Synthesis of complexes of platinum (II) with C,N,N′-terdentate Schiff base donor ligands. Crystal and molecular structure of [Pt{3-Me-4-MeOC6H2C(H)=NCH2CH 2NMe2}(Me)]

Article abstract of DOI:10.1016/S0022-328X(98)00606-8

Treatment of the potentially terdentate ligands C₆R_xH_5-xC(H)=N-CH₂CH ₂NMe₂ [R: a (x=2), 2,4-(MeO)₂; b (x=2), 3,4-(MeO)₂; c (x=2), 3-Me-4-MeO; d (x=3), 2,3,4-(MeO)₃; e (x=2), 4,5-(OCH₂O); f (x=1), 2-NO₂] with [PtMe₂(COD)] gave the platinated compounds [Pt{C₆R_xH_4-xC(H)=NCH₂CH ₂-NMe₂}(Me)] with two fused five-membered rings at platinum. The crystal and molecular structure of [Pt{3-Me-4-MeOC₆H₂C(H)=NCH₂CH ₂NMe₂}(Me)] has been determined by X-ray crystallography. The reactivity of these complexes was tested by the reactions of [Pt{2,4-(MeO)₂C₆H₂C(H)=NCH₂CH ₂NMe₂}-(Me)] with tertiary phosphines and diphosphines. In the latter case, dinuclear and mononuclear platinum complexes were synthesized, with bridging or chelating diphosphine ligands, respectively, depending on the complex/diphosphine molar ratio used. The reaction of the related potentially hexadentate ligand 1,4-[Me₂NCH₂CH₂N=(H)C]₂C ₆H₄ with [PtMe₂(COD)] gave the metallated compound [(Me)Pt{Me₂NCH₂CH₂N=(H)C}C₆H ₂{C(H)=N-CH₂CH₂NMe₂}Pt(Me)] with five fused rings.

Full text of DOI:10.1016/S0022-328X(98)00606-8

Journal of Organometallic Chemistry 566 (1998) 93–101
Synthesis of complexes of platinum (II) with C,N,N%-terdentate Schiff
base donor ligands. Crystal and molecular structure of
[Pt{3-Me-4-MeOC6H2C(H)ꢀNCH2CH2NMe2}(Me)]
Jose´ M. Vila a,*, M. Teresa Pereira a, Juan M. Ortigueira a, Dar´ıo Lata a,
Margarita Lo´pez Torres b, Jesu´s J. Ferna´ndez b, Alberto Ferna´ndez b, Harry Adams c
a Department of Inorganic Chemistry, Uni6ersity of Santiago, E-15706 Santiago de Compostela, Spain
b Departamento de Qu´ımica Fundamental e Industrial, Uni6ersidad de La Corun˜a, 15071 La Corun˜a, Spain
c Department of Chemistry, The Uni6ersity, Sheffield S3 7HF, UK
Received 20 February 1998
Abstract
Treatment of the potentially terdentate ligands C6RxH5−xC(H)ꢀN–CH2CH2NMe2 [R: a (x=2), 2,4-(MeO)2; b (x=2),
3,4-(MeO)2; c (x=2), 3-Me-4-MeO; d (x=3), 2,3,4-(MeO)3; e (x=2), 4,5-(OCH2O); f (x=1), 2-NO2] with [PtMe2(COD)] gave
the platinated compounds [Pt{C6RxH4−xC(H)ꢀNCH2CH2–NMe2}(Me)] with two fused five-membered rings at platinum. The
crystal and molecular structure of [Pt{3-Me-4-MeOC6H2C(H)ꢀNCH2CH2NMe2}(Me)] has been determined by X-ray crystallogra-
phy. The reactivity of these complexes was tested by the reactions of [Pt{2,4-(MeO)2C6H2C(H)ꢀNCH2CH2NMe2}–(Me)] with
tertiary phosphines and diphosphines. In the latter case, dinuclear and mononuclear platinum complexes were synthesized, with
bridging or chelating diphosphine ligands, respectively, depending on the complex/diphosphine molar ratio used. The reaction of
the related potentially hexadentate ligand 1,4-[Me2NCH2CH2Nꢀ(H)C]2C6H4 with [PtMe2(COD)] gave the metallated compound
[(Me)Pt{Me2NCH2CH2Nꢀ(H)C}C6H2{C(H)ꢀN–CH2CH2NMe2}Pt(Me)] with five fused rings. © 1998 Elsevier Science S.A. All
rights reserved.
Keywords: Platnium(II) complexes; Schiff base complexes; Metallated compounds
platinum(II) complexes have been described [8], and
more recently photoluminiscent cyclometallated platin-
um(II) complexes have been prepared [9]. Following
our studies on C,N and C,N,N metallacycles, lately we
have become interested in preparing complexes of plat-
inum with similar ligands [10]. Related cyclometallated
compounds of platinum with halogenated multidentate
C,N,N ligands have been developed by oxidative addi-
tion of C–X bonds or, by orthometallation with loss of
methane [11–14], using the platinum complexes
[Pt2Cl4(SMe2)2] or [Pt2Me4(SMe2)2]; crystal structures of
six-co-ordinate platinum(IV) complexes have also been
reported. This paper gives an account of the prepara-
tion of platinum complexes using [PtMe2(COD)] as the
metallating substrate, which proves to be an excellent
1. Introduction
Transition metal complexes with C,N-bonded or-
ganic ligands have aroused great attention in the past
years [1,2]. Many of these complexes are palladium(II)
compounds, which are found to be very useful in liquid
crystals [3], catalysis [4], and in organic synthesis [5];
recently the term cyclic carbopalladation has been
coined [6]. Although platinum(II) complexes have been
less studied than their palladium(II) counterparts, their
applications are nevertheless important, for example, as
compounds with antitumor activity [7]. Also, photo-
physical and photochemical properties of square-planar
* Corresponding author.
0022-328X/98/$19.00 © 1998 Elsevier Science S.A. All rights reserved.
PII S0022-328X(98)00606-8

94
J.M. Vila et al. / Journal of Organometallic Chemistry 566 (1998) 93–101
Fig. 1. a: 2,4-(MeO)2; b: 3,4-(MeO)2; c: 3-Me-4-MeO; d: 2,3,4-(MeO)3; e: 4,5-(OCH2O); f: 2-NO21: 2,4-(MeO)2; 2: 3,4(MeO)2; 3: 3-Me-4-MeO; 4:
2,3,4-MeO)3; 5: 4,5-(OCH2O); 6: 2-NO2; 7: L=PPh3; 8: L=PMePh2; 9: L=Pet2Ph; 10: L=trans-Ph2PCHꢀCHPPh2; 12: L=Ph2P(CH2)4PPh2;
13: L=Ph2P(CH2)3PPh2; 14: L=Ph2P(CH2)2PPh2.
