Reactivity of Bis(silyl)platinum(II) complexes toward organic isothiocyanates: Preparation and structures of (dithiocarbonimidato)- And (diphenylsilanedithiolato)platinum(II) complexes, cis-[Pt(S2C=NPh) L2] and cis-[Pt(S2SiPh2)L2] (L = PMe2Ph, PEt3; L-L = dppp)

Article abstract of DOI:10.1021/om8006079

Reactions of the bis(silyl)platinum(II) complexes [Pt(SiHPh ₂)₂L₂] (L = PMe₃, PMe₂Ph, PEt₃; L-L = dppp (1,3-bis(diphenylphosphino)propane)) with organic isothiocyanates (RNCS) produced the dithiocarbonimidato complexes [Pt(S ₂C=NR)L₂] (R = Ph, p-tolyl, 2,6-Me₂C ₆H₃, i-Pr) or the diphenylsilanedithiolato complexes [Pt(S₂SiPh₂)L₂], depending on the reaction temperature, the stoichiometry, and the nature of the phosphine ligand.

Full text of DOI:10.1021/om8006079

5566
Organometallics 2008, 27, 5566–5570
Reactivity of Bis(silyl)platinum(II) Complexes toward Organic
Isothiocyanates: Preparation and Structures of
(Dithiocarbonimidato)- and (Diphenylsilanedithiolato)platinum(II)
Complexes, cis-[Pt(S2CdNPh)L2] and cis-[Pt(S2SiPh2)L2]
(L ) PMe2Ph, PEt3; L-L ) dppp)
Kyung-Eun Lee,†,‡ Xiaohong Chang,†,§ Yong-Joo Kim,*,† Hyun Sue Huh,‡ and
Soon W. Lee‡
Departments of Chemistry, Kangnung National UniVersity, Kangnung 210-702, Korea, Liaoning
UniVersity, Shenyang 110036, People’s Republic of China, and Sungkyunkwan UniVersity,
Natural Science Campus, Suwon 440-746, Korea
ReceiVed March 19, 2008
Reactions of the bis(silyl)platinum(II) complexes [Pt(SiHPh2)2L2] (L ) PMe3, PMe2Ph, PEt3; L-L )
dppp (1,3-bis(diphenylphosphino)propane)) with organic isothiocyanates (RNCS) produced the dithio-
carbonimidato complexes [Pt(S2CdNR)L2] (R ) Ph, p-tolyl, 2,6-Me2C6H3, i-Pr) or the diphenylsi-
lanedithiolato complexes [Pt(S2SiPh2)L2], depending on the reaction temperature, the stoichiometry, and
the nature of the phosphine ligand.
is rare.3,4 Recently, we reported the novel reactivity of the Pt(II)
bis(silyl) complexes toward isocyanides to afford the Pt(II)
Introduction
Bis(silyl)platinum(II) complexes are considered important
intermediates in the Pt-catalyzed mono- or bis(silylation) of
unsaturated organic compounds, and they have been utilized as
stoichiometric reactants for the preparation of unique silyl
complexes.1,2 Alkenes, alkynes, and 1,3-dienes typically react
with these complexes via Pt-Si bond cleavage or migration.
However, the insertion of other unsaturated organic compounds
such as organic isonitriles (RNC), nitriles (RCN), and isothio-
cyanates (RNCS) into the Pt-Si bond in this type of complex
isocyanide complexes [Pt(SiHPh2)2(CNR)(PR′3)] (R′ ) Me, Et),
whose reactivity depended on the reactants or spectator ligands.4
In this work we report the selective formation of the Pt(II)
dithiocarbonimidato and diphenylsilanedithiolato complexes
[Pt(S2CdNR)L2] (R ) Ph, p-tolyl, 2,6-Me2C6H3, i-Pr) and
[Pt(S2SiPh2)L2] from the reactions of the Pt(II) bis(silyl)
complexes and organic isothiocyanates.
Results and Discussion
* To whom correspondence should be addressed. E-mail: yjkim@
kangnung.ac.kr. Tel: Int + 82 + 33-640-2308. Fax: Int + 82 + 33-647-
1183.
