Double insertion of carbon bisulfide into Pb-S bonds of lead(II) bis(arenethiolate): Synthesis and crystal structure of lead(II) bis(aryl trithiocarbonate)

Article abstract of DOI:10.1021/om970861p

The first lead(II) bis(aryl trithiocarbonate) compounds, (ArSCS₂)₂Pb (2a, Ar = Bbt (Bbt = 2,6-bis-[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]-phenyl); 2b, Ar = Tbt (Tbt = 2,4,6-tris[bis(trimethylsilyl)-methyl]phenyl)),

Full text of DOI:10.1021/om970861p

Organometallics 1998, 17, 1241-1244
1241
Dou ble In ser tion of Ca r bon Disu lfid e in to P b-S Bon d s of
Lea d (II) Bis(a r en eth iola te): Syn th esis a n d Cr ysta l
Str u ctu r e of Lea d (II) Bis(a r yl tr ith ioca r bon a te)
Naokazu Kano, Norihiro Tokitoh,* and Renji Okazaki*
Department of Chemistry, Graduate School of Science, The University of Tokyo,
7-3-1 Hongo, Bunkyo-ku, Tokyo 113, J apan
Received October 3, 1997
Sch em e 1
Summary: The first lead(II) bis(aryl trithiocarbonate)
compounds, (ArSCS2)2Pb (2a , Ar ) Bbt (Bbt ) 2,6-bis-
[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]-
phenyl); 2b, Ar ) Tbt (Tbt ) 2,4,6-tris[bis(trimethylsilyl)-
methyl]phenyl)), were obtained by reaction of the corre-
sponding lead(II) bis(arenethiolate) species, (ArS)2Pb:
(1) with carbon disulfide. The crystal structure of 2a ‚
CH2Cl2 was established by X-ray crystallographic analy-
sis. The formation of 2 can be rationalized in terms of
double insertion of carbon disulfide into two lead-sulfur
bonds of 1.
an interesting reaction of decamethylsilicocene, (Me5C5)2-
Si, with carbon disulfide to form an unexpected dithia-
disiletane derivative.5
In tr od u ction
The chemistry of divalent group 14 element com-
pounds has stimulated wide interest.1 In contrast to
divalent silicon, germanium, and tin species, which have
been extensively studied, the corresponding lead species
(plumbylenes) have been much less explored. Among
plumbylenes, lead(II) dithiolates, (RS)2Pb, have received
attention,2 but only a few of their reactions have been
reported to date.2a In the course of our work on the
heavier congeners of carbenes, in which we have been
taking advantage of kinetic stabilization afforded by an
efficient steric protection group, 2,4,6-tris[bis(trimeth-
ylsilyl)methyl]phenyl (denoted as Tbt),3 we recently
reported that the reactions of Tbt(R)M: (M ) Si, Ge,
Sn) with carbon disulfide give different types of adducts
depending on M.4 J utzi and co-workers also reported
We are interested in the difference in reactivity
among the group 14 elements and have carried out
reactions of lead(II) bis(arenethiolate) compounds,
(ArS)2Pb (1), with carbon disulfide and have discovered
that the double-insertion reaction of carbon disulfide
into Pb-S bonds occurs, giving the first lead(II) bis(aryl
trithiocarbonate) compounds, 2a and 2b (Scheme 1). We
also describe the X-ray crystallographic analysis of 2a .
In connection with our previous work,3 extremely bulky
groups, 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimeth-
ylsilyl)methyl]phenyl (denoted as Bbt) and Tbt, were
employed as aryl groups.6
(1) For reviews, see: (a) Raabe, G.; Michl, J . Chem. Rev. (Washing-
ton, D.C.) 1985, 85, 419. (b) Petz, W. Chem. Rev. (Washington, D.C.)
1986, 86, 1019. (c) Lappert, M. F.; Rowe, R. S. Coord. Chem. Rev. 1990,
100, 267. (d) Barrau, J .; Escudie´, J .; Satge´, J . Chem. Rev. (Washington,
D.C.) 1990, 90, 283. (e) Neumann, W. P. Chem. Rev. (Washington, D.C.)
1991, 91, 311. (f) Tsumuraya, T.; Batcheller, S. A.; Masamune, S.
