Zirconium complexes supported by an N-perfluoro-arylated diamidopyridyl ligand: Synthesis of hydrazinediido complexes

Article abstract of DOI:10.1021/ic401603y

The N-perfluoro-phenylated pyridyldiamine H₂N₂ ^PFPN_py (1) has been prepared by a palladium-catalyzed coupling of hexafluorobenzene and the diamine (H₂NCH ₂)₂C(CH₃)(2-C₅H₄N) using the palladacycle trans-di(μ-acetato)bis[o-(di-o-tolylphosphino)benzyl] palladium(II) as catalyst. Reactions of H₂N₂ ^PFPN_py and Zr(NMe₂)₄ at room temperature or 90 C led to the complexes [(N^PFPN₂ ^TFAPN_py)ZrF(NMe₂)] (2) and [(N₂ ^TFAPN_py)ZrF₂] (3) in which one or two dimethylamido groups replaced one or two ortho fluorine atoms of the pentafluorophenyl groups in the ligand. Reaction of Me₃SiX (X = Cl, I) with [(N₂^TFAPN_py)ZrF₂] (3) resulted in the formation of mixed halogenated complexes [(N₂ ^TFAPN_py)ZrFI] (4) and [(N₂^TFAPN _py)ZrFCl] (5) in which the axially bound fluorido ligand is substituted. Reaction of [(N₂^TFAPN_py)ZrF ₂] (3) with LiNHNPh₂ afforded the monohydrazido(1-) complex [(N₂^TFAPN_py)ZrF(NHNPh₂)] (6) which was converted to the dimeric fluoro-potassium bridged hydrazinediido complex [Zr(N₂^TFAPN_py)FNNPh₂K] ₂ (7) using KHMDS. The corresponding reaction with LiHMDS yielded the monomeric, donor free complex [Zr(N₂^TFAPN _py)NNPh₂] (8).

Full text of DOI:10.1021/ic401603y

Article
pubs.acs.org/IC
Zirconium Complexes Supported by an N-Perfluoro-Arylated
Diamidopyridyl Ligand: Synthesis of Hydrazinediido Complexes
Solveig A. Scholl, Gudrun T. Plundrich, Hubert Wadepohl, and Lutz H. Gade*
Anorganisch-Chemisches Institut, Universitat Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
̈
S
* Supporting Information
PFP
ABSTRACT: The N-perfluoro-phenylated pyridyldiamine H2N2
N (1) has been prepared
py
by a palladium-catalyzed coupling of hexafluorobenzene and the diamine (H2NCH2)2C(CH3)(2-
C5H4N) using the palladacycle trans-di(μ-acetato)bis[o-(di-o-tolylphosphino)benzyl]palladium-
PFP
(II) as catalyst. Reactions of H2N2
N
and Zr(NMe2)4 at room temperature or 90 °C led to
py
TFAP
TFAP
the complexes [(NPFPN2
N )ZrF(NMe2)] (2) and [(N2
N )ZrF2] (3) in which one or
py
py
two dimethylamido groups replaced one or two ortho fluorine atoms of the pentafluorophenyl
TFAP
groups in the ligand. Reaction of Me3SiX (X = Cl, I) with [(N2
N )ZrF2] (3) resulted in the
py
TFAP
TFAP
formation of mixed halogenated complexes [(N2
N )ZrFI] (4) and [(N2
in which the axially bound fluorido ligand is substituted. Reaction of [(N2
N )ZrFCl] (5)
py
py
TFAP
N )ZrF2] (3) with LiNHNPh2 afforded the
py
TFAP
monohydrazido(1−) complex [(N2
N )ZrF(NHNPh2)] (6) which was converted to the dimeric fluoro-potassium bridged
N )FNNPh2K]2 (7) using KHMDS. The corresponding reaction with LiHMDS yielded the
py
TFAP
hydrazinediido complex [Zr(N2
py
TFAP
monomeric, donor free complex [Zr(N2
N )NNPh2] (8).
py
hydrazinediido−zirconium complex. Interest in transition
metal hydrazides has been due to the role they are thought
to play in the stoichiometric and catalytic reduction of
dinitrogen to ammonia.9 In contrast to group 6 metals, the
chemistry of group 4 metal hydrazinediido complexes has only
been studied systematically during the past decade and has
given rise to a variety of stoichiometric and catalytic reaction
patterns.10,11
INTRODUCTION
■
The choice of the appropriate ancillary ligand is crucial for
controlling the reactivity of a metal complex, in particular for
the stabilization of reactive molecular fragments in the
coordination sphere of a metal. This applies both to the
development of new molecular catalysts and to the stabilization
of reactive molecular fragments at the metal with the aim of
gaining an understanding of the key active species and
intermediates involved in catalytic reactions. For complexes of
high-valent Lewis acidic early transition metals polydentate
amido ligands have found widespread application in this
context.1 These not only shield and thus protect a well-defined
sector of the coordination sphere but also predefine the
structures of the “reactive sector”. For the group 4 metal,
diamido-donor ligands,2 in which the two negatively charged
amido groups are combined with a neutral ligating unit, have
proved to be particularly suited for the synthesis of complexes
containing reactive MN bonds.3
RESULTS AND DISCUSSION
■
Synthesis of the N-Pentafluorophenylated Protioli-
PFP
gand H2N2
N
(1). Reaction of the diamine (H2NCH2)2C-
py
(CH3)(2-C5H4N)4b (“H2N2 Npy”) and hexafluorobenzene in
the presence of K2CO3, as had been described previously by
Schrock and co-workers6 for the synthesis of a tris(N-
pentafluorophenylated) triaminoamine ligand, did not result
in the formation of the target product. We therefore chose a
Buchwald−Hartwig-type amination12 to couple the aryl groups
to the amine nitrogen atoms. Since the application of the most
widely employed catalyst system, the combination of Pd2(dba)3
and racBINAP, proved not to be successful for the coupling of
bromopentafluorobenzene and (H2NCH2)2C(CH3)(2-
C5H4N),13 we tested the palladacycle trans-di(μ-acetato)bis[o-
(di-o-tolylphosphino)benzyl]palladium(II) developed by Beller
and Herrmann as precatalyst.14 Unexpectedly, the reaction of
the diamine with bromopentafluorobenzene resulted in a
product mixture because both carbon−bromine and carbon−
H
In particular, the tridentate diamidopyridyl ligand
[N2 Npy]2−4 has given rise to a rich organometallic chemistry
PFP
of group 4 metal imido and hydrazido complexes and their
derivatives.3 Their characteristic MN bond reactivity arises
from the high polarity of this unit compared to the transition
metals in middle of the d-block.5 In order to raise the Lewis
acidity of the metal center we became interested in the
possibility of preparing a diamidopyridyl ligand of this type
bearing pentafluorinated aryl groups. Given previous reports of
the chemistry of N-fluoroarylated amido compounds,6−8 we
expected reactive behavior which differed from that of the
silylated and arylated diamidopyridyl ligands studied to date.
