96 (JPH
ꢀ5.9 Hz),
/
respectively]. The 31P{1H} spectrum showed the phos-
phorus resonance at d 42.9. These findings and the low-
Reaction of the chloro-bridged compound 3 with
triphenylphosphine yielded the mononuclear complex
frequency shift of the C4Ã
shielding by a phosphine phenyl ring) were in agreement
with a phosphorus trans to nitrogen arrangement [23Á
26]. The FAB mass spectrum showed peaks centered at
665 and 628 amu assignable to the [M]ꢁ and [MꢂCl]ꢁ
fragments.
/
OMe resonance (due to
[Pd{2,3-(MeO)2C6H2C(H)Ä
(4), which was fully characterized (see Section 3). The IR
spectrum showed the low-wavenumbers shift of the
/
NCH2(C4H3S)}(Cl)(PPh3)]
/
n(CÄ
[16,17]. The HCÄ
1H-NMR spectrum as a doublet an a doublet of
/
N) stretch due to N-coordination of the ligand
/
N and H5 resonances appeared in the
/
Treatment of 4 with silver triflate and triphenylpho-
sphine in acetone gave the mononuclear complex
[Pd{2,3-(MeO)2C6H2C(H)Ä
/
NCH2(C4H3S)}(PPh3)][CF3SO3], (7), after AgCl re-
moval with the palladium atom bonded to four different
atoms: C, N, P and S. The most noteworthy difference
in the 1H-NMR spectrum of 7 as compared to 4, was the
CH2 proton resonance which appeared at d 5.23 (5.42 in
4). Unfortunately, the H10 signal was occluded by the
phosphine phenyl protons in both cases. The 13C{1H}
NMR spectra showed the high-frequency shift (2.4 ppm)
of the CH2 signal which appeared at d 57.5. The
conductivity measurements carried out in dry acetoni-
trile have shown the complex to be a 1:1 electrolyte.
Complex 7 could also be prepared by reaction of
complex 3 with silver triflate and subsequent treatment
with triphenylphosphine.
Fig.
1. Molecular
structure
of
[Pd{2,3-(MeO)2C6H2C(H)Ä
/
Reaction of 3 with the tertiary diphosphines
Ph2P(CH2)3PPh2 (dppp) and Ph2P(CH2)4PPh2 (dppb)
NCH2(C4H3S)}(m-OAc)]2 (2), with labelling scheme. Hydrogen atoms
have been omitted for clarity.

A. Ferna´ndez et al. / Journal of Organometallic Chemistry 654 (2002) 162Á
/169
165
Table 1
Crystallographic data for complexes 2, 4 and 6
Table 2
˚
Selected bond lengths (A) and angles (8) for complex 2
2
4
6
Bond lengths
Pd(1)ÃC(1)
Pd(1)ÃN(1)
Pd(1)ÃO(3)
Pd(1)ÃO(5)
1.967(3)
2.023(2)
2.051(2)
2.132(2)
Pd(2)ÃC(19)
Pd(2)ÃN(2)
Pd(2)ÃO(4)
Pd(2)ÃO(6)
1.964(3)
Chemical for-
mula
Formula weight 851.53
C32H34N2O8
Pd2S2
C32H29ClNO2
PPdS
664.44
C58H60Cl6N2O4
P2Pd2S2
1400.64
2.014(2)
2.146(2)
2.029(2)
T (8C)
293(2)
0.71073
Crystal system Monoclinic
293(2)
0.71073
Triclinic
293(2)
0.71073
Bond angles
˚
l (A)
C(1)ÃPd(1)ÃN(1)
C(1)ÃPd(1)ÃO(3)
N(1)ÃPd(1)ÃO(3)
C(1)ÃPd(1)ÃO(5)
N(1)ÃPd(1)ÃO(5)
O(3)ÃPd(1)ÃO(5)
81.5(1)
