Platinum(II) complexes bearing a thiolate/thioether ligand - Hemilability vs. dealkylation

Article abstract of DOI:10.1002/ejic.201100943

Substitution of the chloro ligands of cis-[Pt(PEt₃) ₂Cl₂] by 4-methylthio-2-thioxo-1,3-dithiole-5-thiolate (L) leads to the thiolato complexes trans-[Pt(PEt₃)₂ClL] (2) and trans-[Pt(PEt₃)₂L₂] (1), which have been characterised by X-ray crystallography. In the solid state, the square planar arrangement is capped by an endocyclic sulfur atom of L, which gives rise to distorted square-pyramidal and pseudooctahedral geometries for 2 and 1, respectively. Complex 1 coexists in solution with [Pt(PEt₃) (η¹-L)(η²-L)] (3), which results from the reversible dissociation of one phosphane ligand. The combination of η¹-(thiolato) and η²-(thiolato/thioether) L in 3 has been established by variable-temperature ¹H NMR spectroscopy and crystal structure determination. The η²-coordination mode of L is also observed in cis-[Pt(PEt₃)₂L]⁺ (4), which results from the abstraction of the chloro ligand of 2 by excess TlPF ₆. An S-demethylation reaction occurs when 1 is heated in acetonitrile to yield the structurally-characterised dithiolene complex [Pt(PEt₃)₂(dmit)] (5) (dmit^2- = 2-thioxo-1,3-dithiole-4,5-dithiolate) and MeL. Treatment of cis-[Pt(PPh ₃)₂Cl₂] with 2 equiv. of L leads to a mixture of [Pt(PPh₃)₂(dmit)] (6) and [Pt(PPh₃) (η¹-L)(η²-L)] (7). Complex 7 predominates in solution over its parent compound,[Pt(PPh₃)₂L ₂]. The identification of CH₃Cl by ¹H NMR spectroscopy proves that [Pt(PPh₃)₂ClL] is involved as an intermediate in the demethylation process. The reaction of L with platinum precursors that are blocked in a cis arrangement by chelation of 1,1-bis(diphenylphosphanyl)methane (dppm) and 1,1-bis(diphenylphosphanyl)ethane (dppe) leads to the formation of the thiolato complexes cis- [Pt(η²-dppm)L₂] (8) and cis-[Pt(η²- dppe)L₂] (9). The solid-state structure of 8 reveals the occurrence of an additional weak interaction between a thiomethyl group and the platinum centre (Pt-S 3.073 A). Copyright

Full text of DOI:10.1002/ejic.201100943

FULL PAPER
DOI: 10.1002/ejic.201100943
Platinum(II) Complexes Bearing a Thiolate/Thioether Ligand – Hemilability
vs. Dealkylation
Fabrice Guyon,*[a] Michael Knorr,[a] Aurélie Garillon,[b] and Carsten Strohmann[c]
Keywords: Platinum / S ligands / Coordination modes / C–S activation
Substitution of the chloro ligands of cis-[Pt(PEt3)2Cl2] by 4-
methylthio-2-thioxo-1,3-dithiole-5-thiolate (L) leads to the
thiolato complexes trans-[Pt(PEt3)2ClL] (2) and trans-
[Pt(PEt3)2L2] (1), which have been characterised by X-ray
crystallography. In the solid state, the square planar arrange-
ment is capped by an endocyclic sulfur atom of L, which
gives rise to distorted square-pyramidal and pseudooctahe-
dral geometries for 2 and 1, respectively. Complex 1 coexists
in solution with [Pt(PEt3)(η1-L)(η2-L)] (3), which results from
the reversible dissociation of one phosphane ligand. The
combination of η1-(thiolato) and η2-(thiolato/thioether) L in 3
has been established by variable-temperature 1H NMR spec-
troscopy and crystal structure determination. The η2-coordi-
nation mode of L is also observed in cis-[Pt(PEt3)2L]+ (4),
which results from the abstraction of the chloro ligand of 2
by excess TlPF6. An S-demethylation reaction occurs when 1
is heated in acetonitrile to yield the structurally-character-
ised dithiolene complex [Pt(PEt3)2(dmit)] (5) (dmit2– = 2-
thioxo-1,3-dithiole-4,5-dithiolate) and MeL. Treatment of cis-
[Pt(PPh3)2Cl2] with 2 equiv. of L leads to a mixture of
[Pt(PPh3)2(dmit)] (6) and [Pt(PPh3)(η1-L)(η2-L)] (7). Complex
7
predominates in solution over its parent compound,
[Pt(PPh3)2L2]. The identification of CH3Cl by 1H NMR spec-
troscopy proves that [Pt(PPh3)2ClL] is involved as an inter-
mediate in the demethylation process. The reaction of L with
platinum precursors that are blocked in a cis arrangement
by chelation of 1,1-bis(diphenylphosphanyl)methane (dppm)
and 1,1-bis(diphenylphosphanyl)ethane (dppe) leads to the
formation of the thiolato complexes cis-[Pt(η2-dppm)L2] (8)
and cis-[Pt(η2-dppe)L2] (9). The solid-state structure of 8 re-
veals the occurrence of an additional weak interaction be-
tween a thiomethyl group and the platinum centre (Pt–S
3.073 Å).
