Tris(2,6-di-tert-butyl-4-methylphenolato-O)(triphenylphosphine oxide-O)-samarium(III)

Article abstract of DOI:10.1107/S0108270100010192

The crystal structure of [Sm(C₁₅H₂₃O)₃(C₁₈H₁₅OP)] consists of one Sm atom, three aryloxo ligands and one triphenylphosphine oxide molecule. The Sm atom is coordinated by four O atoms, resulting in a distorted tetrahedral geometry. The coordination geometry around the central metal atom has a distorted trigonal-bipyramidal stereochemistry as a result of intramolecular π-bonding.

Full text of DOI:10.1107/S0108270100010192

metal-organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
by four O atoms, resulting in a distorted tetrahedral geometry.
The coordination geometry around the central metal atom is
similar to that in [Sm(OAr)3(thf)]Áthf (Qi et al., 1995), but
different from that in [Nd(Odpp)3(thf)], which has a distorted
trigonal±bipyramidal stereochemistry as a result of intra-
molecular ꢀ-bonding (Deacon et al., 1995).
ISSN 0108-2701
Tris(2,6-di-tert-butyl-4-methylphenol-
ato-O)(triphenylphosphine oxide-O)-
samarium(III)
The ÆOÐSmÐO of the three aryloxo O atoms around
samarium is 345.0ꢁ; this value is comparable with those in
[Sm(OAr)3(thf)]Áthf (351.9ꢁ; Qi et al., 1995) and
[Nd(Odpp)3(thf)] (353.2ꢁ). However, the three OArÐSmÐ
OAr bond angles range from 99.42 (8) to 138.29 (8)ꢁ; this is
different from the case in [Sm(OAr)3(thf)]Áthf, where the
three bond angles are nearly equal, and this may be attributed
to the presence of the triphenylphosphine oxide ligand which
is more bulky than the tetrahydrofuran ligand. The three SmÐ
OArÐC bond angles range from 172.9 (2) to 175.3 (2)ꢁ; they
are all somewhat larger than those in [Sm(OAr)3(thf)]Áthf (Qi
et al., 1995) and are comparable with those in
[Sm(OAr)2(thf)3]Áthf (Qi et al., 1994) and [La(OC6H3Me2-
2,6)3{MeO(CH2CH2O)4Me}] (Aspinall & Williams, 1996). The
SmÐOÐP angle of 170.06 (14)ꢁ is comparable with those
found for lanthanide±triphenylphosphine oxide complexes
(Evans et al., 1985; Deacon et al., 1989).
Yingming Yao,a Qi Shena* and Kaibei Yub
aDepartment of Chemistry, Suzhou University, Suzhou 215006, People's Republic of
China, and bChengdu Institute of Organic Chemistry, Chengdu 610041, People's
Republic of China
Correspondence e-mail: qshen@suda.edu.cn
Received 4 July 2000
Accepted 20 July 2000
In the title complex, [Sm(C15H23O)3(C18H15OP)], the central
metal atom is coordinated by three O atoms of the aryloxo
ligands and by one O atom of the triphenylphosphine oxide
molecule resulting in a distorted tetrahedral geometry. The
SmÐOAr distances (Ar is aryl) range from 2.122 (2) to
The three SmÐOAr bond lengths range from 2.112 (2) to
Ê
2.190 (2) A, with an average of 2.155 A; this value is similar to
Ê
Ê
Ê
2.190 (2) A and the SmÐOPPh bond length is 2.306 (2) A.
Ê
3
that of [Sm(OAr)3(thf)]Áthf (2.151 A; Qi et al., 1995).
Subtraction of the estimated radius for four-coordinate
Ê
trivalent samarium (0.84 A; Shannon, 1976) from the SmÐO
Comment
Ê
distance gives a value of 1.31 A, which is in the range 1.24±
In recent years, lanthanide aryloxides have found a variety of
applications as homogeneous catalysts for organic reactions
(Shibasaki et al., 1997), and as precursors for organolanthan-
ide syntheses (Clark et al., 1994) and high purity oxide mate-
rials (Hubert-Pfalzgraf, 1995). The syntheses, structures and
reactivities of aryloxo±lanthanide complexes have attracted a
great deal of attention and the investigation of the chemistry
of lanthanide complexes containing aryloxo ligands has
produced complexes exhibiting a variety of structural types
(Evans et al., 1997; Deacon et al., 1997). In our study of the
syntheses and reactivities of lanthanide aryloxides (Qi et al.,
1995; Yao et al., 1998), the title complex, (I), was obtained
from the reaction of [(ArO)2Sm(thf)3] (ArO = OC6H2-2,6-di-
tert-butyl-4-Me and thf is tetrahydrofuran) with excess tri-
phenylphosphine oxide in toluene.
Ê
1.31 A found for a similar treatment of LnÐOAr distances in
The crystal structure determination indicates that (I)
consists of one Sm atom, three aryloxo ligands and one tri-
phenylphosphine oxide molecule. The Sm atom is coordinated
Figure 1
The molecule of (I) showing 40% probability displacement ellipsoids. H
atoms have been omitted for clarity.
ꢀ
1330 # 2000 International Union of Crystallography Printed in Great Britain ± all rights reserved
Acta Cryst. (2000). C56, 1330±1331

