Synthesis and structure of tri-p-tolylantimony dibromide

Article abstract of DOI:10.1023/A:1021674010337

Tri(p-tolyl)antimony dibromide is synthesized by the oxidation of tri(p-tolyl)stibine with copper bromide CuBr₂ in acetone. According to the X-ray diffraction analysis data, the antimony atom in tri(p-tolyl)antimony dibromide has the configuration of a trigonal bipyramid with axial bromine atoms. The Sb-Br and Sb-C bond lengths are 2.631(5) and 2.111(4) A, the CSbC and BrSbBr angles are 120° and 180°, and the intramolecular Br. . .C(1,2) contacts are 3.374 and 3.517 A, respectively.

Full text of DOI:10.1023/A:1021674010337

Russian Journal of Coordination Chemistry, Vol. 28, No. 12, 2002, pp. 831–833. Translated from Koordinatsionnaya Khimiya, Vol. 28, No. 12, 2002, pp. 887–889.
Original Russian Text Copyright © 2002 by Sharutin, Sharutina, Pakusina, Platonova, Gerasimenko, Sergienko.
Synthesis and Structure of Tri-p-tolylantimony Dibromide
V. V. Sharutin, O. K. Sharutina, A. P. Pakusina, T. P. Platonova,
A. V. Gerasimenko, and A. S. Sergienko
Blagoveshchensk State Pedagogical University, ul. Lenina 104, Blagoveshchensk, 675000 Russia
Institute of Chemistry, Far East Division, Russian Academy of Sciences,
pr. Stoletiya Vladivostoka 159, Vladivostok, 690022 Russia
Received July 2, 2000
Abstract—Tri(p-tolyl)antimony dibromide is synthesized by the oxidation of tri(p-tolyl)stibine with copper
bromide CuBr2 in acetone. According to the X-ray diffraction analysis data, the antimony atom in tri(p-
tolyl)antimony dibromide has the configuration of a trigonal bipyramid with axial bromine atoms. The Sb–Br
and Sb–C bond lengths are 2.631(5) and 2.111(4) Å, the CSbC and BrSbBr angles are 120° and 180°, and the
intramolecular Br…C(1,2) contacts are 3.374 and 3.517 Å, respectively.
INTRODUCTION
tions of hydrogen atoms were calculated geometrically
and included in the refinement by the “rider” model.
The structure of phenyl derivatives of pentavalent
antimony with the general formula Ph3SbX2 (X is an
electronegative substituent) was described in [1–4].
The majority of these compounds are characterized by
trigonal-bipyramidal coordination of the central atom
with the electronegative ligands in the axial positions.
In triphenylantimony dichloride, the carbon and hydro-
gen atoms of one of the phenyl groups are close to the
chlorine atoms in spite of the arising steric hindrances
[3]. Similar contact is observed in the tri(m-tolyl)anti-
mony dichloride, wherein the distance from the equato-
rial carbon atom of one of the phenyl groups to the
chlorine atom (3.188 Å) [4] is also shorter than the sum
of the van der Waals radii of the elements (3.5 Å) [5].
The data collection and processing and the refine-
ment of the unit cell parameters were performed using
the SMART and SAINT-Plus program packages [8].
All calculations for the determination and refinement of
the structure were performed using the SHELXTL/PC
program package [9].
The main crystallographic data and results of refine-
ment of the structure are presented in Table 1. The coor-
dinates of atoms and thermal parameters are presented
in Table 2. The bond lengths and angles are given in
Table 3.
EXPERIMENTAL
Synthesis. Tri(p-tolyl)antimony dibromide (I) was
synthesized using the procedure described in [6]. A sat-
urated solution of CuBr2 (1.24 g) in acetone was added
to a solution of tri-p-tolylantimony (1.00 g) in acetone
(10 ml). The colorless precipitate of CuBr2 was formed.
The solvent was removed, and the residue was recrys-
tallized from toluene. The compound was obtained in
85% yield (1.23 g), mp 233°C, which coincides with
the data in [7].
C(3)
C(2)
Br'
Sb
C(4)
C(5)
C(3)'
C(1)
C(2)'
Br
X-ray diffraction analysis of compound I was per-
formed for the naturally faceted single crystal on a
SMART-1000 CCD diffractometer (Bruker). The data
were collected in series of 606, 435, and 230 frames at
the values of φ = 0°, 90°, and 180°, respectively (ω scan
mode with an increment of 0.3° and exposure of 10 s
per frame). The X-ray absorption in the sample was
corrected for by the indices of the crystal faces.
The structure was determined by the direct method
and refined by the least-squares method in the anisotro-
pic approximation for non-hydrogen atoms. The posi-
Molecular structure of tri(p-tolyl)antimony dibromide (I).
1070-3284/02/2812-0831$27.00 © 2002 åÄIä “Nauka /Interperiodica”

