Synthesis of platinum-iodo-alkyl/aryl complexes in ligand-exchange reactions: Determination of the structure of Pt{(S,S)-bdpp}(X)I complexes (X = Me, I) by X-ray crystallography

Article abstract of DOI:10.1016/j.jorganchem.2006.02.026

Pt{(S,S)-bdpp}(R)I (bdpp = 2,4-bis(diphenylphosphino)pentane; R = Me, Ph, Bz, 2-Tioph) complexes were formed in alkyl/aryl ligand - iodide ligand-exchange reactions by reacting the corresponding Pt{(S,S)-bdpp}R₂ complexes with methyl iodide. Th

Full text of DOI:10.1016/j.jorganchem.2006.02.026

Journal of Organometallic Chemistry 691 (2006) 2846–2852
www.elsevier.com/locate/jorganchem
Synthesis of platinum-iodo-alkyl/aryl complexes in
ligand-exchange reactions: Determination of the structure
of Pt{(S,S)-bdpp}(X)I complexes (X = Me, I) by X-ray crystallography
a
a,b,
c
c,
*
*, Piero Macchi , Angelo Sironi
´
´ ´
´
´
´
Laszlo Janosi , Laszlo Kollar
a
University of Pe´cs, Department of Inorganic Chemistry, H-7624 Pe´cs, Ifju´sa´g, P. O. Box 266, Hungary
Research Group for Chemical Sensors of the Hungarian Academy of Sciences, H-7624 Pe´cs, P.O. Box 266, Hungary
`
Dipartimento di Chimica Strutturale e Stereochimica Inorganica dell’Universita di Milano, Via G. Venezian 21, 20133 Milano, Italy
b
c
Received 27 October 2005; received in revised form 16 February 2006; accepted 20 February 2006
Available online 28 February 2006
Abstract
Pt{(S,S)-bdpp}(R)I (bdpp = 2,4-bis(diphenylphosphino)pentane; R = Me,Ph, Bz, 2-Tioph) complexes were formed in alkyl/aryl
ligand – iodide ligand-exchange reactions by reacting the corresponding Pt{(S,S)-bdpp}R2 complexes with methyl iodide. The
Pt{(S,S)-bdpp}(Me)I complex was isolated and fully characterised. The influence of the X ligand on the platinum-bdpp chelate confor-
mation was investigated in Pt{(S,S)-bdpp}(X)I (X = I, SnCl3, Me) complex series by means of X-ray crystallography.
ꢀ 2006 Elsevier B.V. All rights reserved.
Keywords: Platinum; Iodo-complex; X-ray crystallography; Chelate
1. Introduction
determining role in the stereochemical outcome of the reac-
tion, i.e., platinum-chelate conformation might have a
great impact on the stereochemistry of the alkene insertion.
Moreover, sporadic results are available on the change of
the platinum-chelate conformation by varying the diphos-
phine ligands with catalytic importance [5].
The reactivity of the platinum–alkyl bond towards inser-
tion reactions has been the aim of investigations for a long
time due to its importance in homogeneous catalytic reac-
tions [1]. Among the elementary steps, the insertion of car-
bon monoxide into the platinum–alkyl bond of
a
Due to their high catalytic importance, the synthesis and
structural investigation of Pt(diphosphine)(R)X complexes
is still of direct interest. Prompted by the successful isola-
tion and structural characterisation of Pt(bdpp)I(SnCl3)
[6], we decided to provide a novel methodology for the syn-
thesis of its Pt(bdpp)I(alkyl/aryl) analogues containing this
chiral diphosphine, which is favourably used in various
asymmetric homogeneous catalytic reactions. A new meth-
odology including the application of methyl iodide (and
further iodo-alkenes) has been developed for their synthe-
sis. Furthermore, the structural characterisation of the
above complexes, that could be the key intermediates in
various homogeneous catalytic reactions, might shed some
light on the control of the stereochemistry in enantioselec-
tive homogeneous reactions.
Pt(diphosphine)(alkyl)X (X = halide, SnCl3) complex is a
crucial one in platinum catalysed hydroformylation [2].
