Chalcogenation reactions of overcrowded doubly bonded systems between heavier group 15 elements#

Article abstract of DOI:10.1246/bcsj.80.2425

Novel heterocyclic compounds containing chalcogen (S, Se, and Te) and pnictogen (P, Sb, and Bi) atoms were obtained by chalcogenation reactions of the doubly bonded systems between heavier group 15 elements (dipnictenes) kinetically stabilized by 2,6-bis[bis(trimethylsilyl)methyl]-4- [tris(trimethylsilyl)methyl]phenyl (Bbt) groups. Whereas the sulfurization reaction of BbtP=PBbt (1) with elemental sulfur (S₈) gave the Bbt-substituted thiadiphosphirane, i.e., the three-membered ring compound of P-S-P, those of BbtSb=SbBbt (2) and BbtBi=BiBbt (3) afforded the corresponding five-membered ring compounds, i.e., the 1,2,4,3,5-trithiadistibolane and 1,2,4,3,5-trithiadibismolane, as the main products, respectively. From each selenization reaction of dipnictenes 1-3 using elemental selenium, the corresponding three-membered ring compounds (selenadipnictiranes) were obtained as stable compounds. On the other hand, the tellurization reactions of distibene 2 and dibismuthene 3 using (n-Bu)₃P=Te gave the corresponding telluradipnictiranes as in the case of their selenization reactions, though diphosphene 1 underwent no tellurization when (n-Bu)₃P=Te or elemental tellurium was used as a tellurium source.

Full text of DOI:10.1246/bcsj.80.2425

ꢀ 2007 The Chemical Society of Japan
Bull. Chem. Soc. Jpn. Vol. 80, No. 12, 2425–2435 (2007) 2425
Chalcogenation Reactions of Overcrowded Doubly Bonded
Systems between Heavier Group 15 Elements#
ꢀ
Takahiro Sasamori, Eiko Mieda, and Norihiro Tokitoh
Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011
Received July 26, 2007; E-mail: tokitoh@boc.kuicr.kyoto-u.ac.jp
Novel heterocyclic compounds containing chalcogen (S, Se, and Te) and pnictogen (P, Sb, and Bi) atoms were
obtained by chalcogenation reactions of the doubly bonded systems between heavier group 15 elements (dipnictenes)
kinetically stabilized by 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl (Bbt) groups. Whereas
the sulfurization reaction of BbtP=PBbt (1) with elemental sulfur (S8) gave the Bbt-substituted thiadiphosphirane,
i.e., the three-membered ring compound of P–S–P, those of BbtSb=SbBbt (2) and BbtBi=BiBbt (3) afforded the cor-
responding five-membered ring compounds, i.e., the 1,2,4,3,5-trithiadistibolane and 1,2,4,3,5-trithiadibismolane, as the
main products, respectively. From each selenization reaction of dipnictenes 1–3 using elemental selenium, the corre-
sponding three-membered ring compounds (selenadipnictiranes) were obtained as stable compounds. On the other hand,
the tellurization reactions of distibene 2 and dibismuthene 3 using (n-Bu)3P=Te gave the corresponding telluradipnic-
tiranes as in the case of their selenization reactions, though diphosphene 1 underwent no tellurization when (n-Bu)3P=Te
or elemental tellurium was used as a tellurium source.
The chemistry of low-coordinated compounds of heavier
main group elements has been one of the most attractive areas1
since the first isolation of distannene Dis2Sn=SnDis2 [Dis =
CH(SiMe3)2],2 disilene Mes2Si=SiMes2 (Mes = mesityl),3
it has been found that the unique oxidation reactions of
TbtSb=SbTbt and TbtBi=BiTbt proceed in the crystalline
state to give the corresponding 1,3,2,4-dioxadistibetane9 and
1,3,2,4-dioxadibismetane11 derivatives, further elucidation of
the reactivities of TbtE=ETbt (E ¼ Sb and Bi) has been ham-
pered by their extremely low solubility in common organic
solvents. We have developed another type of a bulky aromatic
substituent, 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethyl-
silyl)methyl]phenyl (denoted as Bbt) group, which is expected
to be a potentially useful steric protecting group as well as
the Tbt group. We have reported the successful application
of Bbt group to the kinetic stabilization of the diphosphene,12
distibene,11,13 and dibismuthene11 (BbtE=EBbt, E = P, Sb,
and Bi) together with the first stable stibabismuthene14 and
ꢀ
ꢀ
ꢀ
and diphosphene Mes P=PMes (Mes = 2,4,6-tri-t-butyl-
phenyl)4 by taking advantage of kinetic stabilization. Doubly
bonded systems of heavier group 14 (dimetallenes) and 15 ele-
ments (dipnictenes) are possible even in the case of the heav-
iest element, bismuth, when they are kinetically well stabi-
lized. Recently, much more attention has been paid to the elu-
cidation of their reactivity. Above all, the cycloaddition reac-
tions of such heavier ꢀ-bond systems have been found to be
convenient routes to obtain novel heterocyclic systems. For
example, the oxidation and chalcogenation reactions of disi-
lenes, digermenes, and distannenes are known to give the cor-
responding three- or four-membered ring heterocyclic com-
pounds containing oxygen or chalcogen (S, Se, or Te) atoms.5
Indeed, Mes2Si=SiMes2 can be oxidized by atmospheric oxy-
gen to give the corresponding 1,3,2,4-dioxadisiletane deriva-
tive, although most alkenes do not react with triplet oxygen
(3O2) under ambient conditions. In addition, the Mes-substitut-
ed oxadisilirane, thiadisilirane, selenadisilirane, and tellura-
disilirane derivatives have been obtained as stable compounds
by the oxidation and chalcogenation reactions of Mes2Si=
SiMes2 using N2O,6 S8,7 Se,8 and Te,8 respectively.
In contrast to the systematic studies on the oxidation and
chalcogenation reactions of dimetallenes (or metallylenes),
the reactivities of dipnictenes have been concealed except
for the case of the kinetically stabilized diphosphene and di-
arsenes due to the lack of stable examples of a distibene and
dibismuthene until our successful isolation of the first stable
distibene9 and dibismuthene,10 TbtE=ETbt (E ¼ Sb and Bi,
Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl), by taking
advantage of an efficient steric protecting group, Tbt. Although
ꢀ
phosphabismuthene,15 BbtSb=BiBbt and BbtBi=PMes .
These heavier dipnictenes have sufficient solubility in organic
solvents. We have preliminarily reported that the sulfurization
and selenization reactions of diphosphene 1 (BbtP=PBbt) with
elemental sulfur and selenium affords the corresponding thia-
and selenadiphosphirane derivatives, respectively.12 Taking
into account that the thia- and selenadiphosphirane derivatives
are obtained as final products by the sulfurization and seleniza-
ꢀ
ꢀ
tion reactions of Mes P=PMes (4) as in the case of 1,16 the
reactivity of Bbt-substituted dipnictenes should be investigated
to examine the generality as compared with those of a diphos-
phene. Thus, we investigated the chalcogenation reactions of
BbtSb=SbBbt (2) and BbtBi=BiBbt (3). We present here
the details of the studies on the chalcogenation reactions of 2
and 3 together with systematic comparison with those of 1
(Scheme 1).
Results and Discussion
Sulfurization Reactions of the Dipnictenes. The sulfuri-
zation reaction of 1 proceeded under severe conditions
Published on the web December 13, 2007; doi:10.1246/bcsj.80.2425

2426 Bull. Chem. Soc. Jpn. Vol. 80, No. 12 (2007)
Chalcogenation Reactions of Dipnictenes
S8
R
R
Bbt
Bbt
S
S
(excess)
Bbt
E
E Bbt
E = Bi
E E
E E
C6D6
r.t.
