Diamine bis(phenolate) M(III) (Y, Ti) complexes: Synthesis, structures, and reactivity

Article abstract of DOI:10.1021/om9001389

Reactions of titanium and yttrium trichlorides with 1 equiv of the sodium or potassium salts of the diamine bis(phenolate) H₂ ^tBu2O₂NN′ (Me₂NCH₂CH ₂-(CH₂-2-HO-3,5-C₆H<

Full text of DOI:10.1021/om9001389

Organometallics 2009, 28, 3449–3458
3449
Diamine Bis(phenolate) M(III) (Y, Ti) Complexes: Synthesis,
Structures, and Reactivity
So´nia Barroso,† Jinlan Cui,‡ Jose´ Manuel Carretas,‡ Adelaide Cruz,‡ Isabel C. Santos,‡
M. Teresa Duarte,† Joa˜o P. Telo,† Noe´mia Marques,*,‡ and Ana M. Martins*,†
Centro de Qu´ımica Estrutural, Instituto Superior Te´cnico, AVenida RoVisco Pais, 1049-001 Lisboa, Portugal,
and Instituto Tecnolo´gico e Nuclear, 2686-953 SacaVe´m, Portugal
ReceiVed February 23, 2009
Reactions of titanium and yttrium trichlorides with 1 equiv of the sodium or potassium salts of the
t
diamine bis(phenolate) H2tBu2O2NN′ (Me2NCH2CH2-(CH2-2-HO-3,5-C6H2 Bu2)2) led to formation of
[TiCl(tBu2O2NN′)(L)] (L ) THF, 1; py, 2) and [YCl(tBu2O2NN′)(DME)], 3. Reactions of 1 or 3 with
MCH2-(2-NMe2)C6H4 and with M[2-(CH2NMe2)C6H4] (M ) Li, K) led to [Ti(tBu2O2NN′)(κ2-
(CH2C6H4NMe2))], 5, [Y(tBu2O2NN′)(κ2-(CH2C6H4NMe2))], 6, and [Y(tBu2O2NN′)(κ2-(C6H4CH2NMe2))],
7. [Y(tBu2O2NN′)N(SiMe3)2], 4, was obtained from 3 and KN(SiMe3)2, whereas [(Y(tBu2O2NN′)(CH2SiMe3))2(µ4-
O)(µ3-Li)2], 8, formed from reaction of 3 and LiCH2SiMe3. The reaction of 7 with 1 equiv of CH3CN
gave [Y(tBu2O2NN′)(NC(CH3)C6H4CH2NMe2)], 10, which displays a chelating ketimide ligand formed
by nitrile insertion in the Y-Ph bond. Further reaction with CH3CN led to [Y(tBu2O2NN′)(κ2-
(N(H)C(CH3)C(H)C(C6H4CH2NMe2)N(H)], 9, the formation of which involves an imine-enamine
tautomerism followed by a second nitrile insertion and 1,3-hydrogen shift. The reaction of 1 with CH3CN
gave [TiCl(tBu2O2NN′)(NCCH3)], which upon heating converts to a new paramagnetic species that is
likely a chloride-bridged Ti(III) dimer. The EPR study performed reveals that bis(phenolate) Ti(III)
complexes do not promote nitrile coupling reactions by electron transfer. The solid state molecular
structures of 1-9 revealed that in all the complexes the bis(phenolate) ligand is coordinated to the metal
center by the two oxygen atoms and the two nitrogen atoms with trans phenolate arrangement.
processes.15-17 Nevertheless, the studies reported so far did not
focus on the reactivity of paramagnetic diamine bis(phenolate)
species. The unique Ti(III) complex of this type described in
the literature is the zwitterionic complex [Ti(Me2NCH2CH2-
N(CH2-2-O-3-tBu-5-MeC6H2)2(OiPr)2 · Na(THF)2] obtained by
sodium amalgam reduction of the corresponding Ti(IV) bis(phe-
nolate) diamine.18 In view of the reactivity of Ti(III) species in
reductive coupling reactions19-22 and the role of redox-active
ligands, as amido phenolates and diimine, in “oxidative-
addition” reactions to Zr(IV) recently reported,23-26 we decided
to undertake a study of d1 Ti(III) complexes derived from
Introduction
In recent years group 3 and group 4 bis(phenolate) metal
complexes have deserved considerable interest due to their proper-
ties as catalysts of olefin and cyclic ester polymerization.1-10 These
studies have shown that the choice of phenolate ring substituents
and its combination with extra donor moieties incorporated in
the bis(phenolate) scaffolds are decisive for the stabilization of
active catalytic species.3,4,11-14 A large variety of ligands,
combining C-, N-, O-, S-, and P-based fragments with the
bis(phenolate) frame, have been prepared and made evident that
chelation has pronounced kinetic and thermodynamic conse-
quences that prevent dimerization and ligand redistribution
(11) Tshuva, E. Y.; Goldberg, I.; Kol, M.; Goldschmidt, Z. Organo-
metallics 2001, 20, 3017.
(12) Groysman, S.; Tshuva, E. Y.; Goldberg, I.; Kol, M.; Goldschmidt,
Z.; Shuster, M. Organometallics 2004, 23, 5291.
(13) Tshuva, E. Y.; Goldberg, I.; Kol, M. Inorg. Chem. 2001, 40, 4263.
(14) Ikpo, N.; Butt, S. M.; Collins, K. L.; Kerton, F. M. Organometallics
2009, 28, 837.
(15) Liang, L. C.; Chang, Y. N.; Lee, H. M. Inorg. Chem. 2007, 46,
2666.
(16) Kawaguchi, H.; Matsuo, T. J. Organomet. Chem. 2004, 689, 4228.
(17) Boyd, C. L.; Toupance, T.; Tyrell, B. R.; Ward, B. D.; Wilson, C.;
Cowley, A. R.; Mountford, P. Organometallics 2005, 24, 309.
(18) Sarazin, Y.; Howard, R. H.; Hughes, D. L.; Humphrey, S. M.;
Bochmann, M. Dalton Trans. 2006, 340.
* Corresponding authors. E-mail: ana.martins@ist.utl.pt.
† Instituto Superior Te´cnico.
‡ Instituto Tecnolo´gico e Nuclear.
(1) Amgoune, A.; Thomas, C. M.; Carpentier, J.-F. Macromol. Rapid
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Macromolecules 2003, 33, 3806.
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Spaniol, T. P.; Okuda, J. J. Am. Chem. Soc. 2003, 125, 4964.
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10.1021/om9001389 CCC: $40.75
2009 American Chemical Society
Publication on Web 05/04/2009

3450 Organometallics, Vol. 28, No. 12, 2009
Barroso et al.
Scheme 1
t
Me2NCH2CH2-(CH2-2-HO-3,5-C6H2 Bu2)2 and analogous d0
Y(III) complexes in order to compare their reactivity and assess
the potential of paramagnetic diamine bis(phenolate) complexes
in electron transfer processes.
compounds obtained. A comparable effect was noticed for the
phenolate substituents, whose bulkiness is critical to the
formation of mono- or binuclear complexes.13
Complexes 1 and 2 are the first neutral Ti(III) diamine
bis(phenolate) reported in the literature. The magnetic suscep-
tibility of 1 and 2 was determined at 25 °C as µeff ) 1.58 µB
and µeff ) 1.46 µB, respectively. These values correspond to
one unpaired electron per titanium, as expected for d1 metal
centers. The EPR spectra of 1 (toluene, 293 K) and 2 (hexane,
90 K) display symmetrical single lines with g ) 1.954 and g )
1.976, respectively, characteristic of Ti(III).
Results and Discussion
Chemical Studies. The reaction sequence used to prepare
all new compounds described in this work is presented in
Scheme 1. Treatment of TiCl3(THF)3 with 1 equiv of the sodium
derivative of the diamine bis(phenol) Me2NCH2CH2-(CH2-2-
HO-3,5-C6H2 Bu2)2 (H2tBu2O2NN′) in THF led to the synthesis
t
The room-temperature 1H NMR spectra of 3 show one set of
resonances for the diamine bis(phenolate) fragment, consistent
with a Cs symmetric (tBu2O2NN′) ligand environment, which is
not in accordance with the C1 symmetry found in the solid (vide
infra) and was indicative of fluxional behavior. In addition the
spectrum displays two resonances due to the protons of DME.
