Regioselective activation of CH bonds of naphthyl imines at platinum(II). Crystal structures of [PtMe{1-(2′-ClC6H4CH2NCH)C10H6}PPh3] and [PtMe{2-(2′-ClC6H4CH2NCH)C10H6}PPh3]

Article abstract of DOI:10.1016/S0022-328X(01)01230-X

The reaction of [Pt₂Me₄(μ-SMe₂)₂] with ligands 1-(Me₂NCH₂CH₂NCH)C₁₀H₇ (2a) and 2-(Me₂NCH₂CH₂NCH)C₁₀H₇ (2b) carried out in acetone at room temperature produced compounds [PtMe₂{1-(Me₂NCH₂CH₂NCH)C₁₀H₇}] (3a) and [PtMe₂{1-(Me₂NCH₂CH₂NCH)C₁₀H₇}] (3b), respectively, in which the imines act as bidentate [N,N′] ligands. Cyclometallated [C,N,N′] compounds [PtMe{1-(Me₂NCH₂CH₂NCH)C₁₀H₆}] (4a) and [PtMe{2-(Me₂NCH₂CH₂NCH)C₁₀H₆}] (4b) were obtained by refluxing toluene solutions of compounds 3a or 3b. Reaction of [Pt₂Me₄(μ-SMe₂)₂] with ligands 1-(2′-ClC₆H₄CH₂NCH)C₁₀H₇ (2c) and 2-(2′-ClC₆H₄CH₂NCH)C₁₀H₇ (2d) produced straightforward metallation to yield [PtMe{1-(2′-ClC₆H₄CH₂NCH)C₁₀H₆}SMe₂] (5c) and [PtMe{2-(2′-ClC₆H₄CH₂NCH)C₁₀H₆}SMe₂] (5d) containing a [C,N] ligand. Triphenylphosphine derivatives [PtMe{1-(2′-ClC₆H₄CH₂NCH)C₁₀H₆}PPh₃] (6c) and [PtMe{2-(2′-ClC₆H₄CH₂NCH)C₁₀H₆}PPh₃] (6d) were also prepared. All compounds were characterised by NMR spectroscopies and 6c and 6d were also characterised crystallographically. For both [C,N,N′] and [C,N] systems, the metallation took place regioselectively at β-positions of the naphthyl group.

Full text of DOI:10.1016/S0022-328X(01)01230-X

Journal of Organometallic Chemistry 642 (2002) 171–178
www.elsevier.com/locate/jorganchem
Regioselective activation of CꢀH bonds of naphthyl imines at
platinum(II). Crystal structures of
[PtMe{1-(2%-ClC6H4CH2NCH)C10H6}PPh3] and
[PtMe{2-(2%-ClC6H4CH2NCH)C10H6}PPh3]
Margarita Crespo a,*, Merce` Font-Bard´ıa b, Sonia Pe´rez a, Xavier Solans b
a Departament de Qu´ımica Inorga`nica, Facultat de Qu´ımica, Uni6ersitat de Barcelona, Diagonal 647, E-08028 Barcelona, Spain
b Departament de Cristal.lografia, Mineralogia i Dipo`sits Minerals, Uni6ersitat de Barcelona, Mart´ı i Franque`s s/n, E-08028 Barcelona, Spain
Received 4 July 2001; accepted 3 September 2001
Abstract
The reaction of [Pt2Me4(m-SMe2)2] with ligands 1-(Me2NCH2CH2NCH)C10H7 (2a) and 2-(Me2NCH2CH2NCH)C10H7 (2b)
carried out in acetone at room temperature produced compounds [PtMe2{1-(Me2NCH2CH2NCH)C10H7}] (3a) and [PtMe2{1-
(Me2NCH2CH2NCH)C10H7}] (3b), respectively, in which the imines act as bidentate [N,N%] ligands. Cyclometallated [C,N,N%]
compounds [PtMe{1-(Me2NCH2CH2NCH)C10H6}] (4a) and [PtMe{2-(Me2NCH2CH2NCH)C10H6}] (4b) were obtained by reflux-
ing toluene solutions of compounds 3a or 3b. Reaction of [Pt2Me4(m-SMe2)2] with ligands 1-(2%-ClC6H4CH2NCH)C10H7 (2c) and
2-(2%-ClC6H4CH2NCH)C10H7 (2d) produced straightforward metallation to yield [PtMe{1-(2%-ClC6H4CH2NCH)C10H6}SMe2] (5c)
and [PtMe{2-(2%-ClC6H4CH2NCH)C10H6}SMe2] (5d) containing a [C,N] ligand. Triphenylphosphine derivatives [PtMe{1-(2%-
ClC6H4CH2NCH)C10H6}PPh3] (6c) and [PtMe{2-(2%-ClC6H4CH2NCH)C10H6}PPh3] (6d) were also prepared. All compounds were
characterised by NMR spectroscopies and 6c and 6d were also characterised crystallographically. For both [C,N,N%] and [C,N]
systems, the metallation took place regioselectively at b-positions of the naphthyl group. © 2002 Elsevier Science B.V. All rights
reserved.