Bbt
Bbt
n
R'
1: E = P, diphosphene
2: E = Sb, distibene
3: E = Bi, dibismuthene
2: E = Sb
3: E = Bi
E = Sb
Tbt: R=R'= Dis
18: n = 2 (69%) 7: n = 2 (quant.)
19: n = 3 (17%)
10: n = 1 (14%)
Bbt: R=Dis, R'=Tsi
Dis = CH(SiMe3)2
Tsi = C(SiMe3)3
Scheme 3.
Scheme 1.
Bbt
Bbt
+
Bbt
Se
S
S
S8
Se
+
P
P
+
Bbt P
1
P P
Bbt
P
P
Bbt P
C6D6
120 °C
120 h
C6D6
120 °C
162 h
Se
Se
S
Bbt
Bbt
Bbt
5
6
1
11 (57%)
δP –55.3
12 (12%)
δP 260.6
δSe 1371.3
δP –71.3
δP 286.7
P
P
δP 529.1
1:5:6 = 6:5:4 (1H NMR)
S8
Et3N
δSe 14.6
Bbt
1JSeP = 126 Hz JSeP = 854 Hz
1
5 (88%, isolated)
1
C6D6
120 °C
40 h
δP 529.1
Scheme 4.
ring polysulfides were obtained from the sulfurization reac-
tions of 2 and 3 in contrast to the case of the sulfurization
reaction of 1, where the three-membered ring compound (thia-
diphosphirane) forms. When distibene 2 was treated with 1
molar amount (as S) of elemental sulfur (S8) in the hope of ob-
Scheme 2.
(Scheme 2), that is, heating of 1 with elemental sulfur (S8, 4
equiv as S) at 120 ꢁC in C6D6 for 162 h affords a mixture of
the starting material 1, thiadiphosphirane 5, and dithioxophos-
1
taining Bbt-substituted thiadistibirane, the H NMR spectrum
1
phorane 6 in the ratio of 6:5:4 as judged by H NMR spec-
showed that the reaction mixture contained unidentified com-
pound X as a main product together with 2, 8, and 10. Unfortu-
nately, compound X18 could not be isolated because of its ex-
treme sensitivity toward air and moisture. On the other hand,
desulfurization of 1,3,2,4-dithiadistibetane 10 using triphenyl-
phosphine at 60 ꢁC in C6D6 did not occur, whereas 1,2,4,3,5-
trithiadistibolane 8 underwent desulfurization with triphenyl-
phosphine under the same conditions leading to the quantita-
tive formation of 10.
trum.12 On the other hand, the reaction of 1 with elemental
sulfur (S8, 10 equiv as S) in the presence of Et3N (10 equiv)
at 120 ꢁC in C6D6 for 40 h results in the exclusive formation
of thiadiphosphirane 5 (88%) as in the case of sulfurization
of Mes P=PMes (4) with elemental sulfur.16a,b
ꢀ
ꢀ
In view of these results, we examined the sulfurization reac-
tions of distibene 2 and dibismuthene 3 (Scheme 3). Treatment
of the benzene solutions of 2 and 3, which were easily pre-
pared by the reductive coupling reaction of BbtEBr2 (E ¼ Sb
and Bi) with magnesium metal in almost quantitative yields,11
with an excess amount of elemental sulfur (S8) at room tem-
perature afforded the corresponding heterocycles containing
sulfur and pnictogen (Sb and Bi) atoms, respectively.17 In con-
trast to the case of diphosphene 1, the heavier dipnictenes 2
and 3 readily underwent sulfurization reactions at room tem-
perature, indicating their higher reactivity toward elemental
sulfur than that of 1. Although 1,2,4,3,5-trithiadibismolane
derivative 7 was obtained exclusively in the sulfurization of
3 using an excess amount of elemental sulfur (S8), treatment
of 2 with an excess amount of S8 under the same conditions
afforded three types of antimony-containing cyclic poly-
sulfides, i.e., 1,2,4,3,5-trithiadistibolane 8 (69%), 1,2,3,5,4,6-
tetrathiadistibinane 9 (17%), and 1,3,2,4-dithiadistibetane 10
(14%), without any other identifiable compound as judged by
1H NMR spectroscopy. Since all of the obtained cyclic poly-
sulfides gradually decomposed during the purification proce-
dures, compounds 7 (22%), 8 (27%), 9 (4%), and 10 (9%) were
isolated in relatively low yields.
Selenization Reactions of the Dipnictenes. The diphos-
phene, BbtP=PBbt (1), has been reported to react with elemen-
tal selenium to afford the corresponding selenadiphosphirane
11 together with diselenoxophosphorane 12 as well as the case
ꢀ
ꢀ
of the selenization of Mes P=PMes (4) (Scheme 4).16c
We have preliminarily reported the unique selenium-trans-
fer reaction from (Me2N)3P=Se to the distibene 2 to form
the corresponding three-membered ring compound, selenadi-
stibirane 13.11,13 On the other hand, the selenization reaction
of 2 using elemental selenium in C6D6 in a sealed tube at high
temperature proceeded very slowly to afford a mixture of di-
stibene 2 and selenadistibirane 13 in a 1:2 ratio after heating
for a long time (6 h at 80 ꢁC, 14 h at 100 ꢁC, 40 h at 120 ꢁC, and
1
30 h at 130 ꢁC, monitored by H NMR spectroscopy). It was
found that the addition of 3 molar amount of Et3N promoted
the selenization reaction of 2. Indeed, heating of the C6D6 so-
lution of 2 with elemental selenium (grey Se, 3 molar amount)
in the presence of Et3N (3 molar amount) at 60 ꢁC for 100 h
afforded selenadistibirane 13 quantitatively as judged by the
1H NMR spectra (isolated yield; 50%) (Scheme 5).
Thus, it was found that the four-, five-, or six-membered
The selenization reactions of 2 were attempted under much

T. Sasamori et al.
Bull. Chem. Soc. Jpn. Vol. 80, No. 12 (2007) 2427
(Me2N)3P=Se
Se (2.6 mol.amt.)
Bbt
Bbt
Bbt
(excess)
Et3N (3.1 mol.amt.)
Sb Sb
Se
Bi
Bi
Bi Bi
Bbt
C6D6
80 °C
10 h
–(Me2N)3P
Se
Bbt
Bbt
C6D6
r.t.
13
(quant.)
3
15 (58%)
Bbt
Sb Sb
Bbt
2
Scheme 7.
Se (10 mol.amt.)
+
2
13
toluene-d8
2:13 = 1:2 (1H NMR)
(n-Bu)3P=Te
(2 mol.amt.)
80-130 °C
Bbt
Bbt
90 h
E
E
E
E
C6H6, r.t.
2 h
Te
Bbt
Se (3 mol.amt.)
Et3N (3 mol.amt.)
Bbt
2: E = Sb
3: E = Bi
17: E = Sb (50%)
19: E = Bi (43%)
13
C6D6
60 °C
100 h
(50%, isolated)
Bbt
Te (10 mol.amt.)
Te Te
Scheme 5.
C6H6, 120 °C
48 h
Bbt
18 (42%)
Se
Se (10 mol.amt.)
Et3N (10 mol.amt.)
E = Bi
(10 mol.amt.)
Scheme 8.
Bbt
Se3 Bbt
2
13
C6D6
80 °C
12 h
toluene-d8
130 °C
2 h
derivatives were observed in the selenization reactions of 2
and 3 (Scheme 7).