Reactions of [Pt(SiHPh2)2L2] (L ) PMe2Ph, PMe3; L-L )
dppp (1,3-bis(diphenylphosphino)propane)) with 2 equiv of
ArNCS (Ar ) phenyl, p-tolyl) at either room temperature
(1, 4, and 5) or 50 °C (2 and 3) in THF gave the Pt(II)
dithiocarbonimidato complexes with a 30-41% yield (eqs 1
and 2). As the reaction progressed, the IR spectra of a reaction
mixture clearly showed the disappearance of the Si-H bands
at 2026-2081 cm-1, which are characteristic of the starting
materials, and the appearance of new NdC bands at 1547-1578
cm-1, which are characteristic of the products. Structural
characterization of 1 and 4 by X-ray diffraction definitely
confirmed the identity of these complexes.
† Kangnung National University.
‡ Sungkyunkwan University.
§ Liaoning University.
(1) (a) Chatt, J.; Eaborn, C.; Kapoor, P. N. J. Chem. Soc. A 1970, 881.
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As shown in eqs 1 and 2, although the Pt(II) bis(silyl)
complexes containing phosphines such as PMe2Ph, PMe3, and
10.1021/om8006079 CCC: $40.75
2008 American Chemical Society
Publication on Web 10/09/2008

Platinum(II) Dithiocarbonimidato Complexes
Organometallics, Vol. 27, No. 21, 2008 5567
dppp reacted with 2 equiv of ArNCS to give the Pt(II)
dithiocarbonimidato complexes, excess ArNCS in the reaction
mixture hindered the isolation of the Pt(II) products. In contrast,
the corresponding 1:1 reaction of the PEt3 complex [Pt-
(SiHPh2)2(PEt3)2] and ArNCS (Ar ) Ph, p-tolyl) allowed us to
isolate the diphenylsilanedithiolato complex [Pt(S2SiPh2)-
(PEt3)2] (6) as white crystals in 30-35% yield (eq 3). On the
other hand, the PMe2Ph complex [Pt(SiHPh2)2(PMe2Ph)2]
reacted with 1 or 2 equiv of RNCS (R ) p-tolyl, i-Pr) to produce
a mixture of the diphenylsilanedithiolato complex [Pt(S2SiPh2)-
(PMe2Ph)2] (7), the dithiocarbonimidato complex [Pt(S2Cd
NR)(PMe2Ph)2] (R ) p-tolyl (2), i-Pr (8)), and unidentified oily
materials (eq 4). Interestingly, heating the reaction mixture
converted it into the Pt(II) dithiocarbonimidato complex as a
single product. The above results strongly indicate that the
phosphine ligands in the starting complexes exert a critical
influence on the final products in these reactions.
Several papers have previously proposed sulfur abstraction
for the formation of dithiocarbonimidato complexes, which is
believed to occur in our reactions. For example, Haszeldine and
co-workers5 reported that the Pt(0) complexes [Pt(allene)L2],
[PtL4], and [Pt(PhNCS)L2] (L ) PPh3) reacted with excess
organic isothiocyanates (RNCS; R ) Ph, Me) to give the Pt(II)
dithiocarbonimidato complex [Pt(S2CdNR)L2] as a major
product as well as the isonitrile-dithiocarbonimidato-Pt(II)
complex [Pt(CNPh)(S2CdNPh)L2] as a minor product. In
6
addition, the Pd(0) complexes [Pd2(dba)3] · CHCl3 (in the
7b
presence of PPh3) and Pd(PR3)n (n ) 2, 4; PR3 ) PMe3,
PMe2Ph, PMePh2, P-i-Pr3) were shown to react with RNCS (R
) Me, Ph, C(O)OEt) to give the Pd dithiocarbonimidato
complexes [Pd(S2CdNR)(PR3)2]. Furthermore, the Powell8 and
Thewissen9 groups reported that Ru(0) and Rh(I) complexes
reacted with RNCS (R ) Ph, alkyl) to produce the correspond-
ing dithiocarbonimidato or isonitrile-dithiocarbonimidato com-
plexes, depending on the amounts of the added isothiocyanates.
Finally, CpCo(PMe3)2,7a [Fe3(CO)12],10 and [Mo(CO)6]10 reacted
with PhNCS to give the isonitrile complexes CpCo(PMe3)(CN-
Ph), [Fe(CO)4(CNPh)], and [Mo(CO)5(CNPh), respectively.
Reactions in this report seem to proceed by the initial
coordination of RNCS to [Pt(SiHPh2)L2] or the elimination of
H2SiPh2 from [Pt(SiHPh2)L2] to produce the Pt silylene inter-
mediate followed by the liberation of isocyanides. Unfortunately,
we could not detect Ph2HSi-SiHPh2 in the NMR or mass
spectra of the reaction mixture. The disilane (Ph2HSi-SiHPh2)
is expected to be formed by the reductive elimination from
[Pt(SiHPh2)L2] to produce a Pt(0) intermediate, which would
subsequently react with excess organic isothiocyanate to give
the Pt(II) dithiocarbonimidato complex [Pt(S2CdNR)L2] by the
dimerization of RNCS as described in previous reports.9 With
limited experimental evidence, however, there is no point in
speculation on the mechanism at this time. Further studies to
elucidate the mechanism are required.
