A base-free terminal thorium phosphinidene metallocene and its reactivity toward selected organic molecules

Article abstract of DOI:10.1039/C9DT00012G

The stable base-free terminal phosphinidene thorium metallocene, [η⁵-1,2,4-(Me₃C)₃C₅H₂]₂Th═P-2,4,6-^tBu₃C₆H₂ (2), can be isolated from the reactio

Full text of DOI:10.1039/C9DT00012G

Dalton
Transactions
View Article Online
View Journal
PAPER
A base-free terminal thorium phosphinidene
metallocene and its reactivity toward selected
Cite this: DOI: 10.1039/c9dt00012g
organic molecules†
b
Congcong Zhang,a Guohua Hou, a Guofu Zi *a and Marc D. Walter
*
The stable base-free terminal phosphinidene thorium metallocene, [η5-1,2,4-(Me3C)3C5H2]2
ThvP-2,4,6-tBu3C6H2 (2), can be isolated from the reaction of the thorium dichloride complex [η5-1,2,4-
(Me3C)3C5H2]2ThCl2 (1) with 2 equiv. of 2,4,6-(Me3C)3C6H2PHK in THF. The reactivity of 2 in the activation
of various small organic molecules such as diselenides, phosphines, imines, ketones, phosphine oxides,
thiazole, imidazole derivatives and amines was explored. For example, when complex 2 is treated with
Ph2Se2, the phosphinidene is replaced, yielding diselenido compound [η5-1,2,4-(Me3C)3C5H2]2Th(SePh)2
(3). Moreover, E–H (E = P, N, C) bond activation occurs on exposure of 2 to 2,4,6-iPr3C6H2PH2, PhPH2,
(p-tolyl)2CvNH, 1-indanone, cyclohexanone, Me3PO, thiazole, 1-methylimidazole and p-toluidine,
resulting in the phosphido complex [η5-1,2,4-(Me3C)3C5H2][η5,κ-C-1,2-(Me3C)2-4-(CH2CMe2)C5H2]Th
(PH-2,4,6-iPr3C6H2) (4), the metallaheterocycle [η5-1,2,4-(Me3C)3C5H2]2Th(η2-P2Ph2) (5), the iminato
phosphido complex [η5-1,2,4-(Me3C)3C5H2]2Th(PH-2,4,6-tBu3C6H2)[NvC(p-tolyl)2] (6), the phosphido
enolyl compound [η5-1,2,4-(Me3C)3C5H2]2Th(PH-2,4,6-tBu3C6H2)(κ-O-1-OC9H7) (7), the enolyl complex
[η5-1,2,4-(Me3C)3C5H2][η5,κ-C-1,2-(Me3C)2-4-(CH2CMe2)C5H2]Th(κ-O-1-OC6H9) (8), the alkyl complex
[η5-1,2,4-(Me3C)3C5H2][η5,κ-C-1,2-(Me3C)2-4-(CH2CMe2)C5H2]Th(κ-O,C-OPMe2CH2) (9), the phosphido
thiazolyl complex [η5-1,2,4-(Me3C)3C5H2]2Th(PH-2,4,6-tBu3C6H2)(C3H2NS) (10), the bis-imidazolyl
complex [η5-1,2,4-(Me3C)3C5H2]2Th[2-(1-MeC3H2N2)]2 (11), and the imido complex [η5-1,2,4-
(Me3C)3C5H2]2ThvN(p-tolyl) (12), respectively. Several spectroscopic techniques were employed for the
characterisation of the new complexes 3–11, and in addition the solid-state molecular structures of com-
pounds 3–6, 8–9 and 11 were further confirmed by X-ray diffraction analyses.
Received 2nd January 2019,
Accepted 22nd January 2019
DOI: 10.1039/c9dt00012g
rsc.li/dalton
neglected and therefore their inherent reactivity is still await-
ing further exploration.4,5 An interesting starting point in this
Introduction
Over the past decades phosphinidene complexes have been an endeavour represents thorium, since the Th atom possesses a
active area of chemical research mainly driven by their high [Rn] 6d27s2 electronic ground state, and therefore similar reac-
reactivity and their ability to access new phosphorus contain- tivity to those of early transition metals, for which several com-
ing molecules, organometallic derivatives and new materials. plexes with MvPR bonds are already known,2 might emerge.
Furthermore, they can be employed to efficiently form phos- Nevertheless, in recent studies on small molecule activation
phorus-element bonds in stoichiometric and catalytic using actinide compounds6 the subtle influence of 6d and 5f
transformations.1–3 Most of these research activities involved orbitals on the reactivity of theses actinide species was estab-
d-transition metals,1–4 whereas related terminal phosphin- lished.7 Detailed investigations revealed that the 5f orbital con-
idene actinide and lanthanide complexes have been largely tribution indeed modulates the bonding and reactivity of organo-
thorium compounds, thus leading to distinctively different
reactivity patterns compared to that of Group 4 complexes.7
aDepartment of Chemistry, Beijing Normal University, Beijing 100875, China.
E-mail: gzi@bnu.edu.cn
bInstitut für Anorganische und Analytische Chemie, Technische Universität
Braunschweig, Hagenring 30, 38106 Braunschweig, Germany.
E-mail: mwalter@tu-bs.de
These aspects motivated us to prepare actinide compounds
with terminal metal–ligand multiple-bonds and to probe their
intrinsic properties.8 In the course of our investigations, we
have recently reported on the base-free terminal thorium
imido metallocene [η5-1,2,4-(Me3C)3C5H2]2ThvN(p-tolyl)8c–g
and the related base-free terminal thorium phosphinidene
metallocene [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2).9
†Electronic supplementary information (ESI) available: Crystal parameters.
CCDC 1883596–1883602. For ESI and crystallographic data in CIF or other elec-
tronic format see DOI: 10.1039/c9dt00012g
This journal is © The Royal Society of Chemistry 2019
Dalton Trans.

View Article Online
Paper
Dalton Transactions
We noted some differences in their reactivity, e.g. whereas the (Me3C)3C5H2]2Th(SePh)2 (3) in 93% isolated yield and the
ThvNR moiety in the thorium imido metallocene [η5-1,2,4- phosphaindane 3,3-Me2-5,7-tBu2C8H5P (Scheme 2). The mole-
(Me3C)3C5H2]2ThvN(p-tolyl) forms stable [2 + 2] or [2 + 3] cular structure of 3 is depicted in Fig. 1, and selected bond dis-
cycloaddition products with internal alkynes and hetero-unsa- tances and angles can be found in Table 1. The Th–Se dis-
turated molecules,8c–g the ThvPR functionality in the thorium tances are 2.880(1) and 2.871(1) Å, which are close to
phosphinidene 2 remains inert to alkynes, but it reacts with a those observed for [η5-1,3-(Me3C)2C5H3]2Th(SePh)2 (2.854(2)
variety of hetero-unsaturated molecules such as CS2, isothio- and 2.900(1) Å).10
cyanate, nitriles, isonitriles, and organic azides, yielding carbo-
Complex 2 may also act as strong base inducing inter- or
dithioates, imido complexes, metallaaziridines, and azido intra-molecular E–H bond activations similar to the thorium
compounds.9 These distinctively different reactivity patterns imido metallocenes.8e–g,i For example, reaction of 2 with
encouraged us to also extend our substrate scope, and these
1
equiv. of phosphine 2,4,6-iPr3C6H2PH2 gives the
results are reported herein. For completeness we also include a phosphido complex [η5-1,2,4-(Me3C)3C5H2][η5,κ-C-1,2-(Me3C)2-
comparison with the reactivity of the related thorium imido 4-(CH2CMe2)C5H2]Th(PH-2,4,6-iPr3C6H2) (4) in 72% yield
metallocenes.8
(Scheme 3). A plausible mechanism may involve the reaction
of 2 with 2,4,6-iPr3C6H2PH2 to yield after deprotonation a
phosphinidene complex, that, however, converts to 4 via C–H
bond activation of a methyl group of the 1,2,4-(Me3C)3C5H2
ligand (Scheme 3) analogous to the formation of thorium
tuck-in complexes.11 The 31P{1H} NMR spectrum of 4 features
a singlet at δ = 3.3 ppm, corresponding to a phosphido
ligand.12 Complex 4 was structurally characterized (Fig. 2),
whereas Table 1 provides selected bond distances and angles.
Results and discussion
Treatment of [η5-1,2,4-(Me3C)3C5H2]2ThCl2 (1) with 2 equiv.
of 2,4,6-(Me3C)3C6H2PHK in THF affords the base-free
terminal phosphinidene thorium metallocene, [η5-1,2,4-
(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2) and 2,4,6-(Me3C)3
C6H2PH2 (Scheme 1). We propose that the product formation
can be rationalized by an initial reaction of 1 with 1 equiv. of
2,4,6-(Me3C)3C6H2PHK to give a phosphido chloride complex,
which further converts with a second molecule of 2,4,6-
(Me3C)3C6H2PHK to form 2, 2,4,6-(Me3C)3C6H2PH2 and KCl
(Scheme 1). Overall, this new approach obviates the previous
need for the thorium dimethyl metallocene [η5-1,2,4-
(Me3C)3C5H2]2ThMe2 and thorium methyl iodide metallocene
[η5-1,2,4-(Me3C)3C5H2]2Th(I)Me as starting materials.9 The
identity of 2 was confirmed by NMR spectroscopy,9 whereas
variable-temperature (20–100 °C) 1H NMR investigations estab-
lished that
2 remains intact when heated to 100 °C.
