Coordination properties of multidentate phosphanylborane ligands in tungsten nitrosyl complexes

Article abstract of DOI:10.1002/ejic.201201565

The ambiphilic and small-bite-angle diphosphanylborane ligands Ph ₂PCH(PPh₂)CH₂B(C₈H₁₄) (2) and Ph₂PCH₂CH[B(C₈H₁₄)]PPh ₂ (3) containing the Lewis acidic 9-boranorbornyl group B(C ₈H₁₄) have been prepared in one step by regioselective anti-Markovnikov hydroborations of 1,1-bis(diphenylphosphanyl)ethylene and 1,2-bis(diphenylphosphanyl)ethylene with 9-borabicyclo[3.3.1]nonane (9-BBN) under relatively drastic reaction condition. The coordination properties of Ph₂PCH₂CH₂B(C₈H₁₄) (1) and the newly prepared 2 and 3 towards the tungsten nitrosyl fragment {WNO} ⁶ have been studied structurally and spectroscopically. Herein, we report the cis and trans tungsten nitrosyl complexes cis-[W(CO) ₂(1)₂(NO)(Cl)] (cis-4a), cis-[W(CO)₂(1) ₂(NO)(H)] (cis-4b), trans-[W(CO)₂(1)₂(NO)(Cl)] (trans-4a), trans-[W(CO)₂(1)₂(NO)(H)] (trans-4b), cis-[W(CO)₂(2)(NO)(Cl)] (cis-5a), cis-[W(CO)₂(2)(NO)(H)] (cis-5b), cis-[W(CO)₂(3)(NO)(Cl)] (cis-6a), cis-[W(CO) ₂(3)(NO)(H)] (cis-6b), which were readily obtained from straightforward ligand-substitution reactions of the tungsten carbonyl nitrosyl precursor [W(NO)(CO)₄(ClAlCl₃)] in tetrahydrofuran. The crystal structures of the tungsten chloride complexes cis-4a, trans-4a, and cis-5a revealed that the trialkyl boron centers are free pendants in the secondary coordination spheres, whereas in the hydride complexes trans-4b, cis-5b, and cis-6b the hydride ligand trans to the nitrosyl ligand is σ coordinated to the tethered B(C₈H₁₄) group and form three-center, two-electron (3c-2e) W-H-B bonds, which were observed in their crystal structures. The authenticity of the 3c-2e W-H-B bond in the tungsten hydride complex cis-5b was further checked by a DFT structural optimization and natural bond order (NBO) analysis. The coordination properties of phosphanylborane ligands in newly synthesized tungsten carbonyl nitrosyl complexes are explored by multinuclear NMR and IR spectroscopy, single-crystal X-ray structure analyses, and DFT calculations. Copyright

Full text of DOI:10.1002/ejic.201201565

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Tungsten Phosphanylborane Complexes
R. Jana, O. Blacque, Y. Jiang,
H. Berke* ....................................... 1–13
The coordination properties of phosphan-
ylborane ligands in newly synthesized tung-
sten carbonyl nitrosyl complexes are ex-
plored by multinuclear NMR and IR spec-
troscopy, single-crystal X-ray structure
analyses, and DFT calculations.
Coordination Properties of Multidentate
Phosphanylborane Ligands in Tungsten
Nitrosyl Complexes
Keywords: Hydroboration / Lewis acidic
borane / Phosphanes / Hydride ligands /
Tungsten
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DOI:10.1002/ejic.201201565
Coordination Properties of Multidentate Phosphanylborane
Ligands in Tungsten Nitrosyl Complexes
Rajkumar Jana,[a] Olivier Blacque,[a] Yanfeng Jiang,[a] and
Heinz Berke*[a]
Keywords: Hydroboration / Lewis acidic borane / Phosphanes / Hydride ligands / Tungsten
The ambiphilic and small-bite-angle diphosphanylborane li-
gands Ph2PCH(PPh2)CH2B(C8H14 (2) and Ph2PCH2CH-
(3)(NO)(Cl)] (cis-6a), cis-[W(CO)2(3)(NO)(H)] (cis-6b), which
were readily obtained from straightforward ligand-substitu-
tion reactions of the tungsten carbonyl nitrosyl precursor
[W(NO)(CO)4(ClAlCl3)] in tetrahydrofuran. The crystal struc-
tures of the tungsten chloride complexes cis-4a, trans-4a, and
cis-5a revealed that the trialkyl boron centers are free pen-
dants in the secondary coordination spheres, whereas in the
hydride complexes trans-4b, cis-5b, and cis-6b the hydride
)
[B(C8H14)]PPh2 (3) containing the Lewis acidic 9-boranor-
bornyl group B(C8H14) have been prepared in one step by
regioselective anti-Markovnikov hydroborations of 1,1-bis-
(diphenylphosphanyl)ethylene and 1,2-bis(diphenylphos-
phanyl)ethylene with 9-borabicyclo[3.3.1]nonane (9-BBN)
under relatively drastic reaction condition. The coordination
properties of Ph2PCH2CH2B(C8H14) (1) and the newly pre- ligand trans to the nitrosyl ligand is σ coordinated to the teth-
pared 2 and 3 towards the tungsten nitrosyl fragment ered B(C8H14) group and form three-center, two-electron (3c–
{WNO}6 have been studied structurally and spectroscopi-
2e) W–H–B bonds, which were observed in their crystal
cally. Herein, we report the cis and trans tungsten nitrosyl structures. The authenticity of the 3c–2e W–H–B bond in the
complexes cis-[W(CO)2(1)2(NO)(Cl)] (cis-4a), cis-[W(CO)2(1)2-
(NO)(H)] (cis-4b), trans-[W(CO)2(1)2(NO)(Cl)] (trans-4a),
trans-[W(CO)2(1)2(NO)(H)] (trans-4b), cis-[W(CO)2(2)(NO)-
(Cl)] (cis-5a), cis-[W(CO)2(2)(NO)(H)] (cis-5b), cis-[W(CO)2-
tungsten hydride complex cis-5b was further checked by a
DFT structural optimization and natural bond order (NBO)
analysis.
plore various coordination modes,[11] tunable fluorescent
systems,[17] and photoisomerization.[18] The unique ambi-
philic properties of the PB ligand system arise because of
the co-existence of Lewis acidic and basic centers in close
proximity. The ambiphilic properties of PBs lead to interest-
ing structural and electronic features by virtue of the affin-
ity of the pendant Lewis acid to the other coligands or to
the metal centers in either an intramolecular or an intermo-
lecular manner.
In general, three possible coordination modes of PBs
(considering one phosphorus donor and one Lewis acid ac-
ceptor) are expected in a metal complex. The nucleophilic
phosphorus moiety can coordinate to metal centers, and
the Lewis acidic group can remain pendant or, alternatively,
interact with either a coligand or the metal center itself.
These ligand systems are of fundamental interests, because
the reactivity of the complex may be greatly influenced by
pendant groups attached to a coordinated ligand.[1]
Introduction
The potential of main-group Lewis acids to act as σ-
acceptor ligands has been exploited in many important
catalytic applications, for example, in Ziegler–Natta type
catalysts.[1–3] Weak metal–ligand interactions are often
found in both the primary and the secondary coordination
spheres of transition-metal complexes containing group 13
Lewis acids.[4–13] Among them, metalloboratranes[14] con-
taining tethered Lewis acidic borane groups are the most
studied systems. Recently, ambiphilic phosphanylborane
(PB) ligands, in which nucleophilic phosphorus and electro-
philic boron centers are attached by an organic spacer, have
attracted considerable interest in many important research
topics such as metal-free dihydrogen activation under ambi-
ent conditions,[15] small-molecule activation,[15,16] catalytic
hydrogenations,[15d] stoichiometric carbon monoxide hydro-
genations,[1] ligands for transition-metal complexes to ex-
To date, mostly, phosphanylboranes containing rigid aryl
spacers, such as o- and p-C6H4 groups have been studied,
in addition to a few examples[1,19] containing flexible alkyl
spacers. The promising role of flexible PBs in Lewis acid
assisted homogeneous CO hydrogenation, catalyzed by cat-
ionic Re and Mn carbonyl complexes, has been reported by
Bercaw and co-workers, and the ligands exhibit different
[a] Institute of Inorganic Chemistry, University of Zürich,
Winterthurerstrasse 190, 8057 Zürich, Switzerland
Fax: +41-44-6356802
E-mail: hberke@aci.unizh.ch
Homepage: http://www.aci.uzh.ch/en/research-groups/emeriti/
berke-group/prof-dr-heinz-berke/?tx_wfqbe_pi1
Supporting information for this article is available on the
WWW under http://dx.doi.org/10.1002/ejic.201201565.
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reduction chemistry under similar reaction conditions.[1] and the flexibility of the whole ligand). The pendant Lewis
However, the incorporation of phosphanylborane ligands in acidic boron center has the ability to be engaged in reac-
group 6 transition-metal complexes has not been studied to tions in the secondary sphere coordination.
date. The study of phosphanylborane coordination to group
6 metals has been realized mainly for two reasons. Firstly,
advances in non-precious-metal catalysis[20–22] have evi-
denced that Mo and W (cheap metals for noble tasks) cata-
Results and Discussion
lysts are potential candidates for various transformations.