The crystal and refinement data of complexes 1, 4, 6, and 7
are summarized in Table 1. Figures 1 and 2 are ORTEP
drawings of the complexes 1 and 4, respectively, both of which
show a slightly distorted square planar geometry consisting of
two phosphine ligands and two bridging sulfide (µ-S) ligands
attached to the carbonimidato group (ArNdC). The two doublets
in 31P{1H} NMR spectra of these complexes are flanked with
Pt satellites, supporting the presence of nonequivalent phosphine
ligands of the dithiolato moiety coordinated to the Pt center.
The N1-C17 (1.268(7) Å) and N1-C18 (1.411(8) Å) bond
lengths in Figure 1 and N1-C28 (1.270(1) Å) and the N1-C29
(1.450(2) Å) bond lengths in Figure 2 indicate a CdNR moiety
in both complexes. The molecular structures of complexes 6
(Figure 3) and 7 (Figure 4) also demonstrate a square-planar
geometry consisting of two cis PR3 ligands and two bridging
sulfide (µ-S) groups bonded to the diphenylsilyl group (SiPh2).
The Pt-S bond lengths (2.337-2.340 Å) in the Pt(II) dithio-
carbonimidato complexes (1 and 4) are similar to those (2.341(5)
Before recrystallization, the IR spectra of the crude products
in this work (eqs 1-4) displayed a common absorption band
(ν(CN)) at ∼2160 cm-1, which is interpreted as the presence
of the isonitrile group coordinated to the Pt center. We used
spectroscopy (IR and NMR) and GC-mass spectrometry to
identify the characteristic signals assigned to the isocyanide and
H2SiPh2; these signals strongly support the formation of the
isonitrile-coodinated intermediates. In spite of several attempts,
however, we failed to isolate the isonitrile-dithiocarbonimi-
dato-Pt complexes [Pt(S2CdNR)(CNR)L2] or the isonitrile-
diphenylsilanedithiolato-Pt complexes [Pt(S2SiPh2)(CNR)L2],
which may be formed by the coordination of the liberated
isonitrile to the final product (complexes 1-7). It should be
mentioned that most of the reaction products have been isolated
from oily reaction mixtures in relatively low yields.
It is worth noting that the reactions of the Pt(II) bis(silyl)
complex, except [Pt(SiHPh2)2(PEt3)2], with excess RNCS (R
) Ph, p-tolyl, i-Pr) typically give the dithiocarbonimidato
complex as a major product. In sharp contrast, the corresponding
1:1 reaction of the PEt3 complex [Pt(SiHPh2)2(PEt3)2] and RNCS
produces the diphenylsilanedithiolato complex as a major
product in high yield (eq 3). The ability of [Pt(SiHPh2)2(PEt3)2]
to exhibit higher selectivity for diphenylsilanedithiolato complex
formation may result from the bulky triethylphosphine dissocia-
tion in the formation of an intermediate.
(5) Bowden, F. L.; Giles, R.; Haszeldine, R. N. J. Chem. Soc., Chem.
Commun. 1974, 578.
(6) Ahmed, J.; Itoh, K.; Matsuda, I.; Ueda, F.; Ishii, Y.; Ibers, J. A.
Inorg. Chem. 1977, 16, 620.
(7) (a) Werner, H.; Lotz, S.; Heiser, B. J. Organomet. Chem. 1981, 209,
197. (b) Bertleff, W.; Werner, H. Chem. Ber. 1982, 115, 1012.
(8) Harris, R. O.; Powell, J.; Walker, A.; Yaneff, P. V. J. Organomet.
Chem. 1977, 141, 217.
(9) Thewissen, D. H. M. W.; Van Gaal, H. L. M. J. Organomet. Chem.
1979, 172, 69.
(10) Manuel, T. A. Inorg. Chem. 1964, 3, 1703.
(11) (a) Schierl, R.; Nagel, U.; Beck, W. Z. Naturforsch. 1984, 39b,
649. (b) Schierl, R.; Nagel, U.; Beck, W. Chem. Ber. 1982, 115, 1665.