Nevertheless, contrary to the reactivity of the thorium imido
[η5-1,2,4-(Me3C)3C5H2]2ThvN(p-tolyl) toward Ph2Se2,8g we now
observe phosphinidene replacement in the reaction of 2
with Ph2Se2 to give the diselenido complex [η5-1,2,4-
Scheme 2 Synthesis of complex 3.
Fig. 1 Molecular structure of 3 (thermal ellipsoids drawn at the 35%
Scheme 1 Synthesis of complex 2.
probability level).
Dalton Trans.
This journal is © The Royal Society of Chemistry 2019

View Article Online
Dalton Transactions
Paper
Table 1 Selected distances (Å) and angles (°) for compounds 3–6, 8–9 and 11 a
Compound
C(Cp)–Thb
C(Cp)–Thc
Cp(cent)–Thb
Th–X
Cp(cent)–Th–Cp(cent)
X–Th–X/Y
3
4
5
6
8
9
2.861(3)
2.818(12)
2.842(5)
2.890(5)
2.832(4)
2.876(9)
2.785(3) to 2.956(3)
2.712(12) to 2.969(11)
2.765(4) to 2.937(5)
2.805(5) to 2.972(5)
2.675(4) to 2.930(4)
2.707(9) to 3.047(9)
2.593(3)
2.544(11)
2.572(5)
2.626(5)
2.561(4)
2.610(9)
Se1: 2.880(1), Se2: 2.871(1)
C16: 2.575(11), P1: 2.937(3)
P1: 2.877(1), P1A: 2.877(1)
N1: 2.239(4), P1: 3.005(1)
C15: 2.515(5), O1: 2.153(3)
C34: 2.514(10), C37: 2.692(10),
O1: 2.442(6)
138.5(1)
147.3(3)
143.5(1)
136.0(1)
143.3(1)
139.1(3)
90.5(1)
100.7(3)
44.0(1)
96.3(1)
95.6(1)
60.2(3)d
11
2.890(3)
2.850(3) to 2.947(3)
2.626(3)
C18: 2.479(4), N1: 2.507(3)
141.0(1)
31.3(1)e
a Cp = cyclopentadienyl ring. b Average value. c Range. d The angle of C37–Th–O1. e The angle of C18–Th–N1.
Scheme 3 Synthesis of complex 4.
Scheme 4 Synthesis of complex 5.
is isolated in 94% yield from the reaction of 2 with the less
sterically encumbered phosphine PhPH2, which contains a
three-membered metallaheterocycle [η5-1,2,4-(Me3C)3C5H2]2Th
(η2-P2Ph2) (5). As side-products the phosphine 2,4,6-
(Me3C)3C6H2PH2 and H2 were formed (Scheme 4). We also
probed the influence of different quantities of PhPH2 added to
the reaction mixture, but no influence on the product for-
mation was noted. In analogy to the formation of the zirco-
nium complex (η5-C5Me5)2Zr(η2-P2Mes2),2a,c reaction of 2 with
Fig. 2 Molecular structure of 4 (thermal ellipsoids drawn at the 35% 1 equiv. of PhPH2 gives a phosphinidene intermediate after
probability level).
deprotonation, which forms with a second molecule of PhPH2
a phosphido hydride complex, that further releases H2 to yield
5 (Scheme 4). Alternatively, the reaction of 2 with 2 equiv. of
The Th–C(16) distance is 2.575(11) Å, whereas the Th–P dis- PhPH2 affords a bis(phosphido) intermediate, that eliminates
tance is significantly elongated with 2.937(3) Å compared to H2 to yield 5 (Scheme 4). The molecular structure of 5 is
that found in 2 (2.536(2) Å).9 However, a very different product presented in Fig. 3, and selected bond distances and angles
This journal is © The Royal Society of Chemistry 2019
Dalton Trans.

View Article Online
Paper
Dalton Transactions
Fig. 3 Molecular structure of 5 (thermal ellipsoids drawn at the 35%
probability level).
are listed in Table 1. The Th–P and P–P distances are 2.877(1)
Å and 2.162(3) Å, respectively, whereas the P–Th–P angle is
44.0(1)°.
Fig. 4 Molecular structure of 6 (thermal ellipsoids drawn at the 35%
probability level).
Deprotonation also occurs between
2 and the imine
(p-tolyl)2CvNH to afford an iminato phosphido complex [η5-
1,2,4-(Me3C)3C5H2]2Th(PH-2,4,6-tBu3C6H2)[NvC(p-tolyl)2] (6)
in 78% yield (Scheme 5). The 31P{1H} NMR spectrum of 6 fea-
tures a singlet at δ = −18.9 ppm, which is in line with a phos-
phido ligand.12 The ORTEP of 6 is shown in Fig. 4, while rele-
vant bond distances and angles are given in Table 1. The Th–P
and Th–N distances are 3.005(1) Å and 2.239(4) Å, respectively,
while the P–Th–N angle approaches 90° with 96.3(1)°. An
additional example of deprotonation represents the reaction of
2 and 1-indanone to yield the phosphido enolyl compound [η5-
1,2,4-(Me3C)3C5H2]2Th(PH-2,4,6-tBu3C6H2)(κ-O-1-OC9H7) (7) in
82% yield (Scheme 5). The 31P{1H} NMR spectrum of 7 features
a resonance at δ = 5.0 ppm, which agrees with a phosphido
ligand and is close to that found in 4. In contrast, treatment of
2 with 1 equiv. of cyclohexanone affords only an enolyl
tuck-in complex [η5-1,2,4-(Me3C)3C5H2][η5,κ-C-1,2-(Me3C)2-4-
(CH2CMe2)C5H2]Th(κ-O-1-OC6H9) (8) concomitant phosphine
2,4,6-(Me3C)3C6H2PH2 loss (Scheme 6), presumably a conse-
Scheme 6 Synthesis of complex 8.
quence of the steric and electronic properties of the ketone,
and complex 8 was isolated in 73% yield. Two alternative
mechanisms may explain the formation of 8: Upon cyclo-
hexanone coordination to the thorium atom a C–H bond acti-
vation of a methyl group of the 1,2,4-(Me3C)3C5H2 ligand
occurs to yield a phosphido intermediate, followed by deproto-
nation of the coordinated cyclohexanone, that forms 8 and
releases the phosphine 2,4,6-(Me3C)3C6H2PH2 (Scheme 6).
Scheme 5 Synthesis of complexes 6, 7 and 10.
Dalton Trans.
This journal is © The Royal Society of Chemistry 2019

View Article Online
Dalton Transactions
Paper
Alternatively, complex 8 can also be the result of the deproto-
nation of the coordinated cyclohexanone, followed by a C–H
bond activation of a methyl group of the 1,2,4-(Me3C)3C5H2
ligand along with phosphine 2,4,6-(Me3C)3C6H2PH2 loss
(Scheme 6). An ORTEP of 8 is shown in Fig. 5, whereas selected
bond distances and angles are provided in Table 1. The Th–C
and Th–O bond distances differ substantially with 2.515(5) Å
and 2.153(3) Å, respectively. Related reactivity is also observed
between 2 and trimethylphosphine oxide, yielding an alkyl
tuck-in complex [η5-1,2,4-(Me3C)3C5H2][η5,κ-C-1,2-(Me3C)2-4-
(CH2CMe2)C5H2]Th(κ-O,C-OPMe2CH2) (9) in 70% yield, while
the phosphine 2,4,6-(Me3C)3C6H2PH2 is released (Scheme 7).
In analogy to the formation of 8, Me3PO coordination to the
thorium atom results in a C–H bond activation of a methyl
group of the 1,2,4-(Me3C)3C5H2 ligand to yield a phosphido
intermediate, followed by deprotonation of the coordinated
Me3PO, that forms 9 and releases the phosphine 2,4,6-
(Me3C)3C6H2PH2 (Scheme 7). Alternatively, complex 9 may also
be formed by the deprotonation of the coordinated Me3PO,
followed by a C–H bond activation of a methyl group of
the 1,2,4-(Me3C)3C5H2 ligand concomitant phosphine 2,4,6-
(Me3C)3C6H2PH2 loss (Scheme 7). The molecular structure of 9
is presented in Fig. 6, and for the interested reader some rele-
vant bond distances and angles are collected in Table 1. The
Th–C(34) and Th–C(37) distances differ significantly with
2.514(10) Å and 2.692(10) Å, respectively, while the Th–O dis-
tance of 2.442(6) Å is substantially elongated compared to that
established for 8 (2.153(3) Å).
Scheme 7 Synthesis of complex 9.
