Zirconium complexes having a chiral phosphanylamide in the co-ordination sphere

Article abstract of DOI:10.1039/b503956h

The chiral phosphanylamido ligand, {N(CHMePh)(PPh₂)} ^-, has been introduced into co-ordination chemistry. As starting material the oily amines HN(R-*CHMePh)(PPh₂) (1a) and HN(S-*CHMePh)(PPh₂) (1b) were used. To

Full text of DOI:10.1039/b503956h

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F U L L P A P E R
Zirconium complexes having a chiral phosphanylamide in the
co-ordination sphere
Michal Wiecko, Denise Girnt, Marcus Rasta¨tter, Tarun K. Panda and Peter W. Roesky*
Institut fu¨r Chemie, Freie Universita¨t Berlin, Fabeckstraße 34-36, 14195, Berlin, Germany.
E-mail: roesky@chemie.fu-berlin.de
Received 18th March 2005, Accepted 27th April 2005
First published as an Advance Article on the web 12th May 2005
−
The chiral phosphanylamido ligand, {N(CHMePh)(PPh2)} , has been introduced into co-ordination chemistry. As
starting material the oily amines HN(R-*CHMePh)(PPh2) (1a) and HN(S-*CHMePh)(PPh2) (1b) were used. To
=
reconfirm their absolute structure, 1b was oxidized with H2O2 in air to obtain HN(S-*CHMePh)(P( O)Ph2) (2) as a
solid compound. The solid-state structure of 2 was established by single-crystal X-ray diffraction. The lithium salts of
both enantiomers Li{N(R-*CHMePh)(PPh2)} (3a) and Li{N(S-*CHMePh)(PPh2)} (3b) were prepared by
deprotonation reaction of 1a,b. Compounds 3a,b were further reacted with zirconocen dichloride to give the chiral
5
2
5
2
metallocenes [(g -C5H5)2Zr(Cl){g -N(R-*CHMePh)(PPh2)}] (4a) and [(g -C5H5)2Zr(Cl){g -N(S-*CHMePh)(PPh2)}]
(4b). In an alternative approach to give chiral zirconium compounds, the neutral amine 1b was reacted with
2
[(PhCH2)4Zr] to give the enantiomeric pure complex [(PhCH2)3Zr{g -N(S-*CHMePh)(PPh2)}] (5). The solid-state
structures of all zirconium complexes were determined by single-crystal X-ray diffraction.
Introduction
The renaissance of amido complexes, which are well known for
more than thirty years, started some years ago, when a number of
research groups realized that amides can be used as analogues for
the well known cyclopentadienyl ligand in d- and f-transition-
metal chemistry.1 Beside this analogy, amido ligands are used
today for the design of new transition-metal compounds having
well defined reaction centers. Whereas for the vast number of
amido complexes organic amines were used as starting materials,
recently, there has been a significant research effort in employing
inorganic amines and imines. Especially P–N systems such
as monophosphanylamides (R2PNRꢀ),2–5 diphosphanylamides
((Ph2P)2N),3,6,7 phosphoraneiminato (R3PN),8 phosphinimi-
nomethanides ((RNPRꢀ2)CH),9–14 phosphiniminomethandiides
((RNPRꢀ2)C)15–19 and diiminophosphinates ((R2P(NRꢀ))20 were
used as ligands. These works have shown, that some of the
early transition-metal complexes having P–N ligands in the co-
Scheme 1
ordination sphere, may not only exhibit unusual co-ordination
modes1 but also can be used for a number of catalytic transfor-
mations such as polymerization reactions.15,21
(Fig. 1). The bond length (P–O 149.21(7) pm, P–N 163.35(9) pm)
and angles (O–P–N 116.60(5)◦) of compound 2 are as expected.
Previously, we have reported on the reactivity of two P–
N ligands in lanthanide and zirconium chemistry. Now, we
are interested to introduce a chiral phosphanylamide into
early transition-metal chemistry. As starting material we used
the phosphanylamine HN(CHMePh)(PPh2) (Scheme 1), which
was introduced by Brunner into co-ordination chemistry. The
amine, which usually co-ordinates via the phosphorus atom
to the centre metal, was basically used in late transition-metal
chemistry.22 To the best of our knowledge the phosphanylamide
−
{N(CHMePh)(PPh2)} has not been used as a ligand previously.
