Reaction of 3,3,5,5-Tetraphenyl-1,2,4-trithiolane with Pt 0(bisphosphane)(η2-nbe) complexes bearing bridged bisphosphane ligands with various bite angles

Article abstract of DOI:10.1002/ejic.200900121

A series of Pt⁰(η²-nbe) complexes [nbe = norbomene (bicyclo[2.2.1]hept-2-ene)] bearing bridged bisphosphane ligands with various bite angles (5a-c) was treated with 3,3,5,5-tetraphenyl-1,2,4- trithiolane (1) at 50 °C in a toluene sol

Full text of DOI:10.1002/ejic.200900121

FULL PAPER
DOI: 10.1002/ejic.200900121
Reaction of 3,3,5,5-Tetraphenyl-1,2,4-trithiolane with
Pt0(bisphosphane)(η2-nbe) Complexes Bearing Bridged Bisphosphane Ligands
with Various Bite Angles
Thomas Weisheit,[a] Holm Petzold,[b] Helmar Görls,[a] Grzegorz Mloston,[c] and
Wolfgang Weigand*[a]
Dedicated to Professor Juzo Nakayama on the occasion of his 65th birthday
Keywords: P ligands / S ligands / Rearrangement / Thiosulfines / Platinum
A series of Pt0(η2-nbe) complexes [nbe = norbornene (bicy-
clo[2.2.1]hept-2-ene)] bearing bridged bisphosphane ligands
with various bite angles (5a–c) was treated with 3,3,5,5-tet-
raphenyl-1,2,4-trithiolane (1) at 50 °C in a toluene solution.
These reactions resulted in the formation of the appropriate
dithiolato complexes 6a–c as well as the η2-thioketone com-
plexes 7a–c with respect to the 31P{1H} NMR spectroscopic
data. All isolated complexes were fully characterized. Kinetic
investigations using 31P{1H} NMR spectroscopy revealed
first-order kinetics in 1, pointing to the known cycloreversion
of 1 as the initial and rate-determining step for these reac-
tions. The formation of dithiolato complexes 6a–c suggests
1,3-dipolar electrocyclization of diphenylthiosulfine (3) to di-
phenyldithiirane (4) in solution. On the basis of these results
a plausible mechanism for the overall reaction is developed.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2009)
dithiirane 1-oxide as well as the corresponding dithiirane.[6]
Interestingly, it is still an open question if these dithiiranes
undergo thermal ring opening to thiosulfines, because inter-
ception with dipolarophiles failed.[6a]
Introduction
Although evidence for the existence of thiosulfines was
found nearly 30 years ago,[1] isolation of a stable member
of this class remains a continuous challenge. Huisgen and
Rapp used the thermal cycloreversion of 3,3,5,5-tet-
raphenyl-1,2,4-trithiolane (1) to generate diphenylthiosulf-
ine (3) and confirmed its existence by interception reactions
with diverse dipolarophiles.[2] In recent years, developments
in flash vacuum pyrolysis (FVP) allowed the study of thios-
ulfines in an argon matrix at 10 K[3] and provided more
insight into the rearrangement of thiosulfines[4] to di-
thiiranes or dithiocarboxylates,[3a,3c] as well as [1,4]-H shifts
to form vinyl disulfanyls.[3b]
Although experimental results and theoretical calcula-
tions suggest fast electrocyclization of thiosulfines to di-
thiiranes[5] (Scheme 1), there still is a lack of evidence for
this reaction at ambient temperature in solution. Nearly 15
years ago, Ishii et al. prepared the first stable and isolable
Scheme 1. Thermal cycloreversion of 1 and the proposed equilib-
rium between diphenylthiosulfine (3) and diphenyldithiirane (4).
The best proof for the presence of dithiiranes as reactive
intermediates is the interception with the Pt0(PPh3)2 com-
plex fragment to form stable dithiolato complexes.[5b,6e,6f,7]
In contrast, the oxidative addition of the Pt0(PPh3)2 com-
plex fragment into the sulfur–sulfur bond of 1,2,4-trithiol-
anes does not allow the generation of thiosulfines by cyclo-
reversion from this common type of precursor mole-
cule.[7a,8] In this context, a mechanism of the formation of
the dithiolato complex PtII(PPh3)2(S2CPh2) as well as the
η2-thioketone complex Pt0(PPh3)2(η2-S=CPh2) by reaction
of Pt0(PPh3)2(η2-C2H4) with 1 was proposed. After addition
of the Pt0 complex fragment to the sulfur–sulfur bond,
thiobenzophenone (2) is eliminated, which subsequently re-
acts with the excess amount of Pt0(PPh3)2(η2-C2H4) present
in the reaction mixture.[8a]
[a] Institut für Anorganische und Analytische Chemie, Friedrich-
Schiller-Universität,
07743 Jena, Germany
Fax: +49-3641-948102
E-mail: wolfgang.weigand@uni-jena.de
[b] TU Chemnitz, Institut für Chemie,
Straße der Nationen 62, 09111 Chemnitz, Germany
[c] University of Łódz´, Department of Organic and Applied
Chemistry,
Narutowicza 68, 90-136 Łódz´, Poland
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However, recently we showed that upon formal replace- 6a–c were obtained as yellow crystals by slow diffusion of
ment of the PPh3 ligands by bridged bisphosphanes, espe- pentane into these solutions. The molecular structures of 6b
cially those exhibiting a small bite angle at the metal center, and 6c were confirmed by X-ray structure determination
attack of the platinum complex fragment along the disulfide (Figures 1 and 2, respectively). Both complexes exhibit a
bond of tetrasubstituted 1,2,4-trithiolanes is hindered.[9] distorted square-planar geometry. The found bond lengths
Therefore, treatment of 1,2,4-trithiolanes with this type of and angles are comparable to those reported for similar di-
Pt0(bisphosphane) complex fragment should allow investi- thiolato complexes.[5b,7a]
gations of their thermal cycloreversion in solution at ambi-
ent or even elevated temperatures.
