Synthesis of new titanatranes containing organic substituents in the atrane fragment

Article abstract of DOI:10.1007/s11172-006-0197-z

Titanatrane CpTi(OCH(CH₃)CH₂)₃N (3) was prepared by the reaction of CpTiCl₃ with N(CH₂CH(CH ₃)OH)₃ in the presence of triethylamine. The reaction of CpTi(OMe)₃ (8) with N(CH₂CH₂OH) ₂(CH₂CHPhOH), erythro-N(CH₂CH ₂OH)₂(CHPhCHPhOH), and N(CH₂CH ₂OH)₂(CH₂CPh₂OH) gave cyclopentadienyltitanatranes 12-14. Compound 8 reacts with threo-N(CH ₂CH₂OH)₂(CHPhCHPhOH) to give a mixture of threo-CpTi(OCH₂CH₂)₂(OCHPhCHPh)N and threo-MeOTi(OCH₂CH₂)₂(OCHPhCHPh)N. Slow hydrolysis of the latter product gave threo-[Ti₃O(OMe){(OCH ₂CH₂)_2- (OCHPhCHPh)N} ₃] ₂, which was studied by X-ray diffraction analysis. The crystal structures of 3 and 12 were also determined by X-ray diffraction analysis. The titanium coordination polyhedron in these complexes is a distorted trigonal bipyramid in which the equatorial positions are occupied by three oxygen atoms and the axial positions contain the N atom and the Cp group. The titanium-nitrogen distances (2.313(2), 2.291(2) A in two independent molecules of 3 and 2.271(2) A in compound 12) confirm the presence of Ti←N transannular interaction.

Full text of DOI:10.1007/s11172-006-0197-z

Russian Chemical Bulletin, International Edition, Vol. 54, No. 12, pp. 2831—2840, December, 2005
2831
Synthesis of new titanatranes containing organic substituents
in the atrane fragment
K. V. Zaitsev,aꢀ S. S. Karlov,a M. V. Zabalov,a A. V. Churakov,b G. S. Zaitseva,a and D. A. Lemenovskiia
aDepartment of Chemistry, M. V. Lomonosov Moscow State University,
1 Leninskie Gory, 119992 Moscow, Russian Federation.
Fax: +7 (495) 932 8846. Eꢀmail: zvkir@mail.ru
bN. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
31 Leninsky prosp., 119991 Moscow, Russian Federation.
Fax: +7 (495) 954 1279
Titanatrane CpTi(OCH(CH3)CH2)3N (3) was prepared by the reaction of CpTiCl3 with
N(CH2CH(CH3)OH)3 in the presence of triethylamine. The reaction of CpTi(OMe)3 (8) with
N(CH2CH2OH)2(CH2CHPhOH),
N(CH2CH2OH)2(CH2CPh2OH) gave cyclopentadienyltitanatranes 12—14. Compound 8
reacts with threoꢀN(CH2CH2OH)2(CHPhCHPhOH) to give mixture of
erythroꢀN(CH2CH2OH)2(CHPhCHPhOH),
and
a
threoꢀCpTi(OCH2CH2)2(OCHPhCHPh)N and threoꢀMeOTi(OCH2CH2)2(OCHPhCHPh)N.
Slow hydrolysis of the latter product gave threoꢀ[Ti3O(OMe){(OCH2CH2)2ꢀ
(OCHPhCHPh)N}3]2, which was studied by Xꢀray diffraction analysis. The crystal structures
of 3 and 12 were also determined by Xꢀray diffraction analysis. The titanium coordination
polyhedron in these complexes is a distorted trigonal bipyramid in which the equatorial posiꢀ
tions are occupied by three oxygen atoms and the axial positions contain the N atom and the
Cp group. The titanium—nitrogen distances (2.313(2), 2.291(2) Å in two independent molꢀ
ecules of 3 and 2.271(2) Å in compound 12) confirm the presence of Ti←N transannular
interaction.
Key words: titanatranes, trialkanolamines, transalkoxylation, transannular interaction, Xꢀray
diffraction analysis.
The chemistry of metallatranes, cyclic ethers of
trialkanolamines, has been vigorously developing during
the last fifty years. Derivatives of most of chemical eleꢀ
ments have now been synthesized. The interest in these
unusual compounds is due to the possible formation of an
intramolecular coordination bond, which changes subꢀ
stantially the structure and properties of metallatranes
compared to the structures and properties of their close
analogs, trisꢀalkoxides in which this type of intramolecuꢀ
lar interaction is missing. In particular, well known is a
higher stability of metallatranes against hydrolysis. Thereꢀ
fore, metallatranes may prove more promising from the
applied standpoint1 compared to other metal compounds.
The compounds of main group elements, especially
silatranes and germatranes, possessing a broad spectrum
of biological activities, have been studied in most deꢀ
tail.2,3 Transition metal compounds have been much less
studied,4—6 although they could find a broad application,
for example, as catalysts for various organic reactions. It
is of interest to compare the structures and properties of
transition metal atranes with those of the related comꢀ
pounds formed by nontransition elements; this may proꢀ
vide additional information on the nature of the eleꢀ
ment—nitrogen transannular bond in this type of comꢀ
pound.
In this paper we consider titanatranes, which are strucꢀ
tural analogs of wellꢀstudied silatranes and germatranes.
Although the first representatives of titanatranes were synꢀ
thesized back in the 1960s,7—9 and in recent decade, the
interest in these derivatives has increased,10—14 at most
20 publications on this topic are known. The attention
was focused on the specific features of the structure15—17
and catalytic properties of chiral trialkanolamine comꢀ
plexes in the polymerization of olefins and lactide18—20
and oxidation of sulfides.21—25 A broad range of titanꢀ
atranes containing various cyclopentadienyl substituents
(Cp*, C5Me4H, C5Me4Et, C5Me4Ph и C5Me4Tol) at the
titanium atom and the Ph and Me groups at the carbon
atoms of the atrane skeleton have been reported.26—28
The atranes were synthesized by the reaction of the correꢀ
sponding trichloro(η5ꢀ2,4ꢀcyclopentadienꢀ1ꢀyl)titanium
with trialkanolamine in the presence of Et3N. The cataꢀ
lytic properties of the obtained compounds were studied
in styrene polymerization; the structures of six cycloꢀ
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2736—2744, December, 2005.
1066ꢀ5285/05/5412ꢀ2831 © 2005 Springer Science+Business Media, Inc.

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Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005
Zaitsev et al.
pentadienyl derivatives were determined by Xꢀray diffracꢀ
tion. By the beginning of our study, only one titanatrane
containing the unsubstituted cyclopentadienyl ring,
N(CH2CH2O)3TiCp, has been described in the literature.
