Cylometallated semicarbazone complexes of palladium(II). Crystal and molecular structure of [{Pd[C6H4C(Et)=NN(H)C(=O)NH2]} 2(μ-Ph2P(CH2)3PPh 2)][ClO4]2

Article abstract of DOI:10.1016/S0022-328X(97)00668-2

Treatment of the semicarbazones 4-MeC₆H₄C(Me)=NN(H)C(=O)NH₂ a, 3,4-Me₂C₆H₃C(Me)=NN(H)C(=O)NH₂ b and C₆H₅C(Et)=NN(H)C(=O)NH₂ c, gave the [C,N,O] cyclometallated compounds [Pd{4-MeC₆H₃C(Me)=NN(H)C(=O)NH₂}(Cl)] 1a, [Pd{3,4-Me₂C₆H₂C(Me)=NN(H)C(=O)NH ₂}(Cl)] 1b and [Pd{C₆H₄C(Et)=NN(H)C(=O)NH₂}(Cl)] 1c, after C-H activation. Treatment of compounds 1a, 1b, and 1c with silver perchlorate followed by treatment with tertiary diphosphine ligands gave the dinuclear [C,N,O] cyclometallated compounds [{Pd[4-MeC₆H₃C(Me)=NN(H)C(=O)NH₂]} ₂(μ-L)][ClO₄]₂ 2a-7a, [{Pd[3,4-Me₂C₆H₂C(Me)=NN(H)C(=O)NH ₂]}₂(μ-L)][ClO₄]₂ 2b-7b, [{Pd[C₆H₄C(Et)=NN(H)C(=O)NH₂]} ₂(μ-L)][ClO₄]₂ 2c-7c, [L=Ph₂P(CH₂)₄PPh₂ (dppb), Ph₂P(CH₂)₃PPh₂ (dppp), Ph₂P(CH₂)₂PPh₂ (dppe), trans-Ph₂PCH=CHPPh₂ (trans-dppe), Ph₂PC(=CH₂)PPh₂ (vdpp) and Ph₂PCH₂PPh₂ (dppm)] as 1:2 electrolytes. Reaction of 1a and 1c with diphosphines gave the dinuclear [C,N] cyclometallated compounds [{Pd[4-MeC₆H₃C(Me)=NN(H)C(=O)NH₂](Cl)} ₂(μ-L)] 8a, 9a, [{Pd[C₆H₄C(Et)=NN-(H)C(=O)NH₂](Cl)} ₂(μ-L)] 8c, 9c, [L=Ph₂P(CH₂)₃PPh₂ (dppp) and Ph₂P(CH₂)₄PPh₂ (dppb)]. The complexes were characterised by their elemental analysis (C,H,N) and by IR and ³¹P{¹H} and ¹H-NMR data, and [{Pd[C₆H₄C(Et)=NN(H)C(=O)NH₂]} ₂(μ-Ph₂P(CH₂)₃PPh ₂)][ClO₄]₂ (3c) was characterised crystallographically.

Full text of DOI:10.1016/S0022-328X(97)00668-2

Journal of Organometallic Chemistry 556 (1998) 21–30
Cylometallated semicarbazone complexes of palladium(II). Crystal and
molecular structure of
[{Pd[C6H4C(Et)ꢀNN(H)C(ꢀO)NH2]}2(v-Ph2P(CH2)3PPh2)][ClO4]2
Jose´ M. Vila a,*, Teresa Pereira a, Juan M. Ortigueira a, Margarita Lo´pez Torres a,
Alfonso Castin˜eiras a, D. Lata a, Jesu´s J. Ferna´ndez b, Alberto Ferna´ndez b
a Departamento de Qu´ımica Inorga´nica, Uni6ersidad de Santiago de Compostela, 15706 Santiago de Compostela, Spain
b Departamento de Qu´ımica Fundamental e Industrial, Uni6ersidad de La Corun˜a, 15071 La Corun˜a, Spain
Received 5 August 1997
Abstract
Treatment of the semicarbazones 4-MeC6H4C(Me)ꢀNN(H)C(ꢀO)NH2 a, 3,4-Me2C6H3C(Me)ꢀNN(H)C(ꢀO)NH2
b and
C6H5C(Et)ꢀNN(H)C(ꢀO)NH2 c, gave the [C,N,O] cyclometallated compounds [Pd{4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)NH2}(Cl)] 1a,
[Pd{3,4-Me2C6H2C(Me)ꢀNN(H)C(ꢀO)NH2}(Cl)] 1b and [Pd{C6H4C(Et)ꢀNN(H)C(ꢀO)NH2}(Cl)] 1c, after CꢁH activation. Treat-
ment of compounds 1a, 1b, and 1c with silver perchlorate followed by treatment with tertiary diphosphine ligands gave the
dinuclear [C,N,O] cyclometallated compounds [{Pd[4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)NH2]}2(v-L)][ClO4]2 2a–7a, [{Pd[3,4-
Me2C6H2C(Me)ꢀNN(H)C(ꢀO)NH2]}2(v-L)][ClO4]2 2b–7b, [{Pd[C6H4C(Et)ꢀNN(H)C(ꢀO)NH2]}2(v-L)][ClO4]2 2c–7c, [L=
Ph2P(CH2)4PPh2 (dppb), Ph2P(CH2)3PPh2 (dppp), Ph2P(CH2)2PPh2 (dppe), trans-Ph2PCHꢀCHPPh2 (trans-dppe),
Ph2PC(ꢀCH2)PPh2 (vdpp) and Ph2PCH2PPh2 (dppm)] as 1:2 electrolytes. Reaction of 1a and 1c with diphosphines gave the
dinuclear
[C,N]
cyclometallated
compounds
[{Pd[4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)NH2](Cl)}2(v-L)]
8a,
9a,
[{Pd[C6H4C(Et)ꢀNNꢁ(H)C(ꢀO)NH2](Cl)}2(v-L)] 8c, 9c, [L=Ph2P(CH2)3PPh2 (dppp) and Ph2P(CH2)4PPh2 (dppb)]. The com-
plexes were characterised by their elemental analysis (C,H,N) and by IR and 31P{1H} and 1H-NMR data, and
[{Pd[C6H4C(Et)ꢀNN(H)C(ꢀO)NH2]}2(v-Ph2P(CH2)3PPh2)][ClO4]2 (3c) was characterised crystallographically. © 1998 Elsevier
Science S.A. All rights reserved.
Keywords: Cyclometallated; Semicarbazone; Palladium
1. Introduction
come interested in the synthesis and reactivity of
palladium and platinum cyclometallated compounds
with potentially terdentate [C,N,N] ligands and we have
described some chemistry of these ligands related to
their reactivity with tertiary phosphines and diphosphi-
nes [10] J.M. Vila, M. Gayoso, M.T. Pereira, M. Lo´pez
Torres, J.J. Ferna´ndez, A. Ferna´ndez, and J.M. Or-
tigueira (Unpublished results). It is our purpose to
extend our research to the related terdentate [C,N,O]
systems, in particular semicarbazones, which should
produce cyclometallated complexes in which the ligand
is bonded through carbon, nitrogen and oxygen, giving
compounds with two fused rings; examples of other
Since the first cyclometallated complex was described
cyclometallation has become very important in
organomeAtallic chemistry [1–5] and in associated ar-
eas such as in regioespecific organic and organometallic
reactions [6], in insertion reactions [7], in the synthesis
of new metal mesogenic compounds [8], and in catalytic
materials [9]. Nitrogen-donor ligands are known to
undergo facile metallation with formation of the classi-
cal five-membered metallacycle. Recently we have be-
* Corresponding author.
