Reactivity of bis(silyl) platinum(II) complexes toward isocyanides: Preparation and structure of cis-[Pt(SiHPh2) 2(CNR)(PR′3)] (R = t-Bu, cyclohexyl, i-Pr; R′ = Me, Et)

Article abstract of DOI:10.1021/om030112+

Reactions of organic isocyanides CNR (R = t-Bu, cyclohexyl, i-Pr) with Pt(SiHPh₂)₂(PR′₃)₂ (R′ = Me, Et) gave four novel bis(silyl) platinum(II) complexes Pt(SiHPh ₂)₂(CNR)(PR′₃) containing both phosphine and isocyanide ligands. X-ray crystallographic studies of the two complexes revealed a cis orientation of the diphenylsilyl ligands. Two different Pt-Si bond distances and J(Pt-H) values of the Si-H hydrogen signals strongly suggest a higher trans influence of the silyl ligand relative to the isocyanide.

Full text of DOI:10.1021/om030112+

3316
Organometallics 2003, 22, 3316-3319
Rea ctivity of Bis(silyl) P la tin u m (II) Com p lexes tow a r d
Isocya n id es: P r ep a r a tion a n d Str u ctu r e of
cis-[P t(SiHP h 2)2(CNR)(P R′3)] (R ) t-Bu , cycloh exyl, i-P r ;
R′ ) Me, Et)
Yong-J oo Kim,*,† Eun-Ho Choi,† and Soon W. Lee‡
Department of Chemistry, Kangnung National University, Kangnung 210-702, Korea, and
Department of Chemistry, Sungkyunkwan University, Suwon 440-746, Korea
Received February 19, 2003
Summary: Reactions of organic isocyanides CNR (R )
t-Bu, cyclohexyl, i-Pr) with Pt(SiHPh2)2(PR′3)2 (R′ ) Me,
Et) gave four novel bis(silyl) platinum(II) complexes Pt-
(SiHPh2)2(CNR)(PR′3) containing both phosphine and
isocyanide ligands. X-ray crystallographic studies of the
two complexes revealed a cis orientation of the diphe-
nylsilyl ligands. Two different Pt-Si bond distances and
J (Pt-H) values of the Si-H hydrogen signals strongly
suggest a higher trans influence of the silyl ligand
relative to the isocyanide.
the type Pt(SiHPh)2(PMe3)2 that undergo a facile isomer-
ization between the trans- and cis-isomers.4 Herein we
report the reactions of isocyanides with the bis(silyl)
platinum(II) complexes to afford new Pt(II) complexes
containing two silyl, one phosphine, and one isocyanide
ligand.
Resu lts a n d Discu ssion
Reactions of isocyanides CNR (R ) t-Bu, cyclohexyl,
i-Pr) with Pt(SiHPh2)2(PR′3)2 (R′ ) Me, Et) in THF at
room temperature gave cis-[(SiHPh2)2(CNR)(PR′3)2] (1-
4) as shown in eq 1.
In tr od u ction
Bis(silyl) platinum(II) complexes are important in-
termediates in Pt-catalyzed synthetic reactions such as
the bis-silylation of alkenes or dienes and the dehydro-
coupling of organosilanes, and they also act as useful
starting materials for Si-containing complexes.1-3 Al-
though many interesting reactivities of these complexes
toward unsaturated organic compounds via the Pt-Si
bond cleavage have been reported, the insertion of small
molecules such as CO or isocyanide (CNR) into the Pt-
Si bond in these complexes has been relatively rare.
Thus, we have investigated the reactivity of bis(silyl)
Pt(II) complexes toward isocyanide, which is isoelec-
tronic with CO. We recently synthesized complexes of
Molecular structures of 1 and 3 have been determined
by X-ray diffraction. The crystal data and refinement
data are summarized in Table 1. Figure 1 shows ORTEP
drawings of both complexes, which exhibit a slightly
distorted square-planar coordination, containing one
PMe3, two SiHPh2, and one isocyanide ligand. The
SiHPh2 ligands are located at cis positions, which are
not equivalent. Elongation of the Pt-Si bond trans to
PMe3 (2.378(2) and 2.373(2) Å) compared with those
trans to the isocyanide ligand (2.360(2) and 2.362(2) Å)
can be ascribed to a higher trans influence of the silyl
* Corresponding author. E-mail: yjkim@knusun.kangnung.ac.kr.
