Aminotroponiminate alkyl and alkoxide complexes of zinc

Article abstract of DOI:10.1016/j.jorganchem.2004.04.050

Reaction of {(iPr)₂ATI}H ((iPr)₂ ATI=N-isopropyl-2-(isopropylamino)troponiminate) with dimethyl zinc in toluene afforded the methyl complex [{(iPr)₂ATI} Zn-Me]. Subsequent reaction of [{(iPr)₂ATI}Zn-Me] with different alcohols gave the alkoxide complexes [{(iPr)₂ATI} Zn-OR]₂(R = iPr, tBu, Ph). These compounds, which were investigated by single crystal X-ray diffraction, are dimeric in the solid-state. In the solid-state the metal centers are bridged symmetrically by two μ-oxygen atoms, thus a flat Zn-O-Zn′-′ plane is observed. [{(iPr)₂ATI}Zn-OR] ₂ were used as catalysts for the copolymerization experiments of epoxides and CO₂.

Full text of DOI:10.1016/j.jorganchem.2004.04.050

Journal of Organometallic Chemistry 689 (2004) 2720–2725
www.elsevier.com/locate/jorganchem
Aminotroponiminate alkyl and alkoxide complexes of zinc
a
Jost-Steffen Herrmann , Gerrit A. Luinstra , Peter W. Roesky
b
a,
*
a
Institut fu¨r Chemie, Freie Universita¨t Berlin, Fabeckstraße 34-36, 14195 Berlin, Germany
b
BASF Aktiengesellschaft, D-67056 Ludwigshafen, Germany
Received 11 March 2004; accepted 27 April 2004
Available online 7 July 2004
Dedicated to Professor Manfred Meisel on the occasion of his 65th birthday
Abstract
Reaction of {(iPr)2ATI}H ((iPr)2ATI=N-isopropyl-2-(isopropylamino)troponiminate) with dimethyl zinc in toluene afforded the
methyl complex [{(iPr)2ATI}Zn–Me]. Subsequent reaction of [{(iPr)2ATI}Zn–Me] with different alcohols gave the alkoxide com-
plexes [{(iPr)2ATI}Zn–OR]2 (R=iPr, tBu, Ph). These compounds, which were investigated by single crystal X-ray diffraction,
are dimeric in the solid-state. In the solid-state the metal centers are bridged symmetrically by two l-oxygen atoms, thus a flat
Zn–O–Zn0–O0 plane is observed. [{(iPr)2ATI}Zn–OR]2 were used as catalysts for the copolymerization experiments of epoxides
and CO2.
ꢀ 2004 Elsevier B.V. All rights reserved.
Keywords: Aminotroponiminate; Coordination chemistry; Copolymerization of epoxides and CO2; N ligands; Zinc
1. Introduction
[11]. Recently Rieger et al. [12,13] have shown that the
ethylsulfinate ligand is a highly efficient initiating group
for the zinc b-diiminate catalyzed copolymerization re-
action of CO2 and epoxides, whereas Chisholm et al.
[14] reported hydroxyl end groups in polycarbonates
produced by zinc gluterate catalysts. InoueÕs [15] discov-
ery of a heterogeneous ZnEt2/H2O mixture for copolym-
erization of CO2 and propene oxide inspired the
development of a number of additional heterogeneous
systems. We were interested in the chemistry of zinc
complexes with related amindinate ligands. After nu-
merous main group [16,17], d- and f-transition metal
complexes [18–20] with aminotroponiminates were pre-
pared, we now report on these compounds as ancillary
ligands on zinc alkoxides. Aminotroponiminates
({(R)2ATI}ꢀ) (A) are bidentate, monoanionic ligands
containing a 10 p-electron backbone. Due to the pres-
ence of the highly delocalised p-electron system, the
nearly planar {(R)2ATI}ꢀ ligand framework shows little
Recently, there has been a growing interest in zinc
alkoxides and carboxylates since it was shown that these
compounds exhibit high activity for the copolymeriza-
tion of epoxides such as cyclohexene oxide and propene
oxide and CO2 under mild conditions [1–4]. Especially
Coates et al. [5–8] have demonstrated that zinc alkoxides
with bulky b-diiminate ligands in the coordination
sphere exhibit unprecedented rates for the (living) copo-
lymerization of cyclohexene oxide and CO2 to make
polycarbonates, the synthesis of poly(lactic acid) by ster-
eoselective ROP of lactide [9,10], and the ring-opening
polymerization of b-butyrolactone and c-valerolactone
*
Corresponding author. Tel.: +49-30-838-54004; fax: +49-30-838-
52440.