This compound was prepared both by the reaction of
CpNa with N(CH2CH2O)3TiCl10 and by transalkoxyꢀ
lation with CpTi(OMe)3 and triethanolamine.11
titanatranes was investigated by quantum chemical methꢀ
ods. Of particular interest for estimation of the effect of
substituents in the Cp ring on the titanium—nitrogen
transannular interaction was to compare the structures of
compounds we synthesized with the data26—28 obtained
previously for related compounds.
This paper reports the synthesis and studies of the
structure of cyclopentadienyltitanatranes containing difꢀ
ferent substituents at the carbon atoms of the atrane skelꢀ
eton. The structures of two compounds were established
by Xꢀray diffraction. The nature of the Ti←N bond in
Results and Discussion
For the synthesis of titanatranes, we tested sevꢀ
eral methods for the formation of the atrane skeleton
(Schemes 1—4). The reaction of trichloride 1 with
Scheme 1
Scheme 2
9, 12: R = H, R´ = Ph
10, 13: R = Ph, R´ = Ph (erythro)
11, 14: R = H, R´ = R″ = Ph

Titanatranes substituted in the atrane framework
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005 2833
Scheme 3
resulting from cleavage of the Ti—Cp bond by methanol
evolved during the reaction. This outcome is apparently
due to the low solubility of initial trialkanolamine 15. On
longꢀterm keeping of a solution of compound 17 (diꢀ
chloromethane—nꢀheptane) in air, hydrolysis takes place,
giving rise to the Ti—O bonds in titanatrane 18, which
crystallizes as a hexanuclear structure. The structures of
two closely related titanatranes, which also contain six
titanium atoms in the molecule, have been studied previꢀ
ously17 by Xꢀray diffraction analysis. Apparently, the forꢀ
mation of hexameric titanatranes in hydrolysis under mild
conditions is a general feature of titanium compounds
with trialkanolamines.
The attempts to extend these two methods for generaꢀ
tion of the titanatrane moiety to the synthesis of indenylꢀ
and fluorenyltitanatranes failed; however, we were able to
isolate known compounds 20 23 and 22 12 in high yields
(see Scheme 3). The results of these reactions are consisꢀ
tent with the known data29 indicating a higher lability of
the Ti—C bond in the indenylꢀ and fluorenyltrialkoxyꢀ
titanium derivatives compared to the cyclopentadienyl
derivatives.
Scheme 4
We also studied other approaches to the synthesis of
titanatranes based on the reactions of titanium trichlorides
1 and 4 with Na, Li, and Me3Si trialkanolamine derivaꢀ
tives (see Scheme 4). The reaction of trichloride 1 with
triethanolamine trisodium salt (23) furnished atrane 7
described previously12 in a moderate yield. However, the
reaction of the trilithium salt 24 with trichloride 4 reꢀ
sulted in a mixture of poorly identifiable products. Treatꢀ
ment of complex 4 with ether 25 did not give compound 6
either; according to 1H NMR data, refluxing of the reacꢀ
tant mixture in xylene yields the compound [(Me3Siꢀη5ꢀ
C5H4)TiCl3•N(CH2CH2OSiMe3)3]. Previously, the
formation of
a similar donorꢀacceptor complex
[BHal3•MeN(CH2CH2OSiMe3)2] was detected in the reꢀ
actions of boron compounds.30
Thus, the procedure of choice for the synthesis of a
particular cyclopentadienyltitanatrane depends on both
the substituents in the Cp ring and the trialkanolamine
structure.
triisoropanolamine (2) in the presence of Et3N gave
titanatrane 3 in a high yield (see Scheme 1). Quite an
unexpected result was obtained on an attempt to extend
the scope of this reaction. Treatment of trichloride 4,
containing a Me3Si group in the Cp ring, with triethanolꢀ
amine (5) gave not only the expected atrane 6 but also
desilylated complex 7 (the ratio 6 : 7 = 7 : 3). In this case,
desilylation can be induced by either triethanolamine (5),
which is converted into monotrimethylsilyl ether, or by
HCl (from Et3N•HCl).
Transalkoxylation (see Scheme 2) of trimethoxy(η5ꢀ
2,4ꢀcyclopentadienꢀ1ꢀyl)titanium (8) with trialkanolꢀ
amines 9—11 afforded titanatranes 12—14 in high yields.
However, the reaction of alkoxide 8 with trialkanolamine
15 (threoꢀconfiguration of the phenyl groups) affords not
only the expected complex 16, but also compound 17,
The structures of the previously unknown cycloꢀ
pentadienyltitanatranes 3, 6, 12—14, and 16 and comꢀ
1
pound 17 were confirmed by H and 13C NMR spectrosꢀ
copy and, in some cases, by mass spectrometry. Titanꢀ
atranes bearing substituents in the atrane fragment have
one or several chiral centers, which accounts for the forꢀ
mation of the corresponding isomers. Atrane 3 is formed
as a mixture of two diastereomers differing in the arrangeꢀ
ment of three Me groups relative to the titanium—nitroꢀ
gen bond axis.2 Compounds 13, 16, and 17 were obtained
as one diastereomer pair.
The structures of compounds 3, 12, and 18 were esꢀ
tablished by Xꢀray diffraction (Fig. 1—3, Tables 1 and 2).
The quality of crystals 18 proved unsatisfactory for

2834
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005
Zaitsev et al.
C(2)
C(1)
C(2)
C(3)
C(4)
C(1)
C(5)
C(3)
C(5)
C(4)
O(1)
O(3)
C(33)
Ti(1)
O(2)
Ti
N
C(18)
C(17)
O(2)
C(22)
C(13)
C(12)
O(3)
O(1)
C(32)
C(12)
C(16)
C(31)
C(14)
C(15)
C(22)
C(23)
C(11)
C(32)
C(13)
N(1)
C(11)
C(21)
C(31)
C(21)
Fig. 1. Molecular structure of complex 3 (one crystallographiꢀ
cally independent molecule).
Fig. 2. Molecular structure of complex 12.
C(1)
N(1)
O(31)
O(23)
O(3)
O(12)
Ti(3)
O(32)
O(13)
Ti(2)
O(33)
O(11)
N(3)
Ti(1)
O(22)
O(21)
N(2)
O(2)
O(2A)
N(2A)
O(11A)
Ti(1A)
O(21A)
Ti(2A)
O(22A)
N(3A)
O(33A)
O(13A)
O(32A)
Ti(3A)
O(12A)
O(23A)
O(3A)
O(31A)
N(1A)
C(1A)
Fig. 3. Molecular structure of complex 18.

Titanatranes substituted in the atrane framework
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005 2835
Table 1. Selected interatomic distances (d) in structures 3 and 12
stituents in the atrane core are monomeric in the crysꢀ
tal. The titanium—nitrogen distances in titanatranes
(monomers and dimers) occur in the range of
2.255(3)—2.427(8) Å,18,23 this bond length being indeꢀ
pendent of the coordination number of the titanium atom.