Preparation of Multidentate Phosphanylborane Ligands
The other important reason is that the heteroleptic tungsten
Containing Lewis Acidic B(C8H14) Group
carbonyl nitrosyl fragments are expected to be well suited
for catalytic carbon monoxide hydrogenation, as it is also
isoelectronic and isostructural with cationic, homoleptic
MnI–CO and ReI–CO fragments, which are suitable candi-
dates for stoichiometric carbon monoxide hydrogenation.[1]
Tungsten hydride complexes of the type [W(H)(NO)-
(CO)n(L)4–n] (L = monodentate or bidentate phosphane li-
gands) were previously studied in our group for insertion
reactions to unsaturated organic molecules.[23] These hy-
dride complexes undergo insertion reactions by internal
transfer of the metal-bound hydridic H atom to the unsatu-
rated molecule. We also concluded that insertion reactions
are accelerated by the trans influence of the nitrosyl ligand,
which makes the W–H bond strongly hydridic and, conse-
quently, show an unusually high propensity to undergo
carbonyl migratory insertion. However, insertion reactions
may also take place without coordination of the substrate
molecule to the metal center, but then hydride transfer oc-
curs in the secondary coordination sphere. Thus, our pre-
vious results on tungsten hydride nitrosyl complexes
prompted us to explore phosphanylborane coordination to
the {WNO}6 fragment in search of potential candidates for
CO (internal hydride transfer) and CO2 (hydride transfer in
the secondary coordination sphere) reduction chemistry, in
which the Lewis acidic boron center(s) will activate both
the metal-bound CO ligand and exogenous CO2 separately
and stabilize the hydrogenated products. As part of our re-
search on Lewis acid cocatalyzed homogeneous hydrogen-
ations,[24] we prepared two new borane-attached bisphos-
phane ligands (ligands 2 and 3, Figure 1), which contain
both rigid and flexible spacers, to study their coordination
properties towards non-precious-metal fragments.
The monophosphanylborane ligand Ph2PCH2CH2B-
(C8H14), 1, was obtained from the reaction of diphenyl-
vinylphosphane with 9-borabicyclo[3.3.1]nonane (9-BBN)
in tetrahydrofuran (THF) at 60 °C by following a previously
reported literature procedure.[25] We have now prepared two
new bisphosphane analogues Ph2PCH(PPh2)CH2B(C8H14),
2, and Ph2PCH2CH[B(C8H14)]PPh2, 3, by straightforward
hydroboration of 1,1-bis(diphenylphosphanyl)ethylene and
1,2-bis(diphenylphosphanyl)ethylene, respectively, with 9-
BBN under relatively drastic reaction conditions
(Scheme 1). A THF solution containing an equimolar mix-
ture of 9-BBN (0.5 m solution in THF) and 1,1-bis(diphen-
ylphosphanyl)ethylene or 1,2-bis(diphenylphosphanyl)ethyl-
ene was heated at 120 °C in a sealed pressure vessel under
a N2 atmosphere for several days. According to in situ mon-
itoring by 31P{1H} NMR spectroscopy, both reactions were
complete within three days, and the desired ligands were
produced by anti-Markovnikov hydroboration without the
formation of any other side-products. The reactions of 1,1-
bis(diphenylphosphanyl)ethylene with 9-BBN was found to
be totally regioselective under the extreme reaction condi-
tions (additional preference for regioselective hydroboration
stems from the steric effects of gem-PPh2 groups). After
work-up and recrystallization procedures, the phosphanyl-
borane ligands 2 and 3 were obtained as colorless sub-
stances in 93 and 87% yields, respectively. The 31P{1H}
NMR spectrum of 2 showed a sharp singlet signal at δ =
2.69 ppm owing to the presence of two chemically equiva-
lent gem-PPh2 groups, and the 31P{1H} NMR resonance of
3 appeared as two doublets with unequal intensities at δ =
–10.63 (3JP,P = 32.4 Hz) and –9.97 ppm (3JP,P = 32.4 Hz)
resulting from two chemically nonequivalent vicinal PPh2
groups. The signal at δ = –10.63 ppm was assigned to the
–PPh2 moiety close to the B(C8H14) group, and the one at
δ = –9.97 ppm was assigned to the PPh2 group far from the
B(C8H14) moiety. Typical broad 11B NMR signals were also
observed at δ = 59.1 (for 2) and 85.6 ppm (for 3) as expected
for the trialkyl group B(C8H14). These two ligands are ex-
pected to have monomeric open structures based on their
Figure 1. Phosphanylborane ligands used in this work.
To identify metal–ligand interactions, especially those oc-
curring in the secondary coordination sphere, we recently
became interested in tungsten nitrosyl complexes contain-
ing multidentate PB ligands. Our results include investi-
gations of tungsten nitrosyl complexes of three different PB
ligands (1, 2, and 3), which vary in the nature of their or-
ganic linkers (distances between heteroatoms, bite angles, Scheme 1. Synthesis of phosphanylborane ligands 2 and 3.
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NMR spectroscopic data, which are very similar to those of when the reaction was performed at 70 °C for five minutes.
1.[25] Notably, the hydroboration of 1,2-bis(diphenylphos- A characteristic broad 11B NMR signal at δ = 42.7 ppm
phanyl)ethylene leads to the formation of a chiral center; confirmed the presence of a tricoordinated Lewis acidic
however, the stereoselectivity of the reaction was not deter- boron center B(C8H14) in the secondary coordination
mined. Both 2 and 3 contain two phosphorus donors, one sphere. Together with the multinuclear NMR spectroscopic
tethered electron-deficient boron group, a flexible and rigid data, two carbonyl stretching and vibration bands at 2016
backbone; they have small and relatively large bite angles, and 1937 cm–1 and one NO stretching band at 1619 cm–1 in
respectively. They also have the ability to chelate or bridge the FTIR spectrum clearly suggested that the major isomer
metal centers through the formation of chelate rings con- formed was cis-4a. A toluene solution of analytically pure
taining small or large P–M–P bite angles.
cis-4a was then heated at 70 °C in a sealed tube under a N2
atmosphere for several hours to obtain trans-4a. The up-
field shift of the characteristic 31P{1H} NMR signal to δ =
16.72 ppm, compared with δ = 8.90 ppm for cis-4a, and a
new 11B NMR signal at δ = 36.4 ppm suggested the forma-
tion of trans-4a, which was further supported by the ap-
Preparation of the Tungsten Nitrosyl Complexes cis-4a,
trans-4a, cis-5a, and cis-6a
The preparation of the phosphanylborane tungsten com- pearance of only one νCO stretching band at 1945 cm–1,
plexes cis-[W(CO)2(1)2(NO)(Cl)] (cis-4a), trans-[W(CO)2- consistent with the presence of two trans CO groups in an
(1)2(NO)(Cl)] (trans-4a), cis-[W(CO)2(2)(NO)(Cl)] (cis-5a), Oh environment. Yellow block and plate crystals of cis-4a
and cis-[W(CO)2(3)(NO)(Cl)] (cis-6a) was achieved by li- and trans-4a, respectively, were obtained from slow evapo-
gand-substitution reactions starting from the tungsten pre- ration of their respective pentane/THF solutions and were
cursor complex [W(CO)4(NO)(ClAlCl3)][26] and the corre- suitable for single-crystal X-ray diffraction studies. Thermal
sponding PB (Scheme 2). Several attempts to hydroborate ellipsoid plots of the crystal structures of cis-4a and trans-
the tungsten-coordinated phosphoethylene backbone to ob- 4a are presented in Figure 2. These two structures con-
tain analytically pure tungsten phosphanylborane com- firmed the formation of cis-4a in the initial course of the
plexes failed. However, the reaction of two equivalents of 1 reaction and the trans isomer was formed on prolonged
with one equivalent of [W(CO)4(NO)(ClAlCl3)] in THF at heating of the toluene solution of cis-4a. The interconver-
room temperature proceeds rapidly to give an isomeric mix- sion from the cis to the trans isomer was also supported by
ture of [W(CO)2(1)2(NO)(Cl)] (cis- and trans-4a) as ob- all the NMR and IR interpretations. Moreover, as expected,
served by multinuclear NMR and FTIR spectroscopy. The the crystal structures revealed that the Cl and NO ligands
31P{1H} NMR spectrum recorded in THF supports the co- remain trans to each other in both the cases; whereas, the
ordination of 1 to the W atom based on the appearance positions of the CO and the phosphane groups are inter-
of two upfield shifted singlet 31P resonances (δ = 8.90 and changed. The C1–O1 bond length of 1.134(3) Å in cis-4a is
16.72 ppm) along with characteristic W satellite peaks. One somewhat longer than that in trans-4a [C1–O1
=
of the isomers formed predominantly (cis-4a, 95% from in- 1.121(6) Å] and, as a consequence, a longer W–P bond
tegration of the 31P{1H} NMR signal at δ = 8.90 ppm) [2.559(1) Å] in cis-4a and shorter W–P bond length
Scheme 2. Synthesis of tungsten phosphanylborane complexes. a) THF, 70 °C, 5 min; b) toluene, 70 °C, 6 h; c) 2.2 equiv. of 1 m NaHBEt3
in toluene, toluene, 70 °C, 24 h; d) 2 equiv. of 1 m NaHBEt3 in toluene, toluene, –25 °C.
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Figure 2. Thermal ellipsoid plots of the crystal structures of cis-4a·THF and trans-4a. The THF molecule and all hydrogen atoms are
omitted for clarity.