E-mail address: roesky@chemie.fu-berlin.de (P.W. Roesky).
0022-328X/$ - see front matter ꢀ 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2004.04.050

J.-S. Herrmann et al. / Journal of Organometallic Chemistry 689 (2004) 2720–2725
2721
2 ZnR2
- 2 RH
N
N
N
N
Zn
R
Zn
R
1 x
2 x
NH HN
R = Me, Et
N
N
2 ZnMe2
- 4 MeH
N
H2{(i Pr)TP}
N
N
N
N
Zn
Zn
N
N
N
Scheme 1.
reactivity towards most nucleophiles and electrophiles
[21].
N
N
N
N
toluene
- CH4
Zn Me
H
R
N
ZnMe2 +
1
N
R
ROH
- CH4
A
A preliminary report concerned the coordination
chemistry of zinc with the n-propyl bridged bis amino-
troponiminate {(iPr)TP}2ꢀ. It was shown there that
the reactions of H2{(iPr)TP} with dialkyl zinc com-
pounds in toluene lead – in dependence of the stoichiom-
etry – either to bimetallic mono bridged products of the
composition [(RZn)2{(iPr)TP}] (R=Me, Et) or to bime-
tallic double bridged helical products of the composition
[Zn{(iPr)TP}]2 (Scheme 1) [22].
R
N
N
N
O
Zn
Zn
0.5
O
R
N
R = iPr (2), tBu (3), Ph (4)
Scheme 2.
In this paper, the synthesis of N-isopropyl-2-(isopro-
pylamino)troponiminate zinc methyl [{(iPr)2ATI}Zn–
Me] is reported, along with details of further reactions
of this reagent with various alcohols. These reactions
lead to dimeric aminotroponiminate zinc alkoxides
[{(iPr)2ATI}Zn–OR]2. In addition the use of the com-
pounds as catalysts in the copolymerization of epoxides
and CO2 is examined.
2. Results and discussion
The zinc alkyl complex [{(iPr)2ATI}Zn–Me] (1) was
synthesized by reaction of the neutral ligand {(iPr)2
ATI} H [23] with dimethyl zinc in toluene at low tem-
perature (Scheme 2). Compound 1 was obtained as a
yellow crystalline solid with fairly high reactivity to-
wards air and moisture. It was characterized by MS,
1H and 13C NMR spectroscopy. The 1H and
Fig. 1. Perspective ORTEP view of the molecular structure of 2.
Thermal ellipsoids are drawn to encompass 50% probability. Hydro-
gen atoms are omitted for clarity. Selected bond lengths (pm) and
Angles (ꢁ): Zn–O 196.0(2), Zn–O0 198.0(2), Zn–N1 199.8(2), Zn–N2
200.1(2), N1–C1 133.1(3), N2–C2 133.2(3); O–Zn–O0 80.87(7), O–Zn–
N1 129.38(8), O0–Zn–N1 121.27(7), O–Zn–N2 125.62(8), O0–Zn–N2
123.93(8), N1–Zn–N2 81.86(8), Zn–O–Zn0 99.13(7).

2722
J.-S. Herrmann et al. / Journal of Organometallic Chemistry 689 (2004) 2720–2725
1
shifted (d H: 0.00 ppm; 13C{1H} ꢀ9.89 ppm). It is in
the same range as that of the bimetallic complex
[(MeZn)2{(iPr)TP}] (d 1H: ꢀ0.07 ppm; 13C{1H}
ꢀ10.8 ppm (1)) [22]. Compound 1 was also character-
ized by EI mass spectroscopy. In the mass spectrum
the molecular ion as well as its characteristic fragmen-
tation pattern was observed.
