Cobalt and nickel complexes bearing 2,6-bis (imino) phenoxy ligands: Syntheses, structures and oligomerization studies

Article abstract of DOI:10.1016/S0022-328X(02)01149-X

A series of new cobalt and nickel complexes LMX₂ (M = Co, X = Cl; M = Ni, X = Br) bearing 2, 6-bis(imino)phenoxy ligands were synthesized. The solid-state structures of 1 and 4 have been determined by single-crystal X-ray diffraction study. Treatment of the complexes LMX₂ with methylalumninoxane (MAO) leads toa ctive catalysis for oligomerization of ethylene with catalysis activities in the range of 1.2 × 10⁵-2.1 × 10⁵ g mol^-1 h^-1 atm ^-1 for Ni complexes, and ～ 10³ g mol^-1 h^-1 atm^-1 for Co complexes. The oligomers were olefins from C₄ to C₁₆.

Full text of DOI:10.1016/S0022-328X(02)01149-X

Journal of Organometallic Chemistry 650 (2002) 59–64
www.elsevier.com/locate/jorganchem
Cobalt and nickel complexes bearing 2,6-bis (imino) phenoxy
ligands: syntheses, structures and oligomerization studies
Leyong Wang a, Wen-Hua Sun a,*, Lingqin Han a,1, Zilong Li a, Youliang Hu a,
Cheng He b, Chunhua Yan b
a State Key Laboratory of Engineering Plastics and The Center for Molecular Sciences, Institute of Chemistry,
The Chinese Academy of Sciences, Beijing 100080, People’s Republic of China
b State Key Laboratory of Rare Earth Materials Chemistry and Applications,
Peking Uni6ersity-Nonius B.V. Demo Laboratory for X-Ray Diffraction, Peking Uni6ersity, Beijing 100871, People’s Republic of China
Received 29 October 2001; received in revised form 4 December 2001; accepted 20 December 2001
Abstract
A series of new cobalt and nickel complexes LMX2 (M=Co, X=Cl; M=Ni, X=Br) bearing 2, 6-bis(imino)phenoxy ligands
were synthesized. The solid-state structures of 1 and 4 have been determined by single-crystal X-ray diffraction study. Treatment
of the complexes LMX2 with methylaluminoxane (MAO) leads to active catalysts for oligomerization of ethylene with catalytic
activities in the range of 1.2×105–2.1×105 g mol−1 h−1 atm−1 for Ni complexes, and ꢀ103 g mol−1 h−1 atm−1 for Co
complexes. The oligomers were olefins from C4 to C16. © 2002 Published by Elsevier Science B.V.
Keywords: Cobalt; Nickel; Ethylene oligomerization; Crystal structures
1. Introduction
new neutral Ni(II) salicylaldimiminato complexes as
catalysts for the polymerization of ethylene to obtain
high molecular weight polyolefins under moderate con-
ditions. Modifications of their substituents of imino
groups result in dramatic changes to the productivity of
the catalyst and physical properties of the resultant
polyolefin. For instance, by reducing the steric bulk of
the bisiminopyridine ligands, the resultant iron catalysts
oligomerized ethylene to linear olefins with remarkably
high activity and selectivity [11]. In our current project,
we focus on exploring the effect of changing the central
pyridinyl moiety to phenol. The 2,6-bis(imino)phenoxy
ligands were designed to coordinate with Co(II) and
Ni(II), and the additional imino group could be varied
in order to adapt the activities of the catalysts. The
corresponding complexes were recognized as precursors
for ethylene oligomerization using the co-catalyst
methylaluminoxane(MAO). Herein, we report the syn-
theses and the full characterization of Co(II) and Ni(II)
complexes bearing 2,6-bis(imino)phenoxy ligands, as
well as their properties for the oligomerization of ethyl-
ene with MAO as co-catalyst.
