Organoantimony Derivatives of 2,4,6-Tribromophenol

Article abstract of DOI:10.1023/A:1025628217346

2,4,6-Tribromophenoxytetraphenylantimony was prepared in 93% yield by the reaction of pentaphenylantimony with bis(2,4,6-tribromophenoxy) triphenylantimony Ph₃Sb(OC₆H₂Br ₃-2,4,6)₂ in toluene at 90°C (1 h). Bis(2,4,6-tribromophenoxy)triphenylantimony, in turn, was prepared by oxidation of triphenylstibine with hydrogen peroxide in the presence of 2,4,6-tribromophenol in ether at 20°C (12 h) in 47% yield, with the second reaction product being μ-oxobis[(2,4,6-tribromophenoxy)triphenylantimony] in which the antimony atom, according to single crystal X-ray diffraction, has a trigonal bipyramidal surrounding with the bridging oxygen atom and 2,4,6-tribromophenoxy substituents in the axial positions.

Full text of DOI:10.1023/A:1025628217346

Russian Journal of General Chemistry, Vol. 73, No. 4, 2003, pp. 541 545. Translated from Zhurnal Obshchei Khimii, Vol. 73, No. 4, 2003,
pp. 573 577.
Original Russian Text Copyright
2003 by Sharutin, Pakusina, Pushilin, Subacheva, A. Gerasimenko, E. Gerasimenko.
Organoantimony Derivatives of 2,4,6-Tribromophenol
V. V. Sharutin, A. P. Pakusina, M. A. Pushilin, O. V. Subacheva,
A. V. Gerasimenko, and E. A. Gerasimenko
Blagoveshchensk State Pedagogical University, Blagoveshchensk, Russia
Received March 20, 2001
Abstract 2,4,6-Tribromophenoxytetraphenylantimony was prepared in 93% yield by the reaction of
pentaphenylantimony with bis(2,4,6-tribromophenoxy)triphenylantimony Ph3Sb(OC6H2Br3-2,4,6)2 in toluene
at 90 C (1 h). Bis(2,4,6-tribromophenoxy)triphenylantimony, in turn, was prepared by oxidation of triphenyl-
stibine with hydrogen peroxide in the presence of 2,4,6-tribromophenol in ether at 20 C (12 h) in 47% yield,
with the second reaction product being -oxobis[(2,4,6-tribromophenoxy)triphenylantimony] in which the
antimony atom, according to single crystal X-ray diffraction, has a trigonal bipyramidal surrounding with the
bridging oxygen atom and 2,4,6-tribromophenoxy substituents in the axial positions.
Aroxytetraaryl derivatives of Sb(V), Ar4SbOAr ,
are prepared in high yields from pentaarylantimony
and phenol [1 3]. No data are available on synthesis
of such Sb(V) derivatives by the substituent redistri-
bution reaction from pentaarylantimony and symmet-
rical compounds Ar3SbX2, although numerous other
antimony derivatives Ar4SbX [X = Hlg, SCN, NO3,
OC(O)R, OSO2R] are prepared by this route in fairly
high yields [4 9].
After removal of the solvent, the target product was
washed with warm toluene. The remaining crystalline
substance, which was poorly soluble in toluene, was
identified by single crystal X-ray diffraction as -oxo-
bis[(2,4,6-tribromophenoxy)triphenylantimony] III,
the hydrolysis product of bis(2,4,6-tribromophenoxy)-
triphenylantimony. Indeed, hydrolysis of bis(2,4,6-tri-
bromophenoxy)triphenylantimony in acetone yielded
-oxobis[(2,4,6-tribromophenoxy)triphenylantimony];
this derivative was also prepared in high yield by oxi-
dative addition at equimolar ratio of the reactants.
We found that pentaphenylantimony reacts with
bis(2,4,6-tribromophenoxy)triphenylantimony in tolu-
ene at 90 C (1 h) to give a single product, 2,4,6-tri-
bromophenoxytetraphenylantimony I.