In situ preparation of 1 and further reaction with
i-propanol, t-butanol, and phenol, respectively, led to
the dimeric zinc alkoxides [{(iPr)2ATI}Zn–OR]2
(R=iPr (2), tBu (3), Ph (4)) (Scheme 2). The new di-
meric complexes have been characterized by standard
analytical/spectroscopic techniques, and the solid-state
structure was established by single crystal X-ray dif-
fraction (Figs. 1 and 2). The room temperature 1H
and 13C NMR spectra of 2–4 show a symmetrical pat-
tern for the {(iPr)2ATI}ꢀ ligand. Compared to the
Fig. 2. Perspective ORTEP view of the molecular structure of 4.
Thermal ellipsoids are drawn to encompass 50% probability. Selected
bond lengths (pm) and Angles (ꢁ): Zn–O 196.7(3), Zn–O0 202.6(2), Zn–
N1 197.5(3), Zn–N2 197.4(3), N1–C1 133.8(4), N2–C2 133.7(4);
O–Zn–O0 77.93(11), O–Zn–N1 130.26(12), O0–Zn–N1 123.54(12), O–
Zn–N2 129.01(12), O0–Zn–N2 119.17(11), N1–Zn–N2 82.65(12), Zn–
O–Zn0 102.07(11).
1
starting material 1 (d 3.76 ppm), the H NMR signals
of the isopropyl CH of 2–4, which are well-resolved
into a septet, are shifted to lower field (d 3.92 ppm
(2), d 3.98 ppm (3), d 3.89 ppm (4)). The solid-state
structures of 2–4 were investigated by single crystal
X-ray diffraction. A full refinement of the single crys-
tal X-ray structure was possible only for 2 and 4. The
structures revealed that 2–4 adopt dimeric structure in
the solid-state. This is in agreement with the b-diimine
zinc alkoxide complex [(BDI)Zn–OiPr]2 (BDI=N,N0-
bis(2,6-diisopropylphenyl)-(1,3-dimethyl-1,3-propane
diylidene) [9], which also forms a dimer in the solid-
13C NMR spectra point to a symmetric coordination of
the {(iPr)2ATI}ꢀ ligand in solution. The signal of the
isopropyl CH of 1 appears as a well-resolved septet.
The chemical shift (d 3.76 ppm) is in the range of the
free ligand {(iPr)2ATI}H (d 3.60) [23]. In the bridged
zinc complexes [(RZn)2{(iPr)TP}] (R=Me, Et) the iso-
propyl CH signal is also slightly downfield shifted com-
pared to the neutral ligand. In comparison to the
starting material ZnMe2 (d 1H: 0.51; 13C{1H} ꢀ4.2)
[24], the signal of the Zn–CH3 group of 1 is high field
Table 1
Copolymerization results obtained with catalysts 2 and 3a
Entry
Catalyst
Cocatalystb
Conditionsc
Yield of polymer (%)
Yield of polycarbonate by NMR (%)
PO (ml)
CHO (ml)
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
–
2
<5
53d
–
–
–
0.14
0.7
1.8
1
81
–
3
–
4
0.01 eq
0.01 eq
0.01 eq
0.1 eq
0.1 eq
0.1 eq
–
2
–
–
5
0.14
0.7
1.8
1
50
26
29
–
67d
44
5
54
53
48
–
6
7
8
8
0.14
0.7
1.8
1
9
75
16
–
10
11
12
13
14
15
16
17
18
2
–
0.14
0.7
–
1.8
1
–
9
–
0.01 eq
0.01 eq
0.01 eq
0.1 eq
0.1 eq
0.1 eq
2
53
11
29
64
9
17
–
0.14
0.7
1.8
1
67
29
–
8
0.14
0.7
1.8
1
62
20
a
100 mg of catalyst in a 5 ml reactor.
Tetrahexylammonium benzoate.
b
c
Reaction temperature: 80 ꢁC, CO2 pressure 25 bar; reaction time 2 h.
