Synthesis of metallacycles by oxidative addition of Sn-S, Sn-Se, Sn-Te, and Ge-Te containing precursors to platinum(II)

Article abstract of DOI:10.1021/ic980862p

The first metallacycles formed by oxidative addition of tin-sulfur, tin-selenium, tin-tellurium, and germanium-tellurium bonds to platinum(II) are reported. In particular, the ring compounds [(R₂SnE)₃], where R = Me, Ph and E = Se, Te, and the new compound [(Me₂GeTe)₃], react with [PtMe₂(bu₂bpy)] (bu₂bpy = 4,4′-di-tert-butyl-2,2′-bipyridine) to give the new organoplatinum(IV) metallacycles [PtMe₂(R₂SnE)₂(bu₂bpy)] and [PtMe₂(Me₂-GeTe)₂(bu₂bpy)], respectively. The tin-containing metallacycles complexes can undergo exchange of either the R₂Sn or the E groups by reaction with [(R′₂SnE)₃] or [(R′₂SnE)₃], respectively, to give the corresponding new metallacycles of general formula [PtMe₂(R₂SnE-R′₂SnE)(bu₂bpy)] or [PtMe₂(R₂SnE-R₂SnE′)(bu₂bpy)]. The isostructural series of complexes [PtMe₂(Ph₂SnE)₂(bu₂bpy)] with E = S, Se, and Te have been characterized by X-ray structure determinations. It is shown that ¹¹⁹Sn NMR is a useful method of structure determination for these metallacyclic compounds.

Full text of DOI:10.1021/ic980862p

Inorg. Chem. 1999, 38, 2123-2130
2123
Synthesis of Metallacycles by Oxidative Addition of Sn-S, Sn-Se, Sn-Te, and Ge-Te
Containing Precursors to Platinum(II)
Michael C. Janzen, Hilary A. Jenkins, Louis M. Rendina, Jagadese J. Vittal, and
Richard J. Puddephatt*
Department of Chemistry, The University of Western Ontario, London, Ontario, Canada, N6A 5B7
ReceiVed July 22, 1998
The first metallacycles formed by oxidative addition of tin-sulfur, tin-selenium, tin-tellurium, and germanium-
tellurium bonds to platinum(II) are reported. In particular, the ring compounds [(R2SnE)3], where R ) Me, Ph
and E ) Se, Te, and the new compound [(Me2GeTe)3], react with [PtMe2(bu2bpy)] (bu2bpy ) 4,4′-di-tert-butyl-
2,2′-bipyridine) to give the new organoplatinum(IV) metallacycles [PtMe2(R2SnE)2(bu2bpy)] and [PtMe2(Me2-
GeTe)2(bu2bpy)], respectively. The tin-containing metallacycles complexes can undergo exchange of either the
R2Sn or the E groups by reaction with [(R′2SnE)3] or [(R2SnE′)3], respectively, to give the corresponding new
metallacycles of general formula [PtMe2(R2SnE-R′2SnE)(bu2bpy)] or [PtMe2(R2SnE-R2SnE′)(bu2bpy)]. The
isostructural series of complexes [PtMe2(Ph2SnE)2(bu2bpy)] with E ) S, Se, and Te have been characterized by
X-ray structure determinations. It is shown that 119Sn NMR is a useful method of structure determination for
these metallacyclic compounds.
Introduction
Scheme 1
There is current interest in the activation of bonds between
the elements of groups 14 and 16 by oxidative addition to
transition metal complexes, since these reactions constitute a
critical step in stoichiometric or catalytic transformations.1 For
example, it has recently been shown that all M-Te bonds (M
) C in Ph2Te; M ) Si, Ge, and Sn in Me3MTePh) oxidatively
add to platinum(0) complexes such as [Pt(PEt3)4].2,3 In a
preliminary communication, it was shown that a Sn-S bond
of the ring compounds [(R2SnS)3]4 adds to [PtMe2(bu2bpy)], 1,
bu2bpy ) 4,4′-di-tert-butyl-2,2′-bipyridine,5 to give the orga-
noplatinum(IV) metallacycles [PtMe2(R2SnS)2(bu2bpy)] (2 and
3, Scheme 1), which contain the new five-membered PtSnSSnS
ring.6 It is now shown that related reactions occur easily for
ring complexes containing Sn-Se, Sn-Te, or Ge-Te bonds
to give new metallacycles and full details of these and the earlier
reactions are now described. The factors affecting reactivity in
such reactions have been defined, and the series of complexes
(1) For specific applications of (R2SnS)3 in catalytic and stoichiometric
organic synthesis: (a) Mukaiyama, T.; Watanabe, K.; Shiina, I. Chem.
Lett. 1995, 1. (b) Mukaiyama, T.; Shimomura, N. Chem. Lett. 1993,
781. (c) Shimomura, N.; Mukaiyama, T. Chem. Lett. 1993, 1941. (d)
Mukaiyama, T.; Matsutani, T.; Shimomura, N. Chem. Lett. 1993, 1627.
(e) Mukaiyama, T.; Saito, K.; Kitagawa, H.; Shimomura, N. Chem.
Lett. 1994, 789. (f) Mukaiyama, T.; Matsubara, K. Chem. Lett. 1992,
1041. (g) Wada, M.; Wakamori, H.; Hiraiwa, A.; Erabi, T. Bull. Chem.
Soc. Jpn. 1992, 65, 1389. (h) Shcherbakov, V. I.; Grigor’eva, I. K.;
Razuvaev, G. A.; Zakharov, L. N.; Bochkova, R. I. J. Organomet.
Chem. 1987, 319, 41.
(2) Han, L.-B.; Choi, N.; Tanaka, M. J. Am. Chem. Soc. 1997, 119, 1795.
(3) Han, L.-B.; Shimada, S.; Tanaka, M. J. Am. Chem. Soc. 1997, 119,
8133.
(4) For recent work on organometallic chemistry of (R2SnS)3: (a) Stenger,
H.; Schmidt, B. M.; Dra¨ger, M. Organometallics 1995, 14, 4374. (b)
Flo¨ck, O. R.; Dra¨ger, M. Organometallics 1993, 12, 4623. (c) Imrie,
C. Appl. Organomet. Chem. 1993, 7, 181.
[PtMe2(Ph2SnE)2(bu2bpy)] with E ) S, Se, or Te have been
structurally characterized.
Results
(5) Achar, S.; Scott, J. D.; Vittal, J. J.; Puddephatt, R. J. Organometallics
1993, 12, 4592.
(6) Rendina, L. M.; Vittal, J. J.; Puddephatt, R. J. Organometallics 1996,
15, 1749.
The synthesis of the metallacycles containing five-membered
Pt(SnR2ESnR2E) or Pt(GeMe2TeGeMe2Te) rings is depicted in
Scheme 1.
10.1021/ic980862p CCC: $18.00 © 1999 American Chemical Society
Published on Web 04/15/1999

2124 Inorganic Chemistry, Vol. 38, No. 9, 1999
Table 1. Selected 119Sn NMR Data for the Complexes
Janzen et al.
δ
1J
1J
2J
δ
1J
1J
(Sn1) (PtSn) (SnE) (SnSn) (Sn2)
(SnE1)
(SnE2)
2
3
9
4
5
10
6
7
-34.5 12067
-169.1 13344
-32.7 12103
223
188
217
138.1
51.9
51.7
-77.1 11930 841, Se 249
-194.0 13160 921, Se 217
-72.5 11973 794, Se 250
0.2 1106, Se 1497, Se
-60.3 1178, Se 1640, Se
-57.4 1193, Se 1645, Se
-168.1 11600
192 -342.1 2636, Te 3706, Te
-244.3 12746 2248, Te 139 -340.3 2892, Te 4112, Te
11 -160.5 11686 1942, Te 181 -334.5 2891, Te 4101, Te
12
13
14
-41.3 11951
-50.5 11737
-86.0 11686
223
214 -128.4
51.6
1501, Se
3924, Te
238 -193.2 1053, Se 3845, Te
183 -22.3 1669, Se
15b -188.6 13253 905, Se 224 23.6 1215, Se
15a -173.1 13237
Figure 1. 119Sn NMR spectrum of complex 4 in CD2Cl2. For the Sn1
resonance, circles indicate 1J(Sn1Pt) ) 11 940 Hz and crosses indicate
1J(Sn1Se1) ) 841 Hz; for the Sn2 resonance, trianges and squares
The preliminary communication6 reported that the reactions
of [PtMe2(bu2bipy)], 1, with [(R2SnS)3] to give 2 or 3 occur
over a period of several hours in refluxing acetone solution.