832
SHARUTIN et al.
Table 1. Summary of data collection and refinement of the tri(p-tolyl)antimony dibromide structure (I)
Parameter
Value
Empirical formula
M
C21H21Br2Sb
554.95
T, K
293(2)
λ, Å
MoKα (0.71073)
System
Cubic
Space group
a, Å
P4332
12.859(1)
V, Å3
2126.4(3)
Z
4
ρ(calcd), g/cm3
µ, mm–1
F(000)
1.733
5.055
1072
Cube (0.22 × 0.22 × 0.22 mm)
2.24 – 27.97
Crystal shape
Range of θ, deg
Intervals of refractive indices
Measured reflections
–16 ≤ h ≤ 16, –16 ≤ k ≤ 16, –16 ≤ l ≤ 16
14055
Independent reflections
Reflections with I > 2σ(I)
Refinement method
861 (Rint = 0.0427)
761
Full-matrix least-squares for F2
41
Refinement variables
GOOF
1.103
R factors for F2 > 2σ(F2)
R factors for all reflections
Molar absorption coefficient
Residual electron density (min/max), e/Å3
R1 = 0.0224, wR2 = 0.0621
R1 = 0.0275, wR2 = 0.0639
0.0005(4)
–0.402/0.357
Table 2. Coordinates of atoms (×104) and equivalent isotro-
pic thermal parameters (×103) in the tri(p-tolyl)antimony di-
bromide structure (I)
RESULTS AND DISCUSSION
The structure of tri(p-tolyl)antimony dibromide was
studied to reveal the reasons for the indicated nonva-
lence interaction. According to the X-ray diffraction
analysis data, the antimony atom in compound I has
regular trigonal-bipyramidal coordination with equato-
rial tolyl groups and axial bromine atoms (see figure).
Unlike tri(m-tolyl)antimony dichloride (II), in which
the ClSbCl angle is equal to 177.2°, these atoms in mol-
ecule I Br'SbBr have a linear arrangement. The anti-
mony atom lies exactly in the equatorial plane. The
angles between the planes of the phenyl rings and the
Atom
Sb
x
y
z
Ueq, Å2
8750
3750
11250
49.6(2)
75.6(2)
51.4(8)
67.8(8)
71(1)
Br
9931.3(2) 4931.3(2) 10068.7(2)
C(1)
C(2)
C(3)
C(4)
C(5)
8750
2589(2)
2177(3)
1439(3)
1051(3)
226(3)
10089(2)
9737(3)
8956(3)
8551(3)
7726(3)
7829(2)
7833(3)
8750
61(1)
8750
84(2)
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 28 No. 12 2002

SYNTHESIS AND STRUCTURE OF TRI-p-TOLYLANTIMONY DIBROMIDE
833
Table 3. Interatomic distances and bond angles in the tri(p-
tolyl)antimony dibromide structure (I)
Despite the high symmetry of molecule I, it contains
intramolecular Br···C(1) and Br···C(2) contacts equal to
3.374 and 3.517 Å, respectively, which are shorter than
the sum of the van der Waals radii of these atoms
(3.6 Å [5]).
Bond
Sb–Br
Sb–C(1)
d, Å
Angle
ω, deg
2.6310(5)
2.111(4)
C(1)SbC(1)'
C(1)SbBr
120.0
90.0
REFERENCES
1. Polynova, T.N. and Porai-Koshits, M.A., Zh. Strukt.
Khim., 1966, vol. 7, no. 3, p. 642.
2. Begley, M.J. and Sowerby, D.B., Acta Crystallogr., Sect.
C: Cryst. Struct. Commun., 1993, vol. 49, no. 5, p. 1044.
3. Polynova, T.N. and Porai-Koshits, M.A., Zh. Strukt.
Khim., 1966, vol. 7, no. 5, p. 743.
C(1)–C(2) 1.373(4)
C(2)–C(3) 1.382(5)
C(3)–C(4) 1.382(4)
C(4)–C(5) 1.501(7)
BrSbBr'
180.0
C(2)C(1)C(2)'
C(1)C(2)C(3)
C(4)C(3)C(2)
C(3)C(4)C(3)'
C(3)C(4)C(5)
119.3(4)
120.1(3)
121.6(3)
117.2(4)
121.4(2)
4. Sharutin, V.V., Sharutina, O.K., Pavlushkina, I.I., et al.,
Zh. Obshch. Khim., 2000, vol. 70, no. 8, p. 1308.
5. Batsanov, S.S., Zh. Neorg. Khim., 1991, vol. 36, no. 11,
p. 3015.
equatorial plane are 37.0°. The Sb–Br and Sb–C bond
lengths are 2.631(5) and 2.111(4) Å, respectively. In
molecule II, the antimony atom has a distorted trigonal-
bipyramidal arrangement of the substituents: the Sb–Cl
bond lengths are 2.462(1) and 2.479(1) Å, and the Sb–
C bond lengths are 2.101(4), 2.112(4), and 2.116(4) Å
[4]. No intramolecular contacts between the carbon
atoms of the p-tolyl ligands and chlorine atoms are
observed in tri(p-tolyl)antimony dichloride, whose
crystal molecule occupy positions with D3 symmetry
and each plane of the aryl rings makes an angle of 37.9°
with the equatorial plane [10]. Thus, the introduction of
methyl substituents into the para-position of the aryl
rings improves the symmetry of the triarylantimony
dihalide molecule.
6. Sharutin, V.V., Doctoral (Chem.) Dissertation, Irkutsk:
Inst. of Chemistry, Siberian Division, Russ. Acad. Sci.,
1995.
7. Kocheshkov, K.A., Skoldinov,A.P., and Zemlyanskii, N.N.,
Metody elementoorganicheskoi khimii. Sur’ma, vismut
(Methods of Organoelement Chemistry. Antimony. Bis-
muth), Moscow: Nauka, 1976.
8. SMART and SAINT-Plus, Versions 5.0.: Data Collection
and Processing Software for the SMART System, Madi-
son, Wisconsin, USA: Bruker AXS Inc., 1998.
9. Sheldrick, G.M., SHELXTL/PC, Versions 5.10.: An Inte-
grated System for Solving, Refining and Displaying
Crystal Structures from Diffraction Data, Madison, Wis-
consin, USA: Bruker AXS Inc., 1998.
10. Sharutina, O.K., Doctoral (Chem.) Dissertation, Irkutsk:
Inst. of Chemistry, Siberian Division, Russ. Acad. Sci.,
2001.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 28 No. 12 2002