Olefin polymerization and oligomerization promoted
by late transition metal complexes have drawn much
attention in both academic research and industrial ap-
plication [1,2]. Recent progress was made by employing
cationic Ni(II) bis(imine) complexes as effective cata-
lysts for ethylene oligomerization or polymerization
[3–5]. These catalyst systems also incorporate
monomers such as methyl acrylate with ethylene or
propylene resulting in copolymers with considerable
productivities [6,7]. The groups of Brookhart [5,6], Ben-
nett [8] and Gibbson [9] have made great contributions
in designing highly active ethylene polymerization cata-
lysts based on iron(II) and cobalt(II) bearing 2,6-
(imino)pyridyl ligands. Moreover, Grubbs [10] reported
* Corresponding author.
E-mail address: whsun@infoc3.icas.ac.cn (W.-H. Sun).
1 Present address: College of Chemistry and Environmental Sci-
ence, Hebei University, Baoding 071002, People’s Republic of China.
0022-328X/02/$ - see front matter © 2002 Published by Elsevier Science B.V.
PII: S0022-328X(02)01149-X

60
L. Wang et al. / Journal of Organometallic Chemistry 650 (2002) 59–64
Scheme 1.
2. Result and discussion
cisoid conformation in the Co complex 4 (Fig. 2). There
are strong OꢀHꢀN interactions between hydroxy group
[O(1)] and imino nitrogen [N(2)], with the HꢀN distance
2.1. Synthesis and characterization
,
1.720 A and the OꢀHꢀN angle 156.9°. Another conju-
gated imino group is flexible around the C(14)ꢀC(13).
The selected bond lengths and angles for ligand 1 were
shown in Table 1.
The 2,6-bis(imino)phenoxy ligands 1–3 were pre-
pared as yellow solids in good yields by the condensa-
tion of two equivalents of the appropriate aniline with
one equivalent of 2-hydroxy-5-tert-butylisophthalde-
hyde (Scheme 1). Compounds 1–3 were characterized
by microanalysis, proton NMR and mass spectrometry.
Ligand 1 was finally confirmed by single-crystal X-ray
diffraction (Fig. 1).
The complexes 4–6 were synthesized in reasonable
yields by treating CoCl2·6H2O with the corresponding
2,6-bis(inimo)phenoxy ligands in ethanol at elevated
temperature, while the nickel(II) dibromide complexes
7–9 were prepared by reaction of a slight excess of the
corresponding diimino ligand with (1,2-dimethoxy-
ethane)nickel(II) bromide in dichloromethane (Scheme
1). Complexes 4–9 are stable solids and insoluble in
saturated hydrocarbons, while they are soluble in polar
organic solvents, including CH2Cl2, CHCl3, acetonitrile,
etc. The structure of all the complexes 4–9 were confi-
rmed with elemental analyses, IR and FABMS spec-
troscopy. In the FABMS spectra of complexes 4 and
6–9, the ion peaks of complex were not found, only
fairly intense peaks from the fragments due to elimina-
tion of one or two halide and CoCl2(NiBr2). Crystals of
complex 4 suitable for X-ray structural determination
were grown from its ethanol solution. The molecular
structure complex 4 is shown in Fig. 2.
The X-ray analysis of complex 4 shows that this
molecule possesses a cisoid configuration between
imino groups, and the N(1)ꢀC(13)ꢀC(14)ꢀC(19)ꢀ
C(18)ꢀC(24)ꢀN(2) component is co-planar within
,
0.0367 A. The N(1)ꢀC(13)ꢀC(14)ꢀC(19)ꢀO(1)ꢀCo(1)
forms a planar, six-membered chelate ring. The geome-
try around the cobalt atom is a distorted tetrahedron
with cis angles in the range of 92.79–117.55°.
The structure of ligand 1 (Fig. 1) shows that this
molecule possesses a transoid configuration between the
imino groups, a geometry that is different from the
Fig. 1. Molecular structure of ligand 1, showing 30% probability
displacement ellipsoids. Hydrogen atoms are omitted for clarity.