[2.513(1) Å] in trans-4a were found. Both the trialkyl formed. The exact coordination mode of 2 was further es-
B(C8H14) groups in cis-4a and trans-4a were present as free tablished by X-ray crystallography. A thermal ellipsoid plot
pendants in their secondary coordination spheres without of the structure (shown in Figure 3) confirmed the small-
any intermolecular or intramolecular interactions.
bite-angle chelation of the ligand. The structural analysis
Under similar reaction conditions (THF, 70 °C), ligand showed that the unusual four-membered chelate is estab-
2 produced the expected complex cis-[W(CO)2(2)(NO)(Cl)] lished through the coordination of the two PPh2 groups;
(cis-5a) as a major product (90%) and a still unidentified this observation is in agreement with the appearance of only
minor product (10%) according to the 31P{1H} NMR spec- one singlet 31P{1H} NMR resonance at δ = 2.10 ppm. The
trum, which showed two singlet resonances along with typi- coordination of the nitrosyl, chloride, two CO, and phos-
cal tungsten satellite peaks at δ = 2.10 [1JP,W (satellites) = phanylborane ligands and the smaller P1–W1–P2 bite angle
212.2 Hz] and –11.68 [1JP,W (satellites) = 213.8 Hz] ppm. It (66.45°) and C1–W1–C2 [92.92(19)°], P2–W1–C2
was assumed that the latter signal arose from the presence [101.96(13)°], and P1–W–C1 [97.07(14)°] equatorial angles
of a dinuclear product formed from the coordination of two revealed a highly distorted octahedral geometry around the
PPh2 groups to two W centers. However, only the major W center. Also, the Lewis acidic trialkyl borane group
product was isolated and characterized. Similar to previous B(C8H14) behaves as a free pendant in the secondary coor-
observations, a broad 11B NMR signal was observed at δ = dination sphere in a similar way as it does in the crystal
86.8 ppm owing to the B(C8H14) group, and two carbonyl structures of cis-4a and trans-4a. Selected bond lengths and
bands at 2014 (vs, νCO) and 1934 cm–1 (vs, νCO) and one angles of all crystal structures are given in Table 1.
nitrosyl band at 1620 cm–1 (vs, νNO) were observed in the
When ligand 3 was treated with an equimolar quantity
FTIR spectrum. All these spectroscopic data undoubtedly
confirmed that a chelated tungsten PB complex had
of [W(CO)4(NO)(Cl)(AlCl3)] in THF, two diastereomers of
cis-[W(CO)2(3)(NO)(Cl)] (cis-6a) were formed in a 7:3 ratio
owing to the two possible stereochemical positions for the
NO and Cl ligands in the cis geometry with respect to the
chiral center in the phosphoethylene backbone. Owing to
their instability toward moisture and oxygen, these two iso-
mers could not be separated by column chromatography.
The isomeric mixture of cis-6a was analyzed by NMR spec-
troscopy. The 31P{1H} NMR signals of the major isomer
was found as two doublets at δ = 35.07 (3JP,P = 6.5 Hz,
1
1JP,W = 251.1 Hz) and 48.09 (3JP,P = 8.1 Hz, JP,W
=
244.6 Hz) ppm, and that of the minor isomer was also
1
found as two doublets at δ = 36.24 (3JP,P = 3.2 Hz, JP,W
=
252.7 Hz) and 53.21 (3JP,P = 1.6 Hz, 1JP,W = 246.2 Hz) ppm.
The infrared stretching frequencies were observed at 2015
(vs, νCO), 1938 (vs, νCO), and 1620 cm–1 (vs, νNO) and are
in accordance with the cis geometry in an octahedral coor-
dination environment. A broad 11B NMR singlet resonance
was found at δ = 84.9 ppm and corresponds to the
B(C8H14) group.
Figure 3. Thermal ellipsoid plot of the crystal structures of cis-5a.
All hydrogen atoms are omitted for clarity.
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Table 1. Selected bond lengths [Å] and angles [°] for the tungsten chloride complexes cis-4a, trans-4a, and cis-5a and the hydride complexes
trans-4b, cis-5b, and cis-6b.
W-chlorido complexes
P–W–P
–
O–N–W
N–O
C–O
C–O
–
W–Cl
W–P
W–P
–
cis-[W(CO)2(1)2(NO)(Cl)]
(cis-4a)
trans-[W(CO)2(1)2(NO)(Cl)]
(trans-4a)
cis-[W(CO)2(2)(NO)Cl]
(cis-5a)
O2–N1–W1
178.6(7)
O2–N1–W1
174(3)
O3–N1–W1
176.5(4)
N1–O2
1.205(8)
N1–O2
1.210(18)
N1–O3
1.177(5)
C1–O1
1.134(3)
C1–O1
1.121(6)
C1–O1
1.126(6)
W1–Cl1 W1–P1
2.430(3) 2.559(1)
W1–Cl1 W1–P1
2.428(5) 2.513(1)
W1–Cl1 W1–P1
–
–
–
P1–W–P2
66.5(3)
C2–O2
1.134(5)
W1–P2
2.470(1) 2.518(1) 2.596(1)
W-hydrido complexes
P–W–P
–
O–N–W
N–O
C–O
C–O
W–H
B–H
B–H–W
trans-[W(CO)2(1)2(NO)(H)]
(trans-4b)
cis-[W(CO)2(2)(NO)(H)]
(cis-5b)
O3–N1–W1
178.2(6)
N1–O3
1.208(7)
N1–O3
1.192(3)
N1–O3
1.191
N1–O3
1.196
N1–O1
1.189(11)
N1–O1
1.189
C1–O1
1.129(8)
C1–O1
1.133(3)
C1–O1
1.158
C1–O1
1.159
C1–O2
1.155(14)
C1–O2
1.158
C2–O2
1.131(9)
C2–O2
1.132(3)
C2–O2
1.158
C2–O2
1.159
C2–O3
1.049(13)
C2–O3
1.157
W1–H1
1.66(6)
W1–H1
1.84(3)
W1–H1
1.915
W1–H1
1.836
W1–H
2.08
B1–H1
1.60(6)
B1–H1
1.38(3)
B1–H1
1.403
B1–H1
5.408
B1–H
1.00
B1–H1–W1
149(4)
B1–H1–W1
156.2(17)
B1–H1–W1
157.16
P1–W1–P2 O3–N1–W1
65.1(2) 178.7(2)
P1–W1–P2 O3–N1–W1
65.31 178.82
P1–W1–P2 O3–N1–W1
67.40 178.92
P1–W1–P2 O1–N1–W1
75.7(1) 177.3(9)
P1–W1–P2 O1–N1–W1
75.22 178.9
cis-[W(CO)2(2)(NO)]
(H) (cis-5c) (DFT)[a]
cis-[W(CO)2(2)(NO)]
(H) (cis-5d) (DFT)[a]
cis-[W(CO)2(3)(NO)(H)]
(cis-6b)[b]
B1–H1–W1
155
B1–H1–W1
136.79
cis-[W(CO)2(4)(NO)(H)]
W1–H
1.953
B1–H
1.375
(cis-6b) (DFT)[a]
[a] Geometry parameters optimized by DFT calculations. [b] The structure was determined from a twinned crystal, and the hydride
ligand was located in a difference Fourier map. However its position could not be freely refined and, consequently, the bond parameters
associated with the hydridic H atom are not an accurate estimate.
Preparation of the Tungsten Hydride Complexes cis-4b,
trans-4b, cis-5b, and cis-6b
the coordination of the hydride ligand to the Lewis acidic
B(C8H14) group in trans-4b were established by X-ray crys-
tallography. The thermal ellipsoid plot of the obtained crys-
The treatment of the [W–Cl] complexes cis-4a, trans-4a, cis- tal structure is shown in Figure 4. One of the phenyl rings
5a, and cis-6a with excess NaHBEt3 produced the desired was found to be disordered over two positions with site-
hydride complexes cis-[W(CO)2(1)2(NO)(H)] (cis-4b), trans- occupancy factors of 0.43 and 0.57. The W center adopts
[W(CO)2(1)2(NO)(H)]
(trans-4b),
cis-[W(CO)2(2)- an idealized octahedral geometry and is coordinated to two
(NO)(H)] (cis-5b), and cis-[W(CO)2(3)(NO)(H)] (cis-6b). phosphorus atoms and hydride, nitrosyl, and two cis CO
The upfield-shifted 1H NMR resonances in the negative ligands in the primary coordination sphere. The hydride li-
ppm region evidence the presence of hydride ligands. All gand was located in a difference Fourier map and was freely
reactions were performed in Young NMR tubes under an refined with Uiso(H) = 1.2Ueq(W). Owing to its high stan-
inert atmosphere in deuterated toluene and were monitored dard deviations, the calculated W–H bond length of
1
by H and 31P{1H} NMR spectroscopy. To the best of our 1.66(6) Å is somewhat shorter than the bond lengths in
knowledge, no crystal structures of tungsten nitrosyl hy- [W(H)(CO)
(NO)(PMe3)3],[23b]
Mo(H)(CO)(NO)-
dride complexes containing multidentate chelating phos- (PMe3)3,[23c] and [W(H)(NO)(PMe3)4] [1.80(4), 1.84(3),
phanylborane ligands have been reported. We have system- 1.93(9) Å, respectively].[23a] The longer M–H bond lengths
atically performed the single-crystal X-ray structure deter- in the previously reported complexes could be qualitatively
mination of the hydride complexes trans-4b, cis-5b, and cis- attributed to the higher σ donor strength of the PMe3
6b. The reaction of cis-4a with NaHBEt3 at 70 °C initially groups compared to PPh2 groups. However, as expected,
produced the desired hydride complex cis-4b [δ(1H) = the hydride H atom was located trans to the nitrosyl group
–5.90 ppm for HW], which isomerized under the reaction with a slightly bent N1–W1–H axis [177(2)°]. Interestingly,
conditions to give solely the trans-hydride complex trans-4b it was found that one of the phosphanylborane ligands is
[δ(1H) = –6.27 ppm for HW]. However, trans-4b was also involved in a secondary sphere interaction through the σ
prepared from trans-4a under similar reaction conditions. coordination of the hydride ligand to one of the tethered
The 31P{1H} NMR spectrum showed a broad singlet reso- B(C8H14) groups, which results in the formation of a three-
nance with characteristic satellite peaks at δ = 24.43 ppm center, two-electron (3c–2e) W–H–B bond. This is one of
[1JP,W (satellites) = 344 Hz]. The broad resonance at δ = the examples in which the migration of the hydrogen atom
41.5 ppm in the 11B NMR spectrum was attributed to the from a Lewis acidic boron center to the metal center has
presence of two B(C8H14) groups. Two infrared bands were been observed and the hydrogen atom remained at the
found at 1946 (vs, νCO) and 1625 (vs, νNO) cm–1, but the metal center as a hydride species. The long B–H bond
stretching band associated with the W–H vibration could length of 1.60(6) Å (still shorter than the sum of the van
not be assigned owing to its weak intensity. The coordina- der Waals radii) indicated a weaker (C8H14)B···H interac-
tion behavior of two Ph2PCH2CH2B(C8H14) ligands and tion and stronger W–H interactions; this was further sup-
Eur. J. Inorg. Chem. 0000, 0–0
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Figure 4. Thermal ellipsoid plots of the molecular structures of trans-4b and cis-5b·0.5(C5H12). Solvent molecule and all hydrogen atoms
except the hydride ligand are omitted for clarity.