Oil.
d

J.-S. Herrmann et al. / Journal of Organometallic Chemistry 689 (2004) 2720–2725
2723
state. In compounds 2–4 the metal centers are bridged
4. Experimental
symmetrically by two l-oxygen atoms. In the center of
the Zn–O–Zn0–O0 plane, a crystallographic inversion
center is observed. The Zn–Zn0 distance is 299.83(6)
pm in 2 and 310.48(10) pm in 4, and the four-
membered Zn–O–Zn0–O0 ring is planar. The four-
coordinated zinc centers in 2 and 4 exhibit a highly
distorted tetrahedral geometry. The observed Zn–N
bond lengths (Zn–N1 199.8(2) pm, Zn–N2 200.1(2)
pm (2), and Zn–N1 197.5(3) pm, Zn–N2 197.4(3)
pm (4)) are shorter than in [(BDI)Zn–OiPr]2 (Zn–N:
207.4(4) pm and 205.4(4) pm) [9]. The bond lengths
between the zinc and the l-bridging oxygen atoms
are Zn–O 196.0(2) pm and Zn–O0 198.0(2) pm in 2
and Zn–O 196.7(3) pm and Zn–O0 202.6(2) pm in 4.
The corresponding O–Zn–O0 angles are 80.87(7)ꢁ in
2 and 77.93(11)ꢁ in 4.
4.1. General
All manipulations of air-sensitive materials were per-
formed with the rigorous exclusion of oxygen and mois-
ture in flamed Schlenk-type glassware either on a dual
manifold Schlenk line or in an argon-filled M. Braun
glove box. Hydrocarbon solvents (toluene, n-heptane,
and n-pentane) were distilled under nitrogen from
LiAlH4. Deuterated solvents were obtained from Ald-
rich Inc. (all 99 atom % D) and were degassed, dried,
and stored in vacuum over Na/K alloy in resealable
flasks. NMR spectra were recorded on JEOL JNM-
LA 400 FT-NMR spectrometer. Chemical shifts are ref-
erenced to internal solvent resonances and are reported
relative to tetramethylsilane. Mass spectra were record-
ed at 80 eV on Varian MAT 711. Elemental analyses
were carried out with an Elementar vario EL. ZnMe2
was purchased from Aldrich Inc. in a 2M solution in tol-
uene and {(iPr)2ATI}H [23] was prepared according to
the literature procedures.
Copolymerization experiments of epoxides and CO2
were performed by using 2 and 3 as catalysts. As
monomer either propene oxide (PO), cyclohexene
oxide (CHO) or
a mixture of both was used.
Polymerization experiments with 100 mg of catalyst
loading were made in neat epoxide at 25 bar of CO2
pressure at 80 ꢁC reaction temperature. Quenching
of the polymerization experiments after 4 h and
workup in methanol gave only low yields of the ex-
pected polycarbonate. In some cases the polymers do
not solely consist of polycarbonate. Using
tetrahexylammonium benzoate as cocatalyst did not
significantly improve the catalytic activity. The
detailed results of the catalytic studies are listed in
Table 1.
4.2. [{(iPr)2ATI}Zn–Me] (1)
0.64 ml (1.28 mmol, 1.05 eq) of a 2.0 M ZnMe2 solution
in toluene was diluted in 25 ml of toluene. At ꢀ78 ꢁC a so-
lution of {(iPr)2ATI}H (250 mg, 1.22 mmol) in toluene
(25 ml) was added. The reaction mixture slowly was
warmed up to room temperature and gas evolution was
observed. After the gas evolution had stopped (about 3
h) the solution was filtered off, and the solvent was evap-
orated in vacuum. The resulting yellow solid was washed
with n-pentane (3·10 ml) and dried in vacuum. Yield: 287
mg (83%). 1H NMR (C6D6, 400 MHz, 25 ꢁC): d=0.00 (s,
3. Conclusions
3
3H, –ZnCH3), 1.14 (d, 12H, –NCH(CH3)2, J(H,H)=
3
6.11 Hz), 3.76 (sept., 2H, –NCH(CH3)2, J(H,H)=6.18
Reaction of {(iPr)2ATI}H with dimethyl zinc in tolu-
ene afforded the methyl complex [{(iPr)2ATI}Zn–Me].
Subsequent reaction of [{(iPr)2ATI}Zn–Me] with differ-
ent alcohols gave the alkoxide complexes [{(iPr)2ATI}-
Zn–OR]2 (R=iPr, tBu, Ph). These compounds are
dimeric in the solid-state. The catalytic activity for the
copolymerization of CO2 and epoxides of these com-
pounds is much lower than the those observed for the
corresponding b-diimine zinc alkoxide complexes
[(BDI)Zn–OR]2. It was shown earlier that the catalytic
activity of the zinc alkoxide complexes strongly depends
on the steric and electronic properties of the ligand,
which influences the monomer dimer equilibrium of
the bimetallic zinc complexes and also influences the ap-
proach of the organic monomer to the active site [6]. Ap-
parently, the dimer zinc complexes with the (iPr)2ATI
ligand do not render a favorable combination for epox-
ide-CO2 copolymerization activity. This may be either
steric – (iPr)2ATI is less bulky than BDI – or electronic
– (iPr)2ATI is less donating – in origin.