When the potassium chloride bridged thorium phosphini-
diide {[η5-1,3-(Me3C)2C5H3]2Th(vP-2,4,6-tBu3C6H2)(ClK)}2 was
reacted with thiazole, thiazole ring opening occurred.12
However, when 2 is exposed to thiazole, the reactivity is closely
related to that of the analogous thorium imido complexes,8i
resulting in the phosphido thiazolyl complex [η5-1,2,4-
(Me3C)3C5H2]2Th(PH-2,4,6-tBu3C6H2)(C3H2NS) (10) in 85%
yield (Scheme 5). The 31P{1H} NMR spectrum of 10 shows a
resonance at δ = −10.5 ppm, which is in the same range as
that found in 6. Nevertheless, treatment of 2 with 1-methyl-
imidazole affords the bis-imidazolyl complex [η5-1,2,4-
Fig. 6 Molecular structure of 9 (thermal ellipsoids drawn at the 35%
probability level).
(Me3C)3C5H2]2Th[2-(1-MeC3H2N2)]2 (11) and the phosphine
2,4,6-(Me3C)3C6H2PH2 (Scheme 8), irrespectively of the amount
of 1-methylimidazole employed. Complex 11 was isolated in
78% yield and it features similar Th–C(18) and Th–N(1) dis-
tances with 2.479(4) Å and 2.507(3) Å, respectively (Fig. 7).
Interestingly, deprotonation also occurs between 2 and p-tolui-
dine to afford the known imido complex [η5-1,2,4-
(Me3C)3C5H2]2ThvN(p-tolyl) (12) (83% isolated yield)8c,d and
phosphine 2,4,6-(Me3C)3C6H2PH2 (Scheme 8).
Fig. 5 Molecular structure of 8 (thermal ellipsoids drawn at the 35%
probability level).
This journal is © The Royal Society of Chemistry 2019
Dalton Trans.

View Article Online
Paper
Dalton Transactions
Experimental
General methods
All reactions and product manipulations were conducted
under a dry dinitrogen atmosphere with rigid exclusion of air
and moisture using standard Schlenk or cannula techniques,
or in a glove box. Organic solvents were freshly distilled from
sodium benzophenone ketyl immediately prior to use.
[η5-1,2,4-(Me3C)3C5H2]2ThCl2 (1),8c,d 2,4,6-tBu3C6H2PH2 and
13
2,4,6-tBu3C6H2PHK14 were prepared according to literature pro-
cedures, whereas the remaining chemicals were purchased
from Aldrich Chemical Co. and Beijing Chemical Co. and used
as received unless stated otherwise. Infrared spectra were
recorded in KBr pellets on an Avatar 360 Fourier transform
1
spectrometer. H, 13C{1H} and 31P{1H} NMR spectra were col-
lected on a Bruker AV 400 spectrometer at 400, 100 and
162 MHz, respectively. Chemical shifts are reported in δ units
with reference to the residual protons of the deuterated sol-
vents, which served as internal standards, for proton and
carbon chemical shifts, and to external 85% H3PO4 (0.00 ppm)
for phosphorus chemical shifts. Melting points were measured
on an X-6 melting point apparatus and were uncorrected.
Elemental analyses were performed on a Vario EL elemental
analyzer.
Scheme 8 Synthesis of complexes 11 and 12.
Syntheses
Preparation of [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2
(2). Method A. A THF (20 mL) solution of 2,4,6-tBu3C6H2PHK
(632 mg, 2.0 mmol) was added to a THF (10 mL) solution of
[η5-1,2,4-(Me3C)3C5H2]2ThCl2 (1; 770 mg, 1.0 mmol) with stir-
ring at room temperature. After the solution was stirred at
room temperature overnight, the solvent was removed. The
residue was extracted with benzene (10 mL × 3) and filtered.
The volume of the filtrate was reduced to 10 mL, orange micro-
crystals of 2 were isolated when this solution was stored at
Fig. 7 Molecular structure of 11 (thermal ellipsoids drawn at the 35%
probability level).
1
room temperature for two days. Yield: 828 mg (85%). H NMR
(C6D6): δ 7.64 (s, 2H, phenyl), 7.33 (s, 2H, ring CH), 7.15 (s, 6H,
C6H6), 6.03 (d, J = 2.8 Hz, 2H, ring CH), 2.20 (s, 18H, C(CH3)3),
1.64 (s, 18H, C(CH3)3), 1.58 (s, 18H, C(CH3)3), 1.46 (s, 18H,
Conclusions
While the coordinated nitrene moiety in the thorium imido C(CH3)3), 1.32 (s, 9H, C(CH3)3) ppm. 31P{1H} NMR (C6D6):
metallocene is inert to ligand exchange,8 complex 2 may serve δ 145.7 ppm. These spectroscopic data agreed with those
as [η5-1,2,4-(Me3C)3C5H2]2Th(II) synthon in the reaction with reported in the literature.9
Ph2Se2, which results in the displacement of the coordinated
Method B. NMR scale. A THF (0.5 mL) solution of
phosphinidene fragment. The reactivity difference between the 2,4,6-tBu3C6H2PHK (6.3 mg; 0.02 mmol) was added to a
imido and phosphinidene thorium complexes can be rational- J. Young NMR tube charged with [η5-1,2,4-(Me3C)3C5H2]2ThCl2
ised by a more facile oxidation of the phosphinidene ligand (1; 7.8 mg, 0.01 mmol) and THF (0.5 mL). The solvent was
compared to the imido ligand. Nevertheless, complex 2 also slowly removed after this sample was stored at room tempera-
exhibits a diverse reactivity toward several small organic mole- ture overnight. The residue was dissolved in C6D6 (0.5 mL),
cules such as phosphines, imines, ketones, phosphine oxides, resonances of 2 along with those of 2,4,6-tBu3C6H2PH2 (1H
thiazole, imidazole derivatives and amines, resulting in phos- NMR (C6D6): δ 7.54 (d, J = 2.2 Hz, 2H, phenyl), 4.25 (d, JP–H
=
phido, metallacycles, iminato, enolyl, alkyl, thiazolyl, imidazo- 207.3 Hz, 2H, PH2), 1.56 (s, 18H, C(CH3)3), 1.29 (s, 9H,
lyl and imido compounds via inter- or intra-molecular E–H C(CH3)3) ppm)13 were observed by 1H NMR spectroscopy
(E = P, N, C) bond activations, respectively. Further investigations (100% conversion).
regarding the intrinsic reactivity of actinide phosphinidenes and
Preparation of [η5-1,2,4-(Me3C)3C5H2]2Th(SePh)2 (3). Method
of the thorium metallaheterocycle 5 are currently in progress A. A toluene (5 mL) solution of Ph2Se2 (78 mg, 0.25 mmol) was
and these results will be subject of future contributions.
added to
a
toluene (10 mL) solution of [η5-1,2,4-
Dalton Trans.
This journal is © The Royal Society of Chemistry 2019

View Article Online
Dalton Transactions
Paper
(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2; 244 mg, 0.25 mmol) δ 3.3 ppm. IR (KBr, cm−1): ν 2958 (s), 2904 (s), 2868 (s), 1600
with stirring at room temperature. After the solution was (m), 1462 (s), 1386 (s), 1359 (s), 1238 (s), 1022 (m), 819 (s).
stirred at room temperature overnight, the solvent was
removed. The residue was extracted with benzene (10 mL × 3) 2,4,6-iPr3C6H2PH2 (4.7 mg, 0.02 mmol) was slowly added to
and filtered. The volume of the filtrate was reduced to 5 mL,
Method B. NMR scale. A C6D6 (0.3 mL) solution of
a
J. Young NMR tube charged with [η5-1,2,4-
colourless crystals of 3 were isolated when this solution was (Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2; 20 mg, 0.02 mmol)
stored at room temperature for 1 week. Yield: 235 mg (93%) and C6D6 (0.2 mL). Resonances of 4 along with those of
(Found: C, 54.69; H, 6.81. C46H68Se2Th requires C, 54.65; H, 2,4,6-tBu3C6H2PH2 were observed by 1H NMR spectroscopy
6.78%). M.p.: 144–146 °C. 1H NMR (C6D6): δ 7.99 (d, J = 7.2 Hz, (100% conversion) after the sample was kept at 110 °C
4H, phenyl), 7.08 (t, J = 7.6 Hz, 4H, phenyl), 6.94 (t, J = 7.3 Hz, overnight.
2H, phenyl), 6.50 (s, 4H, ring CH), 1.52 (s, 36H, C(CH3)3), 1.40
Preparation of [η5-1,2,4-(Me3C)3C5H2]2Th(η2-P2Ph2) (5).