1
ported by the upfield shift of the H NMR resonance of very close to that found in the corresponding chloride com-
the hydride ligand to δ = –6.27 ppm. The other tethered plex cis-5a (66.45°).
B(C8H14) group is present as a free pendant in the second-
The reaction of cis-6a with two equivalents of NaHBEt3
ary coordination sphere.
was performed at –25 °C in toluene. A toluene solution of
The reaction of cis-5a with excess NaHBEt3 in toluene the complex was cooled inside a Young NMR tube and
at –25 °C immediately produced the desired hydride com- then titrated with NaHBEt3 solution (1 m in toluene), and
1
plex cis-5b. The upfield shifted H NMR resonance corre- the reaction was monitored by 1H and 31P{1H} NMR spec-
sponding to the HW atom was found at δ = –6.20 ppm as a troscopy. Upon completion, the reaction mixture showed a
1
broad triplet owing to the phosphorus couplings. The broad H NMR singlet at δ = –6.68 ppm, which indicates
31P{1H} NMR signal was observed at δ = 4.44 ppm, and the formation of a hydride complex. Following a work-up
the 11B NMR signal was observed at δ = 39.6 ppm. Strong procedure, the crude product was recrystallized from a
IR bands were found at 2015 and 1937 cm–1 for νCO and at pentane/toluene solution to afford yellow single crystals of
1627 cm–1 for νNO. A very weak hydride stretching band cis-6b suitable for single-crystal X-ray analysis. The crystal
associated with the W–H–B linkage made the assignment structure of cis-6b was determined from a twinned crystal,
difficult. The crystal structure of cis-5b shows that the ge- and the hydride was located in a difference Fourier map
ometry around the W center is highly distorted, which is (Figure 5). The position of HW could not be freely refined
probably because of the strong involvement of the B(C8H14) and, consequently, the bond parameters associated with HW
group in secondary sphere coordination to the hydridic H are not accurate. Nevertheless, the crystal structure shows
atom located trans to the NO group. The W–H bond length the presence of the expected secondary coordination sphere
of 1.84(3) Å compares well to those previously reported for interactions of a tethered boron center. Selected bond
analogous phosphane complexes.[28] The structure shows lengths and angles are summarized in Table 1.
that two P atoms (P1 and P2) are bent down [N1–W1–P1
= 103.21(7)° and N1–W1–P2 = 102.34(6)°] and displaced
by approximately 0.67 and 0.68 Å from the average equato-
rial plane created by the CO ligands and the W center to
facilitate a tridentate chelation involving P–W coordination
and coordination of the B atom to the hydridic H atom
leading to a strong (C8H14)B–H interaction in the second-
ary coordination sphere. The measured B1–H1 distance of
1.38(3) Å is much shorter than those in trans-4b [1.60(6) Å]
and the analogous rhenium phosphanylborane complex
HRe(CO)4[κB,P-Ph2PCH2CH2B(C8H14)] [1.46 Å],[8] which
indicates that the interaction between these two atomic cen-
ters is much stronger. Three strained chelate rings (one four-
membered and two six-membered rings) are formed around
the W center resulting from three fold coordination of the
phosphanylborane ligand. The P1–W1–P2 bite angle for the
four-membered chelate was found to be 65.07(2)°, which is clarity.
Figure 5. Thermal ellipsoid plot of the molecular structure of cis-
6b. All hydrogen atoms except the hydride ligand are omitted for
Eur. J. Inorg. Chem. 0000, 0–0
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The obtained crystal structure closely resembles that of
cis-5b with minor differences in bond lengths and angles.
Owing to the coordination of the B(C8H14) group, P1 and
P2 are bent down, as was observed from the N1–W1–P1
and N1–W1–P2 bond angles of 101.4(3) and 102.0(3)°,
respectively. Two five-membered and one six-membered
chelate rings are formed around the W center involving
atoms of the phosphanylborane ligand. However, high stan-
dard deviations were found for the W1–H1 and B1–H1
bond lengths (2.08 and 1.00 Å), which made the compari-
son difficult.
DFT Calculations
Figure 6. DFT-optimized structures at the B3LYP level with calcu-
lated NBO charges (in parentheses) and relative energies of cis-5c
with a 3c–2e W–H–B bond and cis-5d with a dissociated H–B
bond. Hydrogen atoms are omitted except for the W–H bond for
clarity purpose.
In addition, we compared the energy difference between
the model complex cis-[W(CO)2(2)(NO) (H)] (cis-5c) with
3c–2e W–H–B bonding and cis-[W(CO)2(2)(NO)(H)] (cis-
5d) without H–B interactions. DFT calculations were per-
formed at the B3LYP level with a SDD basis set for W and
the standard 6-31g(d) basis set for the other atoms to evalu-
ate the strength of the H–B bond in the 3c–2e W–H–B in-
teraction of cis-5b. The geometry optimization procedure
revealed species as local and global minima. The optimized
structure of cis-5c exhibits an excellent agreement with the
solid-state structure of cis-5b (Table 1), which provides fur-
ther evidence of the favorable existence of the 3c–2e W–H–
B interaction in cis-5b. The deviation of the boron moiety
from the W–H bond leads to disruption of the 3c–2e W–
H–B interaction in the optimized isomer cis-5d. The geome-
tries and relative energies of cis-5c and cis-5d are shown in
Figure 6. The W–H bond length in cis-5d (1.836 Å) is
slighted shorter than that in cis-5c (1.915 Å), which reflects
the enhanced hydridicity of the W–H moiety. This is rea-
sonable owing to the loss of interaction with the Lewis
acidic borane moiety. A relative potential energy difference
of +0.8 kcal/mol (ΔE) between cis-5c and cis-5d was deter-
mined in favor of cis-5c. Such close thermodynamics sug-
gests that the H–B bond in cis-5b is relatively weak, which
is consistent with the secondary coordination sphere mode.
The 3c–2e W–H–B bond orbital could be identified and
mainly bears the σ-bond character of the W–H–B unit, but
O atom of the NO group. Finally, it should also be noted
that no interaction between the pendant B atom with the O
atom of either the NO or the CO group in cis-5d could be
located by DFT. The preferential affinity of the B atom
toward the hydride ligand over the ancillary CO group
might account for the inertness of the complexes toward
activation of the CO ligand or subsequent insertion into the
W–H bond.
Moreover, a DFT optimization of compound cis-6b at
the B3LYP level has been performed based on the simpli-
fied model complex cis-[W(CO)2(4)(NO)(H)] {4
=
Me2PCH2CH[B(C8H14)]PMe2}. The geometry parameters
are given in Table 1. Significantly, a W–H bond length of
1.953 Å and a B–H bond length of 1.375 Å were found,
which are in agreement with the distances determined in the
solid-state structure of cis-5b, wherein the hydride location
could be refined.
Conclusions
This work describes an approach to tungsten nitrosyl
also some admixture of other types of orbital character ow- complexes bearing multidentate phosphanylborane ligands,
ing to symmetry lowering by bending. The main bonding and metal–ligand interactions both in the primary and sec-
contribution is located between the hydride ligand and the ondary coordination spheres are discussed. The intercon-
boron atom. Moreover, the C–H···O distances of more than version of cis-4a and trans-4a was pursued, and both iso-
2.690 Å between the B(C8H14) group and the OCO or ONO mers were fully characterized. Single-crystal X-ray structure
atoms may indicate very weak electrostatic interactions, analyses revealed the identities of the cis and trans com-
which are too small to significantly influence the energies plexes and the coordination behaviors of 1–3, in particular,
of cis-5a and cis-5b.
the uncommon 1,1-chelating behavior of the PB ligand 2
A natural bond orbital (NBO) analysis revealed that the in the primary coordination sphere and the coordination
natural charge on boron increased from 0.50 in cis-5c to environment of the pendant B(C8H14) group(s) in the sec-
1.00 in cis-5d, which is reasonable because of the loss of ondary sphere. In addition, three tungsten nitrosyl hydride
electron donation from the W–H bond to the B–H bond. complexes were prepared and studied not only by spectro-
The natural charge on both the W and H atoms becomes scopic methods but also by single-crystal X-ray analyses.
more negative, as the change from cis-5c to cis-5d enables The phosphane and borane moieties of the ambiphilic
stronger π-back donation to the trans nitrosyl ligand as evi- phosphanylborane ligand in the hydride complexes coordi-
denced by the increased negative density on both the N and nate to the W center and the hydride ligand to form biden-
Eur. J. Inorg. Chem. 0000, 0–0
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bis(diphenylphosphanyl)ethylene were purchased from commercial
sources and used without further purification. NMR spectra were
measured with a Varian Gemini-300 instrument (96.28 MHz for
11B) and with a Bruker DRX 400 spectrometer (400.1 MHz for
1H, 162.0 MHz for 31P{1H}). Chemical shifts are expressed in ppm
relative to tetramethylsilane (TMS, 1H), 85% H3PO4 (31P{1H}),
and BF3OEt2 (11B, external standard). Signal patterns are as fol-
lows: s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet. IR
spectra were obtained either by attenuated total reflectance (ATR)
or KBr methods with a Bio-rad FTS-45 instrument. Elemental
tate (in trans-4b) or tridentate chelate rings (in cis-5b and
cis-6b). The interaction of the borane moiety with the hyd-
ridic H atom resulted in a 3c–2e W–H–B bond, which was
observed in their crystal structures. The preference of bor-
ane coordination to the H atom of the W–H bond over CO
or NO was invariably seen in all the hydride crystal struc-
tures. These results have contributed to the understanding
of σ coordination of a metal hydride bond to the Lewis
acidic boron center present in the secondary coordination
sphere. The nature of the 3c–2e W–H–B moiety in cis-5b analyses were performed at the Anorganisch-Chemisches Institut
of the University of Zürich.
was also evaluated by DFT structural optimization, and a
weak W–H–B interaction is present in cis-5c. Further in-
vestigations on possible catalytic applications of tungsten
nitrosyl hydride complexes consisting of electron rich phos-
phanylborane ligands are underway in our laboratory.
