Small Molecule Activation Mediated by a Thorium Terminal Imido Metallocene

Article abstract of DOI:10.1021/acs.organomet.5b00454

(Chemical Equation Presented). The base-free thorium terminal imido [η⁵-1,2,4-(Me₃C)₃C₅H₂]₂Thi=N(p-tolyl) (1) activates a variety of small molecules such as pyridine derivatives, amines, boranes, chlorosilane, elemental selenium, and α,β-unsaturated esters. Reaction of 1 with pyridine, pyridine N-oxide, 2-methylpyridine N-oxide, p-toluidine, Ph₂NH, 9-borabicyclo[3.3.1]nonane (9-BBN), PhSiH₂Cl, elemental selenium, PhSeSePh, and methyl methacrylate (MMA) formed the amido pyridyl complexes [η⁵-1,2,4-(Me₃C)₃C₅H₂]₂Th(NH-p-tolyl)(η²-C,N-C₅H₄N) (2), [η⁵-1,2,4-(Me₃C)₃C₅H₂]₂Th(NH-p-tolyl)(κ²-C,O-C₅H₄NO) (3), and [η⁵-1,2,4-(Me₃C)₃C₅H₂]₂Th(NH-p-tolyl)(κ²-C,O-2-MeC₅H₃NO) (4), diamide complexes [η⁵-1,2,4-(Me₃C)₃C₅H₂]₂Th(NH-p-tolyl)₂ (5) and [η⁵-1,2,4-(Me₃C)₃C₅H₂]₂Th(NH-p-tolyl)(NPh₂) (6), amido hydrido complex [η⁵-1,2,4-(Me₃C)₃C₅H₂]₂Th(H)[N(p-tolyl)B(C₈H₁₄)] (7), amido chloride complex [η⁵-1,2,4-(Me₃C)₃C₅H₂]₂Th(Cl)[N(p-tolyl)SiH₂Ph] (8), amido selenido complexes [η⁵-1,2,4-(Me₃C)₃C₅H₂]₂Th[N(p-tolyl)Se-Se] (9) and {[η⁵-1,2,4-(Me₃C)₃C₅H₂]Th(SePh)}₂[μ-N(p-tolyl)]₂ (10), and amido enolyl complex [η⁵-1,2,4-(Me₃C)₃C₅H₂]₂Th[N(p-tolyl)CH₂C(Me)=C(OMe)O] (11). The new complexes 2-3 and 6-11 were characterized by various spectroscopic techniques including single crystal X-ray diffraction. Furthermore, density functional theory (DFT) studies complement the experimental investigations.

Full text of DOI:10.1021/acs.organomet.5b00454

Article
pubs.acs.org/Organometallics
Small Molecule Activation Mediated by a Thorium Terminal Imido
Metallocene
Enwei Zhou,†,§ Wenshan Ren,†,§ Guohua Hou,† Guofu Zi,*,† De-Cai Fang,*,† and Marc D. Walter*,‡
†Department of Chemistry, Beijing Normal University, Beijing 100875, China
‡Institut fur Anorganische und Analytische Chemie, Technische Universitat Braunschweig, Hagenring 30, 38106 Braunschweig,
̈
̈
Germany
S
* Supporting Information
ABSTRACT: The base-free thorium terminal imido [η5-1,2,4-
(Me3C)3C5H2]2ThN(p-tolyl) (1) activates a variety of small
molecules such as pyridine derivatives, amines, boranes,
chlorosilane, elemental selenium, and α,β-unsaturated esters.
Reaction of 1 with pyridine, pyridine N-oxide, 2-methylpyr-
idine N-oxide, p-toluidine, Ph2NH, 9-borabicyclo[3.3.1]-
nonane (9-BBN), PhSiH2Cl, elemental selenium, PhSeSePh,
and methyl methacrylate (MMA) formed the amido pyridyl
complexes [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)(η2-C,N-
C5H4N) (2), [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)(κ2-
C,O-C5H4NO) (3), and [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)(κ2-C,O-2-MeC5H3NO) (4), diamide complexes [η5-1,2,4-
(Me3C)3C5H2]2Th(NH-p-tolyl)2 (5) and [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)(NPh2) (6), amido hydrido complex [η5-
1,2,4-(Me3C)3C5H2]2Th(H)[N(p-tolyl)B(C8H14)] (7), amido chloride complex [η5-1,2,4-(Me3C)3C5H2]2Th(Cl)[N(p-tolyl)-
SiH2Ph] (8), amido selenido complexes [η5-1,2,4-(Me3C)3C5H2]2Th[N(p-tolyl)Se−Se] (9) and {[η5-1,2,4-(Me3C)3C5H2]Th-
(SePh)}2[μ-N(p-tolyl)]2 (10), and amido enolyl complex [η5-1,2,4-(Me3C)3C5H2]2Th[N(p-tolyl)CH2C(Me)C(OMe)O]
(11). The new complexes 2−3 and 6−11 were characterized by various spectroscopic techniques including single crystal X-ray
diffraction. Furthermore, density functional theory (DFT) studies complement the experimental investigations.
acetylenes,9 an efficient catalyst for the trimerization of
1. INTRODUCTION
PhCN,9 and a useful synthon for the preparation of oxido
Terminal imido complexes of actinide-metals containing an
and s ulfid o thorium met all ocene s [ η5 -1, 2, 4-
AnN double bond have been widely studied in the last two
(Me3C)3C5H2]2ThE (E = O, S) by cycloaddition−
decades mainly because of their potential application in group
elimination reactions with Ph2CE (E = O, S).8 Encouraged
transfer reactions and catalysis.1−4 During these investigations,
by this broad reactivity, we are now extending our studies to
many uranium imido complexes have been prepared, but only
small molecule activation mediated by 1. Herein, we report on
some of them show significant reactivity, and most studies have
some observations concerning the reactions of the imido
therefore focused on their structural characterizations.1−3 In
thorium metallocene 1 with pyridine derivatives, amines,
contrast, only a small number of thorium imido complexes have
boranes, chlorosilane, selenium, and its organic derivatives,
been reported.3j,4 The lack of interest in thorium organo-
and α,β-unsaturated organic molecules.
metallics is surprising since its 7s26d2 electronic ground state
configuration suggests a similar reactivity to that of group 3 and
2. RESULTS AND DISCUSSION
4 metals, such as Sc, Ti, Zr, and Hf, for which several complexes
with MNR bonds are known,5,6 and the diamagnetism of
2.1. Reaction with Pyridine Derivatives. Mixing the
thorium imido [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1)
Th(IV) complexes also facilitates the NMR spectroscopic
with pyridine derivatives such as pyridine, pyridine N-oxide, or
2-methylpyridine N-oxide rapidly forms the amido pyridyl
complexes [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)(η2-C,N-
C5H4N) (2), [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)(κ2-
C,O-C5H4NO) (3), and [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-
tolyl)(κ2-C,O-2-MeC5H3NO) (4), respectively, in quantitative
conversions (Scheme 1), in which an α-H atom of pyridine,
pyridine N-oxide, or 2-methylpyridine N-oxide is transferred to
characterization. Nevertheless, more recent studies indicate that
5f orbitals play a significant part in the bonding of
organothorium compounds, thus leading to a distinctively
different reactivity from that of group 4 complexes.7 In the
course of our investigations in this area, we have recently
prepared a base-free terminal thorium imido metallocene [η5-
1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1).8−10 Gratifyingly,
complex 1 shows a rich reaction chemistry including the
activation of element sulfur,9 Si−H bonds,11 and NN bonds
in diazoalkanes.12 Furthermore, it is also an important
intermediate in the catalytic hydroamination of internal
Received: May 27, 2015
Published: July 2, 2015
© 2015 American Chemical Society
3637
DOI: 10.1021/acs.organomet.5b00454
Organometallics 2015, 34, 3637−3647

Organometallics
Article
Th(NH-p-tolyl)(κ2-C,O-C5H4NO) (3) and [η5-1,2,4-
(Me3C)3C5H2]2Th(NH-p-tolyl)(κ2-C,O-2-MeC5H3NO) (4)
were determined and are shown in Figures 2−4, while selected
Scheme 1
the imido ThN(p-tolyl) moiety. For 2-methylpyridine N-
oxide, no activation of sp3 C−H bond of methyl was observed,
indicating that the sp2 C−H bond is more reactive than the sp3
C−H bond. To further understand this transformation, DFT
calculations were performed at the B3PW91 level of theory.
The energetic profile for the intermolecular reaction of 1 with
pyridine N-oxide is shown in Figure 1, and it involves the
Figure 2. Molecular structure of 2 (thermal ellipsoids drawn at the
35% probability level).
Figure 1. Free energy profile (kcal/mol) for the reaction of 1 + PyNO.
[Th] = [η5-1,2,4-(Me3C)3C5H2]Th. R = p-tolyl.
formation of the adduct COM and the transition state TS. In
the σ-bond metathesis transition state TS, the two forming
bond distances of Th−C and N−H are 3.581 and 1.295 Å,
respectively, ca. 0.93 and 0.27 Å longer than those in the
product 3. The Th−C and N−H bonds are formed
simultaneously, while the C−H bond is broken. The formation
of the adduct COM from 1 + PyO is energetically favorable
(ΔG(298 K) = −25.6 kcal/mol), but the final product 3 is
thermodynamically more stable (−30.1 kcal/mol) than the
adduct COM. Moreover, the potential energy profile suggests a
short lifetime for the adduct COM since the activation barrier
to form complex 3 from intermediate COM is only 12.7 kcal/
mol. Therefore, COM is not isolated from the reaction mixture,
and only 3 is detected by NMR spectroscopy.
