Synthesis, structure and reactivity of new late transition metal complexes bearing diphosphane ligands derived from bis(pyrazol-1-yl)methane

Article abstract of DOI:10.1002/ejic.200300202

Modification of the multistep synthesis of the previously described bis [5-(diphenylphosphanyl)pyrazol-1-yl)]methane (bppzm, 1) produces the novel diphosphane (diphenylphosphanyl)-[5-(diphenylphosphanyl)pyrazol-1-yl](pyrazol-1-yl)-methane (p4m, 2). Treatment of this ligand with [MCl₂-(PhCN)₂] (M = Pd, Pt) or [M(COD)(THF)₂]BF₄ (M = Rh, Ir) produces [MCl₂(p4m)] (M = Pd 3, Pt 4) or [M(COD)(p4m)]BF₄ (M = Rh 5, lr 6) complexes, which chelate in a P,P-bidentate fashion. Sulfidation of bppzm and p4m produces the disulfidophosphanes bppzmS₂ (7) and p4mS₂ (8). Treatment of 7 and 8 with [PdCl₂(PhCN) ₂] produces [PdCl₂(bppzmS₂)] (9) and [PdCl ₂(pmS₂)] (10), respectively, in which ligands 7 and 8 act in an N,N-bidentate chelate fashion. In contrast, ligand 8 reacts with [Rh(COD)(THF)₂]BF₄ to produce [Rh(COD)-(p4mS ₂)]BF₄, where ligand 7 acts in a dynamic S,S-chelate fashion. The activity of some of these complexes in the catalytic hydrogenation of olefins is reported and the single-crystal X-ray structures of 4, 8, and 9 have been obtained. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).

Full text of DOI:10.1002/ejic.200300202

FULL PAPER
Synthesis, Structure and Reactivity of New Late Transition Metal Complexes
Bearing Diphosphane Ligands Derived from Bis(pyrazol-1-yl)methane
[a]
[a]
[b]
[a]
´
Antonio Otero,* Fernando Carrillo-Hermosilla,* Pilar Terreros, Teresa Exposito,
[b]
[a]
[a]
[a]
´
´
˜
Sergio Rojas, Juan Fernandez-Baeza, Antonio Antinolo, and Isabel Lopez-Solera
Keywords: Nitrogen heterocycles / Phosphanes / Palladium / Platinum / Rhodium / Iridium / Hydrogenation
Modification of the multistep synthesis of the previously de-
scribed bis[5-(diphenylphosphanyl)pyrazol-1-yl)]methane
and 8 with [PdCl2(PhCN)2] produces [PdCl2(bppzmS2)] (9)
and [PdCl2(pmS2)] (10), respectively, in which ligands 7 and
8 act in an N,N-bidentate chelate fashion. In contrast, ligand
8 reacts with [Rh(COD)(THF)2]BF4 to produce [Rh(COD)-
(p4mS2)]BF4, where ligand 7 acts in a dynamic S,S-chelate
fashion. The activity of some of these complexes in the cata-
lytic hydrogenation of olefins is reported and the single-crys-
tal X-ray structures of 4, 8, and 9 have been obtained.
( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
(bppzm, 1) produces the novel diphosphane (diphenylphos-
phanyl)-[5-(diphenylphosphanyl)pyrazol-1-yl](pyrazol-1-yl)-
methane (p4m, 2). Treatment of this ligand with [MCl2-
(PhCN)2] (M = Pd, Pt) or [M(COD)(THF)2]BF4 (M = Rh, Ir)
produces [MCl2(p4m)] (M = Pd 3, Pt 4) or [M(COD)(p4m)]BF4
(M = Rh 5, Ir 6) complexes, which chelate in a P,P-bidentate
fashion. Sulfidation of bppzm and p4m produces the disulfi-
dophosphanes bppzmS2 (7) and p4mS2 (8). Treatment of 7 Germany, 2003)
Introduction
metallacycle were found for the late metals (see Figure 1),
confirming the hard-hard, soft-soft acid-base principle.
The synthesis of polydentate phosphanes is a continu-
ously developing field because these ligands are expected to
allow greater control over the coordination sphere of a me-
tal.[1] Increasing interest in the use of polyfunctional ligands
has focused the attention of researchers on phosphanes
with groups bearing nitrogen donors. Phosphorus-nitrogen
hemilabile ligands are particularly useful in catalytic pro-
cesses because one part of the ligand is capable of partially
dissociating from the chelate form, thus allowing a sub-
strate to coordinate to the metal centre and undergo some
transformation.[2] With these precedents in mind, we have
previously prepared and characterized[3] several poly(pyra-
zol-1-yl)methane derivatives bearing phosphane groups on
the pyrazole rings, for example bis[5-(diphenylphosphanyl)-
pyrazol-1-yl]methane (bppzm) (1). The coordinative ca-
pacity of the bppzm ligand was investigated with the metal
centres niobium, palladium and platinum. In the first case,
N,N-six-membered metallacyclic species were isolated.
However, square-planar species with a P,P-eight-membered
Figure 1. Complexes with the bppzm ligand
Research into the related phosphane sulfide ligands has
been much less extensive.[4] Several complexes of late tran-
sition metals, namely platinum group metals, have been de-
scribed with a variety of tertiary phosphane sulfides. The
X-ray data suggest that R3PϭS groups bind to the metal as
simple σ-donors through the p-electrons of the sulfur atom,
with no evidence of π-bonding between the metal d elec-
trons and the empty orbitals of sulfur. This situation gives
rise to weaker metal-ligand bonding than with the related
phosphane ligands.
In order to extend these studies we sought to develop
new functionalised bis(pyrazol-1-yl)methanes and to pre-
pare and characterise new metal complexes formed by these
ligands. Furthermore, we present here a modification of the
synthesis of 1 to obtain a new chiral diphosphane. The in-
fluence of sulfidation of this new diphosphane and the pre-
viously described bppzm ligand on their coordination be-
haviour was also studied. One of the resulting complexes
[a]
´
´
´
´
Departamento de Quımica Inorganica, Organica y Bioquımica,
´
Facultad de Ciencias Quımicas, Universidad de Castilla-La
Mancha, Campus Universitario de Ciudad Real,
13071-Ciudad Real, Spain
Fax: (internat.) ϩ34-926/295-318
E-mail: Antonio.Otero@uclm.es
Fernando.Carrillo@uclm.es
[b]
´
´
Instituto de Catalisis y Petroleoquımica, CSIC,
Cantoblanco, 28049, Madrid, Spain
Eur. J. Inorg. Chem. 2003, 3233Ϫ3241
DOI: 10.1002/ejic.200300202
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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A. Otero, F. Carrillo-Hermosilla et al.
FULL PAPER
was found to be active in the hydrogenation of simple olef- plexes. Chiral chelating ligands that, when complexed to a
ins.
metal such as rhodium, allow homogeneous hydrogenation
to proceed in an enantioselective fashion to yield chiral
products are of great interest and have been the focus of
many reviews.[6] Compound 2 was used in the complexation
of some late transition metal fragments, namely
[MCl2(PhCN)2] (M ϭ Pd, Pt) and [M(COD)(THF)2]BF4
(M ϭ Rh, Ir; COD ϭ cyclooctadiene), in order to test its
coordination capacity as a chelating agent (Scheme 3).