0022-328X/98/$19.00 © 1998 Elsevier Science S.A. All rights reserved.
PII S0022-328X(97)00668-2

22
J.M. Vila et al. / Journal of Organometallic Chemistry 556 (1998) 21–30
terdentate [C,N,O] systems have been reported [11–13].
In the present paper we report the synthesis and reac-
tivity of new semicarbazone cyclometallated com-
pounds with bonds at palladium to the aryl carbon,
imine nitrogen and oxygen atoms. We considered that
removal of the chlorine at palladium by treatment with
silver perchlorate, should render a vacant coordination
site which could be occupied by the phosphine giving
compounds with the two fused rings intact, whereas
treatment with the phosphine in the absence of the
silver salt should give ring openning reactions, and this
is what we have done. In either case novel dinuclear
complexes may be obtained with the diphosphines
Ph2P(CH2)4PPh2 (dppb), Ph2P(CH2)3PPh2 (dppp),
pounds
(v-L)][ClO4]2
[{Pd[4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)NH2]}2-
2a–7a, [{Pd[3,4-Me2C6H2Cꢁ(Me)ꢀ
NN(H)C(ꢀO)NH2]}2(v-L)][ClO4]2 2b–7b, [{Pd[C6H4C–
(Et)ꢀNN(H)C(ꢀO)NH2]}2(v-L)][ClO4]2 2c–7c, [L=
Ph2PCH2PPh2 (dppm), Ph2P(CH2)2PPh2 (dppe),
Ph2P(CH2)3PPh2 (dppp) and Ph2P(CH2)4PPh2 (dppb)
Ph2PC((CH2)PPh2 (vdpp) and trans-Ph2PCHꢀCHPPh2
(trans-dppe)], in which the diphosphine ligand bridges
two metal centers which are in turn bonded to a
terdentate semicarbazone [C,N,O] system. The com-
pounds were pure air-stable solids, which were fully
characterised (see Section 3 and Table 1); they are
soluble in the more common organic solvents. They are
1:2 electrolytes as was shown by molar conductivity
measurements in dry acetonitrile. The chlorine atom
has been quantitatively removed as silver chloride, as is
confirmed by the absence of the w(PdCl) band in the IR
spectra, to yield compounds with the metal center
bonded to four different atoms in a square-planar
environment. The H5 resonance shows a high-field shift
and coupling to the 31P atom (see Table 1); for com-
pounds with dppe, dppp and dppb, this signal is a
doublet or a doublet of doublets, as is the case; whereas
in compounds with dppm, vdpp, and trans-dppe, the
Ph2P(CH2)2PPh2
(trans-dppe),
(dppe),
Ph2PC(ꢀCH2)PPh2
trans-Ph2PCHꢀCHPPh2
(vdpp) and
Ph2PCH2PPh2 (dppm) bridging the two palladium cen-
tres. The X-ray crystal structure of one of these com-
pounds is reported.
2. Results and discussion
2.1. Reactions of the ligands
resonance appears as a multiplet. The H{31P} spectra
1
brings the H5 resonance to a singlet in the a and b
complexes, and to a doublet of doublets in the c
complexes.
Treatment of compunds 1a, 1b and 1c with the
appropriate tertiary diphosphine in a 2:1 molar ratio
The compounds described in this paper were charac-
terised by elemental analysis and by IR spectroscopy
1
(data in Section 3) and by H and 31P{1H} (Table 1)
and 13C-NMR spectroscopy (for the free ligands and
1a, 1b and 1c only; Section 3). Treatment of the semi-
carbazone ligands a, b or c with Li2[PdCl4] in methanol
gave
the
dinuclear
compounds
[{Pd[4-
MeC6H3C(Me)ꢀNN(H)C(ꢀO)NH2](Cl)}2(v-L)] 8a, 9a,
[{Pd[C6H4C(Me)ꢀNNꢁ(H)C(ꢀO)NH2](Cl)}2(v-L)] 8c,
9c, [8a, 8c: L=Ph2P(CH2)4PPh2 (dppp); 9a: L=
Ph2P(CH2)2PPh2 (dppe); 9c: L=Ph2P(CH2)3PPh2
(dppp)], in which the diphosphine ligand bridges two
metal centers which are bonded to a bidentate semicar-
bazone [C,N] system. The compounds were air-stable
solids, which were fully characterised (see Section 3 and
Table 1); compounds 8a and 9a were too insoluble for
their NMR determination. The low values of the molar
conductivity measurements in dry acetonitrile, pre-
cludes their formulation as electrolyte species. The
w(CꢀO) stretch clearly shows there is no PdꢁO bond in
the complexes; as proof, in 8c and 9c the NH resonance
is not low field shifted with respect to the free ligand
(vide supra). The shift of the w(PdꢁCl) stretch towards
lower wavenumbers suggests the chlorine atom is trans
to the higher trans influence aryl carbon atom. Also
noticable is the higher value of J[PH(5)] in the H-
NMR spectra of 8c and 9c as compared to the
analogous electrolyte compounds, 2c and 3c.
Reaction of compounds 8a, 8c, 9a, 9c with silver
perchlorate gave removal of the chlorine ligand and
rearrangement of the compounds to yield complexes 2a,
2c, 4a, 3c, respectively, with the palladium atom
bonded to a terdentate [C,N,O] system.
gave
compounds
[Pd{4-MeC6H3C(Me)ꢀNN(H)C-
(ꢀO)NH2}(Cl)] 1a, [Pd{3,4-Me2C6H2C(Me)ꢀNN(H)C-
(ꢀO)NH2}(Cl)] 1b and [Pd{C6H3C(Et)ꢀNNꢁ(H)C-
(ꢀO)NH2}(Cl)] 1c, respectively (Scheme 1). The metal-
lated organic moiety is bonded to the palladium atom
in each case through the aryl C6 carbon atom, the
imine nitrogen atom, and the oxygen atom. The lower
frequency shift of the w(CꢀO) band is in accordance
with coordination of the amide oxygen to the metal
center ([14]a,b). The w(PdCl) values confirm the trans
geometry of the chlorine atom with respect to the imine
nitrogen. The compounds were sufficiently soluble in
DMSO-d6, although some signals were broad in the
1H-NMR spectra. Nevertheless, the NH resonance
could be correctly assigned, and it is shifted to lower
field in agreement with coordination of the C(ꢀO)NH
group to palladium [13]. This shift is not observed in
compounds where the PdꢁO bond has been cleaved
(vide infra). The CꢀO, CꢀN, C1 and C6 resonances in
the 13C-NMR spectra are downfield shifted from those
of the parent free ligands, confirming metallation and
PdꢁN coordination had taken place [15].