Figure 3. Molecular structure of 3 (thermal ellipsoids drawn at the
35% probability level).
bond distances and angles are listed in Table 1. In each
complex, the Th4+ ion features a pseudotetrahedral ligand
environment with two η5-bound Cp-ring and one σ-coordinate
carbon atom and two nitrogen atoms (for 2) or one oxygen
atom and one nitrogen atom (for 3 and 4) with the average
Th−C(Cp) distance of 2.886(5) Å for 2, 2.897(7) Å for 3, and
2.882(3) Å for 4, respectively, and the angle Cp(cent)-Th-
Cp(cent) of 137.8(2)° for 2, 139.3(3)° for 3, and 141.1(1)° for
4, and the angle of Th−N−C of 160.4(4)° for 2, 159.3(6)° for
3, and 155.7(2)° for 4. The Th−N(1) distances (2.257(5) Å
for 2, 2.283(7) Å for 3, and 2.322(3) Å for 4) can be compared
The molecular structures of [η5-1,2,4-(Me3C)3C5H2]2Th-
(NH-p-tolyl)(η2-C,N-C5H4N) (2), [η5-1,2,4-(Me3C)3C5H2]2-
3638
DOI: 10.1021/acs.organomet.5b00454
Organometallics 2015, 34, 3637−3647

Organometallics
Article
(2.257(5)−2.322(3) Å) of Th−N(1) in 2, 3, and 4. In 3 and
4, the Th−O distances (2.460(5) Å for 3 and 2.378(4) Å for 4)
are shorter than that expected for a purely dative interaction.16
These values may also be compared to those found in (η5-
C5Me5)2Th(CH2Ph)(κ2-C,O-ONC5H4) (2.416(2) Å),14 but
they are longer than those observed in [η5-1,2,4-
(Me3C)3C5H2]2Th[O2CPh2] (2.202(3) Å),8 and [η5-1,2,4-
(Me3C)3C5H2]2Th[(OCPh2)2] (2.182(2) Å).17 The N−O
distances (1.360(10) Å for 3 and 1.310(5) Å for 4) are in
the same range as those in the free pyridine N-oxide (1.330(9)
Å)18 and in (η5-C5Me5)2Th(CH2Ph)(κ2-C,O-ONC5H4)
(1.360(3) Å).14
2.2. Reaction with Amines. It has been demonstrated that
diamide [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)2 (5) is read-
ily formed on the reaction of imido [η5-1,2,4-(Me3C)3C5H2]2-
ThN(p-tolyl) (1) and p-toluidine (Scheme 2),9 indicating
Scheme 2
Figure 4. Molecular structure of 4 (thermal ellipsoids drawn at the
35% probability level).
to those found in [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)2
(2.279(3) and 2.286(3) Å),9 [η5-1,2,4-(Me3C)3C5H2]2Th[N-
(p-tolyl)C(S)-S] (2.347(6) Å),8 [η5-1,2,4-(Me3C)3C5H2]2Th-
[N(p-tolyl)C(NPh)-S] (2.328(3) Å),8 [η5-1,2,4-
(Me3C)3C5H2]2Th[N(p-tolyl)NNN(p-tolyl)] (2.366(3)
and 2.354(3) Å),12 [η5-1,2,4-(Me3C)3C5H2]2Th(bipy)
(2.325(5) and 2.363(4) Å),10 and [η5-1,3-(Me3C)2C5H3]2Th-
(bipy) (2.326(7) and 2.325(7) Å).13 However, the Th−
C(pyridyl) distance of 2.486(5) Å in 2 is shorter than those
found in 3 (2.687(7) Å), 4 (2.690(3) Å), and (η5-C5Me5)2-
Th(CH2Ph)(κ2-C,O-ONC5H4) (2.621(3) Å).14 In 2, the Th−
N(2) distance (2.497(5) Å) is as expected shorter than those
observed in [η5-1,2,4-(Me3C)3C5H2]2ThO(4-Me2NC5H4N)
(2.587(5) Å)8 and [η5-1,2,4-(Me3C)3C5H2]2Th[(bipy)-
(SCPh2)] (2.564(1) Å)15 but slightly longer than those
that imido 1 activates the N−H bond in aromatic amines.
Diamide 5 can be converted to imido 1 at approximately 140
°C/0.01 mmHg, but no equilibrium between diamide 5 and
imido 1 is detected by 1H NMR spectroscopy (in the
temperature range of 20−100 °C) because of the rather small
amount of formed imido or rapid chemical exchange.9 Under
similar reaction conditions, reaction of 1 with 1 equiv of
Ph2NH also affords the desired mixed diamide [η5-1,2,4-
(Me3C)3C5H2]2Th(NH-p-tolyl)(NPh2) (6) (Scheme 2). In
contrast to diamide 5, an equilibrium between diamide 6 and
1
imido 1 is detected at temperatures above 80 °C by H NMR
a
Table 1. Selected Distances (Å) and Angles (deg) for Compounds 2−4 and 6−11
b
c
b
compound C(Cp)-Th
C(Cp)-Th
Cp(cent)-Th
2.621(5)
Th-X
Cp(cent)-Th-Cp(cent)
137.8(2)
X-Th-X or X-Th-Y
2
3
4
2.886(5)
2.897(7)
2.882(3)
2.801(4) to 3.005(5)
2.807(7) to 2.933(7)
2.813(3) to 2.945(3)
N(1) 2.257(5), N(2) 2.497(5)
C(42) 2.486(5)
N(1)-Th-N(2) 86.1(2)
N(2)-Th-C(42) 29.2(2)
O(1)-Th-C(46) 53.5(3)
2.625(7)
2.619(3)
N(1) 2.283(7), O(1) 2.460(5)
C(46) 2.687(7)
139.3(3)
141.1(1)
N(1) 2.322(3), O(1B) 2.378(4)
C(46B) 2.690(3)
O(1)-Th-C(46B) 53.7(1)
6
2.890(5)
2.853(3)
2.878(3)
2.869(5)
2.851(5)
2.835(6) to 2.934(5)
2.783(3) to 2.939(3)
2.824(3) to 2.964(3)
2.797(5) to 2.995(5)
2.778(5) to 2.903(5)
2.789(11) to 3.033(11)
2.639(5)
2.584(3)
2.613(3)
2.603(5)
2.584(5)
2.623(11)
N(1) 2.418(5), N(2) 2.266(4)
N(1) 2.421(2), H(1) 1.96(3)
N(1) 2.389(2), Cl(1) 2.663(1)
N(1) 2.322(5), Se(1) 2.906(1)
N(1) 2.170(5), Se(1) 2.918(1)
N(1) 2.323(9), O(1) 2.197(9)
130.4(3)
132.9(1)
135.9(1)
133.8(3)
91.2(2)
7a
8
107.9(8)
97.8(1)
9
N(1)−Th-Se(1) 77.1(1)
N-Th-N 74.7(2)
N-Th-O 82.8(3)
10
11
2.892(11)
134.4(3)
a
b
c
Cp = cyclopentadienyl ring. Average value. Range value.
3639
DOI: 10.1021/acs.organomet.5b00454
Organometallics 2015, 34, 3637−3647

Organometallics
Article
spectroscopy, suggesting that diamide 5 is more stable than
diamide 6. For example, at 100 °C, 40% of 6 converts to 1, and
the equilibrium constant of the reaction is 0.27 according to the
equation Ke = ([1][Ph2NH])/([6]). Furthermore, diamide 6
can be converted to diamide 5 by reaction with p-toluidine at
70 °C (Scheme 1), again supporting the notion that 5 is more
stable than 6. Overall, these results imply that the formation of
an actinide-imido metallocene starting from the corresponding
diamide derivatives by amine elimination strongly depends on
the substituents on the amide group.3w,9
Scheme 3
The molecular structure of [η5-1,2,4-(Me3C)3C5H2]2Th-
(NH-p-tolyl)(NPh2) (6) is depicted in Figure 5. The
isomerized to only one isomer, and no degradation occurs
when the mixture is heated at 100 °C for 1 week.
The cyclopentadienyl rings in [η5-1,2,4-(Me3C)3C5H2]2Th-
(H)[N(p-tolyl)B(C8H14)] (7a) adopt a nearly eclipsed arrange-
ment (Figure 6). The average Th−C(ring) distance is 2.853(3)
Figure 5. Molecular structure of 6 (thermal ellipsoids drawn at the
35% probability level).
orientation of the cyclopentadienyl rings is nearly eclipsed,
and the two amido-groups (NH-p-tolyl and NPh2) are oriented
on either side of the eclipsed Me3C-groups. The N−Th−N
angle is 91.2(2)°, identical to that (91.2(1)°) found in [η5-
1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)2 (5).9 However, the Th−
N(1) distance (2.418(5) Å) is longer than that of Th−N(2)
(2.266(4) Å) and the average Th−N distance (2.283(3) Å) of
5,9 which can presumably be attributed to the increased steric
bulk of the Ph2N group and which also contributes to the
decreased stability of diamide 6 and the facile release of the
Ph2N group.
Figure 6. Molecular structure of 7a (thermal ellipsoids drawn at the
35% probability level).