In this work we report the synthesis of a pentafluorophenyl
fluorine bond activation occurred. When hexafluorobenzene
PFP
was used instead, the desired protioligand H2N2
N (1) was
py
obtained in moderate yields (37%, Scheme 1), the major side
substituted [N2 Npy]2− ligand, its transformation upon reaction
R
Received: June 25, 2013
Published: August 13, 2013
with [Zr(NMe2)4], and the stepwise synthesis of
© 2013 American Chemical Society
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PFP
Scheme 1. Synthesis of the Pentafluorinated Ligand H2N2
N (1)
py
Scheme 2. Ortho Fluorido/Amido Exchange in the Ancillary Diamidopyridyl Ligand 1 upon Reaction with [Zr(NMe2)4]
product being the mono pentafluorophenylated compound
which could be recycled. This is a relatively rare case in which
palladium-catalyzed C−N coupling is carried out with the aryl
groups of the coordinating dimethylamido unit and one singlet
with an integral of six for the freely rotating dimethylamino
group of the ligand. An exchange of this type was first reported
by Schrock and co-workers for a related molybdenum
complex7a and has been reported since for several other
fluoride.15 The infrared spectra of the ligand H2N2 Npy (1) as
PFP
well as of the complexes discussed below display strong bands
at ν = 800 cm−1 to 1200 cm−1, respectively, which are due to
systems.7,8 Upon heating compound 2 to 90 °C for six days the
the C−F vibrations.16
Reaction of H2N2
formation of the difluorido complex [(N2
N )ZrF2] 3 was
py
TFAP
PFP
N
(1) with [Zr(NMe2)4]: Transfer
py
observed (Scheme 2). Complex 3 could also be prepared
PFP
of a Me2N Group to the Ortho Position of the N-C6F5
directly by adding ligand H2N2
N
py
(1) to [Zr(NMe2)4]
PFP
Rings. The reaction of H2N2
N
py
(1) and [Zr(NMe2)4] at
followed by application of the same reaction conditions.
The 19F NMR spectrum of 3, displaying four signals in the
aromatic region (−150 ppm to −177 ppm) as well as two
singlets at 72.5 ppm and 102.5 ppm, was consistent with a Cs-
symmetric compound. An X-ray diffraction study revealed that
two ortho fluorine atoms of the aryl rings had been replaced by
dimethylamido groups. The molecular structure of 7-fold
coordinated complex 3 is shown in Figure 1 along with selected
bond lengths and angles.
room temperature afforded [(N2PFPN2
N )ZrF(NMe2)]
TFAP
py
(2) as a yellow product in moderate yield. The H and 19F
NMR spectra indicate a nonsymmetrical complex, which is
reflected in the observation of eight signals in the 19F NMR
spectrum, seven in the aromatic region (−145 ppm to −180
ppm) and one at +72 ppm, indicating a Zr-bound fluorine. This
can be explained by the exchange of one of the four ortho
fluorine atoms in the N-C6F5 rings by a dimethylamido group
originating from the tetraamido zirconium starting material.
1
The coordination geometry is best described as distorted
pentagonal bipyramidal with the amido nitrogen atoms and the
dimethylamino groups of the N-aryl rings of the ancillary ligand
1
This assignment is also supported by the H NMR spectrum
showing two separate singlet resonances for both methyl
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Figure 1. Molecular structure of complex 3. Selected bond lengths (Å)
and angles (deg): Zr(1)−N(1)/N(2) = 2.161(4)/2.152(4), Zr(1)−
N(3) = 2.370(4), Zr(1)−N(4)/N(5) = 2.507(4)/2.529(4), Zr(1)−
F(1)/F(2) = 1.978(2)/1.957(3); F(2)−Zr(1)−F(1) = 102.6(1),
F(2)−Zr(1)−N(3) = 177.2(1); N(4)−Zr(1)−N(5) = 135.6(1).
Hydrogen atoms are omitted for clarity.
Figure 2. Molecular structure of complex 4. Selected bond lengths (Å)
and angles (deg): Zr−N(1) = 2.1320(13), Zr−N(3) = 2.3321(18),
Zr−N(4) = 2.5262(13), Zr−F(6) = 1.974(1), Zr−I = 2.8951(2);
F(6)−Zr−I = 110.75(4), N(3)−Zr−I = 167.96(4); N(4A)−Zr−N(4)
= 132.05(6). Hydrogen atoms are omitted for clarity.
occupying four equatorial positions. The Zr(1)−N(1)/N(2)
bonds are slightly longer (by 0.1−0.2 Å) than in related
complexes with methyl-substituted aryl rings,11g,13a which can
possible isomers of the fluorohydrazido(1−) complex (6)
(Scheme 3).
be explained by the electron withdrawing effect of the fluorine
substituents. The pyridyl unit of the N2
N
py
ligand and one
The 1H NOESY NMR spectrum of 6 revealed cross
relaxation between the NH proton and the dimethylamino
groups at the aryl substituents of the ligand. Furthermore no
cross relaxation was observed between the NH proton and the
hydrogen atoms of the pyridyl fragment of the ligand. This
pattern indicates an axial coordination of the hydrazido(1−)
fragment as depicted in Scheme 3.
TFAP
fluorido ligand occupy the axial sites. The Zr−N(3) and the
Zr−F bond lengths are in good agreement with those reported
in literature.7,8
Halide exchange in 3 was attempted by reaction with a slight
excess of trimethylsilyl chloride or trimethylsilyl iodide
(Scheme 2).17 In both cases only the mixed halogenated
complexes were isolated in which the axially bonded fluorido
ligand was replaced by the chloride or iodide. Even a large
excess of the trimethylsilyl halide reagent did not result in the
replacement of the equatorially bound fluorine atom as
demonstrated by 19F NMR spectroscopy (in both reactions
only one signal between 90 ppm and 105 ppm corresponding
to one zirconium bound fluorine atom was observed).
Conversion of the hydrazido(1−) zirconium complex 6 to a
hydrazinediido complex was attempted by reaction with
potassium hexamethyldisilazide in benzene. In view of the
peripheral Me2N-donor functions in the supporting ligand, no
1
additional neutral donor was added. Although the H NMR
spectrum indicated abstraction of the NH proton by the base,
the 19F NMR spectrum of the isolated product 7 was consistent
with the presence of a fluoride ligand bonded to Zr. An X-ray
diffraction study revealed a dimeric structure in which the two
zirconium complex units are formally KF adducts, in which the
potassium cations associated with one of the hydrazido units
are coordinated by the fluoraryl rings of the other complex
fragment. The molecular structure of 7 is depicted in Figure 3,
along with selected bond lengths and angles.