Crystal Structure Determination: The data collection and structure-
refinement data for compounds cis-4a, trans-4a, cis-5a, trans-4b,
cis-5b, and cis-6b are presented in Tables 2 and 3. Single-crystal X-
ray diffraction data were collected at 183(2) K with an Xcalibur
diffractometer (Agilent Technologies, Ruby CCD detector) for all
compounds by using a single wavelength Enhance X-ray source
with Mo-Kα radiation (λ = 0.71073 Å).[27] The selected single crys-
tals were mounted in polybutene oil on top of a glass fiber fixed
on a goniometer head and immediately transferred to the dif-
fractometer. Pre-experiment, data collection, data reduction, and
analytical absorption corrections[28] were performed with the Crys-
Alis Pro program suite.[27] The crystal structures were solved with
SHELXS97[29] by using direct methods. The structure refinements
were performed by full-matrix least-squares on F2 with
SHELXL97.[29] All programs used during the crystal structure de-
termination process are included in the WINGX software.[30]
PLATON[31] was used to check the result of the X-ray analyses.
Experimental Section
General Considerations: All experiments were performed under an
atmosphere of nitrogen and by using either dry glove box or
Schlenk techniques. Reagent grade tetrahydrofuran, pentane, and
toluene were dried with sodium benzophenone and distilled prior
to use under a N2 atmosphere. Deuterated solvents were dried with
sodium benzophenone ketyl ([D8]THF, [D8]toluene) and distilled
by a freeze–pump–thaw cycle prior to use. The tungsten precursor
complex [W(NO)(CO)4(ClAlCl3)] was prepared by following a sim-
ilar procedure to that for Mo(NO)(CO)4(ClAlCl3),[26] and
Ph2PCH2CH2B(C8H14) was prepared by following a literature pro- For more details about the refinements, see the refine_special_de-
cedure.[25] A 1 m toluene solution of NaHBEt3, a 0.5 m THF solu-
tion of 9-BBN, 1,1-bis(diphenylphosphanyl)ethylene, and 1,2-
tails and iucr_refine_instructions_details sections in the crystallo-
graphic information files.
Table 2. Crystallographic data for cis-4a, trans-4a, and trans-4b.
cis-4a
trans-4a
trans-4b
Empirical formula
Formula weight /gmol–1
Temperature /K
Wavelength /Å
Crystal system, space group
a /Å
b /Å
c /Å
α /°
β /°
C46H56B2ClNO3P2W. C 4H8O
1045.88
183(2)
C46H56B2ClNO3P2W
973.78
183(2)
C46H57B2NO3P2W
939.34
183(2)
0.71073
0.71073
triclinic, P1
0.71073
¯
monoclinic, C2/c
16.2488(2)
15.5033(2)
19.9305(3)
90
90.382(1)
90
5020.58(12)
4, 1.384
2.460
monoclinic, P21/c
20.2110(9)
11.2801(3)
18.8680(8)
90
91.410(4)
90
4300.3(3)
4, 1.451
2.801
10.9364(6)
11.1237(5)
11.1619(5)
115.873(5)
111.492(5)
94.269(4)
1091.39(9)
1, 1.482
2.821
γ /°
Volume /Å3
Z, density (calcd) /Mgm–3
Absorption coefficient /mm–1
F(000)
2136
494
1912
Crystal size /mm
θ range /°
0.50ϫ0.36ϫ0.26
2.63 to 30.51
44937
7650/Rint = 0.0241
99.9
analytical
0.543 and 0.379
7408/15/284
1.182
0.12ϫ0.10ϫ0.03
2.52 to 25.68
11362
4141/Rint = 0.0519
99.9
analytical
0.915 and 0.773
4141/340/302
1.027
0.30ϫ0.16ϫ0.03
2.82 to 28.28
46208
10658/Rint = 0.0688
99.9
analytical
0.928 and 0.502
7517/111/524
1.041
Reflections collected
Unique reflections
Completeness to θ /%
Absorption correction
Max/min transmission
Data/restraints/parameters
Goodness-of-fit on F2
Final R1 and wR2 indices
[IϾ2σ(I)][a]
0.0261, 0.0756
0.0453, 0.0748
0.0595, 0.1390
R1 and wR2 indices (all data)
0.0272, 0.0761
1.001 and –1.059
0.0520, 0.0778
0.763 and –0.745
0.0918, 0.1589
3.469 and –0.984
Largest diff. peak and hole /eÅ–3
[a] The unweighted R factor is R1 = Σ(Fo – Fc)/ΣFo; IϾ2σ(I), and the weighted R factor is wR2 = {Σw(Fo – Fc ) /Σw(Fo2)2}1/2
.
2
2 2
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Table 3. Crystallographic data for cis-5a, cis-5b and cis-6b.
cis-5a
trans-5a
trans-6b
Empirical formula
Formula weight /gmol–1
Temperature /K
Wavelength /Å
Crystal system, space group
a /Å
b /Å
c /Å
α /°
C36H37BClNO3P2W
823.72
183(2)
0.71073
orthorhombic, Pbca
12.5277(4)
16.5704(4)
33.1759(10)
90
2(C36H38BNO3P2W), C5H12
1650.69
183(2)
C36H38BNO3P2W
789.27
183(2)
0.71073
0.71073
¯
triclinic, P1
11.1060(3)
11.3634(3)
16.0042(6)
71.287(3)
monoclinic, P21/c
9.8618(6)
39.730(2)
8.6887(6)
90
β /°
90
90
6887.0(3)
8, 1.589
3.561
74.746(3)
79.978(2)
1836.70(10)
1, 1.492
3.268
106.228(7)
90
3268.7(3)
4, 1.604
3.669
1576
γ /°
Volume /Å3
Z, density (calcd) /Mgm–3
Absorption coefficient /mm–1
F(000)
3280
830
Crystal size /mm
θ range /°
0.47ϫ0.35ϫ0.14
2.75 to 30.51
33235
10486/Rint = 0.0483
99.9
analytical
0.647 and 0.306
8046/238/480
1.079
0.50ϫ0.39ϫ0.26
2.82 to 30.51
33118
11197/Rint = 0.0394
99.9
analytical
0.516 and 0.279
10384/31/446
1.073
0.27ϫ0.22ϫ0.06
2.89 to 26.37
35531
Reflections collected
Unique reflections
Completeness to θ /%
Absorption correction
Max/min transmission
Data/restraints/parameters
Goodness-of-fit on F2
14242/Rint = 0.0000[b]
99.8
analytical
0.799 and 0.494
12412/30/397
1.201
[a]
Final R1 and wR2 indices
0.0453, 0.0918
0.0248, 0.0581
0.0819, 0.2090
[IϾ2σ(I)]
R1 and wR2 indices (all data)
0.0658, 0.1007
2.317 and –1.080
0.0283, 0.0602
1.160 and –1.010
0.0941, 0.2147
4.120 and –3.769
Largest diff. peak and hole /eÅ–3
2
2 2
[a] The unweighted R factor is R1 = Σ(Fo – Fc)/ΣFo; IϾ2σ(I), and the weighted R factor is wR2 = {Σw(Fo – Fc ) /Σw(Fo2)2}1/2. [b] The
HKLF5 file used in the final refinement contains unmerged data.
CCDC-916629 (for cis-4a), -916630 (for trans-4a), -916631 (for
trans-4b), -916632 (for cis-5a), -916633 (for cis-5b), and -916634
(for cis-6b) contain the supplementary crystallographic data for this
paper. These data can be obtained free of charge from The Cam-
bridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
1.89–2.30 [m, 14 H, B(C8H14)] ppm. C38H45BP2O (3·THF, 590.29):
calcd. C 77.25, H 7.68; found C 77.10, H 7.54.
cis-[W(CO)2{Ph2PCH2CH2B(C8H14)}2(NO)(Cl)] (cis-4a): Com-
pound 1 (135.6 mg, 0.4 mmol) was added to a stirred THF solution
of [W(CO)4(NO)(ClAlCl3)] (100 mg, 0.2 mmol). The mixture was
heated at 70 °C for 5 min, and the reaction progress was monitored
by 31P{1H} NMR spectroscopy. After the reaction was complete,
the solution was dried under reduced pressure. The solid obtained
was washed with pentane several times. The solid was further ex-
tracted with toluene and dried under vacuum to afford the desired
product. Recrystallization was performed by slow diffusion of pent-
ane into a saturated toluene solution at –25 °C, yield 0.185 g
Ph2PCH(PPh2)CH2B(C8H14) (2): A mixture of 1,1-bis(diphenyl-
phosphanyl)ethylene (1 g, 2.52 mmol) and 9-BBN (0.5 m in THF,
5.05 mL, 2.52 mmol) was charged in a pressure vessel and then
heated at 120 °C for 3 d. The solvent was removed under reduced
pressure, and the obtained white oil was extracted with pentane.