Keywords: Platinum; Naphthyl imines; Cyclometallation; Crystal structures
1. Introduction
As shown in Scheme 1, naphthalenes with donor-
bearing substituents at C(1) can be cyclometallated at
the ortho-C(2) or the peri-C(8) positions. Palladium
and platinum compounds cyclometallated at the peri
position have been reported [2] including a bis-cyclo-
platinated compound derived from 1-(dimethy-
lamino)naphthalene [3] and a binuclear dipalladated
compound derived from 1,5-bis(dimethylamino)-
naphthalene [4]. For 1,1%-azonaphthalenes, it has been
Cyclometallated platinum and palladium compounds
have been studied extensively, particularly for benzene
derivatives. Metallation sites other than benzene ring
carbon have been less explored, although fused ring
systems and heterocyclic compounds are attractive for
regioselectivity studies due to the presence of non-
equivalent positions.
Following our studies of imines derived from aro-
matic aldehydes [1], we now report the reactions of
[Pt2Me4(m-SMe2)2] with imines derived from 1- and
2-naphthaldehydes.
* Corresponding author. Tel.: +34-93-4021273; fax: +34-93-
4907725.
E-mail address: margarita.crespo@qi.ub.es (M. Crespo).
Scheme 1. Metallation sites for (a) 1-substituted naphthalenes and (b)
2-substituted naphthalenes.
0022-328X/02/$ - see front matter © 2002 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(01)01230-X

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M. Crespo et al. / Journal of Organometallic Chemistry 642 (2002) 171–178
Scheme 2.
reported that metallation at both C(2) and C(8) yields,
respectively, five- and six-membered metallacycles [5].
However, palladation of (1-naphthyl)ethylamine [6],
N,N-dimethyl-1-(1-naphthyl)ethylamine [7] and imines
derived from 1-naphthaldehyde [8] took place exclu-
sively at the C(2) of the naphthyl to give five-membered
metallacycles, which have been used as resolving agents
for phosphines.
Naphthalenes with donor groups at C(2) could, in
principle, be metallated at two non-equivalent posi-
tions, as shown in Scheme 1. Previous reports indicate
that the preferred metallation site is the less hindered
C(3) position [9].
troscopies, elemental analyses and FAB-mass spectra.
In the 1H-NMR spectra, two distinct resonances appear
in the methyl region, both coupled with 195Pt. The one
at higher field with a larger coupling to 195Pt was
assigned to the methyl trans to the NMe2 moiety. The
coordination of the ligand through both nitrogen atoms
is confirmed by the coupling of both amine and imine
protons to platinum. 13C-NMR and FABMS spectra
were consistent with the structures depicted in Scheme
2. The chemical shifts observed for 195Pt were in the
expected range [10] for a platinum(II) centre bound to
two-carbon and two-nitrogen atoms.
Compound [PtMe2{2-(Me2NCH2CH2NCH)C10H7}]
(3b) in acetone solution at room temperature within 16
h produced the cyclometallated compound [PtMe{2-
(Me2NCH2CH2NCH)C10H6}] (4b) in which the imine
acted as a [C,N,N%] ligand. This process consisted of
intramolecular activation of a CꢀH bond of the aryl
group followed by methane elimination as reported for
analogous systems [1]. In marked contrast, compound
[PtMe2{1-(Me2NCH2CH2NCH)C10H7}] (3a) is stable in
acetone solution at room temperature for several days,
which indicates a lower tendency to cyclometallate.
Cyclometallated compound [PtMe{1-(Me2NCH2-
CH2NCH)C10H6}] (4a) could be obtained by refluxing a
toluene solution of compound 3a for 2 h and this
method could also be used to obtain 4b from 3b.
Compound 4 was characterised by NMR spectro-
scopies, elemental analyses and FABMS. In both cases,
the reaction yielded regioselectively one single isomer as
depicted in Scheme 2. Assignment of the aromatic
regions of 4a and 4b was performed with the aid of
1Hꢀ1H correlation spectroscopy (COSY). All spectral
parameters for compound 4 are in good agreement with
the results obtained for analogous aryl cyclometallated
compounds. The values obtained for l(195Pt) are in
2. Results and discussion
Ligands 1-(Me2NCH2CH2NCH)C10H7 (2a), 2-
(Me2NCH2CH2NCH)C10H7 (2b), 1-(2%-ClC6H4CH2-
NCH)C10H7 (2c) and 2-(2%-ClC6H4CH2NCH)C10H7 (2d)
were prepared from the condensation reactions of the
corresponding aldehyde and N,N-dimethylethylenedi-
amine or 2-chlorobenzylamine carried out in toluene at
room temperature. The resulting imines were character-
1
ised by H- and 13C-NMR spectra.