Bond
d/Å
Bond
d/Å
Compound 3*
Compound 3*
Ti(1)—O(1)
Ti(1)—O(2)
Ti(1)—O(3)
Ti(2)—O(4)
Ti(2)—O(5)
Ti(2)—O(6)
1.8816(14)
1.8804(13)
1.8983(13)
1.8905(14)
1.8816(14)
1.8931(13)
Ti(2)—C(7)
Ti(2)—C(8)
Ti(2)—C(9)
2.3894(18)
2.3824(17)
2.4277(17)
Comparison of the titanatrane and silatrane structures
indicates that the length of the titanium—nitrogen bond
depends on the nature of the substituent at the titanium
atom to a lesser extent than the silicon—nitrogen bond
length.31 Conversely, the Ti—Oeq bonds in monomeric
titanatranes are more susceptible to the influence of
the axial substituent (S,S,SꢀN(CH2CHMeO)3TiCl,
Ti(2)—C(10) 2.4513(18)
Compound 12
Ti—O(1)
Ti—O(2)
Ti—O(3)
Ti—N
Ti—C(1)
Ti—C(2)
Ti—C(3)
Ti—C(4)
Ti—C(5)
1.883(2)
1.880(2)
1.886(2)
2.271(2)
2.431(3)
2.433(3)
2.454(3)
2.436(3)
2.418(3)
Ti(1)—N(1) 2.3129(15)
Ti(2)—N(2) 2.2910(15)
Ti(1)—C(1)
Ti(1)—C(2)
Ti(1)—C(3)
Ti(1)—C(4)
Ti(1)—C(5)
Ti(2)—C(6)
2.4299(18)
2.4385(19)
2.4428(19)
2.4455(18)
2.4480(18)
2.4454(19)
1.800(2)—1.813(2)
Å;23
SꢀN(CH2CHMeO)ꢀ
(CH2CH2O)2TiCp*, 1.873(5)—1.888(5) Å (see Ref. 27))
than the Si—Oeq bonds in silatranes.31 These facts can be
attributed to different ways of formation of the additional
bond in the atranes. Indeed, complexes of dꢀelements
tend to experience strong donor—acceptor interaction,
whereas in the case of pꢀelements, the transannular bond
can be considered as a hypervalent bond, its length varyꢀ
ing over a broad range depending on the nature of the
substituent at the element atom.
The titanium coordination polyhedron in atranes 3
and 12 is a distorted trigonal bipyramid in which the
equatorial positions are occupied by three oxygen atoms,
and the axial positions, by the nitrogen atom and the
Cp group. The titanium—nitrogen distances (2.313(2),
2.291(2) Å in two independent molecules of complex 3;
2.271(2) Å in complex 12) attest unambiguously to the
presence of Ti←N interaction in these compounds.
The Ti—C bond lengths are in the 2.430(2)—2.448(2)
and 2.382(2)—2.451(2) Å ranges (for the two indeꢀ
pendent molecules in the crystal of 3) and in the
2.418(3)—2.454(3) Å range (in complex 12). Titanatranes
* Two independent molecules.
discussing structural details; however, the mutual posiꢀ
tions of the atoms were determined unambiguously.
By the beginning of this work, the structures of
18 titanatranes have been studied by Xꢀray diffraction
analysis. Of these, fifteen contain N(CH2CH2O)3Ti group,
while the other ones, viz., S,S,SꢀN(CH2CHMeO)3TiCl,
S,S,SꢀN(CH2CHMeO)3TiCp*, and SꢀN(CH2CHMeO)ꢀ
(CH2CH2O)2TiCp* (Cp* is pentamethylcyclopentaꢀ
dienyl), contain substituents in the atrane core. The comꢀ
pounds N(CH2CH2O)3TiХ (Х = OPri, OAc, NMe2, SPri,
OBut) crystallize as dimers in which the Ti atom has a
coordination number equal to six due to the additional
bridging type bond with the oxygen atom of the atrane
core of a second molecule. All titanatranes with subꢀ
Table 2. Selected bond angles (ω) in structures 3 and 12
3*
12
Angle
ω/deg
Angle
ω/deg
Angle
ω/deg
O(2)—Ti(1)—O(1)
O(2)—Ti(1)—O(3)
O(1)—Ti(1)—O(3)
O(2)—Ti(1)—N(1)
O(1)—Ti(1)—N(1)
O(3)—Ti(1)—N(1)
C(21)—N(1)—C(11)
C(21)—N(1)—C(31)
C(11)—N(1)—C(31)
C(21)—N(1)—Ti(1)
C(11)—N(1)—Ti(1)
C(31)—N(1)—Ti(1)
C(12)—O(1)—Ti(1)
C(22)—O(2)—Ti(1)
C(32)—O(3)—Ti(1)
116.69(6)
111.86(6)
113.75(6)
75.56(5)
75.34(6)
76.21(6)
112.86(16)
111.79(15)
111.67(15)
106.31(11)
107.35(11)
106.39(11)
126.68(12)
126.30(11)
124.71(11)
O(5)—Ti(2)—O(4)
O(5)—Ti(2)—O(6)
O(4)—Ti(2)—O(6)
O(5)—Ti(2)—N(2)
O(4)—Ti(2)—N(2)
O(6)—Ti(2)—N(2)
C(61)—N(2)—C(41)
C(61)—N(2)—C(51)
C(41)—N(2)—C(51)
C(61)—N(2)—Ti(2)
C(41)—N(2)—Ti(2)
C(51)—N(2)—Ti(2)
C(42)—O(4)—Ti(2)
C(52)—O(5)—Ti(2)
C(62)—O(6)—Ti(2)
113.98(6)
114.45(6)
114.45(7)
76.41(6)
75.61(6)
75.79(6)
112.67(16)
112.62(16)
110.87(16)
107.11(11)
107.19(11)
105.92(11)
126.15(12)
125.98(12)
125.78(12)
O(2)—Ti—O(1)
O(2)—Ti—O(3)
O(1)—Ti—O(3)
O(2)—Ti—N
O(1)—Ti—N
O(3)—Ti—N
C(11)—N—C(31)
C(11)—N—C(21)
C(31)—N—C(21)
C(11)—N—Ti
C(31)—N—Ti
C(21)—N—Ti
C(12)—O(1)—Ti
C(22)—O(2)—Ti
C(32)—O(3)—Ti
114.03(9)
115.18(9)
113.92(10)
76.09(9)
75.78(8)
76.25(9)
112.0(2)
112.4(2)
112.5(2)
106.71(17)
106.15(17)
106.51(18)
126.98(17)
125.60(19)
125.18(18)
* Two independent molecules.

2836
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005
Zaitsev et al.
