Late transition metal complexes bearing 2,9-bis(imino)-1,10-phenanthrolinyl ligands: Synthesis, characterization and their ethylene activity

Article abstract of DOI:10.1016/S0022-328X(02)01623-6

A series of iron, cobalt and nickel halide complexes, LMX₂ (M = Fe, X = Cl; M = Co, X = Cl; M = Ni, X = Br) bearing 2,9-bis(imino)-1, 10-phenanthrolinyl ligands [L = 2,9-(ArNCH)₂C₁₂H₆N₂] were synthesized. The solid-state structures of 4 and 7 have been determined by single-crystal X-ray diffraction study. Treatment of the complexes LMX₂ with methylaluminoxane (MAO) leaded to activate ethylene as oligomerization catalysts.

Full text of DOI:10.1016/S0022-328X(02)01623-6

Journal of Organometallic Chemistry 658 (2002) 62Á70
/
www.elsevier.com/locate/jorganchem
Late transition metal complexes bearing 2,9-bis(imino)-1,10-
phenanthrolinyl ligands: synthesis, characterization and their ethylene
activity
Leyong Wang a, Wen-Hua Sun a,*, Lingqin Han a,b, Haijian Yang a, Youliang Hu a,
Xianglin Jin c
a State Key Laboratory of Engineering Plastics and Center for Molecular Sciences, Institute of Chemistry, The Chinese Academy of Sciences, Beijing
100080, People’s Republic of China
b College of Chemistry and Environmental Science, Hebei University, Baoding 071002, People’s Republic of China
c Institute of Physical Chemistry, Peking University, Beijing 100871, People’s Republic of China
Received 5 March 2002; received in revised form 1 April 2002; accepted 25 May 2002
Abstract
A series of iron, cobalt and nickel halide complexes, LMX2 (Mꢀ
/
Fe, Xꢀ
/
Cl; Mꢀ
/
Co, Xꢀ
/
Cl; Mꢀ
/
Ni, Xꢀ/Br) bearing 2,9-
bis(imino)-1,10-phenanthrolinyl ligands [Lꢀ2,9-(ArNCH)2C12H6N2] were synthesized. The solid-state structures of 4 and 7 have
/
been determined by single-crystal X-ray diffraction study. Treatment of the complexes LMX2 with methylaluminoxane (MAO)
leaded to activate ethylene as oligomerization catalysts. # 2002 Elsevier Science B.V. All rights reserved.
Keywords: Iron; Cobalt; Nickel; Phenanthrolinyl ligands; Crystal structures
1. Introduction
weight polyethylene for the first time with cationic
Ni(II) a-diimine complexes, has revived the investigation
of late transition metal complexes as potential catalyst
Olefin polymerization and oligomerization catalyzed
by transition metal complexes have attracted great
attentions in both academic and industrial research
[1,2]. Driven by industry for increasing control over
microstructures of olefin polymerization along with
advances in the understanding of homogeneous poly-
merization systems, the development of option has
observed from heterogeneous systems of the classical
precursors [7Á10]. These catalyst systems incorporated
/
polar monomers such as methyl acrylate into ethylene
and propylene copolymers along with relatively good
productivities [11,12].
The idea that metal complexes could process poly-
merization has stimulated a search for late transition
metal complexes as polymerization catalysts. Laine
group reported pyridinylimino-based nickel(II), cobal-
t(II) and palladium(II) complexes as alkene polymeriza-
ZieglerÁ
site catalysts, such as Group 4 metallocenes and
‘constrained geometry’ catalysts [3Á6]. The development
/
Natta technology to more sophisticated single-
/
tion catalyst [13Á15]. Brookhart [16] and Gibson group
/
of non-metallocene transition metal catalysts, particu-
larly the discovery of highly active systems based with
late-transition metal complexes, have signposted the
way forward to further develop in catalytic olefin
polymerization. The disclosure by the group of Broo-
khart in 1995, in which they produced high molecular
[17] have reported highly active ethylene polymerization
catalysts based on iron(II) and cobalt(II) complexes
bearing 2,6-bis(imino)pyridyl ligands. Modification of
substituents on their aryl (Ar) and imino groups resulted
in dramatic changes for the productivity and physical
properties of the corresponding polyolefin materials
[18Á22]. In addition, we were interested in exploring
/
and synthesizing some new ligands in order to develop
new late-transition metal complexes as catalysts in olefin
polymerization and oligomerization [23]. Here we de-
* Corresponding author. Tel.: ꢁ
6255-9373
E-mail address: whsun@infoc3.icas.ac.cn (W.-H. Sun).
