Cis- and trans-influences in [PtCl2(SPh2)2]

Article abstract of DOI:10.1107/S010827010100960X

Both cis- and trans-dichlorobis(diphenyl sulphide)platinum(II), [PtCl₂(C₁₂H₁₀S)₂], crystallize as mononuclear pseudo-square-planar complexes. In the cis compound, the Pt-Cl distances are 2.295 (2) and 2.319 (2) A, and the Pt-S distances are 2.280 (2) and 2.283 (2) A. In the trans compound, Pt is located on a centre of inversion and the Pt-Cl and Pt-S distances are 2.2786 (15) and 2.3002 (12) A, respectively.

Full text of DOI:10.1107/S010827010100960X

metal-organic compounds
Ê
[ 0.0652 (11) A]. The closest non-bonding contact to Pt is
Ê
intramolecular to H226 at a distance of 2.92 A, where H226 is
Acta Crystallographica Section C
Crystal Structure
Communications
approximately situated at an octahedral position of the coor-
dination sphere of platinum. On the other side of the coor-
dination plane, the closest contact in the octahedral position is
intermolecular to H116 at (2 x, 1 y, z) at a distance of
ISSN 0108-2701
Ê
Cis- and trans-influences in
[PtCl2(SPh2)2]
3.43 A, too long to be a PtÁ Á ÁH interaction. The two closest
1
Ê
Cl1Á Á ÁH interactions are 2.84 and 2.97 A to H113 at (2 x,
12 + y, z) and H224 at ( 12 + x, y,
z), respectively. The
1
2Ê
closest Cl2Á Á ÁH interaction is 2.93 A to H225 at ( 12 + x, y,
Ê
1
2
Maria H. Johansson,* Ake Oskarsson, Karin Lovqvist,
È
z). The SÐPtÐSÐC torsion angles show that for each
Fotini Kiriakidou and Pramesh Kapoor²
ligand one SÐC bond is fairly close to the coordination plane,
while the other SÐC bonds are close to being perpendicular to
this plane (Table 1).
Inorganic Chemistry 1, University of Lund, Box 124, S-221 00 Lund, Sweden
Correspondence e-mail: maria.johansson@inorg.lu.se
In trans-[PtCl2(SPh2)2] (Fig. 2), the coordination is pseudo-
square planar, with Pt at a centre of inversion and bond angles
of 84.80 (5) and 95.20 (5)ꢀ around platinum. Atoms H112 are
located in an approximate octahedral site on both sides of the
Received 27 April 2001
Accepted 7 July 2001
Both cis- and trans-dichlorobis(diphenyl sul®de)platinum(II),
[PtCl2(C12H10S)2], crystallize as mononuclear pseudo-square-
planar complexes. In the cis compound, the PtÐCl distances
Ê
platinum, at a distance of 2.90 A, which is the closest non-
bonding contact (intramolecular) with platinum. The closest
non-bonding interaction to chloride is intermolecular to H114
Ê
at (1 + x, 12 y, 2 + z), at a distance of 2.73 A. The ClÐPtÐSÐ
C torsion angles show that one SÐC bond in the ligand is
fairly close to the coordination plane, while the other SÐC
bonds are close to being perpendicular to this plane (Table 2).
The Cambridge Structural Database (CSD; Allen &
Kennard, 1993) has been searched for compounds of the types
[PtCl2R2], [PtS4]2+ and [PtCl4]2 , where R represents a ligand
with a sulfur-donor atom connected to two C atoms. 31 cis- and
seven trans-[PtCl2R2] examples were found. From the CSD
are 2.295 (2) and 2.319 (2) A, and the PtÐS distances are
1
Ê
Ê
2.280 (2) and 2.283 (2) A. In the trans compound, Pt is located
on a centre of inversion and the PtÐCl and PtÐS distances
Ê
are 2.2786 (15) and 2.3002 (12) A, respectively.