14
Tellurization Reactions of the Dipnictenes. The success-
ful synthesis of selenadipnictiranes 11, 13, and 15 naturally
prompted us to examine the tellurization reactions of dipnic-
tenes 1–3 in the expectation of obtaining unique three-mem-
bered ring systems, i.e., telluradipnictiranes,19 since to our
knowledge no example of an isolated telluradipnictirane has
been reported, except for only one report on the spectroscopic
observation of a telluradiphosphirane derivative.20
53%
78%
Scheme 6.
severer conditions in the expectation of the formation of other
cyclic polyselenides, such as diselenadistibetanes and/or
triselenadistibolanes. However, an unexpected product, tri-
selenide BbtSe3Bbt (14), was obtained (53%) as a stable prod-
uct, when 2 was treated with elemental selenium (10 molar
amount) in the presence of Et3N (10 molar amount) at 80 ꢁC
for 12 h. Although the formation mechanism for triselenide
14 is unclear at present, it can be interpreted in terms of the
intermediacy of 13 in the selenization reaction of 2. It was
supported by the fact that selenadistibirane 13 underwent fur-
ther selenization using elemental selenium (10 molar amount,
in toluene-d8, in an sealed tube, at 130 ꢁC, for 2 h) to form
BbtSe3Bbt in 78% yield (Scheme 6).
The selenization reaction using elemental selenium in the
presence of Et3N was found to be applicable to the synthesis
of the corresponding selenadibismirane. Heating dibismuthene
3 with elemental selenium (2.6 molar amount) in the presence
of Et3N (3.1 molar amount) in C6D6 at 80 ꢁC for 10 h afforded
selenadibismirane 15 quantitatively, determined from the
1H NMR spectra (isolated yield; 58%). This result indicates
that dibismuthene 3 should be more reactive toward elemental
selenium than distibene 2. Thus, three-membered ring com-
pounds 13 and 15 were obtained by the selenization reactions
of 2 and 3, respectively, in contrast to the sulfurization reac-
tions of 2 and 3, where the corresponding four-, five-, and six-
membered ring compounds were obtained without the corre-
sponding thiadipnictirane derivatives. Although diselenoxo-
phosphorane 12 formed in the selenization reaction of diphos-
phene 1,12 no diselenoxostiborane and diselenoxobismorane
In contrast to the case of selenization reactions of the
dipnictenes, however, tellurization reaction of diphosphene 1
using elemental tellurium or phosphine telluride, which is
known to be a good tellurization reagent,21 does not occur even
on heating at 120–150 ꢁC in C6D6 in a sealed tube. On the
other hand, the thermal reaction of distibene 2 with elemental
tellurium (10 molar amount) in C6D6 in a sealed tube at 120 ꢁC
for 2 days afforded the corresponding telluradistibirane 17 as a
stable compound in 15% yield. The relatively low yield of 17
is most likely due to the decomposition of the resulting prod-
ucts under the severe reaction conditions, which were indis-
pensable due to the extremely low solubility of elemental
tellurium. The tellurization reaction of dibismuthene 3 under
the same conditions gave ditelluride 18, instead of telluradibis-
mirane 19. However, we found that a phosphinetelluride, such
as (n-Bu)3P=Te, could be used as a good tellurization reagent
toward distibene 2 and dibismuthene 3 under mild conditions.
That is, treatment of distibene 2 and dibismuthene 3 with
(n-Bu)3P=Te in benzene at room temperature for 2 h gave the
corresponding telluradipnictiranes 17 (50%) and 19 (43%),
respectively.22 Tellurabismirane 19 is the ‘‘heaviest’’ example
among stable three-membered heterocyclic compounds iso-
lated as stable compounds so far (Scheme 8).
Telluradistibirane 17 was found to be thermally stable in
C6D6 solution at 140 ꢁC in a sealed tube. In addition, it was

2428 Bull. Chem. Soc. Jpn. Vol. 80, No. 12 (2007)
Chalcogenation Reactions of Dipnictenes
revealed that 17 is inert not only toward phosphine reagents,
such as PPh3 (at 100 ꢁC), P(NMe2)3 (at 120 ꢁC), and P(n-Bu)3
(at 35 ꢁC), in C6D6 in a sealed tube under heating conditions,
but also toward photo-irradiation of the C6D6 solution using
100 W medium pressure Hg lamp at 60 ꢁC in a Pyrex sealed
tube. On the other hand, heating a C6D6 solution of telluradi-
bismirane 19 at 80 ꢁC for 1 h afforded a trace amount of di-
telluride 18, though 19 was stable in solution under ambient
conditions. After the solution was heated at 100 ꢁC for 1 h,
19, 3, and 18 were observed in a ratio of 1:0.2:0.1. Additional
heating of the solution at 110 ꢁC for 1 h gave an unidentified
compound Y together with dibismuthene 3 and ditelluride 18
as the final products in a ratio of Y:3:18 = 1:2:2 as determined
from the 1H NMR spectra. Unfortunately, the reaction mechan-
ism and the structure of the final product for the decomposition
process of 19 are still unclear at present due to the instability of
compound Y during the purification procedure.
P
P
P
P
S
Se
5
11
Sb
Sb
Sb
Te
Sb
Se
Structures of the Obtained Heterocycles. The molecular
structures of the new heterocyclic compounds obtained by the
chalcogenation reactions of dipnictenes 1–3 were determined
by using X-ray crystallographic analyses. As shown in Fig. 1,
all the chalcogenadipnictiranes, 5,12 11,12 13,13 15, 17,19 and
19,19 showed isomorphous structures with an isosceles trian-
gles of the E–Ch–E atoms (E ¼ P, Sb, Bi; Ch ¼ S, Se, Te).
Their E–E bond lengths in the chalcogenadipnictiranes are
within the range of the corresponding single-bond lengths and
slightly longer (by ca. 0.002 nm) than those of the correspond-
ing tetraphenyldipnictanes (for example: Ph2P–PPh2,23 0.2217
nm; Ph2Sb–SbPh2,24 0.2837 nm; Ph2Bi–BiPh2,25 0.2990 nm)
(Table 1). Their E–Ch bond lengths are similar to or slightly
shorter than those of the corresponding single-bond com-
13
17
Bi
Se
Bi
Bi
Bi
Te
15
19
ꢀ
pounds (for examples: P–S in (Mes PS)3,26 0.2113–0.2143
nm; P–Se in Se[PPh2Cr(CO)5]2,27 0.2272 nm; Sb–Se in
Fig. 1. ORTEP drawings of chalcogenadipnictiranes (50%
probability). Hydrogen atoms, solvent molecules, and the
minor part of the disordered moieties were omitted for
clarity.
28
(DisSbSe)2[W(CO)5]2 [Dis = CH(SiMe3)2], 0.2557–0.2559
nm; Sb–Te in some inorganic cluster,29 ca. 0.28 nm; Bi–Se
in (Mes2Bi)2Se,30 0.2651 nm; Bi–Te in (Dis2Bi)2Te,28 0.2872–
0.2889 nm). These structural features observed in the chalco-
genadipnictiranes can be interpreted in terms of the tendency
Table 1. Observed Structural Parameters of Chalcogenadipnictiranes 5, 11, 13, 17, 15, and 19
a)
˚
Bond lengths/A
Bond angles/degree
Ref.