Variable-temperature studies have shown that on cooling a
solution of 3 in toluene-d8, decoalescence of the signals is
observed at about -50 °C and each diamine bis(phenolate)
ligand resonance splits into two in accordance with C1 sym-
metry. However, the low-temperature limiting spectrum could
not be reached since the resonances due to DME protons remain
broad even at -80 °C.
of [TiCl(tBu2O2NN′)(THF)], 1, in 83% yield. Addition of pyridine
to a THF solution of 1 results in an immediate color change
from orange to purple, indicative of THF replacement and the
quantitative formation of [TiCl(tBu2O2NN′)(py)], 2. Similarly,
YCl3(THF)2.5 reacts readily with 1 equiv of the potassium salt
of H2tBu2O2NN′ in DME at room temperature to yield the
corresponding diamine bis(phenolate)monochloride complex
[YCl(tBu2O2NN′)(DME)], 3, in high yield. Formation of the
monomeric yttrium complex 3 contrasts with the reported
synthesis of [Y(tBu2O2NNpy)(µ-Cl)(py)]2 · 3(C6H6),17 with a py-
ridyl substituent in the donor arm, and emphasizes the impor-
tance of the terminal amine bulk on the structure of the
The reaction of [YCl(tBu2O2NN′)(DME)] with 1 equiv of
KN(SiMe3)2 in THF proceeds readily and yields, after simple
workup, [Y(N(SiMe3)2)(tBu2O2NN′)], 4, which was obtained as
a white powder in moderate yield. As described for 3, the room-
(25) Blackmore, K. J.; Lal, N.; Ziller, J. W.; Heyduk, A. F. J. Am. Chem.
Soc. 2008, 130, 2728.
(26) Blackmore, K. J.; Ziller, J. W.; Heyduk, A. F. Inorg. Chem. 2005,
44, 5559.

Ti and Y Diamine Bis(phenolate)
Organometallics, Vol. 28, No. 12, 2009 3451
Scheme 2
temperature 1H NMR spectrum of 4 displays Cs symmetry. On
cooling a toluene-d8 solution of 4, all the resonances broaden
and at -30 °C the signal assigned to the protons of the NSiMe3
groups splits into two at 0.63 and 0.39 ppm. At -50 °C the
complexes27,28 and most likely results from the higher steric
bulk of octahedral coordination and the lower metal oxidation
state.
Chloride metathesis of 3 with LiCH2SiMe3 gave, upon
recrystallization from THF, the unusual complex Li2(µ4-O)-
t
resonances of the Bu groups and the aromatic ring protons
1
[Y(tBu2O2NN′)(CH2SiMe3)]2, 8. The H and 13C NMR spectra
resolve into a C1 symmetry pattern, but the remaining signals
are still poorly resolved.
t
of 8 reveal one set of resonances assigned to the Bu2O2NN′
Treatment of [TiCl(tBu2O2NN′)(THF)], 1, and [YCl(tBu2O2NN′)-
(DME)], 3, with 1 equiv of KCH2-(2-NMe2)C6H4 and LiCH2-
(2-NMe2)C6H4, respectively, led to [Ti(tBu2O2NN′)(κ2-CH2C6H4-
NMe2)], 5, obtained in 92% yield as a green microcrystalline
solid, and to [Y(tBu2O2NN′)(κ2-(CH2C6H4NMe2))], 6, isolated
in 78% yield as a yellow powder.
ligand and the CH2SiMe3, consistent with Cs symmetry. The
unequivocal identification of 8 was possible by X-ray diffraction
(see below), which shows an unusual µ4-O bridge between two
yttrium and two lithium centers. The origin of the oxygen bridge
is likely THF, as the maintenance of the trimethylsilyl methane
group in the yttrium coordination sphere rules out the possibility
of reaction with moisture. We tentatively suggest that the
formation of 8 may involve an ate-complex stabilized by
(Li(THF)n)+. Related complexes bearing oxygen and lithium
bridges have been reported for Sm and Y complexes.29-31
The effective magnetic moment of 5 at 22 °C was determined
as µeff ) 1.55 µB, in accordance with the values obtained for 1
1
and 2. The room-temperature H NMR spectrum of 6 shows
one set of resonances for the diamine bis(phenolate) fragment,
consistent with a Cs symmetric tBu2O2NN′ ligand environment.
On lowering the temperature, some of the resonances broadened
into the baseline, but a limiting spectrum could not be reached
in toluene.
The reaction of 7 with an excess of CH3CN gave [Y(tBu2O2-
NN′)(κ2-(N(H)C(CH3)C(H)C(C6H4CH2NMe2)N(H)], 9. The pro-
t
ton NMR spectrum of 9 features four resonances for the Bu
groups, four resonances for the aromatic phenoxide protons, four
resonances for the methylenic NCH2PhOH protons, four signals
for the diastereotopic methylenic protons of the NCH2CH2NMe2
chain, and two for the NMe2 groups. This pattern is consistent
with a rigid complex in solution with C1 symmetry. Furthermore,
the spectrum shows the expected resonances for the CH2C6H4-
NMe2 group and two additional resonances ascribed to the
protons of one methyl and one methine group. This spectrum
is consistent with the structure determined by X-ray diffraction
analysis (see below) that reveals the formation of a metallacyclic
ligand resulting from the insertion/coupling of two CH3CN
Reaction of [YCl(tBu2O2NN′)(DME)], 3, with 1 equiv of Li[2-
(CH2NMe2)C6H4] led to [Y(tBu2O2NN′)(κ2-(C6H4CH2NMe2))],
7. As for 6, the NMR spectrum of 7 features the required
resonances for the protons of the diamine bis(phenolate)
fragment consistent with a Cs symmetry and for the protons of
the C6H4CH2NMe2 ligand. A similar reaction between [TiCl-
(
tBu2O2NN′)(THF)], 1, and Li[2-(CH2NMe2)C6H4] was per-
formed, but the characterization of a defined species was not
possible. The addition of reagents caused a color change from
orange to greenish, indicative of the presence of a new Ti(III)
species, but all attempts to obtain good elemental analysis or
crystals for X-ray diffraction failed. The magnetic susceptibility
of the microcrystalline solid formed by cooling a hexane solution
of the crude (µeff (14 °C) ) 1.51 µB) and the EPR spectrum in
toluene (g ) 1.953) are compatible with the results obtained
for the other Ti(III) complexes described (1, 2, and 5). The high
instability of this product and, to a lesser extent, the instability
of 5 contrast with that of pentacoordinate bis(phenolate) Ti(IV)
(27) Gielens, E. E. C. G.; Dijkstra, T.; Berno, P.; Meetsma, A.; Hessen,
B.; Teuben, J. H. J. Organomet. Chem. 1999, 591, 88.
(28) Fokken, S.; Spaniol, T. P.; Kang, H. C.; Massa, W.; Okuda, J.
Organometallics 1996, 15, 5069.
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1988, 110, 1841.
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(31) Aspinall, H. C.; Tillotson, M. R. Inorg. Chem. 1996, 35, 2163.

3452 Organometallics, Vol. 28, No. 12, 2009
Barroso et al.
Figure 2. ORTEP diagram of [TiCl(tBu2O2NN′)(THF)], 1, with 40%
probability ellipsoids.
Figure 1. EPR spectra obtained during a period of time, upon
addition of CH3CN to 1.
molecules and the CH2C6H4NMe2 ligand. The reaction was
followed by proton NMR. Addition of 1 equiv of CH3CN to a
C6D6 solution of 7 showed the quantitative formation of a new
species that was identified as [Y(tBu2O2NN′)(NC(CH3)C6H4-
CH2NMe2)], 10, which contains a ketimide fragment formed
by acetonitrile insertion in the Y-C bond. Addition of a second
equivalent of CH3CN led to 9.
The formation of 9 may be envisaged as represented in
Scheme 2. The decisive reaction step is an imine-enamine
tautomerism that creates a nucleophilic methylene center through
a 1,3-hydrogen shift (i in Scheme 2). Subsequent intramolecular
nucleophilic attack on the nitrile carbon and a second γ-H shift,
commonly observed when the ketimide fragment is part of a
metallacycle, may thus lead to 9.32,33 Similar reactions have
been reported to take place in metal-sp3 carbon bonds of
zirconocene metallacycles and metal-sp2 bonds of scandium
metallocenes.32,34,35
The reaction of [Ti(tBu2O2NN′)(κ2-(CH2C6H4NMe2))], 5, with
acetonitrile proved unfruitful. A progressive color change from
greenish to red was observed upon CH3CN addition to a toluene
solution of 5; nevertheless, it was not possible to isolate any
compound resulting from nitrile insertion in the Ti-C bond or
resulting from an electron transfer process.22 The reaction of
[TiCl(tBu2O2NN′)(THF)], 1, with CH3CN was then performed
(Figure 1). In this case the nonexistence of a Ti-C bond
excludes the possibility of nitrile insertion, and it was possible
to follow the reaction by EPR.