Angew. Chem., Int. Ed. Engl. 1991, 30, 902. (g) Driess, M.; Gru¨tzma-
cher, H. Angew. Chem., Int. Ed. Engl. 1996, 35, 828.
(2) (a) Shaw, R. A.; Woods, M. J . Chem. Soc. A 1971, 1569. (b)
Hitchcock, P. B.; Lappert, M. F.; Samways, B. J .; Weinberg, E. L. J .
Chem. Soc., Chem. Commun. 1983, 1492. (c) Hammel, H.-U.; Meske,
H. Z. Naturforsch. 1988, 43B, 389. (d) Brooker, S.; Buijink, J .-K.;
Edelmann, F. T. Organometallics 1991, 10, 25.
Resu lts a n d Discu ssion
Lead(II) bis(arenethiolate) 1 (1a , Ar ) Bbt; 1b, Ar )
Tbt) was prepared in situ as a dark red solution by the
nucleophilic substitution of a lead(II) diamide, [(Me3-
Si)2N]2Pb,8 with 2 equiv of ArSLi in ether at -40 °C.
(3) (a) Tokitoh, N.; Suzuki, H.; Okazaki, R. J . Am. Chem. Soc. 1993,
115, 10428. (b) Tokitoh, N.; Suzuki, H.; Okazaki, R. Organometallics
1994, 13, 167. (c) Suzuki, H.; Tokitoh, N.; Okazaki, R. J . Am. Chem.
Soc. 1994, 116, 11572. (d) Suzuki, H.; Tokitoh, N.; Okazaki, R. J . Am.
Chem. Soc. 1994, 116, 11578. (e) Tokitoh, N.; Kano, N.; Shibata, K.;
Okazaki, R. Phosphorus, Sulfur Silicon Relat. Elem. 1994, 93-94, 189.
(f) Tokitoh, N.; Kano, N.; Shibata, K.; Okazaki, R. Organometallics
1995, 14, 3121. (g) Suzuki, H.; Tokitoh, N.; Okazaki, R. Bull. Chem.
Soc. J pn. 1995, 68, 2471. (h) Tokitoh, N.; Kishikawa, K.; Matsumoto,
T.; Okazaki, R. Chem. Lett. 1995, 827. (i) Saito, M.; Tokitoh, N.;
Okazaki, R. Chem. Lett. 1996, 265. (j) Kishikawa, K.; Tokitoh, N.;
Okazaki, R. Chem. Lett. 1996, 695. (k) Tokitoh, N.; Kishikawa, K.;
Manmaru, K.; Okazaki, R. Heterocycles 1997, 44, 149. (l) Takeda, N.;
Suzuki, H. Tokitoh, N.; Okazaki, R.; Nagase, S. J . Am. Chem. Soc.
1997, 119, 1456.
(4) (a) Tokitoh, N.; Suzuki, H.; Okazaki, R. Chem. Commun. 1996,
125. (b) Tokitoh, N.; Kishikawa, K.; Okazaki, R. J . Chem. Soc., Chem.
Commun. 1995, 1425. (c) Saito, M.; Tokitoh, N.; Okazaki, R. Organo-
metallics 1995, 14, 3620.
(5) (a) J utzi, P.; Eikenberg, D.; Mo¨hrke, A.; Neumann, B.; Stammler,
H.-G. Organometallics 1996, 15, 753. (b) J utzi, P.; Mo¨hrke, A. Angew.
Chem., Int. Ed. Engl. 1989, 28, 762.
(6) BbtLi was prepared by the reaction of BbtBr with t-BuLi. BbtBr
was synthesized similarly to TbtBr.7 The synthetic procedure and
chemical properties of BbtBr will be published elsewhere: Unno, M.
Dissertation, The University of Tokyo, 1988.
(7) (a) Auner, A.; Klingebiel, U. In Synthetic Methods of Organo-
metallic and Inorganic Chemistry; Herrmann, W. A., Ed.; Georg
Thieme Verlag: Stuttgart, Germany, 1996; Vol. 2, p 260. (b) Okazaki,
R.; Unno, M.; Inamoto, N. Chem. Lett. 1987, 2293.