2.1. Cyclometallation in [C,N,N%] systems
The reactions of [Pt2Me4(m-SMe2)2] (1) with poten-
tially terdentate ligands 1-(Me2NCH2CH2NCH)C10H7
(2a) and 2-(Me2NCH2CH2NCH)C10H7 (2b) carried out
in acetone at room temperature produced compounds
[PtMe2{1-(Me2NCH2CH2NCH)C10H7}]
(3a)
and
[PtMe2{1-(Me2NCH2CH2NCH)C10H7}] (3b), respec-
tively, in which the imines act as bidentate [N,N%]
ligands. Compound 3 was characterised by NMR spec-

M. Crespo et al. / Journal of Organometallic Chemistry 642 (2002) 171–178
173
each case shifted towards higher fields when compared
with the corresponding compound 3, which indicates a
decrease in the electronic density of the platinum centre
upon metallation.
tected when the metallation step is hindered by bulky
groups [13].
In both cases, metallation took place exclusively at
b-positions of the naphthalene to yield regioselectively
the endo-metallacycles depicted in Scheme 4. Forma-
tion of exo-metallacycles was not observed in spite of
the fact that this process could be achieved by activa-
tion of a weaker CꢀCl bond. This result suggests the
reactivity order: CꢀH (endo)\CꢀCl (exo) as reported
previously for phenyl systems [1b,1c]. Even though four
metallation sites are available for ligands 2c and 2d, the
results obtained are analogous in terms of selectivity to
those reported above for the terdentate ligands.
The reactions of compounds 5c and 5d with PPh3
were also carried out and produced cyclometallated
compounds [PtMe{1-(2%-ClC6H4CH2NCH)C10H6}PPh3]
(6c) and [PtMe{2-(2%-ClC6H4CH2NCH)C10H6}PPh3]
(6d), respectively, in which the phosphine replaces the
SMe2 ligand. Even with an excess of phosphine, the
metallacycles are not cleaved, which can be taken as an
indication of the high stability of the formed endo-
metallacycles.
As reported in the literature for analogous systems
[8], the metallation site for 4a is C(2), while for 4b, two
singlets in the aromatic region, assigned to H1 and H4,
confirm that the metallation site is C(3). Therefore, for
both naphthyl systems under study, metallation took
place selectively at b-positions to yield four fused ring
systems containing a five-membered metallacycle. Even
though in both cases, substitution at b-position was
thermodynamically favoured [11], the factors involved
in the regioselectivity of the process were not entirely
the same as for ligands 2a and 2b. In the former case,
the only a-position available for metallation should
lead to a less favoured six-membered metallacycle [12],
while for 2b metallation at C(1) would lead to steric
repulsions between the methyl group and H(8) [9].
2.2. Cyclometallation in [C,N] systems
The reactions of [Pt2Me4(m-SMe2)2] (1) with ligands
1-(2%-ClC6H4CH2NCH)C10H7 (2c) and 2-(2%-ClC6H4-
CH2NCH)C10H7 (2d) were also studied. As depicted in
Scheme 3, four different metallation sites are now avail-
able leading to platinum metallacycles with either an
endo-cyclic (containing the CꢁN group) or an exo-
cyclic structure.
Compounds 5 and 6 were characterised by NMR
spectroscopy and elemental analyses and compound 6
was also characterised crystallographically. All spectral
parameters are in good agreement with the results
obtained for analogous aryl cyclometallated com-
pounds. In particular, J(PꢀPt) values are in the same
range as obtained for [PtMe{2-ClC6H4CH2NCHC6-
H4}PPh3] [14] as expected from the similar trans influ-
ence of naphthyl and phenyl groups. The values ob-
tained for l(195Pt) are shifted towards higher fields as
the ligand covalency increases from N-donor (com-
pound 4) to S-donor (compound 5) to P-donor (com-
pound 6).
The reactions of ligands 2c and 2d with [Pt2Me4(m-
SMe2)2] (1) carried out in acetone at room temperature
produced
cyclometallated
platinum
compounds
[PtMe{1-(2%-ClC6H4CH2NCH)C10H6}SMe2] (5c) and
[PtMe{2-(2%-ClC6H4CH2NCH)C10H6}SMe2] (5d) in
which the imines act as a bidentate [C,N] ligands.
The cyclometallation process, which occurs along
with methane formation, takes place under milder con-
ditions than those reported for ligands 2a and 2b.
Previous results indicate that coordination of the imine
ligand to platinum is a preceding step to the cy-
clometallation process but for imines containing only a
single nitrogen, such intermediates could only be de-
2.3. Crystal structures of compounds 6c and 6d
Suitable crystals were grown from dichloromethane
solutions, which were layered with hexane. The crystal
structures are composed of discrete molecules separated
by van der Waals interactions. Selected bond lengths
Scheme 3. Possible metallation sites for (i) ligands 2c and 2d.

174
M. Crespo et al. / Journal of Organometallic Chemistry 642 (2002) 171–178
Scheme 4.