A new Ti(III) species with g ) 1.962 forms upon addition
of the nitrile. This complex is likely [TiCl(tBu2O2NN′)(CH3CN)]
(1/CH3CN). The spectrum shows that at room temperature the
two compounds are present in solution and 1/CH3CN is the
major species. On heating at 70 °C another Ti(III) complex starts
to form with g ) 1.957. On prolonged heating, either 1 or
1/CH3CN is completely converted into the third compound,
which is the thermodynamic product and confirms that electron
transfer from the titanium to the ligands does not take place.
Attempts to characterize this compound have not yet been
productive, but we tentatively assign this result to the formation
Figure 3. ORTEP diagram of [TiCl(tBu2O2NN′)(py)], 2, with 40%
probability ellipsoids.
of a chlorine-bridged Ti(III) dimer that might form upon
dissociation of CH3CN and, possibly, NMe2 dissociation favored
by heating. The dimerization would thus result from the
coordinative insaturation of the transient tetracoordinated Ti
center. We are currently working to test this hypothesis.
Crystallographic Studies. The molecular structures of
complexes 1-9 were determined by single-crystal X-ray dif-
fraction analysis.
Crystals of 1 were obtained from hexane at -20 °C with
two molecules and one cocrystallized hexane molecule in the
unit cell. Crystals of 2 and 5 were obtained from toluene and
hexane, respectively. The crystals of 5 were small and had poor
diffracting power, so that the diffraction data obtained have low
quality. Even so, the structure was unequivocally determined
and the data are in agreement with those obtained for the other
Ti(III) complexes reported. ORTEP drawings of 1, 2, and 5 are
shown in Figures 2-4, respectively. Relevant bond lengths and
angles are displayed in Table 1. In all complexes the metal
coordination geometry is best described as distorted octahedral.
The equatorial plane is defined by O(1), O(2), and N(2) of the
bis(phenolate) ligand and the neutral ligand (THF, 1, py, 2,
NMe2, 5). The axial positions are occupied by the tripodal
nitrogen N(1) and Cl(1) in 1 and 2 and C(71) in 5. All
compounds have in common trans-phenolate moieties. In 1 and
2 the titanium atom is slightly away from the equatorial mean
square plane (0.1622(19) and 0.1580(13) Å, respectively), while
in 5 it is perfectly within the plane (0.0752(24) Å). The Ti-O
distances in complexes 1, 2, and 5 are within the range usually
found and comparable to others reported for octahedral diamine
(32) Bercaw, J. E.; Davies, D. L.; Wolczanski, P. T. Organometallics
1986, 5, 450.
(33) Doxsee, K. M.; Farahi, J. B.; Hope, H. J. Am. Chem. Soc. 1991,
113, 8889.
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Organometallics 2008, 27, 6096.
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Ti and Y Diamine Bis(phenolate)
Organometallics, Vol. 28, No. 12, 2009 3453
Figure 4. ORTEP diagram of [Ti(tBu2O2NN′)(κ2-CH2C6H4NMe2)],
5, with 40% probability ellipsoids.
Table 1. Selected Bond Lengths [Å] and Angles (deg) for 1, 2, and 5
1
2
5
Figure 5. ORTEP diagram of [YCl(tBu2O2NN′)(DME)] · 0.5(O2C4-
H10) (3 · 0.5(O2C4H10)), with 40% probability ellipsoids.
Ti(1)-O(2)
1.906(3)
1.905(3)
2.277(4)
2.281(4)
2.4182(15)
2.225(3)
1.898(2)
1.904(2)
2.259(3)
2.296(2)
2.4166(11)
1.894(4)
1.924(4)
2.386(5)
2.312(5)
Ti(1)-O(1)
Ti(1)-N(1)
Ti(1)-N(2)
Ti(1)-Cl(1)
Ti(1)-O(3)
Ti(1)-C(71)
2.276(5)
2.315(6)
163.04(17)
Ti(1)-N(3)
2.245(3)
166.25(9)
169.31(7)
O(1)-Ti(1)-O(2)
N(1)-Ti(1)-Cl(1)
N(3)-Ti(1)-N(1)
C(71)-Ti(1)-N(1)
N(3)-Ti(1)-N(2)
O(3)-Ti(1)-N(2)
167.54(14)
173.95(10)
110.38(18)
170.84(18)
173.86(18)
173.49(10)
172.23(15)
bis(phenolate) complexes.13,17,18,36,37 The Ti-N distances found
in complexes 1 and 2 are in the upper range of Ti-Namine bond
lengths typically found in neutral Ti(III) complexes (1.857-2.285
Å),38-40 although they are shorter than in the anionic Ti(III)
diamine bis(phenolate) complex [Ti(Me2NCH2CH2N(CH2-2-O-3-
tBu-5-MeC6H2)2(OiPr)2 · Na(THF)2]18 (d(Ti-N) 2.357 Å) and in
Ti(III) trisamidotriazacycloundecane [Ti(N(Ph)SiMe2)3-tacu], which
displays Ti-N bond lengths as long as 2.425 Å.41 In 5, those
distances are clearly longer than in 1 and 2. The lengthening of
the Ti-N(1) bond, in particular, is noticeable due to the trans effect
produced by the alkyl moiety of the CH2PhNMe2.
Complex 3 crystallized from a DME solution with two
crystallographically independent molecules (3a, 3b) in the unit
cell and one DME molecule in the lattice. Colorless crystals of
4 were grown from a toluene/hexane mixture. ORTEP diagrams
for 3a and 4 are shown in Figures 5 and 6, respectively and
selected bond lengths and angles are given in Table 2.
Figure 6. ORTEP diagram of [Y(N(SiMe3)2)(tBu2O2NN′)], 4, with
40% probability ellipsoids.
distorted due to the constrained nature of the κ4-O2NN′ ligand,
can be described as a capped octahedron. In molecule 3a the
atoms O(1), N(1), and N(2) occupy one triangular face, while
O(2), Cl(1), and O(10) form a staggered triangular face on the
other side of the central yttrium atom and O(11) is capping
the latter face of the octahedron. In 3b the coordination
polyhedron is defined by O(3), N(3), N(4) and O(4), Cl(2),
O(21), with O(20) in the capping position. Compound 4 adopts
a distorted trigonal-bipyramidal geometry, with N(1) and N(3)
occupying the axial sites (N(1)-Y-N(3) angle of 154.73(15)°).
The average Y-O distances to the phenoxide ligand in 3a and
in 3b are slightly longer than the corresponding distance in 4,
as expected for a compound with a higher coordination number.
The Y-N(1) and Y-N(2) distances in 3a and the Y-N(3) and
Y-N(4) in 3b are similar to the corresponding distances in 4.
The two TMS groups in the amide ligand of 4 are inequivalent
(the Y-N(3)-Si(1) angle is more acute than the Y-N(3)-Si(2)
angle by 14.3°) and in accordance with the corresponding
The seven-coordinate yttrium center in 3 is surrounded by
two oxygen atoms and two nitrogen atoms from the diamine
bis(phenolate) ligand, one chlorine atom, and two oxygen atoms
of the DME molecule. The coordination geometry, which is
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(39) Bodner, A.; Jeske, P.; Weyhermuller, T.; Wieghardt, K.; Dubler,
E.; Schmalle, H.; Nuber, B. Inorg. Chem. 1992, 31, 3737.
(40) Dias, A. R.; Martins, A. M.; Ascenso, J. R.; Ferreira, H.; Duarte,
M. T.; Henriques, R. T. Inorg. Chem. 2003, 42, 2675.
1
resonances in the low-temperature H NMR separated by 0.24
ppm. The Y-O and Y-N distances found in 3 and 4 compare
with those reported for [Y(tBu2O2NO)(CH2SiMe3)(THF)],42
(41) Martins, A. M.; Ascenso, J. R.; de Azevedo, C. G.; Dias, A. R.;
Duarte, M. T.; Ferreira, H.; Ferreira, M. J.; Henriques, R. T.; Lemos, M. A.;
Li, L.; da Silva, J. F. Eur. J. Inorg. Chem. 2005, 1689.
(42) Cai, C.-X.; Toupet, L.; Lehmann, W.; Carpentier, J.-F. J. Orga-
nomet. Chem. 2003, 683, 131.

3454 Organometallics, Vol. 28, No. 12, 2009
Barroso et al.