Tel: + 82-33-640-2308. Fax: + 82-33-647-1183.
† Kangnung National University.
‡ Sungkyunkwan University.
(1) (a) Chatt, J .; Eaborn, C.; Kapoor, P. N. J . Chem. Soc. (A) 1970,
881. (b) Chatt, J .; Eaborn, C.; Ibekwe, S. D.; Kapoor, P. N. J . Chem.
Soc. (A) 1970, 1343. (c) Eaborn, C.; Metham, T. N.; Pidcock, A. J .
Organomet. Chem. 1977, 131, 377. (d) Kobayashi, T.; Hayashi, T.;
Yamashita, H.; Tanaka, M. Chem. Lett. 1988, 1411. (e) Kobayashi, T.;
Hayashi, T.; Yamashita, H.; Tanaka, M. Chem. Lett. 1989, 467. (f)
Yamashita, H.; Kobayashi, T.; Hayashi, T.; Tanaka, M. Chem. Lett.
1990, 1447. (g) Tanaka, M.; Uchimaru, Y.; Lautenschlager, H.-J .
Organometallics 1991, 10, 16. (h) Grundy, S. L.; Holmes-Smith, R. D.;
Stobart, S. R.; Williams, M. A. Inorg. Chem. 1991, 30, 3333. (i)
Yamashita, H.; Tanaka, M.; Goto, M. Organometallics 1992, 11, 3227.
(j) Heyn, R. H.; Tilley, T. D. J . Am. Chem. Soc. 1992, 114, 1917. (k)
Michalczyk, M. J .; Recatto, C. A.; Calabrese, J . C.; Fink, M. J . J . Am.
Chem. Soc. 1992, 114, 7955. (l) Sakaki, S.; Ieki, M. J . Am. Chem. Soc.
1993, 115, 2373. (m) Ozawa, F.; Kamite, J . Organometallics 1997, 17,
55630. (n) Ozawa, F. J . Organomet. Chem. 2000, 611, 332. (o) Gehrhus,
B.; Hitchcock, P. B.; Lappert, M. F.; Maciejewski, H. Organometallics
1997, 17, 55599. (p) Kang, Y.; Kang, S. O.; Ko, J . Organometallics 1999,
18, 1818. (q) Kalt, D.; Schubert, U. Inorg. Chim. Acta 2000, 301, 211.
(r) Tanabe, M.; Osakada, K. J . Am. Chem. Soc. 2002, 124, 4550.
(2) Reviews: (a) Ojima, I. In The Chemistry of Organic Silicon
Compounds; Patai, S., Rappoport, Z., Eds.; Wiley: New York, 1989;
Chapter 25. (b) Speier, J . L. Adv. Organomet. Chem. 1979, 17, 407. (c)
Cundy, C. S.; Kingston, B. M.; Lappert, M. F. Adv. Organomet. Chem.
1973, 11, 253. (d) Comprehensive Handbook on Hydrosilylation;
Marciniec, B., Ed.; Pergamn Press: Oxford, 1992.
(3) Dinuclear Pt complexes with bridging silyl or silylene ligands:
(a) Auburn, M.; Ciriano, M.; Howard, J . A. K.; Murray, M.; Pugh, N.
J .; Spencer, J . L.; Stone, F. G. A.; Woodward, P. J . Chem. Soc., Dalton
Trans. 1980, 659. (b) Zarate, E. A.; Tessier-Youngs, C. A.; Youngs, W.
J . J . Am. Chem. Soc. 1988, 110, 4068. (c) Zarate, E. A.; Tessier-Youngs,
C. A.; Youngs, W. J . J . Chem. Soc., Chem. Commun. 1989, 577. (d)
Anderson, A. B.; Shiller, P.; Zarate, E. A.; Tessier-Youngs, C. A.;
Youngs, W. J . Organometallics 1989, 8, 2320. (e) Braunstein, P.; Knorr,
M.; Hirle, B.; Reinhard, G.; Schubert, U. Angew. Chem., Int. Ed. Engl.