2Ph3Sb(OC6H2Br3)2 + H2O
[Ph3Sb(OC6H2Br3)]2O
III
Ph5Sb + Ph3Sb(OC6H2Br3-2,4,6)2
+ 2HOC6H2Br3,
2Ph3Sb + 2HOC6H2Br3-2,4,6 + 2H2O2
2Ph4SbOC6H2Br3-2,4,6.
III + 3H2O.
I
The target product was isolated as a coarsely crys-
talline colorless compound. The IR spectrum and
melting point of this product were identical to those
of the same compound prepared from pentaphenyl-
antimony and 2,4,6-tribromophenol:
The single crystal X-ray diffraction study of III
showed (see figure) that the antimony atom has a
trigonal bipyramidal surrounding typical of five-coor-
dinate antimony; the bridging oxygen atom and 2,4,6-
tribromophenoxy groups occupy the axial positions.
Ph5Sb + HOC6H2Br3-2,4,6
By now, structural data are available for 20
compounds (Ar3SbX)2O [10 24]. In some of them,
the SbOSb moiety is approximately linear [angle
(SbOSb) 180 ], whereas in the other compounds it
is noticeably bent ( 139.0 160.0 ). Variations in the
geometry of the SbOSb moiety may be due to steric
and electronic effects of substituents at the Sb atoms
or to features of molecular packing in the crystal.
Ph4SbOC6H2Br3-2,4,6 + PhH.
The starting bis(2,4,6-tribromophenoxy)triphenyl-
antimony II was prepared by oxidative addition from
triphenylstibine, hydrogen peroxide, and 2,4,6-tribro-
mophenol (molar ratio 1 : 2 : 1) in ether (20 C, 12 h):
Ph3Sb + 2HOC6H2Br3-2,4,6 + H2O2
The Sb atom in III has a slightly distorted trigonal
bipyramidal surrounding: The equatorial CSbC angles
range from 115.4(1) to 123.8(1) , and the axial
Ph3Sb(OC6H2Br3-2,4,6)2 + 2H2O.
II
1070-3632/03/7304-0541$25.00 2003 MAIK Nauka/Interperiodica

542
SHARUTIN et al.
Br2
C43
Br1
C42
C41
C13
C44
C45
C33
C14
C32
C15
C74
C34
C35
C75
C76
C12
C31
C73
C72
C46
C11
Sb1
C65
C64
O2
C16
O1
C66
C36
C71
Br3
Sb2
C21
C26
O3
Br4
C61
C51
C22
C52
C53
C81
C62
C82
C63
C25
C23
C56
C55
C54
C86
C24
C83
C84
Br6
C85
Br5
General view of the molecule of -oxobis[(2,4,6-tribromophenoxy)triphenylantimony].
OSbObr angles are 178.1(1) and 176.5(1) (Table 1).
The Sb1O1Sb2 angle is 144.0(1) .
to 2.112(3)
and are typical of organoantimony(V)
derivatives. The Sb OAr distances [2.185(2) and
2.170(2) ] are shorter than the distances between the
Sb and oxygen atoms of the acid residue in -oxobis-
[(nitrato)triphenylantimony] [23] and -oxobis[(2,5-
dimethylbenzenesulfonato)tri-p-tolylantimony] [24],
in which these distances are 2.264(3), 2.295(3), and
The Sb Obr bond lengths in the molecule of III are
1.968(2) and 1.974(2) (Table 1) and are somewhat
larger than those in related molecules (1.930 1.965
)
[16, 20]. The Sb C(Ph) distances range from 2.091(3)