Coordination of each Zr atom is 7-fold by the diamidopyridyl
ligand (including the dimethylamino groups), the hydrazine-
diido unit, and one fluorido atom. The molecular structure is
therefore approximately pentagonal bipyramidal with the
pyridyl fragment of the ligand and the near-linear hydrazine-
diido ligand occupying the axial positions. The Zr−N(6) and
the N(6)−N(7) bond lengths are in good agreement with
those found for other zirconium hydrazinediido complexes.11
The two amido and the two dimethylamine nitrogen atoms as
well as the remaining fluorido ligand are coordinated in the
equatorial sites. The Zr−N(1)/N(2) bond lengths are longer
[up to 0.2 Å] than in the halogenated complexes 3−5,
indicating a weaker coordination of the ligand to the zirconium
atom.
Single crystals suitable for X-ray diffraction were obtained
TFAP
from both complexes [(N2
N )ZrFI] (4) and
py
TFAP
[(N2
N )ZrFCl] (5) (see Supporting Information). The
py
general structural features of both complexes are very similar,
including Cs molecular symmetry. The molecular structure of
TFAP
[(N2
N )ZrFI] (4) is shown in Figure 2. The zirconium is
py
7-fold coordinated by all nitrogen atoms of the facially
coordinating diamidopyridyl ligand including the dimethylami-
no groups and both halogenides. The axial positions are
occupied by the pyridine nitrogen of the ancillary ligand and
the iodine atom (respectively the chlorine atom in 5), the
“trans” angle differing significantly from linearity (N(3)−Zr−I
167.96(4)° and N(3)−Zr−Cl 169.06(4)°, respectively).
Synthesis and Structural Characterization of Hydra-
zido−Zirconium Complexes. The synthesis of hydrazinedii-
do zirconium complexes stabilized by the diamidopyridyl ligand
with amido N-aryl substituents has been achieved by addition
of the corresponding hydrazine to a solution of bisamido
Xyl
complex [(N2 Npy)Zr(NMe2)2] along with an excess of 4-
dimethylaminopyridine (DMAP).11h,i Herein we describe the
synthesis of hydrazinediido complexes containing the o-NMe2
substituted N-fluoroarylated ligand described in this work.
It did not prove possible to induce KF elimination from
compound 7, in order to obtain the salt-free hydrazinediido
complex, either by extended heating in toluene or K+
TFAP
Reaction of the difluorido complex [(N2
N )ZrF2] (3) with
py
1 molar equiv of LiNHNPh2 selectively led to one of the
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TFAP
Scheme 3. Synthesis of {N2
N } Zirconium Hydrazido Complexes
py
complexation with crown ethers or cryptants. However,
reacting the hydrazido(1−) zirconium complex 6 with 1
equiv of lithium hexamethyldisilazide yielded the monomeric
hydrazinediido complex 8 directly, the complete dehydrohalo-
genation being readily followed by 1H and 19F NMR
spectroscopy. This may be due to the greater Lewis acidity of
Li+ compared to K+ and the ability of the former to assist
fluoride abstraction. Notably, an additional donor molecule like
pyridine, hitherto employed in all isolated zirconium
hydrazinediides, is not required.
The molecular structure of 8, as determined by single crystal
X-ray diffraction, is depicted in Figure 4. The zirconium atom is
6-fold coordinated, with five coordination sites being occupied
by the diamidopyridyl ligand including the dimethylamino
groups and the remaining position by the hydrazinediido
fragment. In contrast to previously reported systems featuring
an arylated diamidopyridyl ligand, the hydrazinediido ligand
occupies an equatorial site which we attribute to the geometric
constraints imposed by the pentadentate amido-donor
ligand.11j,k The Zr−N(6) bond length and the Zr−N(6)−
N(7) angle are in good agreement with those of other
hydrazinediido zirconium complexes.18 The binding of the
dimethylamino groups to the zirconium is stronger compared
to the complexes discussed so far, as reflected in the shorter
Zr(1)−N(4)/N(5) bonds, and may result from the lower
coordination number of six (Zr−N(4)/N(5) values: 3,
2.507(4)/2.529(4); 4, 2.526(1); 5, 2.481(1); 7, 2.522(1)/
2.565(2); 8, 2.436(1)/2.454(1)). Notably, one of the
dimethylamino groups occupies an axial position, although
the structural constraints of the ligand backbone lead to a
considerable deviation of the “trans” angle N(4)−Zr−N(3).
by reaction with [Zr(NMe2)4]. These additional donor
functions proved to be important in the dehydrohalogenation
of the monohydrazido(1−) complex 6 using LiHMDS giving
the first donor free hydrazinediido zirconium complex. Further
exploitation of this type of ancillary ligand is part of current and
future work in our lab.
EXPERIMENTAL SECTION
■
General Experimental Procedures. All manipulations of air and
moisture sensitive materials were carried out under an inert
atmosphere of dry argon [argon 5.0] using standard Schlenk and
glovebox techniques [glovebox: Unilab-2000, M. Braun]. Argon was
dried over phosphorus pentoxide [Sicapent, Merck Chemicals] before
use. Solvents were predried over molecular sieves and dried over Na/K
alloy [pentane, diethyl ether] or K [toluene, THF, hexane, benzene]
and distilled, or dried over activated alumina columns using a solvent
purification system [M. Braun SPS 800] and stored over potassium or
sodium mirrors [THF] in Teflon valve ampules. Deuterated solvents
were purchased from Deutero GmbH, dried over K [benzene-d6,
THF-d8], vacuum distilled, and stored in Teflon valve ampules under
argon. Samples for NMR spectroscopy were prepared under argon in 5
mm Wilmad tubes equipped with J. Young Teflon valves. NMR
spectra were recorded on Bruker DRX200, Bruker Avance II 400, or
Bruker Avance III 600 (with QNP-CryoProbe) NMR spectrometers.
NMR spectra are quoted in ppm and were referenced internally
relative to the residual protio-solvent [1H] or solvent [13C] resonances
or externally to 15NH3 [15N] and C19FCl3 [19F]. Where necessary,
NMR assignments were confirmed by the use of two-dimensional
1H−1H, 1H−19F, and 1H−13C correlation experiments. Infrared
spectra of Nujol mulls were recorded on a Varian 3100 FT-IR.
Elemental analyses were recorded by the analytical service of the
Heidelberg Chemistry Department. The ligand precursor
H
(H2NCH2)2C(CH3)(2-C5H4N) (“H2N2 Npy”) was prepared accord-
ing to a published procedure.4b Ph2NNH2 was prepared from the
hydrochloride salt purchased from Acros, and purified by column
chromatography (over silica, dichloromethane) prior to use.
LiNHNPh2 was synthesized according to the literature.19 All other
reagents were obtained from commercial sources [Acros/Thermo
Fischer, ABCR/Strem and Sigma-Aldrich] and used as received unless
explicitly stated. Trimethylsilyl reagents were degassed and stored in a
glovebox.