as potential hemilabile ligands (Scheme 1). Although these
systems exhibit attractive features, the literature on this
family of ligands is limited.[4] Compared to the properties
of edtMe, their chelating ability is expected to be strength-
ened due to the entropic factors that result from the use of a
rigid ethylene bridge between the thiolate and the thioether
groups. Moreover, multiple accessible oxidation states are
expected in sulfur-rich ligands with the tetrathiafulvalene
framework.[5] In these redox-active thiolate/thioether li-
gands, the binding properties could change as a function
of their oxidation state. Ligands that allow electrochemical
control over the binding properties have been termed redox-
switchable hemilabile ligands.[6] With potential applications
in catalysis or materials science in mind, we have under-
taken a study of the synthesis and properties of square-
planar complexes with mixed thiolate/thioether ligands that
possess a tetrathioethylene core. This paper reports the
preparation and reactivity of platinum(II) complexes with
Introduction
Hemilabile ligands are polydentate ligands that contain
one or several donor functionalities, which firmly bind to
the metal centre, and at least one substitutionally-labile do-
nor functionality, which allows a reversible opening–closing
mechanism upon addition of a substrate. This class of li-
gands has found increasing use in the design of catalysts
and chemosensors.[1] For this purpose, ligands that combine
hard and soft donor atoms, such as PʝO and PʝN, have
been studied extensively. However, the combination of iden-
tical atoms that lie in different environments, such as the
thiolate/thioether association, may also confer hemilabile
properties. For example, this behaviour has been studied for
an oxorhenium(V) complex coordinated by edtMe (edtH2 =
1,2-ethanedithiol).[2] In continuation of our previous studies
that concerned the coordination chemistry of dithiolene
and dithioether ligands,[3] we are interested in mixed thio-
ether/thiolate derivatives with a tetrathioethylene skeleton
hemilabile
4-methylthio-2-thioxo-1,3-dithiole-5-thiolate
(Medmit– = L). The parent dithiolene ligand, 2-thioxo-1,3-
dithiole-4,5-dithiolate (dmit2–), is one of the most studied
dithiolene ligands and has applications in conducting mate-
rials.[7] The coordinating ability and structural aspects of L
have been studied by Olk et al. with several other transition
metals.[4a,4b] Its coordination mode has been identified as
monodentate through the thiolate sulfur atom in (Ph3P)3-
[a] Institut UTINAM, UMR CNRS 6213, Université de Franche-
Comté, Faculté des Sciences et des Techniques,
16 Route de Gray, 25030 Besançon, France
E-mail: fabrice.guyon@univ-fcomte.fr
[b] SERAC – UT Spectro, Technopole Temis,
18 rue Alain Savary, 25000 Besançon, France
[c] Anorganische Chemie, Technische Universität Dortmund,
Otto-Hahn-Strasse 6, 44227 Dortmund, Germany
282
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Platinum(II) Complexes Bearing a Thiolate/Thioether Ligand
1
AgL, (Ph3P)2AuL, Cp2TiL2, (tmeda)ZnL2 [tmeda = 1,2- coupling constant JP,Pt of 2372 Hz is consistent with the
bis(dimethylamino)ethane] and (dppe)PdL2 [dppe = 1,2-
bis(diphenylphosphanyl)ethane], whereas the mixed thio-
late/thioether ligand acts as a bidentate ligand in (Ph3P)2-
CuL. Interestingly, both coordination modes coexist in
(dppe)NiL2. To develop this topic further, our contribution
focuses on the complexation of L with platinum(II). We in-
vestigated the reactivity of the coordinated ligand and the
influence of the nature of the ancillary ligand on the coordi-
nation mode.
trans configuration of the ligands around the platinum cen-
tre.[8] Modification of the nature of the solvent, for example
MeOH or acetone, had no influence on the configuration
of the resulting material. Monomeric complexes of the type
[Pt(PR3)2(SR)2] have already been studied in the context of
cis–trans isomerisation.[9] The formation of trans species has
been observed during the substitution of chloro ligands by
thiolate[8a,10] and in solution for an isolated cis-[Pt(PR3)2-
(SR)2] complex.[11] To gain more information about the iso-
merisation process that occurs during the formation of 1,
we reacted L with an equimolar amount of cis-[Pt(PEt3)2-
Cl2], which was solubilised in acetone with a relatively high
dilution. After 1 h of reaction at ambient temperature,
trans-[Pt(PEt3)2LCl] (2) was extracted into hexane from the
unreacted starting material along with a small amount of
1. Upon cooling, 2 was isolated as yellow crystals. The
31P{1H} NMR spectrum of 2 shows an unique signal at
Scheme 1.
1
14.5 ppm, which is flanked by two satellites with JP,Pt of
2387 Hz. These data are in agreement with two magneti-
cally equivalent phosphorus ligands in a trans arrangement.
1H NMR analysis reveals the presence of a singlet at
2.41 ppm. The integration ratio between this signal and
those of the ethyl groups fits with the stoichiometry of 2.
The cis–trans isomerisation may occur at the first stage of
the substitution to minimise the steric hindrance between
the two PEt3 ligands. The five-coordinate intermediate that
results from the associative activation in square-planar sub-
stitution reactions favours the rearrangement, which takes
place at ambient temperature. In contrast, in the reaction
of PtCl2 with 2 equiv. of tri-n-butylphosphane, which has
approximately the same basicity and cone angle as PEt3,
isomerisation from the kinetic product, cis-[Pt(PBu3)2Cl2],
Results and Discussion
Substitution of Chlorine by L in cis-[Pt(PEt3)2Cl2]
The reaction of cis-[Pt(PEt3)2Cl2] with 2 equiv. of CsL in
dichloromethane yielded trans-[Pt(PEt3)2L2] (1) as an ochre,
air-stable powder (Scheme 2). Complex 1 is highly soluble
in halogenated solvents, but poorly soluble in acetone and
methanol. A cyclic voltammetry study performed in
CH2Cl2 showed that 1 is irreversibly oxidised at ca. 0.8 V
vs. AgClO4/Ag (0.1 m in MeCN). The hydrogen atoms of
the thiomethyl groups appear as a singlet at 2.44 ppm in
the 1H NMR spectrum, which excludes any coupling in
solution between these protons and the metal. The 31P{1H}
NMR spectrum of 1 displays a singlet at 12.5 ppm, and the
Scheme 2.
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F. Guyon, M. Knorr, A. Garillon, C. Strohmann
FULL PAPER
to the thermodynamic product, trans-[Pt(PBu3)2Cl2], re- chloro ligand. In contrast, due to the more pronounced
quires a much higher temperature.[12] Moreover, 31P NMR trans influence of the thiolato ligand, the Pt–Cl bond length
monitoring of the substitution evidences a singlet at of 2.3619(15) Å is significantly longer than that in trans-
12.1 ppm (1JPt,P 2895 Hz), the intensity of which decreases [Pt(PEt)3Cl2] (2.294 Å).[14] The Pt–P bond lengths of
with time. This signal is tentatively assigned to a square- 2.3279(16) and 2.3179(16) Å are in the same range as those
pyramidal intermediate of the type cis-[Pt(PEt3)2Cl2L] of trans-[Pt(PEt)3Cl2] [2.300(19) Å] and 1. The coordination
(Scheme 2).
sphere of Pt involves two phosphorus atoms, a chloro li-
Crystallographic analysis of 1 confirms a centrosymmet- gand and a thiolato sulfur atom with cis angles lying be-
ric, trans-bis(thiolato) structure (Figure 1). The Pt atom dis- tween 87.48(6) and 92.35(6)°. Similar to the situation de-
plays a slightly distorted square-planar coordination with scribed in 1, the square-planar arrangement is capped by
P–Pt–S angles of 86.415(15) and 93.585(15)°. The tetrathio- an endocyclic sulfur atom of L. However, the interaction is
ethylene unit is perpendicular to the coordination sphere more pronounced in 2 as the Pt···S contact is shortened to
of Pt with a P–Pt–S(1)–C(1) dihedral angle of 100.5°. The 3.193 Å. Therefore, the coordination environment around
Pt–P distance of 2.3339(5) Å and the Pt–S distance of the Pt centre in the solid state is best described as distorted
2.3345(5) Å are similar to those reported for other trans- square-pyramidal. In addition, molecules of 2 are organised
[Pt(PEt3)2(thiolate)2] compounds.[8b,13] No interaction be- in centrosymmetric dimers within the unit cell with a paral-
tween the thiomethyl groups and the Pt atom is obvious in lel orientation of the dmit core. The plane-to-plane separa-
the solid state. In contrast, the Pt···S(2) contacts of 3.328 Å, tion is 3.45 Å, and the shortest S···S distance is 3.601 Å.