Results and Discussion
We have previously described the synthesis of bis[5-(di-
phenylphosphanyl)pyrazol-1-yl)]methane (1),[3] which was
prepared by reaction of bis(pyrazol-1-yl)methane (bpzm)
and nBuLi at low temperature, followed by the addition of
PPh2Cl and warming. In many cases a minor by-product
was observed in these reactions, although this was easily
removed by crystallization from CH2Cl2/Et2O.
The minor product has now been isolated and identified
as a new asymmetric diphosphane. In an attempt to im-
prove the yield of this new and interesting compound, the
previously described synthetic procedure was modified by
the addition of a slight excess of first nBuLi and then
PPh2Cl at room temperature, followed by recrystallization
of the product from CH2Cl2 (Scheme 1). Similar behav-
iour[5] was also observed upon the modification of bis(pyra-
zol-1-yl)methane with MeI or PhCH2Br.
Scheme 2. Ligands 1, 2, 7 and 8
Scheme 1. (i) 2.5 nBuLi, THF, room temp., 30 min; (ii) 2 PPh2Cl,
THF, room temp., 16 h
This new ligand, (diphenylphosphanyl)-[5-(diphenylphos-
phanyl)pyrazol-1-yl](pyrazol-1-yl)methane (2) (p4m), can
be obtained from the reaction mixture with good purity as
a light brown solid (see Exp. Sect.). In this procedure com-
pound 1 is formed as the by-product.
Scheme 3. (i) p4m, CH2Cl2, room temp., 5 h; (ii) bppzmS2, CH2Cl2,
room temp., 16 h; (iii) p4mS2, CH2Cl2, room temp., 16 h; (iv)
AgBF4, THF, room temp., 30 min; (v) p4m, THF, 203 K to room
temp., 3 h; (vi) p4mS2, THF, 203 K to room temp., 3 h
1
The H NMR spectrum of 2 shows two sets of two dou-
blets assigned to H3 and H4 of the two pyrazole rings, with
the more shielded peak corresponding to H4. These data
The complexes were isolated as crystalline solids in good
indicate that the two rings are not equivalent. The signal yields (see Exp. Sect.). Complexes 3, 4 and 5 are very stable
due to the bridging CH group appears as a doublet of dou- under an inert atmosphere but complex 6 slowly decom-
blets due to coupling with the two phosphorus atoms. The poses in solution.
1
JH,P coupling constants are similar to those found for anal-
The H NMR spectra of 3, 4, 5 and 6 show two sets of
ogous compounds described by us.[3] The 13C NMR spec- resonances for the H3 and H4 protons of the pyrazolyl rings.
trum confirms the asymmetry around the CH group, which In addition, the H5 proton of the unsubstituted ring ap-
gives rise to a doublet of doublets due to coupling with pears as a broad singlet. The 13C NMR spectra actually
phosphorus atoms. Finally, the 31P{1H} NMR spectrum ex- exhibit the signal for the methyne carbon atom and this
hibits two singlets at δ ϭ Ϫ30.99 and Ϫ60.94 ppm for the appears as a doublet due to coupling with the neighbouring
inequivalent phosphorus atoms.
phosphorus atom. The asymmetry of these molecules is also
Ligand 2 (Scheme 2) is of considerable interest on two reflected in the COD region of the spectra. For example,
counts; firstly due to its chiral nature and secondly because the diene ligand shows two broad peaks for the ϭCH car-
it can provide different coordination modes than compound bons. The 31P{1H} NMR spectra show two broad peaks for
1. In fact, versatile ligand 2 would form six-membered P,P-, complexes 3 and 6 and these are at significantly lower fields
six-membered N,N- or seven-membered N,P-chelating com- than the corresponding peaks for the free ligand 2, suggest-
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Late Transition Metal Complexes Bearing Diphosphane Ligands Derived from Bis(pyrazol-1-yl)methane
FULL PAPER
Figure 2. a) Molecular structure and atom-labelling scheme for compound 4; b) conformation of the six-membered chelate ring
ing that in these complexes a coordination of the p4m li- in a quasi-planar coordination. The Cl1, Cl2, P1 and P2
gand takes place in a P,P-mode. Complex 5 also exhibits atoms are co-planar and Pt1 is displaced from this plane by
˚
lower field signals but, in this case, the peaks appear as two Ϫ0.057(6) A. The six-membered chelate ring exists in a
˚
doublets of doublets due to coupling between the two cis half-boat conformation with C1 Ϫ0.96(4) A and N1
phosphorus atoms (2JP,P ϭ 39 Hz), through the metal, and Ϫ0.36(5) A out of the plane defined by Pt1, P1, P2 and C2.
˚
also due to coupling with the rhodium atom (1JP,Rh
ϭ
The PtϪP and PtϪCl distances are in reasonable agreement
115 Hz). Complex 4 shows two doublets (2JP,P ϭ 16 Hz) at with the values published for related structures.[3]
lower fields than the corresponding signals in the free li-
In contrast to the well-known use of diphosphanes as
gand and these doublets are flanked by two 195Pt satellites
chelating ligands, the coordination chemistry of phosphane
(1JPt,P ϭ 1870 and 1791 Hz, respectively).
sulfide derivatives toward platinum group metals is much
A crystal structure analysis of complex 4 was carried out
in order to confirm the proposed coordination for these
complexes. The molecular structure and atomic numbering
scheme is shown in Figure 2. Selected bond lengths and
angles for 4 are given in Table 1.
less extensively studied.[7]
The sulfide derivatives (7 and 8) of compounds 1 and 2
(Scheme 2), respectively, were obtained by reaction with an
excess of elemental sulfur (see Exp. Sect.).