CONCLUSION
■
In this work we have reported a new access to pentafluoro-
phenyl substituted amine ligands using Pd coupling with
hexafluorobenzene and trans-di(μ-acetato)bis[o-(di-o-
tolylphosphino)benzyl]palladium(II) as catalyst. Moreover,
the resulting protioligand H2N2
PFP
N
py
(1) was subsequently
transformed to a potentially pentacoordinate supporting ligand
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Figure 4. Molecular structure of complex 8. Selected bond lengths (Å)
and angles (deg): Zr(1)−N(1)/N(2) = 2.157(1)/2.251(1), Zr(1)−
N(4)/N(5) = 2.436(1)/2.454(1), Zr(1)−N(6) = 1.895(1), N(6)−
N(7) = 1.379(2); N(7)−N(6)−Zr(1) = 169.7(1), N(3)−Zr(1)−N(4)
= 150.35(5), N(3)−Zr(1)−N(5) 104.65(5), N(6)−Zr(1)−N(3) =
90.47(6).
3
3
NH), 6.50 (dd, JH5pyH4py = 7.8 Hz, JH5pyH6py = 4.9 Hz, 1H, H5py),
3
3
6.79 (d, JH3pyH4py = 8.0 Hz, 1H, H3py), 6.97 (td, JH4pyH3py/H5py = 7.8
4
3
Hz, JH4pyH6py = 1.9 Hz, 1H, H4py), 8.31 (dt, JH6pyH5py = 4.9 Hz,
4JH6pyH5py = 0.8 Hz, 1H, H6py). {1H} 13C NMR (C6D6, 150.92 MHz,
296 K): δ = 22.4 (CH3), 45.7 (C-CH3), 54.7 (CH2), 121.3 (C3py),
122.1 (C5py), 124.6 (CPh‑NH), 132.9, 135.0 (C‑mPh/pPh‑F), 136.9 (C4py),
138.0, 139.6 (C‑oPh/mPh‑F), 148.8 (C6py), 163.6 (C2py).15N NMR
(C6D6, 60.84 MHz, 296 K): δ = 41.6 (NH), 307.3 (Npy).19F NMR
3
4
(C6D6, 376.27 MHz, 296 K): δ = −171.4 (tt, Jp‑Fm‑F = 22.9, Jp‑Fo‑F
=
3
6.1, 2F, F‑pPh), −164.8 (t, Jm‑Fo‑F/p‑F = 20.7, 4F, F‑mPh), −158.7 (d,
3Jo‑Fm‑F = 22.3, 4F, F‑oPh). IR (Nujol, NaCl, cm−1): ν = 3440 w, 3307 w,
2963 vs, 2726 w, 2611 w, 1659 w, 1595 w, 1521 m, 1460 s, 1377 s,
1305 w, 1262 w, 1170 w, 1073 w, 1025 w, 970 w, 827 w, 721 m. HR-
MS (FAB): [M]+ = C21H21F14N3, calcd 498.1028, found 498.1030;
diff, 0.2 mmu. Elemental analysis, C21H13F10N3: calcd C 50.72, H 2.63,
Figure 3. Molecular structure of complex 7. Top: The dimer
TFAP
[Zr(N2
N )FNNPh2K]2. Bottom: A monomeric complex unit.
py
Selected bond lengths (Å) and angles (deg): Zr−N(1)/N(2) =
2.722(1)/2.242(1), Zr−N(4)/N(5) = 2.522(1)/2.565(1), Zr−N(3)
2.492(1), Zr−N(6) = 1.896(1), N(6)−N(7) = 1.386(2), K−F(3) =
2.730(1); N(7)−N(6)−Zr = 175.0(1), N(6)−Zr−N(3) = 172.94(5),
N(4)−Zr−N(5) = 143.44(4), F(4A)−K−N(1) = 93.80(3). Hydrogen
atoms are omitted for clarity.
N 8.45; found C 50.76, H 2.71, N 8.40.
H2N2
mono‑PFP
N . 1H NMR (C6D6, 600.13 MHz, 296 K): δ = 1.03 (s,
py
2 2
3H, CH3), 2.60 (d, JHH = 12.5 Hz, 1H, CHH), 3.20 (d, JHH = 12.5
2
3
Hz, 1H, CHH), 3.55 (dd, JHH = 12.5 Hz, JCH2NH = 4.8 Hz, 1H,
2
3
CHH(PFP)), 3.66 (dd, JHH = 12.4 Hz, JCH2NH = 6.5 Hz, 1H,
CHH(PFP)), 6.31 (s, 1H, NH(PFP)), 6.54−6.56 (m, 1H, H5py), 6.96
3
PFP
(d, JH3pyH4py = 8.0 Hz, 1H, H3py), 7.02−7.52 (m, 1H, H4py), 8.34 (d,
Preparation of Compounds. H2N2
N
(1). Under an
py
3JH6pyH5py = 4.3 Hz, 1H, H6py). {1H} 13C NMR (C6D6, 150.92 MHz,
296 K): δ = 23.5 (CH3), 45.7 (C-CH3), 51.0 (CH2NH2), 55.1
(CH2(PFP)), 121.4 (C3py), 121.4 (C5py), 125.8 (CPFP‑NH), 136.3
(C4py), 137.6, 139.3 (C‑oPh/mPh‑F), 148.9 (C6py), 164.9 (C2py), C‑pPh‑F n.
o. 15N NMR (C6D6, 60.84 MHz, 296 K): δ = 46.7 (NH), 310.6 (Npy),
NH2 n. o. 19F NMR (C6D6, 376.27 MHz, 296 K): δ = −174.4 (tt,
atmosphere of argon to a solution of trans-di(μ-acetato)bis[o-(di-o-
tolylphosphino)benzyl]palladium(II) (92 mg, 0.10 mmol, 2.0 mol %),
cesium carbonate (8.15 g, 25 mmol, 5.0 equiv), and lithium bromide
(0.17 g, 2.0 mmol, 0.4 equiv) in toluene (50 mL) were added the
diamine MeC(2-C5H4N)(CH2NH2)2 (0.83 g, 5.0 mmol, 1.0 equiv)
and hexafluorobenzene (1.86 g, 10.0 mmol, 2.0 equiv), and the
reaction mixture was stirred for 72 h under reflux. Subsequently, the
solvent was removed under reduced pressure. The brown residue was
redissolved in diethyl ether (50 mL) the resulting solution was washed
with water (2 × 30 mL) and then with a saturated aqueous solution of
NaCl (2 × 30 mL). The combined organic phases were dried over
Na2SO4 and evaporated. The residue was purified by column
chromatography on silica (pentane/diethyl ether 7:3, Rf = 0.23) to
4
3Jp‑Fm‑F = 22.5, Jp‑Fo‑F = 7.4, 1F, F‑pPh), −164.8 to −165.6 (m, 2F,
F
‑mPh), −159.9 (m, 2F, F‑oPh).
[Zr(NPFPNTFAPNpy)(NMe2)F] (2). Tetrakisdimethylamidozirconium-
PFP
(IV) (266 mg, 1.0 mmol, 1.0 equiv) and H2N2
N
(500 mg, 1.0
py
mmol, 1.0 equiv) were dissolved in toluene and stirred overnight.