Comment
In square-planar platinum(II) complexes, the trans-in¯uence
is a well known phenomenon which has been widely studied
for a large number of complexes, such as cis/trans-
[PtCl2(dms)2] (dms is dimethyl sul®de; Horn et al., 1990;
Johansson et al., 2001), cis-[PtCl2(dmso)2] (dmso is diemethyl
sulfoxide; Melanson & Rochon, 1975; Shibaeva, 1983) and cis/
trans-[PtCl2(tioxane)2] (Bugarcic et al., 1993). The trans-
in¯uence is larger for thioether sulfur than for chloride, but
the substituents on the S atom are expected to modulate the
in¯uence. In light of this, we have investigated the structures
of cis- and trans-dichlorobis(diphenyl sul®de)platinum(II), (I)
and (II), respectively.
Ê
search, a mean value of 2.319 (12) A was calculated for the
distances in ten [PtS4]2+ complexes (no chelating ligands) and
this value may be used as a reference value for a discussion of
the cis/trans in¯uence. The cis-[PtCl2R2] compounds have a
Ê
mean PtÐS distance of 2.24 (2) A (62 distances), while the
Ê
similar trans compounds have a mean of 2.301 (9) A (14
In cis-[PtCl2(SPh2)2] (Fig. 1), the coordination around Pt is
distorted square planar, with angles ranging from 83.68 (7) to
93.06 (7)ꢀ. The r.m.s. deviation from the Cl2PtS2 plane is
Ê
0.0550 A, where S2 shows the largest deviation
Figure 1
The structure of the cis isomer showing the atom-numbering scheme and
displacement ellipsoids (30% probability).
² On leave from the Chemistry Department, Delhi University, Delhi 110 007,
India.
ꢁ
Acta Cryst. (2001). C57, 1053±1055
# 2001 International Union of Crystallography
Printed in Great Britain ± all rights reserved 1053

metal-organic compounds
distances). The PtÐS distances in cis-[PtCl2(SPh2)2] are
Ê
2.280 (2) and 2.283 (2) A, which are signi®cantly longer than
the mean value in other cis compounds. These are similar to
the distances found in cis-[PtCl2{S(C6H4Cl)2}2], 2.292 (6) and
The total energy for trans-[PtCl2(SPh2)2] was also calculated
at 20ꢀ intervals for a 360ꢀ rotation around the PtÐS bond,
keeping all other geometric parameters constant. It is inter-
esting to note that the observed conformation of trans-
[PtCl2(SPh2)2] is the one with the lowest energy. It is well
known that EH calculations are reasonably successful in
calculating conformational energies (Jolly, 1991) and it is
concluded that the packing has small effects, not only on bond
distances and angles as normally observed (Johansson et al.,
2000), but also on the conformation in this case.
Ê
2.278 (7) A (Spofford et al., 1971), and shorter than distances
in [PtS4]2+ complexes. Thus, the combined cis(Cl/S)- and
Ê
trans(Cl)-in¯uence may shorten the PtÐS bond, by 0.04 A
compared to [PtS4]2+, but not as much as in other analogous
Experimental
[PtCl2(SPh2)2] was prepared according to Tayim & Bailar (1967). To
prepare the cis compound, [PtCl2(SPh2)2] (0.2 g, 3.13 mmol) was
dissolved in 10 ml of benzene to give a clear solution. Ph3SnH
(0.109 g, 3.195 mmol) dissolved in 2 ml benzene was added and the
reaction mixture was left stirring overnight and then ®ltered. Benzene
was removed to give a brown solid which was dissolved in CH2Cl2/
benzene and MeOH. A dirty white solid was removed by ®ltration
and yellow crystals were obtained from the ®ltrate. The trans
compound was prepared by adding SnCl2 (0.04 g, 2.35 mmol) to a
10 ml acetone solution of [PtCl2(SPh2)2] (0.15 g, 2.35 mmol). The
clear solution became dark and was left overnight. The solution was
®ltered and dark-orange crystals were obtained by slow evaporation.