/
86-10-6255-7955; fax: ꢁ86-10-
/
0022-328X/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 2 - 3 2 8 X ( 0 2 ) 0 1 6 2 3 - 6

L. Wang et al. / Journal of Organometallic Chemistry 658 (2002) 62Á
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70
63
Scheme 1. Synthesis of compounds 1Á9. Reagents and conditions: (i) EtOH, HAc; (ii) FeCl2, THF; (iii) CoCl2, EtOH; (iv) (DME)NiBr2, CH2Cl2.
/
scribe the synthesis of a novel series of iron, cobalt and
nickel complexes bearing 2,9-bis(imino)-1,10-phenan-
throlinyl ligands (Scheme 1). Their nickel and cobalt
complexes, with the assistance of methylaluminoxane
(MAO), could activate ethylene for oligomerization to
produce oligomers.
(1,2-dimethoxyethane)nickel(II) bromide in dichloro-
methane (Scheme 1). Their resulting solutions were
concentrated, and diethyl ether was added to make the
products precipitated. The products were purified by
washing with diethyl ether for removing non-reacted
ligand. Complexes 1Á9 are air-stable in solid, and
/
insoluble in saturated hydrocarbons, whereas they are
soluble in polar organic solvents, such as CH2Cl2,
CHCl3, ethanol and acetonitrile.
2. Results and discussion
The complexes obtained were fully characterized by
IR, FABMS and elemental analysis. In the FABMS
2.1. Synthetic aspects
spectra of complexes 1Á9, although ion peak of complex
/
was not observed (except for complex 1), fairly intensive
fragments were obtained upon elimination of one and
two halide and then FeCl2 (CoCl2, NiBr2). To confirm
their structures, complexes 4, 7 were subjected to single-
crystal X-ray diffraction studies.
2,9-Bis(imino)-1,10-phenanthrolinyl ligands L1, L2,
L3 were prepared in good yields by the condensation
reaction of two equivalents of the appropriate aniline
with one equivalent of 2,9-dialdehyde-1,10-phenanthro-
line (Scheme 1), yielding pale yellow crystalline products
after being purified through re-crystallization in ethanol.
The L1, L2, L3 were characterized by microanalysis, 1H-
NMR spectra and mass spectrometry.
2.2. X-ray crystallography
The complexes 1Á
yields by treating MCl2 (Mꢀ
/
6 were synthesized in reasonable
Fe, Co) with the corre-
Crystals of complexes 4, 7 suitable for X-ray struc-
tural determination were grown by vapor diffusion of
/
sponding 2,9-bis(inimo)-1,10-phenanthrolinyl ligand in
appropriate solvents (Fe, THF; Co, ethanol) at elevated
temperature, while the nickel(II) dibromide complexes
Et2O into the acetonitrileÁdichloromethane solution (4)
/
and acetonitrile solution (7), respectively. The molecular
structure of complex 4 is shown in Fig. 1. In this
complex, the structure consists of a metal atom
surrounded by one ligand L1 and two chlorine atoms
7Á/9 were prepared with the corresponding ligands by
reacting of a slight excess of the diimino ligand with

64
L. Wang et al. / Journal of Organometallic Chemistry 658 (2002) 62Á70
/
Fig. 1. Crystal structure of complex 4 with 30% probability displacement ellipsoids.
in a distorted trigonalÁ
positions are occupied by cobalt with two nitrogen
atoms N(1) and N(3) [N(1)ÃCoÃN(3)ꢀ149.83(6)8]. The
equatorial plane is made by the two chlorine atoms and
a nitrogen atom N(2) of the phenanthroline fragment.