91.4(1)
C(19)ÃPd(2)ÃN(2)
C(19)ÃPd(2)ÃO(6)
81.4(1)
92.2(1)
Triclinic
¯
¯
P1/
Space group
˚
P21/n
/
/
P1/
172.92(9) N(2)ÃPd(2)ÃO(6)
177.7(1)
C(19)ÃPd(2)ÃO(4)
96.41(9) N(2)ÃPd(2)ÃO(4)
90.67(9) O(6)ÃPd(2)ÃO(4)
172.99(9)
175.2(1)
94.24(9)
91.02(9)
a (A)
˚
13.184(1)
14.259(1)
18.139(1)
8.798(2)
15.871(4)
21.401(6)
89.970(4)
89.888(5)
78.526(4)
2928.4(13)
4
10.668(1)
12.124(1)
13.123(1)
74.865(2)
74.475(2)
70.299(2)
1512.3(3)
1
b (A)
˚
c (A)
a (8)
b (8)
g (8)
V (A )
Z
m (mmꢂ1
99.371(1)
3
˚
3364.8(3)
4
1.245
In both compounds the four coordinated Pd atom is
bonded to the phenyl carbon atom and the imine
nitrogen of the Schiff base ligand, one chloro ligand
and to the phosphorus atom of the phosphine ligand.
The coordination sphere of the palladium may be
described as slightly distorted square-planar. The angles
between adjacent atoms in the coordination sphere of
palladium are close to the expected value of 908 with the
most noticeable distortions corresponding to the bite
)
0.881
18 321
1.028
10 335
Reflections col- 22 847
lected
Reflections Un- 8285
13 071
7276
ique
R1
[Rintꢀ0.031]
0.0320
0.0836
[Rintꢀ0.015]
0.0296
0.0714
[Rintꢀ0.054]
0.0588
0.1305
a
b
wR2
a
R1ꢀa jjFojꢂjFcjj/a jFoj, [F ꢀ4s(F)].
wR2 ꢀa [w(F 2o ꢂF o2 )2=a w(F 2o)2]1=2; all data.
b
/
angles C(1)Ã
81.08(9) and 81.20(9)8, respectively for complex 4 and
C(1)ÃPd(1)ÃN(1) of 81.2(2)8 for compound 6. The sum
of the angles about palladium is approximately 3608.
/
Pd(1)Ã
/
N(1) and C(33)Ã
/
Pd(2)Ã
/
N(2) of
/
/
in a 1:1 molar ratio gave the dinuclear cyclometallated
complexes [{Pd[2,3-(MeO)2C6H2C(H)ÄNCH2(C4H3S)]-
(Cl)}2(m-Ph2P(CH2)nPPh2)] (5; nꢀ3; 6: nꢀ4) which
were fully characterized (see Section 3). The symmetric
nature of the complexes was established by the presence
of only one singlet signal in the 31P{1H} spectra ca. d
34.
˚
/
The PdÃ
/
C [2.033(2) and 2.034(2) A for complex 4 and
˚
/
/
2.025(5) A for complex 6] and PdÃ
/
N bond distances
˚
˚
[2.098(2) A for complex 4 and 2.115(4) A for complex 6]
are similar to values reported earlier [8,24]. The PdÃ
bond length shows the high trans influence of the
phosphine phosphorus as compared to oxygen [PdÃ
/N
/N
2.4. Molecular structure of [Pd{2,3-
(MeO)2C6H2C(H)Ä
/
NCH2(C4H3S)}(Cl)(PPh3)] (4)
and [{Pd[2,3-(MeO)2C6H2C(H)Ä
/
NCH2(C4H3S)](Cl)}2(m-Ph2P(CH2)4PPh2)] (6)
Suitable crystals were grown by slowly evaporating
dichloromethane/n-hexane 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 estimated standard deviations
are shown in Table 3.
The crystal of complex 4 consists of discrete molecules
separated by van der Waals distances (two molecules per
asymmetric unit).