3
material for the synthesis of cycloplatinated complexes
via C–H activation, giving metallacycles with C,N,N
ligands in good yields; the reactivity of one of these
compounds has been tested against tertiary phosphines
and diphosphines. We also present the crystal structure
of a four-coordinate square-planar platinum(II) com-
plex with a C,N,N ligand: the first double metallation
by platinum of an aryl ring.
with JPtH ca. 60 Hz, while broad deceptively simple
triplets for the N(CH2)2N protons were observed. A
singlet at l 2.78–2.87 ppm was assigned to the NMe2
3
resonance with JPtH 22.5–20.2 Hz; the methyls are
equivalent, with the value of JPtH in the range 20.4–
3
21.5 Hz, consistent with a three-bond coupling [15].
Coupling of the NMe2 and of the HCꢀN protons to
195Pt (Table 1) clearly indicated that both nitrogen
atoms of the ligand were co-ordinated to the metal
atom. The PtMe resonance was at l 1.13–0.84 ppm
with 2JPtH 78.6–77.8. The 13C-NMR spectra showed the
CꢀN (2JPtC ca. 95 Hz), C1 (2JPtC ca. 95 Hz) and C6
resonances were shifted to lower field from those of the
free ligand, confirming that metallation had taken place
[16] (Section 3 and Table 1). The methylene carbon
resonances, ꢀNCH2 and CH2NMe2, were shifted to
lower and higher field, respectively, with the latter being
coupled to 195Pt. In those cases where there are two
potential metallation sites, ligands b, c, and e, the NMR
data clearly shows that the preferred position for meta-
lation is the C6 carbon atom in compounds 2, 3, and 5
2. Results and discussion
2.1. Synthesis of
[Pt{C6RxH4-xC(H)ꢀNCH2CH2NMe2}(Me)]
Treatment of the potentially terdentate ligands
C6RxH5-xC(H)ꢀNCH2CH2NMe2
(a–f)
with
[PtMe2(COD)] in toluene gave the platinated com-
pounds [Pt{C6RxH4-xC(H)ꢀNCH2CH2NMe2}(Me)] (1–
6) (Fig. 1) with two fused five-membered rings at
platinum.
1
[17] (Section 3 and Table 1). Thus, JPtC6 was 1076.5,
1085.3, and 1092.3 Hz, respectively, whilst JPtC2 was
The new compounds were obtained as orange (1–5)
or dark red (6) air-stable solids, which were soluble in
the common organic solvents, and they were character-
ised by elemental analysis,1H and 13C-NMR (except 4)
in CDCl3, and the crystal structure determination of
3
52.5, 25.4, and 42.1 Hz, respectively. It has been re-
cently reported that ligand f did not undergo metalla-
tion when treated with [Pt2Me4(SMe2)2] to give an ortho
metallated Pt(II) square-planar compound [12]; how-
ever, under the reaction conditions used in the present
paper the cycloplatinated complex 6 was obtained,
which was fully characterised (Section 3 and Table 1).
The imine HCꢀN, H3, and H5 proton resonances were
1
complex 3. The H and 13C-NMR spectra were unam-
biguously assigned by comparison with the free ligands.
The 1H-NMR spectra showed the HCꢀN resonance
was shifted to lower a field from the free ligand by
0.1–0.3 ppm (except in 6 where the shift is 0.92 ppm),

J.M. Vila et al. / Journal of Organometallic Chemistry 566 (1998) 93–101
95
Table 1
31Pa and 1H-NMRb datac,d
Com-
31P
Aromatic
Others
pound
1
2
3
4
5
6.79[d, JHH=2.2, 1H, H5, 72.0e] 6.01[d, JHH
=
8.76[s, 1H, HCꢀN, 62.2e], 3.83[s, 3H, MeO],
3.74[s, 3H, MeO], 3.95[br t, N=12.0, 2H,
N(CH2)2N], 3.12[br t, N=12.0, 2H, N(CH2)2N],
2.81[s, 6H, NMe2,20.4e], 0.88[s, 3H, PtMe, 77.8e]
8.42[s, 1H, HCꢀN, 60.3e], 3.92[s, 3H, MeO],
3.80[s, 3H, MeO], 3.99[br t, N=12.1, 2H,
N(CH2)2N], 3.13[br t, N=12.1, 2H, N(CH2)2N],
2.83[s, 6H, NMe2, 20.8e], 0.92[s, 3H, PtMe, 78.4e]
8.36[s, 1H, HCꢀN, 60.1e], 3.86[s, 3H, MeO],
3.93[br t, N=12.1, 2H, N(CH2)2N], 3.11[br t,
N=12.1, 2H, N(CH2)2N], 2.81[s, 6H, NMe2,
20.2e], 2.04[s, 3H, Me], 0.89[s, 3H, PtMe, 78.6e]
8.68[s, 1H, HCꢀN, 61.5e], 3.90[s, 3H, MeO],
3.86[s, 3H, MeO], 3.72[s, 3H, MeO], 3.08[br t,
N=12.0, 2H, N(CH2)2N], 2.78[s, 6H, NMe2,
20.5e], 0.84[s, 3H, PtMe, 78.1e]
2.2, 1H, H3]
7.12[s, 1H, H5, 70.3e] 6.88[s, 1H, H2, 11.0e]
7.07[s, 1H, H5, 71.0e] 7.03[s, 1H, H2, 12.8e]
6.88[s, 1H, H5, 72.8e]
6.95[d, JHH=7.8, 1H, H2, 7.7e] 6.47[d, JHH=7.8, 8.48[s, 1H, HCꢀN, 60.3e], 5.92[s, 2H, O(CH2)O],
1H, H3]
3.96[br t, N=11.9, 2H, N(CH2)2N], 3.15[br t,
N=11.9, 2H, N(CH2)2N], 2.82[s, 6H,
NMe2,22.5e], 1.13[s, 3H, PtMe, 76.8e]
6
7
7.97[dd, JHH=7.8, 1.2, 1H, H5, 64.7e] 7.71[dd,
9.62[s, 1H, HCꢀN, 61.0e], 4.22[br t, N=11.8, 2H,
J
HH=7.8, 1.2, 1H, H3] 7.35[t, JHH=7.8, 1H, H4] N(CH2)2N], 3.23[br t, N=11.8, 2H, N(CH2)2N],
2.87[s, 6H, NMe2, 21.5e], 1.07[s, 3H, PtMe, 77.6e]
8.82[s, 1H, HCꢀN, 58.0e], 3.85[s, 3H, MeO],
3.78[s, 3H, MeO], 3.24[br t, N=6.7, 2H,
N(CH2)2N], 1.84[s, 6H, NMe2], 0.70[d, JPH=7.4,
3H, PtMe, 81.2e]
28.1s (2219)g
9.3s (2157)g
12.3s (2165)g
17.0s (2196)g
7.04[d, JPH=5.1, 1H, H5, 57.0e] 6.13[s,1H, H3]
8
7.02[d, JPH=5.2, 1H, H5, 56.4e] 6.13[s,1H, H3]
7.06[dd, JPH=6.1, 2.0f 1H, H5, 54.4e] 6.09[d,
8.75[s, 1H, HCꢀN, 57.2e], 3.86[s, 3H, MeO],
3.76[s, 3H, MeO], 3.18[br t, N=6.7, 2H,
N(CH2)2N], 1.94[s, 6H, NMe2], 0.78[d, JPH=7.6,
3H, PtMe, 80.2e]
9
8.74[s, 1H, HCꢀN, 56.0e], 3.87[s, 3H, MeO],
3.75[s, 3H, MeO], 3.30[br t, N=7.2, 2H,
N(CH2)2N], 2.01[s, 6H, NMe2], 2.01[s, 6H,