metal-organic compounds
Table 1
Selected geometric parameters (A, ).
other aryloxo±lanthanide complexes (Hitchcock et al., 1983,
Ê
1987). The SmÐOPPh distance of 2.306 (2) A is comparable
ꢁ
Ê
3
with
the
values
in
[(C5Me5)2{(C6H5)3PO}Sm]2(ꢁ-
SmÐO4
SmÐO2
SmÐO3
2.112 (2)
2.163 (2)
2.190 (2)
SmÐO1
PÐO1
2.306 (2)
1.509 (2)
OCH CHO) (Evans et al., 1985) and [(C5H5)2Yb(OPPh3)2]
(Deacon et al., 1989) if the difference in the ionic radii is
considered.
O4ÐSmÐO2
O4ÐSmÐO3
O2ÐSmÐO3
O4ÐSmÐO1
O2ÐSmÐO1
99.42 (8)
107.30 (8)
138.29 (8)
127.73 (8)
93.36 (8)
O3ÐSmÐO1
PÐO1ÐSm
C19ÐO2ÐSm
C34ÐO3ÐSm
C49ÐO4ÐSm
94.86 (8)
170.06 (14)
174.3 (2)
172.9 (2)
175.3 (2)
Experimental
The title complex is very sensitive to air and moisture. Consequently,
all manipulations were carried out under argon by Schlenk techni-
ques. Crystals were obtained from the reaction of [Sm(OAr)2(thf)3]
with excess triphenylphosphine oxide in toluene at 353 K, followed
by crystallization from a toluene solution at 263 K. A crystal suitable
for single-crystal structure determination was sealed in a thin-walled
glass capillary.
used to re®ne structure: SHELXL93 (Sheldrick, 1993); molecular
graphics: SHELXTL; software used to prepare material for publi-
cation: SHELXTL.
We thank the Natural National Science Foundation of
China, the Natural Science Foundation of Jiangsu Province
and Suzhou University for the ®nancial support.
Crystal data
3
[Sm(C15H23O)3(C18H15OP)]
Mr = 1086.62
Monoclinic, P21/n
Dx = 1.231 Mg m
Mo Kꢃ radiation
Cell parameters from 38
re¯ections
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: SK1411). Services for accessing these data are
described at the back of the journal.
Ê
a = 11.682 (2) A
b = 38.168 (6) A
ꢄ = 2.99±16.50ꢁ
ꢁ = 1.072 mm
T = 297 (2) K
Ê
1
Ê
c = 14.245 (2) A
ꢂ = 112.630 (10)ꢁ
Ê
V = 5862.5 (16) A
Z = 4
3
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=
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Ê
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Ê
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Extinction correction: SHELXL93
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644 parameters
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Áꢆmin
=
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Ê
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È
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ꢀ
Acta Cryst. (2000). C56, 1330±1331
Yao, Shen and Yu [Sm(C15H23O)3(C18H15OP)] 1331