1992, 31, 1583. (f) Knorr, M.; Braunstein, P.; Tiripicchio, A.; Ugozzoli,
F. Organometallics 1995, 14, 4910. (g) Braunstein, P.; Knorr, M. J .
Organomet. Chem. 1995, 500, 21. (h) Knorr, M.; Hallauer, E.; Huch,
V.; Veith, M.; Braunstein, P. Organometallics 1996, 15, 3868. (i)
Levchinsky, Y.; Rath, N. P.; Braddock-Wilking, J . Organometallics
1999, 18, 2583. (j) Braddock-Wilking, J .; Levchinsky, Y.; Rath, N. P.
Organometallics 2000, 19, 5500. (k) Braddock-Wilking, J .; Levchinsky,
Y.; Rath, N. P. Organometallics 2001, 20, 474. (l) Braddock-Wilking,
J .; Levchinsky, Y.; Rath, N. P. Inorg. Chim. Acta 2002, 330, 82.
(4) Kim, Y.-J .; Park, J .-I.; Lee, S.-C.; Osakada, K.; Tanabe, M.; Choi,
J .-C.; Koizumi, T.; Yamamoto, T. Organometallics 1999, 18, 1349.
10.1021/om030112+ CCC: $25.00 © 2003 American Chemical Society
Publication on Web 06/26/2003

Notes
Organometallics, Vol. 22, No. 16, 2003 3317
Ta ble 1. X-r a y Da ta Collection a n d Str u ctu r e
Refin em en t for 1 a n d 3
formula
fw
temperature, K
cryst syst
space group
a, Å
C
32H40NSi2PPt
C31H38NPSi2Pt
706.86
296(2)
orthorhombic
P212121
10.874(1)
15.871(2)
18.241(2)
720.89
296(2)
monoclinic
P21/n
11.143(1)
16.163(3)
18.231(2)
98.595(6)
3246.6(7)
4
b, Å
c, Å
â, deg
V, Å3
3148.2(6)
4
1.491
4.603
1408
Z
d
cal, g cm-3
1.475
.465
1440
µ, mm-1
F(000)
Tmin
Tmax
0.0269
0.0543
3.5-50
5801
5507
4531
341
1.029
-1.234
1.042
0.1574
0.3358
3.5-50
3538
3453
3258
2θ range (deg)
no. of reflns measd
no. of reflns unique
no. of reflns with I > 2σ(I)
no. of params refined
334
max., in ∆F (e Å-3
)
)
0.862
-0.591
1.020
0.0245
0.0589
min., in ∆F (e Å-3
GOF on F2
R
wR2
0.0355
0.0865
a
wR2 ) ∑[w(Fo - Fc2)2]/∑[w(Fo2)2]1/2
.
a
2
ligand relative to the isocyanide ligand. The Pt-C bond
lengths (1.998(6) for 1 and 2.014(7) Å for 3) are slightly
longer than those found in other platinum-isocyanide
complexes, PtCl2(CNC2H5)[P(C2H5)2C6H5] (1.83(4) Å),5
PtCl2(CNC6H5)2 (1.88(2) and 1.91(2) Å),5 [PtH{(t-Bu)2-
PCH2CH2P(t-Bu)2}(CNAr)]PF6(1.947(8) Å),6 and [Pt-
(CNC6H2-2,4-t-Bu2-6-Me)2Cl]2 (mean 1.95 Å) due to a
high trans influence of the silyl ligand.7 Bond distances
of C28-N1 (1.145(7) Å for 1) and C1-N1 (1.128(8) Å
for 3) are similar to those in PtCl2(CNC6H5)2 (1.19(2)
and 1.14(3) Å)5 and [(6-phenyl-2,2′-terpyridine)Pt(CN-
t-Bu)]ClO4 (1.13(1) Å),8 suggesting the triple-bond char-
acter (CtN) of the isocyanide ligands.