L. Wang et al. / Journal of Organometallic Chemistry 650 (2002) 59–64
61
2.2. Oligomerization of ethylene
Upon treatment with methylaluminoxane(MAO), all
of the complexes 4–9 are active for ethylene oligomer-
ization. Table 3 lists their activity and molecular weight
distribution of the oligomers produced by nickel and
cobalt catalysts. The nature of the metal center has a
major influence on catalytic activities. In general, Ni
catalysts are more active than their corresponding
Co(II) analogues under our conditions. The most active
Ni(II) catalyst is complex 9 (2.1×105 g mol−1 h−1
atm−1), while the Co(II) complexes are less active than
103 g mol−1 h−1 atm−1 for oligomerization.
The metal core of complexes also influence the
molecular weight distribution of oligomers. Cobalt cat-
alysts 4, 5 and 6 yield butylene, while Ni complexes 7,
8 and 9 gave higher olefins such as 1-hexene and
1-octene along with 1-butylene. Stereochemistry of the
ligands affected their catalytic activities. Ni-based cata-
lysts 7–9 revealed that a reduction of steric bulk at the
ortho-aryl position resulted in the increase of their
activities. The complex 7 contains isopropyl groups in
the ortho positions of the aryl rings and display an
Fig. 2. Molecular structure of complex 4, showing 30% probability
displacement ellipsoids. Hydrogen atoms are omitted for clarity.
Table 1
,
Selected bond lengths (A) and angles (°) for ligand 1
Bond lengths
O(1)ꢀC(19)
N(1)ꢀC(1)
N(2)ꢀC(25)
C(18)ꢀC(24)
1.3477(18)
1.429(2)
1.435(2)
1.457(2)
N(1)ꢀC(13)
N(2)ꢀC(24)
C(13)ꢀC(14)
1.266(2)
1.269(2)
1.470(2)
activity of 1.2×105 g mol−1 atm−1
mately complex 8 with dimethyl on the aryl ring with
an activity of 1.9×105 g mol−1 atm−1 −1. Methyl-
h
−1, approxi-
h
Bond angles
substitution on the para-position of aryl (Complex 9)
resulted an slight increase of catalytic activity.
C(13)ꢀN(1)ꢀC(1) 117.31(14)
N(1)ꢀC(13)ꢀC(14) 123.00(15)
O(1)ꢀC(19)ꢀC(18) 121.67(14)
C(24)ꢀN(2)ꢀC(25) 120.16(14)
O(1)ꢀC(19)ꢀC(14) 119.03(13)
N(2)ꢀC(24)ꢀC(18) 122.66(14)
3. Experimental
Table 2
All manipulations were carried out under an atmo-
sphere of nitrogen using standard Schlenk and cannula
techniques. Solvents were refluxed over an appropriate
drying agent and distilled under nitrogen prior to use.
Using HP-MOD 1106 microanalyzer performed ele-
mental analyses. NMR spectra were recorded on a
Bruker spectrometer DMX-300, with TMS as the inter-
nal standard. IR spectra were obtained as KBr pellets
on a Perkin–Elmer FTIR 2000 spectrometer. Mass
spectra were measured on a Kratos AEI MS-50 instru-
ment using either fast atom bombardment (FAB) or
electron impact (EI). Melting points (m.p.) were deter-
mined with a digital electrothermal apparatus without
further correction. Distribution of oligomers obtained
was measured on a HP5890 Series II gas chro-
matograph spectrometer.