The insertion of CO into Pt–carbon bonds has been exten-
sively studied both in case of Pt–alkyl and aryl complexes
containing monodentate phosphine ligands [3]. Although
detailed mechanistic investigations shed some light on the
formation of Pt–acyl complexes from Pt–alkyl complexes
containing diphosphines [4], less are known about the
mechanistic details of the formation of the Pt–alkyl inter-
mediate itself. The importance of this step is due to its
*
Corresponding authors. Tel.: +36 72 327622/4153; fax: +36 72 501527
´
(L. Kollar).
´
E-mail address: kollar@ttk.pte.hu (L. Kollar).
0022-328X/$ - see front matter ꢀ 2006 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2006.02.026

L. Ja´nosi et al. / Journal of Organometallic Chemistry 691 (2006) 2846–2852
2847
2. Results and discussion
MeI
Pt(bdpp)Bz2
→
Pt(bdpp)I2
+
Pt(bdpp)(Me)I + Pt(bdpp)(Bz)I
3a 3c
2.1. Synthesis and NMR characterization of Pt{(S,S)-
bdpp}(R)I and Pt{(S,S)-bdpp}R2 complexes
2c
4
Scheme 2. The reaction of platinum-dibenzyl complex 2c with methyl
iodide.
The synthesis of Pt(diphosphine)(Me)X (X = halide) is a
straightforward one. From the many possibilities, the
alkylation of Pt(diene)X2 with tetramethyltin followed by
the substitution with the corresponding diphosphine is
dominating. A further methodology implies the alkyl/
halide ligand-exchange reactions between Pt(diphos-
phine)X2 and Pt(diphosphine)R2 (R = alkyl) [7].
The diary/dialkyl complexes Pt(1,5-COD)R2 (R = Me
(1a); Ph (1b); Bz (1c); 2-Tioph (1d)), served as starting
materials to ligand exchange investigations, have been syn-
thesised from Pt(1,5-COD)Cl2 (1) [8]. The substitution of
the diene with (S,S)-bdpp resulted in the formation of the
corresponding Pt{(S,S)-bdpp}R2 (2a–2d) complexes in
excellent yields (Scheme 1).
Since the preliminary experiments with 2a have shown
the undesired side reaction of chloride-methyl ligand-
exchange in chloroform (resulting in the formation of
Pt(bdpp)Cl2 and Pt(bdpp)(Me)Cl)) the further reactions
have been carried out in acetonitril.
By reacting 2a with MeI the exclusive formation of 3a
has been observed in a complete reaction within 2 h. The
clean reaction provided 3a as a yellow crystalline material.
The substitution of the ‘second’ methyl ligand for iodide
was failed even in case of 10 molar equivalents of MeI.
Similar behaviour has been observed when n-octyl-iodide
has been used as ‘iodide-source’. However, both methyl
ligands have been substituted by iodo ligands when
CH2I2 was used. The starting complex 2a has been con-
verted completely to Pt(bdpp)I2 (4) [6] which has been iso-
lated as a pale yellow crystalline material. No reaction
occurred in the presence of iodobenzene.
The two diaryl-platinum derivatives, 2b and 2d behaved
similarly to 2a, i.e., monoiodo complexes 3b and 3d were
formed by using MeI. However, the reaction was not com-
plete and the isolation of these two products in high purity
failed. (3b and 3d have been synthesised and isolated by
using independent reaction pathways (see Section 3).) In
the reaction of 2b (or 2d) with CH2I2 (4) was obtained as
major product.
Surprisingly, the reaction of the dibenzyl derivative, 2c
with MeI resulted in a more complicated reaction mixture
(Scheme 2). In addition to the expected benzyl-iodo deriv-
ative 3c and diiodo complex 4, a further monoiodo com-
plex, Pt(bdpp)(Me)I was formed due to the benzyl–
methyl ligand exchange. The reaction of 2c with CH2I2
resulted in the formation of 4 (major product), 3c and
Pt(bdpp)(CH2I)I (3e) (Scheme 3). It has to be noted that
the formation of an additional complex showing a pair of
doublets in 31P NMR has been observed as well, which
can be assigned to a methylene bridging compound
[{Pt(bdpp)I}2(g1,g1-CH2)] (5) (vide infra).
The dialkyl/diaryl complexes 2a–2d showing a single
central line (flanked by platinum satellites) can be easily
identified by 31P NMR spectroscopy (Table 1). The typical
1J(195Pt,31P) coupling constants of diagnostic value falling
in the range of 1700–2000 Hz show the strong trans influ-
ence of the alkyl/aryl group.