Å, and the Cp(cent)-Th-Cp(cent) angle is 132.9(1)°. Complex
7a represents the first example of B−H bond activation induced
by an actinide imido complex. The Th−N distance is 2.421(2)
Å, which is comparable to those found in [η5-1,2,4-
(Me3C)3C5H2]2Th(H)[N(p-tolyl)SiH2Ph)] (2.387(2) Å),11
[η5-1,2,4-(Me3C)3C5H2]2Th[(bipy)(SCPh2)] (2.435(1) Å),15
[η5-1,2,4-(Me3C)3C5H2]2Th[η2-C,N-{CH2SiMe2NC(
CHPh)Ph}] (2.365(2) Å),12 (η5-C5Me5)2Th[N(N
CHSiMe3)(C4Ph4)] (2.298(3) Å),19 [η5-1,2,4-(Me3C)3C5H2]2-
Th(bipy) (2.325(5) and 2.363(4) Å),10 and [η5-1,3-
(Me3C)2C5H3]2Th(bipy) (2.326(7) and 2.325(7) Å).13 The
Th−H distance of 1.96(3) Å is in line with those found in [η5-
2.3. Reaction with Borane. As for the scandium imido
complexes,5k the B−H bond of borane can also be activated by
our actinide imido complex 1. For example, the reaction of
imido 1 with 1 equiv of 9-borabicyclo[3.3.1]nonane (9-BBN)
rapidly forms the amido hydrido metallocene [η5-1,2,4-
(Me3C)3C5H2]2Th(H)[N(p-tolyl)B(C8H14)] (7) in quantita-
1
tive conversion (Scheme 3). The H NMR spectrum of 7
clearly shows that there are two isomers, syn 7a and anti 7b,
present in C6D6 solution with the ratio of 1:1.1. However, in
contrast to the silane addition products,11 the 1H NMR
experiment confirms that the mixture of 7a and 7b cannot be
3640
DOI: 10.1021/acs.organomet.5b00454
Organometallics 2015, 34, 3637−3647

Organometallics
Article
1,2,4-(Me3C)3C5H2]2Th(H)[N(p-tolyl)SiH2Ph)] (2.01(3)
Å)11 and [η5-1,3-(Me3C)2C5H3]3ThH (1.99(5) Å).20
5, and 7 (Table 1). The Th−Cl distance is 2.613(3) Å, which is
similar to those found in [η5-1,2,4-(Me3C)3C5H2]2ThCl2
(2.621(1) Å),9 [η5-1,3-(Me3C)2C5H3]2ThCl2 (2.632(1) Å),9
and [η5-1,3-(Me3Si)2C5H3]2ThCl2 (2.632(2) Å).21
2.5. Reactions with Selenium and Diphenyldisele-
nium. Imido [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1)
reacts with elemental sulfur (S8) to form the [2 + 2]
cycloaddition product.9 It is therefore conceivable to propose
that elemental selenium (Se) might react with imido 1 in a
similar manner. Indeed treatment of imido 1 with 2 equiv of
selenium affords the desired cycloaddition product [η5-1,2,4-
(Me3C)3C5H2]2Th[N(p-tolyl)Se-Se] (9) (Scheme 5). How-
2.4. Reaction with Chlorosilane. DFT calculations
suggest that the activation barrier in the reaction between the
imido [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1) and chlor-
otrimethylsilane (Me3SiCl) proceeding via the [2 + 2] addition
mechanism (32.1 kcal mol−1) is energetically more favorable
than that for the SN2-type process (37.4 kcal mol−1).9 This
change in mechanism relative to the oxido metallocene [η5-
1,2,4-(Me3C)3C5H2]2ThO can be attributed to the increased
steric hindrance between the reaction partners.8 However, no
reaction occurs between the imido 1 and Me3SiCl because of
the high activation barrier (32.1 kcal mol−1).9 Therefore, in
order to reduce the activation barrier, a less bulky chlorosilane
is required. In fact, the treatment of imido 1 with 1 equiv of
PhSiH2Cl, indeed, gives the chloride metallocene [η5-1,2,4-
(Me3C)3C5H2]2Th(Cl)[N(p-tolyl)SiH2Ph] (8) in quantitative
Scheme 5
1
conversion (Scheme 4). The H NMR spectrum of 8 shows a
1:1:1 pattern for the Me3C-resonances, which is consistent with
the molecular C1-symmetry of 8.
Scheme 4
The molecular structure of [η5-1,2,4-(Me3C)3C5H2]2Th(Cl)-
[N(p-tolyl)SiH2Ph] (8) shows nearly eclipsed cyclopentadienyl
rings (Figure 7). The average Th−C(ring) distance is 2.878(3)
Å, and the Cp(cent)-Th-Cp(cent) angle is 135.9(1)°. The Th−
N distance is 2.389(2) Å, comparable to those found in 2, 3, 4,
ever, when the diselenide PhSeSePh is used, one [η5-1,2,4-
(Me3C)3C5H2]− ligand was oxidized to the dimer (2,3,5-
(Me3C)3C5H2)2, and the resulting anion PhSe− replaces one
cyclopentadienyl ring. However, the steric demand is now no
longer sufficient to prevent dimerization, and therefore, the μ-
imido-bridged complex {[η5-1,2,4-(Me3C)3C5H2]Th-
(SePh)}2[μ-N(p-tolyl)]2 (10) was isolated in 95% yield
(Scheme 5).
The molecular structure of [η5-1,2,4-(Me3C)3C5H2]2Th[N-
(p-tolyl)Se-Se] (9) is shown in Figure 8. The orientation of the
cyclopentadienyl rings adopt a nearly eclipsed conformation,
and the average Th−C(ring) distance is 2.869(5) Å, and the
Cp(cent)-Th-Cp(cent) angle is 133.8(3)°. Complex 9
represents the first example of elemental selenium addition to
an actinide imido complex. The Th−N distance is 2.322(5) Å,
comparable to those found in 2, 3, 4, 5, 7, and 8 (Table 1). The
average Th−Se distance is 2.934(1) Å, which is in line with that
found in [η5-1,3-(Me3C)2C5H3]2Th(SePh)2 (2.877(1) Å).13
The centrosymmetric molecular structure of {[η5-1,2,4-
(Me3C)3C5H2]Th(SePh)}2[μ-N(p-tolyl)]2 (10) is depicted in
Figure 9; and the Th4+ ion features a distorted-tetrahedral
coordination environment with an average Th−C(Cp) distance
of 2.851(5) Å. The Th−N distance of 2.170(5) Å is shorter
than those in 2, 3, 4, 6, 7, 8, and 9 (Table 1). The separation of
the two Th4+ cations (3.630(1) Å) in the dimer is in the range
previously observed for {[η5-1,2,4-(Me3C)3C5H2]2Th}2(μ-O)2
Figure 7. Molecular structure of 8 (thermal ellipsoids drawn at the
35% probability level).
3641
DOI: 10.1021/acs.organomet.5b00454
Organometallics 2015, 34, 3637−3647

Organometallics
Article
Scheme 6
addition, which is a consequence of the polarized actinide imido
bond An+-NR−;11 alternatively, this reaction could also be
explained by a [4 + 2] cycloaddition reaction.
The solid state molecular structure of [η5-1,2,4-(Me3C)3-
C5H2]2Th[N(p-tolyl)CH2C(Me)C(OMe)O] (11) is de-
picted in Figure 10. The Th4+ ion features a distorted-
Figure 8. Molecular structure of 9 (thermal ellipsoids drawn at the
35% probability level).
Figure 9. Molecular structure of 10 (thermal ellipsoids drawn at the
Figure 10. Molecular structure of 11 (thermal ellipsoids drawn at the
35% probability level).
35% probability level).
tetrahedral ligand environment with two η5-bound Cp-ring and
one σ-coordinate nitrogen atom and one oxygen atom with the
average Th−C(Cp) distance of 2.892(11) Å and an angle
Cp(cent)-Th-Cp(cent) of 134.4(3)°. The Th−N distance
(2.323(9) Å) is close to those found in 2, 3, 4, 6, 7, 8, and 9
(Table 1). The Th−O distance (2.197(9) Å) may be compared
to those found in [η5-1,2,4-(Me3C)3C5H2]2Th[O2CPh2]
(2.202(3) Å),8 [η5-1,2,4-(Me3C)3C5H2]2Th[(OCPh2)2]
(2.182(2) Å),17 and [η5-1,2,4-(Me3C)3C5H2]2Th[C(Ph)
CHPh][O−C(CH2)NMe2] (2.198(4) Å).22
(3.546(1) Å),8 and [{[η5-1,2,4-(Me3C)3C5H2]Th(N3)2}2{μ-
N(p-tolyl)}2][(n-C4H9)4N]2 (3.697(1) Å).12 The Th−Se
distance of 2.918(1) Å is close to the average distances found
in 9 (2.934(1) Å) and [η5-1,3-(Me3C)2C5H3]2Th(SePh)2
(2.877(1) Å).13
2.6. Reaction with α,β-Unsaturated Reagent. Imido
complex [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1) reacts
with unsaturated reagents such as CS2, alkyne, and nitrile to
form [2 + 2] cycloaddition products.8,9 We were then curious
to explore the reactivity of 1 with the CC−CO
functionality of α,β-unsaturated ester, for which a similar
cycloaddition reaction may occur. However, treatment of imido
1 with 1 equiv of methyl methacrylate (MMA) does not afford
the [2 + 2] cycloaddition product, but an amido enolyl complex
[η5-1,2,4-(Me3C)3C5H2]2Th[N(p-tolyl)CH2C(Me)C-
(OMe)O] (11) is isolated in good yield (Scheme 6). The
formation of 11 can be rationalized on the basis of a Michael
3. CONCLUSIONS
In conclusion, the base-free thorium imido metallocene, [η5-
1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1), activates the C−H
bond of pyridine derivatives, N−H bond of amines, B−H bond
of boranes, and Si−Cl bond of chlorosilane in a 1,2-addition
reaction, forming amido pyridyl, diamido, amido hydrido, and
3642
DOI: 10.1021/acs.organomet.5b00454
Organometallics 2015, 34, 3637−3647

Organometallics
Article
tube charged with [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1; 16
amido chloride compounds, respectively. However, the reaction
is reversible for amines, consistent with the observation that
actinide diamide complexes are efficient catalysts for the
hydroamination of alkynes and the fact that these imido
complexes can serve as intermediates in these reactions. In
contrast, the reactions are irreversible for pyridine, borane, and
chlorosilane. In addition, imido complex 1 is also capable of
activating elemental selenium and its organic derivatives such as
PhSeSePh in a redox process, yielding the cyclic amido selenido
complex [η5-1,2,4-(Me3C)3C5H2]2Th[N(p-tolyl)Se-Se] (9)
and dimeric imido selenido complex {[η5-1,2,4-(Me3C)3C5H2]-
Th(SePh)}2[μ-N(p-tolyl)]2 (10). Furthermore, with α,β-
unsaturated reagents such as methyl methacrylate (MMA)
imido complex 1 undergoes a Michael addition reaction or a [4
+ 2] cycloaddition reaction to form the amido enolyl
compound [η5-1,2,4-(Me3C)3C5H2]2Th[N(p-tolyl)CH2C-
(Me)C(OMe)O] (11). Additional investigations of these
imido, amido hydrido, and amido pyridyl complexes in the
context of small molecule activation and in organic synthesis
are still ongoing and will be reported in due course.
mg, 0.02 mmol) and C6D6 (0.2 mL). The resonances due to 2 were
1
observed by H NMR spectroscopy (100% conversion).
4.3. Preparation of [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)(κ2-
C,O-C5H4NO) (3). 4.3.1. Method A. This compound was prepared as
colorless crystals from the reaction of [η5-1,2,4-(Me3C)3C5H2]2Th
N(p-tolyl) (1; 500 mg, 0.622 mmol) and pyridine N-oxide (59 mg,
0.622 mmol) in toluene (15 mL) and recrystallization from an n-
hexane solution by a procedure similar to that in the synthesis of 2.