which are slightly shorter than the sum of the correspond- This supramolecular assembly is not surprising as the abil-
ing Van der Waals radii, suggest an incipient octahedral ity of dmit to develop a network of intermolecular interac-
geometry for this complex, which is corroborated by the tions through short S···S contacts is well documented.[15]
Pt–S(1)–C(1)–S(2) dihedral angle of 0.657°.
Evolution of 1 in Solution – Hemilability vs. Demethylation
An additional weak peak with two satellites is observed
at 16.5 ppm (1JP,Pt = 3348 Hz) in the 31P{1H} NMR spec-
trum of 1 (Figure 3). This signal, and another singlet at
54.7 ppm, became more intense after the sample was stored
for several days at 278 K. Concomitantly, the peak due to
the phosphane ligands disappears. The nature of
[Pt(PEt3)(η1-L)(η2-L)] (3), which results from the transfor-
mation of 1, was established unambiguously by crystal
structure determination after crystallisation by addition of
hexane to a CDCl3 solution (Figure 4).
Figure 1. Molecular structure of 1. H atoms are omitted for clarity.
Selected bond lengths [Å] and angles [°]: Pt–S(1) 2.3345(5), Pt–
P 2.3339(5), C(1)–S(1) 1.7377(18), C(1)–C(2) 1.352(2), C(2)–S(5)
1.7521(18), S(5)–C(4) 1.806(2), S(1)–Pt–P 86.415(15), S(1)–Pt–P#
93.585(15), Pt–S(1)–C(1) 106.00(6), C(2)–S(5)–C(4) 99.73(9).
The structure of 2 is shown in Figure 2. The thiolate li-
gand lies trans to the chloro ligand. The Pt–S(1) distance
of 2.3011(15) Å is similar to that in 1 and is in accord with
the weak thermodynamic trans influence exerted by the
Figure 2. Molecular structure of 2. H atoms are omitted for clarity.
Selected bond lengths [Å] and angles [°]: Cl–Pt 2.3619(15), P(1)–Pt
2.3279(16), P(2)–Pt 2.3179(16), Pt–S(1) 2.3011(15), C(3)–S(1)
1.737(6), C(2)–C(3) 1.350(8), C(2)–S(2) 1.748(6), C(4)–S(2)
1.790(8), S(1)–Pt–P(2) 92.35(6), S(1)–Pt–P(1) 87.48(6), P(2)–Pt–
P(1) 172.50(6), S(1)–Pt–Cl 176.73(6), P(2)–Pt–Cl 87.52(5), P(1)–Pt– Figure 3. 31P{1H} NMR spectra (CDCl3 solution) of 1 (top) and 3
Cl 92.23(5), C(3)–S(1)–Pt 103.1(2), C(2)–S(2)–C(4) 102.0(4).
(bottom).
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Platinum(II) Complexes Bearing a Thiolate/Thioether Ligand
Figure 4. Molecular structure of 3. H atoms are omitted for clarity.
Selected bond lengths [Å] and angles [°]: Pt–S(4) 2.3052(10), Pt–
S(9) 2.3278(10), Pt–S(5) 2.3418(10), Pt–P 2.2593(11), S(4)–C(8)
1.723(4),
C(8)–C(9)
1.332(5),
C(9)–S(5)
1.755(4),S(5)–
C(10),1.806(4), S(9)–C(12) 1.751(4), C(12)–C(13) 1.341(5), C(13)–
S(10) 1.738(4), S(10)–C(14) 1.784(4), P–Pt–S(4) 92.40(4), P–Pt–S(9)
86.47(4), S(4)–Pt–S(9) 178.65(4), P–Pt–S(5) 177.89(3), S(4)–Pt–S(5)
89.51(4), S(9)–Pt–S(5), 91.63(5), Pt–S(4)–C(8) 101.10(13), S(4)–
C(8)–C(9) 126.6(3), C(8)–C(9)–S(5) 121.2(3), C(9)–S(5)–Pt
101.51(14), C(9)–S(5)–C(10) 102.77(18), C(10)–S(5)–Pt 104.38(15),
Pt–S(9)–C(12) 106.67(13), S(9)–C(12)–C(13) 125.2(3), C(12)–
C(13)–S(10) 122.7(3), C(13)–S(10)–S(14) 102.7(2).
Compound 3 bears only one phosphane ligand and the
coordination demand of the PtII atom is satisfied by a sup-
plementary strong dative interaction with one thiomethyl
group. In solution, the two thiomethyl groups are equiva-
1
Figure 5. H NMR spectra of 3 (CDCl3 solution) recorded at 298
and 223 K.
lent at 293 K as only one signal is observed for these sub-
1
stituents in the H NMR spectrum at 2.68 ppm (a poorly oxidation of the triethylphosphane to its corresponding
4
resolved doublet with JP,H = 1.4 Hz) with satellites due to weakly-coordinating phosphane oxide (responsible for the
3JPt,H of 14 Hz. In contrast, the exchange of the coordi- signal at δ = 54.7 ppm in the 31P{1H} NMR spectrum, see
nated thiomethyl groups on platinum is slow at 223 K, and above), which displaces the balance in favour of 3. No reac-
at this temperature, two singlets are found at 2.89 and tion is observed when 3 is treated with excess CsL.
2.46 ppm (Figure 5). The evaluation of the coalescence tem-
The η2-coordination mode of L is also observed in
perature (Tc = 240 K) and Δν value in the low exchange [Pt(PEt3)2(η2-L)]+ (4), which resulted from the abstraction
limit allows the calculation of an activation energy ΔG‡ of of the chloro ligand of 2 by excess TlPF6 (Scheme 2). This
47 kJmol–1 with the Eyring equation.
reaction was monitored by 31P{1H} and 1H NMR spec-
In the solid state, two types of L are clearly identified. troscopy. The spectra prove unambiguously that the vacant
The first is ligated to the platinum through a covalent Pt– coordination site on platinum is electronically saturated by
S(thiolate) bond of 2.3278(10) Å. The second ligand che- a strong interaction with the thiomethyl group, which pro-
lates the metal with Pt–S(thiolate) and Pt–S(thioether) dis- vides a 16 electron count. Indeed, the 31P{1H} NMR spec-
tances of 2.3052(10) and 2.3418(10) Å, respectively. As trum consists of two mutually coupled doublets at 13.3 and
mentioned in the introduction, such a combination of η1- 9.4 ppm (2JP,P = 22 Hz), which indicates the nonequivalence
and η2-L ligands has already been observed in [Ni(dppe)- of the two phosphanes. The high-field resonance exhibits a
L2]. However, in this case, the difference in strength of the 1J coupling of 2702 Hz to the 195Pt nucleus, whereas the
1
interactions between the metal centre and the two types of low-field resonance displays a JPt,P coupling of 3048 Hz.