Subsequently, the solvent was removed under reduced pressure and
the crude product was washed with pentane to obtain [Zr-
(NPFPNTFAPNpy)(NMe2)F] as a pale red solid. Yield: 0.43 g (62%).
1H NMR (C6D6, 600.13 MHz, 296 K): δ = 1.05 (s, 3H, CH3), 2.11 (s,
give the product as a light brown solid. Yield: 0.9 g (36%). The mono
mono‑PFP
arylated ligand H2N2
N could be retrieved in the chromato-
py
2
3H, CPh-N-CH3), 2.65 (bs, 6H, Zr-N-(CH3)2), 2.87 (d, JHH = 11.8
graphic workup and appeared after the fractions of 1 together with the
unreacted starting material (characterization data given below). The
mixture of both could be reused as educt for synthesis of the diarylated
Hz, 1H, CHH), 2.90−2.96 (m, 3H, CPh-N-CH3), 3.04 (dd, 2JHH = 12.3
Hz, 5JHF‑Ar = 5.4 Hz, 1H, CHH), 4.02 (d, 2JHH = 11.8 Hz, 1H, CHH),
4.44 (dd, 2JHH = 12.3 Hz, 5JHF‑Ar = 6.6 Hz, 1H, CHH), 6.45−6.50 (m,
compound.
3
PFP
1H, H5py), 6.79 (d, JH3pyH4py = 8.1 Hz, 1H, H3py), 6.96 (td,
H2N2
N
(1). 1H NMR (C6D6, 600.13 MHz, 296 K): δ = 1.02 (s,
py
2 3
3JH4pyH3/5py = 7.8 Hz, 4JH4pyH6py = 1.7 Hz, 1H, H4py), 8.98 (d, 3JH6pyH5py
= 5.2 Hz, 1H, H6py).13C {1H} NMR (C6D6, 150.92 MHz, 296 K): δ =
3H, CH3), 3.39 (dd, JHH = 12.6 Hz, JCH2NH = 6.0 Hz, 2H, CHH),
2
3
3.49 (dd, JHH = 12.9 Hz, JCH2NH = 7.9 Hz, 2H, CHH), 4.86 (s, 2H,
10162
dx.doi.org/10.1021/ic401603y | Inorg. Chem. 2013, 52, 10158−10166

Inorganic Chemistry
Article
24.5 (s, CH3), 41.7 (bs, Zr-N-(CH3)2), 46.6 (m, CPh-N-CH3), 46.9 (s,
CPh-N-CH3), 47.3 (d, C-CH3), 62.0 (d, CH2), 63.0 (d, CH2), 121.4 (s,
C3py), 122.0 (s, C5py), 123.8 (CF‑Ar), 132.1 (CF‑Ar), 133.4(CF‑Ar), 134.9
(CF‑Ar), 136.6 (CF‑ar), 137.4 (CF‑Ar), 138.2 (CF‑Ar), 139.0 (CF‑Ar), 139.3
(CF‑Ar), 139.6 (s, C4py), 141.3 (CF‑Ar), 142.8 (CF‑Ar), 145.1 (CF‑Ar),
147.6 (d, C6py), 163.3 (s, C2py).15N NMR (C6D6, 60.84 MHz, 296 K):
δ = 135.9 (CH2-N-Ar), 151.0 (CH2-N-Ar), 183.5 (Ar-N-Me2), 282.7
(Npy), n.b. (Zr-NMe2). 19F NMR (C6D6, 376.27 MHz, 296 K): δ =
−176.7 (td, 3JFF = 22.8 Hz, 4JFF = 8.8, 1F, Fo/m), −171.5 (tt, 3JFF = 21.8
days at room temperature. Subsequently, the solvent was removed
under vacuum and the crude product was washed with pentane. The
complex was obtained as a pale yellow powder. Yield: 45 mg (89%).
1H NMR (C6D6, 399.89 MHz, 296 K): δ = 0.97 (s, 3 H, CH3), 2.18 (s,
6 H, N(CH3)2), 2.83 (dd, 2JHH = 12.2 Hz, 4JHH = 2.5 Hz, 2 H, CHH),
3.29−3.40 (m, 6 H, N(CH3)2), 4.35−4.44 (m, 2 H, CHH), 6.47 (t,
3
3JH5pyH6py/H4py = 6.6 Hz 1 H, H5py), 6.76 (d, JH3pyH4py = 8.3 Hz, 1 H,
H3py), 6.92−6.98 (m, 1 H, H4py), 8.76−8.82 (m, 1 H, H6py). 13C {1H}
NMR (C6D6, 100.56 MHz, 296 K): δ = 24.6 (CH3), 45.8 (C-CH3),
46.6, 46.9 (N-(CH3)2), 62.0 (CH2), 62.1 (CH2), 122.2 (C5py), 122.4
(C3py), 140.1 (C4py), 146.7 (C6py), 162.4 (s, C2py), Cq [C-F and C-N]
could not be observed. 15N NMR (C6D6, 60.84 MHz, 296 K): δ =
164.0 (CH2-Nar), 280.2 (Npy), NMe2 n.o. 19F NMR (C6D6, 376.27
MHz, 296 K): δ = −174.3 (td, 3JFF = 21.9 Hz, 4JFF = 7.2 Hz, 2 F, Fp or
Fm), −160.3 (t, 3JFF = 21.0 Hz, 2 F, Fm or Fp) −155.6 to −155.4 (m, 2
F, Fm adjacent to C-NMe2), −150.7 (dt, 3JFoFm = 21.9 Hz, 4JFoFp = 5.5
Hz, 2 F, Fo), 91.4 (s, 1 F, Zr-F). IR (Nujol, NaCl, cm−1): ν = 2962 vs,
2857 vs, 2723 w, 1600 m, 1464 s, 1377 m, 1295 w, 1260 m, 1167 w,
1096 w, 1017 w, 991 m, 960 m, 802 m, 722 m. Elemental analysis,
C25H23ClF9N5Zr: calcd C 43.44, H 3.35, N 10.13; found C 43.15, H
3.60, N 10.28.
Hz, 4JFF = 5.9 Hz, 1 F, CpPh-F (N-Pfb)), −167.0 (m, 2F, CoPh-F, CmPh
-
F (N-Pfb)), −159.4 (m, 1F, 1 Fm), −158.9 (m, 1F, FCCNMe2),
−153.3 (m, 2F, CoPh-F, CmPh-F (N-Pfb)), −149.7 (m, 1F, Fo), +71.2 (t,
4JFH = 27.4 Hz, 1F, Zr-F). IR (Nujol, NaCl, cm−1): ν = 2924 vs, 2854
vs, 1462 s, 1377 m, 1260 m, 1101 m, 1059 m, 1015 m, 799 m.
Elemental analysis, C25H23F10N5Zr: calcd C 44.50, H 3.44, N 10.38;
found C 43.95, H 3.57, N 10.27.