Table 3. Selected calculated bond lengths (d) and bond
angles (ω) in structures 3, 7, and 26
containing an unsubstituted Cp group at the titanium
atom have not been studied previously by Xꢀray difꢀ
fraction; however, according to known data,26—28 the
Ti—C bond lengths in related titanatranes containing
a Cp* group are similar to the values we found:
Parameter
3
7
26
Bond
Ti—N
Ti—O(1)
Ti—O(2)
Ti—O(3)
Ti—Cl
d/Å
2.416
1.905
1.905
1.906
—
2.40(1)—2.46(1)
and 2.416(6)—2.461(8)
(S,S,SꢀN(CH2CHMeO)3TiCp*)
(SꢀN(CH2CHMeO)ꢀ
2.486
1.895
1.897
1.895
—
2.430
1.847
1.847
1.847
2.270
—
—
—
—
—
Å
(CH2CH2O)2TiCp*). It was of interest to estimate the
influence of the additional Ti←N interaction in titanꢀ
atranes on the Ti—Cp bond parameters. Three compounds
of tetracoordinated titanium that contain a Cр group and
three Ti—O bonds have now been studied by Xꢀray difꢀ
Ti—C(1)
Ti—C(2)
Ti—C(3)
Ti—C(4)
Ti—C(5)
Angle
N—Ti—O(1)
N—Ti—O(2)
N—Ti—O(3)
N—Ti—Cl
2.453
2.456
2.447
2.462
2.454
2.450
2.447
2.452
2.440
2.451
ω/deg
74.8
74.8
74.8
—
fraction, namely, CpTi[O(2,6ꢀPri2C6H3)]3 (dTi—C
2.373—2.421 Å),32 CpTi(pꢀButꢀcalix[6]arene–3H)
(dTi—C
2.355—2.378 Å), and (CpTi)2(pꢀButꢀ
calix[6]arene–6H) (dTi—C 2.340—2.382 and
=
=
73.9
74.0
74.0
—
75.4
75.4
75.4
=
2.362—2.380 Å).33 Thus, an increase in the coordination
number of titanium results in a regular elongation of the
Ti—Cp bond located in the transꢀposition with respect to
nitrogen as an additional electron donor.
180.0
The Ti—O bond lengths in the studied compounds
(1.880(1)—1.898(1) and 1.881(1)—1.893(1) Å for the
two independent molecules in the crystal of 3 and
1.880(2)—1.886(2) Å for compound 12) are closely simiꢀ
lar to those found previously26,27 for various cycloꢀ
pentadienyltitanatranes (Cp*, C5Me4H, C5Me4Ph,
C5Me4Tol), namely, 1.856(7)—1.888(5) Å. Meanwhile,
the Ti—O bond lengths in molecules 3 and 12 markꢀ
edly exceed the values (1.824(2)—1.832(2) Å) found34
for a single monomeric titanium trialkoxide with a
Cp ring that was studied by Xꢀray diffraction,
namely, [η5ꢀC5H3(SiMe3)2]Ti(C6H9O3) (C6H9O3H3 is
1,3,5ꢀcisꢀhexanetriol).
In compounds 3 and 12, all the fiveꢀmembered rings
of the atrane skeleton incorporating the Ti←N bond have
an envelope conformation, the envelope "flaps" being
formed by the carbon atoms located in the αꢀpositions to
the N atom of the atrane moiety. Note that in the conforꢀ
mation found previously for nontransition metal atranes
with substituents in the βꢀpositions to nitrogen, the enveꢀ
lope "flaps" are formed by the methylꢀsubstituted ring
carbon atoms. The crystal of compound 3 contains only
the symmetrical diastereomer.
To elucidate the structural features of titanatranes, we
performed a quantum chemical (DFT/PBE) study of three
compounds, namely, cyclopentadienyltitanatranes 3 and 7
and 1ꢀchlorotitanatrane N(CH2CH2O)3TiCl (26). The
main calculated bond lengths and bond angles are sumꢀ
marized in Table 3. These values for compound 3 are
consistent with the values determined by Xꢀray crystalꢀ
lography. Comparison of the calculated bond lengths for
compounds 3 and 7 with the corresponding values for
compound 26 confirms the conclusion based on analysis
of Xꢀray diffraction data: the presence of an additional
titanium—nitrogen interaction markedly affects paramꢀ
eters of the Ti—O equatorial bonds but has little influence
on the Ti—X (axial substituent) bond length.
We studied the topological properties of the bonds
formed by titanium using the approach proposed by
Bader.35 The calculated electron densities (ρ(rb)), elecꢀ
tron density Laplacians (∇2ρ(rb)), and bond ellipticities (ε)
and the eigen values of the Hesse matrix of the electron
density function |λ1|/λ3 in the critical points of the Ti—N,
Ti—O, and Ti—Cl bonds (CP(3, –1) type of critical
points) are summarized in Table 4. The results obtained
imply an ionic character of the bonds studied ("closed
shell" interaction). Comparison of the resulting values
with the known values for silicon and germanium comꢀ
pounds attests to similarity of the topological properties
Table 4. Calculated values of the electron density (ρ(rb)), elecꢀ
2
tron density Laplacian (∇ ρ(rb)), bond ellipticity (ε), and |λ1|/λ3
in the critical points of the Ti←X bonds (X = N, O, Cl, type of
critical points CP(3, –1)) for compounds 3, 7, and 26
2
Comꢀ
pound
X
ρ(rb)
∇ ρ(rb)
ε
|λ1|/λ3
3
N
0.036
0.122
0.122
0.121
0.041
0.118
0.119
0.119
0.041
0.137
0.138
0.138
0.083
0.115
0.482
0.482
0.481
0.135
0.471
0.472
0.472
0.133
0.541
0.541
0.541
0.195
0.003
0.132
0.131
0.131
0.004
0.142
0.143
0.140
0.000
0.132
0.131
0.134
0.000
0.187
0.248
0.248
0.248
0.201
0.247
0.248
0.248
0.202
0.254
0.254
0.255
0.256
O(1)
O(2)
O(3)
N
O(1)
O(2)
O(3)
N
O(1)
O(2)
O(3)
Cl
7
26

Titanatranes substituted in the atrane framework
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005 2837
1
Asymmetrical titanatrane 3. H NMR, δ: 6.29 (s, 5 H, Cp);
of bonds (including transannular bonds) in titanatranes
and in silatranes or germatranes,36—38 despite the obvious
difference in the modes of formation of the transannular
bond in silatranes and titanatranes, which follows from
comparison of the geometric parameters of the molecules
(see above).
4.54—4.50 (m, 3 H, OCH); 2.67—2.57 (m, 6 H, NCH2); 1.21,
1.01, 0.99 (all d, 3 H each, Me, J = 6.3 Hz). No signals were
detected in the 13C NMR spectrum due to low concentration of
the sample.