1
Yield: 475 mg (85%). M.p.: 138−140 °C (dec.). H NMR (C6D6): δ
7.99 (d, J = 6.4 Hz, 1H, py), 7.20 (d, J = 6.4 Hz, 1H, py), 7.17 (d, J =
8.0 Hz, 2H, phenyl), 7.06 (d, J = 8.0 Hz, 2H, phenyl), 6.69 (t, J = 6.4
Hz, 1H, py), 6.62 (d, J = 3.2 Hz, 2H, ring CH), 6.24 (t, J = 6.4 Hz, 1H,
py), 6.21 (d, J = 3.2 Hz, 2H, ring CH), 4.37 (s, 1H, NH), 2.30 (s, 3H,
tolylCH3), 1.49 (s, 18H, (CH3)3C), 1.43 (s, 18H, (CH3)3C), 1.32 (s,
18H, (CH3)3C). 13C{1H} NMR (C6D6): δ 222.3 (ThC), 157.0 (aryl
C), 142.4 (aryl C), 142.0 (aryl C), 140.8 (aryl C), 138.5 (aryl C), 134.5
(aryl C), 129.5 (aryl C), 128.3 (aryl C), 124.5 (ring C), 121.9 (ring C),
118.9 (ring C), 115.0 (ring C), 114.4 (ring C), 35.0 (C(CH3)3), 34.7
(C(CH3)3), 34.3 (C(CH3)3), 34.2 (C(CH3)3), 33.9 (C(CH3)3), 33.1
(C(CH3)3), 20.8 (tolylCH3). IR (KBr, cm−1): ν 2961 (s), 1603 (m),
1501 (m), 1448 (m), 1384 (s), 1260 (s), 1091 (s), 1019 (s), 799 (s).
Anal. Calcd for C46H70N2OTh: C, 61.45; H, 7.85; N, 3.12. Found: C,
61.42; H, 7.88; N, 3.03.
4. EXPERIMENTAL SECTION
4.3.2. Method B. 4.3.2.1. NMR Scale. A C6D6 (0.3 mL) solution of
pyridine N-oxide (1.9 mg; 0.02 mmol) was slowly added to a J. Young
NMR tube charged with [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1;
16 mg, 0.02 mmol) and C6D6 (0.2 mL). The resonances due to 3 were
4.1. General Methods. All reactions and product manipulations
were carried out under an atmosphere of dry dinitrogen with rigid
exclusion of air and moisture using standard Schlenk or cannula
techniques, or in a glovebox. All organic solvents were freshly distilled
from sodium benzophenone ketyl immediately prior to use. PhSiH2Cl
was distilled under nitrogen prior to use. Ph2NH and p-MeC6H4NH2
were purified by sublimation. [η5-1,2,4-(Me3C)3C5H2]2ThN(p-
tolyl) (1)8,9 was prepared according to literature methods. All other
chemicals were purchased from Aldrich Chemical Co. and Beijing
Chemical Co. and used as received unless otherwise noted. Infrared
spectra were obtained from KBr pellets on an Avatar 360 Fourier
transform spectrometer. 1H, 13C, and 11B NMR spectra were recorded
on a Bruker AV 400 spectrometer at 400, 100, and 128 MHz,
respectively. All chemical shifts are reported in δ units with reference
to the residual protons of the deuterated solvents for proton and
carbon chemical shifts, but they also served as the internal standard in
our NMR investigations. Melting points were measured on an X-6
melting point apparatus and were uncorrected. Elemental analyses
were performed on a Vario EL elemental analyzer.
1
observed by H NMR spectroscopy (100% conversion).
4.4. Preparation of [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)(κ2-
C,O-2-MeC5H3NO) (4). 4.4.1. Method A. This compound was
prepared as colorless crystals from the reaction of [η5-1,2,4-
(Me3C)3C5H2]2ThN(p-tolyl) (1; 500 mg, 0.622 mmol) and 2-
methylpyridine N-oxide (68 mg, 0.622 mmol) in toluene (15 mL) and
recrystallization from an n-hexane solution by a procedure similar to
that in the synthesis of 2. Yield: 471 mg (83%). M.p.: 148−150 °C
1
(dec.). H NMR (C6D6): δ 7.99 (d, J = 6.0 Hz, 1H, py), 7.15 (d, J =
8.0 Hz, 2H, phenyl), 7.10 (d, J = 8.0 Hz, 2H, phenyl), 6.74 (t, J = 6.0
Hz, 1H, py), 6.64 (s, 2H, ring CH), 6.32 (d, J = 6.0 Hz, 1H, py), 6.22
(s, 2H, ring CH), 4.16 (s, 1H, NH), 2.32 (s, 3H, tolylCH3), 2.22 (s,
3H, pyCH3), 1.50 (s, 18H, (CH3)3C), 1.44 (s, 18H, (CH3)3C), 1.30
(s, 18H, (CH3)3C). 13C{1H} NMR (C6D6): δ 211.2 (ThC), 157.2
(aryl C), 144.5 (aryl C), 142.4 (aryl C), 141.8 (aryl C), 140.4 (aryl C),
138.1 (aryl C), 129.5 (aryl C), 124.3 (aryl C), 122.6 (ring C), 118.8
(ring C), 115.7 (ring C), 115.1 (ring C), 114.5 (ring C), 35.0
(C(CH3)3), 34.6 (C(CH3)3), 34.3 (C(CH3)3), 34.2 (C(CH3)3), 33.9
(C(CH3)3), 33.2 (C(CH3)3), 20.8 (tolylCH3), 16.3 (pyCH3). IR (KBr,
cm−1): ν 2961 (s), 1605 (m), 1502 (m), 1451 (m), 1384 (s), 1260 (s),
1091 (s), 1019 (s), 799 (s). Anal. Calcd for C47H72N2OTh: C, 61.82;
H, 7.95; N, 3.07. Found: C, 61.72; H, 7.98; N, 3.05.
4.2. Preparation of [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)(η2-
C,N-C5H4N) (2). 4.2.1. Method A. A toluene (5 mL) solution of
pyridine (50 mg, 0.622 mmol) was added to a toluene (10 mL)
solution of [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1; 500 mg,
0.622 mmol). After this solution was stirred at room temperature for 1
h, the solvent was removed. The residue was extracted with n-hexane
(10 mL × 2) and filtered. The volume of the filtrate was reduced to ca.
2 mL, and yellow crystals 2 were isolated when this solution stood at
room temperature for 2 days. Yield: 439 mg (80%). M.p.: 200−202 °C
(dec). 1H NMR (C6D6): δ 8.39 (d, J = 6.0 Hz, 1H, py), 8.01 (d, J = 7.2
Hz, 1H, py), 7.19 (d, J = 8.0 Hz, 2H, phenyl), 7.07 (t, J = 7.2 Hz, 1H,
py), 6.93 (d, J = 8.0 Hz, 2H, phenyl), 6.62 (d, J = 6.0 Hz, 1H, py), 6.56
(d, J = 2.9 Hz, 2H, ring CH), 6.16 (d, J = 2.9 Hz, 2H, ring CH), 4.86
(s, 1H, NH), 2.34 (s, 3H, tolylCH3), 1.50 (s, 18H, (CH3)3C), 1.30 (s,
18H, (CH3)3C), 1.18 (s, 18H, (CH3)3C). 13C{1H} NMR (C6D6): δ
236.7 (ThC), 156.4 (aryl C), 145.9 (aryl C), 142.0 (aryl C), 141.3 (aryl
C), 141.2 (aryl C), 135.7 (aryl C), 135.6 (aryl C), 129.6 (aryl C), 124.1
(ring C), 124.0 (ring C), 118.4 (ring C), 115.3 (ring C), 114.2 (ring
C), 34.8 (C(CH3)3), 34.5 (C(CH3)3), 34.1 (C(CH3)3), 33.9
(C(CH3)3), 33.4 (C(CH3)3), 33.1 (C(CH3)3), 20.8 (tolylCH3). IR
(KBr, cm−1): ν 2958 (s), 2868 (s), 1622 (m), 1516 (m), 1460 (s),
1386 (s), 1361 (s), 1259 (s), 1093 (s), 1022 (s), 802 (s). Anal. Calcd
for C46H70N2Th: C,62.56; H,7.99; N,3.17. Found: C, 62.42; H, 7.98;
N, 3.03.
4.4.2. Method B. 4.4.2.1. NMR Scale. A C6D6 (0.3 mL) solution of
2-methylpyridine N-oxide (2.2 mg; 0.02 mmol) was slowly added to a
J. Young NMR tube charged with [η5-1,2,4-(Me3C)3C5H2]2ThN(p-
tolyl) (1; 16 mg, 0.02 mmol) and C6D6 (0.2 mL). The resonances due
1
to 4 were observed by H NMR spectroscopy (100% conversion).
4.5. Reaction of [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1)
with p-Toluidine. NMR Scale. To a J. Young NMR tube charged
with [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1; 16 mg, 0.02 mmol)
and C6D6 (0.5 mL), p-toluidine (2.2 mg, 0.02 mmol) was added. The
resonances due to [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)2 (5) (1H
NMR (C6D6): δ 7.06 (d, J = 8.0 Hz, 4H, aryl), 6.84 (d, J = 8.0 Hz, 4H,
aryl), 6.58 (s, 4H, ring CH), 5.07 (s, 2H, NH), 2.22 (s, 6H, tolylCH3),
1.42 (s, 36H, (CH3)3C), 1.41 (s, 18H, (CH3)3C))9 were observed by
1H NMR spectroscopy (100% conversion).