The equatorial plane and the axial plane make a
dihedral angle of 88.48. The metal center is coordinated
with N(2), N(3) in the rigid ring of 1, 10-phenanthroline
and N(1) of the imino group for forming two fused five-
/
bipyramidal geometry. The axial
In complex 7, Br(1) was disordered into two positions,
and C(39) of acetonitrile lies in a special position (xꢀ
0.000; yꢀ 0.2391(5); zꢀ0.2500), that is to say that
/
/
/
/
/
ꢂ
/
/
C(39) of acetonitrile is in the 2-fold rotation axis,
therefore X-ray analysis of complex Ni reveals that the
crystal contains not only 5-coordinated species (Fig. 2)
that is often observed in similar Ni complexes but also 6-
coordinated ones (Fig. 3). The 6-coordinate structure
consists of a metal atom surrounded by one ligand L1,
two bromine atoms and one CH3CN linked by the N
atoms, in a distorted octahedral geometry. The metal
center is coordinated to N(2) and N(3) of the rigid 1,10-
phenanthroline and N(1) of one imino group forming
membered rings with acute NÃ
N(2)ꢀ76.82(7)8, N(2)ÃCoÃN(1)ꢀ
N(2) and CoÃN(3) bonds are significantly shorter than
the CoÃN(1) (imino) bonds, with the formed double
bond character of the imino linkage N(1)ÃC(26) have
/
MÃ
/
N angles: N(3)Ã
/
CoÃ
/
/
/
/
/
73.08(6)8. The CoÃ
/
/
/
/
two fused 5-membered rings (Table 2) with acute NÃ
NiÃN angles: N(1)ÃNiÃN(2)ꢀ77.42(12)8; N(2)ÃNiÃ
N(3)ꢀ77.95(11)8. These three nitrogen atoms occupy
/
˚
been retained [CÄ
diisopropylphenyl substituents C(27)Ã
C(30)ÃC(31)ÃC(32) are oriented ca. orthogonal to the
basal coordination plane N(1)ÃC(26)ÃC(3)ÃN(2)Ã
C(24)ÃC(25)ÃN(3)ÃCo(1), with the ca 85.28 twist about
the N(1)ÃC(27) bond. Selected bond lengths and angles
/N distances in 1.276(2) A]. The 2,6-
/
/
/
/
/
/
/
C(28)ÃC(29)Ã
/
/
/
/
/
/
/
/
/
Table 2
˚
Selected bond lengths (A) and angles (8) for complex 7
/
/
/
/
˚
Bond lengths (A)
of complex 4 are presented in Table 1.
Br(1A)ÃNi(1)
Br(2)ÃNi(1)
Ni(1)ÃN(1)
Ni(1)ÃN(5)
N(1)ÃC(1)
N(2)ÃC(14)
N(3)ÃC(24)
N(4)ÃC(27)
C(13)ÃC(14)
2.3039(11) Br(1B)ÃNi(1)
2.4944(7) Ni(1)ÃN(2)
2.5311(9)
1.969(3)
2.188(3)
1.279(4)
1.327(4)
1.343(4)
1.248(4)
1.160(7)
1.469(3)
2.187(3)
2.195(5)
1.441(4)
1.330(4)
1.362(4)
1.436(4)
1.486(3)
Ni(1)ÃN(3)
N(1)ÃC(13)
N(2)ÃC(25)
N(3)ÃC(23)
N(4)ÃC(26)
N(5)ÃC(40)
C(23)ÃC(26)
Table 1
˚
Selected bond lengths (A) and angles (8) for complex 4
˚
Bond lengths (A)
Co(1)ÃN(2)
Co(1)ÃCl(1)
Co(1)ÃN(1)
N(1)ÃC(27)
N(2)ÃC(24)
N(3)ÃC(25)
N(4)ÃC(4)
2.0428(17) Co(1)ÃCl(2)
2.2501(8)
Co(1)ÃN(3)
2.4352(18) N(1)ÃC(26)
2.2299(8)
2.2503(18)
1.276(2)
1.331(2)
1.329(3)
1.259(3)
1.486(3)
1.449(2)
1.351(2)
1.370(2)
1.433(3)
1.469(3)
N(2)ÃC(23)
N(3)ÃC(14)
N(4)ÃC(13)
C(13)ÃC(14)
Bond angles (8)
N(2)ÃNi(1)ÃN(1)
N(1)ÃNi(1)ÃN(3)
N(1)ÃNi(1)ÃN(5)
77.42(12) N(2)ÃNi(1)ÃN(3)
155.02(11) N(2)ÃNi(1)ÃN(5)
93.52(15) N(3)ÃNi(1)ÃN(5)
77.95(11)
170.75(15)
110.93(14)
94.59(8)
C(23)ÃC(26)
N(2)ÃNi(1)ÃBr(1A) 113.46(8) N(1)ÃNi(1)ÃBr(1A)
Bond angles (8)
N(3)ÃNi(1)ÃBr(1A)
N(2)ÃNi(1)ÃBr(2)
N(3)ÃNi(1)ÃBr(2)