The 31P NMR measurements of platinum complexes 3a–
3e provided a sensitive probe for complex structures. The
magnitude of the one-bond interactions, i.e., J(195Pt,31P)
1
coupling constants have been shown to depend strongly
on whether the phosphorus has an aryl/alkyl or iodo ligand
in trans position. The phosphorus trans to iodo ligand pos-
sesses 1J(195Pt,31P) coupling constants larger than 3500 Hz.
However, the phosphorus nuclei trans to alkyl/aryl substi-
tuent have the typical platinum–phosphorus coupling of
1600–2000 Hz similar to those observed in case of dial-
kyl/diaryl complexes 2a–2d.
2.2. Structural characterization of 3a and 4 by X-ray
diffraction
The crystal structures of 3a and 4 share the feature of
having Z0 > 1 (2 and 3, respectively). In the crystals of 3a
there are two independent [Pt{(S,S)-bdpp}(Me)I] mole-
cules in the asymmetric unit (3a-1 and 3a-2) while the crys-
tals of 4 are built from the packing of [Pt{(S,S)-bdpp}I2],
CH2I2 and MeCN molecules, in the 3:1:1 ratio; the three
independent [Pt{(S,S)-bdpp}I2], molecules being labelled
4-1, 4-2 and 4-3. In both cases we do not observe anoma-
lous van der Waals contacts. Fig. 2 report the ORTEP
[9] drawings of the five independent conformers in their
absolute configuration. Relevant bond parameters are
reported in Tables 2 and 3.
CH2I2
Pt(bdpp)Bz2
→
Pt(bdpp)I2 + Pt(bdpp)(Bz)I + Pt(bdpp)(CH2I)I
3c 3e
RSnBu3
bdpp
MeI
2c
4
Pt(1,5-COD)Cl2
→
Pt(1,5-COD)R2
1a-d
→
Pt(bdpp)R2
→
Pt(bdpp)(R)I
+ [{Pt(bdpp)I}2(η1, η1-CH2)]
2a-d
3a/3b/3d
5
Scheme 1. The formation of platinum-iodo-alkyl/aryl complexes in the
reaction of platinum-dialkyl/diaryl complexes with methyl iodide (R = Me
(a); Ph (b); Bz (c); 2-Tioph (d)).
Scheme 3. The reaction of platinum-dibenzyl complex 2c with methylene
iodide.

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L. Ja´nosi et al. / Journal of Organometallic Chemistry 691 (2006) 2846–2852
Table 1
31P NMR data of the platinum–bdpp complexesa
1J(195Pt,31PA) (Hz)
1J(195Pt,31PB) (Hz)
2J(PA,PB) (Hz)
b
b
Complexes
dPA (ppm)
dPB (ppm)
Pt(CH3)2(bdpp) (2a)
Pt(Ph)2(bdpp) (2b)
Pt(Bz)2(bdpp) (2c)
Pt(2-Tioph)2(bdpp) (2d)
PtI(CH3)(bdpp) (3a)
PtI(Ph)(bdpp) (3b)
PtI(Bz)(bdpp) (3c)
PtI(2-Tioph)(bdpp) (3d)
PtI(CH2I)(bdpp) (3e)
PtI2(bdpp) (4)
16.4
13.7
16.7
13.0
11.2
8.2
9.4
9.5
14.7
–
–
–
–
–
1784
1686
1873
1973
1700
1630
1655
1916
1612
–
–
–
–
–
–
–
–
–
23
23
25
24
26
–
8.5
7.9
15.3
8.5
16.3
5.8
8.4
5.4d
4005
3903
4176
3627
4285
3252
ca. 3835e
3278
[{Pt(bdpp)I}2(g1,g1-CH2)] (5)
PtI(SnCl3)(bdpp)f
a
7.0
10.6c
ca. 2826e
2786
20
24
Spectra were measured in acetonitrile with D2O insert (at room temperature).
b
c
d
e
f
PA trans to aryl/alkyl ligand, PB trans to I.
2
2Jtrans
2Jcis
(
31P,117Sn) = 3937 Hz, Jtrans
(
31P,119Sn) = 4105 Hz.
(
31P,117/119Sn) = 157 Hz (117Sn and 119Sn cis-satellites coincide).
The uncertainty in the determination of the coupling constants is due to the overlapping satellites with the central lines of other species (3c, 3e, 4).