(s, 18H, C(CH3)3) ppm. 13C{1H} NMR (C6D6): δ 149.4 (phenyl Method A. A toluene (5 mL) solution of PhPH2 (55 mg,
C), 149.0 (phenyl C), 137.5 (phenyl C), 136.6 (phenyl C), 128.8 0.50 mmol) was added to a toluene (10 mL) solution of
(ring C), 125.5 (ring C), 118.4 (ring C), 35.7 (C(CH3)3), 35.1 [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2; 244 mg,
(C(CH3)3), 34.7 (C(CH3)3), 32.8 (C(CH3)3) ppm. IR (KBr, cm−1): 0.25 mmol) without stirring at room temperature. After this
ν 2956 (s), 2868 (s), 1575 (s), 1472 (s), 1360 (s), 1238 (s), 1164 mixture was stored at room temperature for 2 days without stir-
(s), 1021 (s), 733 (s).
ring, orange crystals were isolated from the solution, which
Method B. NMR scale. A C6D6 (0.3 mL) solution of Ph2Se2 were identified as 5 by X-ray diffraction analysis. Yield: 215 mg
(6.2 mg, 0.02 mmol) was slowly added to a J. Young NMR tube (94%) (Found: C, 60.35; H, 7.47. C46H68P2Th requires C, 60.38;
charged with [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2; H, 7.49%). M.p.: >300 °C. IR (KBr, cm−1): ν 2963 (s), 1576 (s),
20 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 3 along 1471 (s), 1398 (s), 1261 (s), 1022 (s), 827 (s). This compound
with those of 3,3-Me2-5,7-tBu2C8H5P (1H NMR (C6D6): δ 7.46 was insoluble in common (deuterated) solvents such as pyri-
(dd, J = 3.8, 1.5 Hz, 2H, phenyl), 4.39 (ddd, J = 181.6, 11.9, dine, THF, toluene, and CD2Cl2, which prevented its character-
7.9 Hz, 1H, PH), 1.59 (d, J = 3.6 Hz, 1H CH2), 1.56 (s, 9H, ization by NMR spectroscopy.
(CH3)3C), 1.34 (s, 3H, (CH3), 1.31 (s, 9H, (CH3)3C), 1.29 (d, J =
Method B. NMR scale. A C6D6 (0.3 mL) solution of PhPH2
3.6 Hz, 1H CH2), 1.11 (s, 3H, (CH3) ppm. 31P{1H} NMR (C6D6): (4.4 mg, 0.04 mmol) was slowly added to a J. Young NMR tube
δ −79.5 ppm)9 were observed by NMR spectroscopy (100% con- charged with [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2;
version) after the sample was stored at room temperature 20 mg, 0.02 mmol) and C6D6 (0.2 mL). Orange crystals precipi-
overnight.
tated, and resonances of 2,4,6-tBu3C6H2PH2 and H2 (1H NMR
Preparation of [η5-1,2,4-(Me3C)3C5H2][η5,κ-C-1,2-(Me3C)2-4- (C6D6): δ 4.47 ppm) were observed by 1H NMR spectroscopy
(CH2CMe2)C5H2]Th(PH-2,4,6-iPr3C6H2) (4). Method A. This (100% conversion) after the sample was stored at room temp-
compound was obtained as orange crystals from the reaction erature for 2 days.
of [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2; 244 mg,
Reaction of [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2)
0.25 mmol) and 2,4,6-iPr3C6H2PH2 (59 mg, 0.25 mmol) in with PhPH2. NMR scale. A C6D6 (0.2 mL) solution of PhPH2
toluene (15 mL) at 110 °C and recrystallization from a benzene (2.2 mg, 0.02 mmol) was slowly added to a J. Young NMR tube
solution by a similar procedure as that in the synthesis of 3. charged with [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2;
Yield: 168 mg (72%) (Found: C, 63.08; H, 8.77. C49H81PTh 20 mg, 0.02 mmol) and C6D6 (0.3 mL). Orange crystals precipi-
1
requires C, 63.07; H, 8.75%). M.p.: 167–169 °C (dec.). H NMR tated, resonances of unreacted
2 along with those of
(C6D6): δ 7.17 (d, J = 2.9 Hz, 2H, phenyl), 6.63 (t, J = 2.4 Hz, 1H, 2,4,6-tBu3C6H2PH2 and H2 were observed by 1H NMR spec-
ring CH), 6.49 (t, J = 3.0 Hz, 1H, ring CH), 6.03 (t, J = 3.3 Hz, troscopy (50% conversion based on 2) after the sample was
2H, ring CH), 4.59 (d, JP–H = 230.4 Hz, 1H, PH), 3.89 (m, 2H, stored at room temperature for 2 days.
CH(CH3)2), 2.89 (m, 1H, CH(CH3)2), 1.68 (s, 3H, CH2C(CH3)2),
Preparation
of
[η5-1,2,4-(Me3C)3C5H2]2Th(PH-2,4,6-tBu3
1.59 (s, 3H, CH2C(CH3)2), 1.49 (d, J = 6.6 Hz, 12H, CH(CH3)2), C6H2)[NvC(p-tolyl)2]·0.5C6H14 (6·0.5C6H14). Method A. This
1.47 (s, 9H, C(CH3)3), 1.45 (s, 9H, C(CH3)3), 1.40 (s, 9H, compound was obtained as orange crystals from the reaction
C(CH3)3), 1.36 (s, 9H, C(CH3)3), 1.35 (s, 9H, C(CH3)3), 1.31 (d, of [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2; 244 mg,
J = 6.6 Hz, 6H, CH(CH3)2), 0.56 (d, J = 13.8 Hz, 1H, ThCH2), 0.25 mmol) and (p-tolyl)2CvNH (52 mg, 0.25 mmol) in
−0.80 (d, J = 13.2 Hz, 1H, ThCH2) ppm. 13C{1H} NMR (C6D6): toluene (15 mL) at room temperature and recrystallization
δ 150.8 (aryl C), 150.8 (aryl C), 146.7 (aryl C), 145.4 (ring C), from an n-hexane solution by a similar procedure as that in
145.3 (ring C), 144.2 (ring C), 141.9 (ring C), 139.4 (ring C), the synthesis of 3. Yield: 239 mg (78%) (Found: C, 68.48; H,
138.4 (d, JP–C = 13.8 Hz, phenyl C), 120.6 (ring C), 120.5 (ring 8.97; N, 1.12. C70H109NPTh requires C, 68.49; H, 8.95; N,
1
C), 116.5 (ring C), 114.8 (ring C), 113.4 (ring C), 69.7 (ThCH2), 1.14%). M.p.: 145–147 °C (dec.). H NMR (C6D6): δ 7.66 (d, J =
35.0 (C(CH3)3), 34.9 (C(CH3)3), 34.7 (C(CH3)3), 34.6 (C(CH3)3), 8.0 Hz, 4H, phenyl), 7.40 (d, J = 2.0 Hz, 2H, phenyl), 7.11 (d,
34.6 (C(CH3)3), 34.2 (C(CH3)3), 34.1 (C(CH3)3), 34.0 (C(CH3)3), J = 7.8 Hz, 4H, phenyl), 6.69 (s, 2H, ring CH), 6.60 (s, 2H, ring
33.8 (d, JP–C = 11.7 Hz, C(CH3)3), 32.7 (C(CH3)3, 32.6 (CH CH), 4.10 (d, JP–H = 209.0 Hz, 1H, ThPH), 2.15 (s, 6H, CH3),
(CH3)2), 26.6 (C(CH3)2), 24.7 (C(CH3)2), 24.6 (C(CH3)2), 24.2 1.81 (s, 18H, C(CH3)3), 1.51 (s, 18H, C(CH3)3), 1.44 (s, 9H,
(CH(CH3)2), 24.1 (CH(CH3)2) ppm. 31P{1H} NMR (C6D6): C(CH3)3), 1.42 (s, 18H, C(CH3)3), 1.37 (s, 18H, C(CH3)3), 1.26
This journal is © The Royal Society of Chemistry 2019
Dalton Trans.

View Article Online
Paper
Dalton Transactions
(m, 4H, CH2CH2), 0.89 (t, J = 6.9 Hz, 3H, CH2CH3) ppm. 13C [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2; 244 mg,
{1H} NMR (C6D6): δ 181.1 (ThNvC), 151.5 (phenyl C), 146.9 0.25 mmol) and cyclohexanone (25 mg, 0.25 mmol) in toluene
(phenyl C), 145.3 (phenyl C), 145.1 (d, JP–C = 42.2 Hz, phenyl (15 mL) at room temperature and recrystallization from an
C), 143.4 (phenyl C), 141.9 (phenyl C), 139.3 (phenyl C), 129.9 n-hexane solution by a similar procedure as that in the syn-
(phenyl C), 128.7 (ring C), 128.5 (ring C), 120.2 (d, JP–C
=
thesis of 3. Yield: 145 mg (73%) (Found: C, 60.48; H, 8.34.
3.4 Hz, ring C), 118.6 (ring C), 116.0 (ring C), 38.7 (PhCH3), C40H66OTh requires C, 60.43; H, 8.37%). M.p.: 167–169 °C
35.1 (C(CH3)3 and C(CH3)3), 34.9 (C(CH3)3 and C(CH3)3), 34.3 (dec.). 1H NMR (C6D6): δ 6.58 (s, 1H, ring CH), 6.17 (m, 2H,
(C(CH3)3), 34.0 (C(CH3)3 and C(CH3)3), 33.4 (C(CH3)3), 32.1 ring CH), 5.73 (d, J = 3.0 Hz, 1H, ring CH), 4.85 (s, 1H, CvCH),
(C(CH3)3), 31.9 (CH2), 23.0 (CH2), 21.3 (C(CH3)3), 14.3 2.12 (m, 4H, CH2), 1.68 (s, 3H, CH3), 1.68 (m, 5H, CH2 and
(CH2CH3) ppm. 31P{1H} NMR (C6D6):
δ −18.9 ppm. IR CH3), 1.56 (s, 9H, C(CH3)3), 1.52 (s, 9H, C(CH3)3), 1.48 (s, 20H,
(KBr, cm−1): ν 2959 (s), 2922 (s), 2906 (s), 2868 (s), 1612 (s), C(CH3)3 and CH2), 1.36 (s, 9H, C(CH3)3), 0.52 (d, J = 13.0 Hz,
1587 (s), 1564 (s), 1479 (s), 1460 (s), 1390 (s), 1359 (s), 1238 (s), 1H, ThCH2), −0.01 (d, J = 13.0 Hz, 1H, ThCH2) ppm. 13C{1H}
1020 (m), 827 (s).