Here we report on the reaction of 3,3,5,5-tetraphenyl-
1,2,4-trithiolane (1) with a series of Pt0(bisphosphane)(η2-
nbe) complexes bearing bisphosphane ligands with various
bite angles (Scheme 2).
Figure 1. Molecular structure of 6b at 50% probability level. Hy-
drogen atoms and solvent molecules have been omitted for clarity.
The phenyl groups of the dppbe ligand are represented by their
ipso-carbon atoms. Selected bond lengths [Å] and angles [°]: Pt–P1
2.257(2), Pt–P2 2.2323(19), Pt–S1 2.324(2), Pt–S2 2.318(2), S1–C1
1.872(9), S2–C1 1.865(8), P1–Pt–P2 87.12(8), S1–Pt–S2 75.86(8),
P1–Pt–S1 102.56(8), P2–Pt–S2 94.57(8), S1–C1–S2 99.6(4).
Scheme 2. Nomenclature of the bidentate phosphanes used within
this contribution.
Results and Discussion
Despite the high stability of the Pt0(bisphosphane)(η2-
nbe) complexes, as a result of the relatively small bite angles
Figure 2. Molecular structure of 6c at 50% probability level. Hy-
of the bisphosphanes[10] and the steric shielding of the sul-
drogen atoms and solvent molecules have been omitted for clarity.
The phenyl groups of the dpp(o-xyl) ligand are represented by their
fur–sulfur bond in 1 they smoothly react in a toluene solu-
tion above 35 °C. Decolorization of the solutions to pale
yellow as well as the precipitation of a yellow solid indicates
the consumption of the Pt0 starting material and formation
ipso-carbon atoms. Selected bond lengths [Å] and angles [°]: Pt–P1
2.2624(12), Pt–P2 2.2613(13), Pt–S1 2.3173(13), Pt–S2 2.3149(12),
C1–S1 1.856(5), C1–S2 1.856(5), P1–Pt–P2 95.42(5), S1–Pt–S2
75.99(4), P1–Pt–S1 95.09(5), P2–Pt–S2 93.82(5), S1–C1–S2
100.4(2).
1
of new complexes. The typical JP,Pt values found in the
31P{1H} NMR spectra point to the formation of a 1:1 mix-
ture of the appropriate dithiolato complex 6 and η2-thio-
ketone complex 7 (Scheme 3).
The 31P{1H} NMR spectra of 6a–c show a singlet along
with 195Pt satellites, which confirms the symmetrical confor-
1
mation of these complexes in solution. The value of JP,Pt
increases with the P–Pt–P angle. Whereas complex 6a exhi-
1
bits a JP,Pt coupling constant of 2666 Hz, the value in-
creases to 2847 and 2931 Hz for 6b and 6c, respectively.
These values are in good agreement with the corresponding
P–Pt–P angle, enlarged from 87.12(8)° for 6b to 95.42(5)°
for 6c. A similar correlation concerning the 1JP,Pt values was
already reported for the corresponding Pt0(bisphos-
Scheme 3. Formation of dithiolato complexes 6a–c and η2-thio-
ketone complexes 7a–c [a: P = 1/2 dppn; b: P = 1/2 dppbe; c: P =
1/2 dpp(o-xyl)].
In order to get pure samples of dithiolato complexes 6a– phane)(η2-nbe) complexes.[9]
c, a solution of the corresponding complex 5 and 1 in tolu-
In order to prove the formation of complexes 7a–c in the
ene was stirred for 3 h at 50 °C, and the solvents were then reaction of 5a–c with 1, authentic samples of 7a–c were
evaporated to dryness. The residues were washed with di- synthesized independently from thiobenzophenone 2 and
ethyl ether and dissolved in thf. Pure dithiolato complexes 5a–c (Scheme 4).
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Reaction of 3,3,5,5-Tetraphenyl-1,2,4-trithiolane with Pt0 Complexes
Scheme 4. Syntheses of η2-thioketone complexes 7a–c [a: P = 1/2
dppn; b: P = 1/2 dppbe; c: P = 1/2 dpp(o-xyl)].
Diffusion of pentane into thf solutions of 7b and 7c
yielded crystals suitable for X-ray structure determination.