MS, m/z (Irel (%)): 301 [M]+ (6), 257 [M – MeCHO]+ (84),
236 [M – Cp]+ (18), 213 [M – 2 MeCHO]+ (100), 192 [M –
Cp – MeCHO]+ (29), 158 [M – 2 MeCHO – C2H4 – HCN]+
(23), 129 [M – 2 MeCHO – C2H4 – HCN – CH2Me]+ (14),
113 [CpTi]+ (5).
Experimental
Reaction of complex 4 with triethanolamine (5). The syntheꢀ
sis was carried out similarly to the previous experiment starting
from complex 4 (1.05 g, 3.60 mmol), triethanolamine (5)
(0.54 g, 3.60 mmol), and triethylamine (1.10 g, 10.80 mmol).
The removal of the solvent gave a white powder (0.82 g);
All operations with organotitanium compounds were carried
out using standard Schlenk technique under argon. The solvents
were purified by known procedures immediately prior to use.
Tetrahydrofuran, dimethoxyethane (DME), and triethylamine
were kept over potassium hydroxide and then distilled over Na
benzophenone ketyl; toluene, benzene, mꢀxylene, nꢀhexane,
nꢀheptane, and nꢀoctane were kept over and then distilled from
sodium metal; chloroform and dichloromethane were treated
with concentrated sulfuric acid, washed with an aqueous soluꢀ
tion of potassium carbonate and water, dried by anhydrous calꢀ
cium chloride, and distilled from CaH2.
5
according to 1H NMR, this was a mixture of (Me3Siꢀη ꢀ
C5H4)Ti(OCH2CH2)3N (6) and CpTi(OCH2CH2)3N (7) in 7 : 3
1
ratio. Complex 6. H NMR, δ: 6.50 and 6.39 (both t, 2 H each,
Cp, J = 3.2 Hz); 4.27 (t, 6 H, OCH2, J = 4.8 Hz); 2.94 (t, 6 H,
NCH2, J = 4.8 Hz); 0.19 (s, 27 H, SiMe3). The 1H NMR signals
of compound 7 correspond to published data.12
1H and 13C NMR spectra were recorded in CDCl3 on a
Varian VXRꢀ400 spectrometer (400 and 100 MHz, respectively).
The residual protons of the deuterated solvents were used as the
internal standard; the chemical shifts are referred to Me4Si. The
mass spectra were recorded with direct sample injection and at
an ionizing voltage of 70 eV on a Varian CHꢀ7a mass spectromꢀ
eter (Phillips University, Magburg, Germany); the signals were
assigned using masses of the most abundant isotopes.
Reaction of complex 19 with triisopropanolamine (2). The
synthesis was carried out similarly to the previous experiment
starting from complex 19 (0.73 g, 2.71 mmol), compound 2
(0.52 g, 2.71 mmol), and triethylamine 0.82 g (8.13 mmol).
After removal of the solvent, the residue was washed with
nꢀhexane and filtered to give a white powder (0.60 g); according
to 1H NMR, this was chloro{[(1,1´,1″ꢀnitrilotris[2ꢀpropaꢀ
nolato])ꢀ(3)ꢀN,O,O´,O″]}titanium (20)23.
{[1ꢀ(2ꢀPhenylethanolato)ꢀ(1´,1´´ꢀnitrilobis[ethanolato])ꢀ
(3)ꢀN,O,O´,O´´]ꢀ[1,2,3,4,5ꢀη]cyclopentaꢀ2,4ꢀdienꢀ1ꢀyl}titaꢀ
nium (12). A solution of trialkanolamine 9 (1.23 g, 5.49 mmol)
in THF (15 mL) was added dropwise with stirring to a solution
of complex 8 (1.13 g, 5.49 mmol) in THF (20 mL). After 10 h,
the solvent was evaporated under reduced pressure and the resiꢀ
due was recrystallized from a dichloromethane—nꢀoctane mixꢀ
ture to give titanatrane 12 as a white powder (1.65 g, 90%).
1H NMR, δ: 7.36—7.21 (m, 5 H, Ph); 6.40 (s, 5 H, Cp); 5.61
(dd, 1 H, OCHPh, J = 10.4 Hz, J = 4.4 Hz); 4.54 and 4.43
(both td, 1 H each, OCH2, J = 11.8 Hz, J = 3.9 Hz); 4.20 and
4.13 (both dd, 1 H each, OCH2, J = 11.8 Hz, J = 6.1 Hz); 3.36
and 3.17 (both td, 1 H Hz, NCH2, J = 11.4 Hz, J = 6.2 Hz);
3.08 (dd, 1 H, NCH2, J = 12.2 Hz, J = 4.4 Hz); 2.91—2.85 (m,
2 H, NCH2); 2.73 (dd, 1 H, NCH2, J = 12.2 Hz, J = 3.7 Hz).
13C NMR, δ: 143.91, 128.33, 127.42, 125.16 (Ph); 116.92 (Cp);
82.36 (OCH); 70.79 (OCH2); 62.74, 56.34, 55.49 (all NCH2).
MS, m/z (Irel (%)): 335 [M]+ (3), 305 [M – CH2O]+ (2), 270
[M – Cp]+ (4), 229 [M – PhCHO]+ (100), 199 [M – PhCHO –
CH2O]+ (62), 164 [M – Cp – PhCHO]+ (12), 144 [M –
PhCHO – CH2O – C2H4 – HCN]+ (16), 129 [M – PhCHO –
CH2O – C2H4 – HCN – CH3]+ (15), 106 [M – Cp – PhCHO –
CH2O – C2H4]+ (7).
Commercial triethanolamine (5) and triisopropanolamine
(2) (Merck) were used.
5
Trichloro(η ꢀ2,4ꢀcyclopentadienꢀ1ꢀyl)titanium (1), triꢀ
chloro[(1,2,3,4,5ꢀη)ꢀ1ꢀ(trimethylsilyl)ꢀ2,4ꢀcyclopentadienꢀ1ꢀ
5
yl]titanium (4),39 trimethoxy(η ꢀ2,4ꢀcyclopentadienꢀ1ꢀ
yl)titanium (8),40 indenyltrichlorotitanium41 (19), fluorenylꢀ
triisopropoxytitanium (20),29 2ꢀ[bis(2ꢀhydroxyethyl)amino]ꢀ1ꢀ
phenylꢀ1ꢀethanol (9),42 2ꢀ[bis(2ꢀhydroxyethyl)amino]ꢀ1,2ꢀ
erythroꢀdiphenylꢀ1ꢀethanol (10), 2ꢀ[bis(2ꢀhydroxyethyl)amino]ꢀ
1,1ꢀdiphenylꢀ1ꢀethanol (11), and 2ꢀ[bis(2ꢀhydroxyethyl)amino]ꢀ
1,2ꢀthreoꢀdiphenylꢀ1ꢀethanol (15)* were prepared by known proꢀ
cedures.