The crystal structure of 6 comprises a centrosym-
dinuclear
metric
molecule
of
[{Pd[2,3-
(MeO)2C6H2C(H)Ä
/
NCH2(C4H3S)](Cl)}2(m-
Fig.
NCH2(C4H3S)}(Cl)(PPh3)] (4), with labelling scheme. Hydrogen atoms
2. Molecular
structure
of
[Pd{2,3-(MeO)2C6H2C(H)Ä
/
Ph2P(CH2)4PPh2)] (half of the molecule per asymmetric
unit) and a dichloromethane solvent molecule.
have been omitted for clarity.

166
A. Ferna´ndez et al. / Journal of Organometallic Chemistry 654 (2002) 162Á169
/
on a Bruker AC-200F spectrometer. All chemical shifts
were reported downfield from standards. The FAB mass
spectra were recorded using a Quatro mass spectrometer
with a Cs ion gun; 3-nitrobenzyl alcohol was used as the
matrix. Conductivity measurements were made on a
CRISON GLP 32 conductivimeter using 10ꢂ3
M
solutions in dry acetonitrile.
3.1.1. Preparation of 2,3-(MeO)2C6H3C(H)Ä
/
NCH2(C4H3S) (1)
2,3-Dimethoxybenzaldehyde (2.00 g, 12.05 mmol) was
added to a solution of 2-thiophenemethylamine (1.36 g,
12.02 mmol) in 50 cm3 of dry CHCl3. The solution was
Fig. 3. Molecular structure of [{Pd[2,3-(MeO)2C6H2C(H)Ä
NCH2(C4H3S)](Cl)}2(m-Ph2P(CH2)4PPh2)] (6), with labelling scheme.
Hydrogen atoms have been omitted for clarity.
/
heated under reflux in a DeanÁStark apparatus for 4 h.
/
After cooling to room temperature (r.t.) the CHCl3 was
removed to give a yellow oil. Yield: 2.84 g, 90%. Anal.
Found: C, 64.3; H, 5.7; N, 5.5. Calc. for C14H15SO2N:
˚
distances 2.023(2) and 2.014(2) A for complex 2]. The
Cl bond distances are also within the
expected values [24].
C, 64.3; H, 5.8; N, 5.4%. IR: n(CÄ
NMR (200 MHz, CDCl3, d ppm, J Hz): 8.79 [s, 1H, Hi],
7.65 [dd, 1H, H6, J(H6H5)ꢀ7.8, J(H6H4)ꢀ
1.7], 7.25
2.7], 7.10 (t,
/
N), 1637 s cmꢂ1. 1H-
PdÃ
/
P and PdÃ
/
/
/
No intra or intermolecular interactions were observed
for the thiophene sulfur.
[dd, 1H, H9, J(H9H10)ꢀ
/
3.6, J(H9H8)ꢀ
/
1H, H5), 6.98 (m, 3H, H4, H8, H10), 5.01 (s, 2H, CH2),
3.90 (s, 3H, MeO), 3.88 (s, 3H, MeO). 13C{1H}-NMR
(50.28 MHz, CDCl3, d ppm): 158.3 (CÄ
/
N); 152.7, 149.5,
3. Experimental
142.3, 129.6 (C1, C2, C3, C7); 126.8, 124.8, 124.6, 124.2
(C4, C8, C9, C10); 119.0 (C6); 114.6 (C5) 59.7 (CH2);
61.8, 55.8 (MeO).
3.1. General procedures
Solvents were purified by standard methods [27].