See Ref. [6].
Table 2
Selected bond lengths (A) distances and angles (ꢁ) for 4
˚
Mol. A (N = 1, X = 1, Y = 2)
Mol. B (N = 2, X = 3, Y = 4)
Mol. C (N = 3, X = 5, Y = 6)
Pt(N)–P(X)
Pt(N)–P(Y)
Pt(N)–I(X)
Pt(N)–I(Y)
P(X)–C(X11)
P(X)–C(X21)
P(X)–C(N1)
P(Y)–C(Y11)
P(Y)–C(Y21)
P(Y)–C(N3)
C(N1)–C(N2)
C(N1)–C(N4)
C(N2)–C(N3)
C(N3)–C(N5)
P(X)–Pt(N)–P(Y)
I(X)–Pt(N)–I(Y)
2.263(2)
2.250(2)
2.253(2)
2.645(1)
2.670(1)
1.824(6)
1.822(6)
1.851(6)
1.819(6)
1.816(6)
1.851(7)
1.530(10)
1.531(11)
1.514(10)
1.514(11)
91.86(4)
88.06(4)
173.36(4)
171.11(5)
116.5(6)
154.2(6)
14.6(6)
2.247(2)
2.246(2)
2.638(1)
2.649(1)
1.832(7)
1.818(7)
1.854(8)
1.812(6)
1.836(7)
1.825(6)
1.499(12)
1.512(13)
1.567(11)
1.522(10)
92.58(5)
88.63(5)
174.67(5)
173.40(5)
116.2(6)
178.7(6)
3.1(6)
2.237(2)
2.652(1)
2.630(1)
1.804(7)
1.809(6)
1.863(6)
1.811(6)
1.825(6)
1.845(6)
1.518(10)
1.551(10)
1.511(11)
1.514(11)
95.96(4)
87.07(4)
169.88(4)
175.47 (4)
155.2(6)
72.2(6)
P(X)–Pt(N)–I(Y)
P(Y)–Pt(N)–I(X)
Pt(N)–P(X)–C(X11)–C(X12,6)
Pt(N)–P(X)–C(X21)–C(X22,6)
Pt(N)–P(Y)–C(Y11)–C(Y12,6)
Pt(N)–P(Y)–C(Y21)–C(Y22,6)
Pt(N)–P(X)–C(N1)–C(N2)
P(X)–C(N1)–C(N2)–C(N3)
C(N1)–C(N2)–C(N3)–P(Y)
C(N2)–C(N3)–P(Y)–Pt(N)
C(N3)–P(Y)–Pt(N)–P(X)
P(Y)–Pt(N)–P(X)–C(N1)
Pt(N)–P(X)–C(N1)–C(N4)
Pt(N)–P(Y)–C(N3)–C(N5)
53.2(6)
16.7(6)
111.5(6)
ꢀ72.2(5)
24.3(8)
119.5(6)
ꢀ68.3(6)
35.4(9)
ꢀ20.5(7)
56.9(9)
ꢀ82.1(8)
65.1(6)
44.9(8)
34.1(9)
ꢀ61.3(5)
ꢀ66.9(5)
ꢀ29.1(3)
11.2(3)
27.3(3)
10.6(3)
42.2(2)
158.0(5)
169.1(5)
28.1(3)
163.9(7)
167.0(5)
ꢀ148.9(4)
ꢀ62.9(6)
The coordination around the Pt atoms of both
[Pt{(S,S)-bdpp}IMe] and [Pt{(S,S)-bdpp}I2], see Fig. 1, is
square planar with a slight tetrahedral distortion: one P
atom and its trans counterpart (C or, I) being slightly dis-
placed above the Pt coordination plane while the other P
atom (and its trans counterpart) are slightly displaced
below. This feature can also be monitored by the values
of the trans X–Pt–Y angles which significantly differ from
180ꢁ (Tables 2 and 3).