The reactions of 1 with [(R2SnSe)3] (R ) Me, Ph)7 to give 4
and 5, respectively, were faster, being complete within 0.5 h in
refluxing acetone solution, and the products were isolated as
air-stable yellow solids (Scheme 1). Similar reactions of 1 with
[(R2SnTe)3] (R ) Me, Ph)7 and [(Me2GeTe)3]8 yielded the new
PtSn2Te2 metallacycles 6 or 7 and the PtGe2Te2 metallacycle 8
but were faster, being complete within seconds at room
temperature in CH2Cl2 solution. These telluride complexes were
isolated as air-sensitive purple (6, 7) or red-black (8) solids in
good yield (Scheme 1). No reaction occurred between 1 and
the ring compounds (Me2GeS)3 and (Me2GeSe)3 in refluxing
acetone. It has been shown earlier9 that Ge-X oxidative
additions to platinum(II) become more favorable thermodynami-
cally and occur faster kinetically in the sequence X ) I > Br
> Cl, and it is likely that a similar series with X ) Te > Se >
S applies in the above reactions. Thus, the oxidative addition
of Ge-S or Ge-Se bonds to platinum(II) are probably
thermodynamically unfavorable and it is likely that Ge-S
addition is both thermodynamically unfavorable and kinetically
slow.9
1
1
indicate the couplings J(Sn2Se2) ) 1497 Hz and J(Sn2Se1) ) 1106
Hz, respectively; the unmarked inner satellites around each resonance
2
are due to J(SnSn) ) 249 Hz.
Figure 2. A view of the molecular structure of complex 4.
Table 2. Selected Bond Distances (Å) and Angles (deg) for
Complexes 2 and 4 (E ) S, Se)
1
The new metallacycles have been characterized by H and,
where appropriate, by 119Sn (Table 1) and 195Pt NMR spectros-
copy. The 119Sn NMR data, summarized in Table 1, are
particularly useful for structure determination of the new
complexes 4-7 since the 119Sn resonance of the Pt-Sn unit
2
4
Pt(1)-Sn(1)
Pt(1)-E(1)
Pt(1)-N(1)
Pt(1)-N(2)
Pt(1)-C(1)
Pt(1)-C(2)
Sn(1)-E(2)
Sn(2)-E(2)
Sn(2)-E(1)
2.552(1)
2.439(3)
2.14(1)
2.21(1)
2.09(1)
2.05(1)
2.435(4)
2.416(4)
2.355(3)
2.5548(5)
2.5493(6)
2.140(4)
2.204(4)
2.072(5)
2.052(5)
2.5645(7)
2.5322(8)
2.4779(7)
1
displays a large value of J(PtSn) in the range 11 599-13 160
1
Hz and, when E ) Se, a single J(SnE) coupling of 841-921
Hz, while the PtESnE unit displays two different 1J(SnE)
couplings when E ) Se or Te (E ) 77Se, 1106, 1178 in 4 and
1497, 1640 Hz in 5; E ) 125Te, 2636, 2892 in 6 and 3706,
4112 Hz in 7; Table 1). In addition, the long-range coupling
2J(SnTePt) ) 66 and 82 Hz was resolved for the â-SnR2
E(1)-Pt(1)-Sn(1)
Pt(1)-Sn(1)-E(2)
Sn(2)-E(2)-Sn(1)
E(1)-Sn(2)-E(2)
Sn(2)-E(1)-Pt(1)
92.74(9)
110.6(1)
100.1(1)
108.9(1)
108.2(1)
92.61(2)
112.23(2)
97.58(2)
109.00(2)
105.91(2)
(7) (a) Blecher, A.; Dra¨ger, M. Angew. Chem., Int. Ed. Engl. 1979, 18,
677. (b) Bahr, S. R.; Boudjouk, P.; McCarthy, G. J. Chem. Mater.
1992, 4, 383. (c) Blecher, A.; Mathiaschi, B.; Mitchell, T. N. J.
Organomet. Chem. 1980, 184, 175. (d) Jones, C. H. W.; Sharma, R.
D.; Taneja, S. P. Canad. J. Chem. 1986, 64, 980. (e) Cauletti, C.;
Grandinetti, F.; Granozzi, G.; Sebald, A.; Wrackmeyer, B. Organo-
metallics 1988, 7, 262. (f) Puff, H.; Breuer, B.; Schuh, W.; Sievers,
R.; Zimmer, R. J. Organomet. Chem. 1987, 332, 279. (g) Batchelor,
R. J.; Einstein, F. W. B.; Jones, C. H. W. Acta Crystallogr., C 1989,
45, 1813. (h) Puff, H.; Bertram, G.; Ebeling, B.; Franken, M.;
Gattermayer, R.; Hundt, R.; Schuh, W.; Zimmer, R. J. Organomet.
Chem. 1989, 379, 235. (i) Shimada, K.; Okuse, S.; Takikawa, Y. Bull
Chem. Soc. Jpn. 1992, 65, 2848.
resonance of complexes 6 and 7, respectively, and the coupling
2J(SnSn) was also resolved in the metallacyclic compounds
(Table 1). A typical 119Sn NMR spectrum is shown in Figure
1. All complexes give two methylplatinum resonances (MePt
trans to N or E) and the methyltin complexes give four MeSn
resonances as expected for the structures shown in Scheme 1.
The complexes 3, 4, 5, and 7 were characterized by X-ray
structure determinations. The structure of 4 is shown in Figure
2 and selected bond distances and angles are in Table 2. The
structure of 7, which is representative of the isostructural series
(8) (a) Schmidt, M.; Ruf, H. J. Inorg. Nucl. Chem. 1963, 25, 557. (b)
Rochow, E. G. J. Am. Chem. Soc. 1948, 70, 1801.
(9) Levy, C. J.; Puddephatt, R. J. J. Am. Chem. Soc. 1997, 119, 10127.

Synthesis of Metallacycles by Oxidative Addition
Inorganic Chemistry, Vol. 38, No. 9, 1999 2125
larger for the methylplatinum groups trans to nitrogen due to
the lower trans influence of the nitrogen donor. The Pt-N
distances trans to tin are in all cases longer than those trans to
methyl, as a result of the very high trans influence of tin. The
crystals of 3, 5, and 7 are isomorphous, and, as expected, the
cell dimensions and volumes follow the sequence E ) Te >
Se > S (Table 4). Complexes 2‚acetone6 and 4‚acetone are also
isomorphous and isostructural.
There is some evidence for reversibility of the oxidative
addition of the Sn-E bonds to platinum(II). Thus, dilute
solutions of 2 in acetone gave detectable amounts of 1, as
detected by its UV-visible spectrum,5 but the degree of
dissociation in more concentrated solutions used for NMR
studies was too low to measure. However, reaction of 2 with
MeI rapidly gave [PtIMe3(bu2bpy)] and [(Me2SnS)3], identified
1
in situ by H NMR, again consistent with reversible reductive
elimination from 2 to regenerate [PtMe2(bu2bpy)], 1, which
reacts very rapidly with MeI to give [PtIMe3(bu2bpy)].
Figure 3. A view of the molecular structure of complex 7. The
structures of complexes 3 and 5 are similar and key bond parameters
are compared for the isostructural series in Table 3.
The complexes 2, 4, and 6 in dichloromethane solution all
give room-temperature emission6 at 650 nm (λexcitation 310 nm)
assigned to an n(E)-π*(bipy) excited state but the intensity of
the emission follows the series E ) S > Se > Te.