S0276-7333(97)00861-3 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 02/05/1998

1242 Organometallics, Vol. 17, No. 6, 1998
Notes
Ta ble 1. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for (BbtSCS2)2P b‚CH2Cl2
(a) Bond Distances
Pb(1)-S(2)
Pb(1)-S(3)
Pb(1)-S(5)
Pb(1)-S(6)
C(10)-S(1)
C(10)-S(2)
2.883(7)
2.673(7)
2.850(6)
2.669(6)
1.783(20)
1.647(18)
C(10)-S(3)
C(41)-S(4)
C(41)-S(5)
C(41)-S(6)
C(1)-S(1)
1.693(18)
1.756(18)
1.631(19)
1.695(19)
1.810(18)
1.812(17)
C(32)-S(4)
(b) Bond Angles
S(3)-Pb(1)-S(6)
S(3)-Pb(1)-S(5)
S(5)-Pb(1)-S(6)
S(2)-Pb(1)-S(6)
S(2)-Pb(1)-S(5)
S(2)-Pb(1)-S(3)
S(1)-C(10)-S(3)
95.8(2)
82.2(2)
64.2(2)
81.5(2)
129.1(2)
64.2(2)
S(1)-C(10)-S(2)
S(2)-C(10)-S(3)
S(4)-C(41)-S(5)
S(4)-C(41)-S(6)
S(5)-C(41)-S(6)
C(1)-S(1)-C(10)
C(32)-S(4)-C(41)
123.2(11)
124.8(13)
123.7(12)
112.1(11)
124.0(11)
106.0(8)
111.9(11)
106.0(9)
ture. The two carbon atoms of the bidentate ligands
are trigonal planar, and the C-S bond lengths (1.631-
(19)-1.695(19) Å) in each trithiocarbonate ligand are
between the sums of covalent bond radii of single (1.81
Å) and double bonds (1.62 Å), even when the large
standard deviations are taken into account.10 On the
other hand, one Pb-S bond (2.669(6) or 2.673(7) Å) is
significantly shorter than the other one (2.850(6) or
2.883(7) Å) in each ligand, although both Pb-S bond
lengths are longer than the sum of the covalent bond
radii of Pb and S (2.50 Å).10 Two sulfur atoms of the
thiocarbonyl units, S(2) and S(5), are located on different
sides of the plane that contains the central lead atom
and the other two sulfur atoms S(1) and S(4). These
configurations are most reasonably interpreted in terms
of one strong and one weak coordination bond between
the S atoms of the trithiocarbonate ligand and Pb.
Although there are some PbIIS4 complexes chelated by
two sets of sulfur ligands, such as lead(II) bis(dithio-
carbonate),11 lead(II) bis(dithiocarbamate),12 and lead-
(II) bis(dithiophosphate),13 complex 2a is, to our knowl-
edge, the first example of crystallographically analyzed
lead(II) bis(trithiocarbonate). Moreover, its unique
synthetic method is worthy of note; the above-mentioned
PbIIS4 compounds usually were synthesized by nucleo-
philic attack of the corresponding alkali-metal salts on
lead(II) compounds.
F igu r e 1. ORTEP drawing of 2a ‚CH2Cl2 with thermal
ellipsoid plot (30% probability). The dichloromethane mol-
ecule was omitted for clarity.
Although 1 was not isolated, its characteristic absorp-
tion for 1b (λmax 538 nm in hexane) was observed in the
electronic spectrum as in the cases of other plumby-
lenes.9 After the reaction mixture was warmed to room
temperature, an excess of carbon disulfide was added
to give the lead(II) bis(aryl trithiocarbonate) (2a , 68%;
2b, 66%) as stable yellow crystals (Scheme 1). Com-
plexes 2a and 2b were found to be stable to air and
moisture at room temperature.