(3) (a) Tanabe, M.; Osakada, K. Organometallics 2001, 20, 2118. (b)
Yamada, T.; Tanabe, M.; Osakada, K.; Kim, Y.-J. Organometallics 2004,
20, 4771.
(4) Kim, Y.-J.; Choi, E.-H.; Lee, S. W. Organometallics 2003, 22, 3316.

5568 Organometallics, Vol. 27, No. 21, 2008
Lee et al.
Table 1. X-ray Data Collection and Structure Refinement Details for Complexes 1, 4, 6, and 7
1
4 · CH2Cl2 · H2O
6
7
formula
fw
C23H27NP2S2Pt
638.61
C35H35Cl2NOP2S2Pt
877.69
C24H34P2S2SiPt
671.75
C28H32P2S2SiPt
717.78
temp, K
293(2)
293(2)
293(2)
293(2)
cryst size (mm3)
0.16 × 0.12 × 0.06
0.18 × 0.16 × 0.14
monoclinic
C2/c
0.48 × 0.46 × 0.44
orthorhombic
Pnma
0.18 × 0.16 × 0.14
monoclinic
C2/c
cryst syst
space group
triclinic
j
P1
a, Å
b, Å
c, Å
9.611(1)
10.071(1)
12.944(2)
94.73(1)
105.69(1)
92.37(1)
1199.4 (3)
2
27.652(4)
13.789(2)
20.128(2)
17.707 (2)
13.505(2)
11.816(1)
14.898(2)
11.839(9)
16.944(4)
R, deg
ꢀ, deg
112.91(1)
106.88(1)
γ, deg
V, Å3
7070(2)
8
1.649
4.358
3472
2825.7(6)
4
1.579
5.279
1328
2859.8(8)
4
1.667
5.223
640
Z
dcalcd, g cm-3
1.768
6.167
624
µ, mm-1
F(000)
Tmin
Tmax
0.3949
0.7927
4450
4191
3677
262
0.684
-0.744
1.027
0.2512
0.7080
6250
6114
3619
0.2308
0.3790
2580
2580
2365
0.6523
0.8987
2611
2510
2316
no. of measd rflns
no. of unique rflns
no. of rflns with I > 2σ(I)
no. of params refined
369
152
156
max in ∆F (e Å-3
)
)
0.904
-1.315
1.005
0.0586
0.1148
0.797
-0.622
1.066
0.0292
0.0740
0.557
-0.583
1.042
0.0223
0.0543
min in ∆F (e Å-3
GOF on F2
R1a
0.0298
0.0666
wR2b
2
2 2
a R1 ) ∑[|Fo| - |Fc|]/∑|Fo|]. b wR2 ) ∑[w(Fo - Fc ) ]/∑[w(Fo2)2]1/2
.
Figure 1. ORTEP drawing of 1 showing the atom-labeling scheme
and 50% probability thermal ellipsoids. Selected bond lengths (Å)
and angles (deg): Pt1-P1 ) 2.270(1), Pt1-P2 ) 2.277(2), Pt1-S1
) 2.337(2), Pt1-S2 ) 2.339(2), S1-C17 ) 1.755(6), S2-C17 )
1.781(6), N1-C17 ) 1.268(7), N1-C18 ) 1.411(8); P1-Pt1-P2
) 99.26(5), P1-Pt1-S1 ) 169.34, P2-Pt1-S1 ) 91.35(5),
P1-Pt1-S2 ) 94.32(5), P2-Pt1-S2 ) 165.71(5), S1-Pt1-S2
) 75.21(5), C17-S1-Pt1 ) 88.83(19), C17-S2-Pt1 ) 88.2(2),
C17-N1-C18 ) 123.2(5), N1-C17-S1 ) 122.5(4), N1-C17-S2
) 129.9(5), S1-C17-S2 ) 107.6(3).
Figure 2. ORTEP drawing of 4 · CH2Cl2 · H2O. Selected bond
lengths (Å) and angles (deg): Pt1-P1 ) 2.248(3), Pt1-P2 )
2.257(3), Pt1-S1 ) 2.337(3), Pt1-S2 ) 2.340(3), S1-C28 )
1.770(12), S2-C28 ) 1.766(12), N1-C28 ) 1.270(1), N1-C29
) 1.450(2); P1-Pt1-P2 ) 92.0(1), P1-Pt1-S1 ) 171.0(1),
P2-Pt1-S1 ) 97.0(1), P1-Pt1-S2 ) 95.3(1), P2-Pt1-S2 )
172.3(1), S1-Pt1-S2 ) 75.7(1), C28-S1-Pt1 ) 87.9(4),
C28-S2-Pt1 ) 87.9(4), C28-N1-C29 ) 119(1), N1-C28-S2
) 122.2(9), N1-C28-S1 ) 129(1), S2-C28-S1 ) 108.5(6).