Table 2. Selected Bond Lengths [Å] and Angles (deg) for
3 · 0.5(O2C4H10) and 4
3b
3a
4
Y(2)-O(3)
Y(2)-O(4)
Y(2)-O(21)
Y(2)-O(20)
Y(2)-Cl(2)
Y(2)-N(3)
Y(2)-N(4)
2.137(7)
2.188(8)
2.455(9)
2.622(8)
2.618(4)
2.579(9)
Y(1)-O(1)
Y(1)-O(2)
Y(1)-O(10)
Y(1)-O(11)
Y(1)-Cl(1)
Y(1)-N(1)
2.156(8)
2.166(7)
2.501(8)
2.610(9)
2.611(3)
2.557(9)
2.120(4)
2.134(4)
2.534(4)
2.617(12) Y(1)-N(2)
Y(1)-N(3)
2.620(12) 2.583(5)
2.325(5)
N(1)-Y(1)-N(3)
154.73(15)
91.07(16)
N(2)-Y(1)-N(3)
O(1)-Y(1)-O(2)
O(1)-Y(1)-N(1)
O(1)-Y(1)-N(2)
O(2)-Y(1)-N(1)
O(2)-Y(1)-N(2)
N(1)-Y(1)-N(2)
O(3)-Y(2)-O(4)
O(3)-Y(2)-N(3)
O(3)-Y(2)-N(4)
O(4)-Y(2)-N(3)
O(4)-Y(2)-N(4)
N(3)-Y(2)-N(4)
153.7(3)
75.9(3)
92.7(4)
79.9(3)
88.1(4)
68.6(3)
152.6(3)
77.6(3)
92.2(3)
76.4(3)
86.8(3)
69.4(3)
104.27(17)
81.34(14)
98.19(15)
77.56(14)
136.77(14)
69.85(15)
O(3)-Y(2)-O(21) 79.4(3)
O(4)-Y(2)-O(21) 87.3(3)
Figure 8. ORTEP diagram of [YtBu2O2NN′)(C6H4CH2NMe2)], 7,
with 40% probability ellipsoids.
O(3)-Y(2)-Cl(2)
O(4)-Y(2)-Cl(2)
N(3)-Y(2)-Cl(2)
N(4)-Y(2)-Cl(2)
94.3(2)
111.7(3)
145.8(3)
79.4(3)
O(21)-Y(2)-Cl(2) 128.7(2)
O(21)-Y(2)-N(3) 82.4(3)
O(21)-Y(2)-N(4) 150.9(3)
O(10)-Y(1)-Cl(1) 127.7(2)
O(10)-Y(1)-N(1) 82.7(3)
O(10)-Y(1)-N(2) 151.9(3)
O(1)-Y(1)-N(3)
Table 3. Selected Bond Lengths [Å] and Angles (deg) for 6 · (C7H8)
and 7
6 · C7H8
7
118.85(16)
108.90(15)
O(2)-Y(1)-N(3)
Y(1)-O(1)
2.139(18)
2.1585(19)
2.563(2)
2.523(2)
2.518(2)
2.439(3)
Y(1)-O(1)
2.1430(19)
2.1586(18)
2.568(2)
2.538(2)
2.503(2)
Y(1)-O(2)
Y(1)-O(2)
[Y(tBu2O2NO)(N(SiHMe2)2)(THF)], [Y(tBu2O2NNpy)(µ-Cl)(py)]2 ·
3(C6H6),17 and [Y(adam,MeO2NO)(N(SiHMe2)2)].7,26,42 The Y-Cl
and Y-O(DME) are in the ranges where these distances are
found in yttrium complexes.43-45
Crystals of 6 · C7H8 and 7 were grown from toluene
solutions. Both complexes are six-coordinate by the oxygen
and nitrogen atoms of the tBu2O2NN′ ligand and by the carbon
and nitrogen atoms of the hydrocarbyl ligand. The coordina-
tion geometry in both complexes is best described as distorted
octahedral. ORTEP drawings of 6 and 7 are shown in Figures
7 and 8, respectively, and relevant bond lengths and angles
are shown in Table 3.
The average Y-O distances of 2.1489(19) and 2.1508(19)
Å to the phenoxide ligand in 6 and 7, respectively, are similar
and are in the range found for 3 and 4. The Y-N(1) and
Y-N(2) distances (2.5683(2) and 2.523(2) Å, respectively)
in 6 compare with the corresponding distances (2.568(2) and
2.538(2) Å) in 7. The Y-C and Y-N distances to the
bidentate hydrocarbyl ligand are similar in both complexes
Y(1)-N(1)
Y(1)-N(1)
Y(1)-N(2)
Y(1)-N(2)
Y(1)-N(3)
Y(1)-N(3)
Y(1)-C(30)
Y(1)-C(30)
Y(1)-C(37)
Y(1)-C(37)
2.482(3)
90.84(7)
84.94(7)
147.73(8)
77.80(7)
101.21(8)
79.67(7)
92.30(7)
102.97(9)
105.93(8)
160.63(9)
91.19(9)
160.97(8)
O(1)-Y(1)-N(3)
O(2)-Y(1)-N(3)
O(1)-Y(1)-O(2)
O(1)-Y(1)-N(1)
O(1)-Y(1)-N(2)
O(2)-Y(1)-N(1)
O(2)-Y(1)-N(2)
O(1)-Y-C(30)
O(2)-Y-C(30)
N(1)-Y-C(30)
N(2)-Y-C(30)
N(2)-Y-N(3)
90.45(7)
87.77(7)
146.48(8)
77.37(7)
102.60(7)
80.20(7)
92.31(8)
105.99(9)
104.59(9)
156.22(9)
87.02(9)
155.43(8)
O(1)-Y(1)-(3)
O(2)-Y(1)-(3)
O(1)-Y(1)-(2)
O(1)-Y(1)-(1)
O(1)-Y(1)-(2)
O(2)-Y(1)-(1)
O(2)-Y(1)-(2)
O(1)-Y-C(37)
O(2)-Y-C(37)
N(1)-Y-C(37)
N(2)-Y-C(37)
N(2)-Y-N(3)
(2.439(3) and 2.518(2) Å in 6 and 2.482(3) and 2.503(2) Å
in 7) and are in the range found for other yttrium hydrocarbyl
complexes.46,47
The structure of Li2(µ4-O)[Y(tBu2O2NN′)(CH2SiMe3)]2 (Figure
9, Table 4) has a square-like Y2Li2 array linked by four oxygen
atoms of the (tBu2O2NN′) ligands with a µ4-O ligand lying in
the middle of the Y2Li2 plane. The coordination sphere of the
yttrium atoms is completed by the two nitrogen atoms of the
tBu2O2NN′ ligand and the carbon atom of the alkyl ligand and
displays distorted octahedral geometry.
The Y-O, Y-N, and Y-C distances are similar to the
corresponding distances in the complexes mentioned above
and compare with those found in yttrium complexes reported
in the literature.7,17,46,47 The Li-O distances are in the range
usually found between Li+ cations and neutral oxygen donor
(43) Wang, J.; Sun, H.; Yao, Y.; Zhang, Y.; Shen, Q. Polyhedron 2008,
27, 1977.
(44) Williams, C. E.; Sinenkov, M. A.; Fukin, G. K.; Sheridan, K.;
Lynam, J. M.; Trifonov, A. A.; Kerton, F. M. Dalton Trans. 2008, 3592.
(45) Arndt, S.; Trifonov, A. A.; Spaniol, T. P.; Okuda, J.; Kitamura,
M.; Takahashi, T. J. Organomet. Chem. 2002, 647, 158.
(46) Marinescu, S. C.; Agapie, T.; Day, M. W.; Bercaw, J. E.
Organometallics 2007, 26, 1178.
Figure 7. ORTEP diagram of [YtBu2O2NN′)(CH2C6H4NMe2)](C7H8)
(6 · C7H8), with 40% probability ellipsoids.

Ti and Y Diamine Bis(phenolate)
Organometallics, Vol. 28, No. 12, 2009 3455
Figure 9. ORTEP diagram of [(Y(tBu2O2NN′)(CH2SiMe3))2(µ-O)-
(µ-Li)2], 8, with 40% probability ellipsoids.
Figure10. ORTEPdiagramof[Y(tBu2O2NN′)(κ2-N(H)C(CH3)C(H)C-
(C6H4CH2NMe2)N(H))], 9, with 40% probability ellipsoids.
Table 4. Selected Bond Lengths [Å] and Angles (deg) for 8 and 9
8
9
typical of single and double bonds, thus reflecting the charge
delocalization between all atoms.
