2-Methoxy-5-bromophenyl antimony compounds. Synthesis and structure

Article abstract of DOI:10.1134/S1070363211100100

Reaction of 2-methoxy-5-bromophenyllithium with antimony trichloride in diethyl ether affords tris-(2-methoxy-5-bromophenyl)antimony benzene solvate I. Its structure and chemical transformations into the new antimony aryl derivatives were studied. Pleiade

Full text of DOI:10.1134/S1070363211100100

ISSN 1070-3632, Russian Journal of General Chemistry, 2011, Vol. 81, No. 10, pp. 2102–2105. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © V.V. Sharutin, V.S. Senchurin, O.K. Sharutina, O.V. Chagarova, 2011, published in Zhurnal Obshchei Khimii, 2011, Vol. 81,
No. 10, pp. 1649–1652.
2-Methoxy-5-bromophenyl Antimony Compounds.
Synthesis and Structure
V. V. Sharutin, V. S. Senchurin, O. K. Sharutina, and O. V. Chagarova
Blagoveshchensk State Pedagogical University, ul. Lenina 104, Blagoveshchensk, 675000 Russia
e-mail: vvsharutin@rambler.ru
Received September 27, 2011
Abstract—Reaction of 2-methoxy-5-bromophenyllithium with antimony trichloride in diethyl ether affords tris-
(2-methoxy-5-bromophenyl)antimony benzene solvate I. Its structure and chemical transformations into the
new antimony aryl derivatives were studied.
DOI: 10.1134/S1070363211100100
Oxidative addition reactions involving triarylanti-
mony, acid (HX) and hydrogen peroxide at a 1:2:1
molar ratio in air are known to yield the antimony
derivatives of general formula Ar3SbX2 [1–4]. Such
reactions of triarylantimony, which aryl ligands
contain potential coordination centers, have not been
previously studied.
According to the X-ray diffraction analysis data,
the compound I molecule has a trigonal pyramid con-
figuration. Lengths of the Sb–C bonds are 2.1603(15),
2.1631(15), and 2.1569(16) Å. The CSbC bond angles
are 92.19(6)°, 94.23(6)°, and 94.52(6)°. The methoxy
oxygen atoms are coordinated to the antimony atom
(Fig. 1). The intramolecular distances Sb···O are 2.985(1),
3.051(1), and 3.052(1) Å, which correspoonds to 81–
82% of the sum (3.7 Å [5]) of the antimony and
oxygen van der Waals radii. The presence of the
intramolecular contacts causes obviously a decrease in
the CSbC bond angles of the molecule I compared to
triphenyl- and tri-para-tolyl antimony molecules
(95.52°–97.36° [6] and 97.31° [7]), where such
contacts are absent (Table 1).
In this paper, tris(2-methoxy-5-bromophenyl)anti-
mony I was synthesized starting from 2-methoxy-5-
bromophenyllithium and antimony trichloride in
diethyl ether. The oxidative addition with participation
of compound I was investigated.
Aryllithium derivative was obtained via para-
bromoanisole lithiation with phenyllithium at room
temperature in air.
In contrast, in a tris[2-(N,N-dimethylamino)methyl-
phenyl]antimony molecule, where the intramolecular
Sb···N interactions were observed, the CSbC angles
(average value 94.67° [8]) are close to similar
parameters of the molecule I .
OMe
OMe
Li
PhLi
Et2O
+
PhH
Br
Br
Due to the intermolecular Sb···Br contacts [3.742(2) Å,
while the van der Waals radii sum of the bromine and
antimony atoms is 4.1 Å], the molecules I are joined
into the polymer chains (Fig. 2).
The resulting 2-methoxy-5-bromphenyllithium
reacts with antimony trichloride. After the aryllithium
excess decomposing with water and the solvent
removal, the residue was recrystallized from
benzene. Yield of the tris(2-methoxy-5-bromophenyl)
antimony benzene solvate is 85%.
We found that tris(2-methoxy-5-bromophenyl)-
antimony I is oxidized with bromine in chloroform
solution to give tris(2-methoxy-5-bromophenyl)anti-
mony dibromide II.