All bond distances fall in the usual range and the only
significant, but expected, intra-molecular effect is the
lengthening of the Pt–P bond trans to the Pt–Me one in
3a. This is also associated to a marginal shortening of the
˚
Pt–P bond trans to the Pt–I one (which average 2.223 A

L. Ja´nosi et al. / Journal of Organometallic Chemistry 691 (2006) 2846–2852
2849
Table 3
˚
Selected bond lengths (A) distances and angles (ꢁ) for 3a
Mol. A (N = 1,
X = 1, Y = 2)
Mol. B (N = 2,
X = 3, Y = 4)
Pt(N)–P(X)
Pt(N)–P(Y)
Pt(N)–I(N)
Pt(N)–C(N)
P(X)–C(X11)
P(X)–C(X21)
P(X)–C(N1)
P(Y)–C(Y11)
P(Y)–C(Y21)
P(Y)–C(N3)
C(N1)–C(N2)
C(N1)–C(N4)
C(N2)–C(N3)
C(N3)–C(N5)
P(X)–Pt(N)–P(Y)
C(N)–Pt(N)–I(N)
2.217(1)
2.323(1)
2.6706(4)
2.222(4)
1.821(5)
1.816(5)
1.856(6)
1.819(4)
1.838(5)
1.867(4)
1.547(7)
1.520(8)
1.541(6)
1.537(7)
95.98(4)
85.91(9)
174.04(4)
171.37(4)
13.7(4)
2.230(1)
2.316(1)
2.6730(5)
2.292(4)
1.823(5)
1.831(5)
1.863(4)
1.822(5)
1.827(4)
1.842(4)
1.533(6)
1.552(7)
1.544(7)
1.534(7)
91.65(4)
84.0(1)
172.4(1)
172.2(1)
124.8(4)
148.5(4)
17.3(4)
106.2(4)
ꢀ74.7(3)
24.3(5)
P(X)–Pt(N)–I(N)
P(Y)–Pt(N)–C(N)
Pt(N)–P(X)–C(X11)–C(X12,6)
Pt(N)–P(X)–C(X21)–C(X22,6)
Pt(N)–P(Y)–C(Y11)–C(Y12,6)
Pt(N)–P(Y)–C(Y21)–C(Y22,6)
Pt(N)–P(X)–C(N1)–C(N2)
P(X)–C(N1)–C(N2)–C(N3)
C(N1)–C(N2)–C(N3)–P(Y)
C(N2)–C(N3)–P(Y)–Pt(N)
C(N3)–P(Y)–Pt(N)–P(X)
P(Y)–Pt(N)–P(X)–C(N1)
Pt(N)–P(X)–C(N1)–C(N4)
Pt(N)–P(Y)–C(N3)–C(N5)
51.6(4)
78.1(4)
154.3(4)
65.2(4)
ꢀ83.2(4)
59.1(5)
46.1(5)
Fig. 1. ORTEP3 drawings of representative molecules of [Pt{(S,S)-
bdpp}I2] (top) and [Pt{(S,S)-bdpp}(Me)I] (bottom). The view is down
to the Pt ‘square planar’ coordination plane. Thermal ellipsoids were
drawn at the 50% probability level. Hydrogen atoms were omitted for
clarity.
ꢀ21.8(4)
10.3(2)
ꢀ28.9(2)
ꢀ64.0(4)
ꢀ151.7(3)
ꢀ61.1(3)
10.3(1)
44.3(2)
156.4(3)
170.7(3)
in 3a while the average of the six independent Pt–I in 4 is
2.249 A).
character and in the face/edge exposure of the phenyl rings.
The bond angles at the Pt atom are also sensitive to the
conformation of the BDPP ligand since the conformations
with an axial methyl group (envelope, twist-chair, chair)
require a larger P–Pt–P ‘bite’ angle [95.96(4)ꢁ and
95.98(4) in molecules 4-1 and 3a-1, respectively] than the
conformations with two equatorial methyls (those close
to d-skew) [92.58(5)ꢁ in 4-3 and 91.86(4)ꢁ and 91.65(4) in
molecules 4-2 and 3a-2, respectively] [9].
In Fig. 3 we report three further conformations (D–F) of
bdpp observed in the known crystal phases of square pla-
nar complexes [M{(S,S)-bdpp}L2]. From the data in
Tables 2 and 3 and a glance on A–F conformers, it is clear
that (i) six-membered metallacycles are rather flexible; (ii)
even if, according to experimental and theoretical data
[10], the skew conformations should be slightly preferred,
the tendency of methyl groups to occupy equatorial posi-
tions can be easily violated; (iii) large variations of the ring
conformations do affect the P–M–P angle hence, particu-
larly in the presence of large substituents, the overall metal
stereochemistry; (iv) the orientation of the phenyl sub-
stituents is not strictly affected by the metallacycle
conformation.