NMR (C6D6): δ 159.8 (ring C), 142.7 (ring C), 141.8 (ring C),
Method B. NMR scale. A C6D6 (0.3 mL) solution of 140.4 (ring C), 140.0 (ring C), 139.6 (ring C), 125.8 (ring C),
(p-tolyl)2CvNH (4.2 mg, 0.02 mmol) was slowly added to 117.8 (ring C), 115.5 (ring C), 115.2 (ring C), 112.7 (CvCO),
a
J. Young NMR tube charged with [η5-1,2,4- 101.9 (CvCO), 51.0 (ThCH2), 35.2 (C(CH3)2), 34.9 (C(CH3)3),
(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2; 20 mg, 0.02 mmol) 34.8 (C(CH3)3), 34.4 (C(CH3)3), 34.2 (C(CH3)2), 34.1 (C(CH3)2),
1
and C6D6 (0.2 mL). Resonances of 6 were observed by H NMR 34.0 (C(CH3)3), 33.4 (C(CH3)3), 33.4 (C(CH3)3), 33.0 (C(CH3)3),
spectroscopy (100% conversion) after the sample was stored at 32.8 (C(CH3)3), 31.9 (C(CH3)3), 31.5 (C(CH3)3), 31.4 (CH2), 24.1
room temperature overnight.
(CH2), 23.8 (CH2), 23.1 (CH2) ppm. IR (KBr, cm−1): ν 2958 (s),
Preparation of [η5-1,2,4-(Me3C)3C5H2]2Th(PH-2,4,6-tBu3C6H2) 2868 (s), 1467 (s), 1394 (s), 1361 (s), 1238 (s), 1095 (s), 1024 (s),
(κ-O-1-OC9H7) (7). Method A. This compound was obtained 810 (s).
as orange microcrystals from the reaction of [η5-1,2,4-
Method B. NMR scale. A C6D6 (0.3 mL) solution of cyclo-
(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2; 244 mg, 0.25 mmol) hexanone (2.0 mg, 0.02 mmol) was slowly added to a J. Young
and 1-indanone (33 mg, 0.25 mmol) in toluene (15 mL) at NMR tube charged with
[η5-1,2,4-(Me3C)3C5H2]2
room temperature and recrystallization from an n-hexane solu- ThvP-2,4,6-tBu3C6H2 (2; 20 mg, 0.02 mmol) and C6D6
tion by a similar procedure as that in the synthesis of 3. Yield: (0.2 mL). Resonances of
and 2,4,6-tBu3C6H2PH2 were
8
1
227 mg (82%) (Found: C, 66.14; H, 8.67. C61H95OPTh requires observed by H NMR spectroscopy (100% conversion) after the
C, 66.16; H, 8.65%). M.p.: 85–87 °C (dec.). 1H NMR (C6D6): sample was stored at room temperature overnight.
δ 8.12 (d, J = 7.2 Hz, 1H, phenyl), 7.51 (d, J = 1.8 Hz, 2H,
Preparation of [η5-1,2,4-(Me3C)3C5H2][η5,κ-C-1,2-(Me3C)2-4-
phenyl), 7.43 (t, J = 7.3 Hz, 1H, phenyl), 7.27 (d, J = 7.2 Hz, 1H, (CH2CMe2)C5H2]Th(κ-O,C-OPMe2CH2) (9). Method A. This
phenyl), 6.90 (m, 1H, phenyl), 6.72 (s, 2H, ring CH), 6.63 (s, compound was obtained as colourless crystals from the
2H, ring CH), 5.79 (s, 1H, ThOCvCH), 4.74 (d, JP–H = 218.1 Hz, reaction of [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2;
1H, ThPH), 3.28 (s, 2H, CH2), 1.93 (s, 18H, C(CH3)3), 1.48 (s, 244 mg, 0.25 mmol) and Me3PO (23 mg, 0.25 mmol) in
18H, C(CH3)3), 1.44 (s, 9H, C(CH3)3), 1.43 (s, 18H, C(CH3)3), toluene (15 mL) at room temperature and recrystallization
1.36 (s, 18H, C(CH3)3) ppm. 13C{1H} NMR (C6D6): δ 164.3 from an n-hexane solution by a similar procedure as that in
(ThOCvCH), 152.2 (d, JP–C = 3.7 Hz, phenyl C), 148.2 (phenyl the synthesis of 3. Yield: 138 mg (70%) (Found: C, 56.38; H,
C), 147.0 (phenyl C), 146.3 (phenyl C), 145.0 (phenyl C), 143.2 8.27. C37H65OPTh requires C, 56.33; H, 8.30%). M.p.:
(phenyl C), 142.9 (d, JP–C = 65.5 Hz, phenyl C), 142.2 (phenyl 148–150 °C (dec.). 1H NMR (C6D6): δ 6.14 (d, J = 3.0 Hz, 1H,
C), 125.6 (phenyl C), 125.2 (phenyl C), 124.3 (ring C), 120.8 ring CH), 6.00 (d, J = 3.2 Hz, 1H, ring CH), 5.96 (d, J = 3.0 Hz,
(ring C), 120.7 (ring C), 120.6 (ring C), 119.7 (ring C), 117.5 1H, ring CH), 5.78 (d, J = 3.2 Hz, 1H, ring CH), 1.70 (s, 3H,
(CvCH), 109.2 (CH2), 38.8 (C(CH3)3), 35.3 (C(CH3)3), 35.3 CH3), 1.61 (s, 18H, C(CH3)3), 1.60 (s, 9H, C(CH3)3), 1.55 (s, 12H,
(C(CH3)3), 35.1 (C(CH3)3), 34.5 (C(CH3)3), 34.1 (C(CH3)3), 34.1 C(CH3)3 and CH3), 1.33 (s, 9H, C(CH3)3), 1.06 (d, JP–H
=
(C(CH3)3), 33.1 (C(CH3)3), 32.0 (C(CH3)3), 27.0 (C(CH3)3) ppm. 12.0 Hz, 3H, PCH3), 0.98 (d, JP–H = 12.2 Hz, 3H, PCH3), 0.71 (br
31P{1H} NMR (C6D6): δ 5.0 ppm. IR (KBr, cm−1): ν 2958 (s), s, 2H, PCH2), 0.65 (d, J = 12.0 Hz, 1H, ThCH2), −0.70 (d, J =
2906 (s), 2870 (s), 1595 (s), 1568 (s), 1477 (s), 1460 (s), 1388 (s), 12.0 Hz, 1H, ThCH2) ppm. 13C{1H} NMR (C6D6): δ 141.1 (ring
1361 (s), 1240 (s), 1178 (s), 1120 (s), 1076 (s), 1020 (s), 785 (s).
C), 140.9 (ring C), 139.8 (ring C), 139.5 (ring C), 138.7 (ring C),
Method B. NMR scale. A C6D6 (0.3 mL) solution of 1-inda- 122.3 (ring C), 111.9 (ring C), 111.8 (ring C), 111.5 (ring C),
none (2.6 mg, 0.02 mmol) was slowly added to a J. Young 110.7 (ring C), 67.4 (d, JP–C = 9.8 Hz, ThCH2), 38.0 (C(CH3)2),
NMR
tube
charged
with
[η5-1,2,4-(Me3C)3C5H2]2 35.3 (C(CH3)3), 35.1 (C(CH3)3), 35.0 (C(CH3)3), 34.9 (C(CH3)3),
ThvP-2,4,6-tBu3C6H2 (2; 20 mg, 0.02 mmol) and C6D6 34.5 (C(CH3)3), 34.4 (C(CH3)3), 34.0 (C(CH3)3), 33.6 (C(CH3)3),
(0.2 mL). Resonances of 7 were observed by 1H NMR spec- 33.3 (C(CH3)3), 33.0 (C(CH3)3), 32.6 (C(CH3)2), 30.3 (C(CH3)2),
troscopy (100% conversion in 2 h).
22.6 (d, JP–C = 58.4 Hz, PCH2), 18.9 (d, JP–C = 60.5 Hz, P(CH3)2),
Preparation of [η5-1,2,4-(Me3C)3C5H2][η5,κ-C-1,2-(Me3C)2-4- 18.1 (d, JP–C = 62.3 Hz, P(CH3)2) ppm. 31P{1H} NMR (C6D6):
(CH2CMe2)C5H2]Th(κ-O-1-OC6H9) (8). Method A. This com- δ 57.3 ppm. IR (KBr, cm−1): ν 2958 (s), 2904 (s), 2868 (s), 1460 (s),
pound was obtained as colourless crystals from the reaction of 1386 (s), 1359 (s), 1259 (s), 1240 (s), 1103 (s), 1018 (s), 802 (s).