In the 1H NMR spectrum of 7 the signals due to the
methylene protons are shifted to lower field than the pre-
cursor ligand 1. In a similar way to 1, compound 7 gives
rise to a single set of signals for H3 and H4 in the 1H NMR
spectrum as well as the corresponding C3, C4 and C5 car-
bon atoms in the 13C NMR spectrum. This observation
confirms the equivalence of the two pyrazole rings. Sulfid-
ation of the phosphorus atoms produces a singlet at δ ϭ
3.22 ppm in the 31P{1H} NMR spectrum, at higher field
than those found for the more simple diphosphane sulfides
such as dppmS2 (δ ϭ 35.4 ppm),[7d] and shifted to lower
field than the value found for the original diphosphane li-
gand 1. A similar effect was observed in the 31P{1H} NMR
spectrum of 8, which exhibits two singlets at δ ϭ 25.57 and
˚
Table 1. Selected bond lengths [A] and angles [deg] for 4
Pt(1)ϪCl(1)
Pt(1)ϪCl(2)
Pt(1)ϪP(1)
Pt(1)ϪP(2)
P(1)ϪC(2)
P(2)ϪC(1)
N(1)ϪC(1)
N(1)ϪC(2)
2.34(1)
2.37(1)
2.23(1)
2.20(1)
1.66(4)
1.83(3)
1.47(5)
1.41(5)
Cl(1)ϪPt(1)ϪCl(2)
Cl(1)ϪPt(1)ϪP(1)
Cl(1)ϪPt(1)ϪP(2)
Cl(2)ϪPt(1)ϪP(1)
Cl(2)ϪPt(1)ϪP(2)
P(1)ϪPt(1)ϪP(2)
Pt(1)ϪP(2)ϪC(1)
Pt(1)ϪP(1)ϪC(2)
89.8(4)
175.5(4)
89.7(4)
86.3(4)
176.7(4)
94.0(4)
116(1)
1
3.62 ppm. The H NMR signal for the proton on the me-
thyne bridge of compound 8 is also shifted to lower field
115(1)
1
than for 2. The H and 13C NMR spectra of 8 confirm the
non-equivalence of the pyrazole rings, with two sets of sig-
The structure consists of discrete monomeric molecules nals observed for the proton and carbon atoms of the pyra-
separated by van der Waals distances. The platinum centre zole rings. The IR spectra of compounds 7 and 8 show
is bound to four atoms (Figure 2b) — the two phosphorus characteristic[7d] broad ν(PϭS) bands at 658 cmϪ1 and 633
atoms from the p4m group and the two chlorine atoms — cmϪ1, respectively.
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A. Otero, F. Carrillo-Hermosilla et al.
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The molecular structure of 8 was confirmed by X-ray H4, which indicates the equivalence of the two pyrazole
crystallography. The molecular structure and atomic num- rings. A particularly interesting result was found on examin-
bering scheme are shown in Figure 3. Selected bond lengths ing the 31P{1H} NMR spectrum of 9. In this case, a singlet
and angles for 8 are given in Table 2.
for two equivalent phosphorus atoms appears at δ ϭ
4.80 ppm, which is close to the value of δ ϭ 3.22 ppm found
in the free ligand. This result seems to indicate that coordi-
nation of the phosphorus atoms to the palladium centre
does not take place and hence that the ligand behaves as an
N,N-donor in this complex. The IR spectrum confirms this
coordination mode, with a ν(PϭS) band at 660 cmϪ1, simi-
lar to the value found in the free ligand. The position of
the PϭS band in the IR spectrum of previously reported
sulfur-coordinated complexes is shifted 20Ϫ50 cmϪ1 to
lower energy relative to the corresponding band in the un-
complexed ligands.[8]
Similar PdII complexes incorporating bis(pyrazol-1-yl)-
methane ligands with N,N-coordination have been prepared
previously[9] with the aim of studying the electronic and
steric effects of these ligands on the dynamic structure and
reactivity of the corresponding complexes. In some cases,
cationic derivatives were used as ethylene polymerization
catalysts.
Figure 3. Molecular structure and atom-labelling scheme for com-
pound 8, with thermal ellipsoids at 30% probability
The analogous complex [PdCl2(bppzm)] shows a dy-
namic behaviour in solution that involves a boat-to-boat
inversion.[3] For this reason, we carried out a variable-tem-
perature NMR study in order to elucidate the possible dy-
˚
Table 2. Selected bond lengths [A] and angles [deg] for 8
P(1)ϪS(1)
P(2)ϪS(2)
P(2)ϪC(1)
P(1)ϪC(4)
N(1)ϪN(2)
N(1)ϪC(1)
N(1)ϪC(4)
N(3)ϪC(1)
1.955(1)
1.939(1)
1.897(2)
1.798(2)
1.354(3)
1.438(3)
1.367(3)
1.438(3)
1
namic behaviour of 9. In the H{31P} NMR spectrum, the
signal for the CH2 group appears as a broad singlet at δ ϭ
7.09 ppm at room temperature. At 228 K, however, this
peak disappears in the baseline but, unfortunately, a slow
exchange limit could not be observed.
The molecular structure of 9 was confirmed by X-ray
crystallography. The molecular structure and atomic num-
bering scheme is shown in Figure 4. Selected bond lengths
and angles for 9 are given in Table 3.
The structure consists of discrete monomeric molecules
separated by van der Waals distances. There are two mol-
ecules per asymmetric unit. The palladium atom is bound
to four atoms (Figure 4b) — the two nitrogens from the
bppzmS2 group and the two chlorine atoms — in a square-
planar coordination. The six-membered chelate ring exists
in a boat conformation with C4 and Pd1 out of the plane
S(1)ϪP(1)ϪC(4)
S(1)ϪP(1)ϪC(11)
S(1)ϪP(1)ϪC(21)
C(4)ϪP(1)ϪC(11)
C(4)ϪP(1)ϪC(21)
C(11)ϪP(1)ϪC(21)
S(2)ϪP(2)ϪC(1)
S(2)ϪP(2)ϪC(31)
S(2)ϪP(2)ϪC(41)
C(1)ϪP(2)ϪC(31)
C(1)ϪP(2)ϪC(41)
C(31)ϪP(2)ϪC(41)
113.9(1)
113.9(1)
114.6(1)
103.9(1)
103.0(1)
106.3(1)
112.2(1)
113.8(1)
114.2(1)
102.1(1)
106.9(1)
106.6(1)
defined by N1, N2, N3 and N4 [C4: 0.656(7) and Ϫ0.638(7)
˚
Each phosphorus atom shows a distorted tetrahedral co- A for molecules 1 and 2, respectively; Pd1: 0.624(7) and
˚
˚
ordination. The PϪS distances of 1.955(1) and 1.939(1) A Ϫ0.606(7) A for molecules 1 and 2, respectively]. The
indicate a double bond between P and S. The angle between PdϪN and PdϪCl distances are in good agreement with
the planes of the pyrazolyl rings is 112.5(1)°.
the previously published values.[9] The angle between the
In order to study the behaviour of these new compounds planes of the pyrazolyl rings is 47.6(2)° and 47.5(2)° for
as ligands in comparison to their phosphorus precursors 1 molecules 1 and 2, respectively. The angles between the
and 2, we explored the reactivity of the sulfide derivatives N1ϪN2ϪN3ϪN4 and N1ϪPd1ϪN3 planes [154.5(2)° and
7 and 8 towards Pd and Rh metal centres. In these cases, 155.3(2)° for molecules
1 and 2, respectively] and
we expect the possibility of an S,S-, N,N- or N,S-chelating N1ϪN2ϪN3ϪN4 and N2ϪC4ϪN4 planes [128.5(2)° and
coordination. Unfortunately, attempts to prepare analogous 129.8(2)° for molecules 1 and 2, respectively] are similar[3]
compounds of Pt or Ir were unsuccessful.
to that in the complex [PdCl2(bppzm)], in which steric inter-
Addition of a stoichiometric amount of 7 to a dichloro- actions are not appreciable.
methane solution of [PdCl2(PhCN)2] led to the formation
It is worth noting that [PdCl2(bppzm)], which was re-
1
of complex 9 as a very insoluble solid (Scheme 3). The H ported previously by us,[3] shows a P,P-eight-membered me-
NMR spectrum of 9 exhibits two broad singlets for H3 and tallacycle in preference to a less-open N,N-six-membered
3236
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Late Transition Metal Complexes Bearing Diphosphane Ligands Derived from Bis(pyrazol-1-yl)methane
FULL PAPER
Figure 4. a) Molecular structure and atom-labelling scheme for compound 9 (molecule 1), with thermal ellipsoids at 50% probability; b)
conformation of the six-membered chelate ring
˚
confirms an N,N-coordination on the basis of the ν(PϭS)
absorption at 630 cmϪ1 for complex 10 — a value similar
to that found in the free ligand.