Table 3. Selected Bond Parameters for the Isostructural Complexes
3 (E ) S), 5 (E ) Se), and 7 (E ) Te)
complex
3
5
7
New metallacycles 9, 10, or 11 could be generated by reaction
of 2, 4, or 6, respectively, with (Ph2SnE)3 according to Scheme
2. These reactions led to selective replacement of the â-SnMe2
group by Ph2Sn in each case. To obtain complexes 9, 10, and
11 in pure form, it was necessary to monitor the reactions
carefully since reaction for longer periods also led to replace-
ment of the R-SnMe2 group by Ph2Sn to give the corresponding
complex 3, 5, or 7. Reaction between 3, 5, or 7 and (Me2SnE)3
also gave 9, 10, and 11, respectively, although these reactions
occurred more slowly in CH2Cl2 solution. Finally, complexes
9, 10, and 11 were also formed by a redistribution reaction from
equimolar amounts of 2, 4, and 6, with 3, 5, and 7, respectively,
but this reaction was very slow at room temperature. The
structures of 9, 10, and 11 were unambiguously determined from
the NMR spectra. In particular, comparison of the parameters
from the 119Sn NMR spectra (Table 1) with those of the
symmetrical complexes 2, 4, 6 and 3, 5, 7 is definitive. Thus,
Pt-C(1)
2.081(8)
2.070(8)
2.142(6)
2.192(6)
2.558(1)
2.457(2)
2.425(3)
2.406(3)
2.353(2)
2.09(1)
2.05(1)
2.08(2)
2.06(2)
2.13(1)
2.19(1)
2.571(1)
2.719(1)
2.700(2)
2.700(2)
2.681(2)
Pt-C(2)
Pt-N(1)
2.134(8)
2.186(8)
2.566(1)
2.570(1)
2.556(2)
2.528(2)
2.484(1)
Pt-N(2)
Pt-Sn(1)
Pt-E(2)
Sn(1)-E(1)
Sn(2)-E(1)
Sn(2)-E(2)
E(2)-Pt-Sn(1)
E(1)-Sn(1)-Pt
E(1)-Sn(2)-E(2)
Sn(1)-E(1)-Sn(2)
Sn(2)-E(2)-Pt
90.06(6)
112.38(6)
109.73(9)
98.03(9)
89.97(4)
114.32(4)
110.22(5)
95.22(5)
89.51(4)
117.63(5)
110.47(6)
91.65(6)
107.76(9)
105.56(5)
102.79(4)
3, 5, and 7, is shown in Figure 3, and a comparison of selected
bond parameters for 3, 5, and 7 is given in Table 3. The
metallacycles all adopt an envelope conformation with the
platinum atom in the “flap” position, but the fold angle follows
the sequence E ) Te (34°) > Se (32°) > S (30°) for the rare
isostructural series 3, 5, and 7. Within the five-membered ring
of this series, the angle at E(1) is substantially less than at E(2)
and follows the series E ) S > Se > Te, while the angle at
Sn(1) varies markedly as E ) Te > Se > S (Table 3). In contrast
to these observations, the five-membered metallacycles [1,3-
(t-Bu2Sn)3E2] are close to planar.7f Of the nonequivalent Sn-E
distances in 3, 5, and 7, Sn(2)-E(2) is very short compared to
the others and to comparable distances in [(R2SnE)3], 1,3-(t-
Bu2Sn)3E2, and related compounds.7 The short value of Sn(2)-
E(2) and the relatively high angle at E(2) may arise since E(2)
is trans to a methylplatinum group and hence the Pt-E(2) bond
is relatively weak and polar, thus leading to enhanced E(2)Sn-
(2) π-bonding. There is a clear correlation of the Sn-E distances
1
both the 119Sn chemical shifts and J(SnPt) coupling constants
are very different in analogous complexes containing PtSnMe2
or PtSnPh2 groups (Table 1).
New metallacycles were also formed by reaction of 2-6 with
(R2SnE′)3 according to Scheme 3. These reactions occur to give
overall chalcogenide exchange. In most cases, the product
complex contains the heavier, softer chalcogenide directly
bonded to the softer platinum atom (Scheme 3), as expected in
the thermodynamically more stable product. Thus, for example,
complex 13 was formed either from 2 with (Me2SnTe)3 or from
6 with (Me2SnS)3; similar observations were made with respect
to the formation of the methyltin derivatives 12 and 14.
However, an exception was found in the formation of the
diphenyltin derivative 15 since 15a was formed selectively from
5 with (Ph2SnS)3 while the isomer 15b was formed from 3 with
(Ph2SnSe)3; clearly the â-chalcogen atom was replaced as a
result of kinetic control in this case at least. Isomers 15a and
15b do not interconvert over a period of days at room
temperature. Not all possible reactions of this kind were
successful. Thus, the reaction of complex 7 with (Ph2SnTe)3
was unsuccessful since it gave a complex mixture of products
over the time (4 days) needed to give complete consumption
of the starting material 7. In general, it was difficult to separate
the metallacycles 12-14, containing mixed chalcogenide atoms,
from reaction byproducts, and they were not isolated in pure
1
and J(SnE) couplings when E ) Se or Te, and the values of
1J(Sn2E2) appear to be the highest known.7 The ring folding
also leads to a relatively short transannular distance E(2)‚‚‚Sn-
(1) (3.55, 3.63, 3.73 Å for E ) S, Se, Te respectively), perhaps
indicating secondary bonding between these atoms.7 For the
methylplatinum groups trans to E in 3, 5, and 7, the Pt-C
distances [2.08(1), 2.09(1), 2.08(2) Å for E ) S, Se, Te
respectively] and the coupling constants 2J(PtH) (58, 59, 59 Hz
for E ) S, Se, Te respectively) are essentially equal, indicating
very similar trans influences for E ) S, Se, and Te; the Pt-C
2
distances are shorter, and the coupling constants J(PtH) are

2126 Inorganic Chemistry, Vol. 38, No. 9, 1999
Table 4. Crystal Data and Experimental Details
Janzen et al.
complex
4‚acetone
3
5
7
empirical formula
fw
T/°C
C27H48N2O1Pt1Se2Sn2
1007.06
27
C44H50N2PtS2Sn2
1103.46
25
C44H50N2PtSe2Sn2
1197.25
21
C44H50N2PtTe2Sn2
1294.53
21
λ/ Å
0.710 73
P21/n
0.710 73
P21/c
0.710 73
P21/c
0.710 73
P21/c
space group
a/Å
14.574(1)
13.312(1)
19.142(2)
103.78(1)
3606.8(5)
4
1.855
7.281
1912
12.305(1)
16.667(1)
20.999(2)
92.58(1)
4302.3(6)
4
12.372(1)
16.702(2)
21.113(7)
92.26(2)
4359(2)
4
1.824
6.039
2296
12.481(3)
16.848(4)
21.204(5)
92.05(2)
4456(2)
4
1.930
5.558
2440
b/Å
c/Å
â/deg
V/Å3
Z
d(c)/g cm-3
µ/mm-1
F(000)
R [I > 2s(I)]a
R1
1.704
4.524
0.0324
0.0652
0.0402
0.0811
0.0481
0.1036
0.0599
0.1556
wR2
2
a R1 ) ∑(||Fo| - |Fc||)/∑|Fo|; wR2 ) [∑w(Fo - Fc2)2/∑wFo4]1/2
.
Scheme 2
Scheme 3
form but were characterized unambiguously by their rich NMR
spectra (Table 1) using the principles outlined earlier. For
example, in the 119Sn NMR spectrum of complex 12, the Sn1-
Me2 resonance shows no coupling to selenium while the Sn2
resonance shows the large coupling 1J(SnSe) ) 1501 Hz
expected for a PtSeSnMe2 group (Table 1). Similarly, the
isomers 15a and 15b are distinguished inter alia by the
are incorporated into a mixture of organotin metallacycles
including the mixed dimethyltin, diphenyltin derivatives [(Me2-
SnS)(Ph2SnS)2] and [Ph2SnS(Me2SnS)2], identified in the reac-
tion mixtures by their known NMR spectra.4,7 Indeed, the
complex 2 can act as a catalyst for the redistribution reaction
of [(Me2SnS)3] and [(Ph2SnS)3] to give an equilibrium with the
mixed trimeric compounds [Ph2SnS(Me2SnS)2] and [(Me2SnS)-
(Ph2SnS)2]. This reaction reaches equilibrium in less than 5 min
in the presence of 2, whereas, without the platinum catalyst,
equilibrium was reached in ca. 2 h under comparable conditions.