NMe2], 0.93[d, JPH=6.8, 3H, PtMe, 81.2e]
8.75[s, 1H, HCꢀN, 56.6e], 3.88[s, 3H, MeO],
3.77[s, 3H, MeO], 3.20[br t, N=7.0, 2H,
N(CH2)2N], 2.04[br t, N=7.0, 2H, N(CH2)2N],
1.84[s, 6H, NMe2], 1.84[s, 6H, NMe2], 0.82[d,
J
HH=2.0,1H, H3]
10
7.02[dd, JPH=6.1, 2.0f 1H, H5, 55.2e] 6.11[d,
HH=2.0, H, H3]
J
J
PH=7.1, 3H, PtMe, 81.0e]
11
21.7s (2170)g
7.00[dd, JPH=4.0, 1.9f 1H, H5, 56.4e] 6.12[d,
HH=1.9, H, H3]
8.69[s, 1H, HCꢀN, 58.2e], 3.88[s, 3H, MeO],
3.78[s, 3H, MeO], 3.01[br t, N=6.5, 2H,
N(CH2)2N], 1.94[br t, N=6.5, 2H, N(CH2)2N],
1.81[s, 6H, NMe2], 0.74[d, JPH=7.3, 3H, PtMe,
80.0e]
J
12
13
25.6d, 10.6d, (2015)g,
(1927)g, (13.2)h
6.41[d, JPH=6.0, 1H, H5, 62.0e], 5.75[s,1H, H3]
6.29[d, JPH=5.9, 2.0f 1H, H5, 64.4e], 5.82[d,
8.86[s, 1H, HCꢀN]3.62[s, 3H, MeO], 3.52[s, 3H,
MeO], 2.33[s, 6H, NMe2], 0.30[t, JPH=6.5, 3H,
PtMe, 61.6e]
8.94[s, 1H, HCꢀN], 3.64[s, 3H, MeO], 3.46[s, 3H,
MeO], 2.36[s, 6H, NMe2], 2.63[br t, N=7.6, 2H,
N(CH2)2N], 0.34[dd, JPH=7.4, 5.6 3H, PtMe,
69.8e]
4.4d, 2.9d, (1922)g,
(1908)g, (17.3)h
J
HH=2.0, 1H, H3]
14
15
51.5d, 45.8d,
6.50[d, JPH=6.4, 1H, H5, 65.0e], 6.01[s,1H, H3]
8.83[s, 1H, HCꢀN], 3.74[s, 3H, MeO], 3.43[s, 3H,
MeO], 2.16[s, 6H, NMe2], 0.54[t, JPH=7.3, 3H,
PtMe, 71.2e]
(1903)g(3515)(19.4)hg
7.45[s, 2H, H2,5, 62.0e]
8.52[s, 2H, HCꢀN, 60.4e], 3.97[br t, N=11.8, 4H,
N(CH2)2N], 3.12[br t, N=11.8, 4H, N(CH2)2N],
2.82[s, 12H, NMe2, 9.8e], 0.89[s, 6H, PtMe, 74.8e]
a In CDCl3. Measured at 100.6 MHz (ca. 20°C); chemical shifts (l) in ppm (90.1) to high frequency of 85% H3PO4.
b In CDCl3, unless otherwise stated. Measured at 250 MHz (ca. 20°C); chemical shifts (l) in ppm (90.01) to high frequency of SiMe4.
e
c Coupling constants in Hz. ds, singlet; d, doublet; dd, doublet of doublets; t, triplet; br, broad. JPtH
.
f JHH.g JPtP.h JPP
.

96
J.M. Vila et al. / Journal of Organometallic Chemistry 566 (1998) 93–101
Table 2
Crystal data for compound 3
shifted to lower field from the free ligand, owing to the
presence of the strong electron-withdrawing –NO2
group.
Formula
C14H22N2OPt
429.43
293(2)
Formula weight
Temperature (K)
Wavelength (A)
2.2. Molecular Structure of Complex 3
˚
0.71073
Crystal color
Orange
The crystal structure has been determined (Fig. 2)
and confirms the geometry predicted from spectro-
scopic studies. Crystallographic data and bond lengths
and angles are listed in Tables 2 and 3, respectively.
The crystal structure consists of discrete molecules
separated by van der Waals distances. The platinum
atom is bonded in a slightly distorted square planar
co-ordination to the ortho carbon of the phenyl ring, to
the carbon atom of the methyl group, and to the iminic
and amine nitrogen atoms. The nitrogen atoms adopt a
cis arrangement. The deviations from the mean plane
(plane 1) are as follows: Pt −0.0165, C(9) 0.0481, N(2)
Crystal size(mm)
Crystal system
Space group
0.65×0.41×0.28
Orthorombic
P212121
˚
Unit cell dimensions
a(A)=7.389(2)
˚
b(A)=11.066(3)
˚
c(A)=18.522(3)
h(°)=90°
i(°)=90°
k(°)=90°
1514.5(6)
4
Volume (Mg m−3
Z
)
Dcalc. Mg m−3
1.883
9.256
Absorption coefficient
(mm−1
F(000)
)
˚
−0.0454, N(1) 0.0433 A. The angles between adjacent
824
atoms in the co-ordination sphere are close to the
expected value of 90°, in the range 99.4(7) to 80.0(7)°,
with the distortions being most noticable in the triden-
tate ligand. The angles C(9)–Pt–N(12), 80.0(7)°, and
N(1)–Pt–N(2), 82.4(6)° are less than 90° and the angles
C(9)–Pt–C(12), 99.4(7)°, and C(12)–Pt–N(1), 98.3(6)°,
are thus \90°. All bond distances are within the
expected range, with allowance for the strong trans
influence of the carbon donor ligands. The Pt–C(9)
q range (°)
Index ranges
Reflections collected
Independent reflections
Absorption correction
Refinement method
2.14–25.00
−1Bh B8, −1BkB13, −1BlB22
2099
1938 (Rint=0.0372)
None
Full-matrix-block least suares on F2
Data/restraints/parameters 1938/0/163
GOF on F2
1.045
Final R indices
[I\2.0|(I)]
R indices (all data)
Absolute structure
parameter
R1=0.0467, wR2=0.0840
R1=0.0828, wR2=0.0965
0.02(4)
˚
bond length (1.97(2) A) is similar to the platinum-aryl
carbon bond length found earlier [12,18,19]. The Pt–
−3
˚
˚
Largest diff. peak and hole 0.684 and −0.772 eA
NMe2 bond length of 2.162(14) A is longer than the
˚
imine Pt–N bond length of 2.04(2) A; the former is
expected to be weakened by the trans aryl group which
has a high trans influence, the longer Pt–N bond is also
consistent with the weak ligating ability of tertiary
amines for platinum [12]. The metallacycle Pt, N(2),
C(3), C(4), and C(9) (plane 2) is planar with mean
˚
deviations from the plane in the range 90.0126 A. The
metallated phenyl ring C(4)–C(9) (plane 3, mean devia-
˚
tions 90.0076 A) is also planar. The ring defined by
Pt, N(2), C(2), C(1), and N(1) (plane 4) shows mean
˚
deviations of 90.1207 A, with the largest deviations on
˚
the C1 and C2 atoms, 0.21 and 0.16 A, respectively,
with angles between planes 1–4 as follows: plane 1/
plane 2, 4.4°, plane 1/plane 3, 7.1°, plane 1/plane 4,
13.6°, plane 2/plane 3, 2.6°, plane 2/plane 4, 9.2°, plane
3/plane 4, 6.5°.