Results and discussion
Both enantiomers of the chiral phosphanylamine HN(R-
*CHMePh)(PPh2) (1a) and HN(S-*CHMePh)(PPh2) (1b) were
synthesised according to literature methods from enantiomeri-
cally pure a-methylbenzylmethanamine and Ph2PCl;23 1a,b are
oily compounds. To assure that the stereogenic centre is not
affected by this procedure one enantiomer was oxidized with
Fig. 1 Solid-state structure of 2 showing the atom labeling scheme,
omitting hydrogen atoms. Selected distances (pm) and angles (◦):
P–O 149.21(7), P–N 163.35(9), P–C15 180.49(9) P–C9 180.59(10),
N–C1 146.99(12); O–P–N 116.60(5), O–P–C(15) 113.40(4), N–P–C(15)
103.02(4), O–P–C(9) 108.68(4), N–P–C(9) 107.11(4), C15–P–C(9)
107.49(4), C1–N–P 120.54(7).
=
H2O2 in air to obtain HN(S-*CHMePh)(P( O)Ph2) (2) as
a solid compound (Scheme 1). Compound 2 was described
earlier.24 We established the solid-state structure by single-crystal
X-ray diffraction simply to determine the absolute configuration
The new lithium compounds Li{N(R-*CHMePh)(PPh2)} (3a)
and Li{N(S-*CHMePh)(PPh2)} (3b) were readily prepared by
T h i s j o u r n a l i s
T h e R o y a l S o c i e t y o f C h e m i s t r y 2 0 0 5
D a l t o n T r a n s . , 2 0 0 5 , 2 1 4 7 – 2 1 5 0
2 1 4 7
©

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5
treatment of the corresponding enantiomer of 1 with 1 equiva-
lent of n-butyllithium in THF (Scheme 1). Compounds 3a,b were
obtained as air-sensitive powders, which were characterized by
1H and 31P NMR spectroscopy. In comparison to 1 the 1H NMR
signals of 3 show only a slight shift. Most significantly the CH3
group (d 1.08) is shifted 0.4 ppm upfield upon metallation of the
the starting material [g -Cp2ZrCl2] (d 6.50).27 The doublet is a
result of the coupling to the phosphorus atom. In the 1H NMR
−
spectra the {N(CHMePh)(PPh2)} ligands show a characteristic
doublet for the CH3 group (d 1.66 ppm) and a quartet for the CH
proton (d 4.93 ppm), which both are shifted downfield compared
to 3a,b. Also characteristic is the 31P NMR spectrum. At room
ligand. In the 31P{ H} NMR spectra of 3 (d 48.8 ppm) the signal
temperature 4a,b each show one signal in the 31P{ H} NMR
1
1
is shifted downfield relative to 1 (d 34.4 ppm).
spectrum (d −19.5 ppm), which are significantly shifted relative
Reaction of 3a,b with zirconocene dichloride in a 1 : 1
molar ratio in THF, followed by crystallization from THF–n-
pentane yield the expected enantiomerically pure complexes
to 3 (d 41.5).
Recently, other chiral zirconium complexes were prepared by a
protolysis of [(PhCH2)4Zr] and amines such as aminopyridines28
and aminooxazolines29 to give chiral (at metal) complexes.
Inspired by these reactions, [(PhCH2)4Zr] was treated with 1b to
5
2
5
[(g -C5H5)2Zr(Cl){g -N(R-*CHMePh)(PPh2)}] (4a) and [(g -
2
C5H5)2Zr(Cl){g -N(S-*CHMePh)(PPh2)}] (4b) (Scheme 1). The
2
new complexes have been characterized by standard ana-
lytical/spectroscopic techniques, and the solid-state structure
was established by single-crystal X-ray diffraction (Fig. 2).
The enantiomers 4a,b crystallise in the chiral monoclinic
space group P21 having two molecules in the unit cell. The
give [(PhCH2)3Zr{g -N(S-*CHMePh)(PPh2)}] (5) (Scheme 1).