and 2.327(5) Å) in cis-[Pt(S2CdNCH2Ph)(PEt3)2].11a These
Pt-S bond lengths are slightly shorter than those (2.392 Å for
6 and 2.376 Å for 7) in the Pt(II) diphenysilanedithiolato
complexes, probably reflecting more distorted metallacyclobu-
tane rings in the former dithiocarbonimidato complexes as
compared to those in the latter complexes. These Pt-S lengths
are comparable to those (2.367(15) and 2.333(17) Å) in
[Pt(S2Si(Tbt)(Mes)(PPh3)2] (Tbt ) 2,4,6-tris[bis(trimethylsilyl)-
methyl]phenyl; Mes ) 2,4,6-trimethylphenyl)12 and are also
comparable to the Pd-S bond lengths (2.362(1) and 2.392(1)
Å) in [Pd(S2SiMe2)(PEt3)2].13 These bonding parameters indicate
that the Pt(II) dithiolato complexes in this work are more
(12) Tanabe, T.; Takeda, N.; Tokitoh, N. Eur. J. Inorg. Chem. 2007,
1225.
(13) Komuro, T.; Matsuo, T.; Kawaguchi, H.; Tatsumi, K. Chem.
Commun. 2002, 988.

Platinum(II) Dithiocarbonimidato Complexes
Organometallics, Vol. 27, No. 21, 2008 5569
analyses. IR spectra were recorded on a Perkin-Elmer BX spec-
trophotometer. NMR (1H, 13C{1H}, and 31P{1H}) spectra were
obtained on a JEOL Lambda 300 MHz spectrometer. Chemical
shifts were referenced to internal Me4Si (1H and 13C{1H}) and to
external 85% H3PO4 (31P{1H}). PhNCS, p-tolylNCS, 2,6-
Me2C6H3NCS, and i-PrNCS were purchased and used without
further purification. [Pt(SiHPh2)2L2] (L ) PMe3, PEt3, PMe2Ph)
complexes were prepared according to the literature14 with some
modified methods. [Pt(SiHPh2)2(dppp)] was prepared by treating
[Pt(SiHPh2)2(PMe3)2] with 1 equiv of dppp. IR (KBr, cm-1): ν(SiH)
2063, 2026. 1H NMR (CDCl3, δ): 1.90 (m, 2H, PCH2CH2-), 2.46
(m, 4H, PCH2-), 4.97 (dd, 2H, JP-H ) 17 Hz, JPt-H ) 68 Hz,
SiH), 6.91-7.34 (m, 40H, Ph). 13C{1H} NMR (CDCl3): 20.2 (s,
PCH2CH2-), 28.8 (t, JC-P ) 14.9 Hz, PCH2-), 126.4, 126.7, 127.9
(t, JC-P ) 4.9 Hz), 129.8, 132.4, 132.7, 133.0, 133.3 (t, JC-P ) 6.2
Hz, JPt-C ) 27 Hz), 136.6 (s, JPt-C ) 22 Hz), 141.8 (t, JC-P ) 3.8
Hz, JPtC ) 35 Hz). 31P{1H} NMR (CDCl3): 5.13 (s, JPt-P ) 1604
Hz, JP-Si ) 118 Hz).
Figure 3. ORTEP drawing of 6. Selected bond lengths (Å) and
angles (deg): Pt1-P1 ) 2.269(1), Pt1-S1 ) 2.392(1), S1-Si1 )
2.0992(16); P1-Pt1-S1 ) 85.27(4), Si1-S1-Pt1 ) 86.90(5).