4
1
Treatment of compounds 1a, 1b and 1c with silver
perchlorate followed by the appropriate tertiary diphos-
phine in a 2:1 molar ratio gave the dinuclear com-

J.M. Vila et al. / Journal of Organometallic Chemistry 556 (1998) 21–30
23
Table 1
31Pa and 1Hb-NMR datac,d
Compound 31P
Aromatic
Others
ae
7.59[d, 2H, H2, H6, 8.3f]
7.19[d, 2H, H3, H5, 8.3f]
9.32[s, 1H, NH]
6.48[s, 2H, NH2]
2.38[s, 3H, Me]
2.22[s, 3H, Me]
10.2[br, 1H, NH]
2.21[s, 3H, Me]
2.18[s, 3H, Me]
10.8[br, 1H, NH]
7.0[br, 2H, NH2]
2.35[s, 3H, Me]
1.85[s, 3H, Meh]
10.8[br, 1H, NH]
7.0[br, 2H, NH2]
2.36[s, 3H, Me]
1.80[s, 3H, Meh]
10.13[d, 1H, NH, 4.0i]
7.0[br, 2H, NH2]
1.76[s, 3H, Meh]
10.8[br, 1H, NH]
6.9[br, 2H, NH2]
2.38[s, 3H, Me]
1.79[s, 3H, Meh]
10.6[br, 1H, NH]
6.8[br, 2H, NH2]
2.34[s, 3H, Me]
1.78[s, 3H, Meh]
10.8[br, 1H, NH]
2.37[s, 3H, Me]
1.60[s, 3H, Meh]
9.25[s, 1H, NH]
6.47[s, 2H, NH2]
2.30[s, 3H, Me]
2.29[s, 3H, Me]
2.19[s, 3H, Me]
10.1[br, 1H, NH]
2.17[s, 3H, Me]
2.19[s, 3H, Me]
10.5[br, 1H, NH]
6.8[br, 2H, NH2]
2.35[s, 3H, Me]
2.08[s, 3H, Me]
1.77[s, 3H, Meh]
10.7[br, 1H, NH]
6.4[br, 2H, NH2]
2.37[s, 3H, Me]
1.74[s, 3H, Meh]
10.14[d, 1H, NH, 4.2i]
6.9[br, 2H, NH2]
1.69[s, 3H, Meh]
10.8[br, 1H, NH]
6.9[br, 2H, NH2]
2.41[s, 3H, Me]
2.12[s, 3H, Me]
1.72[s, 3H, Meh]
10.5[m, 1H, NH]
6.6[br, 2H, NH2]
2.31[s, 3H, Me]
2.13[s, 3H, Me]
1.63[s, 3H, Meh]
10.8[br, 1H, NH]
7.1[br, 2H, NH2]
2.35[s, 3H, Me]
1ae
2a
7.15–6.84 m
32.1s
32.1s
7.12[d,1H, H2, 7.6f]
6.84[d, 1H, H3, 7.6f]
6.08[d, 1H, H5, 4.1g]
3a
7.12[d,1H, H2, 7.8f]
6.82[d, 1H, H3, 7.8f]
6.05[d, 1H, H5, 5.0g]
4a
5a
32.9s
32.8s
7.01[d,1H, H2, 7.7f]
6.80[d, 1H, H3, 7.7f]
5.57[d, 1H, H5, 4.0g]
7.12[d,1H, H2, 8.0f]
6.85[d, 1H, H3, 8.0f]
6.08[m, 1H, H5]
6ak
41.8s
27.0s
7.05[d,1H, H2, 7.6f]
6.81[d, 1H, H3, 7.6f]
5.95[m, 1H, H5]
7al
bl
6.86[d,1H, H2, 7.7f]
6.52[d, 1H, H3, 7.7f]
5.97[m, 1H, H5]
7.45[s,1H, H2]
7.40[d, 1H, H6, 7.7f]
7.14[d, 1H, H5, 7.7f]
1be
2b
7.1–6.8m
28.5s
32.2s
6.48[s,1H, H2]
5.83[d, 1H, H5, 5.1f]
3b
7.05[s,1H, H2]
5.98[d, 1H, H5, 5.0f]
4b
5b
32.5s
36.7s
6.89[s,1H, H2]
5.49[d, 1H, H5, 5.3f]
7.07[s,1H, H2]
6.03[m, 1H, H5]
6b
42.2s
27.2s
6.97[s,1H, H2]
5.97[m, 1H, H5]
7bl
6.75[s,1H, H2]
5.87[m, 1H, H5]

24
J.M. Vila et al. / Journal of Organometallic Chemistry 556 (1998) 21–30
Table 1 (continued)
Compound 31P
Aromatic
Others
1.95[s, 3H, Me]
1.49[s, 3H, Meh]
9.64[s, 1H, NH]
6.57[s, 2H, NH2]
2.72[q, 2H, Et, 7.8f]
1.19[t, 3H, Et, 7.8f]
10.6[br, 1H, NH]
2.63[q, 2H, Et, 7.5f]
1.11[t, 3H, Et, 7.5f]
11.1[s, 1H, NH]
ce
7.82[dd, 1H, H2, 7.8f, 1.4m]
7.36[m, H3, H4, H5, H6]
1ce
2c
7.3–6.9m
33.1s
26.7s
30.6s
31.8s
30.95s
7.26[dd, 1H, H2, 7.6f, 1.3m]
7.03[t, 2H, H3, 7.6f]
7.1[s, 2H, NH2]
6.71[dt, 1H, H4, 7.6f, 1.3m]
6.38[dd, 1H, H5, 7.8f, 5.2g]
7.30[dd, 1H, H2, 7.6f, 1.4m]
7.05[t, 1H, H3, 7.6f]
2.84[q, 2H, Et, 7.6f]
1.25[t, 3H, Et, 7.6f]
10.91[d, 1H, NH, 4.2i]
7.1[br, 2H, NH2]
1.25[t, 3H, Et, 7.6f]
3c
6.73[dt, 1H, H4, 7.6f, 1.4m]
6.39[dd, 1H, H5, 7.8f, 5.4g]
7.20[dd, 1H, H2, 7.6f, 1.4m]
7.02[t, 1H, H3, 7.6f]
4c
10.7[br, 1H, NH]
7.0[br, 2H, NH2]
2.68[q, 2H, Et, 7.5f]
1.20[t, 3H, Et, 7.5f]
10.9[br, 1H, NH]
7.0[br, 2H, NH2]
1.20[t, 3H, Et, 7.6f]
6.62[dt, 1H, H4, 7.6f, 1.4m]
6.13[dd, 1H, H5, 7.6f, 5.8g]
7.31[dd, 1H, H2, 7.6f, 1.4m]
7.05[t, 1H, H3, 7.6f]
5c
6.64[dt, 1H, H4, 7.6f, 1.4m]
6.35[m, 1H, H5, 7.6f]
6cj,k
7.0–6.9[m, 2H, H2, H3]
6.46[dt, 1H, H4, 7.6f, 1.7m]
5.95[m, 1H, H5, 7.6f]
10.4[br, 1H, NH]
5.2[br, 2H, NH2]
2.63[q, 2H, Et, 7.6f]
1.22[t, 3H, Et, 7.6f]
11.0[br, 1H, NH]
2.79[q, 2H, Et, 7.6f]
1.25[t, 3H, Et, 7.6f]
9.2[br, 1H, NH]
6.76[br, 2H, NH2]
2.68[q, 2H, Et, 7.5f]
1.50[t, 3H, Et, 7.5f]
9.3[br, 1H, NH]
7cl
21.1s
37.2s
6.95[d, 1H, H2, 7.6f]
6.67[m, 2H, H3, H4]
6.2[m, 1H, H5]
8ce
7.36[d, 1H, H2, 7.3f]
6.94[t, 1H, H3, 7.3f]
6.56[t, 1H, H4, 7.3f]
6.30[t, 1H, H5, 7.3f, 7.3g]
7.35[d, 1H, H2, 7.3f]
6.95[t, 1H, H3, 7.3f]
6.57[t, 1H, H4, 7.3f]
6.27[t, 1H, H5, 7.3f, 7.3g]
9ce
34.9s
6.89[br, 2H, NH2]
2.65[q, 2H, Et, 7.5f]
1.55[t, 3H, Et, 7.5f]
a In (CD3)2CO unless otherwise stated. Measured at 100.6 MHz (ca. 20°C); chemical shifts (l) in ppm (90.1) to high frequency of 85% H3PO4.