Table 1
and angles are given in Table 1 (6c) and Table 2 (6d),
and molecular views are shown in Fig. 1 (6c) and Fig.
2 (6d).
,
Selected bond lengths (A) and angles (°) for compound 6c with
estimated S.D.
Both structures show that metallation took place at a
b-position of the naphthyl group to yield a three-fused
[6,6,5] ring system containing a five-membered endo-
metallacycle. The methyl group, trans to the nitrogen
atom, and the triphenylphosphine ligand complete a
tetrahedral distorted planar coordination around the
platinum. The metallacycles are approximately planar;
the largest deviation from the mean plane determined
Bond lengths
PtꢀC(19)
PtꢀN
2.035(4)
2.116(3)
1.293(5)
1.403(6)
1.376(6)
1.404(8)
1.373(11)
1.372(8)
1.451(6)
1.505(6)
PtꢀC(1)
PtꢀP
2.045(4)
2.2818(9)
1.478(6)
1.403(6)
1.393(9)
1.420(6)
1.389(13)
1.410(8)
1.426(7)
NꢀC(11)
NꢀC(12)
C(1)ꢀC(2)
C(3)ꢀC(4)
C(4)ꢀC(5)
C(6)ꢀC(7)
C(8)ꢀC(9)
C(10)ꢀC(11)
C(1)ꢀC(10)
C(2)ꢀC(3)
C(4)ꢀC(9)
C(5)ꢀC(6)
C(7)ꢀC(8)
C(9)ꢀC(10)
C(12)ꢀC(13)
,
by the five atoms is 0.0172 A for C(11) (6c) and 0.0197
,
A for N (6d). In each case, the metallacycle is nearly
Bond angles
C(19)ꢀPtꢀC(1)
C(1)ꢀPtꢀN
C(1)ꢀPtꢀP
coplanar with the mean coordination plane, the dihe-
dral angles being 3.02 (6c) and 2.80° (6d). Bond lengths
and angles lie in the usual range for analogous com-
pounds [1,14,15]. The ‘bite’ angles C(naphthyl)ꢀPtꢀN of
79.18 (6c) and 79.67° (6d) are characteristic of cy-
clometallated platinum(II) compounds [16].
91.27(18)
79.18(16)
176.62(11)
C(19)ꢀPtꢀN
C(19)ꢀPtꢀP
NꢀPtꢀP
169.73(16)
90.86(13)
98.85(10)
Table 2
In conclusion, for both [C,N,N%] and [C,N] systems,
the CꢀH bond at the b-position of the naphthyl group
is activated selectively, even in the presence of a weaker
CꢀCl bond.
,
Selected bond lengths (A) and angles (°) for compound 6d with
estimated S.D.
Bond lengths
PtꢀC(37)
PtꢀN
2.057(4)
2.125(3)
1.275(6)
1.447(5)
1.441(5)
1.416(6)
1.424(6)
1.410(7)
1.398(10)
1.501(6)
PtꢀC(3)
PtꢀP
2.052(4)
2.3015(10)
1.469(5)
1.366(6)
1.370(5)
1.416(6)
1.409(6)
1.371(8)
1.358(8)
NꢀC(1)
NꢀC(12)
C(2)ꢀC(7)
C(3)ꢀC(4)
C(5)ꢀC(11)
C(6)ꢀC(7)
C(8)ꢀC(9)
C(10)ꢀC(11)
3. Experimental
C(1)ꢀC(2)
C(2)ꢀC(3)
C(4)ꢀC(5)
C(5)ꢀC(6)
C(6)ꢀC(8)
C(9)ꢀC(10)
C(12)ꢀC(13)
3.1. General
1H-, 13C-, 31P- and 195Pt-NMR spectra were recorded
by using Varian Gemini 200 (1H, 200 MHz; 13C, 50
MHz), Varian XL300FT (13C, 75.4 MHz), Varian 500
(1H and 1Hꢀ1H COSY, 500 MHz), and Bruker 250
(13C, 62.5 MHz; 31P, 101.2 MHz; 195Pt, 54 MHz) spec-
trometers, and referenced to SiMe4 (1H, 13C), H3PO4
(31P) and H2PtCl6 in D2O (195Pt). l-Values are given in
Bond angles
C(3)ꢀPtꢀC(37)
C(37)ꢀPtꢀN
C(37)ꢀPtꢀP
90.06(18)
169.01(18)
86.40(16)
C(3)ꢀPtꢀN
C(3)ꢀPtꢀP
NꢀPtꢀP
79.67(13)
176.05(10)
103.97(10)

M. Crespo et al. / Journal of Organometallic Chemistry 642 (2002) 171–178
175
Fig. 1. Molecular structure of compound 6c.
ppm and J values in Hz. Microanalyses and mass
spectra (FAB, 3-nitrobenzyl alcohol matrix) were per-
formed by the Serveis Cient´ıfico-Te`cnics de la Universi-
tat de Barcelona.
3.2. Preparation of the compounds
Compound [Pt2Me4(m-SMe2)2] (1) was prepared as
reported [17].