{[(1,1´,1´´ꢀNitrilotris[2ꢀpropanolato])ꢀ(3)ꢀN,O,O´,O´´]ꢀ
[1,2,3,4,5ꢀη]cyclopentaꢀ2,4ꢀdienꢀ1ꢀyl}titanium (3). Triethylꢀ
amine (0.66 g, 6.57 mmol) was added to a solution of comꢀ
pound 2 (0.42 g, 2.19 mmol) in dichloromethane (15 mL). The
reaction mixture was cooled to –78 °C and then a solution of
complex 1 in dichloromethane (20 mL) was added dropwise
with stirring. After 12 h, the solvent was removed under reduced
pressure, anhydrous benzene (20 mL) was added, and the soluꢀ
tion was filtered. The precipitate was washed with benzene
(2×20 mL) on the filter and the solvent was evaporated. The
residue was recrystallized from toluene to give titanatrane 3 as a
white powder (0.53 g 80%), which represented a mixture of two
diastereomers in 4 : 1 ratio (symmetrical : asymmetrical).
{[(1R,2S/1S,2R)ꢀ[1,2ꢀDiphenylethanolato]ꢀ(1´,1´´ꢀnitriloꢀ
bis[ethanolato])ꢀ(3)ꢀN,O,O´,O´´]ꢀ[1,2,3,4,5ꢀη]cyclopentaꢀ2,4ꢀ
dienꢀ1ꢀyl}titanium (13). The synthesis was carried out similarly
to the previous experiment starting from complex 8 (1.2 g,
5.83 mmol) and ligand 10 (1.76 g, 5.83 mmol) to give titanatrane
1
Symmetrical titanatrane 3. H NMR, δ: 6.27 (s, 5 H, Cp);
4.68—4.61 (m, 3 H, OCH); 2.78—2.68 (m, 6 H, NCH2); 1.02
(d, 9 H, Me, J = 6.4 Hz). 13C NMR, δ: 116.43 (Cp); 76.21
(OCH); 62.68 (NCH2); 41.62 (Me).
1
13 as a white powder (2.32 g, 97%). H NMR, δ: 7.30—7.16,
6.98—6.90 (both m, 5 H each, Ph); 6.49 (s, 5 H, Cp); 5.66 (d,
1 H, OCHPh, J = 8.4 Hz); 4.75—4.68 (m, 2 H, NCHPh,
OCH(H)); 4.37—4.34 (m, 1 H, OCH(H)); 4.24—4.20,
* S. S. Karlov, A. A. Selina, A. V. Churakov, E. S. Chernyshova,
and G. S. Zaitseva, unpublished results.

2838
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005
Zaitsev et al.
4.03—3.99 (both m, 1 H each, OCH2); 3.49—3.43, 3.02—2.96,
2.82—2.78, 2.54—2.50 (all m, 1 H each, NCH2). 13C NMR, δ:
142.16, 133.13, 131.74, 128.62, 127.91, 127.30, 126.98 (Ph);
117.01 (Cp); 88.28 (OCH); 71.65, 71.20 (OCH2); 71.45 (NCH),
55.40, 54.35 (all NCH2).
Reaction of complex 8 with trialkanolamine 15. Ligand 15
(1.99 g, 6.60 mmol) was added in small portions, as the material
dissolved, over a period of 2 h to a stirred solution of complex 8
(1.36 g, 6.60 mmol) in THF (20 mL). After 4 days, the preꢀ
cipitated white solid was filtered off and recrystallized from
a dichloromethane—nꢀhexane mixture to give methoxyꢀ
{[(1R,2S/1S,2R)ꢀ[1,2ꢀdiphenylethanolato]ꢀ(1´,1″ꢀnitriloꢀ
bis[ethanolato])ꢀ(3)ꢀN,O,O´,O″]}titanium (17) as a white powꢀ
der (1.26 g, 51%). The mother liquor was concentrated and the
residue was recrystallized from a dichloromethane—nꢀoctane
mixture to give {[(1R,2R/1S,2S)ꢀ(1,2ꢀdiphenylethanolato)ꢀ
(1´,1″ꢀnitrilobis[ethanolato])ꢀ(3)ꢀN,O,O´,O″]ꢀ[1,2,3,4,5ꢀη]cyꢀ
clopentaꢀ2,4ꢀdienꢀ1ꢀyl}titanium (16) as a white powder
(0.82 g, 32%).
{[(1,1ꢀDiphenylethanolato)ꢀ(1´,1″ꢀnitrilobis[ethanolato])ꢀ
(3)ꢀN,O,O´,O″]ꢀ[1,2,3,4,5ꢀη]cyclopentaꢀ2,4ꢀdienꢀ1ꢀyl}titanium
(14). The synthesis was carried out similarly to the previous
experiment starting from complex 8 (0.66 g, 3.19 mmol) and
ligand 11 (0.96 g, 3.19 mmol). Recrystallization from a dichloroꢀ
methane—nꢀheptane mixture gave titanatrane 14 as a white powꢀ
der (0.87 g, 67%). 1H NMR, δ: 7.41—7.11 (m, 10 H, Ph);
6.51 (s, 5 H, Cp); 4.24—4.19, 4.16—4.10 (both m, 2 H each,
OCH2); 3.80 (s, 2 H, NCH2CPh2); 2.84—2.72 (m, 4 H,
NCH2). 13C NMR, δ: 148.04, 133.32, 128.30, 128.25,
126.48, 125.36, 124.96, 124.46 (Ph); 116.81 (Cp); 76.32
(CPh2); 70.76 (NCH2CPh2); 65.78 (OCH2); 57.34, 56.72
(both NCH2).
Complex 17. Found (%): C, 60.63; H, 6.36; N, 3.98;
Ti, 12.62. C19H23NO4Ti. Calculated (%): C, 60.49; H, 6.14;
1
N, 3.71; Ti, 12.69. H NMR, δ: 7.29—7.09 (m, 10 H, Ph); 6.12
(d, 1 H, OCHPh, J = 11.8 Hz); 5.02—4.95, 4.77—4.73 (both m,
1 H each, OCH(H)); 4.42—4.35 (m, 2 H, OCH2); 4.26 (s, 3 H,
OMe); 3.88—3.84 (m, 1 H, NCHPh); 3.45—3.43 (m, 1 H,
NCH(H)); 3.19—3.16 (m, 2 H, NCH2); 2.55—2.50 (m, 1 H,
NCH(H)). MS, m/z (Irel (%)): 377 [M]+ (10), 271 [M –
PhCHO]+ (100), 241 [M – PhCHO – CH2O]+ (32), 227 [M –
PhCHO – CH2CH2O]+ (40), 180 [M – PhCHO – PhCH2]+
(14), 64 [TiO]+ (17).