Y(1)-O(1)
Y(1)-O(2)
Y(1)-O(3)
Y(1)-N(1)
Y(1)-N(2)
2.210(3)
2.250(3)
2.1613(6)
2.544(4)
2.596(4)
Y(1)-O(1)
Y(1)-O(2)
Y(1)-N(1)
Y(1)-N(2)
Y(1)-N(3)
Y(1)-N(4)
N(3)-C(30)
C(30)-C(31)
C(31)-C(32)
N(4)-C(32)
2.147(2)
2.110(2)
2.595(3)
2.552(3)
2.306(3)
2.377(3)
1.321(5)
1.398(5)
1.392(5)
1.329(5)
Experimental Section
General Procedures. All preparations and subsequent manipula-
tions were carried out using standard Schlenk line and drybox
techniques in an atmosphere of dinitrogen. THF, toluene, pentane,
1,2-dimethoxyethane, and n-hexane were dried by standard methods
and degassed prior to use. Toluene-d8 and benzene-d6 were dried
over Na and distilled. 2,4-Di-tert-butylphenol was sublimed prior
to use. The bis(phenolate) ligand was prepared by literature
procedures.48
Y(1)-Li(1)
Y(1)-Li(1)#1
Y(1)-C(31)
90.45(7)
87.77(7)
146.48(8)
O(1)-Y(1)-O(3)
O(2)-Y(1)-O(3)
O(1)-Y(1)-O(2)
O(1)-Y(1)-N(1)
O(1)-Y(1)-N(2)
O(2)-Y(1)-N(1)
O(2)-Y(1)-N(2)
O(1)-Y-C(31)
O(3)-Y(1)-N(2)
N(2)-Y-N(3)
81.99(8)
82.23(8)
154.42(11)
78.85(10)
90.80(11)
81.39(11)
97.36(11)
93.32(14)
160.15(8)
155.43(8)
162.06(14)
156.22(9)
87.02(9)
O(1)-Y(1)-O(2)
115.79(9)
75.84(9)
94.40(10)
77.17(9)
127.84(10)
146.64(9)
152.24(10)
160.97(8)
49
50
TiCl3(THF)3 and YCl3(THF)2.5 were prepared as described
in the literature. Nuclear magnetic resonance (NMR) spectra were
1
O(1)-Y(1)-N(4)
N(1)-Y-N(3)
recorded on a Varian 300 MHz spectrometer. H and 13C NMR
spectra were referenced internally to residual protio-solvent (1H)
or solvent (13C) resonances and reported relative to tetramethylsilane
(δ 0). The assessment of proton and carbon resonances has been
based on COSY and HSQC experiments. EPR experiments were
run in a Bruker EMX EPR spectrometer and calibrated using
Perilene+•/H2SO4 as internal standard. The magnetic susceptibility
was determined from powder samples of the compounds using a
Sherwood Scientific magnetic susceptibility balance based on
Evans’ method. Diamagnetic corrections for the diamino-bis(phe-
nolate) ligand were applied. Carbon, hydrogen, and nitrogen
analyses were performed in-house using an EA110 CE Instruments
automatic analyzer.
C(31)-Y(1)-N(1)
N(1)-Y-C(30)
N(2)-Y-C(30)
ligands. The [(Y(tBu2O2NN′)(CH2SiMe3)2(O)] moiety is
thus best formulated as an ate-Y dimer with a bridging oxo
ligand.
Diffraction-quality crystals of 9 were obtained by slow
evaporation of a hexane solution. The coordination geometry
can be described as a distorted octahedron, with the atoms O(1),
N(2), and N(3) occupying one triangular face and O(2), N(1),
and N(4) forming a staggered triangular face on the other side
of the central yttrium atom (Figure 10). Relevant bond lengths
and angles are shown in Table 4.
The average Y-O bond distance of 2.128(2) Å and the Y-N
distances of 2.306(3) and 2.377(3) Å to the phenoxide ligand
are in the range found for other bis(phenoxide) yttrium
complexes.7,17,47 The bidentate [N(H)C(CH3)C(H)C(C6H4-
CH2NMe2)N(H)] ligand is symmetrically coordinated to yttrium,
as shown by the bond distances Y-N(3) and Y-N(4) (2.306(3)
and 2.377(3) Å´, respectively) and the Y-N(3)-C(30) and
Y-N(4)-C(32) angles of 132.8(3)° and 130.1(3)°, respectively.
In the heterocycle the bond distances N(3)-C(30), C(30)-C(31),
C(31)-C(32), and N(4)-C(32) are within the range of values
[TiCl(tBu2O2NN′)(THF)] (1). A solution of H2(tBu2O2NN′) (1.05
g, 2.00 mmol) in THF was added to a suspension of NaH (0.11
g, 4.40 mmol) in the same solvent at -30 °C. The temperature
was allowed to rise slowly to room temperature and further
stirred for 2 h. The colorless solution of Na2(tBu2O2NN′) obtained
was filtered through Celite and added to a suspension of
TiCl3(THF)3 (0.74 g, 2.00 mmol) in THF at -80 °C. The mixture
was strirred for 4 h and allowed to reach room temperature
slowly. The orange solution obtained was evaporated to dryness,
and the residue was extracted in Et2O and filtered. Evaporation
of the solution to dryness led to a microcrystalline orange solid
in 83% yield (1.13 g, 1.67 mmol). Crystals suitable for X-ray
(48) Tshuva, E. Y.; Versano, M.; Goldberg, I.; Kol, M.; Weitman, M.;
Goldschmidt, Z. Inorg. Chem. Commun. 1999, 2, 371.
(49) Manzer, L. E. Inorg. Synth. 1982, 21, 135.
(50) Hermann, W. A. Synth. Methods Organomet. Inorg. Chem. 1997,
6, 34.
(47) Cai, C.-X.; Toupet, L.; Lhemann, C. W.; Carpentier, J.-F. J.
Organomet. Chem. 2003, 683, 131.

3456 Organometallics, Vol. 28, No. 12, 2009
Barroso et al.
Table 5. Crystallographic Data for 1, 2, and 5
diffraction were obtained from hexane at -20 °C. µeff(20 °C) )
1.46 µB. Anal. Calcd for C42H72N2O4Cl: C 67.05; H 9.64; N
3.72. Found: C 67.05; H 10.40; N 3.91.
1
2
5
empirical formula
2(C38H62ClN2O3Ti) · C39H59ClN3O2Ti C43H66N3O2Ti
[TiCl(tBu2O2NN′)(py)] (2). The initial procedure described for
1 was used to prepare 2. After addition of TiCl3(THF)3, pyridine
(0.40 mL, 5 mmol) was added to the reaction mixture. The
temperature was allowed to attain room temperature and a pur-
ple solution formed. The solvent was evaporated to dryness and
the residue was extracted in Et2O, filtered, and evaporated to
dryness, leading to a purple crystalline solid in 89% yield (1.22 g,
1.78 mmol). Crystals suitable for X-ray diffraction were obtained
from toluene at -20 °C. EPR (3 × 10-3 M in hexane, 90 K): g )
1.976. µeff(20 °C) ) 1.58 µB. Anal. Calcd for C39ClH59N3O2Ti: C,
67.21; H, 8.99; N, 6.35. Found: C, 67.09; H, 9.27; N, 6.06.
[Y(tBu2O2NN′)Cl(DME)] (3). Addition of a solution of K2-
3(C4H10O)
fw
1578.85
150(2)
685.24
150(2)
monoclinic
P21/c
704.89
150(2)
triclinic
temp (K)
cryst syst
space group
a (Å)
b (Å)
c (Å)
R (deg)
ꢀ (deg)
γ (deg)
V (Å3)
triclinic
j
j
P1
P1
9.7830(12)
17.268(2)
27.901(4)
94.657(4)
90.273(5)
90.228(4)
4697.7(11)
2, 1.116
16.634(7)
17.251(6)
15.664(4)
90
117.842(17)
90
3975(2)
4, 1.145
0.317
10.046(4)
11.641(5)
18.246(8)
99.007(17)
90.674(18)
104.869(18)
2033.9(15)
2, 1.151
Z, Dcalc (g cm-3
)
µ(mm-1
reflns measd
)
0.279
49 190
0.248
27 411
28 518
(
tBu2O2NN′) (2.89 g, 4.81 mmol) in 1,2-dimethoxyethane (DME)
unique reflns [R(int)] 17 155 [0.0499]
obsd reflns [I > 2σ(I)] 11 407
7246 [0.1285]
3530
0.0538
6986 [0.1667]
3392
0.0965
to a solution of YCl3(THF)2.5 (1.81 g, 4.81 mmol) in the same
solvent at room temperature resulted, after stirring overnight, in a
white suspension. After separation of the potassium chloride, the
solvent was removed under vacuum, giving a white solid, which
was further washed with hexane. Yield: 80% (2.84 g, 3.85 mmol).