Figure 2
The structure of the trans isomer showing the atom-numbering scheme
and displacement ellipsoids (30% probability).
Compound (I)
Crystal data
compounds (Table 3). In trans-[PtCl2(SPh2)2], the PtÐS
Ê
distances are 2.3002 (12) A, which is in the normal range for
[PtCl2(C12H10S)2]
Mr = 638.51
Orthorhombic, Pbca
Mo Kꢀ radiation
Cell parameters from 5997
re¯ections
Ê
such bonds [mean 2.301 (9) A]. The cis(Cl/Cl)-in¯uence
a = 10.281 (2) A
ꢁ = 2±29ꢀ
ꢂ = 6.42 mm
T = 293 (2) K
Ê
Ê
2+
shortens it by 0.02 A compared to [PtS4] compounds. The
Ê
1
b = 17.244 (3) A
mean PtÐCl distance found in 33 [PtCl4]2 complexes, 160
Ê
c = 26.382 (5) A
3
Ê
distances, is 2.302 (16) A. The PtÐCl distances in cis-
Ê
V = 4676.9 (16) A
Plate, yellow
0.15 Â 0.13 Â 0.03 mm
Z = 8
Dx = 1.814 Mg m
Ê
[PtCl2(SPh2)2], 2.295 (2) and 2.319 (2) A, are in good agree-
ment with distances found for related cis compounds, mean of
2.312 (11) for 62 distances, while the PtÐCl distance in trans-
3
Ê
[PtCl2(SPh2)2], 2.2786 (15) A, is shorter than in related trans
Ê
compounds, mean of 2.299 (5) A for 14 distances. The cis(S/S)-
in¯uence of SPh2 shortens the PtÐCl bond in trans-
Table 1
Selected geometric parameters (A, ) for (I).
ꢀ
Ê
2
[PtCl2(SPh2)2] by 0.02 A compared to [PtCl4] , but also
Ê
Pt1ÐS1
Pt1ÐS2
Pt1ÐCl1
Pt1ÐCl2
2.2801 (19)
2.2832 (18)
2.319 (2)
S1ÐC111
S1ÐC121
S2ÐC211
S2ÐC221
1.787 (7)
1.785 (8)
1.785 (6)
1.776 (7)
compared to analogous trans-[PtCl2R2] compounds.
The reduced overlap population (ROP) may be used as a
measure of the bond strength. We have calculated the ROP in
the Pt±ligand bonds using the crystallographically observed
2.295 (2)
S1ÐPt1ÐS2
92.39 (6)
175.16 (7)
93.06 (7)
83.68 (7)
173.62 (7)
91.03 (8)
113.7 (2)
106.2 (3)
110.5 (2)
110.3 (2)
C111ÐS1ÐC121
C211ÐS2ÐC221
S1ÐC111ÐC112
S1ÐC111ÐC116
S1ÐC121ÐC122
S1ÐC121ÐC126
S2ÐC211ÐC212
S2ÐC211ÐC216
S2ÐC221ÐC222
S2ÐC221ÐC226
103.3 (3)
103.4 (3)
123.3 (6)
116.0 (6)
115.4 (8)
121.9 (6)
115.7 (5)
123.0 (6)
117.2 (6)
122.2 (6)
È
geometries (Table 3) at the Extended Huckel (EH) level using
S1ÐPt1ÐCl1
S1ÐPt1ÐCl2
S2ÐPt1ÐCl1
S2ÐPt1ÐCl2
Cl1ÐPt1ÐCl2
Pt1ÐS1ÐC111
Pt1ÐS1ÐC121
Pt1ÐS2ÐC211
Pt1ÐS2ÐC221
the program CACAO (Maelli & Prosperpio, 1990). The PtÐS
bonds have higher ROP values than the PtÐCl bonds. This is
true even in the trans compounds where the PtÐS bonds are
equal to or slightly longer than the PtÐCl bonds. All the cis
complexes, except cis-[PtCl2(thioxane)2], have larger ROP
values for the PtÐS bonds than the corresponding trans
compounds, thus following the trends in the PtÐS distances.