Compound 5 is a chiral complex but the metal is not the stereo-
genic centre. The reaction of [(PhCH2)4Zr] with 1b is not a clean
reaction. We suggest that a mixture of compounds is obtained,
in which the phosphanylamide is attached in different ratios to
the metal centre. Out of this mixture we could so far only obtain
compound 5 as crystalline product. Compound 5 is an air- and
moisture-sensitive compound, which has been characterized by
1H and 31P NMR spectroscopy as well as elemental analysis. The
1H NMR spectrum of 5 shows the characteristic doublet for the
CH3 group (d 1.45 ppm) and a quartet for the CH proton (d
−
{N(CHMePh)(PPh2)} ligand is co-ordinated to the zirconium
2
atom in a chelating (g ) fashion. The structure reveals a
pseudo-five-fold co-ordination sphere of the ligands around the
zirconium atom if the ring centroids of the cyclopentadienyl
rings are considered as co-ordination positions. The P and N
5
atoms are co-ordinated to the (g -C5H5)2ZrCl fragment, and
−
the N, P, Zr and Cl atoms are nearly coplanar as shown by
4.94 ppm) of the {N(CHMePh)(PPh2)} ligand and the expected
a torsion angle N–P–Zr–Cl of 1.52(1)◦ (4a) and 1.36(1)◦ (4b).
signals for the benzyl groups. In the 31P{ H} NMR spectrum one
1
5
A similar geometry is observed in the achiral compounds [g -
signal is observed at d −7.0 ppm.
2
Cp2Zr(Cl){g -N(SiMe3)P(H)N(SiMe3)2}], which was obtained
The molecular structure of 5 was also confirmed by X-
ray diffraction (Fig. 3). Compound 5 crystallises in the chiral
monoclinic space group P21 having two molecules in the unit
5
25
=
by reaction of Me3SiN P–N(SiMe3)2 with [g -Cp2Zr(Cl)H]
and in [g -Cp2Zr(Cl){g -N(PPh2)2}].26 The Zr–N bond lengths of
5
2
−
4a,b (219.27(14) pm (4a), 219.85(10) pm (4b)) are shorter than in
cell. As observed for 4a,b the {N(CHMePh)(PPh2)} ligand is
5
2
2
[g -Cp2Zr(Cl){g -N(SiMe3)P(H)N(SiMe3)2}] (226.7(3) pm) and
co-ordinated to the zirconium atom in a chelating (g ) fashion
5
2
[g -Cp2Zr(Cl){g -N(PPh2)2}] (224.9(5) pm) whereas the Zr–P
bond distances of 4a,b (265.2 (1) pm (4a), 265.0(1) pm (4b))
are in the range of previously reported compounds (265.2(1) pm
showing a Zr–N distance of 209.6(2) pm and Zr–P distance of
263.20(9) pm. The Zr–N bond distance is about 10 pm shorter
than those observed for 4a,b. We interpret this difference on the
basis of an altered electrostatic Zr–N interaction caused by a
difference of electron density on the zirconium atom. Whereas,
in compounds 4a,b the cyclopentadienyl ligands donate some
negative charge on to the metal no comparable interaction is
available in compound 5. This is also supported by the co-
ordination mode of the benzyl groups. Whereas two of the three
5
2
in [g -Cp2Zr(Cl){g -N(SiMe3)P(H)N(SiMe3)2}] and 264.9(2) pm
5
in [g -Cp2Zr(Cl)N(PPh2)2]). The Cg–Zr (Cg = Cp-ring centroid)
distances Cg1–Zr 225.4(10) pm (4a), 225.4(10) pm (4b) and Cg2–
Zr 225.2(4) pm (4a), 225.5(4) pm (4b), respectively) and the angle
Cg1–Zr–Cg2 (125.95(1)◦) are in the expected ranges.
1
benzyl ligands are g co-ordinated the third one additionally
shows an g p-bonding of the phenyl ring to the centre metal.
2
Fig. 2 Solid-state structures of 4a (left) and 4b (right) showing
the atom labeling scheme, omitting hydrogen atoms. Selected dis-
tances (pm) and angles (◦): 4a: Zr–N 219.27(14), Zr–P 265.2(1),
Zr–Cl 253.86(5), N–C100 148.0(2), N–P1 163.23(15), P–C1 182.2(2),
P–C7 184.0(2), Zr–Cg1 225.4(10), Zr–Cg2 225.2(4); N–Zr–Cl 85.44(1),
N–Zr–P 38.09(10), C100–N–P 123.09(12), C100–N–Zr 150.49(12),
P–N–Zr 86.38(6), N–P–C1 112.34(8), N–P–C7 110.66(8), C1–P–C7
103.70(8), N–P–Zr 55.68(5), C1–P–Zr 122.42(6), C7–P–Zr 133.84(6),
Cg1–Zr–Cg2 124.73(10), Cg1–Zr–N 116.92(10), Cg1–Zr–Cl 101.26(10).
