Synthesis and structure of 2-tert-butylphenoxytetraphenylantimony

Article abstract of DOI:10.1023/A:1011337615742

2-tert-Butylphenoxytetraphenylantimony Ph₄SbOC₆H₄(Bu-t)-2 was prepared by the reaction of pentaphenylantimony with 2-tert-butylphenol in toluene at 20°C. The structure of the obtained compound was determined by X-ray diffraction. The Sb atom in this compound has a distorted trigonal-bipyramidal coordination with the aroxy group in the axial position. The Sb-C(Ph)_eq and Sb-C(Ph)_ax distances are 2.111(7)-2.138(7) and 2.180(7) A; the Sb-O and O-C_Ar distances are 2.143(4) and 1.363(8) A, respectively. The C(Ph)_axSbO_Ar axial angle is 174.1(2)°, while the SbOC angle is 126.7(4)°.

Full text of DOI:10.1023/A:1011337615742

Russian Journal of Coordination Chemistry, Vol. 27, No. 7, 2001, pp. 483–485. Translated from Koordinatsionnaya Khimiya, Vol. 27, No. 7, 2001, pp. 518–520.
Original Russian Text Copyright © 2001 by Sharutin, Sharutina, Osipov, Platonova, Pakusina, Fukin, Zakharov.
Synthesis and Structure
of 2-tert-Butylphenoxytetraphenylantimony
V. V. Sharutin, O. K. Sharutina, P. E. Osipov, T. P. Platonova,
A. P. Pakusina, G. K. Fukin, and L. N. Zakharov
Blagoveshchensk State Pedagogical University, ul. Lenina 104, Blagoveshchensk, 675000 Russia
Institute of Organometallic Chemistry, Russian Academy of Sciences, ul. Tropinina 49, Nizhni Novgorod, 603600 Russia
Received July 3, 2000
Abstract—2-tert-Butylphenoxytetraphenylantimony Ph4SbOC6H4(Bu-t)-2 was prepared by the reaction of
pentaphenylantimony with 2-tert-butylphenol in toluene at 20°ë. The structure of the obtained compound was
determined by X-ray diffraction. The Sb atom in this compound has a distorted trigonal-bipyramidal coordina-
tion with the aroxy group in the axial position. The Sb–C(Ph)eq and Sb–C(Ph)ax distances are 2.111(7)–2.138(7)
and 2.180(7) Å; the Sb–O and O–CAr distances are 2.143(4) and 1.363(8) Å, respectively. The C(Ph)axSbOAr
axial angle is 174.1(2)°, while the SbOC angle is 126.7(4)°.
In continuation of our studies into the synthesis,
structure, and thermal decomposition of antimony
aroxytetraaryl compounds [1–3], we investigated the
interaction of pentaphenylantimony Ph5Sb with 2-tert-
butylphenol HOC6H4(Bu-t)-2. Reaction between the
reagents in the toluene solution at 20°ë run for 48 h
results in formation of 2-tert-butylphenoxytetraphenyl-
antimony (I) isolated from the reaction mixture as col-
orless crystals.
Ph5Sb + HOC6H4(Bu-t)-2
Ph4SbOC6H4(Bu-t)-2 + PhH.
The structure of compound I is determined by X-ray
diffraction. The coordination of the Sb(1) atom in the
Ph4SbOC6H4(Bu-t)-2 molecule is a distorted trigonal
bipyramid (figure), which is typical of pentavalent anti-
mony compounds with the coordination number 5. The
sum of the C(Ph)SbC(Ph) angles in the equatorial plane
C(16)
C(15)
C(17)
C(14)
C(18)
C(13)
C(27)
C(26)
O(1)
C(28)
C(29)
C(2)
C(1)
C(3)
C(6)
Sb(1)
C(4)
C(25)
C(11)
C(12)
C(32)
C(31)
C(19)
C(20)
C(21)
C(30)
C(5)
C(7)
C(8)
C(10)
C(33)
C(9)
C(24)
C(22)
C(34)
C(23)
Molecular structure of compound I.
1070-3284/01/2707-0483$25.00 © 2001 åÄIä “Nauka /Interperiodica”