X-ray quality crystals of 3 were grown by slow concentration of a
R1
wR2
0.0894
0.2496
0.1198
0.2879
9H, 9H, N(Si(CH3)3)2). 13C(1H) NMR (δ, ppm, C6D6): 160.7 (2-
t
t
t
C6H2 Bu2), 137.7 (5-C6H2 Bu2), 136.3 (3-C6H2 Bu2), 125.8 (6-C6H2-
tBu2), 124.4 (4-C6H2 Bu2), 124.0 (1-C6H2 Bu2), 61.6 (NCH2Ph)),
58.1 (NCH2CH2NMe2), 51.8 (NCH2CH2NMe2), 47.7 (N(CH3)2),
35.5 (3-C6H2(CMe3)2), 34.2 (5-C6H2(CMe3)2), 32.1 (5-C6H2(CMe3)2),
30.7 (3-C6H2(CMe3)2), 6.0 (s, Si(CH3)3). Anal. Calcd for C40H72-
N3O2Si2Y: C, 62.22, H, 9.40, N, 5.44. Found: C, 62.21, H, 9.37,
N, 5.20.
t
t
1
DME solution. H NMR (δ, ppm, C6D6): 7.67 (2H, d, JHH ) 2.4
t
t
Hz, 4-C6H2 Bu2), 7.15 (d, 2H, d, JHH ) 2.4 Hz, 6-C6H2 Bu2), 4.08
(d, 2H, JHH ) 12.6 Hz, NCH2Ph), 3.29 (4H, NCH2CH2N(CH3)2 +
4H, CH3OCH2CH2OCH3), 3.18 (s, 6H, CH3OCH2CH2OCH3), 2.91
(d, 2H, JHH ) 12.6 Hz, NCH2Ph), 2.02 (s, 6H, N(CH3)2), 1.77 (s,
t
t
1
18H, 3-C6H2 Bu2), 1.45 (s, 18H, 5-C6H2 Bu2). H NMR (δ, ppm,
tol-d8): 7.61 (d, 2H, JHH ) 2.4 Hz, 4-C6H2 Bu2), 7.15 (d, 2H, JHH
) 2.4 Hz, 6-C6H2 Bu2), 4.06 (d, 2H, JHH ) 12.6 Hz, NCH2Ph),
[Ti(tBu2O2NN′)(K2-CH2C6H4NMe2)] (5). A solution of LiCH2-
(2-NMe2)C6H4 (0.14 g, 1.00 mmol) in toluene was added to a
solution of [TiCl(tBu2O2NN′)(THF)] (0.68 g, 1.00 mmol) in the same
solvent, at -70 °C. The temperature was allowed to rise slowly to
room temperature, and the solution was further stirred overnight.
The green solution obtained was evaporated to dryness, and the
residue was extracted in hexane and filtered off. Evaporation of
the solvent to dryness led to 5 as a green microcrystalline solid in
92% yield (0.65 g, 0.92 mmol). Crystals suitable for X-ray
diffraction analysis were grown from hexane at -20 °C. µeff (20
°C) ) 1.55 µB. Anal. Calcd for C43H66N3O2Ti: C, 73.27, H, 9.44,
N, 5.96. Found: C, 69.66, H, 9.65, N, 5.54 (attempts to obtain good
elemental analysis were hampered by the extreme instability of the
compound).
t
t
3.29 (4H, NCH2CH2N(CH3)2 + 4H, CH3OCH2CH2OCH3), 3.18 (s,
6H, CH3OCH2CH2OCH3), 2.89 (d, 2H, JHH ) 12.6 Hz, NCH2Ph),
t
2.03 (s, 6H, N(CH3)2), 1.76 (s, 18H, 3-C6H2 Bu2), 1.45 (s, 18H,
t
1
5-C6H2 Bu2). H NMR (δ, ppm, tol-d8, -70 °C): 7.70, 7.61 (1H,
t
t
1H, 4-C6H2 Bu2), 7.26, 7.21 (1H, 1H, 6-C6H2 Bu2), 4.05, 3.97
(d, d, 1H, 1H, JHH ) 12.6 Hz, JHH ) 12.6 Hz, NCH2Ph), 3.30 (br,
4H, NCH2CH2N(CH3)2 + 4H, CH3OCH2CH2OCH3), 3.02, 2.98 (3H,
3H, CH3OCH2CH2OCH3), 2.83, 2.78 (d, d, 1H, 1H, JHH ) 12.6
Hz, JHH ) 12.6 Hz, NCH2Ph), 2.24, 2.17 (3H, 3H, N(CH3)2), 1.91,
t
1.76 (s, s, 9H, 9H, 3-C6H2 Bu2), 1.53, 1.52 (s, s, 9H, 9H,
5-C6H2 Bu2). 13C(1H) NMR (δ, ppm, C6D6): 160.9 (2-C6H2 Bu2),
t
t
t
t
t
137.1 (5-C6H2 Bu2), 136.6 (3-C6H2 Bu2), 125.5 (6-C6H2 Bu2), 125.1
[Y(tBu2O2NN′)(K2-CH2C6H4NMe2) (6). A solution of LiCH2-(2-
NMe2)C6H4 (0.054 g, 0.38 mmol) in THF was added at room
temperature to a solution of Y(tBu2O2NN′)Cl(DME) (0.28 g, 0.38
mmol) in the same solvent. The mixture was stirred overnight, and
the solvent was evaporated to dryness to give a cream powder.
After washing with hexane the compound was extracted in toluene
and filtered. Removal of the solvent under vacuum led to a pale
yellow powder in 78% yield (0.22 g; 0.30 mmol). Diffraction-
quality crystals were grown by slow evaporation of a toluene
t
t
(4-C6H2 Bu2), 124.5 (1-C6H2 Bu2), 70.4 (CH2 of DME), 65.9
(NCH2Ph), 59.9 (CH3OCH2CH2OCH3), 59.6 (NCH2CH2NMe2),
50.4 (NCH2CH2NMe2), 47.1 (N(CH3)2), 35.6 (3-C6H2(CMe3)2), 34.3
(5-C6H2(CMe3)2), 32.2 (5-C6H2(CMe3)2), 30.5 (3-C6H2(CMe3)2).
Anal. Calcd for C38ClH64N2O4Y: C, 61.90, H, 8.75, N, 3.80. Found:
C, 61.51, H, 8.40, N, 3.87.
[Y(tBu2O2NN′)(N(SiMe3)2] (4). To a solution of [Y(tBu2O2NN′)-
Cl(DME)] (0.88 g, 1.20 mmol) in THF was added a solution of
KN(SiMe3)2 (0.24 mg, 1.20 mmol) in the same solvent at room
temperature. After stirring overnight the potassium chloride was
separated by centrifugation and the solvent removed under vacuum.
1
solution. H NMR (δ, ppm, C6D6): 7.62 (d, 1H, JHH ) 7.5 Hz,
t
C6H4CH2NMe2), 7.55 (d, 2H, JHH ) 2.4 Hz, 4-C6H2 Bu2), 7.27 (d,
1H, JHH ) 7.5 Hz, C6H4CH2NMe2), 7.18 (t, 1H, C6H4CH2NMe2),
1
t
Yield: 82% (0.76 g, 0.92 mmol). H NMR (δ, ppm, C6D6): 7.55
7.04 (d, 2H, JHH ) 2.4 Hz, 6-C6H2 Bu2), 6.93 (t, 1H, C6H4-
t
(d, 2H, JHH ) 2.7 Hz, 4-C6H2 Bu2), 6.96 (d, 2H, JHH ) 2.7 Hz,
CH2NMe2), 4.10 (s, 2H, CH2C6H4NMe2), 3.80, 2.85 (d, d, 2H, 2H,
JHH ) 12.3 Hz, JHH ) 12.3 Hz, NCH2Ph), 2.80 (s, 6H, N(CH3)2),
2.19, 1.91 (m, 2H, 2H, NCH2CH2N(CH3)2), 1.66 (s, 6H, N(CH3)2),
t
6-C6H2 Bu2), 3.58 (br, 4H, NCH2Ph), 2.17 (m, 4H, NCH2CH2-
t
N(CH3)2), 1.76 (s, 6H, N(CH3)2), 1.67 (s, 18H, 3-C6H2 Bu2), 1.40
t
1
t
t
(s, 18H, 5-C6H2 Bu2), 0.45 (s, 18H, N(Si(CH3)3)2). H NMR (δ,
1.50 (s, 18H, 3-C6H2 Bu2), 1.44 (s, 18H, 5-C6H2 Bu2). Anal. Calcd
for C43H66N3O2Y: C, 69.24, H, 8.92, N, 5.63. Found: C, 68.90, H,
8.51, N, 5.71.
t
ppm, tol-d8): 7.54 (d, 2H, JHH ) 2.7 Hz, 4-C6H2 Bu2), 6.94 (d, 2H,
t
JHH ) 2.7 Hz, 6-C6H2 Bu2), 3.49, 3.27 (d, d, 2H, 2H, JHH ) 12.6
[Y(tBu2O2NN′)(K2-C6H4CH2NMe2) (7). To
a solution of
Hz, JHH ) 12.6 Hz, NCH2Ph), 2.17 (m, 4H, NCH2CH2N(CH3)2),
t
[YCl(tBu2O2NN′)(DME)] (0.53 g, 0.72 mmol) in THF was added
dropwise a solution of Li[2-(CH2NMe2)C6H4] (0.10 g, 0.72 mmol)
in THF at room temperature, and the solution was stirred for 5 h.