Bbt
E1
E2
Ch
E1–E2
E1–Ch
Ch–E2
Ch–E1–E2 Ch–E2–E1 E1–Ch–E2
Bbt
5: E ¼ P
Ch ¼ S
2.2349(12) 2.1083(13) 2.1285(12) 58.61(4)
57.72(4)
59.71(9)
56.15(4)
63.67(4)
59.70(8)
67.60(5)
12
12
13
18
11: E ¼ P
Ch ¼ Se
2.250(3)
2.852(2)
2.8833(6)
3.0105(4)
3.0388(3)
2.250(3)
2.562(2)
2.7607(7)
2.6492(9)
2.8546(4)
2.270(3)
2.565(1)
2.7719(6)
2.6649(8)
2.8648(4)
60.59(9)
56.25(4)
13: E ¼ Sb
Ch ¼ Se
17: E ¼ Sb
Ch ¼ Te
58.781(16) 58.402(17) 62.817(16)
15: E ¼ Bi
Ch ¼ Se
55.741(19) 55.25(2)
58.068(9) 57.742(9)
69.01(2)
This
work
18
19: E ¼ Bi
Ch ¼ Te
64.190(9)
˚
a) 1 A = 0.1 nm.

T. Sasamori et al.
Bull. Chem. Soc. Jpn. Vol. 80, No. 12 (2007) 2429
(a)
(b)
Bbt
Bbt
π-bonding
"banana bond"
E
E
vacant p orbital
E
E
S
Bbt
Ch
(A)
S
Bbt
Ch
Ar
Ar
Ar
Si
(B)
Ar
three-membered ring
large contribution
π-complex
Si
P
P
Ar
Ar
π bond
E = P, Sb, Bi; Ch = S, Se, Te
π-back donation
lone pair
high p character
Mes
Mes
Mes
Mes
Si
Mes
Mes
S
Si
Si
Si
Ch
(B)
Ch
(A)
Mes
Mes
Ar
Ar
Ar
Ar
Si
Si
three-membered ring
π-complex
π∗ orbital
large contribution
22a (Ch = S)
22b (Ch = Se)
22c (Ch = Te)
Fig. 2. Depiction of bonding properties for (a) a thiadiphos-
phirane and (b) a thiadisilirane.
Fig. 3. Structures of chalcogenadipnictiranes and chalco-
genadisiliranes.
H
H
P
P
P
P
from the disilene unit to the chalcogen atom and the ꢀ-back
donating from the chalcogen atom to the disilene unit as shown
in Fig. 2.
S
H
H
20
21
In 31P, 77Se, 125Te NMR spectra for chalcogenadipnictiranes
5,12 11,12 13,13 15, and 17,19 characteristic signals correspond-
ing to the atoms in the three-membered ring systems were
observed upfield (ꢂP ¼ ꢂ71:3 for 5; ꢂP ¼ ꢂ55:3, ꢂSe ¼ 14:6
(t, 1JSeP ¼ 126 Hz) for 11, ꢂSe ¼ ꢂ182:0 for 13, ꢂSe ¼ ꢂ136:6
(brs) for 15, ꢂTe ¼ ꢂ622:3 for 17) from those of normal acy-
clic compounds probably due to the shielding effects of heavy
Scheme 9.
of heavy atoms to maintain the (ns)2(np)3 valence electron
configuration rather than to form a hybridized orbital. That
is, the two pnictogen atoms (P, Sb, and Bi) form a three-
membered ring with one chalcogen atom (S, Se, and Te) using
three valence bonds with non-hybridized p-orbital, making a
slightly longer E–E bond than the corresponding acyclic single
bond with sp3-character, and the slightly shorter E–Ch bond
observed in the chalcogenadipnictiranes than the correspond-
ing E–Ch single bonds may be due to so-called ‘‘banana-
bonds’’ (Fig. 2).31 In addition, the E–E–C(Bbt) angles (104–
116ꢁ) less than 120ꢁ also indicate the E–C(Bbt) bond with
non-hybridized p-orbital character, though the extreme steric
hindrance of the Bbt group causes the bond angle to be larger
than 90ꢁ.
ꢀ
atoms and paramagnetic term of the corresponding n–ꢁ elec-
tron transitions. Such up-fielded chemical shifts should be
characteristic of the three-membered ring skeletons.34 Unfortu-
nately, no signal was observed in the 125Te NMR spectrum of
telluradibismirane 17, probably due to the considerable peak
broadening caused by the two adjacent bismuth atoms having
nuclear spins of 9/2.
The molecular structures of cyclic sulfides 7–10 were
also determined by using X-ray crystallographic analyses as
shown in Fig. 4.17 To the best of our knowledge, polysulfides
7–9 are the first examples of 1,2,4,3,5-trithiadibismolane,
1,2,4,3,5-trithiadistibolane, and 1,2,3,5,4,6-tetrathiadistibinane
ring systems, respectively. The five-membered ring skeletons
of 1,2,4,3,5-trithiadipnictolanes 7 and 8 were found to be
isomorphous with the half-chair geometries. Their Sb–S
[0.24349(8), 0.24806(7), 0.24398(7), and 0.24833(7) nm] and
Bi–S [0.2507(3), 0.2585(2), 0.2505(3), and 0.2582(2) nm]
bond lengths are similar to those observed for the acyclic
compounds with Sb–S [0.2444 nm in Ph2SbS(8-quinolyl)35]
and Bi–S [0.2572, 0.2557 nm in S(BiDis2)228], respectively.
1,2,4,3,5-Trithiadibismolane 7 was found to possess a half-
chair geometry for the central ring skeleton as in the case of
1,2,4,3,5-trithiadistibolane 8 (Fig. 5). On the other hand, one
can see the chair-conformation for the central 1,2,3,5,4,6-
tetrathiadistibinane ring of 9 (Fig. 6). It was found that the
1,2,3,5,4,6-tetrathiadistibinane ring was disordered (78:22)
due to the flipping of the six-membered ring. In both cases
The bonding properties of the chalcogenadipnictiranes were
supported by NBO calculations. NBO calculations for parent
thiadiphosphirane 20 and parent diphosphane 21 (Scheme 9)
showed that the hybridization of P–P and P–S bonds in
20 should be ꢁPP ¼ 0:5(sp11:93)P + 0.5(sp11:93)P and ꢁPS
¼
0:6367(sp12:63)P + 0.7711(sp10:84)S, respectively, indicating
slightly higher p-characters than that for 21, where the hybrid-
ization of the P–P bond should be ꢁPP ¼ 0:5(sp8:22)P +
0.5(sp8:22)P. In contrast to the case of chalcogenadipnictiranes,
which possess a concrete three-membered ring character (A)
(Fig. 3) as described above, chalcogenadisiliranes 22, which
have been reported to be obtained from the reaction of
Mes2Si=SiMes2 with elemental chalcogens (S8, Se, and Te),7,8
has a ꢀ-complex character (B) rather than the three-membered
ring character (A).8 Thus, it should be noted that the bonding
properties of chalcogenadipnictiranes32 differ from those of
chalcogenadisiliranes,33 which should consist of ꢀ-bonding

2430 Bull. Chem. Soc. Jpn. Vol. 80, No. 12 (2007)
Chalcogenation Reactions of Dipnictenes
of the two types of chair-conformations, two Bbt groups on the
antimony atoms are in equatorial positions. 1,3,2,4-Dithiadisti-
betane 10 was found to have an almost planar squared
ring with typical Sb–S single-bond lengths [0.24557(10) and
0.24630(9) nm] and a center of symmetry in the center of
the four-membered ring, showing the structural resemblance to
cyclo-Dis2Sb2S2 [Sb–S: 0.2425(1) and 0.2428(1) nm].36
obtained heterocyclic compounds are summarized in Table 2.
The molecular structures of the obtained heterocyclic com-
pounds were revealed by spectroscopic and X-ray crystallo-
graphic analyses. Especially, to our knowledge compounds
13, 15, 17, and 19 were the first examples of chalcogenadi-
stibiranes and chalcogenadibismiranes. It should be of great
importance that the three-membered heterocycles, chalcogena-
dipnictiranes 5, 11, 13, 15, 17, and 19, could be isolated as
stable crystalline compounds, though three-membered ring
compounds of heavier elements are known to be too reactive
and difficult to isolate due to their highly strained structures.