4b: Zr–N 219.85(10), Zr–P 265.0(1), Zr–Cl 254.75(5), N–P 163.94(10),
P–C1 182.02(12), P–C7 184.02(12), Zr–Cg1 225.4(10), Zr–Cg2 225.5(4);
N–Zr–Cl 85.44(3), N–Zr–Cl 85.67(4), N–Zr–P 37.94(10), C100–N–P
123.07(8), C100–N–Zr 150.79(8), P–N–Zr 86.10(4), N–P–C1 112.26(6),
N–P–C7 110.57(5), C1–P–C7 103.59(5), N–P–Zr 55.81(4), C1–P–Zr
122.42(4), C7–P–Zr 133.95(4), Cg1–Zr–Cg2 124.67(1), Cg1–Zr–N
116.91(1), Cg1–Zr–Cl 101.19(1) (Cg = Cp-ring centroid).
Fig.
3 Solid-state structure of 5 showing the atom labeling
scheme, omitting hydrogen atoms. Selected distances (pm) and an-
gles (◦): Zr–N 209.6(2), Zr–P 263.20(9), Zr–C21 229.1(3), Zr–C22
254.2(3), Zr–C23 287.9(1), Zr–C28 230.6(2), Zr–C35 227.8(3), N–P
166.4(2); N–Zr–P 39.18(6), N–Zr–C21 103.81(10), N–Zr–C28 94.47(12),
N–Zr–C22 115.60(10), N–Zr–C35 127.79(10), C21–Zr–C22 34.21(10),
C21–Zr–C28 128.56(12), C21–Zr–C35 101.44(11), C22–Zr–C28
94.60(11), C22–Zr–C35 111.00(10), C28–Zr–C35 104.16(9), C22–Zr–P
141.23(7), C21–Zr–P 111.42(8), C28–Zr–P 112.86(11), C35–Zr–P
89.01(8), C22–C21–Zr 82.5(2), C29–C28–Zr 108.3(2), C36–C35–Zr
115.8(2), C1–N–P 127.8(2), P–N–Zr 88.09(10), N–P–Zr 52.73(8),
C1–N–Zr 143.8(2).
1
The H NMR spectra show a sharp doublet for the protons
of the Cp unit, which is shifted upfield (d 5.95) compared with
2 1 4 8
D a l t o n T r a n s . , 2 0 0 5 , 2 1 4 7 – 2 1 5 0

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1
This p-bonding is a result of the electron-deficient character of
the centre metal. The distances of the zirconium atom to these
p-bonded carbon atoms are Zr–C22 254.2(3) pm and Zr–C23
287.9(1) pm. As a result of the p-bonding one phenyl ring is
significant bent towards the metal centre. The angles between the
zirconium atom, the benzyl CH2 group and the ipso carbon atom
of the phenyl ring are 108.3(2)◦ (C29–C28–Zr) and 115.8(2)◦
2.65 g (85.3%)◦. Yield 3b: 2.93 g (94.5%). H NMR (d8-THF,
3
400 MHz, 25 C): d 1.08 (d, 3H, CH3, J(H–H) = 6.4 Hz),
3
4.30 (q, 1H, CH, J(H–H) = 6.4 Hz), 6.86–7.32 (m, 15H, Ph).
◦
31P{ H} NMR (d8-THF, 161.7 MHz, 25 C): d 48.8.
1
[(g5-Cp)2Zr(Cl){g2-N(R-*CHMePh)(PPh2)}] (4a) and [(g5-
Cp)2Zr(Cl){g2-N(S-*CHMePh)(PPh2)}] (4b). 10 mL of THF
was condensed at −196 ◦C onto a mixture of 480 mg (1.65 mmol)
Cp2ZrCl2 and 0.515 g (1.65 mmol) of 3 and the magenta
suspension was stirred for 48 h at room temperature. The solvent
was then evaporated in vacuo and toluene (25 mL) condensed
onto the mixture. Then, the solution was filtered and the solvent
was removed from the toluene extract. The remaining solid was
washed with n-pentane (10 mL) and dried in vacuo. Finally, the
product was crystallised from boiling toluene. Yield (4a): 740 mg
1
(C36–C35–Zr) for the g -co-ordinated benzyl groups, whereas
it is lowered to 82.5(2)◦ (C22–C21–Zr) in the g -co-ordinated
3
ligand.