,
Selected bond lengths (A) and angles (°) for complex 4
Bond lengths
Cl(1)ꢀCo(1)
Co(1)ꢀO(1)
N(1)ꢀC(13)
N(2)ꢀC(24)
C(18)ꢀC(24)
N(2)ꢀC(25)
2.2263(17) Cl(2)ꢀCo(1)
2.2121(15)
2.023(3)
1.443(4)
1.447(4)
1.299(4)
1.951(2)
1.277(4)
1.295(5)
1.427(5)
1.445(5)
Co(1)ꢀN(1)
N(1)ꢀC(1)
C(13)ꢀC(14)
O(1)ꢀC(19)
Bond angles
O(1)ꢀCo(1)ꢀN(1)
N(1)ꢀCo(1)ꢀCl(2)
N(1)ꢀCo(1)ꢀCl(1)
C(19)ꢀO(1)ꢀCo(1) 127.1(2)
C(13)ꢀN(1)ꢀCo(1) 122.4(2)
C(18)ꢀC(24)ꢀN(2) 122.7(3)
O(1)ꢀC(19)ꢀC(14) 124.0(3)
92.79(10) O(1)ꢀCo(1)ꢀCl(2)
117.59(10) O(1)ꢀCo(1)ꢀCl(1)
113.47(10) Cl(2)ꢀCo(1)ꢀCl(1) 110.56(6)
111.20(11)
109.85(11)
C(13)ꢀN(1)ꢀC(1)
C(1)ꢀN(1)ꢀCo(1)
118.0(3)
119.60(19)
C(24)ꢀN(2)ꢀC(25) 126.3(3)
O(1)ꢀC(19)ꢀC(18) 119.4(3)
Compound 2-hydroxy-5-tert-butylisophthaldehyde
was prepared according to an established procedure
[12], while MAO (1.4 mol l−1) solution in toluene was
purchased from Albemarle Corp (USA); (DME)NiBr2
and all of the anilines were purchased from Aldrich
Chemical Co or Acros Chemical Co. All these were
used commercially without further purification unless
stated otherwise.
The 2,6-diisopropylphenyl substituted aryl ring
(C(1)ꢀC(2)ꢀC(3)ꢀC(4)ꢀC(5)ꢀC(6)) is oriented approxi-
mately orthogonally to the basal coordination plane,
with a approximately 93.6° twist about the N(1)ꢀC(1)
bond. Table 2 listed the selected bond lengths and
angles for complex 4.

62
L. Wang et al. / Journal of Organometallic Chemistry 650 (2002) 59–64
3.1. Preparations of 2,6-bis(imino)phenoxy ligands
3.1.3. 2,6-Diformyl-4-tetra-butyl-phenoxy(2,4,6-
trimethylanil) (3)
By using the same procedure for synthesis of 1, the
ligand 3 was obtained by the reaction of 2-hydroxy-5-
tert-butyl-isophthaldehyde with 2, 4, 6-dimethylaniline
as a yellow power in 89% yield; m.p. 106.5–107 °C. IR
(KBr): 3432 (br), 2964, 2914 (m), 1630 (vs), 1592 (s),
1479 (s), 1373, 1206, 1146,1005, 856 (s), 819, 758 (s)
3.1.1. 2,6-Diformyl-4-tetra-butyl-phenoxy(2,6-diiso-
propylanil) (1)
To a solution of 2-hydroxy-5-tert-butyl-isophthalde-
hyde (1.76 g, 6 mmol) with a few drops of glacial acetic
acid in anhydrous ethanol (25 ml) under N2 at 50 °C
was added a solution of 2,6-diisopropylaniline (2.16 g,
13.2 mmol) in anhydrous ethanol (25 ml) over a period
of 30 min with stirring. Then the mixture was refluxed
for additional 4 h. Upon cooling to room temperature,
the volatiles were removed under vacuum, and the
residue was recrystallized from ethanol at −20 °C to
give the yellow crystals 2.8 g in 70% yield: m.p. 192–
193 °C. IR (KBr): 3414 (m), 3063 (m), 2963, 2869 (s),
1629, 1586 (vs), 1540 (s), 1460 (s), 1360, 1313, 1282,
1
cm−1; H-NMR (CDCl3): d1.45 (9H, s), 2.22 (12H, s),
2.34 (6H, s), 6.95 (4H, s), 8.63 (2H, s); EIMS (m/z): 440
(M+, 12.4%), 307 (M+ꢀNAr%19.0%), 306 ((M+
ꢀNAr%ꢀH, 89.8%), 305 (M+ꢀNAr%ꢀ2H, 100%), 304
(10.4%), 220 (10.0%), 135 (9.6%); Anal. Calc. for
C30H36N2O: C, 81.78; H, 8.24; N, 6.36. Found: C,
81.49%; H, 8.43; N, 6.74%.
