Tetraphenylantimony aroxides Ph4SbOAr (Ar = C6H4C6H7, C6H2(Br2-2,6)(tert-Bu-4), C6H3(NO2)2-2,4, C6H2(Br2-2,6)(NO2-4)): Synthesis and structure

Article abstract of DOI:10.1134/S0036023617030147

Tetraphenylantimony aroxides Ph₄SbOAr, where Ar = C₆H₄C₆H₇ (I), C₆H₂(Br₂-2,6)(tert-Bu-4) (II), C₆H₂(Br₂-2,6)(NO₂-4) (III), and C₆H₃(NO₂)2-2,4 (IV), have been synthesized by the reaction of pentaphenylantimony with 4-cyclohexadienylphenol, 2,6-dibromo-4-tert-butylphenol, 2,6-dibromo-4-nitrophenol, and 2,4-dinitrophenol. The antimony atoms in molecules of complexes I–IV have a differently distorted trigonal bipyramidal coordination to the oxygen atoms of aroxy groups in axial positions. The OSbС angles are 177.63(13)° (I), 174.29(7)° (II), 177.8(6)° (III), and 174.01(7)° (IV). The Sb–O bond length is 2.117(3) ? (I), 2.2613(15) ? (II), 2.409(11) ? (III), and 2.4296(15) ? (IV).

Full text of DOI:10.1134/S0036023617030147

ISSN 0036-0236, Russian Journal of Inorganic Chemistry, 2017, Vol. 62, No. 3, pp. 295–300. © Pleiades Publishing, Ltd., 2017.
Original Russian Text © V.V. Sharutin, O.K. Sharutina, V.S. Senchurin, 2017, published in Zhurnal Neorganicheskoi Khimii, 2017, Vol. 62, No. 3, pp. 290–295.
COORDINATION
COMPOUNDS
Tetraphenylantimony Aroxides Ph4SbOAr
(Ar = C6H4C6H7, C6H2(Br2-2,6)(tert-Bu-4), C6H3(NO2)2-2,4,
C6H2(Br2-2,6)(NO2-4)): Synthesis and Structure
V. V. Sharutin*, O. K. Sharutina, and V. S. Senchurin
South Ural State University (National Research University), pr. Lenina 76, Chelyabinsk, 454080 Russia
*e-mail: vvsharutin@rambler.ru
Received September 21, 2015
Abstract⎯Tetraphenylantimony aroxides Ph4SbOAr, where Ar = C6H4C6H7 (I), C6H2(Br2-2,6)(tert-Bu-4)
(II), C6H2(Br2-2,6)(NO2-4) (III), and C6H3(NO2)2-2,4 (IV), have been synthesized by the reaction of pen-
taphenylantimony with 4-cyclohexadienylphenol, 2,6-dibromo-4-tert-butylphenol, 2,6-dibromo-4-nitro-
phenol, and 2,4-dinitrophenol. The antimony atoms in molecules of complexes I–IV have a differently dis-
torted trigonal bipyramidal coordination to the oxygen atoms of aroxy groups in axial positions. The OSbС
angles are 177.63(13)° (I), 174.29(7)° (II), 177.8(6)° (III), and 174.01(7)° (IV). The Sb–O bond length is
2.117(3) Å (I), 2.2613(15) Å (II), 2.409(11) Å (III), and 2.4296(15) Å (IV).
DOI: 10.1134/S0036023617030147
The analysis of published data on the structure of
Tetraphenylantimony 2,6-dibromo-4-tert-butylphe-
tetraphenylantimony aroxides, whose aroxy group noxide (II) is colorless crystals with a yield of 75% and
Tdecomp = 198°C. IR spectrum (ν, cm–1): 3048, 2958,
2864, 1578, 1478, 1435, 1383, 1292, 1246, 1182, 1065,
1021, 997, 865, 830, 733, 693, 578, 521, 472, 449. For
C34H31Br2OSb, anal. calcd. (%): C, 55.39; H, 4.21.
Found (%): C, 55.25; H, 4.35.
Tetraphenylantimony 2,6-dibromo-4-nitrophenox-
ide (III) is colorless crystals with a yield of 95% and
Tdecomp = 230°C. IR spectrum (ν, cm–1): 3068, 1560,
1547, 1480, 1460, 1435, 1325, 1308, 1187, 1160, 996,
907, 899, 843, 828, 750, 729, 690, 658, 514, 455. For
C30H22Br2NO3Sb, anal. calcd. (%): C, 49.62; H, 3.03.