Conclusion
In summary, several types of chalcogenacycles containing
two pnictogen atoms were obtained by the reactions of kineti-
cally stabilized heavier dipnictenes 1–3 with elemental chalco-
gens (S8, Se, and Te) or phosphine chalcogenides [(Me2N)3P=
Se or (n-Bu)3P=Te]. It was found that the doubly bonded sys-
tems between heavier group 15 elements are good precursors
for the unique heterocycles containing pnictogen atoms. The
91.90(10)°
S
0.2033(3) nm
0.2585(2) nm
0.2582(2) nm 94.92(9)°
C(Bbt)
S
Bi
91.34(10)°
Bi
0.2505(3) nm
S
S
S
S
95.29(8)°
S
S
Bi
Sb
S
0.2507(3) nm
Bi
Sb
101.22(8)°
C(Bbt)
Fig. 5. The structure of the central ring skeleton of
1,2,4,3,5-trithiadibismolane 7.
7
8
C(Bbt)
S
Sb
S
S
S
S
Sb
Sb
S
C(Bbt)
Sb
S
S
Sb
Sb
Sb
S
S
S
Sb
S
S
Sb
Sb
S
part 1 (0.78)
part 2 (0.22)
9
10
S
S
Fig. 4. ORTEP drawings of cyclic polysulfides 7–10 (50%
probability). Hydrogen atoms and solvent molecules were
omitted for clarity.
Fig. 6. Disordered structure of the central ring skeleton of
1,2,3,5,4,6-tetrathiadistibinane 9.
Table 2. Obtained Heterocycles by the Chalcogenation Reactions of Heavier Dipnictenes 1–3
Sulfurization (S8)
Selenization (Se)
Tellurization [(n-Bu)3P=Te]
Bbt
Bbt
P
P
P
P
BbtP=PBbt (1)
BbtSb=SbBbt (2)
BbtBi=BiBbt (3)
—
S
S
Se
Bbt
Bbt
Bbt
Bbt
Bbt Sb Sb Bbt
Sb Sb
Se
Sb Sb
S
n
Te
Bbt
Bbt
n = 1, 2, 3
Bbt
Bbt
S
Bbt
Bbt
Bi Bi
S S
Bi
Bi
Bi
Bi
Se
Te
Bbt
Bbt

T. Sasamori et al.
Bull. Chem. Soc. Jpn. Vol. 80, No. 12 (2007) 2431
mental sulfur (S8, 3.3 mg, 0.10 mmol, 1 molar amount as S). After
stirring at room temperature for 7 h, the solvent was evaporated
under reduced pressure. The 1H NMR spectra of the reaction
mixture showed signals corresponding to compound X as a main
product together with distibene 2, 1,3,2,4-dithiadistibetane 10, and
1,2,4,3,5-trithiadistibolane 8. The reaction mixture was subjected
to GPLC (toluene) and PTLC to afford complicated mixture con-
taining BbtH. Compound X: 1H NMR (300 MHz, rt, C6D6) ꢂ 0.32
(s, 126H), 2.96 (s, 4H), 6.94 (s, 4H).
Experimental
General Procedure. All experiments were performed under
an argon atmosphere unless otherwise noted. All solvents
were dried by standard methods and were freshly distilled prior
to use. The 1H NMR (400 or 300 MHz) and 13C NMR (100 or
75 MHz) spectra were measured in CDCl3 or C6D6 on a JEOL
AL-400 or AL-300 spectrometer using CHCl3 (7.25 ppm) or
1
C6D5H (7.15 ppm) as an internal standard for H NMR spectrom-
etry, and using CDCl3 (77.0 ppm) or C6D6 (128.0 ppm) as the
standard for 13C NMR spectrometry. The 31P (121 MHz), 77Se (75
or 57 MHz), and 125Te NMR (125 or 94 MHz) spectra were mea-
sured in benzene-d6 or toluene-d8 with a JEOL AL-400 or AL-300
spectrometer using 85% H3PO4 in H2O (0 ppm), diphenyldisele-
nide (460 ppm), diphenylditelluride (450 ppm) as external stan-
dards, respectively. High-resolution mass spectral data were ob-
tained on a JEOL JMS-700 spectrometer. Gel permeation liquid
chromatography (GPLC) was performed on an LC-918 (Japan
Analytical Industry Co., Ltd.) equipped with JAIGEL 1H and 2H
columns (eluent: chloroform or toluene). Preparative thin-layer
chromatography (PTLC) was performed with Merck Kieselgel
60 PF254. Electronic spectra were recorded on a JASCO Ubest
V-570. High- and low-resolution mass spectral data were recorded
on a JEOL JMS-700 spectrometer. All melting points were deter-
mined on a Yanaco micro melting point apparatus and are uncor-
rected. Elemental analyses were carried out at the Microanalytical
Laboratory of the Institute for Chemical Research, Kyoto Univer-
sity. Bbt2Sb2 (2),11 Bbt2Bi2 (3),11 and (n-Bu)3PTe37 were prepared
according to the reported procedures.
Reaction of 3,5-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}-1,2,4,3,5-trithiadistibolane (8)
with Triphenylphosphine. To a benzene-d6 suspension (0.7 mL)
of Bbt2Sb2S3 (8, 5.0 mg, 3.1 mmol) was added triphenylphosphine
(5.0 mg, 19 mmol). The reaction mixture was degassed and sealed
in a 5ꢃ NMR tube. After heating at 60 ꢁC for 9 h, the signals for 8
disappeared, and those for 10 and triphenylphosphine sulfide were
1
observed without any other product in the H NMR spectrum.
Reaction of 1,2-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}dibismuthene (BbtBi=BiBbt, 3)
with Elemental Sulfur (S8). To a benzene solution (2 mL) of
Bbt2Bi2 (3, 101 mg, 60.6 mmol) was added elemental sulfur (S8,
19.0 mg, 0.606 mmol, 10 molar amount as S). After stirring at
room temperature for 1 h, the solvent was evaporated under
reduced pressure. Purification of the reaction mixture by GPLC
afforded 1,2,4,3,5-trithiadibismolane 7 (23.3 mg, 22%). 7: dark
brown crystals, mp 138–141 ꢁC (dec.); 1H NMR (300 MHz, rt,
C6D6) ꢂ 0.35 (s, 126H), 2.17 (s, 4H), 7.54 (s, 4H); 13C NMR
(75 MHz, rt, C6D6) ꢂ 1.61 (q), 1.86 (q), 5.61 (q), 22.76 (s), 37.53
(d), 128.28 (d), 131.57 (s), 145.53 (s), 151.73 (s). HRMS (FAB)
Found: m=z 1761.6051 (½M þ Hꢃþ). Calcd for C60H135Bi2S3Si14
Reaction of 1,2-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}distibene (BbtSb=SbBbt, 2) with
an Excess Amount of Elemental Sulfur (S8). To a benzene
solution (2 mL) of Bbt2Sb2 (2, 60.0 mg, 0.04 mmol) was added
elemental sulfur (S8, 12.0 mg, 0.67 mmol, 10 molar amount as S).