The pentane extract was concentrated and kept at –25 °C to afford
colorless crystals of the desired ligand 2, yield 1.14 g (2.19 mmol,
87%). 31P{1H} NMR ([D8]THF, 162 MHz): δ = 2.69 (s, PPh2) ppm.
(0.19 mmol, 95%). FTIR (Solid, ATR): ν = 2016 (vs, νCO), 1937
˜
(vs, νCO), 1619 (vs, νNO
)
cm–1. 31P{1H} NMR ([D8]THF,
11B NMR ([D8]THF, 96.28 MHz): δ = 59.1 [br, B(C8H14)] ppm. 1H 162 MHz): δ = 8.90 [s, 1JP,W (satellites) = 252.7 Hz] ppm. 11B NMR
NMR ([D8]THF, 400 MHz): δ = 7.27–7.46 (m, 20 H, PhH), 3.91 ([D8]THF, 96.28 MHz): δ = 42.7 [br, B(C8H14)] ppm. 1H NMR
(m, 1 H, CH), 1.73–1.93 (m, 2 H, CH2), 1.43–1.72 [m, 14 H, ([D8]THF, 400 MHz): δ = 7.19–7.43 (m, 20 H, PhH), 2.50 (t, 4 H,
B(C8H14)] ppm. C34H37BP2 (518.24): calcd. C 78.73, H 7.20; found
C 78.51, H 7.14.
br, CH2), 2.26 (t, 4 H, br, CH2), 1.53–1.62 [m, 28 H, B(C8H14)]
ppm. C50H64B2ClNO4P2W (4a·C4H8O, 1045.73): calcd. C 57.38, H
6.17, N 1.34; found C 57.26, H 6.13, N 1.32.
Ph2PCH2CH[B(C8H14)]PPh2 (3): Ligand 3 was prepared from a
reaction of 1,2-bis(diphenylphosphanyl)ethylene (1 g, 2.52 mmol)
and 9-BBN (0.5 m in THF, 5.05 mL, 2.52 mmol) under similar reac-
tion conditions as those for 2. Colorless crystals of 3 were obtained
trans-[W(CO)2{Ph2PCH2CH2B(C8H14)}2(NO)(Cl)] (trans-4a):
A
toluene solution of cis-4a was heated at 70 °C, and the reaction
was monitored by 31P NMR spectroscopy. The reaction was found
to be complete within six hours. The solvent was removed in vacuo
from
a saturated pentane solution at –25 °C, yield 1.21 g
(2.34 mmol, 93%). 31P{1H} NMR ([D8]THF, 162 MHz): δ = –10.63
(d, 3JP,P = 32.4 Hz, 1 P, PPh2), –9.97 (d, 3JP,P = 32.4 Hz, 1 P, PPh2)
to afford pure trans-4a, yield 100%. FTIR (KBr, Solid): ν = 1945
˜
(vs, νCO), 1605 (vs, νNO
)
cm–1. 31P{1H} NMR ([D8]THF,
ppm. 11B NMR ([D8]THF, 96.28 MHz): δ = 85.6 [br, B(C8H14)] 162 MHz): δ = 16.72 [s, JP,W (satellites) = 281.9 Hz] ppm. 11B
ppm. 1H NMR ([D8]THF, 400 MHz): δ = 7.21–7.34 (m, 20 H, NMR ([D8]THF, 96.28 MHz): δ = 36.4 [br, B(C8H14)] ppm. 1H
PhH), 2.77 (m, 1 H, CH), 2.48 (m, 1 H, CH2), 2.34 (m, 1 H, CH2), NMR ([D8]THF, 400 MHz): δ = 7.28–7.63 (m, 20 H, PhH), 2.64
1
Eur. J. Inorg. Chem. 0000, 0–0
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© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

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/KAP1
Date: 04-05-13 12:20:19
Pages: 13
www.eurjic.org
FULL PAPER
(m,
4
H, CH2), 1.55 [m, 28 H, B(C8H14)] ppm. B(C8H14)] ppm. 1H NMR ([D8]toluene, 400 MHz): δ = 6.93–7.79
C46H56B2ClNO3P2W·AlCl3·2(C4H8O) (1251.13): calcd. C 51.79, H
5.80, N 1.12; found C 52.70, H 5.46, N 1.12.
(m, 20 H, PhH), 2.90 (m, 2 H, CH2), 2.81 (m, 4 H, CH2), 2.64 (m,
2 H, CH2), 1.63–1.80 [m, 28 H, B(C8H14)], –6.27 (t, 1 H, br, W–H)
ppm. C46H57B2NO3P2W (939.23): calcd. C 58.77, H 6.12, N 1.49;
found C 58.67, H 6.08, N 1.46.
cis-[W(CO)2{Ph2PCH(PPh2)CH2B(C8H14)}(NO)(Cl)]
(cis-5a):
Complex cis-5a was prepared from the reaction of 2 (104 mg,
0.2 mmol) and [W(CO)4(NO)(ClAlCl3)] (100 mg, 0.2 mmol) in
THF at 70 °C. The reaction was monitored by 31P{1H} NMR spec-
troscopy. After five minutes, the reaction was complete, and a
major (90%) and a minor product (10%) formed as evidenced from
NMR spectra. The reaction mixture was then dried under reduced
pressure, and the obtained solid was washed several times with
pentane. The solid was then recrystallized from a pentane/THF
solution at –25 °C to afford analytically pure cis-5a, yield 140 mg
cis-[W(CO)2{Ph2PCH(PPh2)CH2B(C8H14)}(NO)(H)] (cis-5b):
A
[D8]toluene solution of cis-5a (150 mg, 0.18 mmol) was titrated
with NaHBEt3 (1 m solution in toluene) at –25 °C with vigorous
shaking until a hydride signal was observed by 1H NMR spec-
troscopy. On completion, the reaction mixture was filtered through
a small Celite bed, and the resulting red solution was dried in vacuo
to afford a deep brown solid. The solid was washed several times
with pentane and recrystallized from a toluene/pentane mixture at
–25 °C to afford a brown product, yield 84 mg (0.11 mmol, 58%).
(0.17 mmol, 85%). FTIR [Solid, ATR]: ν = 2014 (vs, νCO), 1934 (vs,
˜
νCO), 1620 (vs, νNO) cm–1. 31P{1H} NMR ([D8]THF, 162 MHz): δ
FTIR (Solid, ATR): ν = 2015 (vs, νCO), 1937 (vs, νCO), 1627 (vs,
˜
1
= 2.10 [s, JP,W (satellites) = 212.2 Hz] ppm. 11B NMR ([D8]THF,
νNO) cm–1. 31P{1H} NMR ([D8]toluene, 162 MHz): δ = 4.44 [s,
96.28 MHz): δ = 86.8 [br, B(C8H14)] ppm. 1H NMR ([D8]THF,
400 MHz): δ = 7.30–7.79 (m, 20 H, PhH), 2.12 (m, 1 H, CH), 1.92
1JP,W (satellites)
=
213.8 Hz] ppm. 11B NMR ([D8]toluene,
1
96.28 MHz): δ = 39.6 [br, B(C8H14)] ppm. H NMR ([D8]toluene,
400): δ = 7.03–7.75 (m, 20 H, PhH), 2.37 (m, 1 H, CH), 1.98 (m,
2 H, CH2), 1.32–1.70 [m, 14 H, B(C8H14)], –6.20 (s, 1 H, br, W–H)
ppm. C36H38BNO3P2W (789.08): calcd. C 54.75, H 4.85, N 1.77;
found C 54.53, H 4.87, N 1.72.
(m,
2 H, CH2), 1.44–1.71 [m, 14 H, B(C8H14)] ppm.
C36H37BClNO3P2W (823.53): calcd. C 52.46, H 4.53, N 1.70; found
C 52.68, H 4.46, N 1.67.
cis-[W(CO)2{Ph2PCH2CH{B(C8H14)}PPh2}(NO)(Cl)]
(cis-6a):
Compound 3 (100 mg, 0.192 mmol) was treated with [W(CO)4-
(NO)(Cl)(AlCl3)] (95.06 mg, 0.192 mmol) in THF at 70 °C. The re-
action was finished in 5 min as indicated by 31P{1H} NMR spec-
troscopy. Two sets of doublet signals in the 31P{1H} NMR spec-
trum suggested that two diastereomers were formed in a ratio of
30:70. The solvent was removed under reduced pressure, and the
obtained solid was extracted with toluene several times. The tolu-
ene solution was dried in vacuo to afford a yellow solid of the
isomeric mixture of the desired complex cis-6a, yield 0.148 g
cis-[W(CO)2{Ph2PCH2CH{B(C8H14)}PPh2}(NO)(H)] (cis-6b):
A
[D8]toluene solution of cis-6a (100 mg, 0.12 mmol) was cooled to
–25 °C. A 1 m solution of NaHBEt3 (0.243 mL, 0.2 mmol) in tolu-
ene solution was added dropwise to the cooled solution of the com-
plex. A precipitate formed, and the reaction was immediately fin-
1
ished as indicated by 31P{1H} NMR monitoring. H and 31P{1H}
NMR spectroscopy indicated the formation of the desired hydride
complex. The solution was filtered through a small Celite bed in-
side a glove box, and the filtrate was dried under reduced pressure
to afford an orange oil. The oil was extracted several times with
pentane, and the pentane solution was dried in vacuo to afford a
mixture of yellow and white substances. The solid was kept in
vacuo for about 6 h to remove all of the volatile white compound.