1
sulfur atoms is much more pronounced.[4b] Compared to In the H NMR spectrum, the thiomethyl protons resonate
the value measured in centrosymmetric 1, the Pt–P bond in at 2.95 ppm, which is similar to that observed in 3. The
4
3
3, trans to Pt–Sthioether, is significantly stronger [2.2593(11) coupling constants JP,H and JPt,H of 3.1 and 33 Hz,
vs. 2.3339(5) Å]. The distances measured for the trans Pt–P respectively, are significantly stronger in 4. These observa-
and Pt–Sthioether bonds compare well with those reported tions corroborate a strong η2-coordination mode of L and
for cis-[(Et3P)ClPt1{S(MeS2)=C(S3Me)S}Pt2Cl(PEt3)(Pt1– the rearrangement of the phosphane ligands from a trans
S3)(S2–Pt2)] [Pt–S 2.311(9) and 2.335(10) Å; Pt–P to a cis conformation.
2.267(10) and 2.249(10) Å].[4c] Due to the hemilability of
Heating a solution of 1 in acetonitrile overnight led to
L, 1 and 3 coexist in solution in the equilibrium mixture the formation of [Pt(PEt3)2(dmit)] (5) and liberation of 4,5-
1p3 + PEt3 with a small equilibrium constant (Scheme 2). bis(methylthio)-1,3-dithiole-2-thione, which indicates that a
Indeed, from the integration of the signals at 2.68 (3) and methyl migration from one sulfur ligand to the other occurs
1
2.44 ppm (1) in the H NMR spectrum of a pure sample of at high temperature (Scheme 2). The 31P{1H} NMR spec-
1 in CDCl3, the [1] to [3] ratio can be estimated to be 17:1. trum of 5 consists of a singlet at 6.5 ppm, which is coupled
The complete transformation of 1 is a consequence of the to platinum (1JP,Pt = 2798 Hz). An X-ray structure analysis
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285

F. Guyon, M. Knorr, A. Garillon, C. Strohmann
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of 5 confirmed unambiguously that the demethylation reac- the formation of [Pt(PPh3)(η1-L)(η2-L)] (7). This hypothesis
tion occurred. The coordination sphere of the PtII complex is confirmed by the detection of the signal of free tri-
is square planar and consists of a chelating dithiolene and phenylphosphane at –3.7 ppm in the 31P NMR spectrum of
two cis PEt3 ligands. The structure depicted in Figure 6 is the crude product. Moreover, dynamic behaviour similar to
1
very similar to those of other structurally characterised het- that reported for 3 was observed in solution. The H NMR
eroleptic phosphane(dithiolene)platinum(II) complexes, spectrum recorded at 293 K displays one broad resonance
particularly [Pt(PPh3)2(dmit)].[16] In 5, the Pt–S bond at 2.61 ppm, which is split into two singlets at 2.95 and
lengths of 2.3408(16) and 2.3314(17) Å are also similar to 2.27 ppm at low temperature. In contrast, heating the sam-
3
those in 1. Great attention has been paid to metal-assisted ple to 320 K gives rise to a sharp singlet with a JPt,H cou-
C–S bond activation from synthetic, catalytic and bioinor- pling of 15 Hz. As in 3, the two sulfur ligands mutually
ganic standpoints. The C–S bond cleavage evidenced in 1 is exchange their coordination mode from η1-thiolato to a
not without precedent. The conversion of thioether com- chelating one that involves both Pt–S(thiolate) and Pt–
plexes into thiolato compounds by dealkylation has been S(thioether) interactions (Scheme 3) with an activation en-
observed in numerous group VIII metal complexes of NʝS, ergy ΔG‡ of 46.1 kJmol–1 (at Tc = 241 K). By adding a large
PʝS, AsʝS and SʝS donor chelates.[17] Such alkyl ex- excess of triphenylphosphane to a CDCl3 solution of 7, the
trusion may result from photoreactions,[18] electrochemical resonance due to compound 7 disappears in the 31P{1H}
reductions,[19] reactions with nucleophiles[20] or under high- NMR spectrum, and a new singlet at 19.8 ppm with a JPt,P
temperature conditions.[21] It should, however, be men- coupling of 3054 Hz arises. This signal, and that observed
tioned that boiling an acetone solution of trigonal-planar in the 1H NMR spectrum at 2.23 ppm, indicates the forma-
[Au(PPh3)2L] resulted not in C–S bond activation but in the tion of [Pt(PPh3)2(η1-L)2]. From these observations, we can
dissociation of one of the phosphane ligands, which led to conclude that the monophosphane complex is the main
a linear, two-coordinate gold(I) centre in [Au(PPh3)L].[4a]
product in the equilibrium [Pt(PR3)2(η1-L)2] p [Pt(PR3)(η1-
L)(η2-L)] + PR3 (R = Ph), whereas the use of the more
basic triethylphosphane stabilises the diphosphane com-
plex. Complex 7 is not sensitive to the presence of acetoni-
trile even in excess. Single crystals of 7 were grown from
CHCl3/CH3CN. Two independent [Pt(PPh3)(η1-L)(η2-L)]
molecules are located in general positions in the unit cell,
which differ mainly in the orientation of the sulfur ligand
that is coordinated in the η1 mode. The molecular structure
Figure 6. Molecular structure of 5. H atoms are omitted for clarity.
Selected bond lengths [Å] and angles [°]: P(1)–Pt 2.2971(18), P(2)–
Pt 2.2931(16), Pt–S(2) 2.3314(17), Pt–S(1) 2.3408(16), C(1)–S(1)
1.748(6), C(2)–S(2) 1.735(6), C(1)–C(2) 1.349(9), P(2)–Pt–P(1)
98.60(5), P(2)–Pt–S(2) 88.28(5), P(1)–Pt–S(2) 173.10(5), P(2)–Pt–
S(1) 176.36(5), P(1)–Pt–S(1) 83.84(5), S(2)–Pt–S(1) 89.33(5), C(1)–
S(1)–Pt 101.7(2), C(2)–S(2)–Pt 101.4(2), C(2)–C(1)–S(1) 122.6(5),
C(1)–C(2)–S(2) 124.9(5).