Chemicals were reagent grade. The phosphines PPh3,
Ph2P(CH2)3PPh2 (dppp) and Ph2P(CH2)4PPh2 (dppb)
were purchased from Aldrich-Chemie. Microanalyses
were carried out using a Carlo Erba Elemental Analy-
zer, Model 1108. IR spectra were recorded as Nujol
3.1.2. Preparation of [Pd{2,3-(MeO)2C6H2C(H)Ä
/
NCH2(C4H3S)}(m-OAc)]2 (2)
A pressure tube containing 2,3-(MeOC6H3)2C(H)Ä
NCH2(C4H3S) (1), (142 mg, 0.54 mmol), palladium(II)
acetate (120 mg, 0.54 mmol) and 20 cm3 of dry
C6H5CH3 was sealed under Ar. The resulting mixture
was heated at 60 8C for 12 h. After cooling to r.t. the
solution was filtered through celite to remove the black
palladium formed. The solvent was removed under
vacuum to give a brown oil, which was chromato-
/
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
Table 3
˚
Selected bond lengths (A) and angles (8) for complexes 4 and 6
4
6
Bond lengths
Pd(1)ÃC(1)
Pd(1)ÃN(1)
Pd(1)ÃP(1)
Pd(1)ÃCl(1)
2.033(2)
2.098(2)
2.2430(7)
2.3640(8)
Pd(2)ÃC(33)
Pd(2)ÃN(2)
Pd(2)ÃP(2)
Pd(2)ÃCl(2)
2.034(2)
2.098(2)
2.2446(7)
2.3656(8)
Pd(1)ÃC(1)
Pd(1)ÃN(1)
Pd(1)ÃP(1)
Pd(1)ÃCl(1)
2.025(5)
2.115(4)
2.263(1)
2.387(1)
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)
81.20(9)
92.51(7)
173.69(6)
170.78(7)
92.22(6)
93.97(3)
C(33)ÃPd(2)ÃN(2)
C(33)ÃPd(2)ÃP(2)
N(2)ÃPd(2)ÃP(2)
C(33)ÃPd(2)ÃCl(2)
N(2)ÃPd(2)ÃCl(2)
P(2)ÃPd(2)ÃCl(2)
81.08(9)
92.65(7)
173.70(6)
170.80(7)
92.29(6)
98.89(3)
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)
81.2(2)
92.2(1)
173.0(1)
171.0(1)
92.3(1)
91.16(5)

A. Ferna´ndez et al. / Journal of Organometallic Chemistry 654 (2002) 162Á
/169
167
graphed on a column packed with silica gel. Elution
with CH2Cl2ÁEtOH (1.2%) afforded the final product
127.6d, J(PC)ꢀ
FAB-MS: m/zꢀ
H)Pd]ꢁ.
Compounds 5Á
procedure as yellows solids but using a complex 3Á
diphosphine 2:1 molar ratio.
/
10.6 Hz; Cp 130.6d, J(PC)ꢀ
/
2.84 Hz.
/
/
665 [M]ꢁ; 628 [Mꢂ
/
Cl]ꢁ; 366 [(Lꢂ
/
after concentration, as a yellow crystalline solid. Yield:
0.11 g, 25%. Anal. Found: C, 45.2; H, 4.1; N, 3.4. Calc.