In a similar way, the reaction of 2 with [(Me2SnSe)3] gives not
only 12 but also a mixture of organotin products containing
[(Me2SnSe)2(Me2SnS)] and [(Me2SnSe)(Me2SnS)2]. Many of
1
characteristic values of J(Sn2E) of 1669 Hz in 15a (PtSeSnS
linkage) and 1215 Hz in 15b (PtSSnSe linkage) (Table 1).
These metallacyclic redistribution reactions also led to
formation of mixed cyclic organotin compounds. For example,
the reaction of 2 with [(Ph2SnS)3] gives the platinum complex
9 and then 5, and the dimethyltin groups that are eliminated

Synthesis of Metallacycles by Oxidative Addition
Inorganic Chemistry, Vol. 38, No. 9, 1999 2127
Table 5. 119Sn Chemical Shiftsa and Tin-Element Coupling Constantsb in Compounds [(Ph2Sn)3XnX′3-n (X ) S, Se, Te; n ) 2, 3)c
X
n
X′
δ (Sna)
δ (Snb)
1J (Sna-X)
1J (Snb-X)
1J (Snb-X′)
2J (Sn-X-Sn)
2J (Sn-X′-Sn)
S
3
3
3
2
2
2
2
2
2
14.7
-46.5
-206
33.0
-246
-29.4
-233
20.4
195
239
253
212
261
250
255
209
239
Se
Te
S
Te
Se
Te
S
1318
3366
Te
S
Te
Se
Se
S
-102
-73.6
-133
-111
-18.9
-11.9
3513
243
216
252
250
233
220
3883
1337
3312
3609
1274
3522
3465
1291
1332
Se
-55.0
1309
1342
b
a In ppm; ref Me4Sn. 1J values are for 1J(119Sn-X), 2J values are for 2J(119Sn-X-119Sn). c Unsymmetrical compounds are labeled as follows:
Sna-X-Snb-X′-Snb-X.
Scheme 4
Figure 4. The 119Sn NMR spectrum of the mixture of ring complexes
[(Ph2Sn)3SenTe3-n] formed by equilibration of [(Ph2Sn)3Se3] and [(Ph2-
Sn)3Te3]. Note the distinct chemical shift regions for units containing
Ph2SnSe2 (A,C), Ph2SnSeTe (D,F) and Ph2SnTe2 (B, E) units. Couplings
are not marked but are listed in Table 5.
these organotin metallacycles are new, and the characterization
data from 119Sn NMR spectra are listed in Table 5, while a
typical spectrum is shown in Figure 4.
In principle, it should be possible to extend these redistribu-
tion reactions to give unsymmetrical complexes containing Pt-
[SnR2ESnR′2E′] units, with five different groups in the metal-
lacycle, but reactions designed to give such complexes have
yielded mixtures too complex to separate or even to analyze
by NMR. For example, the reaction of complex 3 with [(Ph2-
SnTe)3], or between complexes 3 and 7, which might give
concerted cis-addition of the Sn-E bond to platinum(II), and
isomers containing such metallacycles as PtSnMe2SeSnPh2Te,
this mechanism has the advantage of naturally giving the
gave only an intractable mixture of products.
observed cis stereochemistry of oxidative addition (Schemes 1
and 4). An attempt was made to prepare a six-membered ring
by reaction of 1 with the five-membered organotin compound
Discussion
(Me2Sn)(Me2Sn)S(Me2Sn)S, but this gave a complex mixture
of products in which only the five-membered ring adduct 2 could
be charactarized by the NMR spectrum. In this case, the
stoichiometry requires oxidative addition with elimination of a
single Me2Sn unit which is presumably incorporated into other
unidentified products.
The new metallacycles are labile and undergo exchange of
R2Sn and/or E groups with reagents [(R′2SnE′)3], as depicted
in Schemes 2 and 3. In most cases studied, the reactions occur
to give what is likely the thermodynamically most stable isomer.
For mixed complexes, these have the smaller Me2Sn group R
and the bulkier Ph2Sn group â to platinum; the heavier
chalcogenide is directly bonded to the softer platinum center,
while the lighter chalcogenide bridges the two harder tin centers.
Under these circumstances, no mechanistic insights can be
obtained, since it is likely that in some cases these are not the
initial products of kinetic control. Only in one case were two
isomers formed by such exchange reactions, namely in the
formation of 15a and 15b according to Scheme 3. These
The oxidative addition of Sn-X bonds, where X ) halogen,
to complex 1 have been shown to occur by the polar SN2
mechanism,9 and so it was expected that this mechanism might
also apply to the oxidative addition of Sn-E bonds established
in the present work. An unexpected feature of the new reactions
of Scheme 1 was the formation of five-membered rather than
seven-membered rings. No intermediates were detected during
these reactions, so it cannot be established if the reactions occur
directly with loss of one R2SnE group or if a seven-membered
ring is formed and then undergoes rapid loss of an R2SnE unit.
If the polar mechanism is assumed, these two possibilities are
shown in Scheme 4. In either case, R2SndE is expected to be
very short-lived if formed and would rapidly be incorporated
into an [(R2SnE)3] trimer.4,7 Indeed, the extrusion of R2SnE from
a seven-membered ring is likely to occur by a “ladder”
intermediate by direct reaction with a free (R2SnE)n ring.7 The
five-membered ring is often the optimum chelate ring size in
octahedral complexes and so is thermodynamically favored over
the seven-membered ring. The evidence does not preclude a

2128 Inorganic Chemistry, Vol. 38, No. 9, 1999
Janzen et al.
Scheme 5
Scheme 6
of reactivity of the group 14-group 16 bonds toward [PtMe2(bu2-
bpy)] was Sn-Te, Ge-Te . Sn-Se > Sn-S, while Ge-Se
and Ge-S bonds failed to react. These complexes show catalytic
properties and undergo interesting redistribution reactions.
Experimental Section
Reactions were performed under a nitrogen atmosphere using
standard Schlenk techniques. Solvents were freshly distilled, dried and
degassed prior to use. NMR spectra were recorded by using a Varian
Gemini (1H at 300.10 MHz) or Varian XL300 (195Pt at 64.38 MHz;
119Sn at 111.86 MHz) spectrometer. Chemical shifts are reported in
ppm with respect to TMS reference (1H), external aqueous K2PtCl4
reactions prove that the â-chalcogenide is exchanged selectively
at least in this case. Note that this is the chalcogenide having
the weaker Sn-E bonds, as shown both by the Sn-E distances
and, when E ) Se or Te, by the 1J(SnE) coupling constants. A
mechanism is still not defined. In particular, attempts to establish
if the reactions occur by exchange of R2SnE units together or
by independent exchange of R2Sn and E units were not
successful. One possible mechanism, involving the “ladder”
intermediates commonly proposed in organotin chemistry7 is
shown in Scheme 5. If Scheme 5 is correct, the reactions involve
reactivity at the tin rather than at the platinum center, but still
appear to be accelerated in the platinacyclic complexes com-
pared to the parent organotin trimers.
The evident ability of these heterometallacycles to undergo
skeletal rearrangement is reminiscent of the known chemistry
of metallacycloalkanes. In metallacyclopentanes, rearrangement
can occur by reversible formation of transient bis(alkene)
complexes; an analogous mechanism for these complexes would
involve reversible formation of a bis(R2SndE) intermediate but
this would be a 20-electron species and thus is improbable.
Again the mechanism is not established with certainty, but
reversible reductive elimination to give an 18-electron R4Sn2E2
complex is one possibility as shown in Scheme 6. These
rearrangements are faster in most cases than the reactions by
which the metallacycle is formed, so complete reductive
elimination of the (R2SnE)2 unit, which would then rearrange
to the more stable trimer (R2SnE)3, is unlikely in the isomer-
ization mechanism.