Conclusions
In summary, we have introduced the chiral phosphany-
−
lamido {N(CHMePh)(PPh2)} ligand into co-ordination chem-
1
(80%) Yield (4b): 790 mg (85%) H NMR (d8-THF, 400 MHz,
istry. First, the lithium salts of both enantiomers Li{N(R-
*CHMePh)(PPh2)} and Li{N(S-*CHMePh)(PPh2)} were pre-
pared by a deprotonation reactions. These compound were
further reacted with zirconocene dichloride to give the chi-
◦
3
25 C): d 1.66 (3H, d, CH3, J(H–H) = 7.43 Hz), 4.93 (1H,
3
q, CH), 5.95 (d, 10H, Cp, J(H, P) = 17.5 Hz), 7.0–7.5 (m,
◦
15H, Ph). 31P{ H} NMR (d8-THF, 161.7 MHz, 25 C): d −19.5.
C30ClH29NPZr (561.21): calc.: C, 64.20; H, 5.21; N, 2.50; found:
C, 63.97; H, 5.29; N, 2.47%.
1
5
2
ral metallocenes [(g -C5H5)2Zr(Cl){g -N(R-*CHMePh)(PPh2)}]
5
2
and [(g -C5H5)2Zr(Cl){g -N(S-*CHMePh)(PPh2)}]. In an al-
ternative approach to give zirconium compounds, the neutral
amine HN(S-*CHMePh)(PPh2) was reacted with [(PhCH2)4Zr]
[(PhCH2)3Zr{g2-N(S-*CHMePh)(PPh2)}] (5). 20 mL of
toluene was condensed at −196 ◦C onto a mixture 498 mg
(1.09 mmol) [(PhCH2)4Zr]. The solution was warmed to room
temperature. Then, 666 mg (2.18 mmol) of 1b in 2 mL of toluene
were added to the solution. The mixture was stirred for 17 h at
room temperature. Slowly a brown precipitate and an orange
solution are formed. Then, the solution was filtered and the
solvent was removed from the filtrate. The remaining oily brown
product was washed with n-pentane (2 × 10 mL) and dried
in vacuo. Finally, the product was crystallised from toluene–n-
pentane (1 : 3). Yield: 100 mg (14%). 1H NMR (C6D6, 400 MHz,
20.9 ◦C): d 1.45 (d, 3H, CH3), 2.00–2.11 (br, 6H, CH2), 4.94 (q,
1H, CH), 6.63–6.65 (d, 4H, Ph), 6.92–7.13 (m, 22H, Ph),◦7.35–
2
to give the enantiomerically pure complex [(PhCH2)3Zr{g -N(S-
*CHMePh)(PPh2)}].
Experimental
General considerations
All manipulations of air-sensitive materials were performed with
the rigorous exclusion of oxygen and moisture in flame-dried
Schlenk-type glassware either on a dual manifold Schlenk line,
interfaced to a high vacuum (10−4 Torr) line, or in an argon-
filled M. Braun glove-box. Ether solvents (tetrahydrofuran and
diethyl ether) were predried over Na wire and distilled under
nitrogen from K (THF) or Na wire (diethyl ether) in benzophe-
none ketyl prior to use. Hydrocarbon solvents (toluene and n-
pentane) were distilled under nitrogen from LiAlH4. All solvents
for vacuum-line manipulations were stored in vacuo over LiAlH4
in resealable flasks. Deuterated solvents were obtained from
Chemotrade Chemiehandelsgesellschaft mbH (all ≥ 99 atom%
D) and were degassed, dried, and stored in vacuo over Na/K
alloy in resealable flasks. NMR spectra were recorded on a JNM-
LA 400 FT-NMR spectrometer. Chemical shifts are referenced
to internal solvent resonances and are reported relative to
tetramethylsilane (1H NMR) and 85% phosphoric acid (31P
NMR), respectively. Elemental analyses were carried out with
an Elementar vario EL. [(PhCH2)4Zr],30 Cp2ZrCl2,31 HN(R-
*CHMePh)(PPh2) (1a) and HN(S-*CHMePh)(PPh2) (1b) were
prepared according to literature procedures.23
7.49 (m, 4H, Ph). 31P{ H} NMR (C6D6, 161.7 MHz, 23.2 C): d
1
−7.0. C41H40NPZr (668.93): calc.: C, 73.61; H, 6.03; N, 2.09%;
found: C, 72.40; H, 6.40; N, 2.13%.