Table 3. Selected bond lengths [A] and angles [deg] for 9
Molecule 1
Molecule 2
Finally, reaction of
8
and the solvate moiety
PdϪCl(1)
PdϪCl(2)
PdϪN(1)
PdϪN(3)
S(1)ϪP(1)
S(2)ϪP(2)
2.283(1)
2.282(1)
2.024(5)
2.012(5)
1.939(2)
1.937(2)
2.282(1)
2.290(1)
2.016(5)
2.027(5)
1.934(2)
1.941(2)
[Rh(COD)(THF)2]BF4 in THF afforded [Rh(COD)-
(p4mS2)]BF4 (11) as a very insoluble brown solid (see
Scheme 3). This complex was prepared in order to study
the influence of sulfur on the reactivity of complex 11 in
comparison with the analogous complex 5 (see below).
The 31P{1H} NMR spectrum of complex 11 contains two
peaks near to those of the free ligand 8. The peak at δ ϭ
20.64 ppm appears as a very broad multiplet, indicating
that some interaction with rhodium is present and that the
molecule shows a dynamic behaviour in solution. This situ-
ation was confirmed by performing a variable temperature
31P{1H} NMR study. At low temperature (213 K), the pro-
cess can be frozen out and the broad peak gives rise to a
pseudo-triplet at δ ϭ 18.76 ppm (J ϭ 9 Hz), probably due
Cl(1)ϪPdϪCl(2)
Cl(1)ϪPdϪN(1)
Cl(1)ϪPdϪN(3)
Cl(2)ϪPdϪN(1)
Cl(2)ϪPdϪN(3)
N(1)ϪPdϪN(3)
S(1)ϪP(1)ϪC(3)
S(2)ϪP(2)ϪC(7)
91.76(5)
90.6(1)
176.7(1)
177.5(1)
89.4(1)
88.2(2)
115.7(2)
112.0(2)
91.3(6)
89.8(1)
177.7(1)
176.4(1)
90.4(1)
88.4(2)
111.9(2)
115.2(2)
system. This behaviour can be explained if one considers to coupling with the rhodium and the second phosphorus.
the stable soft-soft interactions between PdII and P atoms. On the other hand, a sharp peak at δ ϭ 21.52 ppm was
In contrast, in complex 9 a stable N,N-six-membered che- observed at 333 K. A temperature-dependent coordination/
late is preferred to the soft-soft PdϪS bonds in a ten-mem- decoordination process involving one of the P(S)Ph2 groups
bered metallacycle.
was proposed as being responsible for these changes. Ad-
The behaviour of sulfur-containing ligand 8 towards ditionally, the IR spectrum shows a ν(PϭS) absorption at
[PdCl2(PhCN)2] was investigated in order to explore the 556 cmϪ1, which indicates an S,S-coordination mode.
existence of N,N-six-membered or S,S-eight-membered
Hydrogenation of Olefins
complexation. The reaction of 4 and [PdCl2(PhCN)2] was
performed in CH2Cl2 (see Scheme 3) and afforded
Complex 5, which contains the ligand p4m, is an active
[PdCl2(p4mS2)] (10) as a very insoluble solid.
hydrogenation catalyst for cyclohexene and 1-heptene
The 1H NMR spectrum of 10 shows evidence for the (Table 4).
non-equivalence of the pyrazole rings. The signal for the
The reactions were conducted under different conditions
proton of the methyne group appears as a doublet at δ ϭ of pressure, reaction time, solvent, and in the presence/ab-
9.61 ppm due to coupling with the nearest phosphorus sence of additives. In CH2Cl2, a conversion of 26% for
atom. The 31P{1H} NMR spectrum of 10 shows two sing- cyclohexene was obtained after ca. 20 h. at 10 bar and
lets at δ ϭ 26.11 and 5.70 ppm, which are closer to those of 353 K. A similar conversion (21%) was obtained in MeOH.
the free ligand (δ ϭ 25.57 and 3.62 ppm). The IR spectrum In contrast, addition of a small amount of KOH to the
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A. Otero, F. Carrillo-Hermosilla et al.
Table 4. Results of the catalysis experiments; reaction conditions: catalyst 0.03 mmol; substrate 3 mmol; solvent 30 mL; KOH 0.04 mmol
FULL PAPER
Complex
Substrate
Solvent
Additive
Time(h)
Temp.(K)
Pressure(bar)
Conversion (%)
5
5
5
5
5
cyclohexene
cyclohexene
cyclohexene
cyclohexene
1-heptene
CH2Cl2
CH2Cl2
MeOH
MeOH
MeOH
20
20
20
1
298
353
353
353
353
1
10
10
10
10
7.7
26
21
33
50
KOH
KOH
1
and [IrCl(COD)]2 were purchased from Aldrich and used as re-
ceived
latter reaction mixture produced the highest conversion ob-
served (33%) in only 1 h. The activity is similar to those
found for other rhodium derivatives of multidentate hetero-
cyclic ligands, of the type [Rh(diene)(OPPy2R)]BF4,[2j] un-
der very analogous conditions. As expected, complex 5 is a
better catalyst for the hydrogenation of 1-heptene, giving a
conversion of 50% in 1 h. The iridium derivative 6, probably
due to its lack of stability in solution, and the rhodium
complex 11, probably due to the presence of sulfur[10] in the
coordination sphere and the low solubility of this complex,
did not show any catalytic activity at all, in comparison to
the analogous phosphane complex 5.
(5-Diphenylphosphanylpyrazol-1-yl)(diphenylphosphanyl)-
(pyrazol-1-yl)methane (p4m) (2): A solution of bpzm (3 g, 20 mmol)
in dry THF (150 mL) in a 250 mL Schlenk tube was cooled to
203 K. A 1.6  solution of nBuLi (31.3 mL, 50 mmol) in hexane
was added and the solution was allowed to reach room temperature
slowly. PPh2Cl (7.27 mL, 41 mmol) was added and the reaction
mixture was stirred for 16 h. The suspension was filtered and the
solvent removed under vacuum. The resulting red oil was washed
with hexane and the residue extracted with CH2Cl2. The solvent
was removed and the resulting orange oil was washed with Et2O. A
pale-brown solid was obtained and was recrystallized from CH2Cl2.