(
195Pt), or internal SnMe4 (119Sn). Unless otherwise specified, all quoted
couplings to tin are for the 119Sn isotope only. Fluorescence spectra
were recorded by using a Fluorolog-3 spectrofluorometer. Elemental
analyses were determined by Guelph Chemical Laboratories, Canada.
The complex [PtMe2(bu2bpy)]5 and the compounds [(Me2SnS)3],7c
[(Ph2SnS)3],7b [(Me2SnSe)3],7i [(Ph2SnSe)3],7b and [(Me2SnTe)3]7a were
synthesized using literature methods.
[(Ph2SnTe)3]. To a stirred mixture of tellurium powder (1.25 g, 9.8
mmol) and distilled water (10 mL) in a Schlenk tube (50 mL) was
slowly added NaBH4 (0.75 g, 19.8 mmol) in distilled water (10 mL) to
give a solution of Na+TeH-. This solution was cooled to 0 °C and
Ph2SnCl2 (3.37 g, 9.8 mmol) dissolved in ethanol (10 mL) was slowly
added. The solution was stirred for 1 h at room temperature, then
extracted with CH2Cl2 (2 × 40 mL). The extracts were filtered
repeatedly to remove suspended material to yield a yellow solution,
which was dried over MgSO4. The solution was evaporated to afford
a green-yellow precipitate of the product (2.9 g, 74%), which was
recrystallized from benzene/hexane. The compound is decomposed
slowly by exposure to air. Anal. Calcd for C36H30Sn3Te3: C, 35.99; H,
2.52. Found: C, 36.03; H, 2.20. NMR in CD2Cl2: δ(1H) 7.2-7.7 [m,
1
2
Ph]; δ(119Sn) -206 [s, JSn
) 3366 Hz, JSn-Sn ) 253 Hz].
125
Te
[(Me2GeTe)3]. To a stirred mixture of tellurium powder (3.68 g,
0.029 mol) and distilled water (20 mL) in a Schlenk tube (100 mL)
was slowly added NaBH4 (2.19 g, 0.058 mol) in distilled water (20
mL) under an N2 atmosphere. The aqueous solution was cooled to 0
°C and Me2GeCl2 (5 g, 0.028 mol) was added slowly. The solution
was stirred for 15 min at room temperature. The green-yellow precipitate
which formed was separated, dried, and extracted with petroleum ether
(bp 35-60 °C) in a Soxhlet apparatus. Evaporation of the solvent gave
In conclusion, the first examples of Sn-S, Sn-Se, Sn-Te,
and Ge-Te bond oxidative addition to platinum(II) are estab-
lished, each giving rise to a new type of metallacycle. The order

Synthesis of Metallacycles by Oxidative Addition
Inorganic Chemistry, Vol. 38, No. 9, 1999 2129
(Me2GeTe)3 (3.39 g, 53%), which was slowly decomposed on exposure
to air. Anal. Calcd for C6H18Ge3Te3: C, 10.43; H, 2.63. Found: C,
10.28; H, 2.33. NMR in CD2Cl2: δ(1H) 1.40 [s, MeGe].
[PtMe2(Me2SnSe)2(bu2bpy)], 4. To a stirred solution of [PtMe2(bu2-
bpy) (0.50 g, 1.01 mmol) in acetone (10 mL) was added (Me2SnSe)3
(0.69 g, 1.01 mmol). The solution was heated under reflux for 0.5 h to
afford a yellow, microcrystalline solid which was filtered off, washed
with acetone and n-pentane, and air-dried. Yield 0.75 g (78%). Anal.
Calcd for C24H42N2PtSe2Sn2‚C3H6O: C, 32.20; H, 4.80; N, 2.78.
Found: C, 32.19; H, 4.84; N, 2.72. NMR in CD2Cl2: δ(1H) 9.53 [d,
product was washed with acetone and n-pentane. Yield 0.34 g (81%).
1
3
3
NMR in CD2Cl2: δ(1H) 9.66 [d, H, JH
) 6.0 Hz, JPtH ) 18.9
5′ 6′
6′
H
Hz, H6′], 8.75 [d, 1H, JH H ) 6.4 Hz, JPtH ) 19.5 Hz, H6], 8.26 [d,
3
3
5
6
6
3′
4
3
1H, 4JH
) 1.9 Hz, H ], 8.21 [d, 1H, JH H ) 2.0 Hz, H ], 7.66 [dd,
3′ 5′
3 5
H
3
4
3
5′ 6′
5′ 3′
5 6
1H, JH
) 5.8 Hz, JH
) 1.92 Hz, H5′], 7.56 [dd, 1H, JH H
)
H
H
6.0 Hz, JH H ) 2.0 Hz, H5], 1.47 [s, 9H, bu], 1.45 [s, 9H, bu], 1.18
4
t
t
5
3
2
2
[s, 3H, JPtH ) 61.8 Hz, Pt-Me], 0.88 [s, 3H, JSnH ) 52.8 Hz, Pt-
Te-SnMea], 0.86 [s, 3JPtH ) 3.3 Hz, 3H, 2JSnH ) 50.1 Hz, Pt-SnMea],
0.67 [s, 3H, 3JPtH ) 4.5 Hz, 2JSnH ) 42.7 Hz, Pt-SnMeb], 0.50 [s, 3H,
2JPtH ) 59.4 Hz, Pt-Me], 0.42 [s, 3H, 2JSnH ) 53.8 Hz, Pt-Te-SnMeb];
1
1
3
6′
3
1H, 3JH
) 5.9 Hz, JPtH ) 18.6 Hz, H ]; 8.73 [d, 1H, JH H ) 5.8
125
1
5′ 6′
6′
5 6
δ(Sn) -168.1 [s, JSnPt )11 599 Hz, JSn
) 2046 Hz, Pt-Sn],
1
125 2
Te
H
-342.1 [s, 2JSnSn ) 192 Hz, 1JSn
) 2636 Hz, JSn
) 3706 Hz,
Hz, 3JPtH ) 16.6 Hz, H ], 8.25 [d, 1H, JH
) 1.9 Hz, H ], 8.21 [d,
6
4
125
1
6
3′ 5′
3′
Te
Te
H
2JSnPt ) 66 Hz, Pt-Te-Sn]; δ(195Pt) -2209 [1JPtSn ) 11 623 Hz].
[PtMe2(Ph2SnTe)2(bu2bpy)], 7, was synthesized in a similar way.
Yield 81%. Anal. Calcd for C44H50N2PtTe2Sn2: C, 40.82; H, 3.27; N,
2.16. Found: C, 40.93; H, 3.39; N, 1.60. NMR in CD2Cl2: δ(1H) 9.31
1H, 4JH H ) 2.0 Hz, H ], 7.67 [dd, 1H, JH
) 5.8 Hz, JH
) 1.9
3
3
4
3
5
5′ 6′
5′ 3′
H
H
Hz, H5′], 7.57 [dd, 1H, JH H ) 5.9 Hz, JH H ) 2.0 Hz, H ], 1.47 [s,
9H, tbu], 1.44 [s, 9H, tbu], 1.11 [s, 3H, 2JPtH ) 61.2 Hz, Pt-Me], 0.64
[s, 3H, 3JPtH ) 2.3 Hz, 2JSnH ) 51.2 Hz, Pt-SnMea], 0.62 [s, 3H, 2JSnH
) 45.7 Hz, Pt-Se-SnMea], 0.60 [s, 3H, 3JPtH ) 4.1 Hz, 2JSnH ) 44.5
3
4
5
5
6
5
3
3
3
3
5′ 6′
6′
5 6
[d, 1H, JH
) 6.3 Hz, JPtH ) 18.1 Hz, H6′], 8.81 [d, 1H, JH H
)
6 4 3′
3′ 5′
H
Hz, Pt-SnMeb], 0.36 [s, 3H, JPtH ) 60.0 Hz, Pt-Me], 0.10 [s, 3H,
5.7 Hz, 3JPtH ) 16.6 Hz, H ], 8.25 [d, 1H, JH
) 1.5 Hz, H ], 8.13
2
6
H
JSnH ) 55.8 Hz, Pt-Se-SnMeb]; δ(119Sn) 0.2 [s, 1JSn
) 1497 Hz,
[d, 1H, 4JH H ) 1.8 Hz, H ], 7.98-7.18 [m, 20H, C6H5], 7.69 [dd, 1H,
2
1
3
77
2
3 5
Se
2
1
4
5′
3
) 1106 Hz, JSnSn ) 249 Hz, Pt-Se-Sn], -77.1 [s, JPtSn
)
3JH
) 5.7 Hz, JH
) 1.8 Hz, H ], 6.89 [dd, 1H, JH H ) 5.7 Hz,
t t
77
JSn
1
5′ 6′
5′ 3′
5 6
Se
H
H
1
2
4
11 940 Hz, JSn
) 841 Hz, JSnSn ) 249 Hz, Pt-Sn]; δ(195Pt) )
JH H ) 1.8 Hz, H5], 1.49 [s, 9H, bu], 1.34 [s, 9H, bu], 1.42 [s, 3H,
77
1
5 3
Se
-2240 [1JPtSn ) 11 921 Hz].