Reaction of complex 21 with triethanolamine (5). A solution
of triethanolamine (5) (0.19 g, 1.28 mmol) in THF (10 mL) was
added dropwise with stirring and cooling (–78 °C) to a solution
of complex 21 (0.50 g (1.28 mmol) in THF (10 mL). After 12 h,
the solvent was removed under reduced pressure, the resiꢀ
due was washed with nꢀhexane and filtered to give a white
powder (0.32 g); according to 1H NMR, this was (2ꢀpropaꢀ
nolato)ꢀ{[(2,2´,2″ꢀnitrilotris[ethanolato])ꢀ(3)ꢀN,O,O´,O″]}titaꢀ
Complex 16. 1H NMR, δ: 7.30—7.00 (m, 10 H, Ph); 6.44 (s,
5 H, Cp); 5.94 (d, 1 H, OCHPh, J = 9.9 Hz); 4.77, 4.50 (both td,
nium (22)12
.
Table 5. Crystal data and Xꢀray experiment and structure refinement details for compounds 3 and 12
Parameter
3
12
Molecular formula
Molecular mass
C15.75H25N1O3Ti1
324.27
C18H23Cl2N1O3Ti1
420.17
Crystal size/mm
System
Space group
0.15×0.10×0.05
Triclinic
P–1
0.10×0.05×0.05
Monoclinic
P21/n
a/Å
b/Å
c/Å
α/deg
8.7434(4)
8.7864(4)
23.4031(11)
95.737(1)
96.388(1)
113.946(1)
1611.97(13)
4
12.533(1)
9.5498(9)
16.819(2)
90
109.956(2)
90
1892.2(3)
4
1.475
β/deg
γ/deg
V/Å3
Z
dcalc/g cm–3
1.336
0.539
µ/mm–1
0.751
F(000)
690
872
Scan range over θ/deg
Ranges of reflection indexes
2.58—28.00
–11 < h < 11
–11 < k < 10
–30 < l < 30
12414
2.49—25.99
–14 < h < 15
–11 < k < 11
–20 < l < 20
11303
The number of measured reflections
The number of independent reflections (Rint
The number of refinement parameters
R1 (I < 2σ(I ))
)
7436 (0.0184)
581
3706 (0.0448)
317
0.0402
0.0491
wR2 (for all reflections)
Quality for F 2
0.1091
1.044
0.1297
1.029
Residual electron density
(max/min)/e Å–3
0.876/–0.348
1.665/–0.857

Titanatranes substituted in the atrane framework
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005 2839
1 H each, OCH2, J = 11.7 Hz, J = 3.7 Hz); 4.27—4.23 (m, 2 H,
OCH2); 3.96 (d, 1 H, NCHPh, J = 11.1 Hz); 3.66—3.59,
3.11—3.03 (both m, 1 H each, NCH2); 2.74, 2.43 (both dd,
1 H each, NCH2, J = 11.8 Hz, J = 3.5 Hz).
On longꢀterm keeping of a solution of compound 17 (diꢀ
chloromethane—nꢀheptane) in air, compound 18 precipitated
as a finely crystalline white solid poorly soluble in organic solꢀ
vents. The structure of compound 18 was determined by Xꢀray
diffraction analysis.
Reaction of complex 1 with compound 23. A solution of ligand
5 (0.51 g, 3.42 mmol) in DME (15 mL) was added dropwise to
sodium hydride (0.40 g, 10.61 mmol) in DME (20 mL). The
reaction mixture was refluxed for 6 h and then, with cooling to
–50 °C, a solution of compound 1 (0.75 g, 3.42 mmol) in DME
(20 mL) was added. After 15 h, the NaCl precipitate was filtered
off and washed with hot chloroform (3×30 mL). The solvent was
removed in vacuo and the residue was recrystallized from benꢀ
zene to give titanatrane 7 as a white powder (0.14 g, 16%). The
1H NMR signals of compound 7 agree with published data.12
Reaction of complex 4 with compound 24. A solution of BunLi
(5.30 mL) in nꢀhexane (1.98 mol L–1) was added to a solution of
compound 5 (0.50 g, 3.36 mmol) in DME (10 mL). The reacꢀ
tion mixture was stirred for 10 h and cooled to –50 °C, and a
solution of complex 4 (0.98 g, 3.36 mmol) in DME (10 mL) was
added dropwise. After 12 h, the precipitate was filtered off, and
the solvent was evaporated in vacuo. According to 1H NMR, the
reaction gave a product mixture difficult to identify.
of Young Ph.D´s, Grant MKꢀ3697.2004.3) and the Founꢀ
dation for the Support of Russian Science.
References
1. J. G. Verkade, Coord. Chem. Rev., 1994, 137, 233.
2. S. S. Karlov and G. S. Zaitseva, Khim. Geterotsikl. Soedin.,
2001, 1451 [Chem. Heterocycl. Compd., 2001, 37, 1325 (Engl.
Transl.)].
3. M. G. Voronkov, V. M. D´yakov, and S. V. Kirpichenko,
J. Organomet. Chem., 1982, 233, 1.
4. M. G. Voronkov and V. P. Baryshok, J. Organomet. Chem.,
1982, 239, 199.
5. A. Singh and R. C. Mehrotra, Coord. Chem. Rev., 2004,
248, 101.
6. J. G. Verkade, Acc. Chem. Res., 1993, 26, 483.
7. US Pat. 2935522; Chem. Abstrs, 1960, 54, 19491.
8. H. J. Cohen, J. Organomet. Chem., 1966, 5, 423.
9. H. J. Cohen, J. Organomet. Chem., 1967, 9, 177.
10. R. Taube and P. Knoth, Z. Anorg. Allg. Chem., 1990, 581, 89.
11. W. M. P. B. Menge and J. G. Verkade, Inorg. Chem., 1991,
30, 4628.
12. A. A. Naini, W. M. P. B. Menge, and J. G. Verkade, Inorg.
Chem., 1991, 30, 5009.
13. A. A. Naini, S. L. Ringrose, Y. Su, R. A. Jacobson, and J. G.
Verkade, Inorg. Chem., 1993, 32, 1290.
Reaction of complex 4 with compound 25. Compound 25
(1.31 g, 3.60 mmol) was added to a solution of complex 4 (1.05 g,
3.60 mmol) in mꢀxylene (20 mL). The reaction mixture was
refluxed for 20 h, and the solvent was evaporated in vacuo to give
14. M. K. Sharma, A. Singh, and R. C. Mehrotra, Ind. J. Chem.,
Sect. A, 2000, 39, 410.
15. R. L. Harlow, Acta Crystallogr., Sect. C, 1983, 39, 1344.
16. T. Kemmitt, N. I. AlꢀSalim, G. J. Gainsford, and
W. Henderson, Aust. J. Chem., 1999, 52, 915.
17. T. Kemmitt, N. I. AlꢀSalim, and G. J. Gainsford, Inorg.
Chem., 2000, 39, 6067.