Dalton Trans.
This journal is © The Royal Society of Chemistry 2019

View Article Online
Dalton Transactions
Paper
Method B. NMR scale. A C6D6 (0.3 mL) solution of Me3PO NMR
tube
charged
with
[η5-1,2,4-(Me3C)3C5H2]2
(1.9 mg, 0.02 mmol) was slowly added to a J. Young NMR tube ThvP-2,4,6-tBu3C6H2 (2; 20 mg, 0.02 mmol) and C6D6
charged with [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2; (0.2 mL). H NMR resonances of 11 and of 2,4,6-tBu3C6H2PH2
1
20 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 9 and were observed (100% conversion) after the sample was stored
2,4,6-tBu3C6H2PH2 were observed by 1H NMR spectroscopy at room temperature overnight.
(100% conversion) after the sample was stored at room temp-
erature overnight.
Reaction of [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2)
with 1-methylimidazole. NMR scale. A C6D6 (0.2 mL) solution
Preparation of [η5-1,2,4-(Me3C)3C5H2]2Th(PH-2,4,6-tBu3C6H2) of 1-methylimidazole (1.6 mg, 0.02 mmol) was slowly added to
(C3H2NS) (10). Method A. This compound was obtained
a
J. Young NMR tube charged with [η5-1,2,4-(Me3C)3
as orange microcrystals from the reaction of [η5-1,2,4- C5H2]2ThvP-2,4,6-tBu3C6H2 (2; 20 mg, 0.02 mmol) and C6D6
(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2; 244 mg, 0.25 mmol) (0.3 mL). 1H NMR resonances of 11 besides those of unreacted
and thiazole (22 mg, 0.25 mmol) in toluene (15 mL) at room 2 and 2,4,6-tBu3C6H2PH2 were detected (50% conversion based
temperature and recrystallization from an n-hexane solution by on 2) after the sample was stored at room temperature overnight.
a similar procedure as that in the synthesis of 3. Yield: 225 mg
Preparation of [η5-1,2,4-(Me3C)3C5H2]2ThvN(p-tolyl) (12).
(85%) (Found: C, 62.28; H, 8.57; N, 1.30. C55H90NPSTh requires Method A. This compound was obtained as colourless
C, 62.30; H, 8.55; N, 1.32%). M.p.: 78–80 °C (dec.). 1H NMR microcrystals from the reaction of [η5-1,2,4-(Me3C)3C5H2]2
(C6D6): δ 7.77 (d, J = 2.7 Hz, 1H, thiazolyl), 7.51 (s, 2H, phenyl), ThvP-2,4,6-tBu3C6H2 (2; 244 mg, 0.25 mmol) and p-toluidine
7.45 (d, J = 2.7 Hz, 1H, thiazolyl), 6.55 (s, 2H, ring CH), 6.29 (d, (26 mg, 0.25 mmol) in toluene (15 mL) at room temperature
J = 4.4 Hz, 2H, ring CH), 4.57 (d, JP–H = 214.4 Hz, 1H, ThPH), and recrystallization from a benzene solution by a similar pro-
1
1.97 (s, 18H, C(CH3)3), 1.46 (s, 9H, C(CH3)3), 1.40 (s, 18H, cedure as that in the synthesis of 3. Yield: 167 mg (83%). H
C(CH3)3), 1.31 (s, 18H, C(CH3)3), 1.25 (s, 18H, C(CH3)3) ppm. NMR (C6D6): δ 7.12 (d, J = 8.0 Hz, 2H, aryl), 6.52 (s, 4H, ring
13C{1H} NMR (C6D6): δ 239.1 (d, JP–C = 5.4 Hz, ThCvN), 151.7 CH), 6.48 (d, J = 8.0 Hz, 2H, aryl), 2.33 (s, 3H, tolylCH3), 1.52
(d, JP–C = 4.5 Hz, aryl C), 145.9 (aryl C), 145.3 (d, JP–C = 54.0 Hz, (s, 36H, C(CH3)3), 1.44 (s, 18H, C(CH3)3). These spectroscopic
phenyl C), 143.9 (aryl C), 138.5 (aryl C), 132.6 (aryl C), 121.6 data agreed with those reported in the literature.8c,d,15
(ring C), 120.5 (d, JP–C = 4.7 Hz, ring C), 118.8 (ring C), 116.1
Method B. NMR scale. A C6D6 (0.3 mL) solution of p-tolui-
(ring C), 113.7 (ring C), 38.8 (C(CH3)3), 35.0 (C(CH3)3), 34.9 dine (2.1 mg, 0.02 mmol) was slowly added to a J. Young
(C(CH3)3), 34.8 (C(CH3)3), 34.7 (C(CH3)3), 34.4 (d, JP–C
=
NMR
tube
charged
with
[η5-1,2,4-(Me3C)3C5H2]2
54.0 Hz, C(CH3)3), 33.9 (C(CH3)3), 33.9 (C(CH3)3), 33.3 ThvP-2,4,6-tBu3C6H2 (2; 20 mg, 0.02 mmol) and C6D6
(C(CH3)3), 32.1 (C(CH3)3) ppm. 31P{1H} NMR (C6D6): δ −10.5 ppm. (0.2 mL). Resonances of 12 along with those of
IR (KBr, cm−1): ν 2958 (s), 2906 (s), 2868 (s), 1591 (s), 1477 (s), 2,4,6-tBu3C6H2PH2 were observed by 1H NMR spectroscopy
1460 (s), 1388 (s), 1359 (s), 1238 (s), 1105 (s), 1022 (s), 829 (s).
(100% conversion) after the sample was stored at room temp-
Method B. NMR scale. A C6D6 (0.3 mL) solution of thiazole erature overnight.
(1.7 mg, 0.02 mmol) was slowly added to a J. Young NMR tube
charged with [η5-1,2,4-(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2;
X-ray crystallography
20 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 10 were
observed by H NMR spectroscopy (100% conversion) after the
sample was stored at room temperature overnight.
Single-crystal X-ray diffraction measurements were carried out
1
on a Bruker Smart APEX II CCD or on a Rigaku Saturn CCD
diffractometer at 100(2) K using Mo Kα radiation (λ =
0.71073 Å) or Cu Kα radiation (λ = 1.54184 Å). For empirical
absorption correction the SADABS program was used.16 All
structures were solved by direct methods and refined by full-
matrix least squares on F2 employing the SHELXL program
package.17 Hydrogen atoms were geometrically fixed using the
riding model. The crystal data and experimental data for 3–6,
8–9 and 11 are summarised in the ESI.† Selected bond dis-
tances and angles are listed in Table 1.
Preparation of [η5-1,2,4-(Me3C)3C5H2]2Th[2-(1-MeC3H2N2)]2
(11). Method A. This compound was obtained as
colourless crystals from the reaction of [η5-1,2,4-
(Me3C)3C5H2]2ThvP-2,4,6-tBu3C6H2 (2; 244 mg, 0.25 mmol)
and 1-methylimidazole (41 mg, 0.50 mmol) in toluene (15 mL)
at room temperature and recrystallization from an n-hexane
solution by a similar procedure as that in the synthesis of 3.
Yield: 168 mg (78%) (Found: C, 58.61; H, 7.95; N, 6.54.
C42H68N4Th requires C, 58.59; H, 7.96; N, 6.51%). M.p.:
>300 °C (dec.). 1H NMR (C6D6): δ 7.01 (s, 4H, ring CH), 6.13 (br
s, 4H, imidazolyl), 3.32 (s, 6H, NCH3), 1.65 (s, 18H, C(CH3)3),
1.16 (s, 36H, C(CH3)3) ppm. 13C{1H} NMR (C6D6): δ 204.5
(ThC), 138.9 (CHvCH), 136.4 (ring C), 125.3 (ring C), 122.3
(ring C), 114.8 (CHvCH), 38.1 (C(CH3)3), 35.5 (C(CH3)3), 34.8
(C(CH3)3), 34.0 (NCH3), 33.5 (C(CH3)3) ppm. IR (KBr, cm−1): ν
2953 (s), 2902 (s), 1458 (s), 1388 (s), 1240 (s), 1099 (s), 1018 (s),
837 (s).
Conflicts of interest
There are no conflicts to declare.
Acknowledgements
Method B. NMR scale. A C6D6 (0.3 mL) solution of 1-methyl- This work was supported by the National Natural Science
imidazole (3.3 mg, 0.04 mmol) was slowly added to a J. Young Foundation of China (Grant No. 21871029, 21472013,
This journal is © The Royal Society of Chemistry 2019
Dalton Trans.

View Article Online
Paper
Dalton Transactions
21672024), and the Deutsche Forschungsgemeinschaft (DFG)
through the Heisenberg program (WA 2513/6 and WA 2513/8).