3.2. Complexation with CoCl2
1
1227, 1179 (s), 819, 758 (s) cm−1; H-NMR (CDCl3): l
1.27 (24H, d, J=6.8Hz), 1.49 (9H, s), 3.04–3.14 (4H,
m), 7.24 (6H, m), 7.5 (1H, br), 8.37–8.80 (3H, br);
EIMS (m/z): 524 (M+, 7.8%), 509 (M+ꢀCH3, 5.1%),
349 (M+ꢀNAr%, 23.6%), 348 (M+ꢀNAr%ꢀH, 100%), 319
(M+ꢀCH3ꢀNAr%, 5.5%); Anal. Calc. for C36H48N2O: C,
82.39; H, 9.22; N, 5.34. Found: C, 82.10; H, 9.29; N,
5.12%.
3.2.1. [2,6-Diformyl-4-tetra-butyl-phenoxy(2,6-
diisopropylanil)]·CoCl2 (4)
To a solution of Ligand 1 (104 mg, 0.2 mmol) in
anhydrous ethanol (5 ml) under N2 atmosphere at
50 °C was added a solution of CoCl2·6H2O (47.6 mg,
0.2 mmol) in anhydrous ethanol (5 ml). After stirring at
50 °C for 2 h, the solution was cooled to room temper-
ature. The solvent volume was concentrated to 1ml,
and diethyl ether (5 ml) was added to precipitate the
product as a green power. Filtration, washing with
diethyl ether and drying afford of complex 4 as a green
power in 76% yield. The product was recrystallized
from the solution of ethanol and diethyl ether: m.p.\
300 °C. IR (KBr): 3427 (br, s), 2964 (s), 1638 (vs), 1591
(s), 1537 (s), 1463(m), 1388, 1363, 1328, 1289, 1225,
1127 (m), 1059 (m) cm−1; FABMS (m/z): 618 (M+
ꢀCl), 582 (M+ꢀ2Cl), 525 (M+ꢀCoCl2); Anal. Calc. for:
C36H48N2OCoCl2·2H2O: C, 62.61; H, 7.59; N, 4.06.
Found: C, 62.37; H, 7.19; N, 3.80%.
3.1.2. 2,6-Diformyl-4-tetra-butyl-phenoxy-
(2,6-dimethylanil) (2)
By using the procedure described above for synthesis
of 1, the ligand 2 was obtained by the reaction of
2-hydroxy-5-tert-butyl-isophthaldehyde with 2, 6-
dimethylaniline as a yellow power in 79% yield. M.p:
162–163 °C. IR (KBr): 3368 (br), 2962 (s), 1630, 1588
(s), 1469 (s), 1369 (s), 1310, 1284, 1263, 1232, 1190 (m),
1
1091, 1034, 1006 (m), 858, 765 (m) cm−1; H-NMR
(CDCl3): l 1.44 (9H, s), 2.24 (12H, s), 6.95–7.14 (6H,
m), 7.30–8.60 (4H, br); EIMS (m/z): 412 (M+, 6.6%),
411 (4.4%), 292 (M+ꢀNAr%, 100%), 291 (M+ꢀNAr%ꢀH,
85.4%), 290 (8.3%), 277 (M+ꢀCH3ꢀNAr%, 6.6%), 206
(5.1%), 132 (8.2%), 120 (6.9%), 105 (10.1%); Anal. Calc.
for C28H32N2O: C, 81.51; H, 7.82; N, 6.79. Found: C,
81.22; H, 8.21; N, 6.34%.