F igu r e 1. (a) ORTEP drawing of 1 showing the atom-
labeling scheme and 50% probability thermal ellipsoids.
Selected bond lengths (Å) and angles (deg): Pt1-C28
1.998(6), Pt1-P1 2.332(2), Pt1-Si2 2.360(2), Pt1-Si1 2.378
(2), Si1-C10 1.893(7), Si1-C4 1.895(6), Si1-Hsi1 1.46(7),
Si2-C16 1.898(7), Si2-C22 1.902(7), Si2-Hsi2 1.48(7),
N1-C28 1.145(7), N1-C29 1.471(8); C28-Pt1-P1 94.7-
(2), C28-Pt1-Si2 175.2(2), P1-Pt1-Si2 89.84(6), C28-
Pt1-Si1 89.6(2), P1-Pt1-Si1 175.63(5), Si2-Pt1-Si1
85.80(6), C10-Si1-C4 108.4(3), Pt1-Si1-Hsi1 119(3),
C16-Si2-C22 109.1(3), C22-Si2-Hsi2 103(3), Pt1-Si2-
Hsi2 107(3), C28-N1-C29 178.1(7), N1-C28-Pt1 179.1-
(5). (b) ORTEP drawing of 3. Selected bond lengths (Å) and
angles (deg): Pt1-C1 2.014(7), Pt1-P1 2.329(2), Pt1-Si1
2.362(2), Pt1-Si2 2.373(2), N1-C1 1.128(8), N1-C2 1.47-
(1), C2-C3 1.45(1), C2-C4 1.48(1); C1-Pt1-P1 95.5(2),
C1-Pt1-Si1 173.4(2), P1-Pt1-Si190.80(6), C1-Pt1-Si2
88.8(2), P1-Pt1-Si2 175.61(6), Si1-Pt1-Si2 84.81(6), C1-
N1-C2 177.7(8), N1-C1-Pt1 176.5(6), C3-C2-N1 110.1-
(9), C3-C2-C4 114.4(10), N1-C2-C4 110.0(8).
All products were obtained as colorless crystals by
recrystallization from diethyl ether or (diethyl ether)/
hexane and characterized by IR, NMR, and elemental
analyses. IR spectra display strong absorption bands at
2165-2172 cm-1 due to ν(NtC) of the C-coordinated
isocyanides and also two bands at 2009-2077 cm-1 due
1
to ν(Si-H). H NMR spectra of 1-4 at -60 °C display
two Si-H signals coupled with a phophine ligand.
Figure 2 shows the Si-H signals of complex 1. The
doublets at 4.98 ppm flanked with Pt satellites (J P-H
)
28 Hz, J Pt-H ) 10 Hz) are assigned to SiH(B) trans to
the PMe3 ligand, whereas the other doublets at 4.67
ppm (J P-H ) 9.6 Hz, J Pt-H ) 120 Hz) are assigned to
SiH(A) on the basis of coupling constants with the
phosphorus of PMe3. The latter signals show a much
higher J Pt-H value than the former. 1H and 31P{1H}
NMR spectra of 1-4 at -60 °C indicate the existence
of only the cis-isomer in solution. Raising the temper-
ature of solutions containing 1-3 to room temperature
results in NMR peak broadening due to cis-trans
isomerism. However, complex 4 retains its NMR spectra
even at room temperature with the negligible peaks
corresponding to the trans-isomer, indicating the cis-
isomer is predominant in solution at least at that
temperature. This phenomenon contrasts with that
previously observed for Pt(SiHPh2)2(PR3) (R ) Me, Et),4
which exhibits a facile cis-trans isomerism on the NMR
time scale in solution. Differences in the cis-trans
(5) (a) J ovanovic´, B.; Manojlovic´-Muir, L.; Muir, K. W. J . Organomet.
Chem. 1971, 33, C75. (b) J ovanovic´, B.; Manojlovic´-Muir, L.; Muir, K.