Influence of the Nature of the Phosphane Ligand
i) PPh3 vs. PEt3
In order to evaluate the influence of the nature of the
phosphane ligand on the reactivity described above, CsL
was also reacted with the cis-[Pt(PPh3)2Cl2]. The reaction
was first studied in dichloromethane at ambient tempera-
ture using a 2:1 ligand-to-metal ratio. The 31P{1H} NMR
spectrum of the crude product mixture showed the forma-
tion of two complexes, which are characterised by singlets
at 18.4 and 17.3 ppm with JP,Pt couplings of 2961 and
3585 Hz, respectively. The two complexes were separated by
chromatography on silica gel. On the basis of the NMR
spectroscopic data reported by Bereman et al., the low-field
resonance is attributed to [Pt(PPh3)2(dmit)] (6).[16,22] Con-
cerning the species responsible of the chemical shift at
17.3 ppm, the strong value of the associated coupling con-
stant compares well with that observed for 3 and suggests Scheme 3.
286
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Platinum(II) Complexes Bearing a Thiolate/Thioether Ligand
Table 1. Pt–P and Pt–S bond lengths [Å] in the molecular structures determined in this work.
1
2
3
5
7[a]
8
Pt–P
2.3339(5)
2.3279(16)
2.3179(16)
2.3011(15)
2.2593(11)
2.2971(18)
2.2931(16)
2.3314(17)
2.3408(16)
2.2459(10)
2.2504(10)
2.2504(10)
2.2415(10)
2.3622(10)
2.3689(10)
Pt–Sthiolate
Pt–Sthioether
2.3345
2.3052(10)
2.3278(10)
2.3418(10)
2.2892(9)
2.3379(9)
2.3303(9)
2.2937(9)
2.3359(9)
2.3217(9)
[a] Two independent molecules in the unit cell.
of 7 is similar to that of 3 with a square-planar environment amount of cis-[Pt(PPh3)2Cl2] solubilised in acetone in high
around the platinum centre composed of one phosphorus dilution. The mixture immediately turned yellow, and, an
atom, two thiolate sulfur atoms and one thioether sulfur ochre powder was isolated after workup. The 31P NMR
atom (Figure 7). The nature of the phosphane (PPh3 vs. spectrum revealed signals arising from 6 and 7 as well as a
PEt3) does not significantly affect the Pt–P and Pt–S bond singlet at 15.5 ppm with JPt,P equal to 3130 Hz, which is
lengths (Table 1). The Pt–Sthioether bond trans to the phos- tentatively assigned to the complex resulting from the
phane is only slightly stronger with PPh3 [2.3303(9) and monosubstitution of
a chloro ligand, [Pt(PPh3)2ClL]
2.3217(9) vs. 2.3418(10) Å].
(Scheme 3). More informative is the evolution of the sam-
ple. After storage for one week at 278 K, only the resonance
1
due to 6 was detected in the 31P NMR spectrum. The H
NMR spectrum exhibits an intense singlet at 3.01 ppm,
which indicates the formation of CH3Cl. Based on this ob-
servation, a mechanism for the demethylation reaction is
proposed starting from [Pt(PPh3)2ClL]. The first step is the
oxidative addition of the S–CH3 bond, which leads to a
labile hexacoordinate PtIV species, [Pt(PPh3)2(dmit)ClMe].
This intermediate evolves to 6 by the reductive elimination
of chloromethane. Thus, the reactivity and the coordinating
mode of L in platinum complexes can be tuned by the na-
ture of the ancillary phosphane ligands.
ii) Using Chelating Diphosphanes
Figure 7. Molecular structure of 7 (only one of the two independent
molecules of the unit cell is depicted). H atoms are omitted for
clarity. Selected bond lengths [Å] and angles [°]: P(1)–Pt(1)
2.2459(10), Pt(1)–S(1) 2.2892(9), Pt(1)–S(1) 2.3303(9), Pt(1)–S(6)
2.3379(9), P(1)–Pt(1)–S(1) 93.41(3), P(1)–Pt(1)–S(2) 175.50(3),
S(1)–Pt(1)–S(2) 90.55(3), P(1)–Pt(1)–S(6) 87.20(3), S(1)–Pt(1)–S(6)
178.54(4), S(2)–Pt(1)–S(6) 88.89(3). For the second molecule: Se-
lected bond lengths [Å] and angles [°]: P(2)–Pt(2) 2.2504(10), Pt(2)–
S(11) 2.2937(9), Pt(2)–S(12) 2.3217(9), Pt(1)–S(16) 2.3359(9), P(2)–
Pt(2)–S(11) 91.95(3), P(2)–Pt(2)–S(12) 174.81(3), S(11)–Pt(2)–S(12)
90.26(3), P(2)–Pt(2)–S(16) 90.73(3), S(11)–Pt(2)–S(16) 176.98(3),
S(12)–Pt(2)–S(16) 86.95(3).