The resulting solution was evaporated to give a cream powder,
which was extracted into toluene and filtered, and the solution was
evaporated to dryness to give a white powder. Yield: 0.53 g (99%).
1.76 (s, 6H, N(CH3)2), 1.68 (s, 18H, 3-C6H2 Bu2), 1.40 (s, 18H,
t
1
5-C6H2 Bu2), 0.45 (s, 18H, N(Si(CH3)3)2). H NMR (δ, ppm, tol-
d8, -70 °C): 7.63, 7.56, (1H, 1H, 4-C6H2 Bu2), 7.24, 6.67 (1H, 1H,
6-C6H2 Bu2), 4.16, 4.05, 2.84, 2.65 (1H, 1H, 1H, 1H, NCH2Ph),
t
t
2.17 (m, 4H, NCH2CH2N(CH3)2), 1.78, 1.69 (s, s, 9H, 9H,
t
t
3-C6H2 Bu2), 1.54, 1.38 (s, s, 9H, 9H, 5-C6H2 Bu2), 0.63, 0.39 (s, s,

Ti and Y Diamine Bis(phenolate)
Organometallics, Vol. 28, No. 12, 2009 3457
Table 6. Crystallographic Data for 3 · 0.5(O2C4H10), 4, 6 · (C7H8), 7, 8, and 9
3 · 0.5(O2C4H10)
4
6
7 · C7H8
8
9
empirical formula
fw
C80H138Cl2N4O10Y2
1564.66
C40H72N32O2Si2Y
772.10
C43H66N3O2Y
745.90
C50H74N3O2Y
838.03
C76H130Li2N4O5Si2Y2
1427.72
C47H72N5O2Y
828.01
temp (K)
cryst syst, space group
a (Å)
b (Å)
c (Å)
130(2)
triclinic P1
148(2)
150(2)
150(2)
108(2)
150(2)
triclinic P1
j
j
monoclinic Cc
19.0586(9)
24.5350(13)
10.4449(6)
90
111.207(3)
90
4553.3(4)
4, 1.126
1.366
monoclinic P21/n
7416(4)
20.4043(7)
17.4481(5)
90
100.166(2)
90
4114.6(2)
4, 1.204
1.454
monoclinic P21/n
11.6585(4)
17.8023(6)
23.0721(10)
90
100.487(2)
90
4708.6(3)
4, 1.182
1.278
monoclinic C2/c
21.905(6)
18.189(5)
20.000(5)
90
105.134(17)
90
7 692(4)
4, 1.233
1.582
12.782(5)
17.655(6)
19.626(8)
89.74(3)
88.63(2)
85.35(2)
4413(3)
2, 1.178
1.422
11.2064(4)
15.2939(5)
16.0307(6)
115.518(2)
91.676(2)
111.069(2)
2257.74(14)
2, 1.218
R (deg)
ꢀ (deg)
γ (deg)
V (Å3)
Z, Dcalc (g cm-3
)
µ(mm-1
reflns measd
)
1.333
17 228
43 837
11 007
36 635
43 907
80 574
unique reflns [R(int)]
obsd reflns [I > 2σ(I)]
R1
14 343 [0.1518]
7514
0.1366
5980 [0.0707]
4711
0.0523
7800 [0.0910]
5052
0.0434
8609 [0.0830]
5944
0.0451
7016 [0.1448]
3875
0.0534
7943 [0.0672]
5629
0.0551
wR2
0.3593
0.1043
0.0886
0.0973
0.1089
0.1116
Diffraction-quality crystals were grown by slow evaporation of a
(NC(PhCH2N(CH3)2)CHC(CH3)NH), 4.35, 3.97, 3.58, 3.17 (d, 4H,
JHH ) 12.3 Hz, NCH2Ph), 3.73 (s, 2H, C6H4CH2N(CH3)2), 2.76
(br, 2H, NCH2CH2N(CH3)2), 2.39, 2.38, 2.35 (s, s, s, 3H, 3H, 6H,
N(CH3)2), 2.27 (br, 2H, NCH2CH2N(CH3)2), 2.21 (s, 3H, (NC-
(PhCH2N(CH3)2)CHC(CH3)NH), 1.65, 162 (s, s, 9H, 9H,
toluene solution. 1H NMR (δ, ppm, C6D6): 7.72 (d, 1H, JHH ) 4.2
t
Hz, C6H4CH2NMe2), 7.45 (d, 2H, JHH ) 2.4 Hz, 4-C6H2 Bu2), 7.26
(t, 1H, C6H4CH2NMe2), 7.20 (d, 1H, JHH ) 4.2 Hz, C6H4CH2NMe2),
7.18 (br, 1H, C6H4CH2NMe2), 7.08 (d, 2H, JHH ) 2.4 Hz,
t
3-C6H2 Bu2), 1.46, 1.44 (s, s, 9H, 9H, 5-C6H2 Bu2). 13C(1H) NMR
t
t
6-C6H2 Bu2), 4.16 (s, 2H, C6H4CH2NMe2), 3.89, 2.83 (d, d, 2H,
2H, JHH ) 12.3 Hz, JHH ) 12.3 Hz, NCH2Ph), 2.46 (s, 6H,
N(CH3)2), 2.25, 2.10 (m, 2H, 2H, NCH2CH2N(CH3)2), 1.79 (s, 6H,
(δ, ppm, THF-d8): 170.9, 168.8 (NC(PhCH2N(CH3)2)CHC(CH3)-
t
NH), 163.2, 162.7 (2-C6H2 Bu2), 143.7 (C6H4CH2NMe2), 136.5,
t
t
N(CH3)2), 1.55 (s, 18H, 3-C6H2 Bu2), 1.45 (s, 18H, 5-C6H2 Bu2).
t
t
136.2 (5-C6H2 Bu2), 135.6, 135.4 (3-C6H2 Bu2), 131.6, 129.8, 128.8,
13C(1H)NMR (δ, ppm, C6D6): 161.8 (2-C6H2 Bu2), 148.2, 138.6,
128.3, 126.1, 125.9, 125.6 (C6H4CH2NMe2), 137.5 (5-C6H2 Bu2),
136.5 (3-C6H2 Bu2), 126.2 (6-C6H2 Bu2), 125.0 (4-C6H2 Bu2), 126.0
(1-C6H2 Bu2), 68.1 (C6H4CH2NMe2), 65.4 (NCH2Ph), 60.3, 48.7
t
t
128.3, 127.8 (C6H4CH2NMe2), 126.3, 126.1 (6-C6H2 Bu2), 123.9,
t
t
t
123.8 (4-C6H2 Bu2), 125.1 (1-C6H2 Bu2), 94.3 (NC(PhCH2N(CH3)2)-
CHC(CH3)NH), 61.9 (C6H4CH2NMe2), 67.1, 64.5 (NCH2Ph), 60.5,
51.9 (NCH2CH2N(CH3)2), 48.1, 46.0, 45.1 (N(CH3)2), 35.9, 35.8
(3-C6H2(CMe3)2), 34.5, 34.5 (5-C6H2(CMe3)2), 32.6, 32.4 (5-
C6H2(CMe3)2), 31.3, 30.7 (3-C6H2(CMe3)2), 26.8 (NC(PhCH2NMe2)-
CHC(CH3)NH). Anal. Calcd for C47H72N5O2Y: C, 68.18, H, 8.76,
N, 8.46. Found: C, 68.02, H, 8.53, N, 8.07.
t
t
t
t
(NCH2CH2N(CH3)2), 46.6 (N(CH3)2), 45.5 (N(CH3)2), 35.7 (3-
C6H2(CMe3)2), 34.6 (5-C6H2(CMe3)2), 32.6 (5-C6H2(CMe3)2), 30.9
(3-C6H2(CMe3)2). Anal. Calcd for C43H66N3O2Y · C7H8: C, 71.66,
H, 8.90, N, 5.01. Found: C, 70.06, H, 8.68, N, 4.95.