b In (CD3)2CO unless otherwise stated. Measured at 250 or 300 MHz; chemical shifts (l) in ppm ((0.01) to high frequency of SiMe4.
c Coupling constants in Hz.
d s, singlet; d, doublet; dd, doublet of doublets; t, triplet; dt doublet of triplets; q, quadruplet; m, multiplet; br, broad.
e In DMSO-d6.
f 3 J(HH).
g 4 J(PH5).
h C(3)ꢁMe.
i 4 J(PH).
j In CDCl3.
k l([PC(.CH2)P]: (6a), 7.18, N=43; (6c), 7.16, N=46.
l [(PCH2P)]: (7a), 4.42m; (7b), 4.2m; (7c), 4.46 m.
m 4 J(HH).
2.2. Crystal structure of [{Pd[C6H4C(Et)ꢀNN(H)C-
(ꢀO)NH2]}2(v-Ph2Pꢁ(CH2)3PPh2)][ClO4]2 3c
are given in Table 2. Fractional coordinates and
isotropic thermal parameters are listed in Table 3.
Selected bond lengths and bond angles with estimated
standard deviations are listed in Table 4.
The crystal structure comprises a centrosymmetric
dinuclear cation (half of the cation per asymmetric
Suitable crystals of the title compound were grown
from slowly evaporating a chloroform solution. The
molecular structure is illustrated in Fig. 1. Crystal data

J.M. Vila et al. / Journal of Organometallic Chemistry 556 (1998) 21–30
25
Scheme 1. Treatment of the semicarbazone ligands a, b or c with Li2[PdCl4] in methanol (i) gave compounds 1a–c, which were further reacted
(ii) to give 2–7 or (iii) 8, 9 followed by (iv) resulting in 2–7.
respectively. Angles between planes are as follows:
plane 1/plane 2, 5.5°; plane 1/plane 3, 6.7°; plane
2/plane 3, 3.8°.
unit), and two perchlorate anions. Each four-coordi-
nated palladium(II) is bonded to a terdentate semicar-
bazone system through the aryl C(1) carbon, the imine
N(1) nitrogen and the amide O oxygen atoms, and to a
phosphorus atom of a 1,3-bis(diphenylphosphine)pro-
pane, which bridges a crystallographic inversion center
between the two metal atoms.
3. Experimental details
˚
The PdꢁN(1) bond length of 1.98(2) A is within the
3.1. Materials and instrumentation
expected value based on the sum of the covalent radii
2
˚
˚
[16] for palladium (1.31 A) and nitrogen (sp ) (0.7 A)
Solvents were purified by standard methods [17].
Chemicals were reagent grade. Palladium(II) chloride
was a generous loan by Johnson Matthey. The phosphi-
nes Ph2PCH2PPh2 (dppm), Ph2P(CH2)2PPh2 (dppe),
Ph2P(CH2)3PPh2 (dppp) and Ph2P(CH2)4PPh2 (dppb)
were purchased from Aldrich-Chemie; Ph2PC(ꢀCH2)-
PPh2 (vdpp) and trans-Ph2PCHꢀCHPPh2 (trans-dppe)
were prepared according to procedures described else-
where [18]. Microanalyses were carried out at the Servi-
cio de Ana´lisis Elemental at the University of Santiago
using a Carlo Erba Elemental Analyser, Model 1108.
NMR spectra were obtained as CDCl3 DMSO-d6 or
(CD3)2CO solutions and referenced to SiMe4 (1H, 13C)
or 85% H3PO4 (31P{1H}) and were recorded on Bruker
WM250, and AMX-300 spectrometers. All chemical
shifts were reported downfield from standards.
and similar to others reported [13]. The PdꢁC(1),
˚
2.00(2), and PdꢁP, 2.246(7) A, bond lengths are some-
what shorter than the values predicted from their cova-
lent radii [16], and they are similar to values found
˚
earlier [13]. The PdꢁO length, 2.15 A, is longer then the
˚
expected value of 1.97 A, and shows the trans influence
of the aryl carbon atom. The sum of angles about the
palladium atom is 360.4°, with the only noteworthy
deviation being the somewhat reduced [N(1)ꢁPdꢁC(1)]
bond angle consequent upon chelation, which is
reflected in the the value of the PdꢁC(1)ꢁC(6), 130.8°,
angle.
The geometry around the palladium atom is planar
˚
(r.m.s.=0.0692 A; plane 1). The metallated ring [Pd,
C(1), C(2), C(7), N(1)] and the coordination ring
[Pd,N(1), N(2), C(8), O(1)] are also planar (r.m.s.=
0.0189 A; plane 2) and (r.m.s.=0.0289 A; plane 3),
The
synthesis
of
the
semicarbazones
4-
˚
˚
MeC6H4C(Me)ꢀNN(H)C(ꢀO)NH2 (a), 3,4-Me2C6H3C-

26
J.M. Vila et al. / Journal of Organometallic Chemistry 556 (1998) 21–30
Fig. 1. Molecular structure of [{Pd[C6H4C(Et)ꢀNN(H)C(ꢀO)NH2]}2(v-Ph2Pꢁ(CH2)3PPh2)][ClO4]2.
(Me)ꢀNN(H)C(ꢀO)NH2 (b) and C6H5C(Et)ꢀNN(H)C-
(ꢀO)NH2 (c) was performed according to methods de-
scribed in the literature [19]. 13C-{1H}NMR (75.48
MHz DMSO-d6): a, l 157.8 (CꢀO); l 144.5 (CꢀN); l
135.9 (C4); l 129.1 (C3, C5); l 126.2 (C2, C6); l 21.1,
13.6 (Me); b, l 157.7 (CꢀO); l 144.5 (CꢀN); l 127.24
(C6); l 137.0, 136.3, 136.2 (C1, C3, C4); l 123.8 (C2);
l 129.6 (C5); l 19.5, 19.7, 13.6 (Me); c, l 157.7 (CꢀO);
l 148.5 (CꢀN); l 137.2 (C1); l 128.5, 128.4, 126.1 (C2,
C3, C4, C5, C6); l 18.9 (CH2CH3); l 10.5 (CH2CH3).