After stirring at room temperature for 7 h, the solvent was evapo-
rated under reduced pressure. The 1H NMR spectra of the reaction
mixture showed signals corresponding to 1,3,2,4-dithiadistibetane
10 (14%), 1,2,4,3,5-trithiadistibolane 8 (69%), 1,2,3,5,4,6-tetra-
thiadistibinane 9 (17%). Purification of the reaction mixture by
GPLC and PTLC afforded 10 (5.6 mg, 9%), 8 (17.4 mg, 27%), and
9 (2.8 mg, 4%). 10: orange crystals, mp 152 ꢁC (dec.); 1H NMR
(300 MHz, rt, C6D6) ꢂ 0.35 (s, 72H), 0.37 (s, 54H), 2.77 (s, 4H),
7.02 (s, 4H). HRMS (FAB) Found: m=z 1554.4786 ([M]þ). Calcd
for C60H134S2121Sb123SbSi14 1554.4777 ([M]þ). Anal. Calcd
for C60H134S2Sb2Si14: C, 46.30; H, 8.68%. Found: C, 46.75; H,
1761.6103 (½M þ Hꢃþ). Anal. Calcd for C60H134S3Bi2Si14 C6H14:
ꢄ
C, 42.87; H, 8.07%. Found: C, 43.08; H, 8.24%.
Reaction of 1,2-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}distibene (BbtSb=SbBbt, 2) with
an Excess Amount of Elemental Selenium. To a benzene-d6
solution (0.6 mL) of Bbt2Sb2 (2, 30.0 mg, 0.02 mmol) was added
elemental selenium (gray Se, 4.7 mg, 0.06 mmol, 3 molar amount)
and Et3N (8.4 mL, 0.06 mmol, 3 molar amount). The reaction mix-
ture was degassed and sealed in a 5ꢃ NMR tube. After the suspen-
sion was heated at 60 ꢁC for 4 days, recrystallization of the reac-
tion mixture from hexane afforded selenadistibirane 13 (15.8 mg,
0.01 mmol, 50%). The product was identified according to the
chemical data shown in Ref. 11.
Reaction of 1,2-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}distibene (BbtSb=SbBbt, 2) with
an Excess Amount of Elemental Selenium. To a benzene-d6
solution (0.6 mL) of Bbt2Sb2 (2, 71.6 mg, 0.048 mmol) was added
elemental selenium (gray Se, 11 mg, 0.14 mmol, 10 molar amount)
and Et3N (20 mL, 0.14 mmol, 10 molar amount). The reaction mix-
ture was degassed and sealed in a 5ꢃ NMR tube. After the suspen-
sion was heated at 80 ꢁC for 24 h, recrystallization of the reaction
mixture from hexane afforded BbtSe3Bbt (14, 38 mg, 0.026 mmol,
1
8.70%. 8: yellow crystals, mp 186–187 ꢁC (dec.); H NMR (300
MHz, rt, C6D6) ꢂ 0.34 (s, 126H), 2.59 (s, 4H), 7.04 (s, 4H);
13C NMR (75 MHz, rt, C6D6) ꢂ 1.70 (q), 1.89 (q), 5.60 (q), 22.74
(s), 34.84 (d), 128.12 (d), 147.61 (s), 147.94 (s), 151.12 (s).
HRMS (FAB) Found: m=z 1589.4515 (½M þ Hꢃþ). Calcd for
C60H135S3123Sb2Si14 1589.4586 (½M þ Hꢃþ). Anal. Calcd for
C60H134S3Sb2Si14 C6H14: C, 47.65; H, 8.95%. Found: C, 47.66;
ꢄ
H, 9.00%. 9: yellow crystals, mp 147 ꢁC (dec.); 1H NMR (300
MHz, rt, C6D6) ꢂ 0.33 (s, 72H), 0.34 (s, 54H), 2.72 (s, 4H), 6.99
(s, 4H). HRMS (FAB) Found: m=z 1617.4316 (½M þ Hꢃþ). Calcd
for C60H135S4121Sb2Si14 1617.4292 (½M þ Hꢃþ). Anal. Calcd for
53%). 14: orange crystal, mp 244 ꢁC (dec.); H NMR (300 MHz,
1
rt, C6D6) ꢂ 0.31 (s, 72H), 0.34 (s, 54H), 3.52 (s, 4H), 7.07 (s, 4H);
13C NMR (75 MHz, rt, C6D6) ꢂ 1.69 (q), 5.60 (q), 22.74 (s), 32.64
(d), 126.85 (d), 133.78 (s), 147.24 (s), 150.87 (s). 77Se NMR (57
MHz, rt, C6D6) ꢂ 764, 455. HRMS (FAB) Found: m=z 1486.4751
([M]þ). Calcd for C60H134Se3Si14 1486.4751 ([M]þ).
Reaction of 2,3-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}selenadistibirane (13) with an
Excess Amount of Elemental Selenium. To a toluene-d8 so-
lution (0.6 mL) of Bbt2Sb2Se (13, 34.8 mg, 0.022 mmol) was add-
C60H134S4Sb2Si14 C6H14: C, 46.44; H, 8.74%. Found: C, 46.07;
ꢄ
H, 8.57%.
Reaction of 1,2-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}distibene (BbtSb=SbBbt, 2) with
1 Molar Amount of Elemental Sulfur (S8). To a benzene solu-
tion (2 mL) of Bbt2Sb2 (2, 149.0 mg, 0.10 mmol) was added ele-

2432 Bull. Chem. Soc. Jpn. Vol. 80, No. 12 (2007)
Chalcogenation Reactions of Dipnictenes
1
ed elemental selenium (gray Se, 18.5 mg, 0.23 mmol, 10 molar
amount). The reaction mixture was degassed and sealed in a 5ꢃ
NMR tube. After the suspension was heated at 130 ꢁC for 2 h,
the sealed tube was opened. After filtration through Celiteꢁ, the
filtrate was purified by GPLC (eluent: CHCl3) to give BbtSe3Bbt
(14, 25.7 mg, 0.017 mmol, 78%).
7 h, no change was observed in the H and 31P NMR spectra.
Reaction of 2,3-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}telluradistibirane (17) with (n-
Bu)3P. To a benzene-d6 suspension (0.7 mL) of Bbt2Sb2Te (17,
10.0 mg, 6.2 mmol) was added (n-Bu)3P (7.7 mL, 31 mmol). The
reaction mixture was degassed and sealed in a 5ꢃ NMR tube.
After heating of the solution at 35 ꢁC for 2 days, no change was
Reaction of 1,2-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}dibismuthene (BbtBi=BiBbt, 3)
with Elemental Selenium. To a benzene-d6 solution (0.7 mL)
of Bbt2Bi2 (3, 16 mg, 9.6 mmol) was added elemental selenium
(gray Se, 2.0 mg, 0.025 mmol, 2.6 molar amount) and Et3N (4.2
mL, 0.03 mmol, 3.1 equiv). The reaction mixture was degassed
and sealed in a 5ꢃ NMR tube. After the suspension was heated
at 80 ꢁC for 10 h, recrystallization of the reaction mixture from
hexane afforded selenadibismirane 15 (9.8 mg, 5.6 mmol, 58%).
observed in the H and 31P NMR spectra.
1
Reaction of 1,2-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}dibismuthene (BbtBi=BiBbt, 3)
with Elemental Tellurium. To a benzene-d6 solution (0.7 mL)
of Bbt2Bi2 (3, 30 mg, 0.02 mmol) was added elemental tellurium
(26 mg, 0.20 mmol, 10 equiv). The reaction mixture was degassed
and sealed in a 5ꢃ NMR tube. After heating of the solution at
80 ꢁC for 48 h, the sealed tube was opened. The reaction mixture
was separated by GPLC (eluent: toluene) to afford ditelluride 18
(Bbt2Te2, 12.6 mg, 8.4 mmol, 42%). 18: dark green crystals, mp
239–240 ꢁC (dec.); 1H NMR (300 MHz, rt, C6D6) ꢂ 0.34 (s, 72H),
0.35 (s, 54H), 3.05 (s, 4H), 7.05 (s, 4H); 13C NMR (75 MHz, rt,
C6D6) ꢂ 2.03 (q), 5.55 (q), 22.16 (s), 39.96 (d), 122.24 (d), 125.59
(s), 146.01 (s), 152.48 (s); 125Te NMR (94 MHz, rt, C6D6) ꢂ
328.71. HRMS (FAB) Found: m=z 1505.5448 (½M þ Hꢃþ). Calcd
for C60H135Si14128Te130Te 1505.5443 (½M þ Hꢃþ). Anal. Calcd
for C60H134Si14Te2: C, 47.91; H, 8.98%. Found: C, 48.20; H,
9.05%.