K. A. Udachin and A. J. Carty, Organometallics, 2001, 20,
2657–2659; (d) A. T. Termaten, T. Nijbacker, M. Schakel,
M. Lutz, A. L. Spek and K. Lammertsma, Organometallics,
2002, 21, 3196–3202; (e) R. Melenkivitz, D. J. Mindiola and
G. L. Hillhouse, J. Am. Chem. Soc., 2002, 124, 3846–3847;
(f) A. W. Ehlers, E. J. Baerends and K. Lammertsma, J. Am.
Chem. Soc., 2002, 124, 2831–2838; (g) A. T. Termaten,
M. Schakel, A. W. Ehlers, M. Lutz, A. L. Spek and
K. Lammertsma, Chem. – Eur. J., 2003, 9, 3577–3582;
(h) A. T. Termaten, T. Nijbacker, M. Schakel, M. Lutz,
A. L. Spek and K. Lammertsma, Chem. – Eur. J., 2003, 9,
2200–2208; (i) A. T. Termaten, H. Aktas, M. Schakel,
A. W. Ehlers, M. Lutz, A. L. Spek and K. Lammertsma,
Organometallics, 2003, 22, 1827–1834; (j) B. T. Sterenberg,
K. A. Udachin and A. J. Carty, Organometallics, 2003, 22,
3927–3932; (k) J. Sánchez-Nieves, B. T. Sterenberg,
K. A. Udachin and A. J. Carty, J. Am. Chem. Soc., 2003, 125,
2404–2405; (l) B. T. Sterenberg, O. S. Senturk, K. A. Udachin
and A. J. Carty, Organometallics, 2007, 26, 925–937;
(m) R. Renye-Biyogo, F. Delpech, A. Castel, V. Pimienta,
H. Gornitzka and P. Rivière, Organometallics, 2007, 26, 5091–
5101; (n) H. Aktas, J. C. Slootweg, A. W. Ehlers, M. Lutz,
A. L. Spek and K. Lammertsma, Organometallics, 2009, 28,
5166–5172; (o) H. Aktas, J. C. Slootweg, M. Schakel,
A. W. Ehlers, M. Lutz, A. L. Spek and K. Lammertsma, J. Am.
Chem. Soc., 2009, 131, 6666–6667.
4 The synthesis of the terminal phosphinidene complexes of
rare earth metals (Sc, Y, and lanthanide metals) has not
been achieved so far; only a handful of rare-earth metal
complexes with phosphinidene bridges have recently been
reported. For selected papers, see: (a) J. D. Masuda,
K. C. Jantunen, O. V. Ozerov, K. J. T. Noonan, D. P. Gates,
B. L. Scott and J. L. Kiplinger, J. Am. Chem. Soc., 2008, 130,
2408–2409; (b) P. Cui, Y. Chen, X. Xu and J. Sun, Chem.
Commun., 2008, 5547–5549; (c) B. F. Wicker, J. Scott,
J. G. Andino, X. Gao, H. Park, M. Pink and D. J. Mindiola,
J. Am. Chem. Soc., 2010, 132, 3691–3693; (d) P. Cui, Y. Chen
and M. V. Borzov, Dalton Trans., 2010, 39, 6886–6890;
(e) Y. Lv, X. Xu, Y. Chen, X. Leng and M. V. Borzov, Angew.
Chem., Int. Ed., 2011, 50, 11227–11229; (f) Y. Lv,
C. E. Kefalidis, J. Zhou, L. Maron, X. Leng and Y. Chen,
J. Am. Chem. Soc., 2013, 135, 14784–14796; (g) K. Wang,
G. Luo, J. Hong, X. Zhou, L. Weng, Y. Luo and L. Zhang,
Angew. Chem., Int. Ed., 2014, 53, 1053–1056; (h) T. Pugh,
F. Tuna, L. Ungur, D. Collison, E. J. L. McInnes,
L. F. Chibotaru and R. A. Layfield, Nat. Commun., 2015, 6,
7492; (i) J. Zhou, T. Li, L. Maron, X. Leng and Y. Chen,
Organometallics, 2015, 34, 470–476; ( j) J. Zhou, L. Xiang,
J. Guo, X. Leng and Y. Chen, Chem. – Eur. J., 2017, 23,
5424–5428.
Notes and references
1 For selected reviews, see: (a) A. H. Cowley, Acc. Chem. Res.,
1997, 30, 445–451; (b) D. W. Stephan, Angew. Chem., Int.
Ed., 2000, 39, 314–329; (c) F. Mathey, Angew. Chem., Int. Ed.,
2003, 42, 1578–1604; (d) S. Greenberg and D. W. Stephan,
Chem. Soc. Rev., 2008, 37, 1482–1489; (e) R. Waterman,
Dalton Trans., 2009, 18–26; (f) L. Weber, Eur. J. Inorg.
Chem., 2007, 4095–4117; (g) H. Aktas, J. C. Slootweg and
K. Lammertsma, Angew. Chem., Int. Ed., 2010, 49, 2102–
2113; (h) M. E. García, D. García-Vivó, A. Ramos and
M. A. Ruiz, Coord. Chem. Rev., 2017, 330, 1–36.
2 Selected papers on groups 4 and 5 metal phosphinidene
complexes, see: (a) Z. Hou and D. W. Stephan, J. Am. Chem.
Soc., 1992, 114, 10088–10089; (b) C. C. Cummins,
R. R. Schrock and W. M. Davis, Angew. Chem., Int. Ed. Engl.,
1993, 32, 756–759; (c) Z. Hou, T. L. Breen and
D. W. Stephan, Organometallics, 1993, 12, 3158–3167;
(d) J. Ho, R. Rousseau and D. W. Stephan, Organometallics,
1994, 13, 1918–1926; (e) J. B. Bonanno, P. T. Wolczanski
and E. B. Lobkovsky, J. Am. Chem. Soc., 1994, 116, 11159–
11160; (f) T. L. Breen and D. W. Stephan, J. Am. Chem. Soc.,
1995, 117, 11914–11921; (g) E. Urnezius, K.-C. Lam,
A. L. Rheingold and J. D. Protasiewicz, J. Organomet. Chem.,
2001, 630, 193–197; (h) F. Basuli, J. Tomaszewski,
J. C. Huffman and D. J. Mindiola, J. Am. Chem. Soc., 2003,
125, 10170–10171; (i) F. Basuli, B. C. Bailey, J. C. Huffman,
M.-H. Baik and D. J. Mindiola, J. Am. Chem. Soc., 2004, 126,
1924–1925; ( j) B. C. Bailey, J. C. Huffman, D. J. Mindiola,
W. Weng and O. V. Ozerov, Organometallics, 2005, 24, 1390–
1393; (k) G. Zhao, F. Basuli, U. J. Kilgore, H. Fan,
H. Aneetha, J. C. Huffman, G. Wu and D. J. Mindiola,
J. Am. Chem. Soc., 2006, 128, 13575–13585; (l) U. J. Kilgore,
H. Fan, M. Pink, E. Urnezius, J. D. Protasiewicz and
D. J. Mindiola, Chem. Commun., 2009, 4521–4523;
(m) R. Waterman and T. D. Tilley, Chem. Sci., 2011, 2, 1320–
1325; (n) T. W. Graham, K. A. Udachin, M. Z. Zgierski and
A. J. Carty, Organometallics, 2011, 30, 1382–1388;
(o) M. A. Rankin and C. C. Cummins, Dalton Trans., 2012,
41, 9615–9618; (p) K. Searles, P. J. Carroll and
D. J. Mindiola, Organometallics, 2015, 34, 4641–4643;
(q) A. T. Normand, C. G. Daniliuc, B. Wibbeling, G. Kehr,
P. Le Gendre and G. Erker, J. Am. Chem. Soc., 2015, 137,
10796–10808; (r) L. Andrews and H.-G. Cho, Inorg. Chem.,
2016, 55, 8786–8793; (s) H. Stafford, T. M. Rookes,
E. P. Wildman, G. Balázs, A. J. Wooles, M. Scheer and
S. T. Liddle, Angew. Chem., Int. Ed., 2017, 56, 7669–7673.
3 Selected papers on other d-transition metal phosphinidene
complexes, see: (a) P. B. Hitchcock, M. F. Lappert and
W.-P. Leung, J. Chem. Soc., Chem. Commun., 1987, 1282–
1283; (b) B. T. Sterenberg, K. A. Udachin and A. J. Carty,
Organometallics, 2001, 20, 4463–4465; (c) B. T. Sterenberg,
5 (a) M. R. Duttera, V. W. Day and T. J. Marks, J. Am. Chem.
Soc., 1984, 106, 2907–2912; (b) D. S. J. Arney,
R. C. Schnabel, B. C. Scott and C. J. Burns, J. Am. Chem.
Soc., 1996, 118, 6780–6781; (c) B. M. Gardner, G. Balázs,
M. Scheer, F. Tuna, E. J. L. McInnes, J. McMaster, W. Lewis,
A. J. Blake and S. T. Liddle, Angew. Chem., Int. Ed., 2014, 53,
Dalton Trans.