5
the product (Me3Siꢀη ꢀC5H4)TiCl3•N(CH2CH2OSiMe3)3 as a
1
poorly soluble red powder (2.32 g). H NMR, δ: 6.88 and 6.57
(both t, 2 H each, Cp, J = 3.4 Hz); 4.05 (t, 6 H, OCH2, J =
5.1 Hz); 3.25 (t, 6 H, NCH2, J = 5.1 Hz); 0.09 (s, 27 H, Me).
Xꢀray diffraction study. The atrane crystals suitable for Xꢀray
crystallography were obtained on cooling to –30 °C of a solution
in toluene (for compound 3), a dichloromethane—nꢀoctane mixꢀ
ture (for compound 12), and a dichloromethane—nꢀheptane
mixture (for compound 18). The experimental reflection intenꢀ
sities were collected on a Bruker SMART automated diffractoꢀ
meter at 120.0(2) K using MoꢀKαꢀradiation (λ = 0.71073 Å,
graphite monochromator). The adsorption corrections were apꢀ
plied by measuring the intensities of equivalent reflections.43
The structures were solved by the direct method (SHELXꢀ8644).
All the nonhydrogen atoms were refined in the fullꢀmatrix anisoꢀ
tropic leastꢀsquares calculations for F2 (SHELXLꢀ9745). The
H atoms (except for the solvation toluene molecule in comꢀ
pound 3) were identified from the difference synthesis and reꢀ
fined isotropically. The H atoms in the solvation C7H8 molecule
disordered at the inversion center (compound 3) were placed
into calculated positions and refined using the riding model.
The crystal parameters, Xꢀray experiment and structure refineꢀ
ment details for compounds 3 and 12 are summarized in Table 5.
The atom coordinates are deposited with the Cambridge Strucꢀ
tural Database.
18. P. Sudhakar, C. V. Amburose, G. Sundararajan, and
M. Nethajt, Organometallics, 2004, 23, 4462.
19. Y. Kim and J. G. Verkade, Organometallics, 2002, 21, 2395.
20. Y. Kim, G. K. Jnaneshwara, and J. G. Verkade, Inorg. Chem.,
2003, 42, 1437.
21. F. Di Furia, G. Licini, G. Modena, R. Motterle, and W. A.
Nugent, J. Org. Chem., 1996, 61, 5175.
22. G. Boche, K. Mtsbus, K. Harms, and M. Marsch, J. Am.
Chem. Soc., 1996, 118, 2770.
23. W. A. Nugent and R. L. Harlow, J. Am. Chem. Soc., 1994,
116, 6142.
24. M. Bonchio, S. Calloni, F. Di Furia, G. Licini, G. Modena,
S. Moro, and W. A. Nugent, J. Am. Chem. Soc., 1997,
119, 6935.
25. M. Bonchio, G. Licini, G. Modena, S. Moro, O. Bortolini,
P. Traldi, and W. A. Nugent, Chem. Commun., 1997, 869.
26. Y. Kim, E. Hong, M. H. Lee, J. Kim, Y. Han, and Y. Do,
Organometallics, 1999, 18, 36.
27. Y. Kim, Y. Han, J.ꢀW. Hwang, M. W. Kim, and Y. Do,
Organometallics, 2002, 21, 1127.
28. Y. Kim and Y. Do, J. Organomet. Chem., 2002, 655, 186.
29. S. Y. Knjazhanski, G. Cadenas, M. Garcia, C. M. Perez,
I. E. Nifant'ev, I. A. Kashulin, P. V. Ivchenko, and K. A.
Lyssenko, Organometallics, 2002, 21, 3094.
30. S. Aldridge, R. J. Calder, D. L. Coombs, C. Jones, J. W.
Steed, S. Coles, and M. B. Hursthouse, New J. Chem., 2002,
26, 677.
The authors are grateful to J. A. C. Howard (UK) for
providing Xꢀray diffraction facilities.
This work was supported by the Council for Grants at
Russian Federation President (Program for State Support

2840
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 12, December, 2005
Zaitsev et al.
31. V. Pestunovich, S. Kirpichenko, and M. Voronkov, in The
Chemistry of Organic Silicon Compounds, Eds Z. Rappoport
and Y. Apeloig, Wiley, New York, 1998, Vol. 2, p. 1447.
32. A. V. Firth and D. W. Stephan, Inorg. Chem., 1998, 37, 4732.
33. A. J. Petrella, N. K. Roberts, D. C. Craig, C. L. Raston, and
R. N. Lamb, Chem. Commun., 2003, 1014.
40. A. N. Nesmeyanov, O. V. Nogina, N. A. Lazareva, and V. A.
Dubovitskii, Izv. Akad. Nauk SSSR, Ser. Khim., 1967,
808 [Bull. Acad. Sci. USSR, Div. Chem. Sci., 1967 (Engl.
Transl.)].
41. T. E. Ready, J. C. W. Chien, and M. D. Rausch,
J. Organomet. Chem., 1996, 519, 21.
34. D. M. Choquette, W. E. Buschmann, M. M. Olmstead, and
R. P. Planalp, Inorg. Chem., 1993, 32, 1062.
35. R. F. W. Bader, Atoms in Molecules—A Quantum Theory,
Oxford University Press, Oxford, 1990; R. F. W. Bader,
J. Phys. Chem., 1998, A102, 7314.
36. A. A. Korlyukov, K. A. Lyssenko, M. Yu. Antipin, V. N.
Kirin, E. A. Chernyshev, and S. P. Knyazev, Inorg. Chem.,
2002, 41, 5043.
37. J. M. Anglada, C. Bo, J. M. Bofill, R. Crehuet, and J. M.
Poblet, Organometallics, 1999, 18, 5584.
42. E. V. Gauchenova, S. S. Karlov, A. A. Selina, E. S.
Chernyshova, A. V. Churakov, J. A. K. Howard, N. A.
Troitsky, S. N. Tandura, J. Lorberth, and G. S. Zaitseva,
J. Organomet. Chem., 2003, 676, 8.
43. G. M. Sheldrick, SADABS, Program for Scaling and Correcꢀ
tion of Area Detector Data, University of Göttingen, Göttingen
(Germany), 1997.
44. G. M. Sheldrick, Acta. Crystallogr., 1990, A46, 467.
45. G. M. Sheldrick, SHELXLꢀ97, Program for the Refinement of
Crystal Structures, University of Göttingen, Göttingen (Gerꢀ
many), 1997.
38. E. V. Gauchenova, A. A. Selina, S. S. Karlov, E. Kh.
Yakubova, A. V. Churakov, J. A. K. Howard, D. A. Tyurin,
J. Lorberth, and G. S. Zaitseva, Z. Naturforsch., 2003,
58b, 1165.
39. A. M. Cardoso, R. J. H. Clark, and S. Moorhouse, J. Chem.
Soc., Dalton Trans., 1980, 1156.
Received June 24, 2005;
in revised form October 19, 2005