X-Ray crystallographic studies of 2, 4a, 4b and 5
Crystals of 2, 4a and 4b were grown from toluene. Crystals
of 5 were obtained from toluene–n-pentane (1:3). A suitable
crystal was covered in mineral oil (Aldrich) and mounted on a
glass fiber. The crystal was transferred directly to the −70 ◦C
cold stream of an Bruker Smart 1000 CCD diffractometer.
Subsequent computations were carried out on an Intel Pentium
IV PC.
Crystal data for 2. C20H20NOP, M = 321.34, tetragonal,
space group P43 (no. 78), a = 1140.9(2), c = 1327.9(4) pm,
V = 1728.6(6) × 106 pm3, T = 173 K, Z = 4, l(Mo-Ka) =
0.163 mm−1, 21279 reflections measured, 5226 reflections unique
(Rint = 0.0151), observed data [I > 2r(I)] = 5069, Flack
parameter 0.05(4), R1 = 0.0263, wR2 = 0.0742. The structure
was solved and refined using SHELXS-9732 and SHELXL-97.33
=
HN(S-*CHMePh)(P( O)Ph2) (2). 1.652 g (5.42 mmol) of
1b in 5 mL of toluene were treated with 2 ml 30% H2O2-
solution and exposed to air for a few days. Shaking of the
resulted concentrated solution gave a white microcrystalline
precipitate. The suspension was filtered and the resulting residue
suspended in distilled wat◦er, filtered, washed with n-pentane
Crystal data for 4a. C30H29ClNPZr, M = 561.18, mono-
clinic, space group P21 (no. 4), a = 869.73(6), b = 1084.36(6),
c = 1359.07(6) pm, b = 94.583(4)◦, V = 1277.65(13) × 106
pm3, T = 173 K, Z = 2, l(Mo-Ka) = 0.617 mm−1, 9926
reflections measured, 5472 reflections unique (Rint = 0.0263),
observed data [I > 2r(I)] = 5319, Flack parameter −0.03(2),
R1 = 0.0205, wR2 = 0.0526. The structure was solved and refined
using SHELXS-9732 and SHELXL-97.33
1
(10 mL) and dried at 100 C. Yield: 1.026 g (59%). H NMR
(CDCl3, 400 MHz, 25 ◦C): d 1.42 (d, 3H, CH3, 3J(H,H) =
6.8 Hz), 3.43 (br, 1H, NH), 4.34 (br, 1H, CH), 7.1–7.6 (m, 11H,
1
Ph) 7.7–8.0 (m, 4H, Ph). 31P{ H} NMR (CDCl3, 161.7 MHz,
25 ◦C): d 23.2.
LiN(R-*CHMePh)(PPh2)·(3a) and LiN(S-*CHMePh)(PPh2)
(3b). 69 mL (110 mmol) of a 1.6 M solution of n-BuLi in
hexane was added slowly to a stirred solution of 1a,b (3.05 g,
100 mol) in 40 mL of THF at 0 ◦C. A yellow precipitate was
immediately formed. The mixture was then stirred for 1 h at
room temperature, filtered at −78 ◦C and the remaining yellow
residue suspended in 5 mL n-pentane. The suspension was
filtered and the remaining residue was dried in vacuo. Yield 3a:
Crystal data for 4b. C30H29ClNPZr, M = 561.18, mono-
clinic, space group P21 (no. 4), a = 871.2(2), b = 1083.3(2),
c = 1359.3(3) pm, b = 94.471(4)◦, V = 1279.0(4) 106 pm3,
T = 173 K, Z = 2, l(Mo-Ka) = 0.617 mm−1, 15936 reflections
measured, 7480 reflections unique (Rint = 0.0118), observed data
[I > 2r(I)] = 7480, Flack parameter 0.004(15), R1 = 0.0167,
D a l t o n T r a n s . , 2 0 0 5 , 2 1 4 7 – 2 1 5 0
2 1 4 9

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wR2 = 0.0443. The structure was solved and refined using
R. van Asselt, J. M. Ernsting, K. Vrieze, C. J. Elsevier, W. J. J. Smeets,
A. L. Spek and A. P. M. Kentgens, Organometallics, 1993, 12, 1523–
1536.