3.2.1. Synthetic procedure for the ligands
Compound 2 was prepared by the reaction of 0.46 g
of N,N-dimethylethylenediamine or 0.74
g of 2-
chlorobenzylamine (5.2×10−3 mol) with an equimolar
amount (0.8 g) of the corresponding naphthaldehyde in
toluene (20 ml). The mixture was stirred for 1 h and
dried over Na2SO4. The solvent was removed in a
rotary evaporator to yield yellow oils (2a) or white
solids (2b, 2c and 2d). 1-(Me2NCH2CH2NCH)C10H7
1
(2a). Yield 0.9 g (76%). H-NMR (200 MHz, CDCl3):
3
l=2.32 [s, Ha]; 2.71 [t, J(HbꢀHc)=7, Hb]; 3.84 [td,
3J(HcꢀHb)=7, Hc]; {7.44–7.56 [m, 3H], 7.81–7.88 [m,
3H], 8.84 [d, J(HꢀH)=8, 1H], aromatics}; 8.92 [s, 1H,
Hd]. 13C-NMR (50 MHz, CDCl3): l=45.90 [s, Ca];
{60.21; 60.77, Cb, Cc}, {124.16 [1C], 125.15 [1C], 125.91
[1C], 126.98 [1C], 128.52 [2C], 130.86 [1C], aromatics};
161.24 [s, Cd]. 2-(Me2NCH2CH2NCH)C10H7 (2b). Yield
Fig. 2. Molecular structure of compound 6d.

176
M. Crespo et al. / Journal of Organometallic Chemistry 642 (2002) 171–178
1
3
0.9 g (76%). H-NMR (200 MHz, CDCl3): l=2.32 [s,
Meb]; 2.72 [t, J(HꢀH)=5, Hd]; 2.85 [s, J(HꢀPt)=21,
3
3
Ha]; 2.68 [t, J(HbꢀHc)=7, Hb]; 3.79 [td, J(HcꢀHb)=
7, Hc]; {7.81–8.00 [m, 6H]; 8.28 [s, 1H], aromatics};
8.43 [s, 1H, Hd]. 13C-NMR (50 MHz, CDCl3): l=45.93
[s, Ca]; {60.03; 60.19, Cn, Cc}, {123.79 [1C], 126.32 [1C],
127.00 [1C], 127.76 [1C], 128.33 [1C], 128.50 [1C],
129.76 [1C], aromatics}; 161.82 [s, Cd]. 1-(2%-
ClC6H4CH2NCH)C10H7 (2c). Yield 1.2 g (82%). 1H-
NMR (200 MHz, CDCl3): l=5.03 [s, Ha]; {7.24 [m,
1H], 7.49–7.64 [m, 5H], 7.87–7.98 [m, 4H], 8.97 [d,
J(HH)=8, 1H], aromatics}; 9.07 [s, Hd]. 13C-NMR (50
MHz, CDCl3): l=62.99 [s, Ca]; {124.26, 125.17,
126.00, 126.86, 127.19, 128.14, 128.57, 129.08, 129.23,
129.63, 131.19, CꢀH aromatics}; {132.75, 133.30,
133.74, 137.07, 140.46, aromatics}; 162.60 [s, Cb]. 2-(2%-
ClC6H4CH2NCH)C10H7 (2d). Yield 1.2 g (82%).1H-
NMR (200 MHz, CDCl3): l=4.97 [s, Ha]; {7.29 [m,
2H], 7.39 [d, J(HH)=2, 1H], 7.46–7.57 [m, 3H], 7.84–
7.93 [m, 3H], 8.01 [s, 1H], 8.06 [d, J(HH)=2, 1H],
aromatics}; 8.57 [s, Hb]. 13C-NMR (50 MHz, CDCl3):
l=61.97 [s, Ca]; {123.75, 126.41, 126.84, 127.15,
127.79, 128.15, 128.43, 128.55, 129.21, 129.64, 130.18,
CꢀH aromatics}; {132.98, 133.32, 133.64, 134.70,
136.95, aromatics}; 162.85 [s, Cb].
Hc]; 4.10 [t, J(HꢀH)=5, He]; {7.52 [m, 2H], 7.80 [m,
2H], 7.95 [d, J(HꢀH)=8, 1H], 8.47 [s, H1], 8.65 [d,
J(HꢀH)=8, 1H], aromatics}; 9.12 [s, 3J(PtꢀH)=45,
Hf]. 13C-NMR (75 MHz, CDCl3): l= −24.77
[J(PtꢀC)=810, Mea]; −18.84 [J(PtꢀC)=832, Meb];
49.51 [Cc]; {65.46, 66.10, Cd, Ce}; {125.18, 126.53,
127.49, 127.55, 128.05, 128.72, 130.80, 131.85, 132.64,
134.74, aromatics}; 161.97 [J(PtꢀC)=20, Cf]. 195Pt-
NMR (54 MHz, CDCl3): l= −3565 [s]. FAB(+)-MS,
m/z: 451 [M], 435 [MꢀMe], 419 [Mꢀ2Me]. Anal.