4.6. Preparation of [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)-
(NPh2) (6). 4.6.1. Method A. This compound was prepared as
colorless crystals from the reaction of [η5-1,2,4-(Me3C)3C5H2]2Th
N(p-tolyl) (1; 500 mg, 0.622 mmol) and Ph2NH (106 mg, 0.622
mmol) in toluene (15 mL) and recrystallization from an n-hexane
solution by a procedure similar to that in the synthesis of 2. Yield: 521
4.2.2. Method B. 4.2.2.1. NMR Scale. A C6D6 (0.3 mL) solution of
pyridine (1.6 mg; 0.02 mmol) was slowly added to a J. Young NMR
3643
DOI: 10.1021/acs.organomet.5b00454
Organometallics 2015, 34, 3637−3647

Organometallics
Article
1
mg (86%). M.p.: 82−84 °C (dec.). H NMR (C6D6): δ 7.26 (m, 8H,
phenyl), 7.12 (m, 2H, phenyl), 7.08 (m, 2H, phenyl), 6.96 (m, 2H,
phenyl), 6.85 (d, J = 3.2 Hz, 2H, ring CH), 6.66 (d, J = 3.2 Hz, 2H,
ring CH), 5.73 (s, 1H, NH), 2.26 (s, 3H, tolylCH3), 1.48 (s, 18H,
(CH3)3C), 1.37 (s, 18H, (CH3)3C), 1.15 (s, 18H, (CH3)3C). 13C{1H}
NMR (C6D6): δ 154.8 (phenyl C), 154.4 (phenyl C), 147.4 (phenyl
C), 143.9 (phenyl C), 129.7 (phenyl C), 129.3 (phenyl C), 128.3
(phenyl C), 120.9 (phenyl C), 119.5 (ring C), 118.2 (ring C), 118.0
(ring C), 117.8 (ring C), 117.2 (ring C), 35.3 (C(CH3)3), 35.2
(C(CH3)3), 35.0 (C(CH3)3), 34.2 (C(CH3)3), 33.9 (C(CH3)3), 32.8
(C(CH3)3), 20.5 (tolylCH3); four phenyl C resonaces overlapped. IR
(KBr, cm−1): ν 2961 (s), 1583 (m), 1497 (m), 1259 (s), 1090 (s),
1019 (s), 799 (s). Anal. Calcd for C53H76N2Th: C, 65.41; H, 7.87; N,
2.88. Found: C, 65.42; H, 7.68; N, 3.03.
other resonances in 7a and 7b accordingly. The ratio of 7a/7b is ca.
1:1.1. The mixture of 7a and 7b could not be isomerized to one
isomer, and the spectrum did not show any change even after heating
at 100 °C for 1 week in C6D6, which was monitored by H NMR
spectroscopy in a J. Young NMR tube.
1
4.8.2. Method B. NMR Scale. To a J. Young NMR tube charged
with [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1; 16 mg, 0.02 mmol)
and C6D6 (0.5 mL), an excess of 9-BBN (2.5 mg, 0.02 mmol) was
1
added. The resonances due to 7 (7a and 7b) were observed by H
NMR spectroscopy (100% conversion in 10 min).
4.9. Preparation of [η5-1,2,4-(Me3C)3C5H2]2Th(Cl)[N(p-tolyl)-
SiH2Ph] (8). 4.9.1. Method A. This compound was prepared as
colorless crystals from the reaction of [η5-1,2,4-(Me3C)3C5H2]2Th
N(p-tolyl) (1; 500 mg, 0.622 mmol) and PhSiH2Cl (90 mg, 0.622
mmol) in toluene (15 mL) and recrystallization from an n-hexane
solution by a procedure similar to that in the synthesis of 2. Yield: 542
4.6.2. Method B. NMR Scale. To a J. Young NMR tube charged
with [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1; 16 mg, 0.02 mmol)
and C6D6 (0.5 mL), Ph2NH (3.4 mg, 0.02 mmol) was added. The
resonances due to 6 were observed by H NMR spectroscopy (100%
conversion in 10 min). When the NMR sample was heated over 80 °C,
an equilibrium between diamide 6 and imido 1 was observed by H
1
mg (92%). M.p.: 142−144 °C (dec.). H NMR (C6D6): δ 7.60 (m,
1
2H, phenyl), 7.30 (d, J = 8.0 Hz, 2H, phenyl), 7.08 (m, 3H, phenyl),
6.95 (d, J = 8.0 Hz, 2H, phenyl), 6.58 (d, J = 3.4 Hz, 2H, ring CH),
6.50 (d, J = 3.4 Hz, 2H, ring CH), 5.59 (s, 2H, SiH2), 2.11 (s, 3H,
tolylCH3), 1.61 (s, 18H, (CH3)3C), 1.41 (s, 18H, (CH3)3C), 1.40 (s,
18H, (CH3)3C). 13C{1H} NMR (C6D6): δ 147.6 (phenyl C), 145.5
(phenyl C), 135.7 (phenyl C), 132.6 (phenyl C), 130.2 (phenyl C),
130.1 (phenyl C), 129.5 (phenyl C), 129.1 (phenyl C), 125.6 (ring C),
125.4 (ring C), 119.6 (ring C), 119.2 (ring C), 117.6 (ring C), 35.3
(C(CH3)3), 35.2 (C(CH3)3), 35.0 (C(CH3)3), 34.4 (C(CH3)3), 34.0
(C(CH3)3), 32.7 (C(CH3)3), 20.4 (tolylCH3). IR (KBr, cm−1): ν 2961
(s), 2125 (w), 1498 (m), 1383 (s), 1260 (s), 1018 (s), 1018 (s), 799
(s). Anal. Calcd for C47H72NClSiTh: C, 59.63; H, 7.67; N, 1.48.
Found: C, 59.52; H, 7.82; N, 1.43.
1
NMR spectroscopy; however, we also observed some additional
resonances attributable to small amounts of unidentified (decom-
posed) complexes, suggesting that complex 6 exhibits moderate
stability above 80 °C precluding a closer evaluation of this equilibrium
at variable temperatures.
4.7. Reaction of [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)(NPh2)
(6) with p-Toluidine. 4.7.1. NMR Scale. To a J. Young NMR tube
charged with [η5-1,2,4-(Me3C)3C5H2]2Th(NH-p-tolyl)(NPh2) (6; 20
mg, 0.02 mmol) and C6D6 (0.5 mL), p-toluidine (2.2 mg, 0.02 mmol)
was added. The mixture was kept at 70 °C for 1 day, and resonances
due to 5 along with those of Ph2NH (1H NMR (C6D6): δ 7.18 (m,
4.9.2. Method B. 4.9.2.1. NMR Scale. To a J. Young NMR tube
charged with [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1; 16 mg,
0.02 mmol) and C6D6 (0.5 mL), an excess of PhSiH2Cl was added.
1
4H, Ph), 6.84 (m, 6H, Ph), 4.98 (s, 1H, NH)) were observed by H
NMR spectroscopy (100% conversion).
4.8. Preparation of [η5-1,2,4-(Me3C)3C5H2]2Th(H)[N(p-tolyl)B-
(C8H14)] (7). 4.8.1. Method A. This compound was prepared as
colorless crystals from the reaction of [η5-1,2,4-(Me3C)3C5H2]2Th
N(p-tolyl) (1; 500 mg, 0.622 mmol) and 9-BBN (76 mg, 0.622 mmol)
in toluene (15 mL) and recrystallization from an n-hexane solution by
a procedure similar to that in the synthesis of 2. Yield: 426 mg (74%).
M.p.: 140−142 °C (dec.). The NMR spectrum showed that there were
1
The resonances due to 8 were observed by H NMR spectroscopy
(100% conversion in 10 min).
4.10. Preparation of [η5-1,2,4-(Me3C)3C5H2]2Th[N(p-tolyl)Se-
Se] (9). 4.10.1. Method A. This compound was prepared as orange
crystals from the reaction of [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl)
(1; 500 mg, 0.622 mmol) and selenium (98 mg, 1.244 mmol) in
toluene (15 mL) and recrystallization from an n-hexane solution by a
procedure similar to that in the synthesis of 2. Yield: 478 mg (80%).
M.p.: 160−162 °C (dec). 1H NMR (C6D6): δ 7.37 (d, J = 8.2 Hz, 2H,
phenyl), 7.01 (d, J = 8.2 Hz, 2H, phenyl), 6.63 (br s, 4H, ring CH),
2.19 (s, 3H, tolylCH3), 1.55 (s, 18H, (CH3)3C), 1.37 (s, 36H,
(CH3)3C). 13C{1H} NMR (C6D6): δ 155.9 (phenyl C), 129.7 (phenyl
C), 129.2 (phenyl C), 129.0 (phenyl C), 122.0 (ring C), 119.0 (ring
C), 115.9 (ring C), 35.2 (C(CH3)3), 34.6 (C(CH3)3), 34.5 (C(CH3)3),
32.8 (C(CH3)3), 20.5 (tolylCH3). IR (KBr, cm−1): ν 2958 (s), 1604
(m), 1496 (s), 1360 (s), 1238 (s), 1107 (s), 1020 (s), 808 (s). Anal.
Calcd for C41H65NSe2Th: C,51.19; H,6.81; N,1.46. Found: C, 51.17;
H, 6.78; N, 1.53.