2.3. Synthesis of [Pt{2,4-(MeO)2C6H2C(H)ꢀNCH2CH2
NMe2}(L)(Me)] (L=Phosphine)
The reaction of [Pt{2,4-(MeO)2C6H2C(H)ꢀNCH2
CH2NMe2}–(Me)] with tertiary phosphines gave the
mononuclear complexes [Pt{2,4-(MeO)2C6H2C(H)ꢀN-
CH2CH2NMe2}(L)(Me)] (L=PPh3 (7), PMePh2 (8),
PEt2Ph (9), respectively, as air-stable solids, soluble in
the common organic solvents, which were fully charac-
terised (Section 3 and Table 1). Coupling of the H5
Fig. 2. Molecular structure of complex 3.

J.M. Vila et al. / Journal of Organometallic Chemistry 566 (1998) 93–101
97
resonance to the 31P nucleus was observed in the range
5.1–6.1 ppm, but not of the HCꢀN and ꢀNCH2 reso-
nances. The NMe2 resonance was shifted to higher field
from its value in the free ligand (cf. l NMe2 in a, 2.29
ppm, and in 1, 1.84 ppm) probably due to shielding of
a phosphine phenyl ring. However, no similar shielding
effect was observed at the C(4)-methoxy group as
would be expected from a trans N–Pt–P geometry [20].
Futhermore, no significant high-field shift of the aro-
matic protons of the phenyl ring was observed, as
expected for a cis arrangement of the phosphine and
the metallated ring [21]. These findings are in accor-
dance with a trans C–Pt–P geometry. The complexes
showed singlet resonances in the 31P{1H} NMR spec-
tra, with satellites due to 195Pt, and the value of JPtP in
the range 2218.8–2165.2 Hz is consistent with a
phoshorus trans to a phenyl carbon atom [15].
(10), L=trans-Ph2PCHꢀCHPPh2 (11), respectively, as
air-stable solids, soluble in the common organic sol-
vents, which were fully characterised (Section 3 and
1
Table 1). The H-NMR spectra of the compounds have
been fully assigned. Detailed analysis of the proton
1
resonances in the H-NMR spectra, and of the value of
JPtP, showed that the phosphorus nuclei were in a
trans-C–Pt–P geometry (vide supra). There was only
one set of resonances for each cycloplatinated moiety in
1
the H-NMR spectra and only one singlet for the two
31P nuclei in the 31P{1H}-NMR spectra, which suggests
the compounds to be centrosymmetric, as we have
shown before in related compounds [22]. In the 1H-
NMR spectrum of 11 the expected deceptively simple
triplet of the PCHꢀCHP resonances (AA%XX% spin
system) was occluded by the phosphine resonances.
2.5. Synthesis of [Pt{2,4-(MeO)2C6H2C(H)ꢀNCH2CH2
NMe2}(Me)(L–P,P)] (L=Diphosphine)
2.4. Synthesis of [{Pt[2,4-(MeO)2C6H2C(H)ꢀNCH2
CH2NMe2](Me)}2(v-L)] (L=Diphosphine)
The reaction of [Pt{2,4-(MeO)2C6H2C(H)ꢀNCH2–
CH2NMe2}(Me)] with tertiary diphosphines, in a 1:1
molar ratio, in acetone at r.t. gave the mononuclear
complexes [Pt{2,4-(MeO)2C6H2C(H)ꢀNCH2CH2NMe2}
The reaction of [Pt{2,4-(MeO)2C6H2C(H)ꢀNCH2–
CH2NMe2}(Me)] with tertiary diphosphines, in a 2:1
molar ratio, in acetone at room temperature (r.t.) gave
the dinuclear complexes [{Pt[2,4-(MeO)2C6H2C–(H)ꢀ
(Me)(L–P,P)]
(L=Ph2P(CH2)4PPh2
(12),
L=
NCH2CH2NMe2](Me)}2(v-L)]
(L=Ph2P(CH2)4PPh2
Ph2P(CH2)3PPh2 (13), L=Ph2P(CH2)2PPh2 (14), re-
spectively, as air-stable solids, soluble in the common
organic solvents, which were fully characterised (Sec-
tion 3 and Table 1). In these complexes the Pt(PP)Me
moiety may rotate about the Pt–C vector so that the
platinum co-ordination plane should be at 90° to the
metallated phenyl ring, in analogy with related palla-
dium complexes [21]; nevertheless the H5 proton reso-
nance is still coupled to one phosphorus nucleus. The
31P{1H}-NMR spectra showed two doublets for the
two inequivalent phosphorus nuclei; the one at lower
field was assigned to the 31P nucleus trans to the methyl
group, and the one at higher field was assigned to the
31P nucleus trans to the phenyl carbon atom, on the
basis of a higher trans influence of the methyl group
[23] (vide infra). The PtMe resonance was shifted to
higher field when compared to complexes 1–11, and
appeared in the range 0.54–0.30 ppm, due to the
greater trans influence of the phosphorus atom with
respect to the CꢀN nitrogen atom [24]; accordingly
2JPtMe was smaller than the mean value of ca. 80 Hz,
for complexes 1–11 (Table 1). Surprisingly, the l P
chemical shift values for 14 where strongly shifted
to lower field, with one very high JPtP coupling con-
stant, probably due to the change in ring size of the
Table 3
˚
Bond distances (A) and angles (°) for compound 3
˚
Bond distance (A)
Pt(1)–C(9)
Pt(1)–C(12)
N(1)–C(13)
N(1)–C(1)
N(2)–C(2)
O(1)–C(7)
C(3)–C(4)
C(4)–C(9)
C(6)–C(7)
C(7)–C(8)
1.97(2)
Pt(1)–N(2)
2.04(2)
2.162(14)
1.42(2)
1.30(2)
1.37(3)
1.40(3)
1.38(2)
1.39(2)
1.56(2)
1.39(2)
2.154(13) Pt(1)–N(1)
1.42(3)
1.55(3)
1.45(2)
1.38(2)
1.39(2)
1.42(2)
1.42(2)
1.37(2)
N(1)–C(14)
N(2)–C(3)
O(1)–C(11)
C(1)–C(2)
C(4)–C(5)
C(5)–C(6)
C(6)–C(10)
C(8)–C(9)
Bond angle (°)
C(9)–Pt(1)–N(2)
80.0(7)
C(9)–Pt(1)–C(12)
C(9)–Pt(1)–N(1)
C(12)–Pt(1)–N(1)
99.4(7)
162.0(8)
98.3(6)
N(2)–Pt(1)–C(12) 178.7(5)
N(2)–Pt(1)–N(1) 82.4(6)
C(13)–N(1)–C(14) 112(2)
C(14)–N(1)–C(1) 106(2)
C(14)–N(1)–Pt(1) 115.5(13)
C(3)–N(2)–C(2)
C(2)–N(2)–Pt(1)
C(2)–C(1)–N(1)
N(2)–C(3)–C(4)
C(5)–C(4)–C(9)
C(4)–C(5)–C(6)
C(5)–C(6)–C(10)
C(8)–C(7)–O(1)
O(1)–C(7)–C(6)
C(8)–C(9)–C(4)
C(4)–C(9)–Pt(1)
C(13)–N(1)–C(1) 109(2)
C(13)–N(1)–Pt(1) 109.2(13)
C(1)–N(1)–Pt(1)
C(3)–N(2)–Pt(1)
C(11)–O(1)–C(7) 116(2)
C(1)–C(2)–N(2)
C(5)–C(4)–C(3)
C(3)–C(4)–C(9)
C(5)–C(6)–C(7)
104.8(13)
116.3(13)
130(2)
113.3(13)
114(2)
114(2)
121(2)
123(2)
121(2)
127(2)
113(2)
116(2)
111.9(14)
114(2)
122(2)
118(2)
116(2)
C(7)–C(6)–C(10) 123(2)
chelating diphosphine, that gives
a
stable five-
C(8)–C(7)–C(6)
C(7)–C(8)–C(9)
C(8)–C(9)–Pt(1)
121(2)
123(2)
132(2)
membered ring. Similar strong shifts have been ob-
served before by Canty [25] and co-workers, where the
change in ring size is from a four-membered to a five
membered ring. Garrou [26] has proposed that the

98
J.M. Vila et al. / Journal of Organometallic Chemistry 566 (1998) 93–101
complex is the presence of five fused rings: two sets of
two fused five-membered rings at each platinum center
symmetrically attatched to a six-membered aryl ring.