Yield 90%. C31H26N4P2 (516.5): calcd. C 72.08, H 5.07, N 10.85%;
found C 72.20, H 5.09, N 10.49. 1H NMR (300 MHz, CDCl3,
These results suggest the possibility of testing the activity
and enantioselectivity of chiral complex 5 in the hydrogen-
ation of prochiral substrates. Experiments to obtain pure
enantiomers of ligand 2 are currently underway.
3
2
293 K): δ ϭ 7.87 (d, JH,H ϭ 2.5 Hz, 1 H, H3Ј), 7.81 (dd, JH,P
ϭ
4
3
6.0, JH,P ϭ 3.0 Hz, 1 H, CH), 7.58 (d, JH,H ϭ 2.0 Hz, 1 H, H3),
7.37Ϫ7.05 (m, 20 H, Ph), 7.24 (d, JH,H ϭ 2.0 Hz, 1 H, H5Ј), 6.08
3
3
3
3
(dd, JH,H ϭ 2.0, JH,H ϭ 2.5 Hz, 1 H, H4Ј), 5.87 (d, JH,H
ϭ
2.0 Hz, 1 H, H4) ppm. 13C{1H} NMR (75 MHz, CDCl3, 293 K):
Conclusion
1
3
δ ϭ 141.05 (d, JC,P ϭ 12.0 Hz, C5), 140.83 (d, JC,P ϭ 3.5 Hz,
C3), 139.53 (d, 3JC,P ϭ 1.5 Hz C5Ј), 135.20Ϫ128.10 (Ph), 128.94 (s,
The preparation of a new chiral functionalised phos-
phorus-containing bis(pyrazol-1-yl)methane compound,
p4m, has been carried out by modification of a previously
described procedure. The coordination modes of this com-
pound were studied towards the metal centres palladium,
platinum, rhodium and iridium to produce P,P-six-mem-
bered metallacycles. Sulfidation of the previously described
bppzm and the new p4m ligands produces the correspond-
ing sulfidodiphosphanes. The compounds p4mS2 and
bppzmS2 coordinate a palladium centre in an N,N-six-mem-
bered metallacycle and reaction of p4mS2 with
[Rh(COD)(THF)2]ϩ produces an S,S-dynamic coordi-
nation of the ligand.
2
C3Ј), 114.54 (d, JC,P ϭ 2.0 Hz, C4), 107.16 (s, C4Ј), 73.48 (dd,
1JC,P ϭ 14.0, 3JC,P ϭ 5.0 Hz, CH) ppm. 31P{1H} NMR (121 MHz,
CDCl3, H3PO4 as reference): δ ϭ Ϫ30.99 (s, PPh2), Ϫ60.94 (s,
PPh2) ppm.
[PdCl2(p4m)] (3): An equimolar quantity of p4m (0.402 g,
0.78 mmol) was added to
a CH2Cl2 (50 mL) solution of
[PdCl2(PhCN)2] (0.300 g, 0.78 mmol). The solution was stirred for
5 h at room temperature. The solvent was removed in vacuo and
the resulting pale orange solid was washed with cold CH2Cl2 and
dried in vacuo. Yield 85%. C31H26Cl2N4P2Pd (693.8): calcd. C
53.66, H 3.78, N 8.07; found C 53.89, H 3.79, N 8.01. 1H NMR
(300 MHz, CD2Cl2, 293 K): δ ϭ 7.67 (d, 2JH,P ϭ 3.0 Hz, 1 H, CH),
7.65Ϫ7.26 (m, 20 H, Ph), 7.24 (br. s, 1 H, H5Ј), 7.13 (br. s, 1 H,
H3Ј), 6.98 (br. s, 1 H, H3), 6.17 (br. s, 1 H, H4Ј), 5.92 (br. s, 1 H,
H4) ppm. 13C{1H} NMR (75 MHz, CD2Cl2, 293 K): δ ϭ 142.21
Finally, complex [Rh(COD)(p4m)]BF4 showed a moder-
ate activity in the catalytic hydrogenation of simple olefins.
1
(s, C3Ј), 140.08 (d, JC,P ϭ 13.1 Hz, C5), 136.00Ϫ128.00 (Ph),
3
2
130.80 (s, C5Ј), 129.80 (d, JC,P ϭ 11.0 Hz, C3), 118.75 (d, JC,P
ϭ
1
7.4 Hz, C4), 107.17 (s, C4Ј), 68.75 (d, JC,P ϭ 48.6 Hz, CH) ppm.
31P{1H} NMR (121 MHz, CD2Cl2, H3PO4 as reference): δ ϭ
Ϫ18.36 (s, PPh2), 15.06 (s, PPh2) ppm.
Experimental Section
All reactions were carried out using Schlenk-tube techniques under
an atmosphere of dry nitrogen. Solvents were distilled from appro-
priate drying agents and degassed before use. 1H,13C and 31P NMR
spectra were obtained on a 300 Unity Varian spectrometer. Assign-
ment of the signals was achieved by means of DEPT, NOE differ-
[PtCl2(p4m)] (4): The synthetic procedure was the same as for com-
plex 2, using [PtCl2(PhCN)2] (0.300 g, 0.64 mmol) and p4m
(0.330 g, 0.64 mmol), to give complex 4 as a white solid. Yield 90%.
Crystals for X-ray diffraction were grown from a cooled saturated
ence and two-dimensional NMR experiments, acquired using solution in CH2Cl2. C31H26Cl2N4P2Pt·4CH2Cl2 (1116.1): calcd. C
standard Varian-FT software. IR spectra were obtained in the re-
gion 500Ϫ4000 cmϪ1 using a Nicolet Magna FT-IR 550 spectro-
photometer. [MCl2(PhCN)2] (M ϭ Pd, Pt) and bis(pyrazol-1-yl)-
37.46, H 3.05, N 4.99; found C 37.50, H 3.06, N 5.02. 1H NMR
(300 MHz, CD2Cl2, 293 K): δ ϭ 7.82 (d, 2JH,P ϭ 3.0 Hz, 1 H, CH),
7.59Ϫ7.26 (m, 20 H, Ph), 7.24 (br. s, 1 H, H5Ј), 7.06 (br. s, 1 H,
methane were prepared as reported previously.[11,12] [RhCl(COD)]2 H3Ј), 6.83 (br. s, 1 H, H3), 6.16 (br. s, 1 H, H4Ј), 5.80 (br. s, 1 H,
3238
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2003, 3233Ϫ3241

Late Transition Metal Complexes Bearing Diphosphane Ligands Derived from Bis(pyrazol-1-yl)methane
H4) ppm. 13C{1H} NMR (75 MHz, CD2Cl2, 293 K): δ ϭ 141.02 H3), 7.06 (br. s, 2 H, CH2), 5.91 (d, JH,H ϭ 1.5 Hz, H4) ppm.