1
The structures of 2a and 2b were determined by H,
13C, and 207Pb NMR, elemental analysis, and FAB mass
spectroscopy. Since their 1H and 13C NMR spectra
showed one set of signals due to Bbt or Tbt groups, the
two sets of trithiocarbonate ligands are considered to
be equivalent in solution at room temperature. The
structure of 2a was established by X-ray crystallography
for a crystal of modest quality obtained from a dichlo-
romethane-ethanol solution. The ORTEP drawing of
2a ‚CH2Cl2 is shown in Figure 1. Selected bond dis-
tances and bond angles are given in Table 1. Lead(II)
bis(aryl trithiocarbonate) 2a exists as a monomer, and
there is no intermolecular interaction between lead and
sulfur atoms. The lead atom is surrounded by four
intramolecular sulfur atoms of two bidentate trithio-
carbonate ligands. The configuration around the lead
atom is best described as a distorted-pyramidal struc-
The fact that 2 bears two trithiocarbonate ligands on
the lead atom indicates the presence of some insertion
process of carbon disulfide in its formation from 1. We
propose the mechanism shown in Scheme 2 for the
formation of 2. Complex 1 first interacts with carbon
disulfide to form the ylide 3, as we suggested previously
in the reaction of germylene and stannylene.4 An
arylthio group subsequently migrates from lead to the
ylidic carbon atom to give the intermediary lead(II)
(10) Shriver, D. F.; Atkins, P. W.; Langford, C. H. Inorganic
Chemistry; Oxford University Press: Oxford, U.K., 1994; p 58.
(11) (a) Hagihara, H.; Yamashita, S. Acta Crystallogr. 1966, 21, 350.
(b) Hagihara, H.; Watanabe, Y.; Yamashita, S. Acta Crystallogr. 1968,
B24, 960. (c) Hagihara, H.; Yoshida, N.; Watanabe, Y. Acta Crystallogr.
1969, B25, 1775. (d) Tieknik, E. R. T. Acta Crystallogr. 1988, C44,
250.
(12) (a) Iwasaki, H.; Hagihara, H. Acta Crystallogr. 1972, B28, 507.
(b) Potenza, J .; Mastropaolo, D. Acta Crystallogr. 1973, B29, 1830. (c)
Ito, M.; Iwasaki, H. Acta Crystallogr. 1980, B36, 443. (d) Iwasaki, H.
Acta Crystallogr. 1980, B36, 2138. (e) Hummel, H.-U.; Meske, H. J .
Chem. Soc., Dalton Trans. 1989, 627. (f) Caruso, F.; Chan, M.-L.; Rossi,
M. Inorg. Chem. 1997, 36, 3609.
(13) (a) Ito, T. Acta Crystallogr. 1972, B28, 1034. (b) Harrison, P.
G.; Steel, A.; Pelizzi, G.; Pelizzi, C. Main Group Met. Chem. 1988, 11,
181.
(8) Gynane, M. J . S.; Harris, D. H.; Lappert, M. F.; Power, P. P.;
Rivie`re, P.; Rivie`re-Baudet, M. J . Chem. Soc., Dalton Trans. 1977,
2004.
(9) (a) Klinkhammer, K. W.; Schwartz, W. Angew. Chem., Int. Ed.
Engl. 1995, 34, 1334. (b) Driess, M.; J anoschek, R.; Pritzkow, H.; Rell,
S.; Winkler, U. Angew. Chem., Int. Ed. Engl. 1995, 34, 1614. (c) Simons,
R. S.; Pu, L.; Olmstead, M. M.; Power, P. P. Organometallics 1997,
16, 1920.

Notes
Organometallics, Vol. 17, No. 6, 1998 1243
BbtBr (1.41 g, 2.00 mmol) and a hexane solution of t-BuLi (1.60
M, 2.80 mL) at -72 °C, was added elemental sulfur (641 mg,
2.50 mmol) at -72 °C. After the mixture was gradually
warmed to the room temperature, a 10% aqueous NaOH
solution of pottasium ferricyanide was added to the reaction
mixture at room temperature. After it was stirred for 5 h,
the reaction mixture was separated. The aqueous phase was
extracted with ether, and the extract was then combined with
the organic phase. The combined solution was dried with
anhydrous MgSO4 and evaporated to give a yellow solid.