Br(1A)ÃNi(1)ÃBr(2) 152.62(4) N(2)ÃNi(1)ÃBr(1B)
N(1)ÃNi(1)ÃBr(1B)
N(5)ÃNi(1)ÃBr(1B)
91.39(7) N(5)ÃNi(1)ÃBr(1A)
92.60(8) N(1)ÃNi(1)ÃBr(2)
85.82(7) N(5)ÃNi(1)ÃBr(2)
64.91(13)
99.37(8)
N(2)ÃCo(1)ÃCl(2)
Cl(2)ÃCo(1)ÃCl(1)
Cl(2)ÃCo(1)ÃN(3)
N(2)ÃCo(1)ÃN(1)
Cl(1)ÃCo(1)ÃN(1)
121.37(5)
115.42(3)
97.82(5)
73.08(6)
100.93(5)
N(2)ÃCo(1)ÃCl(1)
N(2)ÃCo(1)ÃN(3)
Cl(1)ÃCo(1)ÃN(3)
Cl(2)ÃCo(1)ÃN(1)
N(3)ÃCo(1)ÃN(1)
123.19(5)
76.82(7)
97.14(5)
95.97(5)
149.83(6)
90.70(13)
95.38(8)
89.24(7)
88.98(8) N(3)ÃNi(1)ÃBr(1B)
82.46(13) Br(2)ÃNi(1)ÃBr(1B) 169.54(3)

L. Wang et al. / Journal of Organometallic Chemistry 658 (2002) 62Á
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70
65
Fig. 2. Crystal structure of complex 7 in which Ni is 5-coordinated, with 30% probability displacement ellipsoids.
the equatorial plane which also contains the N(5) atom
of the acetonitrile, whereas the axial position are
occupied by nickel with two bromine. All the atoms of
1,10-phenanthroline ligand and the C(13), N(1), C(26)
and N(4) of the imino groups as well as the Ni(1) atom
and N(5) of CH3CN make an almost perfect plane, with
N(1)Ã
/
C(1) bond. Selected bond lengths and angles for
complex 7 are presented in Table 2.
In this complex 7, the 5-coordinate structure (Fig. 2)
consists of a metal atom surrounded by one ligand L1
and two bromine atoms in a distorted trigonalÁ
amidal geometry. The axial positions are occupied by
nickel with two nitrogen atoms N(1) and N(3) [N(1)Ã
NiÃN(3)ꢀ155.02(11)8]. The equatorial plane is made
/bipyr-
/
˚
the largest deviation from the plane being 0.0776 A at
C(14). The 2,6-diisopropylphenyl substituents C(27)Ã
C(28)ÃC(29)ÃC(30)ÃC(31)ÃC(32) are oriented ca.
orthogonal to the basal coordination plane N(1)Ã
C(13)ÃC(14)ÃN(2)ÃC(25)ÃC(24)ÃN(3)ÃNi(1) (ca
1048); however the 2,6-diisopropylphenyl group C(1)Ã
C(2)ÃC(3)ÃC(4)ÃC(5)ÃC(6) is oriented to the basal
coordination plane N(1)ÃC(13)ÃC(14)ÃN(2)ÃC(25)Ã
C(24)ÃN(3)ÃNi(1), with the ca 64.68 twist about the
/
/
/
by the two bromine atoms and a nitrogen atom N(2) of
the phenanthroline fragment. The equatorial plane and
the axial plane make a dihedral angle of 87.18.
/
/
/
/
/
/
/
/
/
/
/
/
2.3. Oligomerization of ethylene
/
/
/
/
/
/
/
/
/
Upon treatment with methylaluminoxane(MAO), at 1
bar pressure, no activity was found for all complexes 1Á
/
/
/
Fig. 3. Crystal structure of complex 7 in which Ni is 6-coordinated, with 30% probability displacement ellipsoids.

66
L. Wang et al. / Journal of Organometallic Chemistry 658 (2002) 62Á70
/
9. Increasing the pressure of ethylene to 10 bar, as seen
from Table 3, the nickel and cobalt complexes 4Á9 are
active for ethylene oligomerization. Catalyst activities
were calculated on the base of GCÁMS analysis, and
Table 3 listed their activity and distribution of oligomers
in the oligomerization with nickel and cobalt precata-
techniques. Solvents were refluxed over an appropriate
drying agent and distilled and degassed prior to use.