2JPtH ) 61.4 Hz, Pt-Me], 0.56 [s, 3H, JPtH ) 58.8 Hz, Pt-Me]; δ-
2
1
2
(Sn) -340.3 [s, 1JSn
) 4112 Hz, JSn
) 2892 Hz, JSnSn ) 139
1
125 1
125
2
125
1
[PtMe2(Me2SnS)2(bu2bpy)], 2, was similarly prepard (yield 88%).
Anal. Calcd for C24H42N2PtS2Sn2‚C3H6O: C, 35.51; H, 5.30; N, 3.07.
Found: C, 35.57; H, 5.29; N, 3.01. NMR in CD2Cl2: δ(1H) 9.39 [d,
Te
Te
Hz, 2JSnPt ) 82 Hz, Pt-Te-Sn], -244.3 [s, 1JSn
) 2248 Hz, JSnPt
Te
) 12 746 Hz, Pt-Sn]; δ(195Pt) -2153 [1JPtSn ) 12 750 Hz].
3
6′
3
1H, 3JH
) 5.9 Hz, JPtH ) 18.0 Hz, H ], 8.72 [d, 1H, JH H ) 5.8
[PtMe2(Me2GeTe)2(bu2bpy)], 8. This complex was synthesized in
5′ 6′
6′
5 6
H
Hz, 3JPtH ) 12.7 Hz, H ], 8.24 [d, 1H, JH
) 1.8 Hz, H ], 8.21 [d,
a similar way. Yield 75%. NMR in CD2Cl2: δ(1H) 9.72 [d, 1H, 3JH
6
4
3′
6
3′ 5′
5′ 6′
H
H
1H, 4JH H ) 1.9 Hz, H ], 7.68 [dd, 1H, JH
) 5.7 Hz, JH
) 1.9
) 6.1 Hz, JPtH ) 17.0 Hz, H6′], 8.75 [d, 1H, JH H ) 6.0 Hz, JPtH
3
3
4
3
3
3
3
5
5′ 6′
5′ 3′
6′
5
6
6
H
H
Hz, H5′], 7.58 [dd, 1H, JH H ) 5.9 Hz, JH H ) 2.0 Hz, H ], 1.47 [s,
) 12.5 Hz, H6], 8.24 [d, 1H, 4JH
) 1.9 Hz, H ], 8.19 [d, 1H, JH H
3
4
5
3′
4
5
6
5
3
3′ 5′
3
5
H
t
t
2
3
3
4
) 2.0 Hz, H3], 7.62 [dd, 1H, JH
) 6.1 Hz, JH
) 1.9 Hz, H5′],
5′ 6′
5′ 3′
9H, bu], 1.45 [s, 9H, bu], 1.08 [s, 3H, JPtH ) 61.2 Hz, JSnH ) 3.3
Hz, Pt-Me], 0.56 [s, 3H, 3JPtH ) 4.0 Hz, 2JSnH ) 45.6 Hz, Pt-SnMea],
0.53 [s, 3H, 2JSnH ) 51.8 Hz, Pt-S-SnMea], 0.46 [s, 3H, 2JSnH ) 58.0
H
5
H
4
5
t
7.60 [dd, 1H, 3JH H ) 6.0 Hz, JH H ) 2.0 Hz, H ], 1.46 [s, 9H, bu],
5
6
3
t
2
1.45 [s, 9H, bu], 1.28 [s, 3H, JPtH ) 62.5 Hz, Pt-Me], 1.15 [s, 3H,
3JPtH ) 9.7 Hz, Pt-GeMea], 0.91 [s, 3H, 3JPtH ) 11.2 Hz, Pt-GeMeb],
0.77 [s, 3H, Pt-Te-GeMea], 0.55 [s, 3H, Pt-Te-GeMeb], 0.43 [s,
Hz, Pt-SnMeb], 0.26 [s, 3H, JPtH ) 59.1 Hz, Pt-Me], -0.06 [s, 3H,
2
2JSnH ) 58.0 Hz, Pt-S-SnMeb]; δ(119Sn) 138.1 [s, JSnSn ) 223 Hz,
2
1
2
2
Pt-S-Sn], -34.5 [s, JPtSn ) 12 067 Hz, JSnSn ) 223 Hz, Pt-Sn];
3H, JPtH ) 58.5 Hz, Pt-Me]; δ(195Pt) ) -2148 [s].
δ(195Pt) -1486 [1JPtSn ) 12 070 Hz].
[PtMe2{(SnMe2)Se(SnPh2)Se}(bu2bpy)], 10. To a stirred solution
of 4 (0.20 g, 0.21 mmol) in CH2Cl2 (2 mL) was added (Ph2SnSe)3
(0.22 g, 0.21 mmol). The solution was stirred for 1 h at room
temperature, and the solvent was removed in vacuo. Recrystallization
of the yellow residue from CH2Cl2/n-pentane at -30 °C gave yellow
microcrystals, which were isolated and purified as described for 4. Yield
0.18 g (81%). Anal. Calcd for C34H46N2PtSe2Sn2: C, 38.05; H, 4.32;
N, 2.61. Found: C, 37.69; H, 4.15; N, 2.52. NMR in CD2Cl2: δ(1H)
[PtMe2(Ph2SnSe)2(bu2bpy)], 5. To a stirred solution of [PtMe2(bu2-
bpy)] (0.30 g, 0.61 mmol) in acetone (10 mL) was added (Ph2SnSe)3
(0.64 g, 0.61 mmol). The solution was heated under reflux for 5 min
to afford a dark-yellow, microcrystalline solid product, which was
filtered off, washed with acetone and n-pentane, and air-dried. Yield
82%. The product cocrystallized with free (Ph2SnSe)3; analytically pure
5 was obtained by extraction from the product by heating with acetone
(10 mL) for 2 h. The dark-yellow microcrystalline solid was then
collected as described above. Yield 0.46 g (63%). Anal. Calcd for
C44H50N2PtSe2Sn2: C, 44.14; H, 4.20; N, 2.34. Found: C, 43.84; H,
3
3
9.34 [d, 1H, JH
) 5.7 Hz, JPtH ) 18.4 Hz, H6′], 8.77 [d, 1H,
4
6 3′ 5′
5′ 6′
6′
H
JH H ) 6.0 Hz, JPtH ) 19.4 Hz, H6], 8.24 [d, 1H, JH
) 1.6 Hz,
3
3
5
6
H
H3′], 8.10 [d, 1H, JH H ) 1.7 Hz, H3], 7.35-7.08 [m, 10H, C6H5],
4
3
5
3
3
4
4.06; N, 2.25. NMR in CD2Cl2: δ(1H) 9.14 [d, 1H, JH
) 6.0 Hz,
7.70 [dd, 1H, JH
) 5.7 Hz, JH
) 1.8 Hz, H5′], 7.59 [dd, 1H,
5′ 6′
5′ 6′
5′ 3′
H
H
H
3
3
3
4
t
JPtH ) 18.3 Hz, H6′], 8.77 [d, 1H, 3JH H ) 5.7 Hz, JPtH ) 14.4 Hz,
JH H ) 7.5 Hz, JH H ) 2.4 Hz, H5], 1.48 [s, 9H, bu], 1.33 [s, 9H,
6′
5
6
6
5
6
5
3
4
4
2
3
H6], 8.25 [d, 1H, JH
) 1.5 Hz, H3′], 8.10 [d, 1H, JH H ) 1.5 Hz,
tbu], 1.17 [s, 3H, JPtH ) 60.9 Hz, Pt-Me], 0.67 [s, 3H, JPtH ) 3.4
3′ 5′
3 5
H
H3], 7.94-7.14 [m, 20H, C6H5], 7.71 [dd, 1H, 3JH
) 5.7 Hz, JH
Hz, 2JSnH ) 50.7 Hz, Pt-SnMea], 0.63 [s, 3H, 3JPtH ) 3.8 Hz, 2JSnH
)
4
5′ 6′
5′ 3′
H
H
) 1.8 Hz, H5′], 6.89 [dd, 1H, JH H ) 5.9 Hz, JH H ) 2.0 Hz, H5],
46.1 Hz, Pt-SnMeb], 0.31 [s, 3H, JPtH ) 59.7 Hz, Pt-Me]; δ(Sn)
3
4
2
5
6
5
3
t
t
2
1
1
2
77
2
77
1
1.49 [s, 9H, bu], 1.32 [s, 9H, bu], 1.31 [s, 3H, JPtH ) 60.3 Hz, Pt-
-57.4 [s, JSn
) 1645 Hz, JSn
) 1193 Hz, JSnSn ) 250 Hz,
Se
Se
Me], 0.49 [s, 3H, 2JPtH ) 59.4 Hz, Pt-Me]; δ(119Sn) -60.3 [s, 1JSn
Pt-Se-Sn], -72.5 [s, 1JSn
) 794 Hz, JSnPt ) 11 973 Hz, Pt-Sn];
1
77
2
77
1
Se
Se
2
) 1640 Hz, 1JSn
) 1178 Hz, JSnSn ) 217 Hz, Pt-Se-Sn], -194.0
1
δ(195Pt) -2161 [1JPtSn ) 11 968 Hz]. Prolonged reaction times led to
77
1
Se
[s, 1JSn
) 921 Hz, JSnPt ) 13 160 Hz, Pt-Sn]; δ(195Pt) -1964 [1JPtSn
the formation of 5.