Separation of the crude solid with preparative HPLC afforded
BbtS4Bbt (897 mg, 65%) as a pale yellow solid. BbtS4Bbt:
Sch em e 2
1
yellow crystals, mp 276-281 °C; H NMR (500 MHz, CDCl3)
δ 0.09 (s, 72H), 0.26 (s, 54H), 3.22 (s, 4H), 6.87 (s, 4H); 13C
NMR (125 MHz, CDCl3) δ 1.26 (q), 5.27 (q), 22.77 (s), 28.74
(d), 126.75 (d), 130.65 (s), 147.12 (s), 150.19 (s); HRMS (FAB)
found m/z 1375.6138, calcd for C60H135S4Si14 ([M + H]+)
1375.6217. Anal. Calcd for C60H134S4Si14: C, 52.32; H, 9.81;
S, 9.31. Found: C, 52.21; H, 9.49; S, 9.49.
compound 4, which further reacts with another carbon
disulfide molecule to give the final product 2 by repeat-
ing a similar insertion process.
Although the migratory insertion of carbon disulfide
into a metal-sulfur bond is known for some transition-
metal complexes,14 such double insertion of carbon
disulfide as suggested above for 2 has not been observed
in the case of other heavier group 14 element divalent
compounds, R1(R2)M: (M ) Si, Ge, Sn).4,5 Interestingly,
the reaction of the aryl(arylthio)plumbylene Tbt(TbtS)-
Pb: (5)15 with carbon disulfide also gave 2b in 20% yield
together with TbtSH (16%) and TbtH (18%).16 Although
the reaction mechanism is unclear at present, the reac-
tion must involve not only the insertion of carbon disul-
fide into the Pb-S bond but also the formal insertion
of a sulfur atom into the Pb-C(Tbt) bond followed by
reaction with carbon disulfide. Further work is in prog-
ress to elucidate a detailed mechanism for this interest-
ing reaction.
Syn th esis of 2,6-Bis[bis(tr im eth ylsilyl)m eth yl]-4-[tr is-
(tr im eth ylsilyl)m eth yl]-1-m er ca p toben zen e, BbtSH. To
a THF solution (30 mL) of BbtS4Bbt (860 mg, 0.625 mmol) was
added LiAlH4 (100 mg, 2.65 mmol) at 0 °C. After it was stirred
at room temperature for 1 h, the reaction mixture was further
refluxed for 8 h. After being poured into ice-cooled dilute
aqueous HCl, the organic phase was separated, and the
aqueous phase was extracted with hexane. The combined
solution was dried with anhydrous MgSO4 and evaporated to
give a white solid. Separation of the crude solid with prepara-
tive HPLC afforded BbtSH (657 mg, 80%) as a colorless solid.
BbtSH: colorless crystals, mp 158-161 °C; 1H NMR (500 MHz,
CDCl3) δ 0.03 (s, 36H), 0.24 (s, 27H), 2.47 (s, 1H), 3.04 (s, 2H),
6.82 (s, 2H); 13C NMR (125 MHz, CDCl3) δ 0.95 (q), 5.23 (q),
21.68(s), 28.86 (d), 123.33 (s), 126.52 (d), 142.88 (s), 146.65 (s);
HRMS (FAB) found m/z 656.3427, calcd for C30H68SSi7 ([M]+)
656.3494. Anal. Calcd for C30H68SSi7: C, 54.80; H, 10.42; S,
4.88. Found: C, 54.91; H, 10.21; S, 4.70.
Exp er im en ta l Section
Syn th esis of Lea d (II) Bis{2,6-bis[bis(tr im eth ylsilyl)-
m eth yl]-4-[tr is(tr im eth ylsilyl)m eth yl]p h en yl tr ith ioca r -
bon a te} (2a ). An ether solution (5 mL) of BbtSLi, which was
prepared from BbtSH (329 mg, 0.501 mmol) and a pentane
solution of n-BuLi (1.64 M, 0.32 mL) at -72 °C, was added to
an ether solution (5 mL) of [(Me3Si)2N]2Pb (130 mg, 0.246
mmol) at -60 °C. After the reaction mixture was gradually
warmed to room temperature, carbon disulfide (0.30 mL, 4.99
mmol) was added to it. After it was stirred for 30 min, the
reaction mixture was filtered to remove insoluble materials
with Celite. The filtrate was evaporated to give a reddish oil.