Found: C, 45.0; H, 5.3; N, 5.7. Calc. for C17H24N2Pt:
C, 45.23; H, 5.36; N, 6.20%.
Compounds 4a and 4b were obtained by refluxing
during 2 h a toluene solution (20 ml) containing 100 mg
of the corresponding compound 3. The solvent was
removed in a rotary evaporator and the red residue was
washed with ether (3×2 ml) to yield red (4a) or orange
(4b) solids, which were dried in vacuum.
3.2.2.3. [PtMe{1-(Me2NCH2CH2NCH)C10H6}] (4a).
1
Yield 75 mg (78%). H-NMR (500 MHz, acetone-d6):
2
3
l=0.96 [s, J(PtꢀH)=79, Mea]; 2.80 [s, J(HꢀPt)=20,
Hb]; {3.23 [t, J(HꢀH)=6], 4.23 [t, J(HꢀH)=6], Hc,
Hd}; {7.11 [t, J(HꢀH)=8], 7.19 [t, J(HꢀH)=8], H6,
H7}; {7.48 [d, J(HꢀH)=8.5, J(HꢀPt)=17], 7.62 [d,
J(HꢀH)=8.5, J(HꢀPt)=59], H3, H4}, {7.57 [d,
J(HꢀH)=8], 7.93 [d, J(HꢀH)=8], H5, H8}; 9.59 [s,
3J(PtꢀH)=64, He]. 13C-NMR (62.5 MHz, CDCl3): l=
−10.91 [J(PtꢀC)=792, Mea]; 48.66 [Cb]; {52.50 [s,
J(CꢀPt)=31], 67.85 [s], Cc, Cd}; {121.24, 122.76,
126.41, 129.14, 131.20 [J(CꢀPt)=68], 132.58
[J(CꢀPt)=89], C3ꢀC8}; {130.34, 133.01, 143.00, 148.05
[J(CꢀPt)=1155], aromatics}; 164.32 [J(PtꢀC)=100,
Ce]. 195Pt-NMR (54 MHz, CDCl3): l= −3590 [s].
FAB(+)-MS, m/z: 435 [M], 419 [MꢀMe]. Anal.
Found: C, 44.7; H, 4.9; N, 5.9. Calc. for C16H20N2Pt:
C, 44.13; H, 4.63; N, 6.43%.
3.2.2. Synthetic procedure for the platinum compounds
Compound 3 was obtained by adding a solution of
90 mg (3.9×10−4 mol) of the corresponding imine in
acetone (10 ml) to a solution of 100 mg (1.74×10−4
mol) of compound [Pt2Me4(m-SMe2)2] (1) in acetone (10
ml). The mixture was stirred for 30 min at room
temperature and allowed to settle. Crystals of 3a were
formed readily while 3b was obtained upon removal of
the acetone in a rotary evaporator. The orange-yellow
solids were washed with ether (3×2 ml) and dried in
vacuum.
3.2.2.1. [PtMe2{1-(Me2NCH2CH2NCH)C10H7}] (3a).
Yield 110 mg (70%). 1H-NMR (200 MHz, CDCl3):
2
2
l= −0.08 [s, J(PtꢀH)=89, Mea]; 0.57 [s, J(PtꢀH)=
3.2.2.4. [PtMe{2-(Me2NCH2CH2NCH)C10H6}] (4b).
84, Meb]; 2.78 [m, Hd]; 2.87 [s, J(HꢀPt)=21, Hc]; 4.22
Yield 80 mg (83%). H-NMR (500 MHz, acetone-d6):
3
1
[t, J(HꢀH)=6, He]; {7.55–7.68 [m, 3H], 7.96–8.09 [m,
3H], 8.80 [d, J(HꢀH)=7, 1H], aromatics}; 9.68 [s,
3J(PtꢀH)=44, Hf]. 13C-NMR (62.5 MHz, CDCl3): l=
−25.02 [J(PtꢀC)=803, Mea]; −18.66 [J(PtꢀC)=828,
Meb]; 49.36 [Cc]; {65.25, 65.81, Cd, Ce}; {122.56, 125.35,
126.16, 126.86, 127.19, 128.96, 131.12, 130.58, 131.45,
133.14, aromatics}; 160.61 [J(PtꢀC)=23, Cf]. 195Pt-
NMR (54 MHz, CDCl3): l= −3437 [s]. FAB(+)-MS,
m/z: 435 [MꢀMe], 419 [Mꢀ2Me]. Anal. Found: C, 44.9;
H, 5.4; N, 6.2. Calc. for C17H24N2Pt: C, 45.23; H, 5.36;
N, 6.20%.