˚
The major stereochemical effects highlighted by this
study concern the shape variability of the bdpp ligand.
Indeed, this ligand, even when bounded to a metal, can
assume many different conformations which, due to the
presence of bulky ring substituents (the phenyls), have lar-
gely different shapes. Thus, we may suppose the presence in
solution of many ‘different’ building blocks which should
favour the occurrence of phenomena like conformational
polymorphism and/or the presence of more than one inde-
pendent molecule in the asymmetric unit. Actually we may
recognise in the two crystal structures three different build-
ing blocks (A, B and C) namely: A with an envelope con-
formation of the metallacycle and one axial, one
equatorial and two bisectional phenyls (molecules 4-1 and
3a-1, which are related by a two-fold rotation about the
P–Pt–P bisector); B with a boat/twist-boat conformation,
one bisectional, one equatorial and two axial phenyls (mol-
ecules 4-2 and 3a-2); and C with delta skew-boat conforma-
tion, two equatorial and two axial phenyls (molecule 4-3)
(Fig. 2).
As previously observed in the Pt(bdpp)I(SnCl3) crystals
[6] when the metallacycle conformation changes substan-
tially, like in the A/C interconversion, there are corre-
spondingly large variations in the axial/equatorial
According to the structure correlation method [10], the
variability of the metallacycle stereochemistry observed in
the solid state should imply a fast solution dynamics. On

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L. Ja´nosi et al. / Journal of Organometallic Chemistry 691 (2006) 2846–2852
Fig. 3. ORTEP3 drawings of different metallacycle conformers, view
along the P–Pt–P bisector, found in the known crystal phases of square
planar complexes [M{(S,S)-bdpp}L2]. (D) [Pd(bdpp)((R)-(Ethoxycarbo-
nylmethineoxy-1,2-phenylene))]; [14] (E) [Pt(pentane-2,4-diyl-bis(5H-dib-
enzo-phosphoindole))Cl2)]; [15] (F) [Pt(bdpp)I(SnCl3)] [6] highlighting the
flexibility of the bdpp ligand.
Fig. 2. ORTEP3 drawings of different metallacycle conformers, view
along the P–Pt–P bisector, found in the crystal phases [Pt{(S,S)-
bdpp}I2] Æ MeCN Æ CH2I2 (4) and [Pt{(S,S)-bdpp}(Me)I] (3a). (A) mole-
cule(s) 4-1 (representative also of 3a-1); (B) molecule(s) 4-2 (representative
also of 3a-2); (C) molecule 4-3. Thermal ellipsoids were drawn at the 50%
probability level. Hydrogen atoms were omitted for clarity.
3. Experimental
3.1. General
The Pt(1,5-COD)Cl2 and Pt(1,5-COD)(Me)2 complexes
as well as tin-derivatives (phenyl-tributyltin, 2-tiophenyl-
tributyltin) were purchased from Aldrich. (S,S)-bdpp was
purchased from Strem. Diarylated complexes (1b and 1d)
were prepared according to a known procedure by reacting
Pt(1,5-COD)Cl2 with PhSnBu3 and (2-Tioph)SnBu3,
respectively [7]. The dibenzyl complex 1c was prepared
from the same precursor by reacting it with BzMgCl Grig-
nard reagent [8].
the other hand, the dynamically averaged molecular config-
urations of [M{(S,S)-bdpp}L2] and [M{(R,R)-bdpp}L2]
must be enantiomeric. Thus, although flexible, this chiral
ancillary ligand is anyway able to control the stereochem-
istry of the alkene insertion but its role is not easily recog-
nizable from just a single structural investigation.

L. Ja´nosi et al. / Journal of Organometallic Chemistry 691 (2006) 2846–2852
2851
Acetonitril was distilled and purified by standard meth-
ods and stored under argon. All reactions were carried out
under argon using standard Schlenk techniques.
was evaporated to dryness and the solid was washed with
cold hexane (3 · 1 ml). The Pt(cod)(Ph)I was obtained as
a grey powder-like material which has to be stored in a
dark ampulle under argon or transferred immediately to
a phosphine complex. Yield: 63%.
50.7 mg (0.1 mmol) Pt(cod)(Ph)I and 41.8 mg (0.095
mmol) (S,S)-bdpp was dissolved in 3 ml of dichlorometh-
ane and was stirred under argon for 14 h. The solvent
was removed in vacuum and the white solid was washed
with hexane and dried in vacuum.