The reaction of CsL with platinum precursors blocked
in a cis arrangement with the chelating diphosphanes 1,1-
bis(diphenylphosphanyl)methane (dppm) and dppe allows
the formation of the air-stable complexes cis-[Pt(η2-dppm)-
L2] (8) and cis-[Pt(η2-dppe)L2] (9) (Scheme 3). The 31P{1H}
NMR spectra for 8 and 9 display singlet resonances with
platinum satellites at –48.1 (1JP,Pt = 2585 Hz) and 47.1 ppm
1
(1JP,Pt = 2974 Hz), respectively. In the H NMR spectra,
the resonance of the S–CH3 groups gives rise to singlets at
2.34 ppm for 8 and 2.26 ppm for 9. Again, no interaction
seems to occur in solution between the platinum centre and
The nature of the phosphane donor plays also a role in thiomethyl group(s). Complexes 8 and 9 were also isolated
the rate of the demethylation reaction. As mentioned above, quantitatively by adding one equivalent of dppm or dppe
the formation of 7 was always accompanied by 6, even to 7 (Scheme 3). The reactivity is somewhat different start-
when the substitution reaction was performed at 273 K. At ing from 3. Indeed, addition of one equivalent of dppm to
first glance, the increase of the rate of formation of the di- 3 resulted in the formation of an equimolar mixture of 8,
thiolene compound on going from PEt3 to PPh3 ancillary [Pt(PEt3)2L2] and unreacted dppm (see Supporting Infor-
ligands is surprising because of the predominant species in mation), whereas dppe displaces the triethylphosphane to
solution (diphosphane vs. monophosphane complex). In- give 9 almost quantitatively (Scheme 2). This example illus-
deed, we have shown above that [Pt(PEt3)2(dmit)] was trates the higher stability of the five-membered metallacycle
formed by heating a solution of [Pt(PEt3)2L2]. In order to compared to the four-membered one. The molecular struc-
gain more information on the species involved in the de- ture of 8 was determined by a single-crystal X-ray diffrac-
alkylation process when triphenylphosphane is coordinated tion study. The cis arrangement of the L ligands in 8 with
to the platinum centre, we reacted CsL with an equimolar a S(1)–Pt–S(6) angle of 88.59(4)° is shown in Figure 8. The
Eur. J. Inorg. Chem. 2012, 282–291
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287

F. Guyon, M. Knorr, A. Garillon, C. Strohmann
FULL PAPER
P(1)–Pt–P(2) angle of 74.05(4)° and the Pt–P distances of [PtP2L2]-type complexes. The dative interaction leads to the
2.2504(10) and 2.2415(10) Å are typical of dppm chelated displacement of a phosphane ligand (hemilabile behaviour)
to platinum.[23] Compared to the situation described above or to the activation of the C–SMe bond on the platinum
for trans 1 and 2, the platinum–thiolato bonds are slightly centre to generate a dithiolene complex. These results are
elongated to 2.3622(10) and 2.3689(10) Å (Table 1). Again, very encouraging for the purpose of extending our research
the coordination environment around the platinum centre to other thiolate/thioether–platinum complexes, especially
is best described as distorted square-pyramidal as an ad- by introducing a reversibly oxidisable ligand with a coordi-
ditional short Pt···S contact of 3.073 Å is observed. In this nation mode determined by its oxidation state. In light of
case, the S(2) sulfur atom involved belongs to a thiomethyl the reactivity of the Pt–H bond towards insertion reactions,
group; for the other L ligand, the sulfur thiomethyl atom we are currently probing the synthesis of platinum–hydride
S(7) is located at 3.692 Å. The apical Pt···S distance of 8 complexes that bear this thiolate/thioether ligand system.
approaches the values reported in platinum(II)–1,4,7-tri-
thiacyclononane complexes (2.84–2.97 Å).[24] The molecu-
lar structure of 8 compares well with that reported for the
analogous compound cis-[Pd(η2-dppe)L2], in which a close
Pd···S(thiomethyl) contact of 3.11 Å was pointed out.[4b]
The intermolecular interactions observed in the solid-state
packing diagram of 8 along the bc plane are worth men-
tioning; the S···S contacts of 3.416 Å (S4···S8) and 3.421 Å
(S3···S3) fall below the sum of the Van der Waals radii of
two S atoms (3.70 Å) and give rise to a 2D supramolecular
network (see Supporting Information).
Experimental Section
General: All manipulations were performed using Schlenk tech-
niques in an atmosphere of dry oxygen-free argon. Elemental
analyses were performed with a Leco Elemental Analyser CHN
900. 31P{1H} NMR spectra were recorded at 300.13 MHz with a
Bruker DRX 300 spectrometer. CsL,[4b] cis-[Pt(PEt3)2Cl2],[25] cis-
[Pt(PPh3)2Cl2],[26] [Pt(dppm)Cl2][27] and [Pt(dppe)Cl2][28] were pre-
pared according to literature procedures.
trans-[Pt(PEt3)2(L1)2] (1): A CH2Cl2 (20 mL) solution of cis-
[Pt(PEt3)2Cl2] (0.240 g, 0.48 mmol) and caesium 4-methylthio-2-
thioxo-1,3-dithiole-5-thiolate (CsL, 2 equiv., 0.330 g, 0.96 mmol)
was stirred overnight at room temperature. After filtration, the
solution was concentrated under reduced pressure. Ochre single
crystals were grown by the addition of hexane (245 mg, 60%).
C20H36P2PtS10 (854.12): calcd. C 28.12, H 4.25, S 37.54; found C
1
27.84, H 4.05, S 37.20. H NMR (CDCl3, 298 K): δ = 2.44 (6 H,
S–CH3), 2.02 (m, 12 H, P–CH2–), 1.16 (m, 18 H, CH2–CH3) ppm.
31P{1H} NMR (CDCl3, 298 K):
δ
=
12.5 (s, 1J
=
195Pt,31
P
2372 Hz) ppm. IR (KBr): ν = 2961, 2930, 1437, 1059 (C=S), 1032
˜
(C=S), 1007, 890, 760, 729 cm–1.
trans-[Pt(PEt3)2ClL] (2): To an acetone (30 mL) solution of cis-
[Pt(PEt3)2Cl2] (0.200 g, 0.40 mmol) was added dropwise CsL
(0.135 g, 0.39 mmol) dissolved in acetone (10 mL). After stirring
the mixture at room temperature for 3 h, the solution was filtered,
and the filtrate was evaporated to dryness. The residue was then
extracted into hexane (4ϫ 10 mL), and the combined extracts were
concentrated in vacuo. Cooling the solution to 253 K precipitated
yellow needles of 2 (95 mg, 36%). C16H33ClP2PtS5 (678.24): calcd.
C 28.33, H 4.90, S 37.54; found C 28.58, H 5.03, S 36.87. 1H NMR
(CDCl3, 298 K): δ = 2.41 (3 H, S–CH3), 1.98 (m, 12 H, P–CH2–),
Figure 8. Molecular structure of complex 8. For clarity, H atoms
are omitted and only Cipso of the phenyl groups are represented.
Selected bond lengths [Å] and angles [°]: P(1)–Pt 2.2504(10), P(2)–
Pt 2.2415(10), Pt–S(1) 2.3622(10), Pt–S(6) 2.3689(10), S(2)–C(28)
1.794(5), C(25)–S(2) 1.743(4), C(25)–C(26) 1.354(5), C(26)–S(1)
1.726(4), C(29)–S(6) 1.737(4), C(29)–C(30) 1.331(6), C(30)–S(7)
1.753(4), C(32)–S(7) 1.788(4), P(2)–Pt–P(1) 74.05(4), P(2)–Pt–S(1)
172.75(4), P(1)–Pt–S(1) 98.69(4), P(2)–Pt–S(6) 98.66(4), P(1)–Pt–
S(6) 172.65(4), S(1)–Pt–S(6) 88.59(4), C(26)–S(1)–Pt 105.48(14),
C(25)–C(26)–S(1) 130.3(3), C(26)–C(25)–S(2) 125.6(3), C(25)–S(2)–
C(28) 100.9(2), C(29)–S(6)–Pt 106.74(14), C(30)–C(29)–S(6)
127.2(3), C(29)–C(30)–S(7) 121.9(3), C(30)–S(7)–C(32) 102.9(2).