484
SHARUTIN et al.
Table 1. The Sb–O and O–C bond lengths and SbOC angles in the molecules of antimony aroxytetraaryl compounds
Bond length, Å
Compound
SbOC angle, deg
References
Sb–O
O–CAr
Sb–Cax
Ph4SbOC6H4(NO2)-2
Ph4SbOC6H4(CHO)-4
Ph4SbOC6H3Me-2, i-Pr-5
Ph4SbOC6H4(t-Bu)-2
Ph4SbOC6H3(Me)2-2,6
2.221(4)
2.202(3)
2.128(3)
2.143(4)
2.132(6)
1.317(6)
1.321(5)
1.333(5)
1.363(8)
1.41(2)
2.181(5)
2.188(5)
2.187(4)
2.180(7)
2.176(8)
123.8(3)
126.9(3)
127.1(2)
126.7(4)
124.0(8)
[1]
[1]
[3]
In this work
[3]
is 358.5(3)°, and the OArSbC(Ph)ax angle is 174.1(2)°.
The equatorial positions are occupied by the Ph groups,
the C(Ph)eqSbC(Ph)eq angles vary in the 112.9(3)°–
125.0(3)° range. All the angles between the electroneg-
ative axial ligand and equatorial Ph groups are less than
90° (82.7(2)°, 86.3(2)°, and 88.8(2)°). The Sb–C(Ph)eq
distances varying in the 2.111(7)–2.138(7) Å range are
essentially shorter than the Sb–C(Ph)ax distance
2.180(7) Å. The OAr–C bond length is 1.363(8) Å; the
value of the Sb(1)O(1)C(25) angle is 126.7(4)°.
To date, the structures of four antimony aroxytet-
raphenyl compounds, containing electron-accepting [1]
and electron-donating [3] substituents in the aroxy
group, have been determined by X-ray diffraction
(Table 1).
As is seen from Table 1, the Sb–O distances for the
compounds with electron-donating substituents in the
aroxy group (2.128(3)–2.143(4) Å) are somewhat
shorter than the similar distances for the compounds
with electron-accepting substituents (2.202(3) and
2.221(4) Å). However, the O–CAr distances for the
compounds with electron-donating substituents in the
aroxy group (1.333(5)–1.41(2) Å) are somewhat longer
than similar distances for the compounds with electron-
accepting substituents (1.317(6) and 1.321(5) Å). Note
that the following regularity is found for the structures
of four compounds (except Ph4SbOC6H3Me-2,i-Pr-5):
the decrease of the O–CAr bond length is accompanied
by the increase of the Sb–O distance (Table 1). This fact
may be explained by a redistribution of electron density
in the system of conjugated Ar–O–Sb bonds involving
π-electrons of the benzene ring of the aroxy group, the
p-orbital of the oxygen atom, and the d-orbital of the
antimony atom. The electron-accepting substituent in
the aroxy group is responsible for the shift of electron
density from the oxygen atom to the benzene ring of the
aroxy group and for the strengthening of the O–C bond.
On the other hand, the electron-donating substituents
contained in the aroxy group make the electron density
shift from the oxygen atom to the antimony atom and
thus strengthen the Sb–O bond.
Table 2. Atomic coordinates (×104) and equivalent isotro-
pic thermal parameters (×103) in structure I
Atom
x
y
z
Ueq, Å2
Sb(1)
O(1)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
2375(1)
2834(4)
2086(6)
1818(8)
1582(9)
1614(8)
1885(10)
2128(8)
3644(7)
4653(7)
5383(8)
5121(10)
4140(11)
3436(9)
447(7)
1115(1)
1323(2)
962(4)
1517(4)
1449(5)
826(5)
6164(1)
7678(3)
4586(5)
3997(6)
3001(6)
2561(7)
3124(6)
4139(6)
5913(5)
5235(6)
4987(7)
5392(7)
6047(7)
6307(6)
6440(5)
5791(7)
5950(7)
6770(6)
7426(7)
7276(6)
6465(5)
6469(6)
6717(7)
6957(7)
6958(7)
6721(6)
8466(5)
8488(6)
9265(7)
10059(6)
10055(6)
9289(5)
9345(6)
9227(7)
10338(7)
8547(6)
37(1)
44(1)
39(2)
52(2)
65(2)
63(2)
66(3)
51(2)
41(2)
50(2)
59(2)
69(3)
71(3)
57(2)
40(2)
47(2)
55(2)
59(2)
69(3)
58(2)
39(2)
48(2)
62(2)
74(3)
73(3)
54(2)
40(2)
50(2)
59(2)
65(3)
59(2)
43(2)
56(2)
73(3)
87(3)
68(3)
265(5)
336(4)
1929(4)
1870(4)
2419(5)
3035(6)
3101(5)
2547(4)
1437(3)
1284(4)
1497(4)
1867(4)
2021(5)
1800(4)
106(3)
C(8)
C(9)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15) –1755(8)
C(16) –2031(8)
C(17) –1079(9)
C(18)
C(19)
C(20)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(27)
C(28)
C(29)
C(30)
C(31)
C(32)
C(33)
C(34)
–509(7)
166(8)
2951(7)
2039(9)
2409(11) –1051(5)
3657(11) –1184(5)
4547(10)
4205(8)
2603(7)
1560(8)
1350(9)
2195(10)
3188(9)
3449(7)
4538(8)
4007(9)
5258(9)
5532(7)
–410(4)
–689(5)
–42(4)
914(4)
480(4)
49(4)
66(5)
507(5)
954(4)
1462(4)
2176(4)
1440(6)
1315(5)
..
..
Ph4Sb
O
Ph4Sb
O
(CH3)3C
NO2
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 27 No. 7 2001