3.2.2. [2,6-Diformyl-4-tetra-butyl-phenoxy(2, 4,
6-dimethylanil)]·CoCl2 (5)
Using the procedure described in Section 3.2.1, the
reaction of ligand 2 and CoCl2·6H2O gave complex 5 in
Table 3
Activity and distribution for the oligomerization
Catalyst
Complex
MAO (mmol)
Activitya
Distribution of the oligomerization (%)
(mmol)
C4
C6
C8
C10
C12
1.9
C14
1.4
C16
1.0
4
5
6
7
8
9
10
10
10
5
5
5
14
14
14
7
7
7
ꢀ103
100
100
100
ꢀ103
ꢀ103
1.2×105
1.9×105
2.1×105
49.5
77
69
28.2
23
31
14.6
3.4
Toluene solvent, 1 atm of ethylene, reaction time 0.5 h.
a g mol−1 h−1 atm−1
.

L. Wang et al. / Journal of Organometallic Chemistry 650 (2002) 59–64
63
75% yield as a green powder: m.p.\300 °C. IR (KBr):
1143(w), 1064, 1024(s), 853(s) cm−1; FABMS (m/z):
579 (M+ꢀBr), 498 (M+ꢀ2Br), 441 (M+ꢀNiBr2); Anal.
Calc. for C30H36N2ONiBr2·H2O: C, 53.21; H, 5.66; N,
4.14. Found: C, 53.58; H, 5.29; N, 4.48%.
3434 (m), 2963 (s), 1638 (s), 1620 (s), 1539 (s), 1471(m),
1397, 1381, 1363, 1327, 1290 (w), 1236, 1184 (m) cm−1
;
FABMS (m/z): 541 (M+), 506 (M+ꢀCl), 470 (M+
ꢀ2Cl), 412 (M+ꢀCoCl2); Anal. Calc. for C28H32N2O·
CoCl2: C, 62.00; H, 5.95; N, 5.16. Found: C, 61.65; H,
5.89; N, 4.90%.
3.4. X-ray crystal structure determination of ligand 1
and complex 4
3.2.3. [2,6-Diformyl-4-tetra-buthyl-phenoxy
(2,4,6-trimethylanil)]CoCl2 (6)
Both intensity data sets were collected at 293K on a
Nonius KappaCCD diffractometer with graphite-
,
Similarly, ligand 3 reacted with CoCl2·6H2O to give
complex 6 in 45% yield as a green powder: m.p.\
300 °C. IR (KBr): 3435 (br, s), 2960, 2915 (m), 1638
(s), 1591 (s), 1539 (m), 1479 (m), 1239, 1201, 1148(m),
1063, 1028(m) cm−1; FABMS (m/z): 534 (M+ꢀCl), 498
(M+ꢀ2Cl), 441 (M+ꢀCoCl2); Anal. Calc. for
C30H36N2O·CoCl2: C, 63.16; H, 6.36; N, 4.91. Found:
C, 62.80; H, 6.23; N, 4.91%.
monochromated Mo–Ka radiation (u=0.71073 A).
Cell parameters were obtained by the global refinement
of the positions of all collected reflections. Intensities
were corrected by Lorentz and polarization effects and
empirical absorption. Both structures were solved by
direct method, and refined by full-matrix least-squares
on F2, using SHELX-98 package [13]. For ligand 1, all
non-H atoms were refined anisotropically. The hydro-
gen atom was found from the different Fourier map.
For complex 4, several methyl carbon atoms, C21, C22,
C32, C35, C36 were assigned into two positions, the
two type structures were refined to occupancies of
0.56(1) and 0.44(1), respectively. In addition, C23 was
also assigned into two positions with occupancies of
0.70(1) and 0.30(1), respectively. The hydrogen atoms
of the water molecules were found from the different
Fourier map, however, refined using riding model.