Elemental analyses were performed on a Hezaeous
CHN-RAPID microanalyzer. NMR spectra were re-
corded on a Bruker DMX-300 spectrometer, with TMS
as the internal standard. IR spectra were obtained as
/
/
lysts 4Á/9. Table 4 shows the structures and ratios of
KBr pellets on a PerkinÁElmer FTIR 2000 Spectro-
/
product C4 and C6, however, it is not clear about the
double bond immigration, especially for the rearrange-
ment of oligomers. During the oligomerization reaction,
a decrease in activity is notified with the final activity
meter. Mass spectra were measured on a Kratos AEI
MS-50 instrument using fast atom bombardment (FAB)
or electron impact (EI) technology. Tm of PE was
measured on a PerkinÁElmer DSC-7A Spectrometer.
/
being typically 10Á
/
15% of the initial activity. The nature
Melting points were determined with a digital electro-
thermal apparatus without furher correction. Distribu-
tion for the oligomerization was recorded on a HP5890
Series II gas chromatogram spectrometer.
of the metal center has a major influence on catalytic
activity. In general, Ni catalysts are more active than the
corresponding Co(II) analogues in our research condi-
tion. The most active Ni(II) catalyst is complex 7 (3.3ꢃ
106 g molꢂ1 h), while the most active Co(II) complexes
is complex 6 (9.3ꢃ
105 g molꢂ1 h) for oligomerization
of ethylene. As seen from Table 3, in addition to the
toluene-soluble fraction of oligomers, catalysts 4Á7 and
/
Compound 1, 10-phenanthroline-2,9-dicarboaldehyde
was prepared according to an established procedure
[24,25], while MAO (1.4 mol lꢂ1) 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
other chemicals were obtained commercially without
purification unless stated otherwise.
/
/
9 also yield a small toluene-insoluble PE fraction, which
was confirmed by DSC. However, the iron complexes
1Á3 show almost no activity for ethylene oligomeriza-
/
tion, although some consumption of ethylene was
observed during the reaction, but small amount of solid
polyethylene (run 2) was found. It appears that com-
pared with iron(II) and cobalt(II) complexes bearing
2,6-bis(imino)pyridyl ligands [16,17,22], the active site of
the present complexes might too wide to suppress
undesired b-H elimination.
3.2. Preparations of 2,9-bis(imino)-1,10-phenanthrolinyl
ligands
3.2.1. 2,9-Diformyl-1,10-phenanthrolinebis(2,6-
diisopropylanil) (L1)
To a refluxing solution of 1, 10-phenanthroline-2,9-
dicarboaldehyde (1.0 g, 4.2 mmol) and a few drops of
glacial acetic acid in anhydrous ethanol (120 ml) was
added 2,6-diisopropylaniline (4.0 g, 20 mmol) in anhy-
drous ethanol (50 ml) over a period of 30 min with
stirring. Then the mixture was refluxed for further 5 h.
Upon cooling to room temperature (r.t.), the solution
was evaporated to 30 ml under vacuum, and the product
was crystallized from ethanol. After filtration, the
3. Experimental
3.1. General
All manipulations were carry out under an atmo-
sphere of nitrogen using standard Schlenk and cannula
Table 3
Complexes activity and distribution of oligomers
a
b
Run Precat (mmol)
MAO
(mmol per equiv)
P
Activity
Mass of PE
(mg)
Tm of PE
(8C)
Distribution of the oligomerization
(bar) (g molꢂ1 hꢂ1
)
C4 (g)
C6 (g)
C8 (g)
C10 (g)
1
2
3
4
5
6
7
8
9
1(8.4)
2(16)
3(10)
4(10)
5(10)
6(10)
7(14)
8(17)
9(10)
10(1190)
10(625)
20
20
20
80
133.13
10(1000)
10(1000)
10(1000)
10(1000)
10(710)
10
10
20
20
20
10
7.0ꢃ105
7.1ꢃ105
9.3ꢃ105
3.3ꢃ106
2.1ꢃ106
2.0ꢃ106
30
133.75
124.78
125.56
120.27
3.5
2.54
4.2
480
30
0.54
0.26
11.1
5.8
0.18
5.4
230
4.0
11.0
3.60
2.0
10(590)
10(1000)
0.96
1.23
105
117.97
5.2
a
Toluene solvent, reaction time 0.5 h.