Found (%): C, 49.43; H, 3.12.
contains substituents with different electronic effects,
shows that their nature governs both the bond angles at
the antimony atom and the Sb–O bond length [1–6].
In continuation of studying the effect produced by
the nature of phenol on the structure of tetraphe-
nylantimony aroxides, we have synthesized and struc-
turally characterized four new aroxides Ph4SbOAr,
where Ar = C6H4C6H7 (I), C6H2(Br2-2,6)(tert-Bu-4)
(II), C6H2(Br2-2,6)(NO2-4) (III), and C6H3(NO2)2-
2,4 (IV).
EXPERIMENTAL
Tetraphenylantimony 2,4-dinitrophenoxide (IV) is
Synthesis of tetraphenylantimony 4-cyclohexadien-
ylphenoxide (I). A mixture of pentaphenylantimony
(0.250 g, 0.50 mmol) and 4-cyclohexadienylphenol
(0.085 g, 0.50 mmol) in toluene (2 mL) was heated for
1 h at 100°C in a sealed ampoule. After cooling, the
formed colorless crystals were filtered out and dried.
Complex I (0.279 g, 93%) with Tmelt = 218°C was
obtained.
IR spectrum (ν, cm–1): 3065, 3047, 3013, 2988,
2919, 2847, 2361, 1601, 1502, 1477, 1434, 1280, 1257,
1172, 1062, 997, 847, 825, 726, 692, 594, 455. For
C36H31OSb, anal. calcd. (%): C, 71.91; H, 5.16. Found
(%): C, 71.82; H, 5.20.
yellow crystals with a yield of 86% and Tmelt = 198°C.
IR spectrum (ν, cm–1): 3102, 3055, 1591, 1518, 1473,
1434, 1314, 1135, 1059, 997, 907, 835, 736, 718, 689,
635, 454. For C30H23N2O5Sb, anal. calcd. (%): C,
58.75; H, 3.75. Found (%): C, 58.64; H, 3.84. IR spectra
of complexes I–IV were recorded on a Bruker Tensor
27 IR spectrometer as KBr pellets.
Single-crystal X-ray diffraction analysis of com-
plexes I–IV was performed on a Bruker D8 QUEST
diffractometer at 296(2) K (MoKα radiation, λ =
0.71073 Å, graphite monochromator). The collection
and edition of data, the refinement of unit cell param-
eters, and the application of absorption corrections
The other tetraphenylantimony aroxides II–IV were performed by the SMART and SAINT-Plus soft-
were synthesized in a similar way. ware [7]. All calculations in the solution and refine-
295

296
SHARUTIN et al.
Table 1. Crystallographic data, parameters of X-ray diffraction experiment, and refinement details for the structures of
complexes I–IV
Parameter
Value
I
II
III
IV
Formula weight
601.36
Monoclinic
P21/c
737.16
Monoclinic
P21/n
726.06
Monoclinic
P21/c
613.25
Orthorhombic
Pbca
Symmetry system
Space group
a, Å
13.5466(5)
18.1514(5)
12.2064(5)
99.609(2)
2959.32(18)
11.4559(4)
11.8871(4)
22.5093(7)
100.6670(10)
3012.29(17)
11.6869(9)
14.8454(12)
16.0131(12)
93.006(2)
2774.4(4)
15.2941(11)
17.6270(14)
19.6112(16)
90.00
b, Å
c, Å
β, deg
V, Å3
5287.0(7)
Z
4
4
4
8
calc, g/cm3
1.350
1.625
1.738
1.541
ρ
μ, mm–1
0.958
3.594
3.907
1.087
F(000)
1224.0
1456.0
1416.0
2464.0
Crystal size, mm
2θ range of data collection, deg
Reflection index ranges
0.48 × 0.2 × 0.16
6.1–49.54
0.44 × 0.27 × 0.12
6.02–52.82
0.35 × 0.21 × 0.18
6.02–38.7
0.81 × 0.27 × 0.17
5.72–52.76
–15 ≤ h ≤ 15,
–21 ≤ k ≤ 21,
–14 ≤ l ≤ 14
–14 ≤ h ≤ 14,
–14 ≤ k ≤ 14,
–28 ≤ l ≤ 27
–10 ≤ h ≤ 10,