FULL PAPER
3
1
3
(s, C3Ј), 139.50 (d, JC,P ϭ 11.1 Hz, C5), 136.00Ϫ128.00 (Ph), 13C{1H} NMR (75 MHz, CDCl3, 293 K): δ ϭ 138.60 (d, JC,P
ϭ
3
2
130.71 (s, C5Ј), 129.65 (d, JC,P ϭ 11.0 Hz, C3), 118.48 (d, JC,P
ϭ
14.0 Hz, C3), 138.72 (d, 1JC,P ϭ 38.0 Hz, C5), 132.15Ϫ128.42 (Ph),
8.0 Hz, C4), 106.71 (s, C4Ј), 67.28 (d, JC,P ϭ 54.3 Hz, CH) ppm. 116.57 (d, 2JC,P ϭ 15.0 Hz, C4), 63.74 (s, CH2) ppm. 31P{1H} NMR
1
31P{1H} NMR (121 MHz, CD2Cl2, H3PO4 as reference): δ ϭ
(121 MHz, CDCl3, H3PO4 as reference): δ ϭ 3.22 [s, P(S)Ph2] ppm.
Ϫ34.94 (t of d, JP,Pt ϭ 1797, JP,P ϭ 16.0 Hz, PPh2), Ϫ3.03 (t of IR (KBr): ν˜ ϭ 658 cmϪ1 (s) [ν(PϭS)].
1
2
1
2
d, JP,Pt ϭ 1870, JP,P ϭ 16.0 Hz, PPh2) ppm.
(5-Diphenylphosphanylpyrazol-1-yl)(diphenylphosphanyl)-
(pyrazol-1-yl)methane Disulfide (p4mS2) (8): The synthetic pro-
cedure was the same as for compound 7, using p4m (1.000 g,
3.88 mmol) and sulfur (1.250 g, 4.85 mmol), to give compound 8
as a pale orange solid. Yield 90%. The crystals for X-ray diffraction
were grown from CH2Cl2/hexane. C31H26N4P2S2 (580.6): calcd. C
64.13, H 4.48, N 9.65; found C 64.02, H 4.62, N 9.45. 1H NMR
[Rh(COD)(p4m)]BF4 (5): An equimolar quantity of AgBF4
(0.078 g, 0.40 mmol) was added to a THF (10 mL) solution of
[Rh(COD)Cl]2 (0.100 g, 0.20 mmol). The solution was stirred for
30 min at room temperature. The precipitated AgCl was filtered off
and the filtrate was cooled to 203 K. A cooled solution of p4m
(0.103 g, 0.40 mmol) in THF (10 mL) was then added slowly. The
reaction was allowed to reach room temperature slowly over 3 h.
The solvent was removed in vacuo and the resulting yellow solid
was extracted with THF. Concentration of the solution afforded
complex 5 as a bright yellow microcrystalline solid. Yield 75%.
C39H38BF4N4P2Rh (814.4): calcd. C 57.51, H 4.67, N 6.88; found
C 57.60, H 4.80, N 6.76. 1H NMR (300 MHz, CDCl3, 293 K): δ ϭ
2
(300 MHz, CDCl3, 293 K): δ ϭ 9.35 (d, JH,P ϭ 6.8 Hz, 1 H, CH),
3
8.20Ϫ7.15 (m, 20 H, Ph), 7.83 (d, JH,H ϭ 2 Hz, 1 H, H3Ј), 7.45
3
3
(d, JH,H ϭ 2.0 Hz, 1 H, H5Ј), 6.94 (d, JH,H ϭ 2.3 Hz, 1 H, H3),
5.96 (dd, 3JH,H ϭ 2.3, JH,H ϭ 2.0 Hz, 1 H, H4Ј), 5.84 (d, JH,H
ϭ
3
3
2.3 Hz, 1 H, H4) ppm. 13C{1H} NMR (75 MHz, CDCl3, 293 K):
1
δ ϭ 139.58 (d, JC,P ϭ 14.0 Hz, C5), 139.59 (s, C5Ј), 139.37 (d,
3
3
3JC,P ϭ 2.0 Hz, C3), 136.60Ϫ127.80 (Ph), 130.32 (s, C3Ј), 116.73
8.25 (d, JH,H ϭ 2.0 Hz, 1 H, H5Ј), 8.11 (d, JH,H ϭ 2.0 Hz, 1 H,
2
2
4
4
H3Ј), 7.62Ϫ7.20 (m, 20 H, Ph), 7.59 (d, JH,P ϭ 3.0 Hz, 1 H, CH),
(dd, JC,P ϭ 14.4, JC,P ϭ 10.0 Hz, C4), 105.96 (d, JC,P ϭ 9.0 Hz,
3
3
C4Ј), 72.40 (d, JC,P ϭ 65.0 Hz, CH) ppm. 31P{1H} NMR
1
7.43 (br. s, 1 H, H3), 6.82 (dd, JH,H ϭ 2.0, JH,H ϭ 2.0 Hz, 1 H,
H4Ј), 5.99 (br. s, 1 H, H4), 4.17, 3.89 (m, 2 H, 2 H, CH, COD),
2.02, 2.33, 2.59, 2.99 (m, 2 H, 2 H, 2 H, 2 H, CH2, COD) ppm.
13C{1H} NMR (75 MHz, CDCl3, 293 K): δ ϭ 144.08 (s, C3Ј),
(121 MHz, CDCl3, H3PO4 as reference): δ ϭ 25.57 [s, P(S)Ph2],
3.62 [s, P(S)Ph2] ppm. IR (KBr): ν˜ ϭ 633 cmϪ1 (s) [ν(PϭS)].
3
[PdCl2(bppzmS2)] (9): An equimolar quantity of bppzmS2 (0.452 g,
140.63 (d, JC,P ϭ 10.0 Hz, C3), 138.00Ϫ128.00 (Ph), 133.53 (d,
1
3JC,P ϭ 2.0 Hz, C5Ј), 132.11 (d, JC,P ϭ 15.0 Hz, C5), 116.94 (d,
0.78 mmol) was added to
a CH2Cl2 (50 mL) solution of
2
2JC,P ϭ 6.0 Hz, C4), 112.03 (s, C4Ј), 86.15 (dd, JC,P ϭ 13.0,
[PdCl2(PhCN)2] (0.300 g, 0.78 mmol). The solution was stirred for
16 h at room temperature. The solvent was removed in vacuo and
the residue was washed with Et2O to give an orange solid. Yield
85%. The crystals for X-ray diffraction were grown from a cooled
saturated solution in CH2Cl2. C31H26Cl2N4P2PdS2·3.5CH2Cl2
(1055.2): calcd. C 46.45, H 3.81, N 6.47; found C 46.50, H 3.84, N
6.49. 1H NMR (300 MHz, CDCl3, 293 K): δ ϭ 8.27 (br. s, H3),
2
1
1JC,Rh ϭ 14.0 Hz, CH, COD), 84.16 (dd, JC,P ϭ 10.0, JC,Rh
ϭ
10.0 Hz, CH, COD), 72.60 (d, 1JC,P ϭ 60.3 Hz, CH), 35.93 (s, CH2,
COD), 28.54 (s, CH2, COD) ppm. 31P{1H} NMR (121 MHz,
CDCl3, H3PO4 as reference): δ ϭ 27.40 (dd, 1JP,Rh ϭ 115.0, 2JP,P ϭ
1
2
39.0 Hz, PPh2), 21.10 (dd, JP,Rh ϭ 115.0, JP,P ϭ 39.0 Hz, PPh2)
ppm.