Determined by DSC.
b

L. Wang et al. / Journal of Organometallic Chemistry 658 (2002) 62Á
/
70
67
Table 4
The structures and ratios of product C4 and C6
yellow solid was washed with cold ethanol and dried to
6.85 (4H, m), 7.90 (2H, s), 8.38 (2H, d), 8.43Á
m); FABMS (m/z): 471(Mꢁꢁ
C32H30N4H2O×
C, 78.29; H, 6.31; N, 11.06%.
/
8.86 (4H,
give yellow crystal 1.56 g in 62% yield. M.p. 269Á
/
/
1); Anal. Calc. for
H2O: C, 78.66; H, 6.60; N, 11.47. Found:
270 8C; IR(KBr): 3063 (s), 2962 (s), 1639 (vs), 1586
(s), 1550, 1499, 1462 (m), 1383, 1363, 1251, 1182, 1086,
/
1
933 (m), 860, 756 (s) cmꢂ1; H-NMR (CDCl3): d 1.18
(24H, d, Jꢀ
7.99 (2H, s), 8.47 (2H, d, Jꢀ
/
10.2Hz), 3.05 (4H, m), 7.15Á
/
7.23 (6H, m),
3.3. Complexation with MCl2 (MꢀFe, Co) and DME
NiBr2
/
/
7Hz), 8.75 (2H, d, Jꢀ
/
7Hz), 8.78 (2H, s); EIMS (m/z): 554 (Mꢁ, 88.7%), 553
(23.0%), 539 (22.1%), 511 (10.8%), 381 (13.4%), 369
(31.4%), 364 (12.4%), 352 (15.6%), 208 (18.9%), 207
(13.5%), 194 (100.0%), 193 (15.1%), 186 (24.9%), 181
(40.5%), 176 (20.8%), 146 (13.8%); Anal. Calc. for
C38H42N4: C, 82.27; H, 7.63; N, 10.10. Found: C,
81.98; H, 7.90; N: 9.72%.
3.3.1. Preparation of [2,9-diformyl-1,10-
phenanthrolinebis(2,6-diisopropylanil)]FeCl2 (1)
A solution of 2,9-diformyl-1,10-phenanthroline(2,6-
diisopropylanil) (197 mg, 0.33 mmol) in THF (10 ml)
was added dropwise at 60 8C to a solution of FeCl2×
/
4H2O (60 mg, 0.30 mmol) in THF (5 ml) to yield a blue
solution. After stirring at 60 8C for 18 h, the reaction
mixture was allowed to cool to r.t. The reaction volume
was concentrated, and diethyl ether (10 ml) was added
to precipitate the product as a green power, which was
3.2.2. 2,9-Diformyl-1,10-phenanthrolinebis(2,6-
dimethylanil) (L2)
By using similar procedure described in synthesis of
Ligand L1, we obtained L2 as yellow crystal in 58%
subsequently washed with diethyl ether (3ꢃ10 ml),
/
yield. M.p. 132Á133 8C; IR(KBr): 3449 (m), 3325 (m),
/
filtered, and dried in vacuo to afford 135 mg (65%) of
2,9-diformyl-1,10-phenanthroline(2,6-diisopropylanil)
3018 (m), 2969, 2918 (m), 1636 (vs), 1591, 1550 (s), 1500,
1
1474, 1442 (s), 1192, 1088 (s), 861, 762 (s) cmꢂ1; H-
FeCl2. M.p.ꢀ
2868 (m), 1633, 1503, 1461 (s) cmꢂ1; FABMS (m/z): 680
(Mꢁ), 646 (MꢁꢂCl), 610 (Mꢁꢂ
2Cl); Anal. Calc. for
H2O: C, 65.24; H, 6.34; N, 8.01.
/
320 8C; IR(KBr): 3441 (br), 2963 (s),
NMR (CDCl3): d 2.18 (12H, s), 6.94Á/7.14 (6H, m), 8.05
(2H, s), 8.42Á
/
8.52 (2H, d), 8.75Á
/
8.86 (4H, m); EIMS (m/
z): 442 (Mꢁ, 100%), 441 (39.5%), 427 (14.9%), 424
(16.7%), 337 (28.4%), 324 (18.2%), 323 (53.2%), 322
(14.1%), 311 (25.2%), 310 (64.7%), 309 (14.3%), 308
(11.4%), 296 (14.1%), 295 (10.5%),132 (13.5%); Anal.