W. J . Chem. Soc., Dalton Trans. 1972, 1178.
(6) Tanase, T.; Ukaji, H.; Kudo, Y.; Ohno, M.; Kobayashi, K.;
Yamamoto, Y. Organometallics 1994, 13, 1374.
(7) Yamamoto, Y.; Takahashi, K. Yamazaki, H. Chem. Lett. 1985,
201.
(8) Lai, S.-W.; Lam, H.-W.; Cheung, K.-K.; Che, C.-M. Organome-
tallics 2002, 21, 226.

3318 Organometallics, Vol. 22, No. 16, 2003
Notes
(1H, 13C{1H}, and 31P{1H}) spectra were obtained on a J EOL
Lamda 300 MHz spectrometer. Chemical shifts were refer-
enced to internal Me4Si (1H and 13C{1H}) and to external 85%
H3PO4 (31P{1H}). Pt(SiHPh2)2L2 (L ) PMe3, PEt3) complexes
were prepared by the literature method.4
P r ep a r a tion of 1-4. To a Schlenk flask containing Pt-
(SiHPh2)2(PMe3)2 (0.181 g, 0.253 mmol) was added THF (6 mL)
and tert-butyl isocyanide (0.021 g, 0.253 mmol) in that order.
After stirring for 24 h at room temperature, the reaction
mixture was completely evaporated under vacuum, and then
the resulting residue was solidified with hexane at -30 °C.
The solids were filtered and washed with hexane (2 × 2 mL).
Recrystallization from THF/hexane gave white crystals of Pt-
(SiHPh2)2(CN-t-Bu)(PMe3), 1 (0.330 g, 67%).
IR (KBr, cm-1): ν(SiH) 2031, 2071; ν(CN) 2166. 1H NMR
(-60 °C, CDCl3, 300 MHz, δ): 1.27 (s, 9H, CH3), 1.53 (d, J P-H
) 8.8 Hz, J Pt-H ) 20 Hz, 9H, PMe3), 4.67 (d, J P-H ) 9.6 Hz,
J Pt-H ) 120 Hz, 1H, SiH), 4.98 (d, J P-H ) 28 Hz, J Pt-H ) 10
Hz, 1H, SiH), 7.18-7.31 (m, 16H, Ph), 7.61-7.64 (m, 4H, Ph).
13C{1H} NMR (-60 °C, CDCl3, 75 MHz, δ): 15.0 (d, J P-C ) 28
Hz, PMe3), 29.3 (s, CH3), 57.1 (s, C(CH3)3), 126.7, 126.9, 127.2,
135.9 (d, J P-C ) 4.8 Hz, J Pt-C ) 19, Ph), 136.7 (s, J P-C ) 25
Hz, Ph), 141.2 (d, J P-C ) 2.5 Hz, J Pt-C ) 47 Hz, Ph), 143.5 (d,
J P-C ) 5.0 Hz, J Pt-C ) 16, Ph), 145.7, 145.8 (Ph). 31P{1H} NMR
(-60 °C, CDCl3, 120 MHz, δ): -13.8 (s, J Pt-P ) 1594 Hz, J Si-P
) 145 Hz). Anal. Calcd for C32H40NPSi2Pt: C, 53.32; H, 5.59;
N, 1.94. Found: C, 52.94; H, 5.60; N, 1.90.
F igu r e 2. 1H NMR spectrum of 1 (Si-H region) at -60
°C.
isomerism behavior between complexes 1 and 4 seem
to arise from the different steric requirements of the
phosphine ligands (PMe3 in 1 and PEt3 in 4).9 Previ-
ously, Ozawa and co-workers10 reported that CO, which
is isoelectronic with isocyanide, selectively inserted into
the Pt-C bond of alkylsilyl platinum(II) complexes and
proposed the formation of an intermediate of CO-
coordinated Pt(II) complexes. The corresponding iso-
cyanide insertion into the Pt-Si bond does not occur
under our reaction conditions. In fact, CO or CNR
inserion into the Pt-Si bond has never been reported.