1
two isomers in C6D6 solution. Syn isomer 7a: H NMR (C6D6): δ
19.28 (s, 1H, ThH), 7.87 (s, 2H, phenyl), 6.96 (d, J = 7.5 Hz, 2H,
phenyl), 6.08 (m, 2H, NBCH), 5.99 (d, J = 3.0 Hz, 2H, ring CH), 5.92
(d, J = 3.0 Hz, 2H, ring CH), 2.38−1.73 (m, 12H, CH2), 2.20 (s, 3H,
tolylCH3), 1.61 (s, 18H, (CH3)3C), 1.57 (s, 18H, (CH3)3C), 1.41 (s,
18H, (CH3)3C). 13C{1H} NMR (C6D6): δ 139.3 (phenyl C), 133.4
(phenyl C), 129.4 (phenyl C), 125.7 (phenyl C), 122.9 (ring C), 117.2
(ring C), 115.2 (ring C), 114.8 (ring C), 112.3 (ring C), 35.2
(C(CH3)3), 35.1 (C(CH3)3), 34.8 (C(CH3)3), 34.3 (C(CH3)3), 33.6
(C(CH3)3), 32.2 (C(CH3)3), 27.0 (CH), 24.1 (CH2), 23.8 (CH2), 23.6
(CH2), 20.5 (tolylCH3). 11B NMR (C6D6): δ −2.95. Anti isomer 7b:
1H NMR (C6D6): δ 16.82 (s, 1H, ThH), 7.32 (d, J = 8.0 Hz, 2H,
phenyl), 7.02 (d, J = 8.0 Hz, 2H, phenyl), 6.48 (m, 2H, NBCH), 6.34
(d, J = 3.3 Hz, 2H, ring CH), 6.11 (d, J = 3.3 Hz, 2H, ring CH), 2.38−
1.73 (m, 12H, CH2), 2.35 (s, 3H, tolylCH3), 1.51 (s, 18H, (CH3)3C),
1.38 (s, 18H, (CH3)3C), 1.31 (s, 18H, (CH3)3C). 13C{1H} NMR
(C6D6): δ 139.3 (phenyl C), 133.4 (phenyl C), 129.4 (phenyl C),
125.7 (phenyl C), 122.9 (ring C), 117.2 (ring C), 115.2 (ring C), 114.8
(ring C), 112.3 (ring C), 35.2 (C(CH3)3), 35.1 (C(CH3)3), 34.8
(C(CH3)3), 34.3 (C(CH3)3), 33.6 (C(CH3)3), 32.2 (C(CH3)3), 27.0
(CH), 24.1 (CH2), 23.8 (CH2), 23.6 (CH2), 20.5 (tolylCH3). 11B
NMR (C6D6): δ −2.95. IR (KBr, cm−1): ν 2962 (s), 1448 (m), 1384
(s), 1260 (s), 1090 (s), 1019 (s), 798 (s). Anal. Calcd for
C49H80NBTh: C, 63.55; H, 8.71; N, 1.51. Found: C, 63.52; H, 8.82;
N, 1.43.
4.10.2. Method B. NMR Scale. To a J. Young NMR tube charged
with [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1; 16 mg, 0.02 mmol)
and C6D6 (0.5 mL), selenium (3.2 mg, 0.04 mmol) was added. The
NMR sample was maintained at room temperature for 2 days, and the
1
resonances due to 9 were observed by H NMR spectroscopy (100%
conversion).
4.11. Preparation of {[η5-1,2,4-(Me3C)3C5H2]Th(SePh)}2[μ-N(p-
tolyl)]2 (10). A toluene (5 mL) solution of PhSeSePh (194 mg, 0.622
mmol) was added to a toluene (10 mL) solution of [η5-1,2,4-
(Me3C)3C5H2]2ThN(p-tolyl) (1; 500 mg, 0.622 mmol). After this
solution was heated at 70 °C overnight without stirring, colorless
crystals were isolated from the solution, which were identified as 10 by
X-ray diffraction analysis. Yield: 429 mg (95%). M.p.: 230−232 °C
(dec.). IR (KBr, cm−1): ν 2961 (s), 1573 (w), 1486 (s), 1384 (s), 1259
(s), 1242 (s), 1091 (s), 1019 (s), 876 (s), 799 (s). Anal. Calcd for
C60H82N2Se2Th2: C, 49.59; H, 5.69; N, 1.93. Found: C, 49.52; H, 5.68;
N, 2.01. This compound was insoluble in deuterated solvents such as
pyrdine, THF, toluene, CDCl3, and CD2Cl2, which made the
characterization by NMR spectroscopy infeasible.
Note that the NMR spectra of 7a and 7b could not be assigned
unambiguously. However, in the similar complex [η5-1,2,4-(Me3C)3-
C5H2]2Th(H)[N(p-tolyl)SiH2Ph] the resonances of Th-H at δ =
18.07 and 16.93 ppm could be attributed to the syn and anti isomers,
respectively,11 and we therefore assigned the Th−H groups and the
3644
DOI: 10.1021/acs.organomet.5b00454
Organometallics 2015, 34, 3637−3647

Organometallics
Article
The solvent of the filtrate was removed. The residue was extracted
with n-hexane (10 mL × 2) and filtered. The volume of the filtrate was
reduced to ca. 2 mL, colorless crystals, which were identified as (2,3,5-
(Me3C)3C5H2)2 (1H NMR (C6D6): δ 6.48 (s, 4H, CH), 1.38 (s, 36H,
(CH3)3C), 1.01 (s, 18H, (CH3)3C))3v by 1H NMR spectroscopy, were
isolated in 70% yield (101 mg) when this solution stood at −20 °C for
2 days.
ASSOCIATED CONTENT
* Supporting Information
■
S
Structures of stationary points along the reaction path; crystal
parameters for compounds 2−4 and 6−11; Cartesian
coordinates of all stationary points optimized at the
B3PW91-PCM+D3 level, in XYZ format; and X-ray crystallo-
graphic data, in CIF format, for compounds 2−4 and 6−11.
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.organo-
met.5b00454.
4.12. Reaction of [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1)
with PhSeSePh. NMR Scale. To a J. Young NMR tube charged with
[η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1; 16 mg, 0.02 mmol) and
C6D6 (0.5 mL), PhSeSePh (6.2 mg, 0.02 mmol) was added. The
mixture was kept at 70 °C overnight, a colorless precipitate was
observed (formation of compound 10). In addition, the resonances
due to 1 disappeared, and only resonances attributed to (2,3,5-
(Me3C)3C5H2)2 were observed by 1H NMR spectroscopy (100%
conversion).
AUTHOR INFORMATION
Corresponding Authors
*(G.Z.) E-mail: gzi@bnu.edu.cn.
*(D.-C.F.) E-mail: dcfang@bnu.edu.cn.
*(M.D.W.) E-mail: mwalter@tu-bs.de.
■
4.13. Preparation of [η5-1,2,4-(Me3C)3C5H2]2Th[N(p-tolyl)-
CH2C(Me)C(OMe)O] (11). 4.13.1. Method A. This compound
was prepared as colorless crystals from the reaction of [η5-1,2,4-
(Me3C)3C5H2]2ThN(p-tolyl) (1; 500 mg, 0.622 mmol) and MMA
(90 mg, 0.622 mmol) in toluene (15 mL) and recrystallization from an
n-hexane solution by a procedure similar to that in the synthesis of 2.
Author Contributions
§E.Z. and W.R. contributed equally to this work.
Notes
1
Yield: 449 mg (80%). M.p.: 226−228 °C (dec). H NMR (C6D6): δ
The authors declare no competing financial interest.
7.20 (d, J = 8.0 Hz, 2H, phenyl), 6.83 (d, J = 8.0 Hz, 2H, phenyl), 6.55
(d, J = 3.4 Hz, 2H, ring CH), 6.44 (d, J = 3.4 Hz, 2H, ring CH), 4.15
(s, 2H, CH2), 3.62 (s, 3H, OCH3), 2.26 (s, 3H, tolylCH3), 2.09 (s, 3H,
CCCH3), 1.53 (s, 18H, (CH3)3C), 1.41 (s, 18H, (CH3)3C), 1.33 (s,
18H, (CH3)3C). 13C{1H} NMR (C6D6): δ 158.6 (CCO), 153.2
(phenyl C), 144.9 (phenyl C), 144.1 (phenyl C), 144.0 (phenyl C),
130.4 (ring C), 126.9 (ring C), 118.5 (ring C), 117.3 (ring C), 115.8
(ring C), 85.5 (CCO), 55.0 (OCH3), 54.8 (NCH2), 35.1
(C(CH3)3), 34.9 (C(CH3)3), 34.7 (C(CH3)3), 34.3 (C(CH3)3), 33.8
(C(CH3)3), 32.8 (C(CH3)3), 20.7 (tolylCH3), 15.0 (CCCH3). IR
(KBr, cm−1): ν 2960 (s), 1737 (w), 1620 (m), 1521 (s), 1462 (s),
1361 (s), 1257 (s), 1093 (s), 1022 (s), 806 (s). Anal. Calcd for
C46H73NO2Th: C,61.11; H,8.14; N,1.55. Found: C, 61.12; H, 8.08; N,
1.53.
ACKNOWLEDGMENTS
■
This work was supported by the National Natural Science
Foundation of China (Grant Nos. 21472013, 21172022,
21272026, and 21373030), the Program for Changjiang
Scholars and Innovative Research Team in University, and
the Deutsche Forschungsgemeinschaft (DFG) through the
Emmy-Noether and Heisenberg programs (WA 2513/2 and
WA 2513/6, respectively).
REFERENCES
■
(1) For selected recent reviews, see: (a) Ephritikhine, M. Dalton
Trans. 2006, 2501−2516. (b) Barnea, E.; Eisen, M. S. Coord. Chem.
Rev. 2006, 250, 855−899. (c) Fox, A. R.; Bart, S. C.; Meyer, K.;
Cummins, C. C. Nature 2008, 455, 341−349. (d) Andrea, T.; Eisen,
M. S. Chem. Soc. Rev. 2008, 37, 550−567. (e) Graves, C. R.; Kiplinger,
J. L. Chem. Commun. 2009, 3831−3853. (f) Hayton, T. W. Dalton
Trans. 2010, 39, 1145−1158. (g) Arnold, P. L. Chem. Commun. 2011,
47, 9005−9010. (h) Hayton, T. W. Chem. Commun. 2013, 49, 2956−
2973. (i) Hayton, T. W. Nat. Chem. 2013, 5, 451−452. (j) Zi, G.-F.;
Zhang, Z.-B.; Xiang, L.; Wang, Q.-W. Chin. J. Org. Chem. 2006, 26,
1606−1611. (k) Ren, W.; Zhao, N.; Chen, L.; Zi, G. Youji Huaxue
2013, 33, 1121−1136. (l) Zi, G. Sci. China: Chem. 2014, 57, 1064−
1072.
(2) For selected papers on actinide nonmetallocenes containing
terminal imido groups, see: (a) Burns, C. J.; Smith, W. H.; Huffman, J.
C.; Sattelberger, A. P. J. Am. Chem. Soc. 1990, 112, 3237−3239.
(b) Brown, D. R.; Denning, R. G. Inorg. Chem. 1996, 35, 6158−6163.
(c) Roussel, P.; Boaretto, R.; Kingsley, A. J.; Alcock, N. W.; Scott, P. J.
Chem. Soc., Dalton Trans. 2002, 1423−1428. (d) Castro-Rodriguez, I.;
Olsen, K.; Gantzel, P.; Meyer, K. J. Am. Chem. Soc. 2003, 125, 4565−
4571. (e) Hayton, T. W.; Boncella, J. M.; Scott, B. L.; Palmer, P. D.;
Batista, E. R.; Hay, P. J. Science 2005, 310, 1941−1943. (f) Hayton, T.