l=0.85 [s, J(PtꢀH)=80, Mea]; 2.80 [s, J(HꢀPt)=21,
Hb]; {3.18 [t, J(HꢀH)=6], 4.19 [t, J(HꢀH)=6], Hc,
Hd}; {7.08 [t, J(HꢀH)=8], 7.20 [t, J(HꢀH)=8], H6,
H7}; {7.49 [d, J(HꢀH)=8], 7.55 [d, J(HꢀH)=8], H5,
H8}, 7.63 [s, H1], 7.67 [s, J(HꢀPt)=7, H4]; 8.90 [s,
3J(PtꢀH)=60, He]. 13C-NMR (75.4 MHz, CDCl3): l=
−12.97 [J(PtꢀC)=793, Mea]; 48.79 [Cb]; {52.30
[J(CꢀPt)=29], 67.75 [s], Cc, Cd}; {123.54, 126.89,
127.13, 128.37 [J(CꢀPt)=38], 128.79, 131.40
[J(CꢀPt)=99], C1, C4ꢀC8}; {130.45, 134.48, 135.97,
151.09, aromatics}; 167.06 [J(PtꢀC)=89, Ce]. 195Pt-
NMR (54 MHz, CDCl3): l= −3880 [s]. FAB(+)-MS,
m/z: 435 [M], 419 [MꢀMe]. Anal. Found: C, 43.7; H,
4.6; N, 6.0. Calc. for C16H20N2Pt: C, 44.13; H, 4.63; N,
6.43%.
2
3
3.2.2.2. [PtMe2{2-(Me2NCH2CH2NCH)C10H7}] (3b).
Yield 120 mg (76%). 1H-NMR (200 MHz, CDCl3):
2
2
l=0.23 [s, J(PtꢀH)=90, Mea]; 0.64 [s, J(PtꢀH)=85,

M. Crespo et al. / Journal of Organometallic Chemistry 642 (2002) 171–178
177
J(HꢀH)=8, 2H], aromatics}; 9.02 [s, 3J(HꢀPt)=54,
Hd]. 195Pt-NMR (54 MHz, acetone-d6): l= −3971 [s].
Anal. Found: C, 45.9; H, 4.1; N, 2.6. Calc. for
C21H22ClNPtS: C, 45.87; H, 4.03; N, 2.55%.
Table 3
Crystallographic and refinement data parameters for compounds 6c
and 6d
Compound 6c Compound 6d
Compounds 6c and 6d were obtained by adding 24
mg (0.9×10−4 mol) of PPh3 to a solution of 50 mg
(0.9×10−4 mol) of the corresponding compound 5 in
acetone (10 ml). The mixture was stirred for 1 h at
room temperature and the acetone was removed in a
rotary evaporator. The yellow solids were washed with
hexane (3×2 ml) and ether (3×2 ml) and dried in
vacuum.
Empirical formula
fw
Temperature (K)
C37H31ClNPPt C37H31ClNPPt
751.14
293(2)
0.71069
751.14
293(2)
0.71069
,
Wavelength (A)
(
(
Crystal system, space
Triclinic, P1
Triclinic, P1
group
,
a (A)
10.1280(10)
12.7320(10)
13.0710(10)
113.58(2)
98.3750(10)
91.36(2)
12.2470(10)
12.5220(10)
12.9140(10)
108.8310(10)
106.3750(10)
110.4720(10)
1572.6(2); 2
1.586
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
3.2.2.7.
[PtMe{1-(2%-ClC6H4CH2NCH)C10H6}PPh3]
1
(6c). Yield 50 mg (72%). H-NMR (200 MHz, acetone-
3
,
V (A ); Z
1522.1(2); 2
1.639
d6): l=0.85 [d, J(PtꢀH)=82, J(PꢀH)=8, Mea]; 4.56
2
3
dCalc (Mg m−3
)
[s, Hc], {7.20 [m, 4H], 7.39 [m, 11H], 7.60 [m, 6H],
Absorption coefficient
(mm−1
F(000)
4.777
4.623
3
7.81–8.11 [m, 4H], aromatics}; 9.60 [s, J(HꢀPt)=58,
)
Hd]. 31P-NMR (101.2 MHz, acetone-d6): l=31.21 [s,
J(PtꢀP)=2164]. 195Pt-NMR (54 MHz, acetone-d6): l=
−4280 [s, J(PtꢀP)=2164]. Anal. Found: C, 58.8; H,
4.2; N, 1.7. Calc. for C37H31ClNPPt: C, 59.16; H, 4.16;
N, 1.86%.
740
740
Reflections
8746/6140
13 280/8116
collected/unique
Data/restraints/
parameters
(Rint=0.0283) (Rint=0.0211)
6140/0/390
8116/0/483
GOF on F2
1.105
1.106
R1 (I\2|(I))
wR2 (all data)
Peak and hole (e A
0.0299
0.0323
0.0826
0.0821
3.2.2.8.