Table 1. Selected bond lengths (d, ) and bond angles ( , deg) in the molecule of III
Bond
d
Angle
Bond
d
Angle
Sb1 O1
Sb1 C11
Sb1 C31
Sb1 C21
Sb1 O2
Sb2 O1
Sb2 C51
Sb2 C71
Sb2 C61
Sb2 O3
Br1 C42
Br2 C44
1.968(2)
2.091(3)
2.094(3)
2.112(3)
2.185(2)
1.974(2)
2.108(3)
2.111(3)
2.117(3)
2.170(2)
1.896(3)
1.901(4)
O1Sb1C11
O1Sb1C31
C11Sb1C31
O1Sb1C21
C11Sb1C21
C31Sb1C21
O1Sb1O2
90.7(1)
96.2(1)
118.8(1)
93.5(1)
118.4(1)
121.7(1)
178.1(1)
88.1(1)
85.7(1)
85.9(1)
88.6(1)
92.5(1)
Br3 C46
Br4 C82
Br5 C84
Br6 C86
O2 C41
O3 C81
C11 C12
C11 C16
C12 C13
C13 C14
C14 C15
1.892(3)
1.886(3)
1.895(3)
1.880(3)
1.312(4)
1.320(3)
1.373(4)
1.378(4)
1.383(5)
1.364(5)
1.374(5)
C51Sb2C71
O1Sb2C61
C51Sb2C61
C71Sb2C61
O1Sb2O3
123.8(1)
98.0(1)
115.4(1)
120.0(1)
176.5(1)
88.9(1)
87.1(1)
85.2(1)
144.0(1)
130.0(2)
131.3(2)
C51Sb2O3
C71Sb2O3
C61Sb2O3
Sb1O1Sb2
C41O2Sb1
C81O3Sb2
C11Sb1O2
C31Sb1O2
C21Sb1O2
O1Sb2C51
O1Sb2C71
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 4 2003

ORGANOANTIMONY DERIVATIVES OF 2,4,6-TRIBROMOPHENOL
543
Table 2. Atomic coordinates and their isotropic equivalent thermal parameters in the molecule of III
2
2
Atom
x
y
z
Ueq,
Atom
x
y
z
Ueq,
Sb1
Sb2
Br1
Br2
Br3
Br4
Br5
Br6
O1
0.88703(2) 0.66049(2) 0.27515(1) 0.03799(6) C42
1.01290(2) 0.86929(2) 0.27620(2) 0.04231(6) C43
0.58357(3) 0.60843(4) 0.46810(3) 0.0794(1) C44
0.44114(3) 0.45665(4) 0.21954(4) 0.1065(2) C45
0.91251(3) 0.42312(3) 0.11591(3) 0.0660(1) C46
1.05424(3) 1.11343(3) 0.14972(3) 0.0856(1) C51
1.51637(3) 1.07418(3) 0.10053(3) 0.0736(1) C52
1.28120(3) 0.88575(3) 0.39117(3) 0.0731(1) C53
0.6241(3) 0.5390(2)
0.5358(3) 0.5246(3)
0.5617(3) 0.4781(3)
0.6739(3) 0.4468(3)
0.7603(2) 0.4642(2)
1.1531(3) 0.8233(3)
1.1251(4) 0.8393(3)
1.2147(4) 0.8048(4)
1.3275(4) 0.7547(4)
1.3553(4) 0.7391(3)
1.2657(3) 0.7732(3)
1.0507(2) 0.7854(2)
1.1330(3) 0.6819(2)
1.1636(3) 0.6272(3)
1.1091(3) 0.6752(3)
1.0241(3) 0.7777(3)
0.9960(3) 0.8336(3)
0.8545(2) 1.0058(2)
0.8280(3) 1.0936(3)
0.7253(3) 1.1826(3)
0.6476(4) 1.1832(3)
0.6738(3) 1.0965(3)
0.7770(3) 1.0059(3)
1.1802(2) 0.9974(2)
1.1868(2) 1.0555(2)
1.2870(3) 1.0769(2)
1.3806(2) 1.0444(2)
1.3772(3) 0.9908(2)
1.2795(2) 0.9661(2)
0.3524(2) 0.050(1)
0.3325(2) 0.059(1)
0.2488(3) 0.062(1)
0.1840(2) 0.057(1)
0.2064(2) 0.045(1)
0.1499(2) 0.058(1)
0.0704(3) 0.088(2)
0.0144(3) 0.127(2)
0.0186(4) 0.140(2)
0.0579(4) 0.117(2)
0.1450(3) 0.073(1)
0.3862(2) 0.044(1)
0.3688(2) 0.054(1)
0.4379(3) 0.064(1)
0.5258(2) 0.065(1)
0.5435(2) 0.063(1)
0.4738(2) 0.052(1)
0.3007(2) 0.045(1)
0.3580(2) 0.059(1)
0.3715(3) 0.076(1)
0.3300(3) 0.094(2)