3. Experimental section
3.1. Materials and instrumentation
All reactions were carried out in an atmosphere of
dry argon. Solvents were purified by standard methods
[28]. Chemicals were reagent grade (1,5-cyclooctadi-
ene)dimethylplatinum(II) was purchased from Alfa
Products. The diphosphines Ph2P(CH2)2PPh2 (dppe),
Ph2P(CH2)3PPh2 (dppp) and Ph2P(CH2)4PPh2 (dppb),
were purchased from Aldrich-Chemie; trans-
Ph2PCHꢀCHPPh2 (trans-1,2-dppe) was prepared ac-
cording to procedures described elsewhere [29].
Microanalyses were carried out at the Servicio de Ana´l-
isis Elemental at the University of Santiago using a
Carlo Erba Elemental Analyser, Model 1108. NMR
spectra were obtained as CDCl3 solutions and refer-
enced to SiMe4 (1H, 13C) or 85% H3PO4 (31P{1H}) and
were recorded on Bruker WM250, AMX-300 and AC-
200 spectrometers. All chemical shifts were reported
downfield from standards.
The synthesis of the Schiff bases 2,4-(Me-
O)2C6H3C(H)ꢀNCH2CH2NMe2 (a), 3,4-(MeO)2C6H3
C(H)ꢀNCH2CH2NMe2 (b), 3-Me-4-MeOC6H3C–(H)ꢀ
NCH2CH2NMe2 (c) 2,3,4-(MeO)3C6H2C(H)ꢀNCH2
CH2NMe2 (d) 4,5-(OCH2O)C6H3C(H)ꢀNCH2CH2N-
Me2 (e) 2-NO2C6H4C(H)ꢀNCH2CH2NMe2 (f) and 1,4-
[Me2NCH2CH2Nꢀ(H)C]2C6H4 (g) was performed by
heating a chloroform solution of the appropriate quan-
tities of 2,4-dimethoxybenzal-dehyde, 3,4-dimethoxy-
benzaldehyde, 3-methyl-4-methoxybenzaldehyde, 2,3,4-
trimethoxybenzaldehyde, piperonal, 2-nitrobenzalde-
hyde or terephtal-aldehyde, respectively, and N,N-
dimethylethylenediamine in a Dean-Stark apparatus
under reflux. The ligands were characterized by their
NMR spectra.
Fig. 3. Synthesis of [(Me)Pt{Me2NCH2CH2Nꢀ(H)C}C6H2{C(H)ꢀN–
CH2CH2Nme2}Pt(Me)] (15).
31P chemical shift is influenced by ring size. The ring
contribution DR was defined as the difference between
the co-ordination shift of a chelated phosphine com-
plex, D (D=Al+B, A and B are constants and l is the
shift for the free ligand), minus the co-ordination shift
of an equivalent phosphorus in a nonchelated analogue.
Each complex was compared to an analogous com-
pound where the phosphorus atom of the chelated
diphosphine was a triphenylphosphine ligand. We have
calcualted [27] DR for compounds 12–14, for both
phosphorus atoms trans to methyl (DR= +2.5, 12;
−18.72, 13; +28.38, 14) and trans to phenyl (DR=
ꢁ13.55, 12; ꢁ21.23, 13; +21.63, 14); compound 14
shows a large positive DR as expected. Also, in the
five-membered ring compound, 14, the absolute value
of DR is smaller when the 31P nucleus is trans to methyl
in comparison to when it is trans to phenyl; the reverse
is true for the six- and seven-membered ring compouds
12 and 13.
2.6. Synthesis of [(Me)Pt{Me2
NCH2CH2Nꢀ(H)C}C6H2{C(H)ꢀN–CH2CH2NMe2}
Pt(Me)] (15)
The reaction of 1,4-[Me2NCH2CH2Nꢀ(H)C]2C6H4
with [PtMe2(COD)] in boiling octane gave the metal-
1
3.2. H-NMR spectra
lated
compound
[(Me)Pt{Me2NCH2CH2Nꢀ(H)C}
C6H2{C(H)ꢀNCH2CH2NMe2}Pt(Me)], 15, which was
fully characterised (Section 3 and Table 1Fig. 3). The
1H-NMR spectrum contains only one set of signals in
accordance with the presence of only one isomer in
solution, i.e. the isomer with the two platinum atoms in
cis positions on the phenyl ring is discarded. There was
a singlet resonance at l 7.45 ppm (2H) assigned to the
H3 and H6 protons, and a singlet resonance at l 8.52
ppm (2H) assigned to the HCꢀN protons. Thus, the
compound is centrosymmetric, and it is the first exam-
ple of a dimetallated platinum(II) complex with a hexa-
dentate organic ligand. A noticeable feature of this
Complex a, 8.62[s, 1H, HCꢀN], 7.86[d, JHH=8.6,
1H, H6], 6.49[dd, JHH=8.6, 2.4, 1H, H5], 6.41[d, JHH
=
2.4, 1H, H3], 3.83[s, 3H, MeO], 3.82[s, 3H, MeO],
3.70[br t, N=14.2, 2H, N(CH2)2N], 2.61[br t, N=14.2,
2H, N(CH2)2N], 2.29[s, 6H, NMe2]; b, 8.22[s, 1H,
HCꢀN], 7.41[d, JHH=1.8, 1H, H2], 7.15[dd, JHH=8.6,
1.8, 1H, H6], 6.87[d, JHH=8.6, 1H, H5], 3.91[s, 3H,
MeO], 3.94[s, 3H, MeO], 3.74[br t, N=14.2, 2H,
N(CH2)2N], 2.63[br t, N=14.2, 2H, N(CH2)2N], 2.31[s,
6H, NMe2]; c, 8.21[s, 1H, HCꢀN], 7.58[d, JHH=2.2,
1H, H2], 7.46[dd, JHH=8.4, 2.2, 1H, H6], 6.82[d, JHH
8.4, 1H, H5], 3.85[s, 3H, MeO], 3.70[br t, N=14.2, 2H,
=

J.M. Vila et al. / Journal of Organometallic Chemistry 566 (1998) 93–101
99
N(CH2)2N], 2.63[br t, N=14.2, 2H, N(CH2)2N], 2.31[s,
6H, NMe2], 2.22[s, 3H, Me]; d, 8.54[s, 1H, HCꢀN],
7.64[d, JHH=8.8, 1H, H6], 6.68[d, JHH=8.8, 1H, H5],
3.90[s, 3H, MeO], 3.86[s, 3H, MeO], 3.85[s, 3H, MeO],
3.70[br t, N=14.1, 2H, N(CH2)2N], 2.60[br t, N=14.1,
2H, N(CH2)2N], 2.28[s, 6H, NMe2]; e, 8.18[s, 1H,
HCꢀN], 7.33[d, JHH=1.6, 1H, H6], 7.09[dd, JHH=8.0,
1.6, 1H, H3], 6.81[d, JHH=8.0, 1H, H2], 5.98[s, 2H,
O(CH2)O], 3.69[br t, N=14.0, 2H, N(CH2)2N], 2.61[br
t, N=14.0, 2H, N(CH2)2N], 2.30[s, 6H, NMe2]; f,
8.70[s, 1H, HCꢀN], 7.76[m, 4H, H3–6], 3.78[br t, N=
13.5, 2H, N(CH2)2N], 2.65[br t, N=13.5, 2H,
N(CH2)2N], 2.29[s, 6H, NMe2]; g, 8.32[s, 2H, HCꢀN],
7.75[s, 4H, H2,3,5,6], 3.74[br t, N=13.8, 4H, N(CH2)2N],
2.64[br t, N=13.8, 4H, N(CH2)2N], 2.29[s, 12H,
NMe2].