–13 ≤ k ≤ 13,
–14 ≤ l ≤ 13
–19 ≤ h ≤ 19,
–22 ≤ k ≤ 22,
–24 ≤ l ≤ 24
Measured reflections
Independent reflections
Reflections with I > 2σ(I)
Rint
13557
4995
4111
0.0238
343
82835
6168
5314
0.0326
346
1.047
103288
5375
4619
0.0462
334
1.315
379547
2346
2161
0.0466
343
1.107
Refinement variables
GOOF
1.061
R-factors for F2 > 2σ(F2)
R1 = 0.0373,
wR2 = 0.0912
R1 = 0.0229,
wR2 = 0.0504
R1 = 0.0590,
wR2 = 0.1508
R1 = 0.0236,
wR2 = 0.0547
R-factors for all reflections
R1 = 0.0490,
wR2 = 0.0978
R1 = 0.0311,
wR2 = 0.0539
R1 = 0.0633,
wR2 = 0.1531
R1 = 0.0315,
wR2 = 0.0604
Residual electron density
(max/min), e/Å3
0.51/–0.45
0.71/–0.62
1.49/–0.88
0.51/–0.25
ment of structures were performed by the software
SHELXL/PC [8] and OLEX2 [9]. The structures were
solved by direct methods and refined by the least-
squares technique in the anisotropic approximation
for non-hydrogen atoms. Selected crystallographic
data and refinement results for the structures of com-
plexes I–IV are given in Table 1, and selected bind
lengths and bond angles are presented in Table 2.
Complete tables of atomic coordinates, bond
lengths, and bond angles were deposited with the
Cambridge Structure Database (nos. 1415722 for I,
1043638 for II, 1043901 for III, and 1043507 for IV,
deposit@ccdc.cam.ac.uk; http://www.ccdc.cam.ac.uk).
RESULTS AND DISCUSSION
Tetraphenylantimony aroxides I–IV were synthe-
sized via dephenylation of pentaphenylantimony by a
corresponding phenol with nearly quantitative yields:
Ph5Sb + ArOH → Ph4SbOAr + PhH,
Ar = C6H4С6H7 (I), C6H2(Br2-2,6)(t-Bu-4) (II),
C6H2(Br2-2,6)(NO2-4) (III),
C6H3(NO2)2-2,4 (IV)
Complexes I–IV were crystallized immediately
during the cooling of a reaction mixture.
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TETRAPHENYLANTIMONY AROXIDES
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Table 2. Selected bond lengths (d) and bond angles (ω) in
the structures of complexes I–IV
According to X-ray diffraction data, the antimony
atom in molecules of complexes I–IV has a differently
distorted trigonal bipyramidal coordination to the
oxygen atom of an aroxyl group in axial position
(Figs. 1–4).
Bond
d, Å
Angle
ω, deg
I
The axial ОSbС angles in complexes I, II, III, and
IV are 177.63(13)°, 174.29(7)°, 177.8(6)°, and
174.01(7)°, respectively, and the sums of angles in the
equatorial CSbC plane is 358.47(16)° (I), 357.61(9)°
(II), 354.4(7)° (III), and 352.99(8)° (IV). The anti-
mony atoms in complexes I, II, III, and IV are,
respectively, 0.152, 0.188, 0.289, and 0.326 Å out of
equatorial plane С3 towards the axial carbon atom, and
this is accompanied by the deviation of the angles
between axial and equatorial bonds from the theoreti-
cal value of 90°. The ОSbСeq angles variate within
83.13(13)°–87.85(14)° Å (I), 83.38(7)°–87.81(8)° Å
(II), 80.1(5)°–83.9(5)° Å (III), and 76.67(7)°–
84.33(7)° Å (IV), and the СaxSbСeq angles are
92.40(15)°–95.33(15)° Å (I), 93.60(8)°–97.79(9)° Å
(II), 97.8(6)°–98.1(7)° Å (III), and 97.42(8)°–
99.65(8)° (IV).