0.2736(3) 0.084(1)
0.2591(2) 0.065(1)
0.2632(2) 0.041(1)
0.1865(2) 0.050(1)
0.1371(2) 0.055(1)
0.1664(2) 0.048(1)
0.2433(2) 0.051(1)
0.2900(2) 0.042(1)
0.9481(2) 0.7753(2)
0.8204(2) 0.5317(2)
1.0865(2) 0.9758(2)
0.7815(2) 0.7124(2)
0.6619(3) 0.7368(2)
0.5984(3) 0.7582(3)
0.6541(3) 0.7568(3)
0.7731(3) 0.7360(3)
0.8353(3) 0.7136(3)
1.0556(2) 0.5359(2)
1.0814(3) 0.4359(3)
1.1905(3) 0.3554(3)
1.2742(3) 0.3752(3)
1.2491(3) 0.4752(3)
1.1394(3) 0.5563(3)
0.8106(2) 0.7112(2)
0.7293(3) 0.8156(3)
0.6731(3) 0.8493(3)
0.6994(3) 0.7788(3)
0.7811(3) 0.6758(3)
0.8370(3) 0.6418(3)
0.7397(2) 0.5127(2)
0.2380(1)
0.3117(1)
0.3100(1)
0.1946(2)
0.2287(2)
0.1707(3)
0.0794(3)
0.0449(2)
0.1024(2)
0.2192(2)
0.2507(2)
0.2108(2)
0.1394(3)
0.1065(3)
0.1473(2)
0.4144(2)
0.4420(2)
0.5339(3)
0.5970(3)
0.5692(2)
0.4781(2)
0.2908(2)
0.0505(6) C54
0.0453(6) C55
0.0487(6) C56
0.0369(8) C61
O2
O3
C11
C12
C13
C14
C15
C16
C21
C22
C23
C24
C25
C26
C31
C32
C33
C34
C35
C36
C41
0.048(1)
0.062(1)
0.072(1)
0.075(1)
0.056(1)
0.043(1)
0.055(1)
0.069(1)
0.076(1)
0.075(1)
0.055(1)
0.043(1)
0.062(1)
0.078(1)
0.079(1)
0.076(1)
0.058(1)
0.041(1)
C62
C63
C64
C65
C66
C71
C72
C73
C74
C75
C76
C81
C82
C83
C84
C85
C86
2.258(5) , respectively. Thus, the higher the electro-
negativity of the terminal ligand X, the longer the
Sb X bond and the shorter the Sb Obr bonds. This
trend is characteristic for the whole class of antimony
compounds under consideration.
structure of the aryl group {Ar = Ph ( 170.3 [16]),
o-Tol ( 161.0 [20]), p-Tol ( 180.0 [20])}.
Replacement of an electronegative terminal ligand
(Hlg, NO3, OSO2Ar, etc.) by a less electronegative
group (OAr) in the compounds (Ph3SbX)2O, as we
noticed, leads to smaller SbOSb angles; however,
available experimental data are insufficient to speak
about the effect of the electron-acceptor properties of
ligands X on the SbOSb angle.
With the aim to reveal factors responsible for the
wide variation of SbOSb angles in the compounds
(Ar3SbX)2O, we have considered the following series
of compounds: (1) (Ph3SbX)2O, X = Cl [15, 19], Br
[16, 20], I [17, 18], and (2) (Ar3SbBr)2O, Ar = Ph
[16], o-Tol [20], p-Tol [20]. In the series (Ph3SbX)2O,
the SbOSb angle ranges from 139.0 to 180.0 irre-
spective of atom X {X = Cl ( 139.0 [15], 173.1
[19]), Br ( 170.3 [16]), I ( 180.0 [17, 18], 144.6
[17])}. A similar pattern is observed with the com-
pounds (Ar3SbBr)2O in which the SbOSb angle is in
the range 161.0 180.0 and is independent of the
EXPERIMENTAL
The IR spectra were recorded on a Hitachi-215
spectrometer (mull in mineral oil, NaCl plates).