The constitution and purity of 7a–c were confirmed by the
molecular peaks in the mass spectra as well as the correct
elemental analysis. The molecular structures of 7b and 7c
are presented in Figures 3 and 4, respectively. For both
complexes the arrangement of the ligands around the plati-
num center is distorted square planar. The nonequivalent
Pt–P bond lengths in 7b and 7c can be explained by the
different trans influence of the sulfur and the carbon atom,
respectively, as reported for similar structures.[5b,7a,8b] The
side-on coordination of 2 to the Pt0(bisphosphane) moiety
is clearly visible. By virtue of π back donation, the C1–
S bonds are elongated in comparison to a uncoordinated
thiobenzophenone (2), exhibiting a sulfur–carbon bond
length of 1.64 Å.[11] In the 13C{1H} NMR spectra of 7a–c
the signal of the C=S group is remarkably shifted upfield
(81–86 ppm) relative to that of free 2 (δ = 238.5 ppm).[12]
These large shifts as well as the determined Pt–S, Pt–C1
and C1–S bond lengths identify complexes 7a–c as platina–
thiirane cycles rather than classical π complexes. The
31P{1H} NMR spectra of 7a–c reveal a typical AB spin sys-
tem pattern (two doublets with appropriate 195Pt satellites)
according to the unsymmetrical conformation of these com-
plexes. As a result of the different trans influence of the
sulfur and the carbon atom, the two coupling constants are
conspicuously different. Again, there is an obvious trend in
Figure 4. Molecular structure of 7c at 50% probability level. Hy-
drogen atoms and solvent molecules have been omitted for clarity.
The phenyl groups of the dpp(o-xyl) ligand are represented by their
ipso-carbon atoms. Selected bond lengths [Å] and angles [°]: Pt–P1
2.2475(13), Pt–P2 2.2733(11), Pt–S 2.2990(14), Pt–C1 2.157(5), C1–
S 1.787(5), P1–Pt–P2 102.58(5), S–Pt–C1 47.14(14), P1–Pt–C1
104.07(14), P2–Pt–S 106.21(5), C2–C1–C8 115.4(4).
On the one hand, the formation of complexes 6 and 7
could be reasonably explained by insertion of the Pt0 com-
plex fragment into the sulfur–sulfur bond of 1 followed by
expulsion of thiobenzophenone.[8a,8c] On the other hand,
however, the failed reaction of 5a with spirocyclohexyl-
1,2,4-trithiolane[9] suggests a different mechanism for the
reaction of Pt0 complexes bearing bisphosphanes with small
bite angles with 1,2,4-trithiolanes.
In order to gain more information on the reaction rate
and reaction order, we performed kinetic measurements by
using 31P{1H} NMR spectroscopy. In a first experiment,
we focused on Pt0(bisphosphane)(η2-nbe) complex 5a and
investigated the influence of the molar ratios on the rate
constant of its reaction with 1 (Table 1, Runs 1–3). The ob-
served rate constants of the consumption of 1 and 5a as
well as the corresponding molar concentration of 1 and 5a
are summarized in Table 1.
1
1
the JP,Pt coupling constants. The values of both JP,Pt in-
crease with the bite angle P–Pt–P [for 7b: P–Pt–P 87.35(7)°,
Table 1. Parameters concerning the kinetic measurements and the
observed rate constants for the reactions of 5a–c with 1.
1
1JP,Pt = 2909/4070 Hz; for 7c: P–Pt–P 102.58(5)°, JP,Pt
=
3062/4333 Hz].
Run
Pt0
[P2Pt(η2-
[1][a]
kobs (Pt0) kobs (1)[c]
[b]
nbe)][a]
1
2
3
4
5
5a 2.81ϫ10–2 1.42ϫ10–2 1.68ϫ10–3 1.72ϫ10–3
5a 2.80ϫ10–2 2.80ϫ10–2 3.26ϫ10–3 1.34ϫ10–3
5a 2.81ϫ10–2 5.59ϫ10–2 6.97ϫ10–3 1.27ϫ10–3
5b 2.80ϫ10–2 1.40ϫ10–2 2.05ϫ10–3 2.01ϫ10–3
5c
2.80ϫ10–2 1.43ϫ10–2 1.63ϫ10–3 1.61ϫ10–3
[a] Initial concentrations are given in molL–1. [b] Rate constants
[s–1] based on the consumption of 5a–c were calculated by using
the concentration of 5a–c obtained by 31P{1H} NMR spectroscopy.
[c] Rate constants [s–1] based on the consumption of 1 were deter-
mined by using the concentration of 1 calculated with Equation (1).
In order to ensure a good signal-to-noise ratio and a
maintainable accumulation recording time of the 31P{1H}
NMR spectra, the concentration of 5a–c had approximately
the same value for each run.
The obtained results showed that the rate of consump-
tion of 5a is linearly dependent on the concentration of 1
when using the same initial concentration of 5a in each
Figure 3. Molecular structure of 7b at 50% probability level. Hy-
drogen atoms and solvent molecules have been omitted for clarity.
The phenyl groups of the dppbe ligand are represented by their
ipso-carbon atoms. Selected bond lengths [Å] and angles [°]: Pt–P1
2.2492(18), Pt–P2 2.260(2), Pt–S 2.295(2), Pt–C1 2.156(7), C1–S
1.815(11), P1–Pt–P2 87.34(7), S–Pt–C1 48.0(3), P1–Pt–C1 113.2(3),
P2–Pt–S 111.36(7), C2–C1–C8 116.4(7).
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T. Weisheit, H. Petzold, H. Görls, G. Mloston, W. Weigand
FULL PAPER
case. No other signals than that due to 5a, 6a, and 7a were
detected in the 31P{1H} NMR spectra; 6a and 7a were
found to be formed side by side in a constant ratio of 1:1
during the course of the experiment. An appropriate plot
of the natural logarithm of the relative concentration of 1,
calculated on the basis of the concentration of 5a [Equa-
tion (1)], over time gave nearly linear slopes (Figure 5) and
comparable rate constants.