1
The 31P and H NMR spectra were taken on a Varian
Inova 400 spectrometer operating at 400.13 MHz (1H)
and 161.89 MHz (31P). Chemical shifts are reported in
ppm relative to 85% H3PO4 or TMS (downfield) for 31P
1
and H NMR, respectively. Elemental analyses were mea-
sured on a 1108 Carlo Erba apparatus.
3.1.1. Synthesis of Pt{(S,S)-bdpp}(Me)2 (2a) complex
To
Yield: 83%. Anal. Calc. for C35H35P2PtI (839.59): C,
50.07; H, 4.20. Found: C, 50.23; H, 4.36%. For NMR see
Table 1.
a
degassed solution of 66.7 mg (0.2 mmol)
Pt(cod)(Me)2 in 4 ml benzene a degassed solution of
88.1 mg (0.2 mmol) bdpp in 2 ml benzene is added under
argon. The reaction mixture is stirred at room temperature
for 16 h. Half of the solvent was distilled off and a white
precipitate was formed. It was washed with hexane and
dried in vacuum.
Yield: 60%. Anal. Calc. for C31H36P2Pt (665.65): C,
55.92; H, 5.45. Found: C, 56.11; H, 5.67%. For NMR see
Table 1.
3.1.7. Synthesis of Pt{(S,S)-bdpp}(2-Tioph)I (3d) complex
46.9 mg (0.1 mmol) Pt(cod)(2-Tioph)2 and 44.6 mg
(0.08 mmol) Pt(cod)I2 was dissolved in 10 ml dichloro-
methane and stirred for two days at room temperature.
The solvent was evaporated in vacuum and the Pt(cod)(2-
Tioph)I was obtained as dark-yellow material.
51.3 mg (0.1 mmol) Pt(cod)(2-Tioph)I and 41.8 mg
(0.095 mmol) (S,S)-bdpp was dissolved in 3 ml of dichloro-
methane and was stirred under argon for 14 h. The solvent
was removed in vacuum and the yellow solid was washed
with hexane and dried in vacuum.
3.1.2. Synthesis of Pt{(S,S)-bdpp}(Ph)2 (2b) complex
A procedure similar to that described for 2a has been
used.
Yield: 77%. Anal. Calc. for C41H40P2Pt (789.80): C,
62.35; H, 5.10. Found: C, 62.21; H, 5.40%. For NMR see
Table 1.
Yield: 86%. Anal. Calc. for C33H33P2PtIS (845.62): C,
46.87; H, 3.93; S, 3.79. Found: C, 46.91; H, 4.06%. For
NMR see Table 1.
3.1.3. Synthesis of Pt{(S,S)-bdpp}(Bz)2 (2c) complex
A procedure similar to that described for 2a has been
used.
Yield: 58%. Anal. Calc. for C43H44P2Pt (817.85): C,
63.15; H, 5.42. Found: C, 63.30; H, 5.66%. For NMR see
Table 1.
3.1.8. Synthesis of Pt{(S,S)-bdpp}I2 (4) complex
A synthetic procedure for 4 by using the conventional
‘benzonitrile route’ (reacting Pt(PhCN)2I2 with bdpp) has
already been published [6]. An alternative method based
on the ligand exchange reaction of the dimethyl complex
2a can be used as follows.
13.3 mg (0.02 mmol) 2a was suspended in 0.5 ml dry
acetonitrile under argon. 26.8 mg (0.2 mmol) methylene
iodide was added and kept at 80 ꢁC for 2 h. A bright yellow
homogeneous solution was obtained. The highly pure crys-
talline of Pt{(S,S)-bdpp}I2 has been obtained upon cooling
at 4 ꢁC. All the analytical details (NMR, analysis) were
identical with those published earlier for the same com-
pound [6]. Yield: 60%.
3.1.4. Synthesis of Pt{(S,S)-bdpp}(2-Tioph)2 (2d) complex
A procedure similar to that described for 2a has been
used.
Yield: 79%. Anal. Calc. for C37H36P2PtS2 (801.84): C,
55.42; H, 4.53; S, 8.00. Found: C, 55.29; H, 4.65; S,
8.36%. For NMR see Table 1.