Preparation of Complexes 1, 4, and 5. THF (7 mL) and PhNCS
(0.158 g, 1.17 mmol) were added to a Schlenk flask containing
[Pt(SiHPh2)2(PMe2Ph)2] (0.490 g, 0.585 mmol). After it was stirred
for 40 h at room temperature, the reaction mixture was completely
evaporated under vacuum and the resulting oily residue was
solidified with ether/CH2Cl2 (7:1). The solids were filtered and
washed with hexane (2 × 2 mL). Recrystallization with ether/
CH2Cl2 (3:1) gave white crystals of [Pt(S2CdNPh)(PMe2Ph)2], (1;
1
0.150 g, 41%). IR (KBr, cm-1): ν(CN) 1564. H NMR (CDCl3,
δ): 1.57 (dd, JP-H ) 9.9, 51 Hz, 12H, PMe2Ph), 7.00-7.05 (m,
1H, Ph), 7.16-7.19 (m, 2H, Ph), 7.26-7.47 (m, 12H, Ph). 13C{1H}
NMR (CDCl3): 14.2 (d, JP-C ) 27 Hz, PMe2Ph), 14.7 (d, JP-C
)
25 Hz, PMe2Ph), 122.3, 123.1, 128.4, 128.6, 128.8, 130.5, 130.7,
130.8, 130.9, 130.9, 147.1, 173.6 (CN). 31P{1H} NMR (CDCl3):
-19.2 (d, J ) 27 Hz, JPt-P ) 2982), -19.9 (d, J ) 27 Hz, JPt-P
)
2956 Hz). Anal. Calcd for C23H27NP2S2Pt: C, 43.26; H, 4.26; N,
2.19. Found: C, 42.90; H, 4.29; N, 2.27.
Complexes 4 and 5 were prepared analogously. Data for
[Pt(S2CdN-Ph)(dppp)] (4; 30%) are as follows. IR (KBr, cm-1):
ν(CN) 1558. 1H NMR (CDCl3, δ): 2.01 (m, 2H, PCH2CH2-), 2.56
(m, 4H, PCH2), 6.82-6.86 (m, 3H, Ph), 7.05-7.12 (m, 2H, Ph),
7.28-7.33 (m, 7H, Ph), 7.50 (m, 13H, Ph). 13C{1H} NMR (CDCl3):
19.9 (s, PCH2CH2-), 25.3 (br, PCH2), 122.5, 123.0, 128.6, 128.8,
128.9, 130.0, 131.5, 133.2, 133.3, 133.5, 147.5, 173.6 (CN).
31P{1H} NMR (CDCl3): -4.74 (d, J ) 38 Hz, JPt-P ) 2801 Hz),
-5.13 (d, J ) 35 Hz, JPt-P ) 2887 Hz). Anal. Calcd for
C34H31NP2S2Pt · 0.5CH2Cl2: C, 50.70; H, 3.95; N, 1.71. Found: C,
50.61; H, 3.95; N, 1.79. Data for [Pt(S2CdNC6H4-p-Me)(dppp)]
Figure 4. ORTEP drawing of 7. Selected bond lengths (Å) and
angles (deg): Pt1-P1 ) 2.267(1), Pt1-S1 ) 2.376(1), S1-Si1 )
2.113(1); P1-Pt1-S1 ) 89.57(4), Si1S1-Pt1 ) 87.97(4).
1
(5; 37%) are as follows. IR (KBr, cm-1): ν(CN) 1547. H NMR
(CDCl3, δ): 2.01-2.26 (m, 2H, PCH2CH2-), 2.21 (s, 3H, Me),
2.50-2.64 (m, 4H, PCH2), 6.94-7.03 (m, 4H, Ph), 7.26-7.38 (m,
12H, Ph), 7.52-7.60 (m, 8H, Ph). 13C{1H} NMR (CDCl3): 19.7
symmetric (equal M-S bond lengths) than those of other Pt(II)
or Pd(II) complexes having bridging silane groups.
(s, PCH2CH2-), 20.9 (s, Me), 25.3 (br, PCH2), 122.5 (s, JC-P
)
In summary, we carried out several reactions of Pt(II)
bis(silyl) complexes with organic unsaturated isothiocyanates
(RNCS) under various conditions. These reactions produced
novel Pt(II) dithiocarbonimidato complexes [Pt(S2CdNR)L2]
(R ) Ph, p-tolyl, 2,6-Me2C6H3, i-Pr) or Pt(II) diphenylsi-
lanedithiolato complexes [Pt(S2SiPh2)L2], depending on the
temperature, stoichiometry, and the nature of the phosphine
ligand, and may proceed via either sulfur abstraction from
organic isothiocyanate-coordinated complexes or the silyl
migration from them.
4.4 Hz), 128.5 (dd, JC-P ) 4.4, 10 Hz), 128.8, 131.0, 131.1, 132.0,
133.0 (dd, JC-P ) 4.9, 10 Hz), 144.3, 172.9 (CN). 31P{1H} NMR
(CDCl3): -4.75 (d, J ) 35 Hz, JPt-P ) 2821 Hz), -5.29 (d, J )
38 Hz, JPt-P ) 2858 Hz). Anal. Calcd for C35H33NP2S2Pt: C, 53.29;
H, 4.22; N, 1.78. Found: C, 53.50; H, 4.32; N, 1.58.