1
15: dark red crystals, mp 125–126 ꢁC (dec.); H NMR (400 MHz,
rt, C6D6) ꢂ 0.32 (s, 36H), 0.33 (s, 54H), 0.34 (s, 36H), 2.53 (s,
4H), 7.24 (s, 4H); 13C NMR (100 MHz, rt, C6D6) ꢂ 2.16 (q), 2.29
(q), 5.66 (q), 22.25 (s), 41.66 (d), 128.58 (d), 145.14 (s), 151.94
(s), 172.03 (brs); 77Se NMR (75 MHz, rt, C6D6) ꢂ ꢂ136:64.
HRMS (FAB) Found: m=z 1745.6084 (½M þ Hꢃþ). Calcd for
C60H135Bi2SeSi14 1745.6106 (½M þ Hꢃþ).
Reaction of 1,2-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}distibene (BbtSb=SbBbt, 2) with
Elemental Tellurium. To a benzene-d6 solution (0.6 mL) of
Bbt2Sb2 (2, 30.0 mg, 0.02 mmol) was added elemental tellurium
(26.0 mg, 0.20 mmol, 10 equiv). The reaction mixture was de-
gassed and sealed in a 5ꢃ NMR tube. After the suspension was
heated at 120 ꢁC for 2 days, the sealed tube was opened. The re-
action mixture was purified by GPLC (eluent: toluene) to afford
telluradistibirane 17 (4.7 mg, 2.9 mmol, 15%). 17: orange crystals,
Reaction of 1,2-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}dibismuthene (BbtBi=BiBbt, 3)
with (n-Bu)3P=Te. To a benzene solution (2.0 mL) of Bbt2Bi2
(3, 49.0 mg, 0.03 mmol) was added (n-Bu)3PTe 23 mg, 0.06 mmol,
2.0 equiv) at room temperature. After standing the solution for 2 h,
reprecipitation of the reaction mixture gave telluradibismirane 19
(23.3 mg, 0.013 mmol, 43%). 19: dark brown crystals, mp 156 ꢁC
(dec.); 1H NMR (400 MHz, rt, C6D6) ꢂ 0.33 (s, 36H), 0.34 (s,
54H), 0.36 (s, 36H), 2.29 (s, 4H), 7.20 (s, 4H); 13C NMR (100
MHz, rt, C6D6) ꢂ 2.31 (q), 2.41 (q), 5.65 (q), 22.10 (s), 43.15 (d),
126.54 (d), 145.08 (s), 151.68 (s), 161.38 (s). HRMS (FAB)
Found: m=z 1795.6004 (½M þ Hꢃþ). Calcd for C60H135Bi2Si14-
130Te 1795.6004 (½M þ Hꢃþ). UV–vis (hexane) ꢄmax (") = 521
1
mp 161 ꢁC (dec.); H NMR (300 MHz, rt, C6D6) ꢂ 0.33 (s, 54H),
0.36 (s, 36H), 0.37 (s, 36H), 2.87 (s, 4H), 6.96 (s, 4H); 13C NMR
(75 MHz, rt, C6D6) ꢂ 2.09 (q), 2.28 (q), 5.65 (q), 22.21 (s), 37.69
(d), 126.90 (d), 138.33 (s), 145.83 (s), 150.88 (s); 125Te NMR
(94 MHz, rt, toluene-d8) ꢂ ꢂ622:3. HRMS (FAB) Found:
m=z 1619.4440 (½M þ Hꢃþ). Calcd for C60H135121Sb2Si14130Te
1619.4472 (½M þ Hꢃþ). UV–vis (hexane) ꢄmax (") = 458 (680),
390 (3100), 346 (8500) nm. Anal. Calcd for C60H134Sb2Si14Te:
C, 44.48; H, 8.34%. Found: C, 44.23; H, 8.23%.
(2100), 450 (3200), 338 (18700) nm. Anal. Calcd for C60H134
Bi2Si14Te: C, 40.16; H, 7.53%. Found: C, 40.12; H, 7.48%.
-
Reaction of 1,2-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}distibene (BbtSb=SbBbt, 2) with
(n-Bu)3P=Te. To a benzene solution (0.6 mL) of Bbt2Sb2 (2,
70.4 mg, 0.05 mmol) was added (n-Bu)3PTe (33 mg, 0.10 mmol,
2.0 equiv) at room temperature. After standing the solution for
2 h, filteration of the precipitated orange powder and purification
of the filtrate by GPLC afforded telluradistibirane 17 (40.0 mg,
0.025 mmol, 50%).
Theoretical Calculations. All theoretical calculations were
carried out using the Gaussian 98 program38 with density function
theory at the B3LYP method. The 6-311+G(2d,p) basis sets were
used for structural optimization and NBO calculations. It was
confirmed that the optimized structures have minimum energies
by using frequency calculations.
X-ray Crystallographic Analyses of 7, 10, 14, 15, and 18.
Crystal data of 5,12 8,17 9,17 11,12 13,13 17,19 and 1919 have previ-
ously been reported. Single crystals of 7, 10, 14, 15, and 18 suit-
able for X-ray analysis were obtained by slow recrystallization
from hexane (for 7, 14, and 15), benzene (for 10), and toluene
(for 18) at room temperature (Fig. 7). The intensity data were
collected on a Rigaku/MSC Mercury CCD diffractometer with
Reaction of 2,3-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}telluradistibirane (17) with Tri-
phenylphosphine.
To a benzene-d6 suspension (0.7 mL) of
Bbt2Sb2Te (17, 13.0 mg, 8.0 mmol) was added triphenylphosphine
(10.5 mg, 40 mmol). The reaction mixture was degassed and sealed
in a 5ꢃ NMR tube. After heating of the solution at 60 ꢁC for 24 h,
at 70 ꢁC for 24 h, at 80 ꢁC for 24 h, and 100 ꢁC for 120 h, no
˚
graphite monochromated Mo Kꢅ radiation (ꢄ ¼ 0:71069 A,
ꢁ
1 A = 0.1 nm) at ꢂ170 C to 2ꢆmax ¼ 51ꢁ. The structures were
solved by direct methods (SIR9739 or SHELXS-9740,41) and
refined by full-matrix least-squares procedures on F2 for all re-
flections (SHELXL-9741). All hydrogens were placed using
˚
1
change was observed in the H and 31P NMR spectra.
Reaction of 2,3-Bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris-
(trimethylsilyl)methyl]phenyl}telluradistibirane (17) with
(Me2N)3P. To a benzene-d6 suspension (0.7 mL) of Bbt2Sb2Te
(17, 13.0 mg, 8.0 mmol) was added (Me2N)3P (5.6 mL, 40 mmol).
The reaction mixture was degassed and sealed in a 5ꢃ NMR tube.