Separation of the crude oil with silica gel chromatography
afforded 2a (281 mg, 68%) as a yellow solid. 2a : yellow
crystals, mp 230-239 °C dec; 1H NMR (500 MHz, CDCl3) δ
0.03 (s, 36H), 0.13 (s, 36H), 0.26 (s, 54H), 2.56 (s, 4H), 6.85 (s,
4H); 13C NMR (125 MHz, CDCl3) δ 1.24 (q), 2.11 (q), 5.27 (q),
22.57 (s), 27.82 (d), 127.04 (s), 127.28 (d), 147.69 (s), 149.52
(s), 242.18 (s); 207Pb NMR (105 MHz, CDCl3) δ 1087 (br s);
HRMS (FAB) found m/z 1671.5502, calcd for C62H135S6Si14Pb
([M + H]+) 1671.5424. Anal. Calcd for C62H134S6Si14Pb: C,
44.52; H, 8.08; S, 11.50. Found: C, 44.22; H, 7.85; S, 11.65.
Syn th esis of Lea d (II) Bis{2,4,6-tr is[bis(tr im eth ylsilyl)-
m eth yl]p h en yl tr ith ioca r bon a te} (2b). An ether solution
(4 mL) of TbtSLi, which was prepared from TbtSH (227 mg,
0.388 mmol) and an ether solution of MeLi (1.09 M, 0.37 mL)
at -72 °C, was added to an ether solution (4 mL) of [(Me3-
Si)2N]2Pb (100 mg, 0.189 mmol) at -40 °C. After the reaction
mixture was gradually warmed to room temperature, carbon
disulfide (0.23 mL, 3.8 mmol) was added to it. After it was
stirred for 30 min, the reaction mixture was filtered to remove
insoluble materials with Celite. The filtrate was evaporated
to give a yellow solid. Separation of the crude solid with silica
gel chromatography afforded 2b (196 mg, 66%) as a yellow
solid. 2b: pale yellow crystals, mp 216-224 °C dec; 1H NMR
All experiments were performed under an argon atmosphere
unless otherwise noted. Solvents and carbon disulfide were
dried by standard methods and freshly distilled prior to use.
1H (500 MHz), 13C (125 MHz), and 207Pb (105 MHz) NMR
spectra were recorded on a J EOL R-500 MHz spectrometer at
27 °C. Chemical shifts were measured with tetramethylsilane
as an internal standard for 1H and 13C NMR and with
tetramethylplumbane for 207Pb NMR as an external standard.
High-resolution mass spectral data were obtained on a J EOL
SX-102 mass spectrometer. Preparative HPLC was performed
on an LC-908 (J apan Analytical Industry Co., Ltd.) equipped
with J AI-gel 1H and 2H columns (eluent: toluene). All
melting points were determined on a Yanaco micro melting
point apparataus and are uncorrected. Elemental analyses
were carried out at the Microanalytical Laboratory of the
Department of Chemistry, Faculty of Science, The University
of Tokyo. 1-Bromo-2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]benzene (BbtBr),6 2,4,6-tris[bis(tri-
methylsilyl)methyl]-1-mercaptobenzene (TbtSH),15 bis[bis(tri-
methylsilyl)amino]lead(II) ([(Me3Si)2N]2Pb),8 and {2,4,6-tris-
[bis(trimethylsilyl)methyl]phenyl}{[2,4,6-tris[bis(trimethylsilyl)-
methyl]phenyl]thio}plumbylene (Tbt(TbtS)Pb)15 were prepared
according to the procedures reported in the literature.
Syn th esis of 2,6-Bis[bis(tr im eth ylsilyl)m eth yl]-4-[tr is-
(tr im eth ylsilyl)m eth yl]p h en yl Tetr a su lfid e, BbtS4Bbt. To
an ether solution (5 mL) of BbtLi, which was prepared from
(14) For reviews, see: (a) Pandey, K. K. Coord. Chem. Rev. 1995,
140, 37. (b) Lappert, M. F.; Prokai, B. Adv. Organomet. Chem. 1967,
5, 225.
(15) Kano, N.; Tokitoh, N.; Okazaki, R. Organometallics 1997, 16,
4237.