TFAP
[Zr(N2 Npy)F2] (3). Tetrakisdimethylamidozirconium(IV) (399
PFP
mg, 1.5 mmol, 1.0 equiv) and H2N2
N
(742 mg, 1.5 mmol, 1.0
py
equiv) were dissolved in toluene and heated for four days at 90 °C.
Subsequently, the solvent was removed under vacuum and the crude
product was washed with pentane. The complex was obtained as a
yellow powder. Yield: 906 mg (90%). 1H NMR (THF-d8, 600.13
MHz, 296 K): δ = 1.64 (s, 3H, CH3), 2.59 (s, 6H, N(CH3)2), 3.21−
3.31 (m, 8H, 2 CHH + 6 N(CH3)2), 4.34−4.43 (m, 2H, CHH), 7.52
TFAP
TFAP
[Zr(N2 Npy)FNHNPh2] (6). To a solution of [Zr(N2
N )F2]
py
(1.6 g, 2.35 mmol, 1.0 equiv) in benzene (5 mL) was added lithium
diphenylhydrazide (538 mg, 2.82 mmol, 1.2 equiv), and the reaction
mixture was stirred for one day at 90 °C. The solvent was removed by
filtration, the crude product was washed with pentane, and the
3
3
(t, JH5pyH4py = 6.5 Hz, 1H, H5py), 7.81 (d, JH3pyH4py = 8.1 Hz, 1H,
3
H3py), 8.09 (t, JH4pyH3/5py = 7.7 Hz, 1H, H4py), 9.25−9.31 (m, 1H,
H6py). 13C {1H} NMR (THF-d8, 150.92 MHz, 296 K): δ = 25.1
(CH3), 45.2 (N-(CH3)2), 46.6 (C-CH3), 46.8 (N-(CH3)2), 62.5
(CH2), 62.6 (CH2), 122.2, 122.5 (CAr-N), 123.3 (C3py), 123.6 (C5py),
125.9 (Car), 131.0 (CAr), 132.6 (CAr), 137.0 (CAr), 138.6 (Car), 140.0
(CAr), 140.9 (CAr), 141.6 (C4py), 142.6 (CAr), 145.3 (CAr), 146.9
(CAr),148.2 (C6py), 163.4 (C2py). 15N NMR (THF-d8, 60.84 MHz, 296
K): δ = 151.7 (CH2-N-Ar), 281.5 (Npy), n.b. (NMe2). 19F NMR
1
complex was obtained as an orange powder. Yield: 1.2 g (61%). H
NMR (C6D6, 399.89 MHz, 296 K): δ = 1.07 (s, 3 H, CH3), 2.21 (s, 6
2
H, N(CH3)2), 2.84 (d, JHH = 12.3 Hz, 2 H, CHH), 3.29−3.39 (m, 6
H, N(CH3)2), 4.16−4.29 (m, 2 H, CHH), 5.62 (s, 1 H, NH), 6.51 (t,
3JH5pyH6py/H4py = 6.4 Hz 1 H, H5py), 6.78−6.88 (m, 3 H, H3py
+
H
p‑Phenyl), 6.98 (t, 3JH4pyH3py/5py = 7.6 Hz, 1 H, H4py), 7.04−7.22 (m, 8
H, Hm‑Phenyl + Ho‑Phenyl overlay with residual signal of C6D6), 8.89−8.94
(m, 1 H, H6py). 13C {1H} NMR (C6D6, 100.56 MHz, 296 K): δ = 24.8
(CH3), 45.8 (C-CH3), 45.3 (N-(CH3)2), 47.9 (N-(CH3)2), 62.8
(CH2), 62.9 (CH2), 118.1 (C3py), 119.6 (CHar, Co/m‑Phenyl), 121.7
(CHAr, Cp‑Phenyl), 122.1 (C5py), 125.6 (C-N(CH3)2), 129.5 (CHAr,
Co/m‑Phenyl), 139.1 (C4py), 146.9 (C6py), 150.6 (NH-N-CPhipso), 162.8
(C2py), CAr−F n.o., C−N−CPh‑Ligandipso n.o. 15N NMR (C6D6, 40.52
MHz, 296 K): δ = 117.0 (NHNPh2), 156.9 (CH2Nar), 197.8 (NH),
284.0 (Npy), NMe2 n.o. 19F NMR (C6D6, 376.27 MHz, 296 K): δ =
(THF-d8, 376.27 MHz, 296 K): δ = −178.8 (td, 3JFF = 22.3 Hz, 4JFF
=
3
4
7.8, 2F, Fp or Fm), −162.6 (t, JFF = 20.8 Hz, JFF = 1.4 Hz, 2F, Fm or
Fm), −158.6 to (−158.4) (m, 2F, Fm adjacent to C-NMe2), −151.2 (d,
3JFF = 21.7 Hz, 2F, Fo), +70.5 (s, 1F, Zr-F), +102.5 (s, 1F, Zr-F). IR
(Nujol, NaCl, cm−1): ν = 3131 w, 2853 vs, 1607 s, 1498 s, 1376 m,
1295 w, 1259 m, 1164 m, 1104 m, 1064 w, 994 m, 844 m, 721 m, 673
m. Elemental analysis, C25H23F10N5Zr: calcd C 44.50, H 3.44, N 10.38;
found C 44.02, H 3.74, N 9.92.
TFAP
TFAP
[Zr(N2 Npy)FI] (4). To a solution of [Zr(N2
N )F2] (100 mg,
py
3
4
−175.7 (td, JFpFm = 22.3 Hz, JFpFo = 7.5 Hz, 2 F, Fp), −160.7 (t,
3JFmFp, FmFo = 21.3 Hz, 2 F, Fm), −155.9 to −155.7 (m, 2 F, Fo), −151.1
to −150.9 (m, 2 F, Fm adjacent to C-NMe2), 54.5 (s, 1 F, Zr-F). IR
(Nujol, NaCl, cm−1): ν = 2921 vs, 2853 s, 1780 w, 1601 m, 1461 s,
1377 m, 1293 w, 1259 m, 1168 m, 110 m, 1063 w, 993 m, 959 m, 845
m, 798 w, 721 w. Elemental analysis, C37H34F9N7Zr: calcd C 52.97, H
4.08, N 11.69; found C 52.83, H 4.14, N 11.40.
0.15 mmol, 1.0 equiv) in toluene (10 mL) was added TMSI (102 μL,
0.75 mmol, 5.0 equiv), and the reaction mixture was stirred for two
days at room temperature. Subsequently, the solvent was removed
under vacuum and the crude product was washed with pentane. The
complex was obtained as a pale yellow powder. Yield: 104 mg (90%).