3
Hz), 6.35 (dd, 1H, H5, J(H,H)=9.39 Hz), 6.57 (d, 2H,
H3,7
,
3J(H,H)=11.23 Hz), 6.95 (dd, 2H, H4,6
,
J(H,H)=9.39 Hz, 10.23 Hz). 13C{1H} NMR (C6D6,
100.4 MHz, 25 ꢁC): d=ꢀ9.9 (–ZnCH3), 24.5 (–NCH
(CH3)2), 48.3 (–NCH(CH3)2), 111.6 (C5), 117.7 (C3,7),
134.5 (C4,6), 160.2 (C1,2). EI–MS m/z (%): ꢀ282 (33)
[M]+, 267 (51) [MꢀCH3]+, 204 (24) [MꢀZnCH3]+.
4.3. [{(iPr)2ATI}Zn–OiPr]2 (2)
3.85 ml (7.71 mmol, 1.05 eq) of a 2.0 M ZnMe2
solution in toluene was diluted in 25 ml of toluene. At
ꢀ78 ꢁC a solution of {(iPr)2ATI}H (1.5 g, 7.34 mmol)
in toluene (30 ml) was added. The reaction mixture
slowly was warmed up to room temperature and gas ev-
olution was observed. After the gas evolution had
stopped (about 3 h) 0.62 ml (8.07 mmol, 1.1 eq) of i-pro-
panol was added, immediately followed by gas evolu-
tion. Then the solvent was evaporated in vacuum. The

2724
J.-S. Herrmann et al. / Journal of Organometallic Chemistry 689 (2004) 2720–2725
resulting yellow solid was washed with n-pentane (3·10
ml) and dried in vacuum. Finally, the product was
crystallized from toluene/n-heptane (1:2). Yield: 2.03 g
d=24.2 (–NCH(CH3)2), 48.7 (–NCH(CH3)2), 112.3
(C5), 117.4 (C3,7), 118.6 (Ph), 118.7 (Ph), 129.9 (Ph),
135.3 (C4,6), 159.5 (C1,2), 160.7 (Ph). EI-MS m/z (%):
ꢀ360 (12) [M/2]+, 345 (16) [M/2ꢀCH3]+, 267 (7)
[M/2ꢀOC6H5]+, 251 (10) [M/2ꢀOC6H5,ꢀCH3]+, 204
(14) [M/2ꢀZnOC6H5]+, 94 (100) [C6H6O]. –C38H48N4-
O2Zn2 (723.58): Calc. C, 63.08, H, 6.69, N, 7.74. Found:
C, 62.00, H, 6.24, N, 7.53%.
1
(84%). H NMR (C6D6, 400 MHz, 25 ꢁC): d=1.03 (d,
12H, –OCH(CH3)2, 3J(H,H)=5.99 Hz), 1.39 (d,
24H, –NCH(CH3)2, 3J(H,H)=6.31 Hz), 3.92 (sept.,
3
4H, –NCH(CH3)2, J(H,H)=6.42 Hz), 4.21 (sept., 2H,
–OCH(CH3)2, 3J(H,H)=5.97 Hz), 6.27 (dd, 2H, H5,
J(H,H)=9.15 Hz, 8.75 Hz), 6.54 (d, 4H, H3,7
,
3J(H,H)=11.31 Hz), 6.96 (dd, 4H, H4,6, J(H,H)=9.27
Hz, 11.95 Hz). 13C{1H} NMR (C6D6, 100.4 MHz, 25
ꢁC): d=24.6 (–NCH(CH3)2), 28.5 (–OCH(CH3)2), 48.9
(–NCH(CH3)2), 66.4 (–OCH(CH3)2), 111.4 (C5), 115.9
(C3,7), 134.9 (C4,6), 159.7 (C1,2). EI-MS m/z (%): ꢀ326
(100) [M/2]+, 268 (52) [M/2ꢀOC3H7]+, 204 (34) [M/
2ꢀZnOC3H7]+. –C32H52N4O2Zn2 (655.55): Calc. C,
58.63, H, 8.00, N, 8.55. Found: C, 58.38, H, 7.76, N,
8.36%.