SYNTHESIS AND STRUCTURE
Table 3. Selected bond lengths and angles in structure I
485
Bond
d, Å
Angle
ω, deg
Angle
ω, deg
Sb(1)–C(7)
Sb(1)–C(19)
Sb(1)–C(13)
Sb(1)–O(1)
Sb(1)–C(1)
O(1)–C(25)
2.111(7)
2.125(7)
2.138(7)
2.143(4)
2.180(7)
1.363(8)
C(7)Sb(1)C(19)
C(7)Sb(1)C(13)
C(19)Sb(1)C(13)
C(7)Sb(1)O(1)
C(19)Sb(1)O(1)
C(13)Sb(1)O(1)
125.0(3)
112.9(3)
120.6(6)
82.7(2)
86.3(2)
88.8(2)
C(7)Sb(1)C(1)
C(19)Sb(1)C(1)
C(13)Sb(1)C(1)
O(1)Sb(1)C(1)
C(25)O(1)Sb(1)
91.7(2)
95.4(3)
95.1(3)
174.1(2)
126.7(4)
EXPERIMENTAL
located from the difference syntheses and refined iso-
tropically. The H atoms of the tert-butyl groups were
placed in the geometrically calculated positions and
refined in the rider model with fixed values of Uiso. All
calculations were performed using the SHELX97 pro-
gram package [4] on an IBM PC.
Atomic coordinates and equivalent isotropic ther-
mal parameters are listed in Table 2. Bond lengths and
angles are given in Table 3.
Synthesis of 2-tert-butylphenoxytetraphenylanti-
mony (I). A mixture of 1.00 g (2.0 mmol) of pentaphe-
nylantimony, 0.30 g (2.0 mmol) of 2-tert-butylphenol,
and 10 ml of toluene was kept for 48 h at 25°ë, after
which crystals were formed; their quantity increased
significantly on cooling the reaction mixture to −18°ë.
The solvent was decanted; the crystals were washed
with hexane (5 ml) and dried. The yield was 0.96 g
(84%), mp 211°ë.
ACKNOWLEDGMENTS
For C34H33OSb
The work was supported by the Russian Foundation
for Basic Research, project no. 96-15-97455, and the
Center for X-ray Structural Studies at the Department
of General and Technical Chemistry of the Russian
Academy of Sciences.
anal. calcd. (%): C, 70.47;
Found (%): C, 69.49;
H, 5.70;
H, 5.32;
Sb, 21.07.
Sb, 21.25.
X-ray diffraction analysis of I was carried out
using a Siemens P3/PC four-circle diffractometer
(graphite monochromator, MoKα radiation, θ/2θ scan
mode).
REFERENCES
The crystals of I are monoclinic: a = 10.395(3) Å, b =
19.798(9) Å, c = 13.556(5) Å, β = 90.36(3)°, V =
1. Sharutin, V.V., Zhidkov, V.V., Muslin, D.V., et al., Izv.
Akad. Nauk, Ser. Khim., 1995, no. 5, p. 958.
2. Sharutin, V.V., Sharutina, O.K., Osipov, P.E., et al.,
Zh. Obshch. Khim., 1997, vol. 67, no. 6, p. 1035.
2790(2) Å3, space group P2(1)/n, Z = 4, ρcalcd
=
1.379 g/cm3 at 20°C.
The structure of complex I was solved by the direct
method and refined by the full-matrix least-squares
method in the anisotropic approximation for all non-
hydrogen atoms. The refinement converged to R =
0.046, Rw = 0.107, and S = 1.22 for 2842 reflections
with I > 2σ(I). The H atoms of the phenyl groups were
3. Sharutin, V.V., Sharutina, O.K., Osipov, P.E., et al.,
Zh. Obshch. Khim., 1997, vol. 67, no. 9, p. 1528.
4. Robinson, W.T. and Sheldrick, G.M., Crystallographic
Computing: Techniques and New Technologies, Isaacs,
N.W. and Taylor, M.R., Eds., Oxford: Oxford Univ.
Press, 1988.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 27 No. 7 2001