1H NMR (THF-d8, 600.13 MHz, 296 K): δ = 1.69 (s, 3H, CH3), 2.52
(s, 6H, N(CH3)2), 3.29−3.25 (m, 2H, CHH), 3.42−3.50 (m, 6H,
N(CH3)2), 4.46−4.54 (m, 2H, CHH), 7.58 (t, 3JH5pyH4py = 6.5 Hz, 1H,
TFAP
TFAP
[Zr(N2 Npy)FNNPh2K] (7). To a solution of [Zr(N2
N )-
py
H5py), 7.86 (d, 3JH3pyH4py = 8.2 Hz, 1H, H3py), 8.15 (td, 3JH4pyH3py/5py
=
FNHNPh2] (215 mg, 0.26 mmol, 1.0 equiv) in benzene (5 mL) was
added potassium hexamethyldisilazide (52 mg, 0.26 mmol, 1.0 equiv),
and the reaction mixture was stirred for one day at room temperature.
Subsequently, the solvent was removed under vacuum and the crude
product was washed with pentane. The complex was obtained as a
4
7.8 Hz, JH4pyH6py = 1.6 Hz, 1H, H4py), 9.14−9.19 (m, 1H, H6py). 13C
{1H} NMR (THF-d8, 150.92 MHz, 296 K): δ = 24.9 (CH3), 46.8 (C-
CH3), 47.6, 48.3 (N-(CH3)2), 62.8 (CH2), 62.9 (CH2), 122.2, 122.4
(CAr-N), 123.8 (C3py), 123.9 (C5py), 127.4 (CAr-F), 132.0 (CAr-F),
133.6 (CAr-F), 136.0 (CAr-F), 137.4 (C-N-(CH3)2), 137.6 (CAr‑F),
140.5 (CAr-F), 140.5 (C4py), 144.2 (CAr-F), 145.9 (CAr-F), 147.9
(C6py), 163.3 (C2py). 15N NMR (THF-d8, 60.84 MHz, 296 K): δ =
277.9 (Npy), 173.2 (CH2-N-Ar), n.b. (N(CH3)2)). 19F NMR (THF-d8,
376.27 MHz, 296 K): δ = −176.3 (td, 3JFF = 21.7 Hz, 4JFF = 7.0, 2F, C-
F), −162.8 to (−162.7) (m, 2F, C-F), −156.7 to −156.6 (m, 2F,
CH2NCCF), −152.3 to −152.2 (m, 2F, F adjacent to C-NMe2),
+104.0 (s, 1F, Zr-F). IR (Nujol, NaCl, cm−1): ν = 3120 w, 2899 vs,
2852 s, 1606 s, 1466 s, 1378 s, 1292 m, 1260 m, 1161 s, 1094 m, 1067
m, 1013 m, 992 m, 954 m, 837 s, 763 m, 675 m, 649 m. Elemental
analysis, C25H23F9IN5Zr: calcd C 38.37, H 2.96, N 8.95; found C
38.08, H 3.26, N 8.78.
1
light brown powder. Yield: 80 mg (36%). H NMR (C6D6, 600.13
MHz, 296 K): δ = 1.18 (s, 6 H, 2*CH3), 2.18 (s, 12 H, 2*N(CH3)2),
2
2.98 (d, JHH = 11.7 Hz, 4 H, 2*CHH), 3.08−3.17 (bs, 12 H,
2*N(CH3)2), 3.73−3.86 (m, 4 H, 2*CHH), 6.52 (d, 3JHo‑Phenyl/Hm‑Phenyl
3
= 7.7 Hz, 8H, 8*Ho‑Phenyl), 6.58 (t, JH5pyH6py/H4py = 6.3 Hz 2 H,
3
2*H5py), 6.71 (t, JHp‑Phenyl/Hm‑Phenyl = 7.4 Hz, 4 H, 4*Hp‑Phenyl), 6.89
3
(d, JH3py/H4py = 8.0 Hz, 2 H, 2*H3py), 6.98−7.05 (m, 10 H,
8*Hm‑Phenyl + 2*H3py), 9.37−9.40 (m, 2H, 2*H6py). 13C {1H} NMR
(C6D6, 150.91 MHz, 296 K): δ = 24.3 (CH3), 44.9, 45.0, 45.1, 46.1,
46.1 (C-CH3, N-(CH3)2), 63.7, 63.8 (CH2), 118.1 (Co‑Phenyl), 119.8
(Cp‑Phenyl), 120.1, 120.1 (C5py, C3py), 127.1 (C-N(CH3)2), 128.6
(Cm‑Phenyl)136.9 (C4py), 148.2, 148.4 (N-CPhipso), 147.9 (C6py), 163.0
(C2py), Car‑F n.o., C−N−CPh‑Ligandipso n.o. 15N NMR (C6D6, 40.52
MHz, 296 K): δ = 103.8 (CH2-Nar), 163.8 (NNPh2), 289.9 (Npy),
NMe2 n.o., NNPh2 n.o. 19F NMR (C6D6, 376.27 MHz, 296 K): δ =
TFAP
TFAP
[Zr(N2 Npy)FCl] (5). To a solution of [Zr(N2
N )F2] (50 mg,
py
0.07 mmol, 1.0 equiv) in toluene (3 mL) was added TMSCl (19 μL,
0.15 mmol, 2.0 equiv), and the reaction mixture was stirred for two
10163
dx.doi.org/10.1021/ic401603y | Inorg. Chem. 2013, 52, 10158−10166

Inorganic Chemistry
Article
Table 1. Details of the Crystal Structure Determinations of 3·0.5benzene, 4·2benzene, 5, 7, and 8·0.5toluene
3·0.5benzene
4·2benzene
5
7
8·0.5toluene
formula
C28H26F10N5Zr
713.76
C37H23D12F9IN5Zr
950.89
C25H23ClF9N5Zr
691.15
C88H82F18K2N14Zr2
1938.31
C40.50H37F8N7Zr
864.99
Mr
cryst syst
monoclinic
P21/c
monoclinic
P21/m
monoclinic
P21/m
triclinic
triclinic
space group
P1
̅
P1
̅
a/Å
8.973(2)
14.563(3)
22.387(5)
8.33711(8)
23.5742(2)
9.73416(10)
8.33527(4)
18.16024(9)
9.30851(5)
10.21010(10)
13.21438(13)
16.79443(15)
93.1084(8)
95.7719(8)
111.0070(9)
2094.62(4)
1
11.2275(2)
13.7650(3)
14.1485(3)
112.625(2)
105.1498(18)
101.2234(18)
1838.17(8)
2
b/Å
c/Å
α/deg
β/deg
97.987(4)
109.294(1)
110.9131(6)
γ/deg
V/Å3
2898(1)
4
1805.68(3)
2
1316.21(1)
2
Z
F000
1436
932
692
988
882
dc/Mg·m−3
X-radiation, λ/Å
μ/mm−1
1.636
1.749
1.744
1.537
1.563
Mo Kα, 0.71073
0.472
Mo Kα, 0.71073
1.242
Mo Kα, 0.71073
0.610
Mo Kα, 0.71073
0.444
Cu Kα, 1.5418
3.173
max, min transm factors
data collect. temp/K
θ range/deg
0.9631, 0.8838
100(2)
1.0000, 0.8027
110(2)
0.947, 0.911
115(2)
0.988, 0.952
110(2)
0.965, 0.749
110(2)
2.3 to 25.1
3.3 to 29.0
3.2 to 27.9
3.2 to 32.4
3.6 to 71.8
index ranges (indep set) h, k, l −10...10, 0...17,
−11...11, −31...31,
−10...11, −23...23,
−15...15, −19...19,
−13...13, −16...16,
a
b
b
b
b
0...26
−13...13
−12...12
−25...24
−17...17
reflns measured
unique [Rint]
60392
141732
76245
73620
63489
5160 [0.1317]
3529
4794 [0.0687]
4234
3184 [0.0323]
3028
14155 [0.0373]
13179
7012 [0.0424]
6619
obsd [I ≥ 2σ(I)]
params refined
GOF on F2
375
258
205
574
534
1.047
1.054
1.067
1.174
1.047
R indices [F > 4σ(F)] R(F),
wR(F2)
0.0543, 0.1070
0.0221, 0.0432
0.0189, 0.0507
0.0417, 0.0812
0.0245, 0.0588
R indices (all data) R(F),
0.0955, 0.1187
0.0306, 0.0458
0.0206, 0.0517
0.0470, 0.0831
0.0271, 0.0599
wR(F2)
diff density: max, min/e·Å−3
0.465, −0.677
0.503, −0.385
0.384, −0.341
0.686, −0.807
0.467, −0.429
a
b
Independent set. Complete set.