SHELXS-9732 and SHELXL-97.33
Crystal data for 5. C41H40NPZr, M = 668.93, monoclinic,
a = 879.8(2) pm, b = 997.5(3) pm, c = 1911.0(5) pm, b =
95.067(6)◦, V = 1670.7(7) 106 pm3, T = 173 K, space group
P21 (No. 4), Z = 2, l(Mo–Ka) = 0.407 mm−1, 20675 reflections
measured, 10067 reflections unique (Rint = 0.0328), observed
11 C. M. Ong, P. McKarns and D. W. Stephan, Organometallics, 1999,
18, 4197–4208.
12 M. T. Gamer, S. Dehnen and P. W. Roesky, Organometallics, 2001,
20, 4230–4236.
13 G. Aharonian, K. Feghali, S. Gambarotta and G. P. A. Yap,
Organometallics, 2001, 20, 2616–2622.
data [I > 2r(I)] = 7951, Flack parameter −0.02(3), R1
=
14 M. T. Gamer and P. W. Roesky, Z. Anorg. Allg. Chem., 2001, 627,
0.0400, wR2 = 0.0767. The structure was solved and refined
877–881.
using SHELXS-9732 and SHELXL-97.33
15 Review:R. G. Cavell, R. P. Kamalesh Babu and K. Aparna,
J. Organomet. Chem., 2001, 617–618, 158–169.
16 R. P. Kamalesh Babu, R. McDonald and R. G. Cavell, Chem.
Commun., 2000, 481–482.
17 K. Aparna, R. P. Kamalesh Babu, R. McDonald and R. G. Cavell,
Angew. Chem., 2001, 113, 4535–4537; K. Aparna, R. P. Kamalesh
Babu, R. McDonald and R. G. Cavell, Angew. Chem., Int. Ed., 2001,
40, 4400–4402.
18 (a) A. Kasani, R. P. Kamalesh Babu, R. McDonald and R. G. Cavell,
Organometallics, 1999, 18, 3775–3777; (b) K. Aparna, R. McDonald,
M. Fuerguson and R. G. Cavell, Organometallics, 1999, 18, 4241–
4243.
CCDC reference numbers 265442–265445.
See http://www.rsc.org/suppdata/dt/b5/b503956h/ for cry-
stallographic data in CIF or other electronic format.
Acknowledgements
This work was supported by the Deutsche Forschungsgemein-
schaft and the Fonds der Chemischen Industrie.
19 R. P. Kamalesh Babu, R. McDonald, S. A. Decker, M. Klobukowski
and R. G. Cavell, Organometallics, 1999, 18, 4226–4229.
20 (a) F. T. Edelmann, Top. Curr. Chem., 1996, 179, 113–148; (b) U.
Reissmann, P. Poremba, M. Noltemeyer, H.-G. Schmidt and F. T.
Edelmann, Inorg. Chim. Acta, 2000, 303, 156–162; (c) A. Recknagel,
A. Steiner, M. Noltemeyer, S. Brooker, D. Stalke and F. T. Edelmann,
J. Organomet. Chem., 1991, 414, 327–35; (d) A. Recknagel, M.
Witt and F. T. Edelmann, J. Organomet. Chem., 1989, 371, C40–
C44.
21 (a) S. Agarwal, C. Mast, K. Dehnicke and A. Greiner, Macromol.
Rapid Commun., 2000, 21, 195; (b) P. Ravi, T. Groeb, K. Dehnicke
and A. Greiner, Macromolecules, 2001, 34, 8649.
22 (a) H. Brunner and R. G. Gastinger, J. Organomet. Chem., 1978,
145, 365–373; (b) H. Brunner and G. O. Nelson, J. Organomet.
Chem., 1979, 173, 389–395; (c) E. Frauendorfer and H. Brunner,
J. Organomet. Chem., 1982, 240, 371–379.
References
1 Review: (a) G. J. P. Britovsek, V. C. Gibson and D. F. Wass, Angew.
Chem., 1999, 111, 448–468; G. J. P. Britovsek, V. C. Gibson and D. F.
Wass, Angew. Chem., Int. Ed., 1999, 38, 428–447; (b) R. Kempe,
Angew. Chem., 2000, 112, 478–504; R. Kempe, Angew. Chem., Int.
Ed., 2000, 39, 468–493.