7.70Ϫ7.54 (m, 20 H, Ph), 7.09 (br. s, 2 H, CH2), 5.99 (m, H4) ppm.
1
13C{1H} NMR (75 MHz, CDCl3, 293 K): δ ϭ 143.62 (d, JC,P
ϭ
[Ir(COD)(p4m)]BF4 (6): The synthetic procedure was the same as
for complex 5, using [Ir(COD)Cl]2 (0.100 g, 0.15 mmol) and p4m
(0.077 g, 0.30 mmol), to give complex 6 as a pale orange solid.
Yield 55%. C39H38BF4IrN4P2 (903.7): calcd. C 51.83, H 4.24, N
27.0 Hz, C5), 138.85 (d, 3JC,P ϭ 14.0 Hz, C3), 133.35Ϫ128.69 (Ph),
117.35 (d, 2JC,P ϭ 14.6 Hz, C4), 63.48 (s, CH2) ppm. 31P{1H} NMR
(121 MHz, CDCl3, H3PO4 as reference): δ ϭ 4.80 [s, P(S)Ph2] ppm.
IR (KBr): ν˜ ϭ 660 cmϪ1 (s) [ν(PϭS)].
1
6.20; found C 51.95, H 4.30, N 6.26. H NMR (300 MHz, CDCl3,
2
293 K): δ ϭ 8.43 (br. s, 1 H, H5Ј), 7.70 (d, JH,P ϭ 3.0 Hz, 1 H,
2
[PdCl2(p4mS2)] (10): The synthetic procedure was the same as for
compound 9, using [PdCl2(PhCN)2] (0.300 g, 0.78 mmol) and
p4mS2 (0.452 g, 0.78 mmol), to give compound 10 as an orange
solid. Yield 90%. C31H26Cl2N4P2PdS2 (757.9): calcd. C 49.12, H
CH), 7.60Ϫ7.20 (m, 20 H, Ph), 7.40 (d, JH,P ϭ 2.0 Hz, 1 H, H3),
3
7.31 (d, JH,H ϭ 2.0 Hz, 1 H, H3Ј), 6.45 (br. s, 1 H, H4Ј), 6.01 (br.
s, 1 H, H4), 3.80, 3.42 (m, 2 H, 2 H, CH, COD), 1.42, 2.45 (m, 4
H, 4 H, CH2, COD) ppm. 13C{1H} NMR (75 MHz, CDCl3,
1
3
3.46, N 7.39; found C 49.22, H 3.50, N 7.43. H NMR (300 MHz,
293 K): δ ϭ 142.43 (C3Ј), 139.59 (d, JC,P ϭ 10.0 Hz, C3), 134.48
2
1
CD2Cl2, 293 K): δ ϭ 9.61 (d, JH,P ϭ 7.0 Hz, 1 H, CH), 8.35 (m,
(d, JC,P ϭ 13.0 Hz, C5), 133.10 (C5Ј), 128Ϫ134 (Ph), 117.00 (d,
1
2JC,P ϭ 4.0 Hz, C4), 111.83 (C4Ј), 72.90 (d, JC,P ϭ 39.2 Hz, CH),
1 H, H5Ј), 8.02 (m, 1 H, H3Ј), 7.83Ϫ7.49 (m, 20 H, Ph), 7.45 (m,
1 H, H3), 6.15 (m, 1 H, H4), 6.13 (m, 1 H, H4Ј) ppm. 31P{1H}
NMR (121 MHz, CD2Cl2, H3PO4 as reference): δ ϭ 26.10 [s,
P(S)Ph2], 5.70 [s, P(S)Ph2] ppm. IR (KBr): ν˜ ϭ 630 cmϪ1 (s)
[ν(PϭS)].
2
2
69.12 (d, JC,P ϭ 10.0 Hz, CH, COD), 69.09 (d, JC,P ϭ 10.0 Hz,
CH, COD), 67.45 (d, 2JC,P ϭ 10.0 Hz, CH, COD), 67.43 (d, 2JC,P ϭ
10.0 Hz, CH, COD), 36.22 (CH2, COD), 36.18 (CH2, COD), 30.42
(CH2, COD) ppm. 31P{1H} NMR (121 MHz, CDCl3, H3PO4 as
reference): δ ϭ Ϫ44.26 (br. s, PPh2), 9.36 (br. s, PPh2) ppm.
[Rh(COD)(p4mS2)]BF4 (11): An equimolar quantity of AgBF4
Bis(5-diphenylphosphanylpyrazol-1-yl)methane Disulfide (bppzmS2) (0.078 g, 0.40 mmol) was added to a THF (10 mL) solution of
(7): An excess of elemental sulfur S8 (0.640 g, 2.50 mmol) was ad- [Rh(COD)Cl]2 (0.100 g, 0.20 mmol). The solution was stirred for
ded to a CH2Cl2 (50 mL) solution of bppzm (1.000 g, 2.00 mmol). 30 min at room temperature. The precipitated AgCl was filtered off
The reaction mixture was stirred for 48 h at room temperature. The
solvent was removed in vacuo and the resultant solid was washed
with CS2 (100 mL). The residue was washed with Et2O and recrys-
tallized from CH2Cl2/Et2O to afford compound 7 as a pale brown
and the filtrate was cooled to 203 K. A cooled solution of p4mS2
(0.232 g, 0.40 mmol) in THF (10 mL) was then added slowly. The
reaction was allowed to reach room temperature slowly over 3 h.
The solvent was removed in vacuo and the resulting brown solid
was extracted with THF. The solution was concentrated and cooled
solid. Yield 95%. C31H26N4P2S2 (580.6): calcd. C 64.13, H 4.48, N
1
9.65; found C 64.17, H 4.55, N 9.75. H NMR (300 MHz, CDCl3, to give complex 11 as a brown microcrystalline solid. Yield 65%.
3
293 K): δ ϭ 7.76Ϫ7.40 (m, 20 H, Ph), 7.28 (d, JH,H ϭ 1.5 Hz,
C39H38BF4N4P2RhS2 (878.5): calcd. C 53.32, H 4.36, N 6.38; found
Eur. J. Inorg. Chem. 2003, 3233Ϫ3241
www.eurjic.org
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
3239

A. Otero, F. Carrillo-Hermosilla et al.
FULL PAPER
C 53.40, H 4.42, N 6.45. 1H NMR (300 MHz, CDCl3, 293 K): δ ϭ direct methods using SHELXS[13] and refined on F2 by full-matrix
2
3
9.67 (d, JH,P ϭ 7.0 Hz, 1 H, CH), 8.42 (d, JH,H ϭ 2.0 Hz, 1 H,
least-squares (SHELXL-97).[14] The CH2Cl2 solvate molecule could
be located in complexes 4 and 9. All non-hydrogen atoms were
refined with anisotropic thermal parameters in complexes 8 and 9.