77
1
Se
) 13 210 Hz.
[PtMe2{(SnMe2)S(SnPh2)S}(bu2bpy)], 9, was prepared similarly
(yield: 84%). Anal. Calcd for C34H46N2PtS2Sn2: C, 41.70; H, 4.73; N,
2.86. Found: C, 41.94; H, 4.61; N, 2.79. NMR in CD2Cl2: δ(1H) 9.21
[PtMe2(Ph2SnS)2(bu2bpy)], 3, was prepared similarly (yield: 84%).
Anal. Calcd for C44H50N2PtS2Sn2: C, 47.89; H, 4.57; N, 2.54. Found:
C, 47.85; H, 4.53; N, 2.49. NMR in CD2Cl2: δ(1H) 8.92 [d, 1H, 3JH
[d, 1H, JH
) 5.9 Hz, JPtH ) 18.4 Hz, H6′], 8.77 [d, 1H, JH H
)
6 4 3′
3′ 5′
3
3
3
5′ 6′
5′ 6′
6′
5 6
H
H
) 5.9 Hz, JPtH ) 17.6 Hz, H6′], 8.76 [d, 1H, JH H ) 5.9 Hz, JPtH
5.8 Hz, 3JPtH ) 14.1 Hz, H ], 8.23 [d, 1H, JH
) 1.7 Hz, H ], 8.10
3
3
3
5′
5
6
6
5
6
H
3′
4
3
) 14.5 Hz, H6], 8.23 [d, 1H, 4JH
) 1.7 Hz, H ], 8.09 [d, 1H, JH H
[d, 1H, 4JH H ) 1.9 Hz, H ], 7.62-7.08 [m, 10H, C6H5], 7.72 [dd, 1H,
3′ 5′
3
3 5
H
) 1.9 Hz, H3], 8.00-7.14 [m, 20H, C6H5], 7.73 [dd, 1H, 3JH
) 5.9
3JH
) 5.9 Hz, JH
) 1.7 Hz, H ], 7.70 [dd, 1H, JH H ) 5.8 Hz,
t t
4
5′
3
5′ 6′
5′ 6′
5′ 3′
5 6
H
H
H
Hz, 4JH
) 1.8 Hz, H ], 6.86 [dd, 1H, JH H ) 6.0 Hz, JH H ) 1.8
JH H ) 1.9 Hz, H5], 1.48 [s, 9H, bu], 1.34 [s, 9H, bu], 1.14 [s, 3H,
5′
3
4
4
5′ 3′
5
6
5
3
5 3
H
t
t
2
3
3
Hz, H5], 1.48 [s, 9H, bu], 1.31 [s, 9H, bu], 1.27 [s, 3H, JPtH ) 60.0
2JPtH ) 60.7 Hz, JSnH ) 3 Hz, Pt-Me], 0.60 [s, 3H, JPtH ) 3.9 Hz,
3
2
Hz, JSnH ) 4.1 Hz, Pt-Me], 0.47 [s, 3H, JPtH ) 57.9 Hz, Pt-Me];
2JSnH ) 45.8 Hz, Pt-SnMea], 0.57 [s, 3H, 2JSnH ) 51.6 Hz, Pt-SnMeb],
2
1
2
2
δ(119Sn) 51.94 [s, JSnSn ) 188 Hz, Pt-S-Sn], -169.1 [s, JSnPt
)
0.22 [s, 3H, JPtH ) 58.7 Hz, Pt-Me]; δ(Sn) 51.71 [s, JSnSn ) 217
Hz, Pt-S-Sn], -32.67 [s, 1JSnPt ) 12 103 Hz, Pt-Sn]; δ(195Pt) -1479
[1JPtSn ) 12 100 Hz].
13 344 Hz, Pt-Sn]; δ(195Pt) -1432 [1JPtSn ) 13 340 Hz].
[PtMe2(Me2SnTe)2(bu2bpy)], 6. To a stirred solution of [PtMe2(bu2-
bpy)] (0.20 g, 0.41 mmol) in CH2Cl2 (2 mL) was added (Me2SnTe)3
(0.34 g, 0.41 mmol). The solution was stirred for 5 min, and the solvent
was then removed in vacuo. The brown-purple microcrystalline solid
[PtMe2{SnMe2)Te(SnPh2)Te}(bu2bpy)], 11, was synthesized in a
similar way. Yield 77%. Anal. Calcd for C34H46N2PtTe2Sn2: C, 34.89;
H, 3.96; N, 2.39. Found: C, 34.51; H, 3.71; N, 2.14. NMR in CD2Cl2:

2130 Inorganic Chemistry, Vol. 38, No. 9, 1999
Janzen et al.
3
3
1
2
1
δ(1H) 9.48 [d, 1H, JH
) 6.0 Hz, JPtH ) 19.4 Hz, H6′], 8.78 [d,
JSnPt ) 11 686 Hz, JSnSn ) 238 Hz, Pt-Sn], -193.2 [s, JSn
)
5′ 6′
6′
125
2
H
Te
1H, JH H ) 6.3 Hz, JPtH ) 15.0 Hz, H6], 8.25 [d, 1H, JH
) 1.8
3845 Hz, JSn
Te-Sn].
) 1053 Hz, JSnSn ) 238 Hz, JSnPt ) 60 Hz, Pt-
3
3
4
1
2
2
5
6
6
3′ 5′
77
1
H
Se
Hz, H3′], 8.11 [d, 1H, 4JH H ) 1.8 Hz, H ], 7.28-7.06 [m, 10H, C6H5],
3
3
5
3
4
7.66 [dd, 1H, JH
) 6.2 Hz, JH
) 1.8 Hz, H5′], 7.56 [dd, 1H,
5′ 6′
5′ 3′
H
H
[PtMe2(Ph2SnS)(Ph2SnSe)(bu2bpy)], 15a, was prepared similarly
from 2 (0.075 g, 0.068 mmol) and (Ph2SnSe)3 in CH2Cl2 for 4 days.