W.; Boncella, J. M.; Scott, B. L.; Batista, E. R.; Hay, P. J. J. Am. Chem.
Soc. 2006, 128, 10549−10559. (g) Hayton, T. W.; Boncella, J. M.;
Scott, B. L.; Batista, E. R. J. Am. Chem. Soc. 2006, 128, 12622−12623.
(h) Castro-Rodriguez, I.; Nakai, H.; Meyer, K. Angew. Chem., Int. Ed.
2006, 45, 2389−2392. (i) Spencer, L. P.; Yang, P.; Scott, B. L.; Batista,
E. R.; Boncella, J. M. J. Am. Chem. Soc. 2008, 130, 2930−2931. (j) Bart,
S. C.; Anthon, C.; Heinemann, F. W.; Bill, E.; Edelstein, N. M.; Meyer,
K. J. Am. Chem. Soc. 2008, 130, 12536−12546. (k) Spencer, L. P.;
Schelter, E. J.; Yang, P.; Gdula, R. L.; Scott, B. L.; Thompson, J. D.;
Kiplinger, J. L.; Batista, E. R.; Boncella, J. M. Angew. Chem., Int. Ed.
2009, 48, 3795−3798. (l) Spencer, L. P.; Yang, P.; Scott, B. L.; Batista,
E. R.; Boncella, J. M. Inorg. Chem. 2009, 48, 2693−2700. (m) Spencer,
4.13.2. Method B. 4.13.2.1. NMR Scale. A C6D6 (0.3 mL) solution
of MMA (2.9 mg; 0.02 mmol) was slowly added to a J. Young NMR
tube charged with [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) (1; 16
mg, 0.02 mmol) and C6D6 (0.2 mL). The resonances due to 11 were
1
observed by H NMR spectroscopy (100% conversion).
4.14. X-ray Crystallography. Single-crystal X-ray diffraction
measurements were carried out on a Bruker Smart APEX II CCD
diffractometer at 100(2) K using graphite monochromated Mο Kα
radiation (λ = 0.71073 Å). An empirical absorption correction was
applied using the SADABS program.23 All structures were solved by
direct methods and refined by full-matrix least-squares on F2 using the
SHELXL-97 program package.24 The hydride atom in 7a was located
in the difference-Fourier map and refined isotropically. All other
hydrogen atoms were geometrically fixed using the riding model. The
crystal data and experimental data for 2−4 and 6−11 are summarized
in the Supporting Information (Tables S1 and S2). Selected bond
lengths and angles are listed in Table 1.
4.15. Computational Methods. All calculations were carried out
with the Gaussian 09 program (G09),25 employing the B3PW91
functional, plus a polarizable continuum model (PCM) and D326
(denoted as B3PW91-PCM+D3), with a standard 6-31G(d) basis set
for C, H, N, and O elements and Stuttgart RLC ECP from the EMSL
basis set exchange (https://bse.pnl.gov/bse/portal) for Th,27 to fully
optimize the structures of reactants, complexes, transition state,
intermediates, and products, and also to mimic the experimental
toluene-solvent conditions (dielectric constant ε = 2.379). All
stationary points were subsequently characterized by vibrational
analyses, from which their respective zero-point (vibrational) energy
(ZPE) was extracted and used in the relative energy determinations; in
addition, frequency calculations were also performed to ensure that the
reactant, complex, intermediate, product, and transition state
structures resided at minima and first order saddle points, respectively,
on their potential energy hyper surfaces.
3645
DOI: 10.1021/acs.organomet.5b00454
Organometallics 2015, 34, 3637−3647

Organometallics
Article
L. P.; Yang, P.; Scott, B. L.; Batista, E. R.; Boncella, J. M. Inorg. Chem.
2009, 48, 11615−11623. (n) Swartz, D. L., II; Spencer, L. P.; Scott, B.
L.; Odom, A. L.; Boncella, J. M. Dalton Trans. 2010, 39, 6841−6846.
(o) Seaman, L. A.; Fortier, S.; Wu, G.; Hayton, T. W. Inorg. Chem.
2011, 50, 636−646. (p) Jilek, R. E.; Spencer, L. P.; Kuiper, D. L.;
Scott, B. L.; Williams, U. J.; Kikkawa, J. M.; Schelter, E. J.; Boncella, J.
M. Inorg. Chem. 2011, 50, 4235−4237. (q) Matson, E. M.; Fanwick, P.
E.; Bart, S. C. Eur. J. Inorg. Chem. 2012, 2012, 5471−5478. (r) Matson,
E. M.; Crestani, M. G.; Fanwick, P. E.; Bart, S. C. Dalton Trans. 2012,
41, 7952−7958. (s) Lam, O. P.; Franke, S. M.; Nakai, H.; Heinemann,
F. W.; Hieringer, W.; Meyer, K. Inorg. Chem. 2012, 51, 6190−6199.
20096. (h) Chu, T.; Piers, W. E.; Dutton, J. L.; Parvez, M.
Organometallics 2013, 32, 1159−1165. (i) Chu, J.; Lu, E.; Chen, Y.;
Leng, X. Organometallics 2013, 32, 1137−1140. (j) Rong, W.; Cheng,
J.; Mou, Z.; Xie, H.; Cui, D. Organometallics 2013, 32, 5523−5529.
(k) Chu, J.; Han, X.; Kefalidis, C. E.; Zhou, J.; Maron, L.; Leng, X.;
Chen, Y. J. Am. Chem. Soc. 2014, 136, 10894−10897. (l) Chu, J.;
Kefalidis, C. E.; Maron, L.; Leng, X.; Chen, Y. J. Am. Chem. Soc. 2013,
135, 8165−8168.
(6) Selected papers on group 4 imido complexes: (a) Walsh, P. J.;
Hollander, F. J.; Bergman, R. G. J. Am. Chem. Soc. 1988, 110, 8729−
8731. (b) Cummins, C. C.; Baxter, S. M.; Wolczanski, P. T. J. Am.
Chem. Soc. 1988, 110, 8731−8733. (c) Hill, J. E.; Profilet, R. D.;
Fanwick, P. E.; Rothwell, I. P. Angew. Chem., Int. Ed. Engl. 1990, 29,
664−665. (d) Roesky, H. W.; Voelker, H.; Witt, M.; Noltemeyer, M.
Angew. Chem., Int. Ed. Engl. 1990, 29, 669−670. (e) Walsh, P. J.;
Hollander, F. J.; Bergman, R. G. Organometallics 1993, 12, 3705−3723.
(f) Dunn, S. C.; Batsanov, A. S.; Mountford, P. J. Chem. Soc., Chem.
Commun. 1994, 2007−2008. (g) Bennett, J. L.; Wolczanski, P. T. J.
Am. Chem. Soc. 1994, 116, 2179−2180. (h) Meyer, K. E.; Walsh, P. J.;
Bergman, R. G. J. Am. Chem. Soc. 1995, 117, 974−985. (i) Polse, J. L.;
Andersen, R. A.; Bergman, R. G. J. Am. Chem. Soc. 1998, 120, 13405−
13414. (j) Hoyt, H. M.; Michael, F. E.; Bergman, R. G. J. Am. Chem.
Soc. 2004, 126, 1018−1019. (k) Lian, B.; Spaniol, T. P.; Horrillo-
Martínez, P.; Hultzsch, K. C.; Okuda, J. Eur. J. Inorg. Chem. 2009,
2009, 429−434. (l) Tiong, P. J.; Nova, A.; Clot, E.; Mountford, P.
Chem. Commun. 2011, 47, 3147−3149. (m) Tiong, P. J.; Nova, A.;
Schwarz, A. D.; Selby, J. D.; Clot, E.; Mountford, P. Dalton Trans.
2012, 41, 2277−2288. (n) Schwarz, A. D.; Nielson, A. J.; Kaltsoyannis,
N.; Mountford, P. Chem. Sci. 2012, 3, 819−824.
́
(t) Camp, C.; Pecaut, J.; Mazzanti, M. J. Am. Chem. Soc. 2013, 135,
12101−12111. (u) King, D. M.; Tuna, F.; McInnes, E. J. L.; McMaster,
J.; Lewis, W.; Blake, A. J.; Liddle, S. T. Science 2012, 337, 717−720.
(v) King, D. M.; Tuna, F.; McInnes, E. J. L.; McMaster, J.; Lewis, W.;
Blake, A. J.; Liddle, S. T. Nat. Chem. 2013, 5, 482−488. (w) King, D.
M.; McMaster, J.; Tuna, F.; McInnes, E. J. L.; Lewis, W.; Blake, A. J.;
Liddle, S. T. J. Am. Chem. Soc. 2014, 136, 5619−5622.
(3) For selected papers on actinide metallocenes containing terminal
imido groups, see: (a) Cramer, R. E.; Panchanatheswaran, K.; Gilje, J.
W. J. Am. Chem. Soc. 1984, 106, 1853−1854. (b) Brennan, J. G.;
Andersen, R. A. J. Am. Chem. Soc. 1985, 107, 514−516. (c) Rosen, R.
K.; Andersen, R. A.; Edelstein, N. M. J. Am. Chem. Soc. 1990, 112,
4588−4590. (d) Arney, D. S. J.; Burns, C. J.; Smith, D. C. J. Am. Chem.
Soc. 1992, 114, 10068−10069. (e) Arney, D. S. J.; Burns, C. J. J. Am.
Chem. Soc. 1993, 115, 9840−9841. (f) Arney, D. S. J.; Burns, C. J. J.
Am. Chem. Soc. 1995, 117, 9448−9460. (g) Straub, T.; Frank, W.;
Reiss, G. J.; Eisen, M. S. J. Chem. Soc., Dalton Trans. 1996, 2541−2546.
(h) Warner, B. P.; Scott, B. L.; Burns, C. J. Angew. Chem., Int. Ed. 1998,
37, 959−960. (i) Peters, R. G.; Warner, B. P.; Scott, B. L.; Burns, C. J.
Organometallics 1999, 18, 2587−2589. (j) Straub, T.; Haskel, A.;
Neyroud, T. G.; Kapon, M.; Botoshansky, M.; Eisen, M. S.