(16) Reaction of the diarylplumbylene Tbt2Pb: with excess carbon
disulfide gave a complex mixture. No product bearing both Tbt groups
and a lead atom has been identified so far.

1244 Organometallics, Vol. 17, No. 6, 1998
Notes
(500 MHz, CDCl3) δ 0.00 (s, 36H), 0.05 (s, 36H), 0.11 (s, 36H),
1.37 (s, 2H), 2.37 (br s, 4H), 6.36 (br s, 2H), 6.52 (br s, 2H);
13C NMR (125 MHz, CDCl3) δ 0.21 (q), 0.75 (q), 1.71 (q), 26.93
(d), 30.96 (d), 122.58 (d), 124.87 (s), 127.46 (d), 146.21 (s),
149.55 (s), 242.95 (s); 207Pb NMR (105 MHz, CDCl3) δ 1115
0.082 (0.065) with GOF ) 2.23. All calculations were per-
formed using the TEXSAN crystallographic software package
of Molecular Structure Corp.
Rea ction of 5 w ith Ca r bon Disu lfid e. To a THF solution
(2 mL) of Tbt(TbtS)Pb (21.6 mg, 0.0161 mmol) was added
carbon sulfide (30 mL, 0.50 mmol) at room temperature. After
degassing and sealing, the reaction mixture was stirred at
room temperature for 8 h and further refluxed for 2 h. The
reaction mixture was filtered with Celite to remove insol-
uble materials, giving a yellow solid after evaporation. Sepa-
ration of the crude solid with silica gel chromatography
afforded 2b (4.9 mg, 20%), TbtSH (3.0 mg, 16%), and TbtH
(3.2 mg, 18%).
(br s); HRMS (FAB) found m/z 1526.4343, calcd for C56H118
-
S6Si12Pb ([M]+) 1526.4556. Anal. Calcd for C56H118S6Si12Pb:
C, 44.01; H, 7.78; S, 12.59. Found: C, 44.14; H, 7.58; S, 12.32.
Cr ysta l Str u ctu r e Da ta for 2a ‚CH2Cl2. Yellow prismatic
crystals of 2a ‚CH2Cl2 were grown by the slow evaporation of
its saturated solution in ethanol and dichloromethane at room
temperature. 2a ‚CH2Cl2: C63H136Cl2PbS6Si14, FW ) 1757.43,
triclinic, space group P1h (No. 2), a ) 18.764(5) Å, b ) 21.375-
(5) Å, c ) 12.292(2) Å, R ) 91.59(2)°, â ) 95.85(2)°, γ ) 79.23-
(2)°, V ) 4817(1) Å3, Z ) 2, Dcalcd ) 1.211 g cm-3, µ(Mo KR) )
21.45 cm-1, F(000) ) 1844. A yellow prismatic crystal of
2a ‚CH2Cl2 having dimensions of 0.65 × 0.15 × 0.15 mm was
mounted on a glass fiber. The data set was collected on a
Rigaku AFC5R diffractometer with graphite-monochromated
Mo KR radiation (λ ) 0.710 69 Å) at 296 K and a rotating
anode generator. The structure was solved by heavy-atom
Patterson methods (SAPI).17 The intensities were corrected for
Lorentz and polarization effects. The final cycle of full-matrix
least-squares refinement was based on 3961 observed reflec-
tions (I > 3.00σ(I)) and 760 variable parameters and converged
(largest parameter shift was 1.38 times its esd) at R (Rw) )
Ack n ow led gm en t. This work was partially sup-
ported by Grants-in-Aid for Scientific Research Nos.
05236102 and 07454193 from the Ministry of Education,
Science, Sports and Culture of J apan. We are also
grateful to Shin-etsu Chemical Co., Ltd., and Tosoh
Akzo Co., Ltd., for the generous gifts of chlorosilanes
and alkyllithiums, respectively.
Su p p or tin g In for m a tion Ava ila ble: Tables of all bond
lengths and angles, atomic coordinates, and positional and
thermal parameters for 2a ‚CH2Cl2 (44 pages). Ordering
information is given on any current masthead page.
(17) Fan, H.-F. SAPI91, Structure Analysis Programs with Intel-
ligent Control; RIGAKU Corp., Tokyo, J apan, 1991.
OM970861P