5. Copolymerization experiments
Polymerization reactions were carried out in 5 ml
autoclaves equipped with a magnetic stirrer, oil bath
heating and a check valve. About 100 mg of catalyst
were transferred into the autoclave. Subsequently the
monomer and the solvent were added. The reactor
was pressurized to 25 bar and heated to 80 ꢁC. After
stirring for 4 h the reactor was cooled down, slowly de-
pressurized, and opened. The reaction mixture was
slowly precipitated in methanol, stirred, isolated, and
dried.
4.4. [{(iPr)2ATI}Zn–O tBu]2 (3)
Compound 3 was prepared in an analogous way to 2
by using 3.85 ml (7.71 mmol, 1.05 eq) of a 2.0 M ZnMe2
solution in toluene, 1.5 g (7.34 mmol) of {(iPr)2ATI}H,
and 0.77 ml (8.07 mmol, 1.1 eq) of t-butanol. X-ray
quality crystals could be grown from n-heptane. Yield:
2.04 g (81%). 1H NMR (C6D6, 400 MHz, 25 ꢁC):
6. X-ray crystallographic studies of 2, 3 and 4
Crystals of 2 and 4 were grown from a hot toluene/n-
heptane (1:2) solution. Crystals of compound 3 were
obtained from hot n-heptane. A suitable crystal was cov-
ered in mineral oil (Aldrich) and mounted on a glass fi-
ber. The crystal was transferred directly to the
ꢀ100 ꢁC cold stream of a Bruker CCD SMART 1000
diffractometer. Subsequent computations were carried
out on an Intel Pentium III Personal Computer.
d=1.24 (s, 18H, –OC(CH3)3), 1.46 (d, 24H,
–
NCH(CH3)2, 3J(H,H)=6.43 Hz), 3.98 (sept., 4H, –
NCH(CH3)2, 3J(H,H)=6.44 Hz), 6.26 (dd, 2H, H5,
J(H,H)=9.11 Hz, 8.79 Hz), 6.60 (d, 4H, H3,7
,
3J(H,H)=11.47 Hz), 6.94 (dd, 4H, H4,6, J(H,H)=9.39
Hz, 11.07 Hz). 13C{1H}NMR (C6D6, 100.4 MHz, 25
ꢁC): d=24.1 (–NCH(CH3)2), 34.6 (–OC(CH3)3), 49.1
(–NCH(CH3)2), 71.1 (–OC(CH3)3), 112.8 (C5), 116.0
(C3,7), 134.5 (C4,6), 160.4 (C1,2). EI–MS m/z (%): ꢀ340
(25) [M/2]+, 268 (15) [M/2ꢀOC4H9]+, 205 (27)
[M/2ꢀZnOC4H9]+. –C34H56N4O2Zn2 (683.60): Calc.
C, 59.74, H, 8.26, N, 8.20. Found: C, 59.37, H, 8.03,
N, 7.85%.
2: Bruker CCD SMART 1000 diffractometer (Mo Ka
radiation); T=173(2) K; data collection and refinement:
SHELXS-97 [25], SHELXL-97 [26]; monoclinic, space
group P21/c (No. 14); lattice constants a=908.4(2),
b=1041.2(12), c=1731.2(3) pm, b=96.628(4)ꢁ, V=
1626.4(5) 106 pm3, Z=2; l(Mo Ka)=1.508 mmꢀ1
;
h
max. =30.00; 4732 (Rint =0.0308) independent reflections
4.5. [{(iPr)2 ATI}Zn–OPh]2 (4)
measured, of which 3451 were considered observed with
I>2r(I); max. residual electron density 2.353 and
ꢀ1.724 e/Aꢀ3; 187 parameters (all non hydrogen atoms
were calculated anisotropically; the positions of the H
atoms were calculated for idealized positions) R1 =
0.0380; wR2 =0.1014.