However, in the thioxane compounds, the ROP for the trans
compound is the larger one, in spite of the fact that the PtÐS
S1ÐPt1ÐS2ÐC211
S1ÐPt1ÐS2ÐC221
S2ÐPt1ÐS1ÐC111
S2ÐPt1ÐS1ÐC121
17.8 (2)
95.9 (3)
152.6 (3)
94.5 (3)
Pt1ÐS1ÐC111ÐC112
Pt1ÐS1ÐC121ÐC122
Pt1ÐS2ÐC211ÐC212
Pt1ÐS2ÐC221ÐC222
100.3 (6)
143.9 (5)
73.4 (5)
Ê
Ê
distance is 2.298 (2) A, compared with 2.273 (2) A in the cis
compound.
165.1 (5)
ꢁ
1054 Maria H. Johansson et al.
[PtCl2(C12H10S)2]
Acta Cryst. (2001). C57, 1053±1055

metal-organic compounds
Data collection
Table 3
Comparison of PtÐCl and PtÐS distances in analogous cis/trans
complexes together with their ROP values.
Bruker SMART CCD diffrac-
tometer
! scans
Absorption correction: empirical
(SADABS; Sheldrick, 1996)
Tmin = 0.446, Tmax = 0.831
32399 measured re¯ections
5802 independent re¯ections
4144 re¯ections with I > 2ꢃ(I)
Rint = 0.064
Ê
PtÐCl (A)
Ê
PtÐS (A)
ꢁ
max = 28.3ꢀ
Compound
ROP
ROP
h = 12 ! 13
k = 22 ! 22
l = 33 ! 35
cis-[PtCl2{S(C6H5)2}2]a
2.295 (2)
2.319 (2)
2.2786 (15)
2.315 (1)
2.319 (1)
2.288 (2)
2.321 (2)
2.327 (2)
2.300 (2)
0.449
0.416
0.446
0.440
0.434
0.448
0.439
0.438
0.441
2.280 (2)
2.283 (2)
2.3002 (12)
2.269 (1)
2.272 (1)
2.303 (2)
2.273 (2)
2.273 (2)
2.298 (2)
0.539
0.518
0.507
0.531
0.536
0.517
0.512
0.520
0.534
trans-[PtCl2{S(C6H5)2}2]a
cis-[PtCl2(dms)2]b
Re®nement
Re®nement on F2
R[F2 > 2ꢃ(F2)] = 0.045
wR(F2) = 0.106
S = 1.16
5802 re¯ections
w = 1/[ꢃ2(Fo2) + (0.0309P)2
+ 15.3500P]
trans-[PtCl2(dms)2]c
cis-[PtCl2(thioxane)2]d
where P = (Fo2 + 2Fc2)/3
(Á/ꢃ)max = 0.001
trans-[PtCl2(thioxane)2]d
3
Ê
Áꢄmax = 1.71 e A
Notes: (a) this study; (b) Horn et al. (1990), dms is SMe2; (c) Johansson et al. (2001); (d)
Bugarcic et al. (1993), thioxane is SC4H8O.
3
Ê
1.08 e A
262 parameters
H-atom parameters constrained
Áꢄmin
=
Compound (II)
Ê
H atoms were treated as riding with a CÐH distance of 0.93 A. In
(I), the maximum and minimum residual electron densities were
Ê
located 0.87 and 0.78 A from Pt1, respectively. The corresponding
Crystal data
3
[PtCl2(C12H10S)2]
Mr = 638.51
Monoclinic, P21/c
Dx = 1.830 Mg m
Mo Kꢀ radiation
Ê
Ê
values in (II) were 0.89 A from Cl1 and 0.81 A from Pt1.