Sb(1)−O(1) 2.117(3)
Sb(1)−C(11) 2.126(4)
Sb(1)−C(1) 2.125(4)
Sb(1)−C(21) 2.116(4)
Sb(1)−C(31) 2.195(4)
O(1)−C(41) 1.337(5)
O(1)Sb(1)C(31) 177.63(13)
C(1)Sb(1)C(11) 116.70(16)
C(21)Sb(1)C(11) 124.91(16)
C(21)Sb(1)C(1) 116.86(16)
O(1)Sb(1)C(1)
C(1)Sb(1)C(31)
83.16(13)
94.64(15)
C(41)O(1)Sb(1) 131.7(3)
II
Sb(1)−O(1) 2.2613(15) O(1) Sb(1)C(31) 174.29(7)
Sb(1)−C(1) 2.114(2)
Sb(1)−C(11) 2.118(2)
Sb(1)−C(21) 2.116(2)
C(1)Sb(1)C(11) 119.13(9)
C(1)Sb(1)C(21) 128.67(9)
C(21)Sb(1)C(11) 109.81(9)
The average Sb–Ceq bond lengths are 2.123(4) Å
(I), 2.116(2) Å (II), 2.101(18) Å (III), and 2.118(2) Å
(IV). Axial Sb–Cax bonds are longer than equatorial
ones (2.195(4), 2.173(2), 2.144(17), and 2.148(2) Å in
I, II, III, and IV, respectively), and the ratios of Sb– Sb(1)−C(31) 2.173(2)
O(1)Sb(1)C(1)
83.94(7)
94.25(9)
Cax bond lengths to average Sb–Ceq bond lengths are
O(1)−C(41) 1.320(3) C(1)Sb(1)C(31)
1.034, 1.027, 1.020, and 1.014. The Sb–О distances in
complexes I, II, III, and IV are 2.117(3), 2.2613(15),
2.409(11), and 2.4296(15) Å, and the mentioned dis-
tance in complex I is shorter than Sb–Cax. Hence, the
series of tetraphenylantimony aroxides I–IV exhibits a
trend to distortion in the trigonal bipyramidal coordi-
nation of the central atom towards a tetrahedron. This
is indicated by an increase in the deviation of the anti-
mony atom from the equatorial plane in this series, a
decrease in the sum of equatorial angles, the trend of
the ratio Sb–Cax/(Sb–Ceq)av to unity, and the mono-
tonical elongation of Sb–О bonds.
C(41)O(1)Sb(1) 126.57(14)
III
Sb(1)−O(1) 2.409(11) O(1)Sb(1)C(31) 177.8(6)
Sb(1)−C(1) 2.107(17) C(11)Sb(1)C(1) 121.8(7)
Sb(1)−C(11) 2.094(18) C(11)Sb(1)C(21) 113.3(7)
Sb(1)−C(31) 2.144(17) C(21)Sb(1)C(1) 119.3(7)
Sb(1)−C(21) 2.102(18) C(11)Sb(1)C(31) 97.8(7)
Such a transformation in the coordination polyhe-
dron of the antimony atom can be explained by the
redistribution of electron density in the aroxy group
depending on the nature of substituents in it. The sub-
stituents with a negative inductive effect (bromine
and, especially, a nitro group) stabilize the phenolate
anion, increasing the contribution of the ionic com-
ponent to the Sb–О bond, which may be considered
as a coordination one in this case. On the contrary, the
presence of carbon radicals with a positive inductive
effect in the aroxy group does not produce any appre-
ciable shift of electron density from the oxygen atom.
In this case, the Sb–О bond has a covalent character
O(1)−C(41) 1.305(18) O(1)Sb(1)C(11)
83.9(5)
C(41)O(1)Sb(1) 133.9(9)
IV
Sb(1)−O(1) 2.4296(15) O(1)Sb(1)C(1)
174.01(7)
C(21)Sb(1)C(11) 119.63(8)
C(21)Sb(1)C(31) 118.40(8)
C(31)Sb(1)C(11) 114.96(8)
O(1) Sb(1)C(11) 84.33(7)
C(11)Sb(1)C(1) 99.65(8)
C(41)O(1)Sb(1) 131.61(14)
Sb(1)–C(1) 2.148(2)
Sb(1)–C(21) 2.106(2)
Sb(1)–C(11) 2.124(2)
(e.g., the length of this bond in complex I is compara- Sb(1)–C(31) 2.123(2)
ble with the sum of the antimony and oxygen covalent
O(1)–C(41) 1.278(3)
radii of 2.07 Å [10]). It is noteworthy that an increase
in the Sb–О distance in complexes I–IV is accompa-
nied by a decrease in the O–C bond length (1.337(5),
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SHARUTIN et al.