13C-{1H}NMR (62.46 MHz DMSO-d6): l 166.0 (CꢀO);
l 159.8 (CꢀN); l 149.7 (C6); l 144.6 (C1); l 139.3 (C4);
l 137.8 (C5); l 129.14, 126.2 (C2, C3): l 21.9, 14.2
(Me).
Compounds 1b and 1c were obtained following a
similar procedure as yellow solids.
3.2.2. [Pd{3,4-Me2C6H2C(Me)ꢀNN(H)C(ꢀO)NH2}(Cl)]
1b
Yield 85%. Anal. Found: C, 38.0; H, 4.0; N, 11.8.
C11H14N3OClPd Calc.: C, 38.2; H, 4.1; N, 12.1%. IR:
w(CꢀO) 1649s, w(CꢀN) 1628s, w(PdꢁCl) 332w cm−1.
13C-{1H}NMR (62.46 MHz DMSO-d6): l (CꢀO); l
(CꢀN); l (C6); l 145.2 (C1); l 137.7, 135.9, 132.7,
131.9, 122.0 (C2, C3, C4, C5); l 20.13, 11.17 (Me).
3.2. Preparations
3.2.1. [Pd{4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)NH2}(Cl)]
1a
To a stirred solution of lithium tetrachloropalladate
in 50 ml of methanol, prepared in situ from 200 mg
(1.13 mmol) of palladium(II) chloride and 100 mg (2.33
mmol) of lithium chloride, 100 mg (1.22 mmol) of
sodium acetate and 240 mg (1.25 mmol) of the semicar-
bazone 4-MeC6H4C(Me)ꢀNN(H)C(ꢀO)NH2 (a) were
added. The mixture was stirred for 48 h at room
temperature. The precipitate was filtered off and
washed with methanol. The solid was added to 50 ml of
ethanol and heated to reflux. The hot mixture was
filtered and the pale-yellow solid resulting dried in air.
Yield 80%. Anal. Found: C, 36.4; H, 3.7; N, 12.4.
C10H12N3OClPd Calc.: C, 36.2; H, 3.6; N, 12.6%. IR:
3.2.3. [Pd{C6H4C(Et)ꢀNN(H)C(ꢀO)NH2}(Cl)] 1c
Yield 73%. Anal. Found: C, 36.1; H, 3.8; N, 12.6.
C10H12N3OClPd Calc.: C, 36.2; H, 3.6; N, 12.6%. IR:
w(CꢀO) 1645s, w(CꢀN) 1616s, w(PdꢁCl) 347w cm−1
.
13C-{1H}NMR (62.46 MHz DMSO-d6): l (CꢀO); l
(CꢀN); l 150.0 (C6); l 146.7 (C1);l 135.0 (C5); l 129.4,
126.9, 124.7 (C2, C3, C4); l 20.13 (CH2CH3); l 11.2
(CH2CH3).
3.2.4. [{Pd[4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)-
NH2]}2(v-Ph2P(CH2)4PPh2)][ClO4]2 2a
A suspension of 1a (50 mg, 0.15 mmol) in acetone (15
w(CꢀO) 1670s, w(CꢀN) 1620s, w(PdꢁCl) 340w cm−1
.
cm3) was treated with silver perchlorate (32 mg) and

J.M. Vila et al. / Journal of Organometallic Chemistry 556 (1998) 21–30
27
Table 3
stirred for 2 h. The solution was filtered through Celite
to eliminate the AgCl precipitate. Ph2P(CH2)4PPh2 (32
mg, 0.08 mmol) was added to the filtrate and the
solution stirred for 4 h, the solvent removed and the
product recrystallized from dichloromethane/hexane to
give the desired complex as a white solid. Yield 82%.
Anal. Found: C, 47.6; H, 4.3; N, 7.1.
C48H52N6O10Cl2Pd2P2 Calc.: C, 47.3; H, 4.3; N, 6.9%.
IR: w(CꢀO) 1651m, w(CꢀN) 1631sh cm−1. Specific mo-
lar conductivity, Lm=250 ohm−1 cm2 mol−1 (in ace-
tonitrile).
Atomic coordinates and equivalent isotropic displacement parameters
2
˚
(A ) for 3c
x
y
z
Biso
Pd
Cl
P
O
0.35502(7)
0.0631(3)
0.3763(2)
0.4051(6)
0.0833(9)
0.043(2)
0.024(2)
0.110(2)
0.3473(7)
0.3781(7)
0.4356(8)
0.2996(7)
0.2903(8)
0.2508(9)
0.2247(9)
0.235(1)
0.2729(9)
0.3176(9)
0.317(1)
0.367(1)
0.4051(8)
0.4037(7)
0.4189(9)
0.445(1)
0.456(1)
0.438(1)
0.414(1)
0.3162(8)
0.267(1)
0.218(1)
0.219(1)
0.263(1)
0.314(1)
0.4430(9)
0.500
0.6949(2)
0.2399(7)
0.6142(5)
0.567(1)
0.271(2)
0.126(4)
0.324(5)
0.271(4)
0.771(2)
0.710(2)
0.538(2)
0.839(2)
0.911(2)
1.015(2)
1.048(2)
0.976(2)
0.873(2)
0.874(2)
0.946(2)
1.043(3)
0.604(2)
0.716(2)
0.833(2)
0.903(3)
0.850(3)
0.740(2)
0.664(2)
0.517(2)
0.573(2)
0.497(3)
0.374(2)
0.318(3)
0.393(2)
0.515(2)
0.590(3)
0.11584(7) 2.68(3)
0.6070(3)
0.2115(2)
0.0920(6)
0.672(1)
0.584(2)
0.559(2)
0.599(2)
0.0375(7)
0.0111(7)
0.0200(8)
0.1034(9)
0.0505(9)
0.033(1)
0.069(1)
0.120(1)
0.138(1)
0.014(1)
5.8(2)
2.5(1)
4.1(4)
9.3(7)
21(2)
O(1)
O(2)
O(3)
O(4)
N(1)
N(2)
N(3)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(31)
C(32)
24(2)
19(1)
Compounds 3a–7a, 2b–7b and 2c–7c,were synthe-
sized following a similar procedure as white or yellow
solids.
4.0(5)
3.8(4)
4.8(6)
2.2(5)
3.0(5)
4.2(6)
4.9(7)
4.6(7)
3.7(5)
3.8(6)
4.8(7)
8.1(9)
4.2(6)
2.3(4)
4.1(5)
5.5(7)
5.3(6)
4.6(6)
4.5(6)
3.1(4)
4.3(6)
4.9(6)
4.7(6)
6.4(7)
4.7(6)
3.5(5)
2.0(5)
3.2.5. [{Pd[4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)-
NH2]}2(v-Ph2P(CH2)3PPh2)][ClO4]2 3a
Yield 90%. Anal. Found: C, 46.8; H, 4.1; N, 6.8.