Preparation of Complexes 2 and 3. THF (7 mL) and p-
tolylNCS (0.158 g, 1.10 mmol) were added to a Schlenk flask
containing [Pt(SiHPh2)2(PMe2Ph)2] (0.422 g, 0.504 mmol). After
it was stirred for 6 h at 50 °C, the reaction mixture was completely
evaporated under vacuum, and the resulting oily residue was
solidified with ether/CH2Cl2 (14:1). The solids were filtered and
washed with hexane (2 × 2 mL). Recrystallization with ether/
CH2Cl2 (6:1) gave white crystals of [Pt(S2CdNC6H4-p-
Me)(PMe2Ph)2] (2; 0.105 g, 32%). IR (KBr, cm-1): ν(CN) 1578.
Experimental Section
General Methods. All manipulations of air-sensitive compounds
were performed under N2 or Ar by standard Schlenk-line techniques.
Solvents were distilled from Na-benzophenone. The analytical
laboratory at Kangnung National University carried out elemental
(14) Kim, Y.-J.; Park, J.-I.; Lee, S.-C.; Osakada, K.; Tanabe, M.; Choi,
J.-C.; Koizumi, T.; Yamamoto, T. Organometallics 1999, 18, 1349.

5570 Organometallics, Vol. 27, No. 21, 2008
Lee et al.
1H NMR (CDCl3): 1.57 (dd, JP-H ) 9.9, 20 Hz, 12H, PMe2Ph),
2.30 (s, 3H, Me), 7.10 (s, 4H, Ph), 7.27-7.47 (m, 10H, Ph).
13C{1H} NMR (CDCl3): 14.2 (dd, JC-P ) 2.5, 29 Hz, PMe2Ph),
14.7 (dd, JC-P ) 2.5, 29 Hz, PMe2Ph), 21.0 (s, Me), 122.1, 128.6,
128.7, 129.0, 130.5, 130.6, 130.7, 130.8, 130.9, 132.3, 144.4, 172.5
(CN). 31P{1H} NMR (CDCl3): -19.1 (d, J ) 27 Hz, JPt-P ) 2978),
-19.9 (d, J ) 27 Hz, JPt-P ) 2955 Hz). Anal. Calcd for
C24H29NP2S2Pt: C, 44.17; H, 4.48; N, 2.15. Found: C, 44.66; H,
4.66; N, 1.89.
(S2SiPh2)(PMe2Ph)2], (7; 0.061 g, 22%). 1H NMR (CDCl3, δ): 1.64
(d, JP-H ) 10 Hz, JPt-H ) 34 Hz,, 12H, PMe2Ph), 7.26-7.50 (m,
16H, Ph), 7.84-7.90 (m, 4H, Ph). 13C{1H} NMR (CDCl3): 14.3
(d, JC-P ) 42 Hz, JPt-C ) 31 Hz, PMe2Ph), 127.4, 128.5, 129.1,
130.9, 133.5, 144.6. 31P{1H} NMR (CDCl3): -17.3 (s, JPt-P
)
3076 Hz). Anal. Calcd for C28H32P2S2SiPt: C, 46.85; H, 4.49.
Found: C, 47.01; H, 4.64.
An analogous reaction of [Pt(SiHPh2)2(PMe2Ph)2] with i-PrNCS
gave a mixture of [Pt(S2SiPh2)(PMe2Ph)2] (7) and [Pt(S2Cd
NR)(PMe2Ph)2] (8; R ) i-Pr). Data for 8 are as follows. IR (KBr,
Complex 3 was prepared analogously. Data for [Pt(S2CdNC6H3-
1
cm-1): ν(CN) 1583. H NMR (CDCl3, δ): 1.23 (d, J ) 6.2 Hz,
2,6-Me2)(PMe3)2] (3; 33%) are as follows. IR (KBr, cm-1): ν(CN)
1
6H, CH(CH3)2), 1.58 (dd, J ) 3.1, 10 Hz, JPt-H ) 33 Hz, 12H,
PMe2Ph), 4.35 (sept, J ) 6.2 Hz, 1H, CH(CH3)2), 7.29-7.48 (m,
10H, Ph). 13C{1H} NMR (CDCl3): 14.2 (dd, JC-P ) 4.4, 28 Hz,
PMe2Ph), 14.7 (dd, JC-P ) 5.6, 27 Hz, PMe2Ph), 23.6 (CH(CH3)2),
53.4 (CH(CH3)2), 128.6, 128.7, 130.6, 130.7, 130, 8, 130.9, 133.1
(dd, JC-P ) 6.8, 10 Hz), 133.7, 166.0 (CN). 31P{1H} NMR (CDCl3):
-19.5 (d, J ) 26 Hz, JPt-P ) 2948 Hz), -19.9 (d, J ) 26 Hz,
JPt-P ) 2955 Hz). Complexes 7 and 8 could not be separated due
to similarities in solubility.