for C32H34N2O8Pd2S2: C, 45.1; H, 4.0; N, 3.3%. IR:
/
6 were obtained following a similar
/
n(CÄ
/
N), 1609 s cmꢂ1; nas(COO), 1583 m cmꢂ1
;
ns(COO), 1416 s cmꢂ1. H-NMR (200 MHz, CDCl3,
1
d ppm, J Hz): 7.55 [t, 1H, Hi, J(H1CH2)ꢀ
6.75 (m, H4, H5, H8, H10), 6.96 [dd, 1H, H9, J(H9H10)Ä
4.9, J(H9H8)ꢀ
3.4], 4.10 [dd, 2H, CH2, J(CHH)ꢀ16.6],
4.71 (dd, 2H, CH2), 3.82 (s, 3H, MeO), 3.75 (s, 3H,
MeO), 2.17 (s, 3H, OAc). 13C{1H} NMR (50.28 MHz,
/
1.5], 7.27,
3.1.5. [{Pd[2,3-(MeO)2C6H2C(H)Ä
/
/
NCH2(C4H3S)](Cl)}2(m-Ph2P(CH2)3PPh2)] (5)
Yield: 0.07 g, 58%. Anal. Found: C, 54.7; H, 4.5; N,
2.5. Calc. for C55H54Cl2N2O4P2Pd2S2: C, 54.3; H, 4.5;
/
/
N, 2.3%. IR: n(CÄ
MHz, CDCl3, d ppm, J Hz): 8.36 [d, 1H, Hi J(HiP)ꢀ
7.3], 7.18 [d, 1H, H8, J(H8H9)ꢀ2.4], 7.01 [dd, 1H, H9,
J(H9H10)ꢀ4.9], 6.20 [d, 1H, H4, J(H4H5)ꢀ
8.3], 5.96
/
N), 1617 s cmꢂ1 1H-NMR (200
.
CDCl3, d ppm): 181.2 (OC(CH3)O); 168.6 (CÄ
/N);
/
149.2, 147.8, 144.5 (C2, C3, C7); 138.7, 136.2 (C1, C6);
115.1 (C4); 128.7 (C5); 127.3, 126.7, 126.6 (C8, C9, C10);
55.1 (CH2); 61.9, 56.2(MeO); d 24.4 (OC(CH3)O). FAB-
/
/
/
[dd, 1H, H5, J(H5P)ꢀ
5.9], 5.37 (s, 2H, CH2), 3.77 (s,
/
MS: m/zꢀ
/
852 [M]ꢁ; 366 [(Lꢂ
/
H)Pd]ꢁ.
3H, MeO), 3.62 (s, 3H, MeO). 31P{1H}-NMR (80.96
MHz, CDCl3, d ppm) 33.5 s. 13C{1H}-NMR (50.28
3.1.3. Preparation of [Pd{2,3-(MeO)2C6H2C(H)Ä
/
MHz, CDCl3, d ppm, J Hz): 171.9d, J(PC)ꢀ
(CÄN); 148.7, 148.2, 147.6 (C2, C3, C7); 140.1, 139.0
(C1, C6); 115.2d, J(PC)ꢀ5.6 Hz (C4); 132.5d, J(PC)ꢀ
11.4 Hz (C5); 127.9, 127.0, 126.1 (C8, C9, C10); 54.9
(CH2); 61.9, 55.6 (OMe). P-phenyl: Ci 130.4d, J(PC)ꢀ
35.4 Hz; Co 134.0d, J(PC)ꢀ12.1 Hz; Cm 128.4d,
J(PC)ꢀ10.6 Hz; Cp 130.7d, J(PC)ꢀ2.13 Hz.
/
3.5 Hz
NCH2(C4H3S)}(m-Cl)]2 (3)
/
An aq. solution of NaCl (ca. 10ꢂ2 M) was added
dropwise to a solution of 2 (68 mg, 0.08 mmol) in 15 cm3
of C3H6O. The resulting mixture was stirred for 24 h.
The yellow precipitate formed was filtered of, washed
with water and dried under vacuum to give complex 3 as
a yellow solid. Yield: 0.054 g, 85%. Anal. Found: C,
/
/
/
/
/
/
41.4; H, 3.7; N, 3.4. Calc. for C28H28Cl2N2O4Pd2S2: C,
1
3.1.6. [{Pd[2,3-(MeO)2C6H2C(H)Ä
/
41.8; H, 3.5; N, 3.5%. IR: n(CÄ
/
N), 1603 s cmꢂ1. H-
NCH2(C4H3S)](Cl)}2(m-Ph2P(CH2)4PPh2)] (6)
Yield: 0.010 g, 68%. Anal. Found: C, 54.2; H, 4.7; N,
2.1. Calc. for C56H56Cl2N2O4P2Pd2S2: C, 54.6; H, 4.6;
NMR (200 MHz, CDCl3, d ppm, J Hz): 8.08 (s, 1H,
Hi), 7.32 [dd, 1H, H10, J(H9H10)ꢀ5.4, J(H8H10)ꢀ
0.9)], 7.17 [d, 1H, H8, J(H8H9)ꢀ
2.9], 7.03 (dd, 1H,
H9), 6.98 [d, 1H, J(H4H5)ꢀ8.3], 6.70 (d, 1H) (H4,H5),
5.03 (s, 2H, CH2), 3.83 (s, 3H, MeO), 3.80 (s, 3H, MeO).