[1]t = [1]0 – 1/2·([5]0 – [5]t)
(1)
Scheme 5. Postulated mechanism of the formation of dithiolato
complexes 6 and η2-thioketone complexes 7 in the reaction of 1
with 5a–c [a: P = 1/2 dppn; b: P = 1/2 dppbe; c: P = 1/2 dpp-
(o-xyl)].
Scheme 6. Comparison of the trapping reactions of diphenylthio-
sulfine (3) and diphenyldithiirane (4) with DMAD and a (bisphos-
phane)Pt0 complex fragment, respectively.
Conclusions
In summary, the current study shows that 3,3,5,5-tet-
raphenyl-1,2,4-trithiolane (1) is reactive towards Pt0 com-
plex fragments containing bridged bisphosphane ligands at
elevated temperatures, yielding equimolar amounts of di-
thiolato complexes of type 6 and η2-thioketone complexes
of type 7. The appropriate Pt0(bisphosphane)(η2-nbe) com-
plexes turned out to be a very efficient source of the re-
quested Pt0 moiety. By means of kinetic measurements
based on 31P{1H} NMR spectroscopy, the initial step of
these reactions was determined to be the thermal cyclore-
version of 1. Thus, a convincing reaction mechanism could
be formulated (Scheme 5). This, as well as the isolation of
the corresponding interception products, should verify the
pathway of the cleavage of 1 into a thioketone and the cor-
responding thiosulfine. Furthermore the formation of dithi-
olato complexes 6 confirms the proposed rearrangement of
the in situ generated thiosulfine into the appropriate dithiir-
ane and gives unambiguous evidence for an equilibrium be-
tween thiosulfine 3 and dithiirane 4 in solutions at room
temperature.
Figure 5. Plot of the natural logarithm of the relative concentration
of 1 vs. the time followed by a linear regression of each data set in
order to calculate the rate constants based on the concentration of
1.
These data agree well with first-order kinetics in 1; hence,
the cycloreversion of 1 is the initial and rate-determining
step of the overall reaction. As a consequence, the reaction
rate should be independent of the nature of the Pt0 complex
5 as well as its concentration, because 5 only serves as trap-
ping agent and is not involved in the rate-determining step.
Indeed, reaction rate constants determined for the reactions
of 1 with 5b and 5c are approximately the same with respect
to the rather rough method with relatively large error
(Table 1, Runs 4 and 5).
These results allow one to formulate a new reaction
mechanism (Scheme 5) in which the first step is the cyclore-
version of 1,2,4-trithiolane (1) into thiobenzophenone (2)
and diphenylthiosulfine (3). The latter rearranges to di-
phenyldithiirane (4), which reacts with 5 by insertion into
the sulfur–sulfur bond.
Taking into account that 3 was successfully trapped by
Huisgen and Rapp in a similar reaction with DMAD (di-
methyl acetylenedicarboxylate),[2] it is very likely that 3 ex-
ists in an equilibrium with 4 (Scheme 6).
As 4 is more stable then 3, 4 is probably the major com-
ponent of that equilibrium system. However, diphenyldi-
thiirane (4) is unreactive towards DMAD, and for this
reason diphenylthiosulfine (3) is selectively trapped with
DMAD.
Experimental Section
General Procedures: Unless otherwise stated, all reactions were car-
ried out under an atmosphere of argon by using standard Schlenk
techniques. Used solvents were distilled from sodium and benzo-
phenone prior use. Thiobenzophenone (2),[13] 3,3,5,5-tetraphenyl-
1,2,4-trithiolane (1),[2b] and 5a–c[9] were prepared according to lit-
1
erature procedures. H, 13C{1H}, and 31P{1H} NMR spectra were
recorded with Bruker Avance 400 or Bruker Avance 200 spectrome-
1
ters at 27 °C. H NMR spectra were calibrated by using the signal
of the residual non-deuterated solvent, whereas 13C{1H} NMR
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Reaction of 3,3,5,5-Tetraphenyl-1,2,4-trithiolane with Pt0 Complexes
spectra were measured by using the signal of the solvent as internal
standard. 31P{1H} NMR spectra were determined by using 85%
1637 (m), 1587 (m), 1483 (s), 1435 (s), 1099 (s), 746 (m), 694 (vs),
553 (vs), 529 (vs), 506 (s) cm–1. MS (DEI): m/z = 839 [M]+, 641
[(dppbe)Pt]+, 563 [(dppbe)Pt – Ph]+, 485 [(dppbe)Pt – 2Ph]+.
C43H34P2PtS·0.33toluene (870.54): calcd. C 62.55, H 4.25, S 3.68;
found C 62.27, H 3.95, S 3.69.
1
H3PO4 as external standard. Assignments of the H and 13C{1H}
NMR signals were confirmed by two-dimensional NMR methods
1
1
(1H–1H COSY, H–13C HSQC, and H–13C HMBC NMR). Infra-
red spectra were taken with a Perkin–Elmer System 2000 FTIR
spectrometer. Mass spectra were obtained by using a Finnigan Mat
SSQ 710 mass spectrometer. Elemental analyses were performed
with a Vario EL III CHNS (Elementaranalysen GmbH Hanau)
as single determinations. Melting points were determined with an
Axiolab microscope with a TMHS 600 heating plate and are uncor-
rected.