3: Bruker CCD SMART 1000 diffractometer (Mo Ka
radiation); T=173(2) K; data collection and refinement:
SHELXS-97 [25], SHELXL-97 [26]; triclinic, space group
Compound 3 was prepared in an analogous way to 2
by using 0.64 ml (1.28 mmol, 1.05 eq) of a 2.0 M ZnMe2
solution in toluene, 250 mg (1.22 mmol) of {(iPr)2ATI}H,
and 0.76 ml ((1.28 mmol, 1.05 eq) of phenol. The final
product was crystallized from toluene/n-heptane (1:2).
1
Yield 355 mg (80%). H NMR (C6D6, 400 MHz, 25
ꢁC): d=1.28 (d, 24H, –NCH(CH3)2, 3J(H,H)=6.47
Hz), 3.89 (sept., 4H, –NCH(CH3)2, J(H,H)=6.93 Hz),
3
ꢀ
P1 (No. 2); lattice constants a=937.8(3), b=955.9(3),
6.35 (dd, 2H, H5, J(H,H)=9.27 Hz, 8.43 Hz), 6.61 (m,
2H, p-C6H5), 6.65 (d, 4H, H3,7,
3J(H,H)=10.99 Hz),
6.70 (d, 4H, o-C6H5, J(H,H)=8,39 Hz), 6.90 (m, 4H,
m-C6H5), 6.98 (dd, 4H, H4,6, J(H,H)=10.95 Hz, 9.27
Hz). 13C{1H} NMR (C6D6, 100.4 MHz, 25 ꢁC):
c=1964.0(6) pm, a=92.881(5)ꢁ, b=103.203(5)ꢁ, c=
90.621(6)ꢁ, V=1711.6(9) 106 pm3, Z=2; hmax. =30.00;
9361 (Rint =0.0456) independent reflections measured,
of which 6311 were considered observed with I>2r(I).
The structure could not be completely refined.
3

J.-S. Herrmann et al. / Journal of Organometallic Chemistry 689 (2004) 2720–2725
2725
[2] M.S. Super, E. Berluche, C. Costello, E.J. Beckman, Macromol-
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4: Bruker CCD SMART 1000 diffractometer (Mo Ka
radiation); T=173(2) K; data collection and refinement:
SHELXS-97 [25], SHELXL-97 [26]; triclinic, space group
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Chem. 37 (1999) 1863–1876.
ꢀ
P1 (No. 2); lattice constants a=948.2(3), b=975.5(3),
c=1077.4(3) pm, a=113.277(5)ꢁ, b=108.043(5)ꢁ, c=
[5] M. Cheng, E.B. Lobkovsky, G.W. Coates, J. Am. Chem. Soc. 120
(1998) 11018–11019.
90.178(6)ꢁ, V=861.4(4) 106 pm3, Z=1; l(Mo Ka) =
1.431 mmꢀ1
;
hmax. =30.00; 4950 (Rint =0.0530)
[6] M. Cheng, D.R. Moore, J.J. Reczek, B.M. Chamberlain, E.B.
Lobkovsky, G.W. Coates, J. Am. Chem. Soc. 123(2001)8738–8749.
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Chem. 114 (2002) 2711–2714;
independent reflections measured, of which 3701 were
considered observed with I>2r(I); max. residual elec-
tron density 2.403 and ꢀ1.875 e/Aꢀ3; 212 parameters
(all non hydrogen atoms were calculated anisotropically;
the positions of the H atoms were calculated for ideal-
ized positions) R1 =0.0664; wR2 =0.1776.
Angew. Chem. Int. Ed. 41 (2002) 2599–2602.
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3238.
7. Supplementary material
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Chem. Soc. 124 (2002) 3473–3477.
Crystallographic data (excluding structure factors)
for the structures reported in this paper have been de-
posited with the Cambridge Crystallographic Data Cen-
tre as a Supplementary Publication Nos. CCDC-233551
and 233552. Copies of the data can be obtained free of
charge on application to CCDC, 12 Union Road, Cam-
bridge CB21EZ, UK (fax: +(44)1223-336-033; email: de-
posit@ccdc.cam.ac.uk).
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¨
Acknowledgement
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This work was supported by the Deutsche Fors-
chungsgemeinschaft (Graduiertenkolleg: Synthetische,
mechanistische und reaktionstechnische Aspekte von
Metallkatalysatoren), the Fonds der Chemischen In-
dustrie and BASF Aktiengesellschaft.
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