Li2(µ4-O)[Y(tBu2O2NN′)(CH2SiMe3)]2 (8). To a solution of
[YCl(tBu2O2NN′)(DME)] (0.40 g, 0.54 mmol) in THF was slowly
added a solution of LiCH2SiMe3 (0.05 g, 0.54 mmol) in the same
solvent, at room temperature. After stirring for 5 h the solution
was evaporated to dryness and the residue extracted in toluene and
filtered. Removal of the solvent gave a white powder, which was
recrystallized from THF to give 8. Yield in crude product, based
1H NMR Data for [Y(tBu2O2NN′)(K2-NC(CH3)C6H4CH2NMe2]
(10). 1H NMR (δ, ppm, C6D6): 7.91 (m, 1H, C6H4CH2NMe2), 7.54
t
(d, 2H, JHH ) 2.7 Hz, 4-C6H2 Bu2), 7.24 (m, 1H, C6H4CH2NMe2),
7.13 (m, 1H, C6H4CH2NMe2), 7.10 (m, 1H, C6H4CH2NMe2), 7.06
t
(d, 2H, JHH ) 2.7 Hz, 6-C6H2 Bu2), 3.75 (d, 2H, JHH ) 9.6 Hz,
NCH2Ph), 3.72 (d, 2H, JHH ) 9.6 Hz, NCH2Ph), 2.41 (2H,
NCH2CH2N(CH3)2), 2.25 (s, 6H, N(CH3)2), 2.10 (2H, NCH2CH2-
on Y: 0.38 g (49%). 1H NMR (δ, ppm, C6D6): 7.61 (d, 2H, JHH
2.4 Hz, 4-C6H2 Bu2), 7.12 (d, 2H, JHH ) 2.4 Hz, 6-C6H2 Bu2), 3.74
(d, 2H, JHH ) 12.3 Hz, NCH2Ph), 2.87 (d, 2H, JHH ) 12.3 Hz,
NCH2Ph), 2.28, 2.10 (2H, 2H, NCH2CH2N(CH3)2), 1.79 (s, 18H,
)
t
t
t
N(CH3)2), 1.65 (s, 6H, N(CH3)2), 1.50 (s, 18H, 3-C6H2 Bu2), 1.46
t
(s, 3H, NdC(CH3)), 1.44 (s, 18H, 5-C6H2 Bu2).
General Procedures for X-ray Crystallography. Pertinent
details for the individual compounds can be found in Tables 5 and 6.
t
t
3-C6H2 Bu2), 1.71 (6H, N(CH3)2), 1.45 (s, 18H, 5-C6H2 Bu2), 0.50
(s, 9H, Si(CH3)3), -0.42 (2H, CH2SiMe3). 13C(1H) NMR (δ, ppm,
C6D6): 161.7 (2-C6H2 Bu2), 136.9 (5-C6H2 Bu2), 136.4 (3-C6H2 Bu2),
t
t
t
Crystallographic data for compounds 1-9 were collected using
graphite-monochromated Mo KR (R ) 0.71073 Å) on a Bruker
AXS-KAPPA APEX II area detector diffractometer equipped with
an Oxford Cryosystem open-flow nitrogen cryostat, and data were
collected at 150 K. Cell parameters were retrieved using Bruker
SMART software and refined using Bruker SAINT on all observed
reflections. Absorption corrections were applied using SADABS.51
The structures were solved by direct methods using either SHELXS-
97,52 SIR 97,53 or SIR200454 and refined using full-matrix least-
t
t
t
125.6 (6-C6H2 Bu2), 124.6 (4-C6H2 Bu2), 113.2 (1-C6H2 Bu2), 65.4
(NCH2Ph), 60.0, 48.4 (NCH2CH2N(CH3)2), 46.3 (N(CH3)2), 35.7
(3-C6H2(CMe3)2), 34.2 (5-C6H2(CMe3)2), 32.2 (5-C6H2(CMe3)2),
30.6 (3-C6H2(CMe3)2), 25.1 (CH2SiMe3), 4.9 (Si(CH3)3). Anal.
Calcd for C76H130Li2N4O5Si2Y2: C, 63.94, H, 9.18, N, 3.92. Found:
C, 63.64, H, 9.16, N, 3.99.
[Y(tBu2O2NN′)(K2-N(H)C(CH3)C(H)C(C6H4CH2NMe2)N(H))]
(9). Excess CH3CN (0.028 g, 0.672 mmol) was added to a solution
of [Y(tBu2O2NN′)(C6H4CH2N(CH3)2)], (0.125 g, 0.168 mmol) in
toluene at room temperature. The color of the solution changed to
yellow immediately. Stirring was continued overnight. The resulting
solution was evaporated under vacuum to give a cream powder,
which was extracted into hexane. Diffraction-quality crystals were
obtained by slow evaporation of a hexane solution. Yield: 0.138 g
(99.2%). 1H NMR (δ, ppm, THF-d8): 7.70 (d, 1H, JHH ) 7.24 Hz,
C6H4CH2N(CH3)2), 7.52 (m, 1H, C6H4CH2N(CH3)2), 7.42 (m, 1H,
C6H4CH2N(CH3)2), 7.40 (m, 1H, C6H4CH2N(CH3)2), 7.34, 7.33 (m,
(51) SADABS: Area-Detector Absorption Correction; Siemens Industrial
Automation, Inc., Madison, WI, 1996.
(52) Sheldrick, G. M. SHELXL-97: A program for refining crystal
structures; Univ. of Go¨ttingen: Germany, 1998.
(53) Altomare, A.; Burla, M. C.; Camalli, M.; Cascarano, G.; Giaco-
vazzo, C.; Guagliardi, A.; Moliterni, A. G. G.; Polidori, G.; Sparna, R.
J. Appl. Crystallogr. 1999, 32, 115.
(54) Burla, M. C.; Caliandro, R.; Camalli, M.; Cascarano, G.; De Caro,
L.; Giacovazzo, C.; Polidori, G.; Sparna, R. J. Appl. Crystallogr. 2005, 38,
381.
t
t
2H, 4-C6H2 Bu2), 7.04, 7.02 (m, 2H, 6-C6H2 Bu2), 4.79 (s, 1H,

3458 Organometallics, Vol. 28, No. 12, 2009
Barroso et al.
squares refinement against F2 using SHELXL-97.52 All programs
are included in the package of programs WINGX-version 1.64.05.55
Crystals of 1 have been obtained from Et2O at -20 °C with two
molecules and one cocrystallized solvent molecule in the unit cell.
One of the molecules presents disorder in one tBu fragment, which
was modeled and gave 40% and 60% occupancy. The same
complex was isolated from hexane,56 and the data collected are
not included here due to strong disorder in the crystal. Complexes
2 and 5 were obtained from toluene and hexane, respectively.
Crystals of 5 have low quality and poor diffracting power,
applied refining anisotropically and converging to occupancies of
54/46% and 61/39%, respectively.
All non-hydrogen atoms were refined anisotropically (except in
5 due to the poor quality of the crystal), and all hydrogen atoms
were placed in idealized positions and allowed to refine riding on
the parent carbon atom. The molecular structures were drawn with
ORTEP3 for Windows.57
Data for complexes 1-9 were deposited in CCDC under the
deposit numbers CCDC 720956-720964 and can be obtained free
of charge from The Cambridge Crystallographic Data Centre via
www.ccdc.cam.uk/data_request/cif.
t
presenting disordered Bu moieties (40/60%). Crystals of 3 have
low quality and poor diffracting power; even so, the structure was
unequivocally determined and is in agreement with the remaining
characterization data. In compounds 4 and 7 high anisotropic
displacement parameters were found in one of the tBu substituents,
and a disorder model was applied refining anisotropically and
converging to occupancies of 50/50% and 80/20%, respectively.
In compound 8, high anisotropic displacement parameters were
Acknowledgment. The authors thank Fundac¸a˜o para a
Cieˆncia e a Tecnologia, Lisbon, Portugal, for funding (PTDC/
QUI/66187/2006, SFRH/BD/28762/2006).
Supporting Information Available: Tables with atomic coor-
dinates of all optimized species. X-ray crystallographic data for
compounds 1-9 are available as an electronic file in cif format.
This material is available free of charge via the Internet at
http://pubs.acs.org.
t
found in two of the Bu substituents, and a disorder model was
(55) Farrugia, L. J. J. Appl. Crystallogr. 1997, 30, 565.
(56) From hexane, the complex crystallizes in the triclinic system, space
group P, with cell parameters a ) 9.865(3) Å, b ) 17.448(4) Å, c ) 28.
461(6) Å, R ) 78.799(13)°, ꢀ ) 83.304(11)°, γ ) 88.800(11)°, V ) 4772(2)
Å3.
OM9001389
(57) Farrugia, L. J. J. Appl. Crystallogr. 1997, 30, 565.