C47H50N6O10Cl2Pd2P2. Calc.: C, 46.8; H, 4.2; N, 7.0%.
IR: w(CꢀO) 1651s, w(CꢀN) 1637sh cm−1. Specific molar
conductivity, Lm=300 ohm−1 cm2 mol−1 (in acetoni-
trile).
−0.040(1)
−0.013(1)
0.043(1)
0.2828(8)
0.281(1)
0.340(1)
0.396(1)
0.396(1)
0.341(1)
0.2094(9)
0.213(1)
0.204(1)
0.195(1)
0.188(1)
0.196(1)
0.2343(9)
0.250
Table 2
Crystal data for 3c
Empirical formula
C47H50Cl2N6O10
P2Pd2
Formula weight
Crystal system
Space group
1204.6
Monoclinic
C2/c
Unit cell dimensions
˚
a (A)
25.044(7)
10.847(1)
24.034(7)
˚
b (A)
˚
c (A)
i (°)
Volume
Z
121.83(3)
5547(5) A
4
1.442
8.477
2440
3
˚
Dcalc. (g cm−3
)
Absorption coefficient (cm−1
F(000)
)
3.2.6. [{Pd[4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)-
NH2]}2(v-Ph2P(CH2)2PPh2)][ClO4]2 4a
Yield 74%. Anal. Found: C, 46.3; H, 4.3; N, 7.0.
C46H48N6O10Cl2Pd2P2. Calc.: C, 46.4; H, 4.1; N, 7.1%.
IR: w(CꢀO) 1649s, w(CꢀN) 1635sh cm−1. Specific molar
conductivity, Lm=308 ohm−1 cm2 mol−1 (in acetoni-
trile).
Crystal size (mm)
0.40×0.25
×0.30
0.430/1.126
0.660
Minimum, Maximum, absorption correction
Maximum value of (sin q)/u reached in
intensity mesurement (A
Total no. of reflections measured, q range
No. of unique reflections; Rint
No. of observed reflections
Criterion for observed reflections
Weighting scheme
−1
˚
)
14 359, 3–28°
13 725, 0.045
1738
I\3|(I)
1/|2(F)
219
0.086
0.099
0.02
1.342
3.2.7. [{Pd[4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)-
NH2]}2(v-trans-Ph2PCHꢀCHPPh2)][ClO4]2 5a
Yield 68%. Anal. Found: C, 46.6; H, 3.6; N, 7.1.
C46H46N6O10Cl2Pd2P2. Calc.: C, 46.5; H, 3.9; N, 7.1%.
IR: w(CꢀO) 1641s, w(CꢀN) 1585m cm−1. Specific molar
conductivity, Lm=315 ohm−1 cm2 mol−1 (in acetoni-
trile).
Parameters refined
Value of R
Value of wR
Ratio of max. LS shift to e.s.d. (D/|)
Max. Dz in final difference electron density
−3
˚
map (e A
)
Error in an observation of unit weight
13.467

28
J.M. Vila et al. / Journal of Organometallic Chemistry 556 (1998) 21–30
3.2.8. [{Pd[4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)-
NH2]}2(v-Ph2PC(ꢀCH2)PPh2)][ClO4]2 6a
Yield 81%. Anal. Found: C, 46.2; H, 3.8; N, 7.3.
C46H46N6O10Cl2Pd2P2. Calc.: C, 46.5; H, 3.9; N, 7.1%.
IR: w(CꢀO) 1649s, w(CꢀN) 1634sh cm−1. Specific molar
conductivity, Lm=320 ohm−1 cm2 mol−1 (in acetoni-
trile).
3.2.12. [{Pd{3,4-Me2C6H2C(Me)ꢀNN(H)C(ꢀO)-
NH2]}2(v-Ph2P(CH2)2PPh2)][ClO4]2 4b
Yield 89%. Anal. Found: C, 42.8; H, 4.5; N, 6.6.
C48H52N6O10Cl2Pd2P2. Calc.: C, 47.3; H, 4.3; N, 6.9%.
IR: w(CꢀO) 1643m, w(CꢀN) 1630sh cm−1. Specific mo-
lar conductivity, Lm=340 ohm−1 cm2 mol−1 (in ace-
tonitrile).
3.2.13. [{Pd[3,4-Me2C6H2C(Me)ꢀNN(H)C(ꢀO)-
NH2]}2(v-trans-Ph2PCHꢀCHPPh2)][ClO4]2 5b
Yield 76%. Anal. Found: C, 47.7; H, 4.1; N, 6.7.
C48H50N6O10Cl2Pd2P2. Calc.: C, 47.4; H, 4.1; N, 6.9%.
IR: w(CꢀO) 1647m, w(CꢀN) 1628sh cm−1. Specific mo-
lar conductivity, Lm=333 ohm−1 cm2 mol−1 (in ace-
tonitrile).
3.2.9. [{Pd[4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)-
NH2]}2(v-Ph2PCH2PPh2)][ClO4]2 7a
Yield 80%. Anal. Found: C, 45.2; H, 3.7; N, 7.0.
C45H46N6O10Cl2Pd2P2. Calc.: C, 45.9; H, 3.9; N, 7.1%.
IR: w(CꢀO) 1651s, w(CꢀN) 1631sh cm−1. Specific molar
conductivity, Lm=290 ohm−1 cm2 mol−1 (in acetoni-
trile).
3.2.14. [{Pd[3,4-Me2C6H2C(Me)ꢀNN(H)C(ꢀO)-
NH2]}2(v-Ph2PC(ꢀCH2)PPh2)][ClO4]2 6b
Yield 78%. Anal. Found: C, 47.1; H, 4.1; N, 6.8.
C48H50N6O10Cl2Pd2P2. Calc.: C, 47.4; H, 4.1; N, 6.9%.
IR: w(CꢀO) 1647s, w(CꢀN) 1631sh cm−1. Specific molar
conductivity, Lm=300 ohm−1 cm2 mol−1 (in acetoni-
trile).
3.2.10. [{Pd[3,4-Me2C6H2C(Me)ꢀNN(H)C(ꢀO)-
NH2]}2(v-Ph2P(CH2)4PPh2)][ClO4]2 2b
Yield 77%. Anal. Found: C, 48.2; H, 4.5; N, 6.7.
C50H56N6O10Cl2Pd2P2. Calc.: C, 48.2; H, 4.5; N, 6.7%.
IR: w(CꢀO) 1649m, w(CꢀN) 1630sh cm−1. Specific mo-
lar conductivity, Lm=325 ohm−1 cm2 mol−1 (in ace-
tonitrile).
3.2.15. [{Pd[3,4-Me2C6H2C(Me)ꢀNN(H)C(ꢀO)-
NH2]}2(v-Ph2PCH2PPh2)][ClO4]2 7b
3.2.11. [{Pd{3,4-Me2C6H2C(Me)ꢀNN(H)C(ꢀO)-
NH2]}2(v-Ph2P(CH2)3PPh2)][ClO4]2 3b
Yield 62%. Anal. Found: C, 46.9; H, 4.0; N, 7.1.