Cell parameters from 5997
re¯ections
Ê
For both compounds, data collection: SMART (Siemens, 1995);
cell re®nement: SAINT (Siemens, 1995); data reduction: SAINT;
program(s) used to solve structure: SHELXS97 (Sheldrick, 1997);
program(s) used to re®ne structure: SHELXL97 (Sheldrick, 1997);
molecular graphics: DIAMOND (Brandenburg, 2000); software used
to prepare material for publication: SHELXL97.
a = 5.8742 (12) A
Ê
b = 16.980 (3) A
ꢁ = 2±30ꢀ
1
Ê
c = 11.733 (2) A
ꢂ = 6.47 mm
T = 293 (2) K
ꢅ = 97.99 (3)ꢀ
V = 1158.9 (4) A
Z = 2
3
Ê
Plate, orange
0.35 Â 0.19 Â 0.08 mm
Data collection
Bruker SMART CCD diffrac-
tometer
! scans
Absorption correction: empirical
(SADABS; Sheldrick, 1996)
Tmin = 0.177, Tmax = 0.383
9455 measured re¯ections
3583 independent re¯ections
2811 re¯ections with I > 2ꢃ(I)
Rint = 0.046
Financial assistance from the Swedish Natural Science
Research Council and the Crafford Foundation is gratefully
acknowledged.
ꢁ
max = 31.8ꢀ
h = 6 ! 8
k = 24 ! 21
l = 17 ! 17
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: GD1157). Services for accessing these data are
described at the back of the journal.
Re®nement
Re®nement on F2
R[F2 > 2ꢃ(F2)] = 0.036
wR(F2) = 0.100
S = 1.09
3583 re¯ections
w = 1/[ꢃ2(Fo2) + (0.0424P)2
+ 2.6752P]
where P = (Fo2 + 2Fc2)/3
(Á/ꢃ)max < 0.001
References
3
Ê
Áꢄmax = 1.27 e A
3
Ê
2.07 e A
Allen, F. H. & Kennard, O. (1993). Chem. Des. Autom. News, 8, 1, 31±37.
Brandenburg, K. (2000). DIAMOND. Crystal Impact GbR, Bonn, Germany.
133 parameters
H-atom parameters constrained
Áꢄmin
=
Ê
Bugarcic, Z., Lovqvist, K. & Oskarsson, A. (1993). Acta Chem. Scand. 47, 554±
È
559.
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(1990). Acta Cryst. C46, 135±136.
Table 2
Selected geometric parameters (A, ) for (II).
Ê
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ꢀ
Ê
Ê
Johansson, M. H., Otto, S., Roodt, A. & Oskarsson, A. (2000). Acta Cryst. B56,
226±233.
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Pt1ÐCl1
Pt1ÐS1
2.2786 (15)
2.3002 (12)
S1ÐC111
S1ÐC121
1.783 (5)
1.789 (5)
Maelli, C. & Prosperpio, D. M. (1990). J. Chem. Educ. 67, 399±402.
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È
Sheldrick, G. M. (1996). SADABS. University of Gottingen, Germany.
Sheldrick, G. M. (1997). SHELXL97 and SHELXS97. University of Gott-
Cl1ÐPt1ÐS1
84.80 (5)
95.20 (5)
107.32 (16)
111.79 (16)
122.0 (4)
S1ÐC111ÐC116
C111ÐS1ÐC121
S1ÐC121ÐC122
S1ÐC121ÐC126
117.5 (4)
102.4 (2)
124.2 (4)
115.4 (4)
Cl1iÐPt1ÐS1
Pt1ÐS1ÐC111
Pt1ÐS1ÐC121
S1ÐC111ÐC112
È
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Cl1ÐPt1ÐS1ÐC111
Cl1ÐPt1ÐS1ÐC121
76.55 (18)
171.97 (19)
Pt1ÐS1ÐC111ÐC112
Pt1ÐS1ÐC121ÐC122
23.1 (4)
96.5 (5)
Symmetry code: (i) x; y; z.
ꢁ
Acta Cryst. (2001). C57, 1053±1055
Maria H. Johansson et al. [PtCl2(C12H10S)2] 1055