FAB-MS: m/zꢀ765 [Mꢂ
Cl]ꢁ; 366 [(LꢂH)Pd]ꢁ.
/
/
/
N, 2.3%. IR: n(CÄ
MHz, CDCl3, d ppm, J Hz): 8.38 [d, 1H, Hi J(HiP)ꢀ
7.8], 7.17 [d, 1H, H8, J(H8H9)ꢀ3.4], 7.01 [dd, 1H, H9,
J(H9H10)ꢀ4.9], 6.22 [d, 1H, H4, J(H4H5)ꢀ
8.3], 5.97
/
N), 1613 s cmꢂ1 1H-NMR (200
.
/
/
/
/
/
/
/
/
[dd, 1H, H5, J(H5P)ꢀ
5.9], 5.39 (s, 2H, CH2), 3.77 (s,
/
3.1.4. Preparation of [Pd{2,3-(MeO)2C6H2C(H)Ä
/
3H, MeO), 3.63 (s, 3H, MeO). 31P{1H}-NMR (80.96
NCH2(C4H3S)}(Cl)(PPh3)] (4)
MHz, CDCl3, d ppm): 34.5 s. 13C{1H}-NMR (50.28
PPh3 (6.0 mg, 0.022 mmol) was added to a suspension
of 3 (10.0 mg, 0.012 mmol) in C3H6O (15 cm3). The
mixture was stirred for 12 h and the solvent removed to
give a yellow solid which was recrystallized from
MHz, CDCl3, d ppm, J Hz): 171.8d, J(PC)ꢀ
(CÄN); 148.7, 148.2, 147.4 (C2, C3, C7); 140.1, 139.0
(C1, C6); 115.1, J(PC)ꢀ5.9 Hz (C4); 132.4d, J(PC)ꢀ
11.3 Hz (C5); 128.1, 127.1, 126.1 (C8, C9, C10); 54.8
(CH2); 61.8, 55.7 (OMe). P-phenyl: Ci 130.3d, J(PC)ꢀ
46.7 Hz; Co 134.3d, J(PC)ꢀ11.3 Hz; Cm 128.4d,
J(PC)ꢀ9.9 Hz; Cp 130.6d, J(PC)ꢀ1.42 Hz.