Organometallics 2001, 20, 5017−5035. (k) Kiplinger, J. L.; Morris,
D. E.; Scott, B. L.; Burns, C. J. Chem. Commun. 2002, 30−31.
(l) Evans, W. J.; Kozimor, S. A.; Ziller, J. W. Chem. Commun. 2005,
4681−4683. (m) Graves, C. R.; Scott, B. L.; Morris, D. E.; Kiplinger, J.
L. J. Am. Chem. Soc. 2007, 129, 11914−11915. (n) Graves, C. R.; Yang,
P.; Kozimor, S. A.; Vaughn, A. E.; Clark, D. L.; Conradson, S. D.;
Schelter, E. J.; Scott, B. L.; Thompson, J. D.; Hay, P. J.; Morris, D. E.;
Kiplinger, J. L. J. Am. Chem. Soc. 2008, 130, 5272−5285. (o) Graves,
C. R.; Scott, B. L.; Morris, D. E.; Kiplinger, J. L. Organometallics 2008,
27, 3335−3337. (p) Graves, C. R.; Vaughn, A. E.; Schelter, E. J.; Scott,
B. L.; Thompson, J. D.; Morris, D. E.; Kiplinger, J. L. Inorg. Chem.
2008, 47, 11879−11891. (q) Spencer, L. P.; Gdula, R. L.; Hayton, T.
W.; Scott, B. L.; Boncella, J. M. Chem. Commun. 2008, 4986−4988.
(r) Evans, W. J.; Traina, C. A.; Ziller, J. W. J. Am. Chem. Soc. 2009, 131,
17473−17481. (s) Graves, C. R.; Scott, B. L.; Morris, D. E.; Kiplinger,
J. L. Chem. Commun. 2009, 776−778. (t) Evans, W. J.; Montalvo, E.;
Ziller, J. W.; DiPasquale, A. G.; Rheingold, A. L. Inorg. Chem. 2010, 49,
222−228. (u) Thomson, R. K.; Cantat, T.; Scott, B. L.; Morris, D. E.;
Batista, E. R.; Kiplinger, J. L. Nat. Chem. 2010, 2, 723−729. (v) Zi, G.;
Jia, L.; Werkema, E. L.; Walter, M. D.; Gottfriedsen, J. P.; Andersen, R.
A. Organometallics 2005, 24, 4251−4262. (w) Zi, G.; Blosch, L. L.; Jia,
L.; Andersen, R. A. Organometallics 2005, 24, 4602−4612.
(4) (a) Haskel, A.; Straub, T.; Eisen, M. S. Organometallics 1996, 15,
3773−3775. (b) Korobkov, I.; Gambarotta, S.; Yap, G. P. A. Angew.
Chem., Int. Ed. 2003, 42, 814−818. (c) Schelter, E. J.; Morris, D. E.;
Scott, B. L.; Kiplinger, J. L. Chem. Commun. 2007, 1029−1031.
(5) Selected papers on scandium imido complexes: (a) Scott, J.;
Basuli, F.; Fout, A. R.; Huffman, J. C.; Mindiola, D. J. Angew. Chem.,
Int. Ed. 2008, 47, 8502−8505. (b) Lu, E.; Li, Y.; Chen, Y. Chem.
Commun. 2010, 46, 4469−4471. (c) Lu, E.; Chu, J.; Borzov, M.; Chen,
Y.; Li, G. Chem. Commun. 2011, 47, 743−745. (d) Chu, J.; Lu, E.; Liu,
Z.; Chen, Y.; Leng, X.; Song, H. Angew. Chem., Int. Ed. 2011, 50,
7677−7680. (e) Lu, E.; Zhou, Q.; Li, Y.; Chu, J.; Chen, Y.; Leng, X.;
Sun, J. Chem. Commun. 2012, 48, 3403−3405. (f) Jian, Z.; Rong, W.;
Mou, Z.; Pan, Y.; Xie, H.; Cui, D. Chem. Commun. 2012, 48, 7516−
7518. (g) Wicker, B. F.; Fan, H.; Hickey, A. K.; Crestani, M. G.; Scott,
J.; Pink, M.; Mindiola, D. J. J. Am. Chem. Soc. 2012, 134, 20081−
(7) For selected recent papers on the bonding of organoactinide
complexes, see: (a) Cantat, T.; Graves, C. R.; Jantunen, K. C.; Burns,
C. J.; Scott, B. L.; Schelter, E. J.; Morris, D. E.; Hay, P. J.; Kiplinger, J.
L. J. Am. Chem. Soc. 2008, 130, 17537−17551. (b) Barros, N.; Maynau,
D.; Maron, L.; Eisenstein, O.; Zi, G.; Andersen, R. A. Organometallics
2007, 26, 5059−5065. (c) Yahia, A.; Maron, L. Organometallics 2009,
28, 672−679. (d) Walensky, J. R.; Martin, R. L.; Ziller, J. W.; Evans, W.
J. Inorg. Chem. 2010, 49, 10007−10012. (e) Ren, W.; Deng, X.; Zi, G.;
Fang, D.-C. Dalton Trans. 2011, 40, 9662−9664. (f) Seaman, L. A.;
Pedrick, E. A.; Tsuchiya, T.; Wu, G.; Jakubikova, E.; Hayton, T. W.
Angew. Chem., Int. Ed. 2013, 52, 10589−10592. (g) Gardner, B. M.;
Cleaves, P. A.; Kefalidis, C. E.; Fang, J.; Maron, L.; Lewis, W.; Blake, A.
J.; Liddle, S. T. Chem. Sci. 2014, 5, 2489−2497.
(8) Ren, W.; Zi, G.; Fang, D.-C.; Walter, M. D. J. Am. Chem. Soc.
2011, 133, 13183−13196.
(9) Ren, W.; Zi, G.; Fang, D.-C.; Walter, M. D. Chem. - Eur. J. 2011,
17, 12669−12682.
(10) Ren, W.; Zi, G.; Walter, M. D. Organometallics 2012, 31, 672−
679.
(11) Ren, W.; Zhou, E.; Fang, B.; Zi, G.; Fang, D.-C.; Walter, M. D.
Chem. Sci. 2014, 5, 3165−3172.
(12) Ren, W.; Zhou, E.; Fang, B.; Hou, G.; Zi, G.; Fang, D.-C.;
Walter, M. D. Angew. Chem., Int. Ed. 2014, 53, 11310−11314.
(13) Ren, W.; Song, H.; Zi, G.; Walter, M. D. Dalton Trans. 2012, 41,
5965−5973.
(14) Pool, J. A.; Scott, B. L.; Kiplinger, J. L. J. Am. Chem. Soc. 2005,
127, 1338−1339.
(15) Ren, W.; Lukens, W. W.; Zi, G.; Maron, L.; Walter, M. D. Chem.
Sci. 2013, 4, 1168−1174.
(16) Edelman, M. A.; Hitchcock, P. B.; Hu, J.; Lappert, M. F. New J.
Chem. 1995, 19, 481−489.
(17) Fang, B.; Ren, W.; Hou, G.; Zi, G.; Fang, D.-C.; Maron, L.;
Walter, M. D. J. Am. Chem. Soc. 2014, 136, 17249−17261.
(18) Marsh, R. E.; Kapon, M.; Hu, S.; Herbstein, F. H. Acta
Crystallogr., Sect. B: Struct. Sci. 2002, 58, 62−77.
(19) Fang, B.; Hou, G.; Zi, G.; Fang, D.-C.; Walter, M. D. Dalton
Trans. 2015, 44, 7927−7934.
(20) Ren, W.; Zhao, N.; Chen, L.; Song, H.; Zi, G. Inorg. Chem.
Commun. 2011, 14, 1838−1841.
3646
DOI: 10.1021/acs.organomet.5b00454
Organometallics 2015, 34, 3637−3647

Organometallics
Article
(21) Blake, P. C.; Lappert, M. F.; Taylor, R. G.; Atwood, J. L.;
Hunter, W. E.; Zhang, H. J. Chem. Soc., Dalton Trans. 1995, 3335−
3341.
(22) Fang, B.; Zhang, L.; Hou, G.; Zi, G.; Fang, D.-C.; Walter, M. D.
Chem. Sci. 2015, DOI: 10.1039/c5sc01684c.
(23) Sheldrick, G. M. SADABS, Program for Empirical Absorption
Correction of Area Detector Data; University of Gottingen: Gottingen,
̈
̈
Germany, 1996.
(24) (a) Sheldrick, G. M. SHELXL-97, Program for the Refinement of
Crystal Structure from Diffraction Data; University of Gottingen:
̈
Gottingen, Germany, 1997. (b) Sheldrick, G. M. Acta Crystallogr., Sect.
A 2008, 64, 112−122.
̈
(25) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.;
Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Mennucci,
B.; Petersson, G. A.; Nakatsuji, H.; Caricato, M.; Li, X.; Hratchian, H.
P.; Izmaylov, A. F.; Bloino, J.; Zheng, G.; Sonnenberg, J. L.; Hada, M.;
Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima,
T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Montgomery, J. A., Jr.;
Peralta, J. E.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.; Kudin,
K. N.; Staroverov, V. N.; Kobayashi, R.; Normand, J.; Raghavachari, K.;
Rendell, A.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Rega,
N.; Millam, J. M.; Klene, M.; Knox, J. E.; Cross, J. B.; Bakken, V.;
Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.;
Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Martin, R. L.;
Morokuma, K.; Zakrzewski, V. G.; Voth, G. A.; Salvador, P.;
Dannenberg, J. J.; Dapprich, S.; Daniels, A. D.; Farkas, O.;
Foresman, J. B.; Ortiz, J. V.; Cioslowski, J.; Fox, D. J. Gaussian 09,
revision A.02, Gaussian, Inc.: Wallingford, CT, 2009.
(26) Grimme, S.; Antony, J.; Ehrlich, S.; Krieg, H. J. Chem. Phys.
2010, 132, 154104.
(27) Kuchle, W.; Dolg, M.; Stoll, H.; Preuss, H. Mol. Phys. 1991, 74,
̈
1245−1263.
3647
DOI: 10.1021/acs.organomet.5b00454
Organometallics 2015, 34, 3637−3647