1.16 (m, 18 H, CH2–CH3) ppm. 31P{1H} NMR (CDCl3, 298 K): δ
1
195Pt,31
P
= 14.5 (s, J
= 2387 Hz) ppm.
[Pt(PEt3)(η1-L)(η2-L)] (3): Complex 1 (0.043 g, 0.05 mmol) was
dissolved in oxygenated CH2Cl2 (10 mL) and let for two weeks at
278 K. A layer of hexane was added, and 3 was afforded as dark
crystals after a few days (30 mg, 82%). C14H21PPtS10 (736.05):
calcd. C 22.84, H 2.88, S 43.56; found C 22.48, H 2.65, S 43.07.
Complex 8 is also sensitive to demethylation upon heat-
ing. Indeed, after heating an acetonitrile solution of 8 over-
night, NMR spectroscopy revealed the partial evolution of
the bis(thiolate) complex to the dithiolene complex [Pt(η2-
4
3
dppm)(dmit)] (δ = 47.0 ppm with JPt,P = 2429 Hz in the 1H (CDCl3, 298 K): δ = 2.68 (d, JP,H = 1.4, JPt,H = 14 Hz, 6 H,
31P{1H} NMR spectrum) and formation of Me2dmit (δ =
S–CH3), 2.08 (s, 6 H, P–CH2–), 1.19 (m, 9 H, CH2–CH3) ppm.
31P{1H} NMR (CDCl3, 298 K):
3348 Hz) ppm.
δ
=
16.5 (s, 1J
=
P
1
2.49 ppm in the H NMR spectrum).
195Pt,31
cis-[Pt(PEt3)2L]+ (4): Complex 2 (13.5 mg, 0.02 mmol), TlPF6
(9 mg, 0.026 mmol) and CDCl3 (0.5 mL) were mixed in a NMR
tube (Caution: Thallium and its compounds are extremely toxic and
should be handled with great care). The reaction was monitored by
31P{1H} and 1H NMR spectroscopy. After a few minutes the
Conclusions
We have shown that thiolate/thioether L coordinates to
diphosphane platinum(II) centres by a firm metal–thiolate
link and an incipient metal–thioether interaction in 31P{1H} NMR spectrum showed the quantitative transformation
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Platinum(II) Complexes Bearing a Thiolate/Thioether Ligand
4
of 2 into 4. 1H NMR (CDCl3, 298 K): δ = 2.95 (d, JP,H = 3.1,
[Pt(dppm)L2] (8): An MeOH (10 mL) solution of [Pt(dppm)Cl2]
(0.085 g, 0.13 mmol) and CsL (2 equiv., 0.090 g, 0.26 mmol) was
stirred 4 h. at 40 °C. After filtration, the solid was extracted into
CH2Cl2 (10 mL). Evaporation under reduced pressure afforded an
orange powder (60 mg, 46%). C33H28P2PtS10 (1002.24): calcd. C
3JPt,H = 33 Hz, 3 H, S–CH3), 2.16 (s, 12 H, P–CH2–), 1.20 (m, 18
H, CH2–CH3) ppm. 31P{1H} NMR (CDCl3, 298 K): δ = 13.5 (d,
2JP,P = 22, 1J
= 3048 Hz), 9.4 (d, JP,P = 22, 1J
=
2
195Pt,31
P
195Pt,31
P
2702 Hz) ppm.
1
39.54, H 2.82, S 31.99; found C 39.42; H 2.70, S 31.67. H NMR
[Pt(PEt3)2(dmit)] (5): Heating a solution of 1 (0.100 g, 0.12 mmol)
in acetonitrile (10 mL) to reflux overnight led to an equimolar mix-
ture of 5 and Me2dmit. A pure sample of 5 was synthesised accord-
ing the following procedure: equimolar quantities (0.5 mmol) of
cis-[Pt(PEt3)2Cl2] and Na2dmit[29] were heated to reflux in CH2Cl2
(20 mL) overnight under argon. After filtration, hexane was added
to the red solution, which resulted in the precipitation of 5 as a
red-brown powder (170 mg, 54%). C15H30P2PtS5 (627.76): calcd. C
(CDCl3, 298 K): δ = 7.75–7.47 (20 H, Ph), 4.41(m, 2 H, P–CH2–
P), 2.35 (s, 6 H, S–CH3) ppm. 31P{1H} NMR (CDCl3, 298 K): δ =
–48.1 (s, 1J
= 2585 Hz) ppm. IR (KBr): ν = 3053, 2963, 1435,
˜
195Pt,31
P
1261, 1099, 1063 (C=S), 1028 (C=S), 874, 800 cm–1.
[Pt(dppe)L2] (9): Complex 9 was prepared in an analogous manner
to
8 starting from [Pt(dppm)Cl2] and CsL (50% yield).
C34H30P2PtS10 (1016.27): calcd. C 40.18, H 2.98, S 31.55; found C
40.05, H 2.77, S 30.97. 1H NMR (CDCl3, 298 K): δ = 7.76–7.52
(20 H, Ph), 2.38 (m, 4 H, PCH2–CH2P), 2.26 (s, 6 H, S–CH3) ppm.
1
28.70, H 4.82, S 25.54; found C 28.91, H 4.89, S 25.02. H NMR
(CDCl3, 298 K): δ = 2.09 (12 H, P–CH2–), 1.18 (t, 18 H, CH2–
31P{1H} NMR (CDCl3, 298 K):
δ
=
47.0 (s, 1J
=
CH3) ppm. 31P{1H} NMR (CDCl3, 298 K): δ = 6.5 (s, 1J
195Pt,31
P
195Pt,31
P
2974 Hz) ppm. IR (KBr): ν = 2959, 2914, 1435, 1103, 1049 (C=S),
˜
= 2798 Hz) ppm. IR (KBr): ν = 2924, 2853, 1470, 1052 (C=S),
˜
1028 (C=S), 878, 818, 750, 715 cm–1.
1027(C=S) cm–1.