N2O2Pt requires: C, 37.7; H, 5.0; N, 6.3. 13C{1H} NMR
data: phenyl, 131.9 (C1, JPtC 39.5), 160.5 (C2, JPtC
70.2), 92.7 (C3),164.4 (C4, JPtC 103.0), 110.3 (C5, JPtC
97.5), 147.6 (C6, JPtC 1162.0). Others, 163.4 (CꢀN, JPtC
98,2), 55.8 (MeO), 55.5 (MeO), 68.6 (N(CH2)2N), 52.1
(N(CH2)2N, JPtC 32.0), 49.1 (NMe2), ꢁ11.6 (PtMe, JPtC
792.3). Compounds 2, 3 and 5 were obtained following
a similar procedure as orange solids.
3.5. Synthesis of [Pt{3,4-(MeO)2C6H2C(H)ꢀNCH2CH2
NMe2}(Me)] (2)
Yield 85%. Anal. Found: C, 37.5; H, 5.3; N, 6.3.
C14H22N2O2Pt requires: C, 37.7; H, 5.0; N, 6.3. 13C{1H}
NMR data: phenyl, 142.5 (C1, JPtC 37.8), 112.4 (C2,
JPtC 52.5), 137.1 (C3),151.7(C4, JPtC 77.0), 116.2 (C5,
JPtC 106.6), 145.0 (C6, JPtC 1076.5). Others, 167.0 (CꢀN,
JPtC 95.2), 56.5 (MeO), 56.1 (MeO), 68.4 (N(CH2)2N),
52.1 (N(CH2)2N, JPtC 30.5), 49.1 (NMe2), ꢁ12.1 (PtMe,
JPtC 794.4).
3.3. 13C{1H} NMR spectra
Complex a, phenyl: 118.0 (C1), 163.1 (C2), 128.5
(C3), 160.1(C4), 105.4 (C5), 90.0 (C6). Others: 157.5
(CꢀN), 60.3 (MeO), 59.8 (MeO), 55.4 (N(CH2)2N), 55.3
(N(CH2)2N), 45.7 (NMe2); b, phenyl: 129.3 (C1), 123.0,
110.3, 108.6 (C2; C5; C6), 151.2, 149.2 (C3; C4). Oth-
ers: 161.4 (CꢀN), 59.5 (MeO), 55.8 (MeO), 60.1
(N(CH2)2N), 59.5 (N(CH2)2N), 45.7 (NMe2); c, phenyl:
126.9, 128.4 (C1; C3), 129.7, 127.8, 109.4 (C2; C5; C6),
159.8 (C4). Others: 161.6 (CꢀN), 55.3 (MeO), 60.1
(N(CH2)2N), 59.6 (N(CH2)2N), 45.7 (NMe2), 16.1 (Me);
d, phenyl: 122.7 (C1), 157.3, 155.7, 141.6 (C2; C3; C4),
122.9, 107.6 (C5; C6). Others: 157.3 (CꢀN), 60.9
(MeO), 60.8 (MeO), 56.0 (MeO), 60.2 (N(CH2)2N), 59.9
(N(CH2)2N), 45.7 (NMe2); e, phenyl: 130.9 (C1), 149.7,
148.1 (C4; C5), 124.3, 107.9, 106.5 (C2; C3; C6). Oth-
ers: 160.9 (CꢀN), 101.3 (OCH2O), 60.1 (N(CH2)2N),
59.4 (N(CH2)2N), 45.7 (NMe2); f, phenyl: 131.0 (C1),
148.6 (C2), 133.3, 130.5, 129.6, 124.1, (C3; C4; C5; C6).
Others: 157.5 (CꢀN), 59.6 (N(CH2)2N), 59.5
(N(CH2)2N), 45.6 (NMe2); g, phenyl: 138.0 (C1, C4),
128.2 (C2, C3, C5, C6). Others: 161.1 (CꢀN), 59.9
(N(CH2)2N), 59.8 (N(CH2)2N), 45.7 (NMe2).
3.6. Synthesis of [Pt{3-Me-4-MeOC6H2C(H)ꢀNCH2
CH2NMe2}(Me)] (3)
Yield 80%. Anal. Found: C, 39.3; H, 5.3; N, 6.3.
C14H22N2OPt requires: C, 39.2; H, 5.2; N, 6.5. 13C{1H}
NMR data: phenyl, 143.2 (C1), 130.9 (C2, JPtC 25.4),
119.7 (C3), 160.4(C4, JPtC 66.3), 115.2 (C5, JPtC 106.0),
143.0 (C6, JPtC 1085.3). Others, 167.1 (C=N, JPtC
96.1), 55.7 (MeO), 68.0 (N(CH2)2N), 51.7 (N(CH2)2N,
JPtC 31.3), 49.0 (NMe2), ꢁ12.3 (PtMe, JPtC 766.9).
Synthesis
of
[Pt{4,5-(OCH2O)C6H2C(H)ꢀNCH2
CH2NMe2}(Me)] (5). Yield 60%. Anal. Found: C, 36.3;
H, 4.4; N 6.7. C13H18N2O2Pt requires: C, 36.4; H, 4.2;
N 6.5. 13C{1H} NMR data: phenyl, 129.4 (C1), 125.3
(C2, JPtC 42.1), 102.7 (C3), 146.8 (C4, JPtC 13.2), 150.4
(C5, JPtC 62.9), 154.1 (C6, JPtC 1092.3). Others, 167.2
(C=N, JPtC 92.9), 100.0 (OCH2O), 68.8 (N(CH2)2N),
52.0 (N(CH2)2N, JPtC 31.9), 49.1 (NMe2), ꢁ19.6 (PtMe,
JPtC 732.9).