Recrystallization from saturated pentane solution afforded yellow
crystals of the desired hydride complex, yield 71 mg (0.09 mmol,
(0.18 mmol, 94%). FTIR (Solid, ATR): ν = 2015 (vs, νCO), 1938
˜
(vs, νCO), 1620 (vs, νNO
162 MHz): major isomer (70%): δ = 35.07 [d, JP,P = 6.5 Hz, JP,W
)
cm–1. 31P{1H} NMR ([D8]THF,
3
1
3
1
(satellites) = 251.1 Hz, 1 P, PPh2], 48.09 [d, JP,P = 8.1 Hz, JP,W
(satellites) = 244.6 Hz, 1 P, PPh2]; minor isomer (30%): δ =36.24
[d, 3JP,P = 3.2 Hz, 1JP,W (satellites) = 252.7 Hz, 1 P, PPh2], 53.21 [d,
1
3JP,P = 1.6 Hz, JP,W (satellites) = 246.2 Hz, 1 P, PPh2] ppm. 11B
72%). FTIR (KBr, Solid): ν = 2026 (vs, νCO), 1948 (vs, νCO), 1607
˜
NMR ([D8]THF, 96.28 MHz): δ = 84.9 [br, B(C8H14)] ppm. 1H
NMR ([D8]THF, 400 MHz): major isomer (70%): δ = 7.31–7.39
(m, 20 H, PhH), 3.02–3.40 (m, 3 H, CH2 and CH), 1.65–1.68 [m,
14 H, B(C8H14)]; minor isomer (30%): δ = 7.46–7.75 (m, 20 H,
PhH), 2.67 (m, 2 H, CH2), 2.47 (m, 1 H, CH), 1.28–1.45 [m, 14 H,
B(C8H14)] ppm. C40H45AlBCl4NO4P2W (6a·AlCl3·THF, 1029.18):
calcd. C 46.68, H 4.41, N 1.36; found C 46.53, H 4.50, N 1.10.
(vs, νNO), 1637 (vs, νWH) cm–1. 31P{1H} NMR ([D8]toluene,
162 MHz): δ = 35.81 [d, 3JP,P = 6.5 Hz, 1JP,W (satellites) = 246.2 Hz,
3
1
1 P], 17.54 [d, JP,P = 6.5 Hz, JP,W (satellites) = 258.4 Hz, 1 P]
ppm. 11B NMR ([D8]toluene, 96.28 MHz): δ = 90.34 [B(C8H14)]
ppm. 1H NMR ([D8]toluene, 400 MHz): δ = 6.62–7.78 (m, 20 H,
PhH), 2.90 (m, 1 H, CH2), 2.71 (m, 1 H, CH2), 2.61 (m, 1 H, CH),
1.60–1.78 [m, 14 H, B(C8H14)], –6.68 (t,
1 H, br) ppm.
C36H38BNO3P2W (789.08): calcd. C 54.75, H 4.85, N 1.77; found
C 54.58, H 4.78, N 1.73.
Synthesis of the Tungsten Hydride Complexes trans-4b, cis-5b and
cis-6b
Computational Methods: All calculations were performed with the
Gaussian 03 program package[32] by using the popular B3LYP
functional[33] in conjunction with the Stuttgart, Germany/Dresden
effective core potentials (SDD) basis set[34] for the W center and
the standard 6-31g(d)[35] basis set for the remaining atoms. Sums
of electronic and zero-point energies were taken as relative energies.
trans-[W(CO)2{Ph2PCH2CH2B(C8H14)}2(NO)(H)] (trans-4b):
[D8]toluene solution of trans-4a (150 mg, 0.15 mmol) was titrated
with NaHBEt3 (1 m solution in toluene, ca. 2.2 equiv. was required)
A
1
at 70 °C over a few hours, and the reaction was monitored by H
and 31P{1H} NMR spectroscopy. A precipitate was formed during
the reaction. The reaction mixture was then cooled to room tem-
perature, and filtered through a small Celite bed in a glove box.
The filtrate was dried in vacuo to remove the solvent and volatile
BEt3 produced in the reaction. The obtained dark brown substance
was washed several times with cold pentane. The obtained solid
was recrystallized from a toluene/pentane solution to afford single
crystals of trans-4b, yield 89 mg (0.10 mmol, 62%). FTIR (ATR,
Supporting Information (see footnote on the first page of this arti-
cle): Relevant details about the structure refinements and DFT cal-
culations.
Acknowledgments
Solid): ν = 1946 (vs, νCO), 1625 (vs, νNO) cm–1. 31P{1H} NMR
˜
1
([D8]toluene, 162 MHz): δ = 24.43 [br. s, JP,W (satellites) =
Financial support from the Swiss National Science Foundation,
Lanxess AG, Leverkusen, Germany, the Funds of the University
283.5 Hz] ppm. 11B NMR ([D8]toluene, 96.28 MHz): δ = 41.5 [br,
Eur. J. Inorg. Chem. 0000, 0–0
11
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Job/Unit: I21565
/KAP1
Date: 04-05-13 12:20:19
Pages: 13
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FULL PAPER
2004, 23, 5656–5658; e) D. J. Mihalcik, J. L. White, J. M. Tan-
ski, L. N. Zakharov, G. P. A. Yap, C. D. Incarvito, A. L. Rhein-
gold, D. Rabinovitch, Dalton Trans. 2004, 1626–1634; f) R. J.
Blagg, J. P. H. Charmant, N. G. Connelly, M. F. Haddow, A. G.
Orpen, Chem. Commun. 2006, 2350–2352; g) I. R. Crossley,
A. F. Hill, A. C. Willis, Organometallics 2005, 24, 1062–1064;
h) I. R. Crossley, M. R. St.-J. Foreman, A. F. Hill, A. J. P.
White, D. J. Williams, Chem. Commun. 2005, 221–223; i) I. R.
Crossley, A. F. Hill, E. R. Humphrey, A. C. Willis, Organome-
tallics 2005, 24, 4083–4086; j) J. S. Figueroa, J. G. Melnick, G.
Parkin, Inorg. Chem. 2006, 45, 7056–7058; k) K. Pang, S. M.
Quan, G. Parkin, Chem. Commun. 2006, 5015–5017; l) I. R.
Crossley, A. F. Hill, A. C. Willis, Organometallics 2007, 26,
3891–3895; m) I. R. Crossley, A. F. Hill, Dalton Trans. 2008,
201–203; n) S. Senda, Y. Ohki, T. Hirayama, D. Toda, J.-L.
Chen, T. Matsumoto, H. Kawaguchi, K. Tatsumi, Inorg. Chem.
2006, 45, 9914–9925.
a) G. C. Welch, S. Juan, R. R. Masuda, D. W. Stephan, Science
2006, 314, 1124–1126; b) S. J. Geier, T. M. Gilbert, D. W. Ste-
phan, J. Am. Chem. Soc. 2008, 130, 12632–12633; c) C. M.
Mömming, S. Frömel, G. Kehr, R. Fröhlich, S. Grimme, G.
Erker, J. Am. Chem. Soc. 2009, 131, 12280–12289; d) D. W.
Stephan, G. Erker, Angew. Chem. 2010, 122, 50; Angew. Chem.
Int. Ed. 2010, 49, 46–76; e) P. Spies, G. Erker, G. Kehr, K.
Bergander, R. Fröhlich, S. Grimme, D. W. Stephan, Chem.
Commun. 2007, 5072–5074.
a) C. M. Mömming, E. Otten, G. Kehr, R. Fröhlich, S.
Grimme, D. W. Stephan, G. Erker, Angew. Chem. 2009, 121,
6770; Angew. Chem. Int. Ed. 2009, 48, 6643–6646; b) S. Moebs-
Sanchez, N. Saffon, G. Bouhadir, L. Maron, D. Bourissou,
Dalton Trans. 2010, 39, 4417–4420; c) S. Frömel, R. Fröhlich,
C. G. Daniliuc, G. Kehr, G. Erker, Eur. J. Inorg. Chem. 2012,
3774–3779.
a) T. Agou, J. Kobayashi, T. Kawashima, Org. Lett. 2005, 7,
4373–4376; b) T. Agou, J. Kobayashi, T. Kawashima, Inorg.
Chem. 2006, 45, 9137–9144.
M. W. P. Bebbington, S. Bontemps, G. Bouhadir, D. Bourissou,
Angew. Chem. 2007, 119, 3397; Angew. Chem. Int. Ed. 2007,
46, 3333–3336.
a) M. W. P. Bebbington, G. Bouhadir, D. Bourissou, Eur. J.
Org. Chem. 2007, 27, 4483–4486; b) J. Rathke, R. Schaeffer,
Inorg. Chem. 1972, 11, 1150–1151; c) J. C. Thomas, J. C. Peters,
Polyhedron 2004, 23, 2901–2913; d) H. Schmidbaur, M. Sigl,
A. Schier, J. Organomet. Chem. 1997, 529, 323–327.
For molybdenum, see: a) S. Namorado, M. A. Antunes, L. F.
Veiros, J. R. Ascenso, M. T. Duarte, A. M. Martins, Organome-
tallics 2008, 27, 4589–4599; b) B. F. M. Kimmich, P. J. Fagan,
E. Hauptman, W. J. Marshall, R. M. Bullock, Organometallics
2005, 24, 6220–6229.
For tungsten, see: a) R. M. Bullock, J.-S. Song, J. Am. Chem.
Soc. 1994, 116, 8602–8612; b) R. M. Bullock, M. H. Voges, J.
Am. Chem. Soc. 2000, 122, 12594–12595; c) Y. Zhao, H. W.
Schmalle, T. Fox, O. Blacque, H. Berke, Dalton Trans. 2006,
73–85; d) F. Wu, V. K. Dioumaev, D. J. Szalda, J. Hanson,
R. M. Bullock, Organometallics 2007, 26, 5079–5090.
For molybdenum and tungsten, see: a) M. H. Voges, R. M.
Bullock, J. Chem. Soc., Dalton Trans. 2002, 759–770; b) R. M.
Bullock, Chem. Eur. J. 2004, 10, 2366–2374; c) A. Dybov, O.
Blacque, H. Berke, Eur. J. Inorg. Chem. 2010, 21, 3328–3337.
a) Z. Chen, H. W. Schmalle, T. Fox, H. Berke, Dalton Trans.