Single crystal X-ray diffraction study of -oxo-
bis[(2,4,6-tribromophenoxy)triphenylantimony] III.
C48H34Br6O3Sb2. The unit cell parameters and inten-
sities of 5065 unique reflections with I > 2 (I) were
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 4 2003

544
SHARUTIN et al.
measured on a Bruker SMART-1000CCD automatic
diffractometer (graphite monochromator, MoK radia-
tion, /2 scanning). The data were collected as
groups of 906 images at angles 0 , 90 , 180 , and
270 . -Scanning was performed with a 0.2 step
and 10 s exposure per image; the crystal detector
distance was 45 mm. The X-ray absorption in the
sample was considered taking into account indices of
faces. The crystals are triclinic; at 20 C a 13.028(2), b
-Oxobis[(2,4,6-tribromophenoxy)triphenylanti-
mony] III. To a mixture of 1.00 g of triphenylstibine
and 0.94 g of 2,4,6-tribromophenol in 10 ml of ether,
we added 0.32 ml of 30% aqueous hydrogen peroxide.
The mixture was allowed to stand for 12 h, after
which the solvent was evaporated, and the residue was
washed with 10 ml of benzene and dried. Yield of III
1
1.92 g (98%), mp 238 C. IR spectrum, , cm :
1528 s, 1438 vs, 1285 vs, 1180 s, 998 s, 850 vs.
13.451(2), c 15.722(2)
;
87.161(2) , 69.888(2) ,
67.972(2) ; V 2388.3(5) 3; space group P1; Z 2;
ACKNOWLEDGMENTS
3
dcalc 1.921 g cm . The structure was solved by the
direct method and refined by the least-squares method
in the anisotropic approximation for nonhydrogen
atoms (isotropic for hydrogen atoms) to R 0.0277,
RW 0.0571. The positions of hydrogen atoms were
calculated geometrically and included in refinement
using the rider model (C H distance 0.93 ).
The authors are grateful to the Russian Foundation
for Basic Research for the financial support of the
license for access to the Cambridge Structural Data
Bank (project no. 99-07-90133).
REFERENCES
The data collection and editing and the refinement
of the unit cell parameters were performed with the
SMART and SAINT Plus programs [25]. All the cal-
culations for the structure determination and refine-
ment were performed using the SHELXTL/PC pro-
gram package [26]. The perspective view of the mole-
cule is shown in the figure, and the atomic coordinates
are listed in Table 2.
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2,4,6-Tribromophenoxytetraphenylantimony I.
a. A mixture of 1.00 g of pentaphenylantimony,
0.65 g of 2,4,6-tribromophenol, and 10 ml of toluene
was kept at 90 C for 1 h, after which it was cooled to
18 C. The precipitated crystals were filtered off and
dried. Yield of 2,4,6-tribromophenoxytetraphenylanti-
mony 1.40 g (93%), mp 253 C.
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b. A mixture of 0.50 g of pentaphenylantimony,
1.00 g of bis[(2,4,6-tribromophenoxy)triphenylanti-
mony], and 10 ml of toluene was kept at 90 C for 1 h,
after which it was cooled to 18 C. The precipitated
crystals were filtered off and dried. Yield of 2,4,6-tri-
bromophenoxytetraphenylantimony 1.42 g (95%),
mp 253 C.
Bis(2,4,6-tribromophenoxy)triphenylantimony
II. To a mixture of 1.00 g of triphenylstibine and
1.88 g of 2,4,6-tribromophenol in 10 ml of ether, we
added 0.32 ml of 30% aqueous hydrogen peroxide.
The mixture was allowed to stand for 12 h, after
which the solvent was evaporated, and the residue was
recrystallized from toluene and dried. Yield of bis-
(2,4,6-tribromophenoxy)triphenylantimony 1.35
g
1
(47%),1 mp 168 C. IR spectrum, , cm : 1265 vs,
1182 s, 995 s, 845 vs.
1
The yield of crystalline compound III (mp 238 C), insoluble
in toluene, was 0.92 g (23%).
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 4 2003

ORGANOANTIMONY DERIVATIVES OF 2,4,6-TRIBROMOPHENOL
545
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