Crystallographic parameters for ligand 1 and complex 4
are collected in Table 3. Detail crystallographic data
(excluding structure factors) for the structures reported
in this paper have been deposited at the Cambridge
Crystallographic Data Centre and allocated the deposi-
tion numbers CCDC 167796 and 167797.
3.3. Complexation with (DME)NiBr2
3.3.1. [2,6-Diformyl-4-tetra-butyl-phenoxy(2,6-
diisopropylanil)]NiBr2 (7)
(DME)NiBr2 (77 mg, 0.25 mmol) and 2,6-diformyl-4-
tetra-butyl-phenoxy (2,6-diisopropylanil) (167 mg, 0.32
mmol) were combined in a Schlenk flask under an N2
atmosphere. CH2Cl2 (10 ml) was added, and the reac-
tion mixture was stirred at room temperature for 24 h.
The supernatant liquid was removed, and the product
was filtrated, washed with 3×4 ml of Et2O and dried
to give 139 mg of 7 in 73% yield: m.p. 238 °C (dec.). IR
(KBr): 3389 (br), 2964 (m), 1637 (s), 1538 (s), 1463 (m),
1390 (m), 1363, 1328,1289, 1234, 1177 (m), 1060 (m)
cm−1; FABMS (m/z): 663 (M+ꢀBr), 582 (M+ꢀ2Br),
525 (M+ꢀNiBr2); Anal. Calc. for C36H48N2ONiBr2·
H2O: C, 56.80; H, 6.62; N, 3.68. Found: C, 56.80; H,
6.37; N, 3.52%.
3.5. General procedure for ethylene oligomerization
A flame dried three-neck round flask was vacuated-
filled three times by nitrogen. Then ethylene was
charged with 50 ml of freshly distilled toluene and
stirred. At the room temperature, the aluminum cocata-
lyst MAO was added via syringe. The solution was
stirred for 10 min, then the precatalyst complex (4–9,
in 5 ml toluene) was added to the reaction mixture via
syringe. The reaction mixture was stirred under 1 atm
ethylene pressure for 30 min, and the oligomerization
was terminated with acidified ethanol. An aliquot of the
reaction mixture was analyzed by GCMS. Their activity
and distribution for the oligomers were collected in the
Tables 3 and 4.
3.3.2. [2,6-Diformyl-4-tetra-butyl-phenoxy(2,6-
dimethylanil)]NiBr2 (8)
The procedure described as above Section 3.3.1 by
using ligand 2 and (DME)NiBr2 gave a complex 8 in
85% yield as a light brown powder: m.p. 208 °C (Dec).
IR (KBr): 3391 (br), 2961 (m), 1640 (s), 1535 (s), 1472
(s), 1400, 1364, 1334, 1292 (w), 1238, 1182 (m) cm−1
;
FABMS (m/z): 551 (M+ꢀBr), 471 (M+ꢀ2Br), 414 (M+
ꢀNiBr2); Anal. Calc. for: C28H32N2ONiBr2·H2O: C,
51.81; H, 5.28; N, 4.32. Found: C, 51.47; H, 5.62; N,
3.97%.
3.3.3. 2,6-Diformyl-4-tetra-butyl-phenoxy(2, 4,
6-trimethylanil) NiBr2 (9)
4. Supplementary material
Similarly, the reaction of ligand 3 and (DME)NiBr2
gave a complex 9 in 85% yield as a light brown powder:
m.p. 202 °C (Dec). IR (KBr): 3380 (br), 2960 (m), 1638
(s), 1536 (s), 1364, 1330, 1292 (w), 1239, 1200 (m),
Full information on the crystal structure can be
ordered from the CCDC, 12 Union Road, Cambridge
CB2 1EZ, UK (fax: +44-1223-336-033; e-mail: de-

64
L. Wang et al. / Journal of Organometallic Chemistry 650 (2002) 59–64
Table 4
Acknowledgements
Crystal Data, collection parameters, and refinements for C36H48N2O
(1) and C36H48N2O·CoCl2·2H2O (4)
We are grateful for financial supports from the Chi-
nese Academy of Sciences under Core Research for
Engineering Innovation KGCX203-2 and Fund of ‘One
Hundred Talents’. We thank Steven Schultz for English
proof reading.