7c: Compound 5c (121 mg, 0.158 mmol) was treated with 2 (34 mg,
0.171 mmol) to give 7c (65 mg, 0.075 mmol, 47%) as a pale yellow
1
solid. M.p. 145 °C. H NMR (400 MHz, CD2Cl2, 27 °C): δ = 7.78
[m, 4 H, o-C6H5 of dpp(o-xyl)], 7.44 [m, 6 H, m-C6H5 and p-C6H5
of dpp(o-xyl)], 7.24 [m, 2 H, p-C6H5 of dpp(o-xyl)], 7.16 [m, 4 H,
o-C6H5 of dpp(o-xyl)], 7.06 [m, 4 H, m-C6H5 of dpp(o-xyl)], 6.97
[m, 4 H, m-C6H5 of S=C(Ph)2], 6.82 [m, 2 H, m-C6H4 of dpp-
(o-xyl)], 6.77 [m, 6 H, o-C6H5 and p-C6H5 of S=C(Ph)2], 6.34 [m,
1 H, o-C6H4 of dpp(o-xyl)], 6.26 [m, 1 H, o-C6H4 of dpp(o-xyl)],
4.02 (m, 4 H, PCH2) ppm. 13C{1H} NMR (100 MHz, CD2Cl2,
General Procedure for the Syntheses of Pt0(bisphosphane)(η2-thio-
benzophenone) Complexes (7a–c): The appropriate Pt0(bisphos-
phane)(η2-nbe) complex 5 (1 equiv.) was dissolved in toluene
(15 mL) and 2 (1.1 equiv.) dissolved in toluene (5 mL) was added 27 °C): δ = 149.7 [m, ipso-C6H5 of S=C(Ph)2], 135.3 [m, ipso-C6H5
dropwise with stirring. The color of the red (5a) or yellow (5b, 5c)
solution rapidly turned light green. The resulting solution was
stirred for an additional 3 h. The solvent was removed in vacuo,
and the residue was washed several times with diethyl ether to give
the thioketone complexes in satisfying purity.
of dpp(o-xyl)] 133.9–133.0 [m, ipso-C6H5, o-C6H5 and ipso-C6H4
of dpp(o-xyl)], 131.2 [m, o-C6H4 of dpp(o-xyl)], 130.6 [s, p-C6H5 of
dpp(o-xyl)], 129.9 [m, p-C6H5 of dpp(o-xyl) and m-C6H5 of
S=C(Ph)2], 128.7–128.1 [m, m-C6H5 of dpp(o-xyl)], 126.8 [m, m-
C6H4 of dpp(o-xyl) and o-C6H5 of S=C(Ph)2], 124.1 [s, p-C6H5 of
S=C(Ph)2], 85.7 [s, S=C(Ph)2], 40.1–36.9 (m, PCH2) ppm. 31P{1H}
NMR (81 MHz, C6D6, 27 °C): δ = 10.4 (d with 195Pt satellites, 1JP,Pt
7a: Compound 5a (109 mg, 0.139 mmol) was treated with 2 (31 mg,
0.156 mmol) to give 7a (80 mg, 0.090 mmol, 65%) as a yellow solid.
2
1
= 4333 Hz, JP,P = 4.3 Hz), 8.7 (d with 195Pt satellites, JP,Pt
=
1
M.p. 280 °C (decomp.). H NMR (400 MHz, CD2Cl2, 27 °C): δ =
2
3062 Hz, JP,P = 4.3 Hz) ppm. IR (KBr): ν = 3052 (m), 1625 (m),
˜
8.12 (m, 2 H, 4-H and 5-H of dppn), 7.50–7.40 (m, 4 H, 2-H, 3-H,
6-H, and 7-H of dppn), 7.24–7.12 [m, 14 H, o-C6H5, m-C6H5, and
p-C6H5 of dppn and m-C6H5 of S=C(Ph)2], 7.08 (m, 2 H, p-C6H5
1588 (m), 1483 (s), 1435 (vs), 1099 (s), 769 (s), 742 (s), 695 (vs),
505 (vs) cm–1. MS (DEI): m/z = 867 [M]+, 669 [{dpp(o-xyl)}Pt]+,
588 [{dpp(o-xyl)}Pt – Ph]+, 512 [{dpp(o-xyl)}Pt – 2Ph]+, 434
[{dpp(o-xyl)}Pt – 3Ph]+. C45H38P2PtS (867.87): calcd. C 62.28, H
4.41, S 3.69; found C 62.41, H 3.98, S 3.38.
3
of dppn), 7.00 [t, JH,H = 7.6 Hz, 4 H, o-C6H5 of S=C(Ph)2], 6.93
[m, 4 H, p-C6H5 of S=C(Ph)2], 6.81 (m, 4 H, m-C6H5 of dppn),
6.50 (m, 4 H, o-C6H5 of dppn) ppm. 13C{1H} NMR (100 MHz,
CD2Cl2, 27 °C): δ = 150.7 [m, ipso-C6H5 of S=C(Ph)2], 137.5 (m,
C-1 and C-8 of dppn), 134.5–134.0 (m, C-8a and o-C6H5 of dppn),
133.7–133.4 (m, C-4, C-5, and o-C6H5 of dppn), 130.3 (s, p-C6H5
General Procedure for the Syntheses of PtII(bisphosphane)(diphenyl-
methanedithiolato) Complexes (6a–c): The appropriate Pt0(bisphos-
phane)(η2-nbe) complex 5 (1 equiv.) was dissolved in toluene
of dppn), 133.0 (m, ipso-C6H5 of dppn), 130.0–129.8 [m, p-C6H5 (30 mL) and 1 was added stoichiometrically. The solution was
of dppn and m-C6H5 of S=C(Ph)2], 128.5 (m, m-C6H5 of dppn), stirred for 3 h at 50 °C. After cooling, the solvent was removed in
127.8 (m, m-C6H5 of dppn), 127.0 [s, o-C6H5 of S=C(Ph)2], 125.7 vacuo and a green-blue mixture consisting of thioketone complex,
(m, C-2, C-3, C-6, C-7, and C-4a of dppn), 124.0 [s, p-C6H5 of dithiolato complex, and 2 was obtained. After several washings
S=C(Ph)2], 82.8 [s, S=C(Ph)2] ppm. 31P{1H} NMR (81 MHz,
C6D6, 27 °C): δ = 12.7 (d with 195Pt satellites, 1JP,Pt = 2739 Hz, 2JP,P
with diethyl ether the yellow solid was dissolved in a small amount
of thf. Pentane was allowed to diffuse into the solution to give
yellow crystals. After two additional crystallization steps pure dithi-
olato complexes were obtained.