OMe
OMe
Li
Sb
SbCl3
Et2O
I + Br2 → [(2-MeO)(5-Br)C6H3]3SbBr2.
3
+
3 LiCl
II
Under the action of sodium fluoride in a water–
acetone medium, tris(2-methoxy-5-bromophenyl)-
Br
Br
I
3
2102

2-METHOXY-5-BROMOPHENYL ANTIMONY COMPOUNDS
2103
Fig. 2. Structure of tris(2-methoxy-5-bromophenyl)antimony
polymer chain in a crystal.
EXPERIMENTAL
The IR spectra were recorded on an FSM-1201 IR
Fourier spectrometer from KBr pellets.
The X-ray analysis of compound I was performed
on a Bruker AXS Smart Apex diffractometer (MoKα-
irradiation, λ 0.71073 Å, graphite monochromator).
The data collection and editing, refining the unit cell
parameters and accounting for absorption were made
using the SMART and SAINT-Plus software [9]. All
calculations to determine and clarify the structure were
performed using the SHELXL/PC software [10]. The
structure was determined by a direct method and
refined by the least squares method in an anisotropic
approximation for the nonhydrogen atoms. The main
crystallographic data for the structure I are shown in
Table 2.
Fig. 1. General view of tris(2-methoxy-5-bromophenyl)-
antimony molecule (benzene molecule is not shown).
antimony dibromide II transforms into the tris(2-
methoxy-5-bromophenyl)antimony difluoride III.
II + 2 NaF → [(2-MeO)(5-Br)C6H3]3SbF2 + 2 NaCl.
III
The oxidation of compound I with hydrogen
peroxide in the presence of phenols, carboxylic or
arylsulfonic acids in diethyl ether at room temperature
was shown to result in tris (2-methoxy-5-
bromophenyl)antimony diaryl oxides, dicarboxylates
or diaryl sulfonates, respectively, which are crystalline
substances.
Compound I benzene solvate. To a solution of
9.95 g (51.6 mmol) of 5-bromo-2-methoxyphenyl-
lithium, obtained from 9.65 g of (51.6 mmol) of para-
I + 2 НХ + H2O2
→ [(2-MeO)(5-Br)C6H3]3SbХ2 + 2 H2O,
Table 1. Bond lengths and valence angles in the structure I
X
=
2,4,6-BrC6H2O (IV), 2,4,6-NO2C6H2O (V),
Bond
Sb1–C1A
Sb1–C1B
Sb1–C1C
C2A–O1
d, Å
Angle
C1ASb1C1B
C1CSb1C1A
C1CSb1C1B
C2AO1C1AM
C2BO2C1BM
C2CO3C1CM
C4AC5ABr1
C6AC5ABr1
C4BC5BBr2
C6BC5BBr2
ω, deg
Ph(O)CO (VI), 2-MeC6H4C(O)O (VII), 4-MeC6H4C(O)O
(VIII), PhCH=CHC(O)O (IX), 4-MeC6H4SO3 (X), 2,4-
MeC6H3SO3 (XI).
2.1603(15)
2.1631(15)
2.1569(16)
1.3697(19)
1.9061(15)
1.433(2)
94.23(6)
92.19(6)
The yield of the oxidative addition products is 95%.
94.52(6)
In addition, the compound VI was synthesized by
the reaction of compound I with benzoyl peroxide in
benzene in yield of 98%.
117.44(13)
117.73(14)
117.63(14)
119.57(12)
118.83(11)
119.58(13)
119.08(13)
C
5A–Br1
I + PhC(O)OOC(O)Ph
→ [(2-MeO)(5-Br)C6H3]3Sb[OC(O)Ph]2.
C
1AM–O1
C2B–O2
C5B–Br2
C5C–Br3
1.3695(19)
1.9061(16)
1.9068(18)
1.430(2)
Thus, the antimony aryl derivatives involving two
functional groups (MeO, Br) in the aromatic ring were
first obtained. The structure of the first representative
of 2-methoxy-5-bromophenyl antimony compounds,
the tris(2-methoxy-5-bromophenyl)antimony, was studied.
C
1CM–O3
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2104
SHARUTIN et al.
