Russian Journal of Coordination Chemistry, Vol. 27, No. 9, 2001, pp. 669–675. Translated from Koordinatsionnaya Khimiya, Vol. 27, No. 9, 2001, pp. 710–716.
Original Russian Text Copyright © 2001 by Sharutin, Sharutina, Senchurin, Platonova, Nasonova, Pakusina, Gerasimenko, Sergienko.
m-Oxo-Bis(Tetraphenylantimony):
Synthesis, Structure, and Reactions
V. V. Sharutin, O. K. Sharutina, V. S. Senchurin, T. P. Platonova, N. V. Nasonova, A. P. Pakusina,
A. V. Gerasimenko, and S. 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 February 13, 2001
Abstract—Heating of a solution of pentaphenylantimony in toluene in atmospheric oxygen affords µ-oxo-
bis(tetraphenylantimony) (I) in a 63% yield. The latter compound can be converted to bis(tetraphenylantimony)
carbonate or phthalate by the action of carbon dioxide or phthalic anhydride, respectively. According to X-ray
diffraction data, the antimony atoms in compound I have a distorted trigonal-bipyramidal coordination (Sb–O
2.0050(4) Å, the SbOSb angle 151.71(9)°). The molecule of bis(tetraphenylantimony) phthalate is composed
of two equal fragments, and its Sb atoms also have trigonal-bipyramidal coordination (Sb–O 2.2421(8) Å; Sb–
C 2.176(1), 2.115(1), 2.130(1), and 2.137(1) Å).
The structures of binuclear antimony(V) oxo com- The Sb–Obr bond in I (2.0050(4) Å) is somewhat longer
plexes (R3SbX)2O (X is an electronegative ligand) con- than that in other structurally characterized antimony
taining a bridging oxygen atom were described in [1– complexes containing a bridging O atom, but it is
11]. As a rule, the antimony atoms in these compounds shorter than the sum of the covalent radii of the Sb and
have trigonal-bipyramidal coordination. The SbOSb O atoms (2.07 Å) [14]. The abnormally short Sb–Cterm
angles most often range from 135° to 160° [1, 3, 5, 7, 9, distances and the longest Sb–O bonds in compound I
11], but in some cases, they are close to 180° [2, 4, 8, compared to other phenyl derivatives of the
11]. Depending on the type of terminal ligand, the Sb– (Ph3SbX)2O type (X= Cl, Br, I, NO3, OSO2R, etc.) are
X bond length can vary widely, usually being longer due to a low withdrawing power of the terminal phenyl
than the sum of the covalent radii of the Sb and X ligand. Because of this, the positive charge on the anti-
atoms. The distances between the antimony atoms and mony atoms decreases and the lone electron pairs of the
the bridging O atom are always shorter than the sum of O atom cannot interact effectively with the vacant d
the covalent radii of the Sb and O atoms, which is orbitals of antimony. The Sb–Ceq bond lengths in com-
explained by the interaction of the lone electron pairs of pound I (2.131(2)–2.133(2) Å) are approximate to the
the oxygen atom with vacant d orbitals of antimony corresponding distances in other phenyl compounds of
[10–13]. Note that the terminal ligand X in all structur- antimony(V). However, the Sb–Cax bond (2.225(2) Å)
ally characterized (R3SbX)2O compounds is bound to in compound I is longer than the analogous distances in
the antimony atom through an electronegative atom; no all structurally characterized antimony complexes with
antimony derivatives with the terminal ligand attached a general formula R4SbX and a trigonal-bipyramidal
to antimony via the carbon atom are known.
configuration.
Complex I in toluene reacts with carbon dioxide
(20°ë, 24 h) or with phthalic anhydride (100°ë, 1 h) to
give bis(tetraphenylantimony) carbonate or phthalate
(II), respectively:
µ-Oxo-bis(tetraphenylantimony(V)) (I) was synthe-
sized by oxidizing a toluene solution of pentaphenylan-
timony with atmospheric oxygen:
2Ph5Sb + O2
(Ph4Sb)2O.
(Ph4Sb)2O + CO2
(Ph4Sb)2CO3,
Compound I is a V-shaped dimer. The antimony
atoms are bridged by the O atom lying on axis 2
(Fig. 1). The SbOSb bond angle is equal to 151.71(9)°.
The antimony atoms have a distorted trigonal-bipyra-
midal coordination. The equatorial CSbC bond angles
(Ph4Sb)2O + C6H4C2O3
C6H5CH3
ortho-C6H4[C(O)OSbPh4]2 C6H5CH3.
According to the X-ray diffraction data, the anti-
vary from 116.73(7)° to 123.07(8)°, while the axial mony atoms in bis(tetraphenylantimony) phthalate (II)
OSbC angle is 173.92(7)° (Table 1). The Sb–Ceq dis- have trigonal-bipyramidal coordination typical of Sb
tances equal 2.131(2)–2.133(2) Å, i.e., they are sub- complexes with C.N. 5 (Fig. 2). Compound II is built
stantially shorter than the Sb–Cax bond (2.225(2) Å). from two equal fragments; when rotated about axis 2
1070-3284/01/2709-0669$25.00 © 2001 åÄIä “Nauka /Interperiodica”
Sharutin