/
2.5 Hz
/
/
/
C3H6OÁ/C6H14. Yield: 0.012 g, 80%. Anal. Found: C,
/
57.9; H, 4.5; N, 1.9. Calc. for C32H29NSO2Pd2ClP: C,
/
1
57.8; H, 4.4; N, 2.1%. IR: n(CÄ
NMR (200 MHz, CDCl3, d ppm, J Hz): 8.43 [d, 1H, Hi
J(HiP)ꢀ 2.4], 7.03 [dd,
8.4], 7.18 [d, 1H, H8, J(H8H9)ꢀ
1H, H9, J(H9H10)ꢀ4.9], 6.19 [d, 1H, H4, J(H4H5)ꢀ
/
N), 1617 s cmꢂ1. H-
/
/
/
/
3.1.7. Preparation of [Pd{2,3-(MeO)2C6H2C(H)Ä
/
/
/
NCH2(C4H3S)}(PPh3)][CF3SO3] (7)
8.3], 5.96 [dd, 1H, H5, J(H5P)ꢀ
/
5.9], 5.42 (s, 2H, CH2),
3.80 (s, 3H, MeO), 3.63 (s, 3H, MeO). 31P{1H}-NMR
Silver trifluoromethanesulfonate (4.1 mg, 0.029
mmol) was added to a solution of 4 (10.5 mg, 0.029
mmol) in C3H6O (15 cm3). The resulting mixture was
stirred for 2 h, filtered through celite to remove the AgCl
precipitate and the solvent removed to give a yellow
(80.96 MHz, CDCl3, d ppm): 42.9 s. 13C{1H}-NMR
(50.28 MHz, CDCl3, d ppm, J Hz): 172.4d, J(PC)ꢀ
Hz (CÄN); 148.7, 148.2, 147.8 (C2, C3, C7); 141.12,
138.9 (C1, C6); 115.1d, J(PC)ꢀ6.4 Hz (C4); 133.1d,
J(PC)ꢀ10.6 Hz (C5); 128.3, 127.2, 126.1 (C8, C9, C10);
55.1 (CH2); 61.9, 55.6 (OMe). P-phenyl: Ci 131.1d,
J(PC)ꢀ49.7 Hz; Co 135.4d, J(PC)ꢀ12.0 Hz; Cm
/4.3
/
/
solid which was recrystallized from CH2Cl2ÁC6H14.
/
/
Yield: 0.090 g, 72%. Anal. Found: C, 50.4; H, 3.7; N,
2.1. Calc. for C33H29F3NO5PPdS2: C, 50.1; H, 3.8; N,
1
/
/
1.8%. IR: n(CÄ
/
N), 1619 s cmꢂ1. H-NMR (200 MHz,

168
A. Ferna´ndez et al. / Journal of Organometallic Chemistry 654 (2002) 162Á169
/
CDCl3, d ppm, J Hz, J Hz): 8.46 [d, 1H, Hi J(HiP)ꢀ
6.8], 7.14 [d, 1H, H8, J(H8H9)ꢀ3.4], 7.05 [dd, 1H, H9,
J(H9H10)ꢀ4.9], 6.22 [d, 1H, H4, J(H4H5)ꢀ
8.8], 5.94
/
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
/
/
[dd, 1H, H5, J(H5P)ꢀ
5.9], 5.23 (s, 2H, CH2), 3.88 (s,
/
3H, MeO), 3.66 (s, 3H, MeO). 31P{1H}-NMR (80.96
MHz, CDCl3, d ppm): 41.2 s. 13C{1H}-NMR (50.28
de la Coruna for financial support.
˜
MHz, CDCl3, d ppm): 173.1 (CÄ
C3); 141.8 (C7); 140.7, 138.5 (C1, C6); 115.3d, J(PC)ꢀ
6.4 Hz (C4); 133.2d, J(PC)ꢀ7.1 Hz (C5); 127.7, 127.2,
125.8 (C8, C9, C10); 57.5 (CH2); 62.0, 55.6 (OMe). P-
phenyl: Ci 130.4d, J(PC)ꢀ46.8 Hz; Co 134.0d,
J(PC)ꢀ11.3 Hz; Cm 128.3d, J(PC)ꢀ9.9 Hz; Cp
130.6. FAB-MS: m/zꢀ628 [Mꢂ
SO3CF3]ꢁ. Specific
molar conductivity, Lmꢀ
145.1 ohmꢂ1 cm2 molꢂ1 (in
MeCN).
/
N); 149.7, 149.0 (C2,
/
References
/
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/
0.0320, 0.0296 and 0.0588 (for complexes 2, 4
0.0836,
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˜
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/
Chem. Soc. Dalton Trans. (1999) 4193.
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/
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/
44-1223-336033; e-mail: deposit@ccdc.cam.a-
c.uk or www: http://www.ccdc.cam.ac.uk).

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¨