2 D. Fenske, B. Maczek and K. Maczek, Z. Anorg. Allg. Chem., 1997,
623, 1113–1120.
3 O. Ku¨hl, T. Koch, F. B. Somoza, P. C. Junk, E. Hey-Hawkins, D. Plat
and M. S. Eisen, J. Organomet. Chem., 2000, 604, 116–125.
4 O. Ku¨hl, P. C. Junk and E. Hey-Hawkins, Z. Anorg. Allg. Chem.,
2000, 626, 1591–1594.
5 (a) T. G. Wetzel, S. Dehnen and P. W. Roesky, Angew. Chem., 1999,
111, 1155–1158; T. G. Wetzel, S. Dehnen and P. W. Roesky, Angew.
Chem., Int. Ed., 1999, 38, 1086–1088; (b) S. Wingerter, M. Pfeiffer,
F. Baier, T. Stey and D. Stalke, Z. Anorg. Allg. Chem., 2000, 626,
1121–1130.
6 P. W. Roesky, M. T. Gamer, M. Puchner and A. Greiner, Chem.–
Eur. J., 2002, 8, 5265–5271.
7 (a) P. Braunstein, J. Durand, G. Kickelbick, M. Knorr, X. Morise,
R. Pugin, A. Tiripicchio and F. Ugozzoli, Dalton Trans., 1999, 4175–
4186; (b) M. Kno¨rr and C. Strohmann, Organometallics, 1999, 18,
248–257; (c) P. Braunstein, J. Cossy, M. Knorr, C. Strohmann and P.
Vogel, New J. Chem., 1999, 23, 1215–1222.
23 R. P. Kamalesh Babu, S. Krishnamurthy, S. Setharampattu and M.
Nethaji, Tetrahedron: Asymmetry, 1995, 6, 427–438.
24 B. Krzyzanowska and W. J. Stec, Synthesis, 1982, 270–273.
25 N. Dufour, J.-P. Majoral, A.-M. Camiade, R. Choukroun and Y.
Dromzee, Organometallics, 1991, 10, 45–48.
26 M. T. Gamer, M. Rasta¨tter and P. W. Roesky, Z. Anorg. Allg. Chem.,
2002, 628, 2269–2272.
27 J. J. Eisch, F. A. Owuor and P. O. Otieno, Organometallics, 2001, 20,
4132–4134.
8 For reviews, see: (a) K. Dehnicke and F. Weller, Coord. Chem. Rev.,
1997, 158, 103–169; (b) K. Dehnicke, M. Krieger and W. Massa,
Coord. Chem. Rev., 1999, 182, 19–65.
9 P. Imhoff, J. H. Guelpen, K. Vrieze, W. J. J. Smeets, A. L. Spek and
C. J. Elsevier, Inorg. Chim. Acta, 1995, 235, 77–88.
10 (a) M. W. Avis, M. E. van der Boom, C. J. Elsevier, W. J. J. Smeets
and A. L. Spek, J. Organomet. Chem., 1997, 527, 263–276; (b) M. W.
Avis, C. J. Elsevier, J. M. Ernsting, K. Vrieze, N. Veldman, A. L. Spek,
K. V. Katti and C. L. Barnes, Organometallics, 1996, 15, 2376–2392;
(c) M. W. Avis, K. Vrieze, H. Kooijman, N. Veldman, A. L. Spek
and C. J. Elsevier, Inorg. Chem., 1995, 34, 4092–4105; (d) P. Imhoff,
28 E. J. Crust, A. J. Clarke, R. J. Deeth, C. Morton and P. Scott, Dalton
Trans., 2004, 4050–4058.
29 I. J. Munslow, A. R. Wade, R. J. Deeth and P. Scott, Chem. Commun.,
2004, 2596–2597.
30 U. Zucchini, E. Albizzati and U. Giannini, J. Organomet. Chem.,
1971, 26, 357–372.
31 E. Samuel, Bull. Soc. Chim. Fr., 1966, 11, 3548–3564.
32 G. M. Sheldrick, SHELXS-97, Program of Crystal Structure Solu-
tion, University of Go¨ttingen, Germany, 1997.
33 G. M. Sheldrick, SHELXL-97, Program of Crystal Structure Refine-
ment, University of Go¨ttingen, Germany, 1997.
2 1 5 0
D a l t o n T r a n s . , 2 0 0 5 , 2 1 4 7 – 2 1 5 0