[PtMe{2-(2%-ClC6H4CH2NCH)C10H6}PPh3]
−3
,
)
0.694 and
−0.797
0.679 and
−0.597
1
(6d). Yield 45 mg (65%). H-NMR (200 MHz, acetone-
d6): l=0.81 [d, J(PtꢀH)=84, J(PꢀH)=8, Mea]; 4.48
2
3
[s, Hc], {7.24–7.44 [m, 15H], 7.65–7.77 [m, 8H], 8.03
[m, 2H], aromatics}; 8.65 [s, J(HꢀPt)=52, Hd]. 31P-
3
Compounds 5c and 5d were obtained by adding a
solution of 97 mg (3.5×10−4 mol) of the correspond-
ing imine in acetone (10 ml) to a solution of 100 mg
(1.74×10−4 mol) of compound [Pt2Me4(m-SMe2)2] (1)
in acetone (10 ml). The mixture was stirred for 16 h at
room temperature and allowed to settle. Yellow crystals
of 5d were formed readily while 5c was obtained as an
orange solid upon removal of the acetone in a rotary
evaporator. The products were washed with hexane
(3×2 ml) and dried in vacuum.
NMR (101.2 MHz, acetone-d6): l=31.70 [s, J(PtꢀP)=
2200]. 195Pt-NMR (54 MHz, acetone-d6): l= −4255 [s,
J(PtꢀP)=2222]. Anal. Found: C, 56.5; H, 4.2; N, 1.8.
Calc. for C37H31ClNPPt·2H2O: C, 56.45; H, 4.48; N,
1.78%.
3.3. X-ray structure analysis
3.3.1. Data collection
Prismatic crystals were selected and mounted on an
MAR345 diffractometer with an image plate detector.
Unit cell parameters were determined from automatic
centring of 8859 (6c) or 11 785 (6d) reflections (3°B
qB31°) and refined by least-squares method. Intensi-
ties were collected with graphite monochromatised
Mo–Ka radiation. For 6c, 8746 reflections were mea-
sured in the range 2.88°BqB31.57°, 6140 of which
were non-equivalent by symmetry (Rint=0.028) and
5547 reflections were assumed as observed applying the
condition I\2|(I). For 6d, 13 280 reflections were
measured in the range 2.89°BqB31.58°, 8116 of
which were non-equivalent by symmetry (Rint=0.021)
and 7121 reflections were assumed as observed applying
the condition I\2|(I). Lorentz polarisation and ab-
sorption corrections were made. Further details are
given in Table 3.
3.2.2.5.
[PtMe{1-(2%-ClC6H4CH2NCH)C10H6}SMe2]
1
(5c). Yield 150 mg (78%). H-NMR (200 MHz, ace-
tone-d6): l=1.03 [s, 2J(PtꢀH)=82, Mea]; 2.05 [s,
3J(HꢀPt)=27, Hb]; 5.35 [s, J(PtꢀH)=13, Hc], {7.29–
3
7.50 [m, 6H], 7.76–7.93 [m, 3H], 8.25 [d, J(HꢀH)=8,
1H], aromatics}; 9.82 [s, 3J(HꢀPt)=59, Hd]. 195Pt-
NMR (54 MHz, acetone-d6): l= −3986 [s]. Anal.
Found: C, 44.1; H, 4.1; N, 2.4. Calc. for
C21H22ClNPtS.H2O: C, 44.33; H, 4.25; N, 2.46%.
3.2.2.6.
[PtMe{2-(2%-ClC6H4CH2NCH)C10H6}SMe2]
1
(5d). Yield 150 mg (78%). H-NMR (200 MHz, ace-
tone-d6): l=0.98 [s, 2J(PtꢀH)=83, Mea]; 2.08 [s,
3J(HꢀPt)=27, Hb]; 5.33 [s, J(PtꢀH)=13, Hc], {7.41–
3
7.51 [m, 3H], 7.41–7.51 [m, 3H], 7.76[m, 2H], 8.03 [d,

178
M. Crespo et al. / Journal of Organometallic Chemistry 642 (2002) 171–178
3.3.2. Structure solution and refinement
References
The structures were solved by direct methods, using
SHELXS-97 computer program [18], and refined by the
full-matrix least-squares method, with the SHELXL-97
computer program [18] using 6140 (6c) or 8116 (6d)
reflections (very negative intensities were not assumed).
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2
2 2
The function minimised was SwꢀꢀFoꢀ −ꢀFcꢀ ꢀ , where
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2ꢀFcꢀ )/3. f, f %And f ¦ were taken from the International
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The crystallographic data of compounds 6c and 6d
have been deposited with the Cambridge Crystallo-
graphic Data Centre, CCDC no. 166196 and 166195.
Copies of this information may be obtained free of
charge from The Director, CCDC, 12 Union Road,
Cambridge, CB2 1EZ, UK (Fax: +44-1223-336-033;
e-mail: deposit@ccdc.cam.ac.uk or www: http://
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Acknowledgements
This work was supported by the DGICYT (Ministe-
rio de Educacio´n y Cultura, Spain, BQU2000-0652)
and from the Generalitat de Catalunya (project 1997-
SGR-00174).