[Pt(PPh3)(η1-L)(η2-L)] (7): A CH2Cl2 (10 mL) solution of cis-
[Pt(PPh3)2Cl2] (0.126 g, 0.16 mmol) and CsL (2 equiv., 0.110 g,
0.32 mmol) was stirred at room temperature for 3 h. After fil-
tration, the solvent was removed under reduced pressure. The re-
sulting orange powder was washed with ethanol to afford a solid
(0.105 mg), which was identified as a mixture of 6[16] and 7. Com-
plexes 6 and 7 were separated by chromatography (SiO2, CHCl3),
Crystal Structure Determinations: Compounds 1 and 5: Stoe IPDS
diffractometer; data collection: Expose in IPDS (Stoe & Cie, 1999),
cell determination and refinement: Cell in IPDS (Stoe & Cie, 1999),
integration: Integrate in IPDS (Stoe & Cie, 1999); numerical ab-
sorption correction: Faceit in IPDS (Stoe & Cie, 1999). Com-
pounds 2, 3, 7 and 8: Bruker APEX diffractometer (D8 three-circle
goniometer) (Bruker AXS); data collection, cell determination and
refinement: Smart version 5.622 (Bruker AXS, 2011); integration:
SaintPlus version 6.02 (Bruker AXS, 1999); empirical absorption
correction: Sadabs version 2.01 (Bruker AXS, 1999).
and pure
7 (50 mg) was recovered in the first fraction.
C26H21PPtS10 (880.22): calcd. C 35.48, H 2.41, S 36.43; found C
35.71, H 2.69, S 35.87. 1H NMR (CDCl3, 320 K): δ = 7.70–7.44
(m, 15 H, Ph), 2.60 (3JPt,H = 15 Hz, 6 H, S–CH3) ppm. 31P{1H} A suitable crystal of each complex was mounted in an inert oil
1
195Pt,31
P
NMR (CDCl3, 298 K): δ = 17.3 (s, J
= 3585 Hz) ppm.
(perfluoropolyalkylether); the crystal structure determination was
Table 2. Crystallographic refinement data for 1, 2 and 3.
1
2
3
Formula
Formula weight
C20H36P2PtS10
854.12
C16H33ClP2PtS5
678.24
C14H21PPtS10
736.06
Temperature [K]
Wavelength [Å]
173(2)
0.71073
173(2)
0.71073
173(2)
0.71073
Crystal system
Space group
monoclinic
P1
monoclinic
P21/n
monoclinic
P21/c
¯
a [Å]
b [Å]
c [Å]
α [°]
8.6626(9),
10.5196(11)
10.8651(11)
61.1180(10)
87.101(2)
10.4688(9)
22.4622(10)
11.2344(7)
10.7909(6)
29.2394(11)
7.6003(2)
β [°]
108.792(8)
98.731(3)
γ [°]
69.5280(10)
803.70(14)
1
1.765
5.125
Volume [Å3]
2501.0(3)
4
1.801
6.264
2370.25(17)
4
2.096
6.287
592
Z
Density (calculated) [gcm–3]
Absorption coefficient [mm–1]
F(000)
424
1336
Crystal size [mm]
Theta range for data collection [°]
Index ranges
0.30ϫ0.30ϫ0.20
2.16 to 27.00
–11 Յ h Յ 11,
–13 Յ k Յ 13,
–13 Յ l Յ 13
19653
0.30ϫ0.20ϫ0.10
2.25 to 27.00
–13 Յ h Յ 13,
–28 Յ k Յ 28,
–14 Յ l Յ 14
17987
0.40ϫ0.20ϫ0.20
2.03 to 27.00
–12 Յ h Յ 13,
–36 Յ k Յ 37,
–9 Յ l Յ 9
23207
Reflections collected
Independent reflections
Refinement method
3506 [R(int) = 0.0295]
5421 [R(int) = 0.0627]
Full-matrix least-squares on F2
5421/0/233
5041 [R(int) = 0.0411]
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [IϾ2σ(I)]
R indices (all data)
3506/0/156
1.025
5041/0/240
1.013
0.990
R1 = 0.0123, wR2 = 0.0338 R1 = 0.0409, wR2 = 0.1063
R1 = 0.0123, wR2 = 0.0338 R1 = 0.0530, wR2 = 0.1094
0.925 and –0.883
R1 = 0.0272, wR2 = 0.0506
R1 = 0.0396, wR2 = 0.0522
0.988 and –2.435
Largest diff. peak and hole [eÅ–3]
4.170 and –1.734
Eur. J. Inorg. Chem. 2012, 282–291
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289

F. Guyon, M. Knorr, A. Garillon, C. Strohmann
FULL PAPER
Table 3. Crystallographic refinement data for 5, 7 and 8.
5
7
8
Formula
Formula weight
C15H30P2PtS5, CH2Cl2
712.65
C26H21PPtS10, 0.5 CHCl3
880.22
C33H28P2PtS10
1002.18
Temperature [K]
Wavelength [Å]
173(2)
0.71073
173(2)
0.71073
173(2)
0.71073
Crystal system
Space group
monoclinic
P21/n
monoclinic
P1
monoclinic
P1
¯
¯
a [Å]
b [Å]
c [Å]
α [°]
11.075(4)
17.921(6)
13.330(5)
13.3850(2)
13.8880(2)
19.6274(3)
90.5060(10)
7.9483(2)
11.3708(3)
20.6496(6)
103.175(2)
94.626(2)
β [°]
102.422(6)
97.8530(10)
γ [°]
113.727(2)
3300.63(9)
4
1.891
5.074
1836
91.375(2)
1809.51(8)
2
1.839
4.569
Volume [Å3]
2593.7(16)
4
1.832
6.168
1400
Z
Density (calculated) [gcm–3]
Absorption coefficient [mm–1]
F(000)
988
Crystal size [mm]
Theta range for data collection [°]
Index ranges
0.30ϫ0.30ϫ0.20
1.93 to 26.63
–13 Յ h Յ 13,
–22 Յ k Յ 22,
–16 Յ l Յ 16
47856
0.20ϫ0.20ϫ0.20
2.15 to 27.00
–17 Յ h Յ 17,
–17 Յ k Յ 17,
–25 Յ l Յ 25
140362
0.40ϫ0.20ϫ0.10
2.30 to 27.00
–10 Յ h Յ 10,
–14 Յ k Յ 14,
–26 Յ l Յ 26
26543
Reflections collected
Independent reflections
Refinement method
5394 [R(int) = 0.0552]
14385[R(int) = 0.0519]
Full-matrix least-squares on F2
14385/0/725
7854 [R(int) = 0.0382]
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [IϾ2σ(I)]
R indices (all data)
5394/0/241
1.070
R1 = 0.0378, wR2 = 0.1043
R1 = 0.0399, wR2 = 0.1057
2.454 and –1.240
7854/ 0/417
1.007
R1 = 0.0279, wR2 = 0.0593
R1 = 0.0366, wR2 = 0.0603
4.138 and –0.764
1.009
R1 = 0.0242, wR2 = 0.0567
R1 = 0.0357, wR2 = 0.0580
1.445 and –1.494
Largest diff. peak and hole [eÅ–3]
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Received: September 6, 2011
Published Online: December 7, 2011
Eur. J. Inorg. Chem. 2012, 282–291
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
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