JH H ) 7.7 Hz, JH H ) 1.5 Hz, H5], 1.48 [s, 9H, bu], 1.33 [s, 9H,
3
4
t
5
6
5
3
tbu], 1.22 [s, 3H, JPtH ) 61.2 Hz, Pt-Me], 0.88 [s, 3H, JPtH ) 3.0
2
3
Yield 0.064 g (82%). NMR in CD2Cl2: δ(1H) 1.49 [s, 9H, bu], 1.34
t
Hz, 2JSnH ) 49.7 Hz, Pt-SnMea], 0.68 [s, 3H, 3JPtH ) 4.5 Hz, 2JSnH
)
t
2
2
[s, 9H, bu], 1.30 [s, 3H, JPtH ) 58.6 Hz, Pt-Me], 0.47 [s, 3H, JPtH
) 60.0 Hz, Pt-Me]; δ(Sn) -173.1 [s, JSnPt ) 13 237 Hz, JSnSn
43.3 Hz, Pt-SnMeb], 0.44 [s, 3H, JPtH ) 58.8 Hz, Pt-Me]; δ(Sn)
2
1
2
)
-334.5 [s, 1JSn
) 4101 Hz, JSn
) 2891 Hz, JSnSn ) 181 Hz,
1 1
125
1
2
125
2
125
1
1
2
77
2
Te
Te
183 Hz, Pt-Sn], -22.3 [s, JSn
Se-Sn].
[PtMe2(Ph2SnSe)(Ph2SnS)(bu2bpy)], 15b, was prepared similarly
from 5 (0.075 g, 0.063 mmol) and (Ph2SnS)3 (0.058 g, 0.063 mmol) in
CH2Cl2 for 4 days. Yield 0.058 g, (80%). NMR in CD2Cl2: δ(1H) 1.49
) 1669 Hz, JSnSn ) 183 Hz, Pt-
Se
2
JSnPt ) 96 Hz, Pt-Te-Sn], -160.5 [s, JSn
) 1942 Hz, JSnPt )
Te
11 686 Hz, Pt-Sn]; δ(195Pt) -2197 [1JPtSn ) 11 681 Hz].
[PtMe2(Me2SnS)(Me2SnSe)(bu2bpy)], 12. A mixture of 2 (0.070
g, 0.082 mmol) and (Me2SnSe)3 (0.056 g, 0.082 mmol) in CH2Cl2 was
stirred for 8 h. The solvent was removed in vacuo, and the solid residue
was washed with acetone and n-pentane to yield the product in slightly
impure form. Yield 0.063 g (85%). The product was always contami-
nated with small amounts of 2 and 4, so it could not be isolated in
analytically pure form. NMR in CD2Cl2: δ(1H) 1.47 [s, 9H, tbu], 1.44
t
t
2
[s, 9H, bu], 1.33 [s, 9H, bu], 1.31 [s, 3H, JPtH ) 58.1 Hz, Pt-Me],
0.47 [s, 3H, 2JPtH ) 60.0 Hz, Pt-Me]; δ(Sn) -188.6 [s, 1JSnPt ) 13 253
Hz, 2JSnSn ) 224 Hz, Pt-Sn], 23.6 [s, 1JSn
Hz, Pt-S-Sn].
) 1215 Hz, JSnSn ) 224
2
77
1
Se
Reaction of 2 with MeI. To a solution of 2‚acetone (0.043 mmol)
in CD2Cl2 (0.5 mL) in an NMR tube was added MeI (0.043 mmol).
There was an immediate color change from bright to pale yellow. The
NMR spectrum recorded after 5 min showed the presence of [PtIMe3(bu2-
bpy)] and [(Me2SnS)3] only.
X-ray Structure Determinations. Data were collected at room
temperature by using a Siemens P4 diffractometer (complex 3) or an
Enraf-Nonius diffractometer fitted with a CCD detector (complexes 4,
5, and 7). Details of the crystal data and experimental parameters are
given in Table 4, and selected bond parameters are listed in Tables 2
and 3. In each case, the space group was defined by systematic absences,
an empirical absorption correction was applied, and refinement was
carried out by full-matrix, least-squares calculations on F 2. Complex
4 was found to contain an acetone molecule in the lattice, while the
lattices of the other compounds contained no solvent. Full details of
the structures are available in the supporting materials.
t
2
3
[s, 9H, bu], 1.09 [s, 3H, JPtH ) 61.1 Hz, Pt-Me], 0.57 [s, 3H, JPtH
) 4.0 Hz, JSnH ) 45.8 Hz, Pt-SnMea], 0.55 [s, 3H, JPtH ) 2.5 Hz,
2
3
2JSnH ) 51.6 Hz, Pt-SnMeb], 0.51 [s, 3H, JSnH ) 51.1 Hz, Pt-Se-
2
SnMea], 0.34 [s, 3H, JPtH ) 59.5 Hz, Pt-Me], 0.061 [s, 3H, JSnH
)
2
2
57.3 Hz, Pt-Se-SnMeb]; δ(Sn) -41.3 [s, JSnPt ) 11 951 Hz, JSnSn
1
2
) 223 Hz, Pt-Sn], 51.6 [s, 1JSn
Se-Sn].
) 1501 Hz, JSnSn ) 223 Hz, Pt-
2
77
2
Se
[PtMe2(Me2SnS)(Me2SnTe)(bu2bpy)], 13, was prepared similarly
from 6 (0.075 g, 0.072 mmol) and (Me2SnS)3 (0.039 g, 0.072 mmol)
in CH2Cl2 for 8 h. Yield 0.053 g (78%). NMR in CD2Cl2: δ(1H) 1.47
t
t
2
[s, 9H, bu], 1.44 [s, 9H, bu], 1.13 [s, 3H, JPtH ) 61.5 Hz, Pt-Me],
0.68 [s, 3H, 2JSnH ) 51.9 Hz, Pt-Te-SnMea], 0.59 [s, 3H, 3JPtH ) 3.9
Hz, 2JSnH ) 46.1 Hz, Pt-SnMea], 0.55 [s, 3H, 3JPtH ) 2.5 Hz, 2JSnH
)
51.8 Hz, Pt-SnMeb], 0.47 [s, 3H, JPtH ) 59.8 Hz, Pt-Me], 0.22 [s,
3H, 2JSnH ) 53.3 Hz, Pt-Te-SnMeb]; δ(Sn) -50.5 [s, 1JSnPt ) 11 737
2
Hz, Pt-Sn1, JSnSn ) 214 Hz, JSnPt ) 52 Hz, Pt-Sn], -128.4 [s,
2
2
1
2
125
JSn
2
) 3924 Hz, JSnSn ) 214 Hz, Pt-Te-Sn].
[PtMe2(Me2SnSe)(Me2SnTe)(bu2bpy)], 14, was also prepared simi-
Te
Acknowledgment. We thank the NSERC (Canada) for
financial support.
larly from 3 (0.070 g, 0.074 mmol) and (Me2SnTe)3 (0.061 g, 0.074
mmol) in CH2Cl2 for 8 h. Yield 0.061 g (82%). NMR in CD2Cl2: δ-
(1H) 1.47 [s, 9H, bu], 1.44 [s, 9H, bu], 1.15 [s, 3H, JPtH ) 61.6 Hz,
Supporting Information Available: X-ray crystallographic files
in CIF format, for the structures of complexes 3, 4, 5, and 7 are available
free of charge via the Internet at http://pubs.acs.org.
t
t
2
Pt-Me], 0.72 [s, 3H, JSnH ) 47.8 Hz, Pt-Te-SnMea], 0.65 [s, 3H,
2
3JPtH ) 4.0 Hz, JSnH ) 45.1 Hz, Pt-SnMea], 0.61 [s, 3H, JPtH ) 2.5
2
3
Hz, JSnH ) 44.5 Hz, Pt-SnMeb], 0.48 [s, 3H, JPtH ) 59.5 Hz, Pt-
2
2
Me], 0.31 [s, 3H, JSnH ) 55.3 Hz, Pt-Te-SnMeb]; δ(Sn) -86.0 [s,
IC980862P
2