3.1.5. Synthesis of Pt{(S,S)-bdpp}(Me)I (3a) complex
13.3 mg (0.02 mmol) 2a was suspended in 0.5 ml aceto-
nitrile and 28.4 mg (0.2 mmol) methyl-iodide was added.
It was stirred at 75 ꢁC for 24 h (until the complex dissolved
completely). The solvent was distilled off until yellow crys-
tals of Pt{(S,S)-bdpp}(Me)I appeared.
Yield: 70%. Anal. Calc. for C30H33P2PtI (777.52): C,
46.34; H, 4.28. Found: C, 46.22; H, 4.39%. For NMR see
Table 1.
3.1.9. X-ray crystal structure determination of [Pt{(S,S)-
bdpp}I2] Æ 1/3MeCN Æ 1/3CH2I2 and of [Pt{(S,S)-
bdpp}(Me)I]
Crystals were mounted on a glass fiber in air and col-
lected at room temperature, on a Bruker APEX CCD
area-detector diffractometer for 4 and a Bruker SMART
CCD for 3a. Crystal data are reported in Table 4. Graph-
˚
ite-monochromatized Mo Ka (k = 0.71073 A) radiation
was used with the generator working at 45 kV and
40 mA. Orientation matrixes were initially obtained from
least-squares refinement on ca. 300 reflections measured
in three different x regions, in the range 0 < h < 23ꢁ; cell
parameters were optimized on the position, determined
3.1.6. Synthesis of Pt{(S,S)-bdpp}(Ph)I (3b) complex
To a solution of 167 mg (0.3 mmol) Pt(cod)I2 in 13 ml
dichloromethane 165.2 mg (0.45 mmol) PhSnBu3 was
added. It was refluxed under argon for 3 days. The solution

2852
L. Ja´nosi et al. / Journal of Organometallic Chemistry 691 (2006) 2846–2852
Table 4
Crystallographic data for the structural analysis has
been deposited with the Cambridge Crystallographic Data
Centre, CCDC No. 287350 for compound 3a and CCDC
No. 287351 for compound 4.
Crystal data and data collection parameters
Identification code
[Pt{(S,S)-bdpp}I2] Æ [Pt{(S,S)-bdpp}-
1/3 MeCN Æ
(Me)I] (3a)
1/3 CH2I2 (4)
Empirical formula
C30H31.67 2.67
I
-
C
30H33IP2Pt
Acknowledgements
N0.33P2Pt
992.32
293(2)
0.71069
P21
Formula weight
Temperature (K)
777.49
293(2)
0.71069
P21
The authors thank the Hungarian Research Fund
(TS044800) for the financial support.
˚
Wavelength (A)
Crystal system,
space group
References
Unit cell dimensions
˚
a (A)
11.316(5)
14.305(5)
29.717(5)
100.381(5)
4732(3)
11.1302(10)
14.5032(13)
18.6585(16)
106.229(2)
2891.9(4)
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˚
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M. Gomez, G. Muller, D. Sainz, J. Sales, Organometallics 10 (1991)
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ꢀ15 6 h 6 15,
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76998/28580
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94.3%
None
Full-matrix
least-squares on F2 least-squares on F2
28580/3/981
1.023
R1 = 0.0371,
wR2 = 0.0796
R1 = 0.0530,
wR2 = 0.0857
ꢀ16 6 h 6 16,
ꢀ21 6 k 6 21,
ꢀ 28 6 l 6 27
52539/19671
[Rint = 0.0286]
94.2%
´
´
´
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T. Kegl, L. Kollar, L. Radics, Inorg. Chim. Acta 265 (1997) 249.
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´
L. Kollar, G. Consiglio, P. Pino, J. Organomet. Chem. 330 (1987)
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´
´
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ꢀ0.001(3)
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´
I. Toth, I. Guo, B. Hanson, Organometallics 12 (1993) 848;
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after integration, of ca. 8000 reflections. The intensity data
were collected within the limits 2h < 62.8ꢁ (4) and
2h < 65.5ꢁ (3a) in the full sphere (x scan method), with
sample-detector distance fixed at 4.72 and 3.86 cm., respec-
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[Rh(BDPP)(COD)]+ [(d-skew) P-Rh–P 88.6(1)ꢁ] J. Bakos, I. Toth,
´
´
´
B. Heil, G. Szalontai, L. Parkanyi, V. Fulo¨p, J. Organomet. Chem.
¨
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