3
4
−177.4 (td, JFpFm = 21.4 Hz, JFpFo = 9.4 Hz, 4 F, 4*Fp), −164.0 (t,
3JFmFp,Fo = 21.4 Hz, 4 F, 4*Fm) −160.6 to −160.2 (m, 4 F, 4*Fo),
−148.8 to −148.5 (m, 4 F, 4*Fm benachbart zu C-NMe2), −17.3 to
−17.1 (m, 2 F, 2*Zr-F). IR (Nujol, NaCl, cm−1): ν = 2917 vs, 2853 s,
1886 w, 1605 m, 1465 s, 1377 m, 1294 w, 1259 m, 1164 m, 1099 m,
1068 w, 1017 m, 995 m, 955 w, 843 m, 722 w, 674 w. Elemental
analysis, C74H66F18K2N14Zr2: calcd C 50.67, H 3.79, N 11.18; found C
50.44, H 4.45, N 10.60.
of intensity data were collected at low temperature with a Bruker AXS
Smart 1000 CCD diffractometer (Mo Kα radiation, sealed tube,
graphite monochromator) (3·0.5benzene) or an Agilent Technologies
Supernova-E CCD diffractometer (Mo or Cu Kα radiation, microfocus
tube, multilayer mirror optics) (all others). Data were corrected for air
and detector absorption and Lorentz and polarization effects;20,21
absorption by the crystal was treated with a semiempirical multiscan
method,22−24 analytically,21,25 or numerically (Gaussian grid).21 The
structures were solved by direct methods with dual-space recycling26
(3·0.5benzene), by the heavy atom method combined with structure
expansion by direct methods applied to difference structure factors27
(5), or by the charge flip procedure28 (all others) and refined by full-
matrix least-squares methods based on F2 against all unique
reflections.29 All non-hydrogen atoms were given anisotropic displace-
ment parameters. Hydrogen atoms were placed at calculated positions
and refined with a riding model. When found necessary, disordered
groups and/or solvent molecules where subjected to suitable geometry
and adp restraints. Crystals of 3·0.5benzene were twinned; after
detwinning (approximate twin fractions 0.76:0.24) refinement was
carried out against all observations involving domain 1. In addition,
due to severe disorder, electron density attributed to solvent of
crystallization was removed from this structure with the BYPASS
procedure,30 as implemented in PLATON (SQUEEZE).31 Partial
structure factors from the solvent masks were included in the
TFAP
TFAP
[Zr(N2 Npy)NNPh2] (8). To a solution of [Zr(N2
N )-
py
FNHNPh2] (75 mg, 0.1 mmol, 1.0 equiv) in benzene (2 mL) was
added lithium hexamethyldisilazide (19 mg, 0.1 mmol, 1.0 equiv), and
the reaction mixture was stirred for one day at 60 °C. Subsequently,
the solvent was removed under vacuum and the crude product was
washed with pentane. The complex was obtained as a light brown
powder. Yield: 20 mg (25%). 1H NMR (C6D6, 600.13 MHz, 296 K): δ
= 1.01 (s, 3H, CH3), 2.58 (bs, 6H, N(CH3)2), 2.74 (bs, 6H,
3
N(CH3)2), 3.38−3.65 (m, 4H, CH2), 6.38 (t, JH5pyH6py/H4py = 6.5 Hz,
3
1H, H5py), 6.73 (d, JH3py/H4py = 8.1 Hz, 1H, H3py), 6.78 (t,
3JHp‑Phenyl/Hm‑Phenyl = 6.8 Hz, 4 H, 2*Hp‑Phenyl), 6.83−6.89 (m, 1H,
3
H4py), 7.13 (d, JHArHAr = 8.0 Hz, 4 H, 4*Hm‑Phenyl), 7.31 (d,
3JHo‑Phenyl/Hmeta‑Phenyl = 8.0 Hz, 4 H, 4*Ho‑Phenyl), 9.31 (d, JH6py/H5py
=
3
5.1 Hz, 1H, H6py). 13C {1H} NMR (C6D6, 150.91 MHz, 296 K): δ =
22.5 (CCH3), 41.8, 42.2, 44.3, 44.5 (N-(CH3)2), 45.3 (C-CH3), 62.0,
63.5 (CH2), 117.5 (Co‑Phenyl), 119.0 (Cp‑Phenyl), 119.2, 119.3 (C5py,
C3py), 126.8 (Cm‑Phenyl), 137.3 (C4py), 146.4 (CPhipso), 149.4 (C6py),
161.7 (C2py), CAr−F n.o., Cipso-N n.o. 19F NMR (C6D6, 376.27 MHz,
296 K): δ = −160.6 to −159.8 (m, 2F), −150.2 to −149.2 (m, 2F). IR
(Nujol, NaCl, cm−1): ν = 3273 w, 2854 s, 2598 w, 1593 m, 1494 m,
1463 s, 1377 s, 1260 m, 1253 w, 1048 w, 976 m, 798 w, 722 m.
X-ray Crystal Structure Determinations. Crystal data and
details of the structure determinations are listed in Table 1. Full shells
refinement as separate contributions to Fobs
.
ASSOCIATED CONTENT
■
S
* Supporting Information
Figure of the molecular structure of complex 5 and selected
bond parameters. CIF files giving crystallographic data for
10164
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Inorganic Chemistry
Article
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compounds 3, 4, 5, 7, 8. This material is available free of charge
via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
■
Corresponding Author
*Fax: +49-6221-545609. E-mail: lutz.gade@uni-hd.de.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
This work has been supported by the Deutsche Forschungsge-
meinschaft (SFB 623, TP A7). We thank Sabine Stolz and
Alexander Kochan for help with the ligand synthesis.
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