Table 2. Crystallographic data, experiment and refinement
parameters for the structure I
Compound II. To a solution of 0.61 g (0.8 mmol)
of tris(2-methoxy-5-bromophenyl)antimony benzene
solvate in 30 ml of chloroform was added a solution of
0.13 g (0.8 mmol) of bromine in 20 ml of chloroform
under stirring. The solvent was removed. Yield 0.61 g
(91%), colorless crystals, mp 254°C. IR spectrum, ν,
cm–1: 3083, 2930, 2836, 1574, 1469, 1435, 1374, 1284,
1268, 1253, 1179, 1150, 1089, 1045, 1016, 813, 805,
704, 670, 618, 524, 436. Found, %: C 29.56;
2.04. C21H18Br5O3Sb. Calculated, %: C 29.89; H 2.49.
Parameter
Value
М
718.89
100.0(2)
Т, K
Crystal system
Monoclinic
P21/n
Space group
a, Å
9.00170(10)
20.9598(3)
13.5361(2)
105.0430(10)
2466.39(6)
4
b, Å
Compound III. To a solution of 0.15 g (3.6 mmol)
of sodium fluoride in 200 ml of water was added with
the stirring a solution of 0.25 g (0.3 mmol) of tris(2-
methoxy-5-bromophenyl)antimony dibromide in 25 ml
of acetone. The resulting precipitate was filtered off,
washed with water, dried and recrystallized from
benzene. Yield 0.21 g (90%), mp 234°C. IR spectrum,
ν, cm–1: 3561, 3115, 2933, 2843, 1575, 1475, 1441,
1375, 1275, 1256, 1181, 1095, 1049, 1013, 817, 810,
802, 622, 538, 524, 442. Found, %: C 34.91; H
2.23. C21H18Br3F2O3Sb. Calculated, %: C 35.10; H
2.51.
c, Å
β, deg
V, Å3
Z
dcalc, g cm–3
1.936
μ, mm–1
6.002
F(000)
1380
Crystal sizes, mm
Range for data collection
Reflection indices ranges
0.21×0.20×0.20
1.84 < θ < 31.60
–13 ≤ h ≤ 12,
–29 ≤ k ≤ 30,
–14 ≤ l ≤ 19
Compound IV. To a mixture of 0.61 g (0.8 mmol)
of tris(2-methoxy-5-bromophenyl)antimony benzene
solvate and 0.53 g (1.6 mmol) of tribromophenol in
50 ml of diethyl ether was added 0.09 ml of 30%
aqueous solution of hydrogen peroxide. The mixture
was kept for 18 h at 20°C. The resulting crystals were
filtered off and dried. Yield 0.98 g (93%), mp 164°C. IR
spectrum, ν, cm–1: 3073, 3003, 2963, 2836, 2522,
1565, 1457, 1424, 1367, 1278, 1237, 1175, 1136,
1097, 1052, 1007, 904, 858, 807, 729, 690, 613,
Reflections measured
Independent reflections
Number of variables to refinement
GООF
6979
6022
364
1.009
5844
Reflections with I > 2σ(I)
R-Factors on F2 > 2σ(F2)
R1 0.0180,
wR2 0.0364
561. Found, %:
O5Sb. Calculated, %: C 29.50; 1.64.
C
29.38;
1.44. C33H22Br9·
R-Factors on all reflections
R1 0.0259,
wR2 0.0384
Compound IX was prepared similarly from a
mixture of 0.61 g (0.8 mmol) of tris(2-methoxy-5-
bromophenyl)antimony benzene solvate and 0.24 g
(1.6 mmol) of cinnamic acid. Yield 0.60 g (78%),
mp 239°C. IR spectrum, ν, cm–1: 2936, 2832, 1705,
1648, 1558, 1459, 1435, 1374, 1284, 1260, 1232,
1180, 1142, 1085, 1038, 1014, 886, 806, 629, 668,
616 , 417. Found, %: C 39.88; H 3.04. C39H32
Br3O7Sb. Calculated, %: C 40.05; H 3.28.