1
2
= 22.4 Hz), 10.3 (d with 195Pt satellites, JP,Pt = 3900 Hz, JP,P
=
22.4 Hz) ppm. IR (KBr): ν = 3052 (m), 1625 (m), 1588 (m), 1482
˜
(s), 1435 (vs), 1095 (s), 770 (s), 745 (s), 694 (vs), 590 (vs), 523 (vs),
499 (vs) cm–1. MS (DEI): m/z = 890 [M]+, 692 [(dppn)Pt]+.
C47H36P2PtS (889.88): calcd. C 63.44, H 4.08, S 3.60; found C
64.17, H 3.55, S 3.57.
6a: Compound 5a (147 mg, 0.187 mmol) was treated with 1 (80 mg,
0.187 mmol) to give 6a (30 mg, 0.033 mmol, 18%) as pale yellow
needles. M.p. 280 °C (decomp.). 1H NMR (400 MHz, CD2Cl2,
27 °C): δ = 8.18 (m, 2 H, 4-H and 5-H of dppn), 7.62 [m, 4 H, o-
C6H5 of S2C(Ph)2], 7.49 (m, 2 H, 3-H and 6-H of dppn), 7.43 (m,
2 H, 2-H and 7-H of dppn), 7.32–7.16 [m, 24 H, o-C6H5, m-C6H5,
and p-C6H5 of dppn and m-C6H5 of S2C(Ph)2], 7.09 [m, 2 H, p-
7b: Compound 5b (140 mg, 0.190 mmol) was treated with 2 (41 mg,
0.207 mmol) to give 7b (110 mg, 0.131 mmol, 69%) as yellow solid.
1
M.p. 160 °C (decomp.). H NMR (400 MHz, CD2Cl2, 27 °C): δ =
7.75 (m, 2 H, o-C6H4 of dppbe), 7.64 (m, 4 H, o-C6H5 of dppbe), C6H5 of S2C(Ph)2] ppm. 13C{1H} NMR (100 MHz, CD2Cl2,
7.48 (m, 2 H, m-C6H4 of dppbe), 7.41 (m, 6 H, m-C6H5 and p-
C6H5 of dppbe), 7.29–7.12 [m, 14 H, m-C6H5 and o-C6H5 of dppbe
and m-C6H5 of S=C(Ph)2], 6.86 [m, 6 H, o-C6H5 and p-C6H5 of
S=C(Ph)2] ppm. 13C{1H} NMR (100 MHz, CD2Cl2, 27 °C): δ =
151.0 [m, ipso-C6H5 of S=C(Ph)2], 146.5 (m, ipso-C6H4 of dppbe),
27 °C): δ = 155.6 [m, ipso-C6H5 of S2C(Ph)2], 138.9 (m, C-8a of
dppn), 137.6 (m, C-2 and C-7 of dppn), 135.8 (m, C-1 and C-8 of
dppn), 134.3 (m, C-4 and C-5 of dppn), 134.1 (t, 2JC,P = 5.7 Hz, o-
C6H5 of dppn), 130.9 (s, p-C6H5 of dppn), 129.9 (m, ipso-C6H5 of
dppn), 128.4 (t, 3JC,P = 5.6 Hz, m-C6H5 of dppn), 127.3 [s, m-C6H5
133.6–133.1 (m, m-C6H4, o-C6H5 and ipso-C6H5 of dppbe), 131.9– of S2C(Ph)2], 126.8 [s, o-C6H5 of S2C(Ph)2], 125.8 (m, C-3 and C-
131.5 (m, o-C6H4 of dppbe), 130.8 (s, p-C6H5 of dppbe), 130.2 (m,
m-C6H5 of dppbe), 129.0 (m, m-C6H5 of dppbe), 128.6 [m, o-C6H5
6 of dppn), 125.5 [s, p-C6H5 of S2C(Ph)2], 121.7 (m, C-4a of dppn),
73.8 [m, S2C(Ph)2] ppm. 31P{1H} NMR (81 MHz, C6D6, 27 °C): δ
1
or m-C6H5 of S=C(Ph)2], 127.7 [s, o-C6H5 or m-C6H5 of = 13.4 (s with 195Pt satellites, JP,Pt = 2666 Hz, P2PtS2) ppm. IR
S=C(Ph)2], 124.1 [s, p-C6H5 of S=C(Ph)2], 80.8 [s, S=C(Ph)2] ppm.