1564. H NMR (CDCl3): 1.63 (br, 18H, PMe3), 2.18 (s, 6H, Me),
6.86 (dd, 1H, J ) 6.6, 8.1 Hz, Ph). 6.98 (d, J ) 7.3 Hz, 2H, Ph).
13C{1H} NMR (CDCl3): 16.6 (d, JC-P ) 38 Hz, JPt-C ) 38 Hz,
PMe3), 18.4 (s, CH3), 122.5, 127.2, 128.9, 145.0, 170.9 (CN).
31P{1H} NMR (CDCl3): -29.7 (br s, JPt-P ) 2923 Hz), -30.6 (br
s, JPt-P ) 2901 Hz). Anal. Calcd for C15H27NP2S2Pt: C, 33.21; H,
5.02; N, 2.58. Found: C, 33.48; H, 5.05, N, 2.44.
Preparation of Complex 6. THF (7 mL) and PhNCS (0.103 g,
0.762 mmol) were added to
a Schlenk flask containing
Structure Determination. All X-ray data were collected with
a Siemens P4 diffractometer equipped with a Mo X-ray tube.
Intensity data were empirically corrected for absorption with ψ-scan
data. All structures were solved by direct methods. All non-
hydrogen atoms were refined anisotropically. All hydrogen atoms
were generated in ideal positions and refined in a riding mode. All
calculations were carried out with the use of the SHELX-97
programs.15
[Pt(SiHPh2)2(PEt3)2] (0.608 g, 0.762 mmol). After it was stirred
for 18 h at room temperature, the reaction mixture was completely
evaporated under vacuum, and the resulting oily residue was
solidified with diethyl ether. The solids were filtered and washed
with hexane (2 × 2 mL). Recrystallization with ether/CH2Cl2 (5:
1) gave white crystals of [Pt(S2SiPh2)(PEt3)2], (6; 0.160 g, 31%).
1H NMR (CDCl3, δ): 1.13 (qt, J ) 7.5, 16 Hz, 18H, P(CH2CH3)3),
2.00 (m, 12H, P(CH2CH3)3), 7.28-7.32 (m, 6H, Ph), 7.78-7.81
(m, 4H, Ph). 13C{1H} NMR (CDCl3): 8.28 (s, JPt-C ) 24 Hz,
P(CH2CH3)3), 16.3 (d, JC-P ) 36 Hz, JPt-C ) 26 Hz, P(CH2CH3)3),
127.2, 128.5, 133.4, 144.9. 31P{1H} NMR (CDCl3): 7.14 (s, JPt-P
) 3076 Hz). Anal. Calcd for C24H40P2S2SiPt: C, 42.53; H, 5.95.
Found: C, 42.92; H, 5.81.
Acknowledgment. This work was supported by the
research fund (2007) of Kangnung National University and
partly by a Korea Research Foundation Grant funded by the
Korean Government (MOEHARD, Basic Research Promo-
tion Fund; No. KRF-2007-521-C00148).
Similar treatments with p-tolylNCS also gave complex 6.
Preparation of Complexes 7 and 8. THF (3 mL) and p-
tolylNCS (0.114 g, 0.764 mmol) were added to a Schlenk flask
containing [Pt(SiHPh2)2(PMe2Ph)2] (0.320 g, 0.382 mmol). After
it was stirred for 40 h at room temperature, the reaction mixture
was completely evaporated under vacuum, and then the resulting
oily residue was solidified with ether/CH2Cl2 (10:1). The solids
were filtered and washed with hexane (2 × 2 mL). Recrystallization
with ether/CH2Cl2 (5:1) gave pale yellow crystals of [Pt-
Supporting Information Available: CIF files giving crystal-
lographic data for complexes 1, 4, 6, and 7. This material is
available free of charge via the Internet at http://pubs.acs.org.
OM8006079
(15) Sheldrick, G. M. SHELX-97; University of Go¨ttingen, Go¨ttingen,
Germany, 1997.