Tanaka and co-workers previously reported that bis-
(silyl) Pt(II) complexes reductively eliminated to give a
disilane in the presence of PR3 as a two-electron donor.1d
By contrast, Braddock-Wilking et al. recently showed
that the Pt-Si bond remained intact in the reactions
of R3P-Pt-Si complexes with another PR′3.3i,l
In summary, we synthesized four new unsymmetrical
bis(silyl) platinum(II) complexes {Pt(SiHPh2)2(CNR)-
(PR′3)}, by replacing one phosphine ligand of bis-
(phosphine) platinum complexes with isocyanide, which
might be considered as intermediates in organic sub-
strate insertion into the Pt-Si bond to give organic
silylated compounds. The relative orientation of the two
silyl ligands (that is, cis-trans isomerization) of these
platinum compounds in solution appears to be depend-
ent on temperature and ancillary ligands.
Complexes 2-4 were prepared analogously. Data for 2
(54%). IR (KBr, cm-1): ν(SiH) 2047, 2075; ν(CN) 2172. 1H NMR
(-60 °C, CDCl3, 300 MHz, δ): 1.43-1.90 (br, 11H, C6H11), 1.51
(br, 9H, J ) 9 Hz, PMe3), 4.71 (d, 1H, J ) 9 Hz, 1H, J Pt-C
)
116 Hz, SiH), 4.98 (d, 1H, J ) 27 Hz, J Pt-C ) 27 Hz, SiH),
7.18-7.38 (m, 16H, Ph), 7.58-7.64 (m, 4H, Ph). 13C{1H} NMR
(-60 °C, CDCl3, 75 MHz, δ): 16.2 (d, J Pt-C ) 29 Hz, J Pt-C
29 Hz, PMe3), 24.0, 32.2, 54.4, 66.1 (s, C6H11), 126.8, 126.9,
127.3, 135.9 (d, J Pt-C ) 2 Hz, J Pt-C ) 43 Hz), 136.7 (s, J Pt-C
)
)
25 Hz), 141.3 (d, J Pt-C ) 3 Hz, J Pt-C ) 46 Hz), 143.6 (d, J ) 4
Hz, J Pt-C ) 17 Hz), 141.7 (s, Ph). 31P{1H} NMR (-60 °C, CDCl3,
120 MHz, δ): -14.9 (s, J Pt-C ) 1809 Hz). Anal. Calcd for C34H42
-
NPSi2Pt: C, 54.67; H, 5.67; N, 1.88. Found: C, 54.85; H, 5.73;
N, 1.85.
Data for 3 (71%). IR (KBr, cm-1): ν(SiH) 2012, 2076; ν(CN)
1
2168. H NMR (-60 °C, CDCl3, 300 MHz, δ): 1.19 (d, J H-H
)
6.6 Hz, CH3), 1.50 (d, J P-H ) 8.8 Hz, J Pt-H ) 20 Hz, 9H, PMe3),
4.71 (d, J P-H ) 9.2 Hz, J Pt-H ) 118 Hz, 1H, SiH), 4.92 (s, J Pt-H
) 19 Hz, 1H, SiH), 5.02 (s, J Pt-H ) 25 Hz, 1H, SiH), 7.19-
7.63 (m, 20H, Ph). 13C{1H} NMR (-60 °C, CDCl3, 75 MHz, δ):
16.2 (d, J P-C ) 29 Hz, J Pt-C ) 27 Hz, PMe3), 25.5 (s, CH3),
48.2 (t, J Pt-C ) 8 Hz, CH2), 126.8, 126.9, 127.3, 135.9 (d, J P-C
) 1.2 Hz, J Pt-C ) 19 Hz), 136.7 (s, J Pt-C ) 26 Hz), 141.3 (d,
J P-C ) 2.5 Hz, J Pt-C ) 46 Hz), 143.6 (d, J P-C ) 4.4 Hz, J Pt-C
) 8.4 Hz), 147.0 (d, J P-C ) 46 Hz), 147.2 (d, J P-C ) 1.8 Hz).
31P{1H} NMR (-60 °C, CDCl3, 120 MHz, δ): -13.8 (s, J PtP
)
1604 Hz, J Si-P ) 145, 656 Hz). Anal. Calcd for C31H38NPSi2-
Pt: C, 52.67; H, 5.42; N, 1.98. Found: C, 52.79; H, 5.52; N,
1.97.