(KBr): ν = 3053 (m), 1625 (m), 1482 (m), 1436 (s), 1096 (s), 771
˜
31P{1H} NMR (81 MHz, C6D6, 27 °C): δ = 49.7 (d with 195Pt satel-
(m), 744 (m), 693 (vs), 592 (vs), 527 (vs), 503 (vs) cm–1. MS (DEI):
m/z = 922 [M]+, 755 [(dppn)PtS2]+, 723 [(dppn)PtS]+, 645 [(dppn)
PtS – Ph]+, 535 [(dppn)Pt – 2Ph]+, 459 [(dppn)Pt – 3Ph]+, 427 [M –
lites, 1JP,Pt = 2909 Hz, 2JP,P = 27.6 Hz), 42.4 (d with 195Pt satellites,
2
1JP,Pt = 4070 Hz, JP,P = 27.6 Hz) ppm. IR (KBr): ν = 3052 (m),
˜
Eur. J. Inorg. Chem. 2009, 3545–3551
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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3549

T. Weisheit, H. Petzold, H. Görls, G. Mloston, W. Weigand
(dppn)]+. C47H36P2PtS2 (921.94): calcd. C 61.23, H 3.94, S 6.96; [s, m-C6H4 of dpp(o-xyl)], 127.3 [s, m-C6H5 of S2C(Ph)2], 126.6 [s,
FULL PAPER
found C 61.05, H 3.81, S 6.75.
o-C6H5 of S2C(Ph)2], 125.5 [s, p-C6H5 of S2C(Ph)2], 75.5 [m,
S2C(Ph)2], 36.6 (m, PCH2) ppm. 31P{1H} NMR (81 MHz, C6D6,
6b: Compound 5b (140 mg, 0.190 mmol) was treated with 1 (80 mg,
0.187 mmol) to give 6b (30 mg, 0.035 mmol, 18%) as yellow crys-
1
27 °C): δ = 5.1 (s with 195Pt satellites, JP,Pt = 2931 Hz, P2PtS2)
ppm. IR (KBr): ν = 3053 (m), 1618 (w), 1591 (w), 1483 (s), 1435
˜
1
tals. M.p. 238 °C (decomp.). H NMR (400 MHz, CD2Cl2, 27 °C):
(vs), 1310 (w), 1184 (w), 1099 (s), 1073 (w), 1029 (w), 865 (m), 836
(m), 771 (m), 743 (s), 693 (vs), 505 (vs) cm–1. MS (DEI): m/z = 899
[M]+, 733 [{dpp(o-xyl)}PtS2]+, 700 [{dpp(o-xyl)}PtS]+, 591
[{dpp(o-xyl)}Pt – Ph]+. C45H38P2PtS2 (921.94): calcd. C 60.06, H
4.26, S 7.13; found C 59.79, H 4.10, S 7.34.
δ = 7.71 (m, 2 H, o-C6H4 of dppbe), 7.68–7.63 [m, 12 H, o-C6H5
of dppbe and o-C6H5 of S2C(Ph)2], 7.56 (m, 2 H, m-C6H4 of
dppbe), 7.48–7.39 (m, 12 H, m-C6H5 and p-C6H5 of dppbe), 7.17
[m, 4 H, m-C6H5 of S2C(Ph)2], 7.07 [m, 2 H, p-C6H5 of S2C(Ph)2]
ppm. 13C{1H} NMR (100 MHz, CD2Cl2, 27 °C): δ = 155.5 [s, ipso-
C6H5 of S2C(Ph)2], 142.5 (m, ipso-C6H4 of dppbe), 134.0 (m, o-
Kinetic Measurements: The kinetics of the reactions of 1 with the
2
C6H4 of dppbe), 133.6 (t, JC,P = 6.0 Hz, o-C6H5 of dppbe), 132.4
Pt0(bisphosphane)(η2-nbe) complexes
5 were investigated by
(m, m-C6H4 of dppbe), 131.5 (s, p-C6H5 of dppbe), 130.5 (m, ipso- 31P{1H} NMR spectroscopy. The appropriate Pt0(bisphos-
C6H5 of dppbe), 129.0 (t, 3JC,P = 5.6 Hz, m-C6H5 of dppbe), 127.3
phane)(η2-nbe) complex 5a–c (ca. 0.021 mmol) and triphenylphos-
[s, m-C6H5 of S2C(Ph)2], 126.5 [s, o-C6H5 of S2C(Ph)2], 125.6 [s, p- phane oxide (internal standard, 0.021 mmol) were dissolved in [D6]-
C6H5 of S2C(Ph)2], 77.8 [s, S2C(Ph)2] ppm. 31P{1H} NMR
benzene (0.75 mL) and 1 was added in the described amounts
(Table 1). The solution was transferred into a NMR tube and a
31P{1H} NMR spectrum was measured every 9 min with an overall
1
(81 MHz, C6D6, 27 °C): δ = 44.1 (s with 195Pt satellites, JP,Pt
=
2847 Hz, P PtS ) ppm. IR (KBr): ν = 3052 (m), 1636 (m), 1482
˜
2
2
(m), 1435 (s), 1099 (s), 748 (m), 694 (vs), 672 (m), 559 (vs), 533 accumulation time of 5.5 min to monitor the reaction progress. To
(vs), 505 (s) cm–1. MS (DEI): m/z = 871 [M]+, 838 [M – S]+, 705
[(dppbe)PtS2]+, 673 [(dppbe)PtS]+, 563 [(dppbe)Pt – Ph]+, 486
[(dppbe)Pt – 2Ph]+. C43H34P2PtS2 (871.90): calcd. C 59.23, H 3.93,
S 7.36; found C 59.12, H 4.43, S 6.83.