This journal is © The Royal Society of Chemistry 2019

View Article Online
Dalton Transactions
Paper
4484–4488; (d) A. C. Behrle, L. Castro, L. Maron and
J. R. Walensky, J. Am. Chem. Soc., 2015, 137, 14846–14849;
(e) E. P. Wildman, G. Balázs, A. J. Wooles, M. Scheer and
S. T. Liddle, Nat. Commun., 2016, 7, 12884;
(f) T. M. Rookes, B. M. Gardner, G. Balázs, M. Gregson,
F. Tuna, A. J. Wooles, M. Scheer and S. T. Liddle, Angew.
Chem., Int. Ed., 2017, 56, 10495–10500; (g) S. P. Vilanova,
P. Alayoglu, M. Heidarian, P. Huang and J. R. Walensky,
Chem. – Eur. J., 2017, 23, 16748–16752.
L. Maron, W. Lewis, A. J. Blake and S. T. Liddle, Chem. Sci.,
2014, 5, 2489–2497; ( j) B. Fang, W. Ren, G. Hou, G. Zi,
D.-C. Fang, L. Maron and M. D. Walter, J. Am. Chem. Soc.,
2014, 136, 17249–17261; (k) B. Fang, G. Hou, G. Zi,
D.-C. Fang and M. D. Walter, Dalton Trans., 2015, 44, 7927–
7934; (l) B. Fang, L. Zhang, G. Hou, G. Zi, D.-C. Fang and
M. D. Walter, Organometallics, 2015, 34, 5669–5681;
(m) N. L. Bell, L. Maron and P. L. Arnold, J. Am. Chem. Soc.,
2015, 137, 10492–10495; (n) D. E. Smiles, G. Wu,
P. Hrobárik and T. W. Hayton, J. Am. Chem. Soc., 2016, 138,
814–825; (o) K. P. Browne, K. A. Maerzke, N. E. Travia,
D. E. Morris, B. L. Scott, N. J. Henson, P. Yang,
J. L. Kiplinger and J. M. Veauthier, Inorg. Chem., 2016, 55,
4941–4950; (p) L. Zhang, G. Hou, G. Zi, W. Ding and
M. D. Walter, J. Am. Chem. Soc., 2016, 138, 5130–5142;
(q) L. Zhang, B. Fang, G. Hou, G. Zi, W. Ding and
M. D. Walter, Organometallics, 2017, 36, 898–910.
8 (a) G. Zi, L. Jia, E. L. Werkema, M. D. Walter,
J. P. Gottfriedsen and R. A. Andersen, Organometallics,
2005, 24, 4251–4264; (b) G. Zi, L. L. Blosch, L. Jia and
R. A. Andersen, Organometallics, 2005, 24, 4602–4612;
(c) W. Ren, G. Zi, D.-C. Fang and M. D. Walter, J. Am. Chem.
Soc., 2011, 133, 13183–13196; (d) W. Ren, G. Zi, D.-C. Fang
and M. D. Walter, Chem. – Eur. J., 2011, 17, 12669–12682;
(e) W. Ren, E. Zhou, B. Fang, G. Zi, D.-C. Fang and
M. D. Walter, Chem. Sci., 2014, 5, 3165–3172; (f) W. Ren,
E. Zhou, B. Fang, G. Hou, G. Zi, D.-C. Fang and
M. D. Walter, Angew. Chem., Int. Ed., 2014, 53, 11310–
11314; (g) E. Zhou, W. Ren, G. Hou, G. Zi, D.-C. Fang and
M. D. Walter, Organometallics, 2015, 34, 3637–3647;
(h) P. Yang, E. Zhou, G. Hou, G. Zi, W. Ding and
M. D. Walter, Chem. – Eur. J., 2016, 22, 13845–13849;
(i) C. Zhang, P. Yang, E. Zhou, X. Deng, G. Zi and
M. D. Walter, Organometallics, 2017, 36, 4525–4538.
6 For selected reviews on activation of small molecules by
organoactinides, see: (a) E. Barnea and M. S. Eisen, Coord.
Chem. Rev., 2006, 250, 855–899; (b) M. Ephritikhine, Dalton
Trans., 2006, 2501–2516; (c) O. T. Summerscales and
F. G. N. Cloke, Struct. Bonding, 2008, 127, 87–117;
(d) K. Meyer and S. C. Bart, Adv. Inorg. Chem., 2008, 60, 1–
30; (e) T. Andrea and M. S. Eisen, Chem. Soc. Rev., 2008, 37,
550–567; (f) A. R. Fox, S. C. Bart, K. Meyer and
C. C. Cummins, Nature, 2008, 455, 341–349; (g) O. P. Lam,
C. Anthon and K. Meyer, Dalton Trans., 2009, 9677–9691;
(h) M. S. Eisen, Top. Organomet. Chem., 2010, 31, 157–184;
(i) T. W. Hayton, Dalton Trans., 2010, 39, 1145–1158;
( j) O. P. Lam and K. Meyer, Angew. Chem., Int. Ed., 2011,
50, 9542–9544; (k) P. L. Arnold, Chem. Commun., 2011, 47,
9005–9010; (l) O. P. Lam and K. Meyer, Polyhedron, 2012,
32, 1–9; (m) K. R. D. Johnson and P. G. Hayes, Chem. Soc.
Rev., 2013, 42, 1947–1960; (n) M. Ephritikhine,
Organometallics, 2013, 32, 2464–2488; (o) T. W. Hayton,
Chem. Commun., 2013, 49, 2956–2973; (p) T. W. Hayton,
Nat. Chem., 2013, 5, 451–452; (q) B. M. Gardner and
S. T. Liddle, Eur. J. Inorg. Chem., 2013, 3753–3770; (r) G. Zi,
Sci. China: Chem., 2014, 57, 1064–1072; (s) H. S. La Pierre
and K. Meyer, Prog. Inorg. Chem., 2014, 58, 303–415;
(t) P. L. Arnold, M. W. McMullon, J. Rieb and F. E. Kühn,
Angew. Chem., Int. Ed., 2015, 54, 82–100; (u) S. T. Liddle,
Angew. Chem., Int. Ed., 2015, 54, 8604–8641; (v) F. Ortu,
A. Formanuik, J. R. Innes and D. P. Mills, Dalton Trans.,
9 C. Zhang, G. Hou, G. Zi, W. Ding and M. D. Walter, J. Am.
Chem. Soc., 2018, 140, 14511–14525.
2016, 45, 7537–7549; (w) M. Ephritikhine, Coord. Chem. 10 W. Ren, H. Song, G. Zi and M. D. Walter, Dalton Trans.,
Rev., 2016, 319, 35–62; (x) G. Zi, Chem. Commun., 2018, 54,
7412–7430.
7 Selected papers about the bonding of organoactinide com-
plexes, see: (a) N. Barros, D. Maynau, L. Maron,
O. Eisenstein, G. Zi and R. A. Andersen, Organometallics,
2007, 26, 5059–5065; (b) T. Cantat, C. R. Graves,
2012, 41, 5965–5973.
11 (a) W. J. Evans, J. R. Walensky and J. W. Ziller, Chem. – Eur.
J., 2009, 15, 12204–12207; (b) N. A. Siladke, C. L. Webster,
J. R. Walensky, M. K. Takase, J. W. Ziller, D. J. Grant,
L. Gagliardi and W. J. Evans, Organometallics, 2013, 32,
6522–6531.
K. C. Jantunen, C. J. Burns, B. L. Scott, E. J. Schelter, 12 C. Zhang, G. Hou, G. Zi, W. Ding and M. D. Walter, Inorg.
D. E. Morris, P. J. Hay and J. L. Kiplinger, J. Am. Chem. Soc., Chem., 2019, 58, 1571–1590.
2008, 130, 17537–17551; (c) A. Yahia and L. Maron, 13 J. Bresien, A. Schulz and A. Villinger, Dalton Trans., 2016,
Organometallics, 2009, 28, 672–679; (d) J. R. Walensky, 45, 498–501.
R. L. Martin, J. W. Ziller and W. J. Evans, Inorg. Chem., 14 G. W. Rabe, G. P. A. Yap and A. L. Rheingold, Inorg. Chem.,
2010, 49, 10007–10012; (e) W. Ren, X. Deng, G. Zi and 1997, 36, 1990–1991.
D.-C. Fang, Dalton Trans., 2011, 40, 9662–9664; 15 W. Ren, G. Zi and M. D. Walter, Organometallics, 2012, 31,
(f) L. A. Seaman, E. A. Pedrick, T. Tsuchiya, G. Wu, 672–679.
E. Jakubikova and T. W. Hayton, Angew. Chem., Int. Ed., 16 G. M. Sheldrick, SADABS, Program for Empirical Absorption
2013, 52, 10589–10592; (g) N. Kaltsoyannis, Inorg. Chem.,
2013, 52, 3407–3413; (h) M. L. Neidig, D. L. Clark and
Correction of Area Detector Data, University of Göttingen,
Göttingen, Germany, 1996.
R. L. Martin, Coord. Chem. Rev., 2013, 257, 394–406; 17 G. M. Sheldrick, Acta Crystallogr., Sect. A: Found.
(i) B. M. Gardner, P. A. Cleaves, C. E. Kefalidis, J. Fang,
Crystallogr., 2008, 64, 112–122.
This journal is © The Royal Society of Chemistry 2019
Dalton Trans.