Data for 4 (75%). IR (KBr, cm-1): ν(SiH) 2020, 2069; ν(CN),
2166. 1H NMR (25 °C, CDCl3, 300 MHz, δ): 1.05 (q, J P-H
1.8 Hz, 9H, CH2CH3), 1.16 (s, 9H, C(CH3)3), 1.93 (q, J H-H
)
)
Exp er im en ta l Section
7.9 Hz, CH2CH3), 4.72 (d, J P-H ) 9.2 Hz, J Pt-H ) 123 Hz, 1H,
SiH), 5.13 (d, J P-H ) 24 Hz, J Pt-H ) 24 Hz, 1H, SiH), 7.13-
7.57 (m, 20H, Ph). 13C{1H} NMR (-60 °C, CDCl3, 75 MHz, δ):
8.51 (s, J Pt-C ) 18 Hz, P(CH2(CH3)3), 16.3 (d, J P-C ) 25 Hz,
P(CH2(CH3)3), 29.3 (s, C(CH3)3), 58.0 (s, C(CH3)3), 126.7, 126.8,
Gen er a l Meth od s. All manipulations of air-sensitive com-
pounds were performed under N2 or argon with the use of
standard Schlenk line techniques. Solvents were distilled from
Na-benzophenone. The Analytical Laboratory at Kangnung
National University carried out elemental analyses. IR spectra
were recorded on a Perkin-Elmer BX spectrophotometer. NMR
127.1, 136.0 (d, J P-C ) 2 Hz, J Pt-C ) 20 Hz), 136.7 (s, J Pt-C
26 Hz), 141.5 (d, J P-C ) 2 Hz, J Pt-C ) 50 Hz), 143.8 (d, J P-C
)
)
4 Hz, J Pt-C ) 16 Hz), 146.0. 31P{1H} NMR (25 °C, CDCl3, 120
(9) Simons, R. S.; Sanow, L. M.; Galat, K. J .; Tessier, C. A.; Youngs,
W. J . Organometallics 2000, 19, 192.
(10) Ozawa, F.; Hikida, T. Organometallics 1996, 15, 4501.
(11) (a) Sheldrick, G. M. SHELX-97; University of Go¨ttingen:
Germany, 1997. (b) L. J . Farrugia, ORTEP-3 for Windows; University
of Glasgow, 1997.
MHz, δ): 19.0 (s, J Pt-P ) 1631 Hz). Anal. Calcd for C35H46
-
NPSi2Pt: C, 55.10; H, 6.08; N, 1.84. Found: C, 55.50; H, 6.13;
N, 1.73.
Str u ctu r e Deter m in a tion . All X-ray data were collected

Notes
Organometallics, Vol. 22, No. 16, 2003 3319
with a Siemens P4 diffractometer equipped with a Mo X-ray
tube and a graphite monochromator. Intensity data were
empirically corrected for absorption with ψ-scan data. Both
structures were sovled by direct methods. All non-hydrogen
atoms were refined anisotropically. The hydrogen atoms
bonded to silicon atoms were located and refined with a fixed
thermal parameter (U ) 0.08 Å2). The remaining hydrogen
atoms were generated in ideal positions and refined in a riding
mode. All calculations were carried out with use of the SHELX-
97 programs.11
plate, of approximate dimensions 0.64 × 0.42 × 0.09 mm3, was
used.
Ack n ow led gm en t. This work was supported by
Grant R05-2002-000-00559-0 from the Basic Research
Program of the Korea Science & Engineering Founda-
tion.
Su p p or tin g In for m a tion Ava ila ble: Crystallographic
data of 1 and 3. This material is available free of charge via
the Internet at http://pubs.acs.org.
A colorless crystal of 1, shaped as a plate, of approximate
dimensions 0.80 × 0.22 × 0.12 mm3, was used for crystal- and
intensity-data collection. A colorless crystal of 3, shaped as a
OM030112+