C(11)
C(55)
C(56)
C(45)
C(31)
C(1)
C(54)
C(53)
C(44)
O(1)
C(41)
Sb(1)
C(51)
C(52)
C(43) C(42)
C(21)
Fig. 1. Structure of complex I.
C(48)
C(1)
C(31)
C(11)
C(49)
C(45)
C(43)
C(47)
Br(1)
Sb(1)
C(46)
C(42)
C(41)
C(44)
C(21)
C(50)
O(1)
Br(2)
Fig. 2. Structure of complex II.
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TETRAPHENYLANTIMONY AROXIDES
299
O(3)
Br(1)
C(42)
C(1)
C(11)
C(43)
C(31)
Sb(1)
N(1)
C(41)
C(44)
C(45)
O(1)
O(2)
C(46)
C(21)
Br(2)
Fig. 3. Structure of complex III.
O(2)
C(11)
C(46)
C(45)
C(44)
N(1)
C(1)
Sb(1)
C(21)
C(41)
O(1)
C(43)
O(3)
C(31)
C(42)
N(2)
O(5)
O(4)
Fig. 4. Structure of complex IV.
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SHARUTIN et al.
Table 3. Selected parameters of the molecular structure of aroxy tetraphenylantimony compounds
Bond length, Å
O–CAr
Sum of angles
СeqSbCeq, deg
Complex
Reference
Sb–Cax
Sb–O
Ph4SbOC6H3(NO2)2-2,4 (IV)
Ph4SbOC6H2(Br2-2,6)(NO2-4) (III)
Ph4SbOC6H2Br3-2,4,6
2.4296(15)
2.409(11)
2.269(2)
2.2613(15)
2.224(2)
2.221(4)
2.143(4)
2.132(6)
2.128(3)
2.121(4)
2.117(3)
1.278(3)
1.305(18)
1.315(4)
1.320(3)
1.314(2)
1.317(6)
1.363(8)
1.41(2)
2.148(2)
2.144(17)
2.161(4)
2.173(2)
2.165(2)
2.181(5)
2.180(7)
2.176(8)
2.187(4)
2.194(6)
2.195(4)
352.99(8)
354.4(7)
356.86(8)
357.61(9)
357.07(9)
357.6(2)
358.5(3)
359.1(5)
359.2(9)
358.4(2)
358.47(16)
This work
This work
[1]
Ph4SbOC6H2(Br2-2,6)(t-Bu-4) (II)
Ph4SbOC6H4(NO2-4)
This work
[2]
Ph4SbOC6H4(NO2-2)
[3]
Ph4SbOC6H4(t-Bu-2)
[4]
Ph4SbOC6H3(Me2-2,6)
[5]
Ph4SbOC6H3(Me-2)(i-Pr-5)
Ph4SbOC6H3(t-Bu2-3,5)
Ph4SbOC6H4С6H7-4 (I)
1.333(5)
1.342(6)
1.337(5)
[5]
[6]
This work
3. V. V. Sharutin, V. V. Zhidkov, D. V. Muslin, et al., Izv.
Akad. Nauk, Ser. Khim., No. 5, 958 (1995).
1.320(3), 1.305(18), and 1.278(3) Å in complexes I, II,
III, and IV, respectively).
The revealed regularities are confirmed in the
series of the earlier structurally characterized tetrap-
henylantimony aroxides containing bromine, a nitro
group, and alkyl radicals in phenol residues (Table 3).
Hence, the distortion of the trigonal bipyramidal
configuration of molecules aroxy tetraaryl antimony
compounds and the elongation of the Sb–O bond are
due to the aroxy group having electron-drawing prop-
erties, which become stronger with an increase in the
number of electron-drawing substituents in the aro-
matic ring.
4. V. V. Sharutin, O. K. Sharutina, P. E. Osipov, et al.,
Russ. J. Coord. Chem. 27, 483 (2001).
5. V. V. Sharutin, O. K. Sharutina, P. E. Osipov, et al.,
Zh. Obshch. Khim. 67, 1528 (1997).
6. V. V. Sharutin, O. K. Sharutina, P. E. Osipov, et al.,
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SMART System (Bruker, Madison, Wisconsin, USA,
1998).
8. Bruker (1998). SHELXTL/PC. Versions 5.10. An Inte-
grated System for Solving, Refining and Displaying
Crystal Structures From Diffraction Data (Bruker,
Madison, Wisconsin, USA, 1998).
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