Compounds 4 and 6 were obtained following a simi-
lar procedure to that for 1a but the solvent was re-
moved from the final solutions and the products
recrystallised from dichlorometane/hexane to give the
desired complexes as orange and dark-red solids for 4
and 6, respectively. [Pt{2,3,4-(MeO)3C6HC(H)ꢀNCH2
CH2NMe2}(Me)] (4). Yield 80%. Anal. Found: C, 37.8;
H, 5.0; N 5.9. C15H24N2O3Pt requires: C, 37.9; H, 5.1;
N, 5.9. [Pt{2-NO2C6H3C(H)ꢀNCH2CH2NMe2}(Me)]
(6). Yield 70%. Anal. Found: C, 31.9; H, 4.1; N 9.8. C12
H17N3O2Pt requires: C, 31.6; H, 4.1; N, 10.0. 13C{1H}
NMR data: phenyl, 143.5 (C1, JPtC 52.4), 147.8 (C2,
JPtC 42.1) 118.7 (C3), 131.8 (C4, JPtC 79.5), 139.8 (C5,
JPtC 88.9), 146.8 (C6, JPtC 1180). Others, 165.1 (C=N,
JPtC 93.0), 68.3(N(CH2)2N), 53.6 (N(CH2)2N, JPtC 30.8),
49.3 (NMe2), ꢁ10.0 (PtMe, JPtC 795.2).
3.4. Synthesis of [Pt{2,4-(MeO)2C6H2C(H)ꢀNCH2
CH2NMe2}(Me)] (1)
A
pressure tube containing 2,4-(MeO)2C6H3C
(H)ꢀNCH2CH2NMe2 (75 mg, 0.32 mmol), (1,5-cyclooc-
tadiene)dimethylplatinum(II) (100 mg, 0.29 mmol) and
10 cm3 of dry toluene was sealed under argon. The
light-yellow solution was heated at 100°C for 24 h.
After cooling to r.t. the orange solution was filtered
through celite to remove the small amount of black
platinum formed. The solution was concentrated until
an orange crystalline precipitate appeared. The solid
was filtered off and washed with n-hexane. Yield \
95%. Anal. Found, C, 37.6; H, 5.1; N, 6.2. C14H22

100
J.M. Vila et al. / Journal of Organometallic Chemistry 566 (1998) 93–101
3.7. Synthesis of [Pt{2,4(MeO)2C6H2C(H)ꢀNCH2
CH2NMe2}–(PPh3)(Me)] (7)
ethylplatinum(II) (100 mg, 0.29 mmol) were added to
25 cm3 of n-octane to give a pale-yellow solution which
was heated under reflux for 3 h. After cooling to r.t. the
dark-orange precipitate formed was filtered off and
washed with n-hexane. Yield 60%. Anal. Found: C,
31.0; H, 4.4; N, 8.0. C18H30N4Pt2 requires: C, 31.1; H,
4.4; N, 8.1.
A sample of PPh3 (18 mg, 0.068 mmol) was added to
a solution of 1 (30 mg, 0.067 mmol) in acetone (15
cm3). The mixture was stirred for 4 h, the solvent
removed and the product recrystallised from
dichloromethane/hexane to give the desired complex as
an orange solid. Yield 89%. Anal. Found: C, 54.0; H,
5.5; N, 4.1. C32H37N2O2PPt requires: C, 54.3; H, 5.3; N,
4.0. Compounds 8 and 9 were obtained following a
similar procedure as orange solids. [Pt{2,4-
(MeO)2C6H2C(H)ꢀNCH2CH2NMe2}(PMePh2)(Me)]
(8). Yield 77%. Anal. Found: C, 50.4; H, 5.4; N, 4.2.
C27H35N2O2PPt requires: C, 50.2; H, 5.5; N, 4.3.
[Pt{2,4-(MeO)2C6H2C(H)ꢀNCH2CH2NMe2}(PEt2Ph)
(Me)] (9). Yield 86%. Anal. Found: C, 47.2; H, 6.3; N,
4.7. C24H37N2O2PPt requires: C, 47.1; H, 6.1; N, 4.6.
3.11. Single-crystal X-ray diffraction analysis
Three-dimensional, r.t. X-ray data were collected in
the range 3.5B2qB50° on a Siemens P4 diffractome-
ter by the omega scan method. Of the 2099 reflections
measured, all of which were corrected for Lorentz and
polarisation effects (but not for absorption), 1358 inde-
pendent reflections exceeded the significance level ꢀFꢀ/
|(ꢀFꢀ)\4.0. The structure was solved by direct
methods and refined by blocked cascade least squares
on F2. Hydrogen atoms were included in calculated
positions and refined in riding mode. Refinement con-
verged at a final R1=0.0467, (wR2=0.0965 for all 1938
unique data; 163 parameters, mean and maximum l/|
0.000, 0.006), with allowance for thermal anisotropy of
all non-hydrogen atoms. Minimum and maximum final
3.8. Synthesis of [{Pt[2,4-(MeO)2C6H2C(H)ꢀNCH2
CH2NMe2](Me)}2(v-Ph2P(CH2)4PPh2)] (10)
A sample of Ph2P(CH2)4PPh2 (15 mg, 0.035 mmol)
was added to a suspension of 1 (30 mg, 0.67 mmol) in
acetone (15 cm3). The mixture was stirred for 4 h, the
solvent removed and the product recrystallized from
dichloromethane/hexane to give the desired complex as
a yellow solid. Yield 88%. Anal. Found: C, 51.4; H, 5.7;
N, 4.3. C56H72N4O4P2Pt2 requires: C, 51.1; H, 5.5; N,
4.2. Compound 11 was synthesized following a similar
procedure.
electron density −0.772 and 0.684 eA−3. A weighting
˚
scheme w=1/[|2(F02)+(0.0287P)2+1.900P] where
P=(F20+2F2c)/3 was used in the latter stages of refine-
ment. Complex scattering factors were taken from the
program package SHELXL 93 [30] as implemented on
a 486dx computer.
3.9. Synthesis of [{Pt[2,4-(MeO)2C6H2C(H)ꢀNCH2
CH2NMe2](Me)}2(v-trans-Ph2PCHꢀCHPPh2)] (11)
4. Supplementary information
Tables of atomic positional and isotropic displace-
ment parameters, anisotropic displacement parameters,
and hydrogen co-ordinates and isotropic displacement
parameters for the crystal structure of complex 3
availible on request from author.
Yield 92%. Anal. Found: C, 50.3; H, 5.3; N, 4.1.
C54H66N4O4P2Pt2 requires: C, 50.4; H, 5.2; N, 4.3.
Compounds 12, 13 and 14 were obtained following a
similar procedure to that for 10 but using a 1/diphos-
phine 1:1 molar ratio. [Pt{2,4-(MeO)2C6H2C-
(H)ꢀNCH2CH2NMe2}(Me)(Ph2P(CH2)4PPh2–P,
P)]
(12). Yield 85%. Anal. Found: C, 57.7; H, 5.8; N, 3.3.