2005, 580–587; b) J. Höck, H. Jacobsen, H. W. Schmalle,
G. R. J. Artus, T. Fox, J. I. Amor, F. Bäth, H. Berke, Organome-
tallics 2001, 20, 1533–1544; c) F. Liang, H. Jacobsen, H. W.
Schmalle, T. Fox, H. Berke, Organometallics 2000, 19, 1950–
1962; d) F. Liang, H. W. Schmalle, T. Fox, H. Berke, Organome-
tallics 2003, 22, 3382–3393; e) F. Liang, H. W. Schmalle, H.
Berke, Inorg. Chem. 2004, 43, 993–999; f) J. Cugny, H. W.
Schmalle, T. Fox, O. Blacque, M. Alfonso, H. Berke, Eur. J.
Inorg. Chem. 2006, 3, 540–552.
of Zurich, the Deutsche Forschungsgemeinschaft (DFG), and the
Swiss National Science Foundation (SNF) within the project “For-
schergruppe 1175 - Unconventional Approaches to the Activation
of Dihydrogen” are gratefully acknowledged.
[1] a) A. J. M. Miller, J. A. Labinger, J. E. Bercaw, J. Am. Chem.
Soc. 2008, 130, 11874–11875; A. J. M. Miller, J. A. Labinger,
J. E. Bercaw, J. Am. Chem. Soc. 2010, 132, 3301–3303; b)
A. J. M. Miller, J. A. Labinger, J. E. Bercaw, Organometallics
2010, 29, 4499–4516; c) N. M. West, A. J. M. Miller, J. A. Lab-
inger, J. E. Bercaw, Coord. Chem. Rev. 2011, 255, 881–898; d)
J. E. Bercaw, J. A. Labinger, Proc. Natl. Acad. Sci. USA 2007,
104, 6899–6900.
[2] J. Boudreau, F.-G. Fontaine, Organometallics 2011, 30, 511–
519.
[3] A. Fischbach, P. R. Bazinet, R. Waterman, T. D. Tilley, Orga-
nometallics 2008, 27, 1135–1139.
[4] R. H. Crabtree, Angew. Chem. 1993, 105, 828; Angew. Chem.
Int. Ed. Engl. 1993, 32, 789–805.
[5] K. K. Pandey, Coord. Chem. Rev. 2009, 253, 37–55.
[6] A. Amgoune, S. Ladeira, K. Miqueu, D. Bourssou, J. Am.
Chem. Soc. 2012, 134, 6560–6563.
[7] A. Zech, M. F. Haddow, H. Othman, G. R. Owen, Organome-
tallics 2012, 31, 6753–6760.
[8] S.-H. Huang, X. Wang, M. G. Richmond, J. Organomet. Chem.
2012, 700, 103–109.
[9] F. G. Fontaine, J. Boudreau, M.-H. Thibault, Eur. J. Inorg.
Chem. 2008, 35, 5439–5454.
[10] I. Kuzu, I. Krummenacher, J. Meyer, F. Armbruster, F. Breher,
Dalton Trans. 2008, 5836–5865.
[11] a) H. Braunschweig, R. D. Dewhurst, A. Schneider, Chem. Rev.
2010, 110, 3924–3957; b) H. Braunschweig, K. Gruss, K. Rad-
acki, Angew. Chem. 2009, 121, 4303; Angew. Chem. Int. Ed.
2009, 48, 4239–4241; c) H. Braunschweig, C. Kollann, D. Rais,
Angew. Chem. 2006, 118, 5380; Angew. Chem. Int. Ed. 2006, 45,
5254–5274; d) D. J. H. Emslie, L. E. Harrington, H. A. Jenkins,
C. M. Robertson, J. F. Britten, Organometallics 2008, 27, 5317–
5325; e) S. Bontemps, G. Bouhadir, K. Miqueu, D. Bourissou,
J. Am. Chem. Soc. 2006, 128, 12056–12057; f) D. J. H. Emslie,
J. M. Blackwell, J. F. Britten, L. E. Harrington, Organometal-
lics 2006, 25, 2412–2414; g) S. R. Oakley, K. D. Parker, D. J. H.
Emslie, I. Vargas-Baca, C. M. Robertson, J. E. Harrington, J. F.
Britten, Organometallics 2006, 25, 5835–5838; h) M. Sircoglou,
S. Bontemps, G. Bouhadir, N. Saffon, K. Miqueu, W. Gu, M.
Mercy, C.-H. Chen, B. M. Foxman, L. Maron, O. V. Ozerov,
D. Bourissou, J. Am. Chem. Soc. 2008, 130, 16729–16738; i) S.
Bontemps, H. Gornitzka, G. Bouhadir, K. Miqueu, D. Bouris-
sou, Angew. Chem. 2006, 118, 1641; Angew. Chem. Int. Ed.
2006, 45, 1611–1614; j) S. Bontemps, M. Sircoglou, G. Bou-
hadir, H. Puschmann, J. A. K. Howard, P. W. Dyer, K. Miqueu,
D. Bourissou, Chem. Eur. J. 2008, 14, 731–740; k) M. Sircog-
lou, S. Bontemps, M. Mercy, N. Saffon, M. Takahashi, G. Bou-
hadir, L. Maron, D. Bourissou, Angew. Chem. 2007, 119, 8737;
Angew. Chem. Int. Ed. 2007, 46, 8583–8586; l) S. Bontemps, M.
Sircoglou, G. Bouhadir, H. Puschmann, J. A. K. Howard, P. W.
Dyer, K. Miqueu, D. Bourissou, Chem. Eur. J. 2008, 14, 731–
740; m) S. Bontemps, G. Bouhadir, W. Gu, M. Mercy, C.-H.
Chen, B. M. Foxman, L. Maron, O. Ozerov, D. Bourissou, An-
gew. Chem. 2008, 120, 1503; Angew. Chem. Int. Ed. 2008, 47,
1481–1484.
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[12] S. L. Granville, G. C. Welch, D. W. Stephan, Inorg. Chem. 2012,
51, 4711–4721.
[13] H. Kameo, Y. Hashimoto, H. Nakazawa, Organometallics
2012, 31, 3155–3162.
[14] a) I. R. Crossley, A. F. Hill, A. C. Willis, Organometallics 2006,
25, 289–299; b) V. K. Landry, J. G. Melnick, D. Buccella, K.
Pang, J. C. Ulichny, G. Parkin, Inorg. Chem. 2006, 45, 2588–
2597; c) A. F. Hill, G. R. Owen, A. J. P. White, D. J. Williams,
Angew. Chem. 1999, 111, 2920; Angew. Chem. Int. Ed. 1999,
38, 2759–2761; d) I. R. Crossley, A. F. Hill, Organometallics
Eur. J. Inorg. Chem. 0000, 0–0
12
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[24] Y. Jiang, J. Hess, T. Fox, H. Berke, J. Am. Chem. Soc. 2010,
132, 18233–18247.
[25] J. Vergnaud, M. Grellier, G. Bouhadir, L. Vendier, S. Sabo-
Etienne, D. Bourissou, Organometallics 2008, 27, 1140–1146.
[26] a) K. Seyferth, R. Taube, J. Organomet. Chem. 1984, 262, 179–
190; b) K. Seyferth, R. Taube, J. Organomet. Chem. 1982, 229,
275–279.
ian, J. B. Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gom-
perts, R. E. Stratmann, O. Yazyev, A. J. Austin, R. Cammi, C.
Pomelli, J. W. Ochterski, P. Y. Ayala, K. Morokuma, G. A.
Voth, P. Salvador, J. J. Dannenberg, V. G. Zakrzewski, S. Dap-
prich, A. D. Daniels, M. C. Strain, O. Farkas, D. K. Malick,
A. D. Rabuck, K. Raghavachari, J. B. Foresman, J. V. Ortiz, Q.
Cui, A. G. Baboul, S. Clifford, J. Cioslowski, B. B. Stefanov,
G. Liu, A. Liashenko, P. Piskorz, I. Komaromi, R. L. Martin,
D. J. Fox, T. Keith, M. A. Al-Laham, C. Y. Peng, A. Nanayak-
kara, M. Challacombe, P. M. W. Gill, B. Johnson, W. Chen,
M. W. Wong, C. Gonzalez, J. A. Pople, Gaussian 03, revision
D.01, Gaussian, Inc., Wallingford, CT, 2003.
[27] Agilent Technologies, Yarnton, UK, 2011.
[28] R. C. Clark, J. S. Reid, Acta Crystallogr., Sect. A 1995, 51, 887–
897.
[29] G. M. Sheldrick, Acta Crystallogr., Sect. A 2008, 64, 112–122.
[30] L. Farrugia, J. Appl. Crystallogr. 1999, 32, 837–838.
[31] A. L. Spek, J. Appl. Crystallogr. 2003, 36, 7–13.
[32] M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria,
M. A. Rob, J. R. Cheeseman, J. A. Montgomery Jr., T. Vreven,
K. N. Kudin, J. C. Burant, J. M. Millam, S. S. Iyengar, J. Tom-
asi, V. Barone, B. Mennucci, M. Cossi, G. Scalmani, N. Rega,
G. A. Petersson, H. Nakatsuji, M. Hada, M. Ehara, K. Toyota,
R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda,
O. Kitao, H. Nakai, M. Klene, X. Li, J. E. Knox, H. P. Hratch-
[33]
[34]
P. J. Hay, W. R. Wadt, J. Chem. Phys. 1985, 82, 270–283.
T. H. Dunning Jr., P. J. Hay, Modern Theoretical Chemistry,
Plenum, New York, 1976.
[35] R. Ditchfield, W. J. Hehre, J. A. Pople, J. Chem. Phys. 1971, 54,
724–728.
Received: December 30, 2012
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