C47H50N6O10Cl2Pd2P2. Calc.: C, 46.9; H, 4.2; N, 7.0%.
IR: w(CꢀO) 1660s, w(CꢀN) 1643s cm−1. Specific molar
conductivity, Lm=342 ohm−1 cm2 mol−1 (in acetoni-
trile).
Yield 85%. Anal. Found: C, 47.6; H, 4.3; N, 6.7.
C49H54N6O10Cl2Pd2P2. Calc.: C, 47.7; H, 4.4; N, 6.8%.
IR: w(CꢀO) 1651s, w(CꢀN) 1630sh cm−1. Specific molar
conductivity, Lm=310 ohm−1 cm2 mol−1 (in acetoni-
trile).
3.2.16. [{Pd[C6H4C(Et)ꢀNN(H)C(ꢀO)-
NH2]}2(v-Ph2P(CH2)4PPh2)][ClO4]2 2c
Yield 77%. Anal. Found: C, 47.5; H, 4.2; N, 6.6.
C48H52N6O10Cl2Pd2P2. Calc.: C, 47.3; H, 4.3; N, 6.9%.
IR: w(CꢀO) 1649m, w(CꢀN) 1631w cm−1. Specific mo-
lar conductivity, Lm=250 ohm−1 cm2 mol−1 (in ace-
tonitrile).
Table 4
˚
Selected bond lengths [A] and angles [°] for 3c
˚
Bond lengths (A)
PdꢁC(1)
PdꢁO
OꢁC(10)
PꢁC(11)
PꢁC(31)
N(2)ꢁC(10)
C(1)ꢁC(2)
2.00(2) PdꢁN(1)
2.15(2) PdꢁP
1.25(3) N(1)ꢁN(2)
1.84(2) PꢁC(21)
1.81(2) N(1)ꢁC(7)
1.35(3) N(3)ꢁC(10)
1.41(3) C(2)ꢁC(7)
1.98(2)
2.246(7)
1.40(3)
1.81(2)
1.29(3)
1.35(4)
1.43(4)
3.2.17. [{Pd[C6H4C(Et)ꢀNN(H)C(ꢀO)-
NH2}(Cl)]}2(v-Ph2P(CH2)3PPh2)][ClO4]2 3c
Yield 69%. Anal. Found: C, 46.8; H, 4.0; N, 7.1.
C47H50N6O10Cl2Pd2P2. Calc.: C, 46.8; H, 4.2; N, 7.0%.
IR: w(CꢀO) 1649s, w(CꢀN) 1631s cm−1. Specific molar
conductivity, Lm=312 ohm−1 cm2 mol−1 (in acetoni-
trile).
Bond angles (°)
PꢁPdꢁO
N1ꢁPdꢁC(1)
99.5(4)
79.6(9)
157.3(7)
120(2)
125(3)
122(2)
116(2)
124(2)
106(2)
106(2)
OꢁPdꢁN(1)
PꢁPdꢁC(1)
PꢁPdꢁN(1)
N(1)ꢁC(7)ꢁC(2)
N(2)ꢁN(1)ꢁC(7)
C(2)ꢁC(7)ꢁC(8)
N(1)ꢁN(2)ꢁC(10)
OꢁC(10)ꢁN(3)
C(11)ꢁPꢁC(31)
PꢁC(31)ꢁC(32)
78.2(7)
103.1(7)
173.1(5)
108(2)
122(3)
126(2)
113(2)
120(2)
104.1(8)
111(2)
OꢁPdꢁC(1)
C(1)ꢁC(2)ꢁC(7)
N(1)ꢁC(7)ꢁC(8)
C(3)ꢁC(2)ꢁC(7)
N(2)ꢁC(10)ꢁN(3)
OꢁC(10)N(2)
C(11)ꢁPꢁC(21)
C(21)ꢁPꢁC(31)
3.2.18. [{Pd[C6H4C(Et)ꢀNN(H)C(ꢀO)-
NH2}(Cl)]}2(v-Ph2P(CH2)2PPh2)][ClO4]2 4c
Yield 85%. Anal. Found: C, 46.3; H, 4.2; N, 6.6.
C46H48N6O10Cl2Pd2P2. Calc.: C, 46.4; H, 4.1; N, 7.1%.
IR: w(CꢀO) 1649m, w(CꢀN) 1646sh cm−1. Specific mo-
lar conductivity, Lm=235 ohm−1 cm2 mol−1 (in ace-
tonitrile).

J.M. Vila et al. / Journal of Organometallic Chemistry 556 (1998) 21–30
29
3.2.19. [{Pd[C6H4C(Et)ꢀNN(H)C(ꢀO)-
An alternative route for the synthesis of 2a was
performed as follows:To a suspension of 8a (50 mg,
0.05 mmol) in acetone (15 cm3) AgClO4 (10 mg, 0.05
mmol) was added. The resulting suspension was
stirred for 4 h and filtered trough Celite to remove
the AgCl. The solvent was removed and the product
recrystallized from dichloromethane/hexane to give
2a. 4a, 2c and 3c could be synthesized following a
similar procedure by reacting 9a, 8c and 9c with Ag-
ClO4, respectively.
NH2}(Cl)]}2(v-trans-Ph2PCHꢀCHꢁPPh2)][ClO4]2 5c
Yield 85%. Anal. Found: C, 46.6; H, 3.9; N, 6.9.
C46H46N6O10Cl2Pd2P2.Calc.: C, 46.5; H, 3.9; N, 7.1%.
IR: w(CꢀO) 1651s, w(CꢀN) 1626sh cm−1. Specific mo-
lar conductivity, Lm=290 ohm−1 cm2 mol−1 (in ace-
tonitrile).
3.2.20. [{Pd[C6H4C(Et)ꢀNN(H)C(ꢀO)-
NH2}(Cl]}2(v-Ph2PC(ꢀCH2)PPh2)][ClO4]2 6c
Yield 85%. Anal. Found: C, 46.7; H, 3.8; N, 7.2.
C46H46N6O10Cl2Pd2P2. Calc.: C, 46.5; H, 3.9; N, 7.1%.
IR: w(CꢀO) 1649s, w(CꢀN) 1626sh cm−1. Specific mo-
lar conductivity, Lm=316 ohm−1 cm2 mol−1 (in ace-
tonitrile).
3.3. Single-crystal diffraction analysis
A
yellow prismatic crystal of [{Pd[C6H4C(Et)ꢀ
NN(H)C(ꢀO)NH2]}2(v-Ph2P(CH2)3PPh2)][ClO4]2 3c
was mounted on a glass fiber and used for data col-
lection. Cell constants and an orientation matrix for
data collection were obtained by least-squares refine-
ment of the diffraction data from 25 reflections in the
3.2.21. [{Pd[C6H4C(Et)ꢀNN(H)C(ꢀO)-
NH2}(Cl)]}2(v-Ph2PCH2PPh2)][ClO4]2 7c
Yield 86%. Anal. Found: C, 45.5; H, 3.8; N, 7.1.