C42H50N2O2P2Pt requires: C, 57.9; H, 5.8; N, 3.2.
[Pt{2,4 - (MeO)2C6H2C(H)ꢀNCH2CH2NMe2}(Me)(Ph2
P(CH2)3PPh2–P, P)] (13). Yield 87%. Anal. Found: C,
57.2; H, 5.6; N, 3.3. C41H48N2O2P2Pt requires: C, 57.4;
H, 5.6; N, 3.3. [Pt{2,4-(MeO)2C6H2C(H)ꢀNCH2CH2
NMe2}(Me)(Ph2P(CH2)2PPh2-P,P)] (14). Yield 84%.
Anal. Found: C, 57.0; H, 5.5; N, 3.1. C40H46N2O2P2Pt
requires: C, 56.9; H, 5.5; N, 3.3.
Acknowledgements
We thank the Xunta de Galicia (Proyecto
XUGA20913B96) for financial support.
References
[1] S. Trofimenko, Inorg. Chem. 12 (1973) 1215.
[2] (a) I. Omae, Coord. Chem. Rev. 79 1979 287. (b) E.C. Con-
stable, Polyhedron 3 (1984) 1037. (c) I. Omae, Coord. Chem.
Rev. 53 (1984) 261. (d) I. Omae, Organometallic Intramolecular-
coordination Compounds; Elsevier, Amsterdam 1986. (e) V.V.
Dunina, O.A. Zalevskaya, V.M. Potapov, Russ. Chem. Rev. 571
(1984) 250. (f) G.R. Newkome, W.E. Puckett, W.K. Gupta, G.E.
Kiefer, Chem. Rev. 86 (1986) 451.
3.10. Synthesis of [(Me)Pt{Me2NCH2CH2
Nꢀ(H)C}C6H2{C(H)ꢀN–CH2CH2NMe2}Pt(Me)] (15)
A sample of 1,4-[Me2NCH2CH2Nꢀ(H)C]2C6H4 (40
mg, 0.156 mmol) and (1,5-cyclooctadiene)dim-

J.M. Vila et al. / Journal of Organometallic Chemistry 566 (1998) 93–101
101
[3] A. Bose, C.H. Saha, J. Mol. Catal. 49 (1989) 271.
[4] P. Espinet, M.A. Esteruelas, L.A. Oro, J.L. Serrano, E. Sola,
Coord. Chem. Rev. 17 (1992) 215.
[5] (a) A.D. Ryabov, Synthesis 3 (1985) 233. (b) J. Dupont, M.
Pfeffer, J.C. Daran, J. Gouteron, J. Chem. Soc. Dalton. Trans.
(1988) 2421. (c) M. Pfeffer, J.P. Sutter, M.A. Rottevel, A. de
Cian, J. Fischer, Tetrahedron 48 (1992) 2440.
[6] (a) Ma Shengming, Ei-Ichi Negishi, J. Am. Chem. Soc. 117
(1995) 6345. (b) Ei-Ichi Negishi, C. Cope´ret, Ma Shengming,
Liou Show-Yee, Liu Fang, Chem Rev. (1996) 365.
[7] (a) C. Navarro-Ranninger, I. Lo´pez-Solera, V.M. Gonza´lez et
al., Inorg. Chem. 35 (1996) 5181. (b) P. Ramani, R. Ranatunge-
Bandarague, B.H. Robinson, J. Simpson, Organometallics 13
(1994) 500.
[8] (a) M. Maestri, D. Sandrini, V. Balzani, A. von Zelewsky, P.
Jolliet, Helv. Chim. Acta 71 (1988) 134. (b) M. Maestri, Coord.
Chem. Rev. 111 (1991) 117.
[9] T.C. Cheung, K.K. Cheung, S.M. Peng, C.M. Che, J. Chem.
Soc. Dalton Trans. (1996) 1645.
[10] A. Ferna´ndez, Ph. D. Dissertation, University of Santiago, 1995.
[11] G. Minghetti, M.A. Cinellu, S. Stoccoro, A. Zucca, M. Man-
assero, J. Chem. Soc. Dalton Trans. (1996) 777.
[12] C.M. Anderson, M. Crespo, M.C. Jennings, A.J. Lough, G.
Ferguson, R.J. Puddephatt, Organometallics 10 (1991) 2672.
[13] C.M. Anderson, M. Crespo, G. Ferguson, A.J. Lough, R.J.
Puddephatt, Organometallics 11 (1992) 1177.
[17] J.M. Vila, M.T. Pereira, E. Gayoso, M. Gayoso, Transition Met.
Chem. 11 (1986) 342.
[18] (a) C.M. Anderson, R.J. Puddephatt, G. Ferguson, A.J. Lough,
J. Chem. Soc. Chem. Commun. (1989) 1297. (b) C.M. Anderson,
M. Crespo, G. Ferguson, A.J. Lough, R.J. Puddephatt,
Organometallics 11 (1992)1177.
[19] M. Crespo, M. Mart´ınez, J. Sales, X. Sola´ns, M. Font-Bard´ıa,
Organometallics 11 (1992) 1288.
[20] J.M. Vila, M. Gayoso, M.T. Pereira, A. Romar, J.J. Ferna´ndez,
M. Thornton-Pett, J. Organomet. Chem. 401 (1991) 385.
[21] R.M. Ceder, J. Granell, G. Muller, M. Font-Bard´ıa, X. Sola´ns,
Organometallics 14 (1995) 5544.
[22] J.M. Vila, M. Gayoso, A. Ferna´ndez, N.A. Bailey, H. Adams, J.
Organomet. Chem. 448 (1993) 233.
[23] F.A. Cotton, G. Wilkinson, Advanced Inorganic Chemistry, 5th,
Wiley Interscience, New York, 1988, pp. 1299–1300.
[24] P.S. Pregosin, R.W. Kuntz, 31P and 13C-NMR of Transition
Metal Phosphine Complexes, in NMR 16, P. Diehl, E. Fluck, R.
Kosfeld (Eds.), Springer, Berlin, 1979.
[25] A.J. Canty, T Honeyman, J. Organomet. Chem. 387 (1990) 247.
[26] P.E. Garrou, Chem. Rev. 81 (1981) 229.
[27] The data for the co-ordination shift of an equivalent phosphorus
in a nonchelated analogue was taken from M. Crespo, X. Sola´ns,
M. Font-Bard´ıa, Organometallics 14 (1995) 355.
[28] D.D. Perrin, W.L.F. Armarego, Purification of Laboratory
Chemicals 4nd ed., Butterworth-Heinemann 1996.
[14] M. Crespo, Polyhedron 15 (1996) 1981.
[29] W. Hewerston, H.R. Watson, J. Chem. Soc. (1962) 1490.
[30] G.M. Sheldrick, SHELXL 93, An integrated system for solving
and refining structures from diffraction data, University of Go¨t-
tingen, Germany, 1993.
[15] K.K. Hii, S.D. Perera, B.L. Shaw, M.J. Thornton-Pett, J. Chem.
Soc. Dalton Trans. (1994) 103 and references therein.
[16] J. Granell, D. Sa´inz, J. Sales, X. Solans, M.J. Font-Altaba, J.
Chem. Soc. Dalton Trans. (1986) 1785.
.