Residual electron density
–0.451/0.530
(min/max), e Å–3
bromoanisole and 60.0 mmol of phenyllithium in
diethyl ether, was added 3.69 g (16.2 mmol) of
antimony trichloride in 100 ml of diethyl ether. The
mixture was stirred and kept overnight. Then it was
cautiously decomposed with water (2 ml) at the cooling.
After the solvent removal, the residue was recrystal-
lized from benzene. Yield 10.42 g (85%), colorless
crystals, mp 198°C. IR spectrum, ν, cm–1: 2933, 2834,
1563, 1488, 1425, 1371, 1283, 1261, 1234, 1177,
1136, 1088, 1073, 1042, 1017, 890, 826, 805, 767,
744, 744, 615, 540, 443. Found, %: С 42.12; Н 3.07.
C27H24O3Br3Sb. Calculated, %: С 42.74; Н 3.17.
Compound X was obtained similarly from a
mixture of 0.61 g (0.8 mmol) of tris(2-methoxy-5-
bromophenyl)antimony benzene solvate and 0.28 g
(1.6 mmol) of toluenesulfonic acid. Yield 0.77 g
(95%), mp 236°C. IR spectrum, ν, cm–1: 3074, 2952,
2842, 1575, 1479, 1369, 1278, 1246, 1175, 1046,
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 81 No. 10 2011

2-METHOXY-5-BROMOPHENYL ANTIMONY COMPOUNDS
2105
2. Sharutin, V.V., Sharutina, O.K., Panova, L.P.,
Platonova, T.P., Pakusina, A.P., and Bel’skii, V.K., Zh.
Obshch. Khim., 2002, vol. 72, no. 2, p. 249.
3. Sharutin, V.V., Sharutina, O.K., Pakusina, A.P.,
Platonova, T.P., Zhidkov, V.V., Pushilin, M.A., and
Gerasimenko, A.V., Koord. Khim., 2003, vol. 29,
no. 10, p. 750.
1007, 865, 820, 703, 671, 626, 574, 438, 406. Found,
%: C 40.86; H 3.00. C35H32Br3O9S2Sb.Calculated, %:
C 41.09; H 3.13.
Compounds V (mp 121°C, 74%), VI (mp 201°C,
71%), VII (mp 203°C, 74%), VIII (mp 183°C, 91%),
XI (mp 181°C, 93%) were obtained similarly.
4. Sharutin, V.V., Sharutina, O.K., Pakusina, A.P.,
Platonova, T.P., Gerasimenko, A.V., Bukvetskii, B.V.,
Pushilin, M.A., Koord. Khim., 2004, vol. 30, no. 1,
p. 15.
5. Batsanov, S.S., Zh. Neorg. Khim., 1991, vol. 36,
no. 12, p. 3015.
6. Grigsby, E.W.J., Hart, R.D., Raston, C.L., Skelton, B.W.,
and White, A.H., Aust. J. Chem., 1997, vol. 50, p. 675.
7. Sobolev, A.N., Romm, I.P., Belskii, V.K., and
Gur’yanova, E.N., J. Organomet. Chem., 1979,
vol. 179, p. 153.
Compound VI. A mixture of 0.61 g (0.8 mmol) of
tris(2-methoxy-5-bromophenyl)antimony benzene sol-
vate, 0.19 g (0.8 mmol) of benzoyl peroxide and 20 ml
of benzene was heated for 3 h at 40°C. The reaction
mixture was cooled, the solvent was removed. Yield
0.71 g (98%) of crystals, mp 201°C. IR spectrum, ν,
cm–1: 3068, 2932, 2835, 1647, 1582, 1479, 1382, 1323,
1291, 1252, 1175, 1123, 1046, 1020, 891, 807, 716,
684, 626, 568, 445 . Found, %:
C 45.04; H
2.87. C35H28Br3O7Sb. Calculated, %: C 45.55; H 3.04.
8. Kamepalli, S., Carmalt, C.J., Culp, R.D., Cowley, A.H.,
and Jones, R.A., Inorg. Chem., 1996, vol. 35, p. 6179.
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X-Ray Absorption Correction, Bruker-Nonius, 1990–
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p. 380.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 81 No. 10 2011