Ligand 1
Complex 4
Empirical formula
C36H48N2O
C36H48N2O·CoCl2·
2H2O
689.62
Formula weight
Space group
Crystal system
524.76
P21/n
P212121
orthorhombic
14.5582(3)
16.5895(4)
16.8190(2)
90
4062.0(14)
4
0.17×0.35×0.40
Green
monoclinic
9.9570(2)
17.4138(3)
19.0076(4)
99.5295(3)
3250.23(11)
4
,
a (A)
,
References
b (A)
,
c (A)
i (°)
[1] S.D. Ittel, L.K. Johnson, M. Brookhart, Chem. Rev. 100
(2000) 1169.
[2] G.J.P. Britovsek, V.C. Gibson, D.F. Wass, Angew. Chem. Int.
Ed. 38 (1999) 428.
[3] L.K. Johnson, S. Mecking, M. Brookhart, J. Am. Chem. Soc.
118 (1996) 267.
[4] C.M. Killian, D.J. Tempel, L.K. Johnson, M. Brookhart, J.
Am. Chem. Soc. 118 (1996) 11664.
[5] L.K. Johnson, C.M. Killian, M. Brookhart, J. Am. Chem.
Soc. 117 (1995) 6414.
[6] S. Mecking, L.K. Johnson, L. Wang, M. Brookhart, J. Am.
Chem. Soc. 120 (1998) 888.
[7] J. Heinemann, R. Mulhupt, P. Brinkmann, G. Luinstra,
Macromol. Chem. Phys. 200 (1999) 384.
[8] B.L. Small, M. Brookhart, A.M.A. Bennett, J. Am. Chem.
Soc. 120 (1998) 4049.
3
,
V (A )
Z
Crystal dimensions (mm) 0.40×0.40×0.17
Crystal color
Yellow
1.072
0.063
Dcalc (g cm−3
)
1.128
0.586
Absorption coefficient
(mm−1
)
qmax (°)
Diffractometer
27.51
29.16
NONIUS
KappaCCD
293(2)
7380
48396
NONIUS
KappaCCD
293(2)
10 833
74 180
T (K)
Independent reflections
Reflections collected
Independent reflections
observed [I\2|(I)]
5559
7473
,
Wave length (A)
R (F)
0.71073
0.0649
0.1719
1.018
0.346
−0.296
0.71073
0.0597
0.1587
1.024
0.652
−0.439
[9] G.J.P. Britovsek, V.C. Gibson, B.S. Kimberley, P.J. Maddox,
S.J. McTavish, G.A. Solan, A.J.P. White, D.J. Williams,
Chem. Commun. (1998) 849.
[10] C. Wang, S. Friedrich, T.R. Younkin, R.T. Li, R.H.
Grubbs, D.A. Bansleben, M.M. Day, Organometallics 17
(1998) 3149.
wR
Goodness-of-fit on F2
−3
,
Dzmax (e A
)
−3
,
Dzmin (e A
)
[11] B.L. Small, M. Brookhart, J. Am. Chem. Soc. 120 (1998)
7143.
[12] R.S. Drago, M.J. Desmond, B.B. Corden, K.A. Miller, J. Am.
Chem. Soc. 105 (1983) 2287.
[13] G.M. Sheldrick, SHELXTL Version 5.1, Bruker Analytical X-ray
Instruments Inc, Madison, WI, USA, 1998.
posit@ccdc.cam.ac.uk or www:http://www.ccdc.ac.uk),
upon request, quoting the deposition number CCDC
167796 and 167797.