C45H46N6O10Cl2Pd2P2. Calc.: C, 45.9; H, 3.9; N, 7.1%.
IR: w(CꢀO) 1655s, w(CꢀN) 1628m cm−1. Specific mo-
lar conductivity, Lm=284 ohm−1 cm2 mol−1 (in ace-
tonitrile).
range 6.23°BqB13.16° in
a
ENRAF-NONIUS
CAD4 automatic diffractometer [20]. Data were col-
lected at 293 K using Mo–Kh radiation (u=0.70930
˚
A) and the ꢀ/2q scan technique. Data were corrected
for Lorentz and polarization effects. An empirical ab-
sorption correction was made [21]. A summary of the
crystal data, experimental details and refinement re-
sults are listed in Table 2.
3.2.22. [{Pd[4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)-
NH2](Cl)}2(v-Ph2P(CH2)4PPh2)] 8a
Ph2P(CH2)4PPh2 (32 mg, 0.08 mmol) was added to
a suspension of 1a (50 mg, 0.15 mmol) in acetone (15
cm3). The mixture was stirred for 4 h, the resulting
white solid filtered off and dried in air. Yield 90%.
Anal. Found: C, 52.8; H, 4.8; N, 7.8.
C48H52N6O2Cl2Pd2P2. Calc.: C, 52.9; H, 4.8; N, 7.7%.
IR: w(CꢀO) 1720s, w(CꢀN) 1620m, w(PdꢁCl) 285w
cm−1. Compounds 9a, 8c and 9c were obtained fol-
lowing a similar procedure.
The structure was solved by direct methods [22]
which revealed the position of all non-H atoms, and
refined on F by full-matrix least-squares procedure
using anisotropic displacement parameters for all non-
H atoms except the phenyl groups and perchlorate
anions. The H atoms were calculated at idealized po-
sitions and added to the structure factor calculations
˚
as fixed contributions (Biso=5.0 A) but their posi-
tional parameters were not refined. After all shift/
e.s.d. ratios were B0.03, the refinement convereged
to the agreement factors listed in Table 2. Atomic
scattering factors from International Tables for X-ray
crystallography [23]. Molecular graphics from ORTEP
[24].
3.2.23. [{Pd[4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)NH2]-
(Cl)}2(v-Ph2P(CH2)2PPh2)] 9a
Yield 79%. Anal. Found: C, 52.2; H, 4.3; N, 7.7.
C46H48N6O2Cl2Pd2P2. Calc.: C, 52.0; H, 4.5; N, 7.9%.
IR: w(CꢀO) 1720s, w(CꢀN) 1620m, w(PdꢁCl) 265w
cm−1
.
Acknowledgements
3.2.23.1. [{Pd[4-MeC6H3C(Me)ꢀNN(H)C(ꢀO)NH2]-
(Cl)}2(v-Ph2P(CH2)4PPh2)] 8c. Yield 79%. Anal.
Found: C, 53.0; H, 5.0; N, 7.8. C48H52N6O2Cl2Pd2P2.
Calc.: C, 52.9; H, 4.8; N, 7.7%. IR: w(CꢀO) 1712s,
We wish to thank the Xunta de Galicia (Spain)
(Proyecto XUGA20913B96) for financial support and
Johnson Matthey for the generous loan of palladium
salt.
w(CꢀN) 1627s, w(PdꢁCl) 280w cm−1
.
3.2.24. [{Pd[C6H4C(Et)ꢀNN(H)C(ꢀO)NH2]-
(Cl)}2(v-Ph2P(CH2)3PPh2)] 9c
References
Yield 85%. Anal. Found: C, 52.4; H, 4.9; N, 7.7.
C47H50N6O2Cl2Pd2P2. Calc.: C, 52.0; H, 4.7; N, 7.8%.
IR: w(CꢀO) 1710s, w(CꢀN) 1629s, w(PdꢁCl) 280w
[1] I. Omae, in: 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.
cm−1
.

30
J.M. Vila et al. / Journal of Organometallic Chemistry 556 (1998) 21–30
[3] G.R. Newkome, W.E. Puckett, W.K. Gupta, G.E Kiefer, Chem.
Ferna´ndez, A. Ferna´ndez, J.M. Ortigueira, J. Organomet. Chem.
506 (1996) 165.
Rev. 86 (1986) 451.
[4] A.D. Ryabov, Chem. Rev. 90 (1990) 403.
[16] L. Pauling, The Nature of the Chemical Bond, 3rd ed., Cornell
University Press, New York, 1960.
[5] M. Pfeffer, Recl. Trav. Chim. Pyas-Bas 109 (1990) 567.
[6] M. Pfeffer, J.P. Sutter, M.A. Rottevel, A. de Cian, J. Fischer,
Tetrahedron 48 (1992) 2440.
[7] A.D. Ryabov, R. van Eldik, G. Le Borgne, M. Pfeffer,
Organometallics 12 (1993) 1386.
[8] P. Espinet, M.A. Esteruelas, L.A. Oro, J.L. Serrano, E. Sola,
Coord. Chem. Rev. 17 (1992) 215.
[9] A. Bose, C.H. Saha, J. Mol. Catal. 49 (1989) 271.
[10] 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.
532 (1997) 171.
[11] M. Nonoyama, Inorg. Chim. Acta 145 (1988) 53.
[12] P. Ghosh, A. Pramanik, N. Bag, G.K. Lahiri, A. Chakravorty,
J. Organomet. Chem. 454 (1993) 237.
[13] S. Tollari, G. Palmisano, F. Demartin, M. Grassi, S. Magnaghi,
S. Cenini, J. Organomet. Chem. 488 (1995) 79.
[14] (a) M. Nonoyama, Inorg. Nucl. Chem. Lett., 14 (1978) 337. (b)
M. Sugimoto, M. Nonoyama, Inorg. Nucl. Chem. Lett., 15
(1979) 405.
[17] D.D. Perrin, W.L.F. Armarego, D.P. Perrin, Purification of
Laboratory Chemicals, 2nd ed., Pergamon, Oxford, 1983.
[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.
547 (1997) 297.
[19] Vogle’s Textbook of Practical Organic Chemistry, 5th ed., Long-
man Scientific and Technical, 1989, p. 1258.
[20] B.A. Frenz et al., Structure Determination Package, SDP/VAX
V. 2.2 College Station, Texas, US, Enraf-Nonius, Delft, The
Netherlands, 1985.
[21] N. Walker, D. Stuart, Acta Crystallogr. A39 (1983) 158.
[22] G.M. Sheldrick. SHELXS86. A Program for the Solution of
Crystal Structures from X-ray Diffraction Data, University of
Go¨ttigen, Germany, 1986.
[23] International Tables for X-ray Crystallography, vol. IV, Kynoch
Press, Birmingham, 1974.
[24] C.K. Johnson, ORTEP II. Report ORNL-5138. Oak Ridge
National Laboratory, Tennessee, US, 1976.
[15] J.M. Vila, M. Gayoso, M.T. Pereira, M. Lo´pez Torres, J.J.
.