After heating of the solution at 40 ꢁC for 24 h and at 120 ꢁC for
AFIX instructions. Crystal data for [7 (C H )] (C H148Bi2-
66
Á
6
14
ꢀ
S3Si14): Mr ¼ 1849:24, T ¼ 103ð2Þ K, triclinic, P1 (No. 2),
˚
˚
˚
a ¼ 12:9780ð3Þ A, b ¼ 18:1816ð3Þ A, c ¼ 21:9077ð6Þ A, ꢅ ¼
69:9214ð9Þꢁ,
ꢇ ¼ 73:7562ð15Þꢁ,
ꢈ ¼ 87:8865ð10Þꢁ,
V ¼

T. Sasamori et al.
Bull. Chem. Soc. Jpn. Vol. 80, No. 12 (2007) 2433
hole 0.991 and ꢂ0:923 eAꢂ3. Crystal data for 15 (C60H134Bi2-
˚
(a)
SeSi14): Mr ¼ 1745:85, T ¼ 103ð2Þ K, triclinic, P1 (No. 1), a ¼
˚
˚
˚
9:2258ð4Þ A, b ¼ 12:5904ð11Þ A, c ¼ 18:9877ð13Þ A, ꢅ ¼
ꢁ
ꢁ
ꢁ
3
˚
86:747ð4Þ , ꢇ ¼ 84:096ð3Þ , ꢈ ¼ 73:881ð3Þ , V ¼ 2106:7ð3Þ A ,
Z ¼ 1, Dcalcd ¼ 1:376 g cmꢂ3, ꢉ ¼ 4:833 mmꢂ1, ꢄ ¼ 0:71070 A,
˚
C1
2ꢆmax ¼ 51:0, 18339 measured reflections, 13681 independent
reflections [Rint ¼ 0:0270], 737 refined parameters, GOF =
1.011, R1 ¼ 0:0359 and wR2 ¼ 0:0858 [I > 2ꢁðIÞ], R1 ¼ 0:0402
and wR2 ¼ 0:0874 [for all data], largest diff. peak and hole
Se1
Se3
C2
ꢂ3
˚
2.743 and ꢂ1:490 eA (around Bi and Se atoms). Crystal data
for [18 (C H )] (C H142Te2Si14): Mr ¼ 1596:27, T ¼ 103ð2Þ K,
Á
7
ꢀ
8
67
˚
˚
triclinic, P1 (No. 2), a ¼ 12:9377ð5Þ A, b ¼ 18:2581ð4Þ A, c ¼
˚
18:9927ð6Þ A,
ꢅ ¼ 91:8263ð9Þꢁ,
ꢇ ¼ 99:1205ð12Þꢁ,
ꢈ ¼
3
89:899ð3Þꢁ, V ¼ 4427:4ð2Þ A , Z ¼ 2, Dcalcd ¼ 1:197 g cmꢂ3
,
˚
ꢉ ¼ 0:882 mmꢂ1, ꢄ ¼ 0:71070 A, 2ꢆmax ¼ 51:0, 30658 mea-
sured reflections, 16091 independent reflections [Rint ¼ 0:0289],
891 refined parameters, GOF = 1.029, R1 ¼ 0:0264 and wR2 ¼
0:0682 [I > 2ꢁðIÞ], R1 ¼ 0:0329 and wR2 ¼ 0:0707 [for all data],
(b)
˚
˚
C1
largest diff. peak and hole 0.849 and ꢂ0:591 eAꢂ3. Crystallo-
graphic data (excluding structure factors) for the structures report-
ed in this paper have been deposited with the Cambridge Crystal-
lographic Data Centre as supplementary publication Nos. CCDC
650122 (for 7), 650123 (for 10), 650124 (for 14), 650125 (for
15), and 650126 (for 18). Copies of the data can be obtained free
of charge on application to CCDC, 12, Union Road, Cambridge,
CB2 1EZ, UK (fax: +44 1223 336033; E-mail: deposit@ccdc.
cam.ac.uk) or http://www.ccdc.cam.ac.uk/conts/retrieving.html.
Te2
Te1
C2
Fig. 7. Molecular structures of (a) triselenide 7 and (b) di-
telluride 18 (thermal ellipsoid plots, 50% probability).
Solvent molecules are omitted for clarity. Selected
structural parameters: (a) C1–Se1, 0.1927(4) nm; Se1–
Se2, 0.23344(6) nm; Se2–Se3, 0.23432(5) nm; Se3–C2,
0.1938(4) nm; C1–Se1–Se2, 100.23(10)ꢁ; Se1–Se2–Se3,
105.547(19)ꢁ; Se2–Se3–C2, 99.90(9)ꢁ; C1–Se1–Se2–Se3,
112.87(10)ꢁ; Se1–Se2–Se3–C2, 111.03(12)ꢁ. (b) C1–Te1,
0.21492(19) nm; Te1–Te2, 0.274016(19) nm; Te2–C2,
0.21469(18) nm; C1–Te1–Te2, 110.22(5)ꢁ; Te1–Te2–C2,
112.50(5)ꢁ; C1–Te1–Te2–C2, 116.83(8)ꢁ.
This work was partially supported by Grants-in-Aid for Cre-
ative Scientific Research (No. 17GS0207), Science Research
on Priority Areas (No. 19027024, ‘‘Synergy of Elements’’),
Young Scientist (B) (No. 18750030), and the 21st Century
COE and the Global COE Programs, Kyoto University Alli-
ance for Chemistry from Ministry of Education, Culture,
Sports, Science and Technology, Japan. This manuscript
was written at TU Braunschweig during the tenure of a von
Humboldt Senior Research Award of one of the authors
(Tokitoh), who is grateful to von Humboldt Stiftung for their
generosity and to Professors Reinhard Schmutzler and Wolf-
Walther du Mont for their warm hospitality.
3
4651:32ð18Þ A , Z ¼ 2, Dcalcd ¼ 1:320 g cmꢂ3, ꢉ ¼ 4:059 mmꢂ1
,
˚
˚
ꢄ ¼ 0:71070 A, 2ꢆmax ¼ 51:0, 40686 measured reflections, 17155
independent reflections [Rint ¼ 0:0250], 803 refined parameters,
GOF = 1.091, R1 ¼ 0:0635 and wR2 ¼ 0:1852 [I > 2ꢁðIÞ], R1 ¼
0:0751 and wR2 ¼ 0:1926 [for all data], largest diff. peak and hole
References
# Dedicated to Professor Renji Okazaki on the occasion of
his 70th birthday.
ꢂ3
˚
6.708 and ꢂ3:421 eA (around Bi and S atoms). Crystal data for
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1
For reviews, see: a) L. Weber, Chem. Rev. 1992, 92, 1839.
Á
6
6
72
˚
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˚
˚
Dcalcd ¼ 1:219 g cmꢂ3, ꢉ ¼ 0:838 mmꢂ1, ꢄ ¼ 0:71070 A, 2ꢆmax
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˚
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˚
Á
˚
6
14
63
ꢀ
Mr ¼ 1528:90, T ¼ 103ð2Þ K, triclinic, P1 (No. 2), a ¼
2
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12:8566ð5Þ A,
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A , Z ¼ 2, Dcalcd ¼ 1:153 g cmꢂ3
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ꢉ ¼ 1:476 mmꢂ1
,
ꢄ ¼
3
˚
˚
0:71070 A, 2ꢆmax ¼ 50:0, 29344 measured reflections, 15173
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0:0914 and wR2 ¼ 0:0844 [for all data], largest diff. peak and
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2434 Bull. Chem. Soc. Jpn. Vol. 80, No. 12 (2007)
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ꢀ
16 In the sulfurization reaction of Mes P=PMes , the
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Bull. Chem. Soc. Jpn. Vol. 80, No. 12 (2007) 2435
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¨
¨