3
H3), 8.20Ϫ7.10 (m, 20 H, Ph), 7.24 (d, JH,H ϭ 2 Hz, 1 H, H3Ј),
3
3
6.72 (d, JH,H ϭ 2.0 Hz, 1 H, H5Ј), 6.51 (d, JH,H ϭ 2.2 Hz, 1 H,
3
3
H4), 6.04 (dd, JH,H ϭ 2.0, JH,H ϭ 2.0 Hz, 1 H, H4Ј), 4.32Ϫ4.17 The hydrogen atoms were included in their calculated positions and
(m, 4 H, CH, COD), 2.75Ϫ2.54 (m, 8 H, CH2, COD), 2.02Ϫ1.82 were refined with an overall isotropic temperature factor using a
(m, 8 H, CH2, COD) ppm. 13C{1H} NMR (75 MHz, CDCl3,
riding model. Weights were optimized in the final cycles. Crystallo-
3
293 K): δ ϭ 143.25 (d, JC,P ϭ 13.0 Hz, C3), 141.19 (s, C3Ј), graphic data are given in Table 5. CCDC-207627 (4), -207628 (8)
134.00Ϫ128.00 (Ph), 134.10 (d, JC,P ϭ 12.0 Hz, C5), 133.07 (s,
C5Ј), 118.60 (d, JC,P ϭ 13.0 Hz, C4), 107.01 (s, C4Ј), 79.46 (m, for this paper. These data can be obtained free of charge at
1
and -207629 (9) contain the supplementary crystallographic data
2
1
CH, COD), 77.01 (m, CH, COD), 69.00 (d, JC,P ϭ 40.1 Hz, CH),
www.ccdc.cam.ac.uk/conts/retrieving.html [or from the Cambridge
31.35 (m, CH2, COD), 29.65 (m, CH2, COD) ppm. 31P{1H} NMR Crystallographic Data Centre, 12, Union Road, Cambridge
(121 MHz, CDCl3, H3PO4 as reference): δ ϭ 20.64 [bs, P(S)Ph2], CB2 1EZ, UK; fax: (internat.) ϩ44-1223/336-033; E-mail:
4.42 [s, P(S)Ph2] ppm. IR (KBr): ν˜ ϭ 556 (s) [ν(PϭS)].
deposit@ccdc.cam.ac.uk].
X-ray Crystallographic Study: Crystals obtained for complex 4 de-
composed quickly with the loss of CH2Cl2, even when the data
collection was performed at low temperature. We attempted this
study with several crystals but data collection could not be com-
pleted. Given the importance of this structure, it was solved despite
the aforementioned problems. Intensity data for complexes 4, 8 and
9 were collected on a NONIUS-MACH3 diffractometer equipped
Catalytic Activity: Hydrogenation reactions were carried out in a
100 mL stainless steel autoclave (Magnedrive Autoclave Engineers).
The autoclave was evacuated for 2 h before a solution containing
the catalyst and substrate was introduced by suction. Hydrogen
was then introduced and the mixture was warmed to the reaction
temperature. The pressure in the autoclave was monitored using a
transducer. Samples were analysed by gas chromatography on a
Hewlett Packard HP 6890 chromatograph equipped with an FID
detector and 30 m ϫ 0.032 mm HP-Innovax column.
˚
with a graphite monochromator (Mo-Kα radiation, λ ϭ 0.71073 A)
using the ω/2θ scan technique. The final unit-cell parameters were
determined from 25 well-centered reflections and refined by the
least-squares method. The space group was determined from the
systematic absences and this was vindicated by the success of the
subsequent solutions and refinements. Two standard reflections
were measured every 60 minutes as an orientation and intensity
control; significant intensity decay was not observed for com-
pounds 8 and 9. However, compound 4 showed an intensity decay
of 56% at the end of the process. The structures were solved by
Acknowledgments
´
We gratefully acknowledge financial support from the Direccion
´
´
General de Ensen˜anza Superior e Investigacion Cientıfica (Minis-
´
terio de Educacion y Cultura), Spain (Grant. No. 1FD97Ϫ0176).
Table 5. Crystal data and structure refinement for 4, 8 and 9
4
8
9
Formula
Mol. wt.
T (K)
C31H26Cl2N4P2Pt.4CH2Cl2
1116.14
153(2)
Monoclinic
P21/n
9.229(1)
C31H26N4P2S2
580.62
293(2)
Monoclinic
P21/n
13.697(1)
14.795(1)
14.913(1)
2C31H26Cl2N4P2PdS2.7CH2Cl2
2110.32
153(2)
Cryst syst
Space group
Triclinic
¯
P1
˚
a (A)
12.460(1)
14.134(1)
25.799(1)
86.19(1)
84.98(1)
72.22(1)
4306.1(5)
1
1.628
1.193
2116
˚
b (A)
15.986(1)
29.395(1)
˚
c (A)
α (deg)
β (deg)
γ (deg)
92.12(1)
102.76(2)
3
˚
V (A )
4333.8(6)
4
1.711
3.959
2947.4(4)
4
1.308
0.317
Z
Dc (g cmϪ3
)
µ (mmϪ1
F(000)
)
2176
1208
Cryst dimens. (mm)
θ range (deg)
hkl ranges
0.1 ϫ 0.4 ϫ 0.4
1.39 to 25.11
Ϫ10 Յ h Յ 10
0 Յ k Յ 18
0 Յ l Յ 35
7756
0.3 ϫ 0.3 ϫ 0.2
2.05 to 28.01
Ϫ18 Յ h Յ 17
0 Յ k Յ 19
0 Յ l Յ 19
7676
0.2 ϫ 0.3 ϫ 0.3
2.00 to 28.00
Ϫ16 Յ h Յ 16
Ϫ18 Յ k Յ 18
0 Յ l Յ 32
21062
No. of rflns measd
No. of indep rflns
7595
7083
20607
No. of odsd rflns
3205
1.101
4693
0.991
13666
1.034
Goodness-of-fit on F2
Final R indices [I Ͼ 2σ(I)]
R1 ϭ 0.1671, wR2 ϭ 0.3927[a]
2.600/Ϫ3.862
R1 ϭ 0.0497, wR2 ϭ 0.1221
0.465/Ϫ0.513
R1 ϭ 0.0553, wR2 ϭ 0.1284
1.127/Ϫ1.094
Ϫ3
˚
Largest diff. peak (e·A
)
[a]
2
2 2
2 2
R1 ϭΣFo Ϫ Fc/ΣFo; wR2 ϭ [Σ{w(Fo Ϫ Fc ) }/Σ{w(F0 ) }]0.5
.
3240
 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2003, 3233Ϫ3241

Late Transition Metal Complexes Bearing Diphosphane Ligands Derived from Bis(pyrazol-1-yl)methane
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Received April 4, 2003
Eur. J. Inorg. Chem. 2003, 3233Ϫ3241
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 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
3241