determine the reaction rate constant, the signals of the Pt0 starting
material and those of triphenylphosphane oxide were integrated by
using the program “MesTreC 4.7.0”. The integrals of the Pt0(bis-
phosphane)(η2-nbe) complexes were divided by the ones of the in-
ternal standard to obtain a term for the concentration of 5 at every
measuring point. These values were transferred into the term ln([5]0/
[5]t), where [5]0 is the initial concentration of 5. Plotting ln([5]0/
[5]t) vs. time, followed by a linear fit of each data set, gave the
appropriate reaction rate constant for a reaction of first-order ki-
netics based on the concentration of 5. The rate constants based
on the concentration of 1 were determined by using the concentra-
tions of 1, calculated with Equation (1). Plotting ln([1]0/[1]t) vs.
time and a subsequent linear regression revealed the requested rate
constants.
6c: Compound 5c (146 mg, 0.191 mmol) was treated with 1 (84 mg,
0.196 mmol) to give 6c (45 mg, 0.050 mmol, 26%) as yellow crys-
tals. M.p. 271 °C. 1H NMR (400 MHz, CD2Cl2, 27 °C): δ = 7.72
[m, 8 H, o-C6H5 of dpp(o-xyl)], 7.49–7.38 [m, 16 H, m-C6H5 and
p-C6H5 of dpp(o-xyl) and o-C6H5 of S2C(Ph)2], 7.11 [m, 4 H, m-
C6H5 of S2C(Ph)2], 7.06 [m, 4 H, m-C6H4 of dpp(o-xyl) and p-C6H5
of S2C(Ph)2], 6.57 [m, 2 H, o-C6H4 of dpp(o-xyl)], 3.94 (m, 4 H,
PCH2) ppm. 13C{1H} NMR (50 MHz, CD2Cl2, 27 °C): δ = 155.4
2
[s, ipso-C6H5 of S2C(Ph)2], 134.1 [t, JC,P = 5.3 Hz, o-C6H5 of
dpp(o-xyl)], 133.5 [s, ipso-C6H4 of dpp(o-xyl)], 132.0 [m, ipso-C6H5
of dpp(o-xyl)], 131.5 (s, o-C6H4 of dppbe), 131.2 [s, p-C6H5 of
dpp(o-xyl)], 128.4 [t, JC,P = 5.2 Hz, m-C6H5 of dpp(o-xyl)], 127.6 compounds were collected with
X-ray Crystal Structure Determinations: The intensity data for the
3
a
Nonius KappaCCD dif-
Table 2. Crystal data and refinement details for the X-ray structure determinations.
6b
6c
7b
7c
Formula
C43H34P2PtS2·0.5C6H6
910.91
–90(2)
monoclinic
P21/n
10.0310(4)
24.5801(12)
15.1680(5)
90
93.864(3)
90
3731.4(3)
4
1.621
39.92
C45H38P2PtS2·0.75C4H8O C43H34P2PtS·C4H8O
C45H38P2PtS·0.5C5H12
903.92
–90(2)
monoclinic
P21/n
12.1270(3)
13.3260(4)
26.8843(6)
90
93.836(2)
90
4334.89(19)
4
1.385
33.89
Mol. mass [gmol–1]
T [°C]
953.98
–90(2)
triclinic
911.90
–90(2)
monoclinic
P21
Crystal system
Space group
a [Å]
b [Å]
c [Å]
α [°]
β [°]
¯
P1
12.3635(4)
14.2706(3)
15.2932(5)
91.670(2)
110.584(1)
110.402(2)
2331.9(1)
2
9.7461(4)
16.5291(6)
12.0115(5)
90
94.828(2)
90
1928.12(13)
2
1.571
γ [°]
V [Å3]
Z
ρ [gcm–3]
1.359
µ [cm–1]
31.98
38.12
Measured data
Data with IϾ2σ(I)
Unique data/Rint
wR2 (all data, on F2)[a]
R1 [IϾ2σ(I)][a]
s[b]
24191
5528
8455/0.0867
0.1445
0.0564
1.023
1.526/–3.182
17022
8523
10608/0.0353
0.1115
0.0444
1.034
1.265/–1.015
13040
6845
22328
7882
9469/0.0428
0.1047
0.0399
1.064
1.547/–1.553
8027/0.0524
0.0955
0.0413
0.971
1.580/–1.352
0.009(8)
Res. dens. [eÅ–3]
Flack parameter
[a] Definition of the R indices: R1 = (Σ||Fo| – |Fc||)/Σ|Fo|, wR2 = {Σ[w(Fo – Fc ) ]/Σ[w(Fo2)2]}1/2 with w–1 = σ2(Fo2) + (aP)2. [b] s =
2
2 2
{Σ[w(Fo – Fc ) ]/(No – Np)}1/2
.
2
2 2
3550
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Eur. J. Inorg. Chem. 2009, 3545–3551

Reaction of 3,3,5,5-Tetraphenyl-1,2,4-trithiolane with Pt0 Complexes
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2
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Acknowledgments
We thank A. Blayer and Dr. M. Friedrich for recording the 31P{1H}
NMR spectra related with the kinetic investigations. G. M. ac-
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Łódz´ (Grant # 505/712).
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Received: February 4, 2009
Published Online: March 31, 2009
Eur. J. Inorg. Chem. 2009, 3545–3551
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
3551