/
/
C38H42N4 FeCl2×
/
Found: C, 65.12; H, 6.38; N, 7.80%.
Calc. for C30H26N4×
/
1/2H2O: C, 79.79; H, 6.03; N, 12.41.
3.3.2. Preparation of [2,9-diformyl-1,10-
Found: C, 79.86; H, 6.41; N, 12.13%.
phenanthrolinebis(2,6-dimethylanil)]FeCl2 (2)
By using same procedure described above in synthesis
of complex 1, the reaction of L2 and FeCl2 4H2O gave 2
3.2.3. 2,9-Diformyl-1,10-phenanthrolinebis(2,4,6-
trimethylanil) (L3)
as green powder in 87% yield. M.p.ꢀ320 8C; IR(KBr):
/
By using similar procedure described in synthesis of
Ligand L1, we obtained L3 as yellow crystal in 77%
3403 (br), 2959 (s), 1641, 1617 (vs), 1508, 1468 (s), 1381,
1304 (s), 1223, 1177 (s), 862, 776 (s) cmꢂ1; FABMS (m/
yield. M.p. 166Á
/
167 8C; IR(KBr): 3394 (br), 1724 (s),
z): 534 (Mꢁꢂ
/
Cl), 498 (Mꢁꢂ
2Cl); Anal. Calc. for
/
1633 (vs), 1553 (m), 1499, 1480 (s), 1208 (s), 854 (s)
1
C30H26N4 FeCl2 H2O: C, 50.46; H, 3.95; N, 7.85.
Found: C, 50.86; H, 3.65; N, 7.44%.
cmꢂ1; H-NMR (CDCl3): d 2.06 (12H, s), 2.23 (6H, s),

68
L. Wang et al. / Journal of Organometallic Chemistry 658 (2002) 62Á70
/
3.3.3. Preparation of [2,9-diformyl-1,10-
phenanthrolinebis(2,4,6-trimethylanil)]FeCl2 (3)
By using same procedure described above in synthesis
0.30 mmol) were combined in a Schlenk flask under N2
atmosphere. CH2Cl2 (10 ml) was added, and the
reaction mixture was stirred at r.t. for 18 h. The reaction
solution was concentrated into its half volume, and
diethyl ether (10 ml) was added to precipitate the
product as a green power, which was subsequently
of complex 1, the reaction of L3 and FeCl2×
as green powder in 91% yield. M.p. ꢀ320 8C; IR(KBr):
1610(s), 1570(s), 1502, 1479(s), 862(s) cmꢂ1; FABMS
(m/z): 561 (MꢁꢂCl), 526 (Mꢁꢂ
2Cl); Anal. Calc. for
H2O: C, 62.46; H, 5.24; N, 9.10.
/
4H2O gave 3
/
/
/
washed with diethyl ether (3ꢃ
to give 7 as orange powder 185 mg, yield: 86%. M.p. ꢀ
320 8C; IR(KBr): 3407(Br), 2963 (s), 1631, 1608, 1584
(s), 1503, 1401 (s) cmꢂ1; FABMS (m/z): 693 (Mꢁꢂ
Br),
612 (Mꢁꢂ
2Br); Anal. Calc. for C38H42N4NiBr2×
/
10 ml), filtered, and dried
C32H30N4 FeCl2×
/
/
Found: C, 62.04; H, 4.90; N, 8.65%.
/
3.3.4. Preparation of [2,9-diformyl-1,10-
/
/
phenanthrolinebis(2,6-diisopropylanil)]CoCl2 (4)
A
CH2Cl2: C, 54.58; H, 5.17; N, 6.53. Found: C, 54.09;
H, 4.86; N, 6.23%. Crystals of complexes 7 suitable for
X-ray structural determination was grown by vapor
diffusion of Et2O into acetonitrile solutions.
suspension of 2,9-diformyl-1,10-phenanthro-
line(2,6-diisopropylanil) (179 mg, 0.30 mmol) in ethanol
(60 ml) was added dropwise at 60 8C to a solution of
CoCl2 (70 mg, 0.30 mmol) in ethanol (5 ml) to yield a
blue solution. After stirring at 60 8C for 8 h, the
reaction mixture was cooled to r.t. The reaction volume
was concentrated, and diethyl ether (10 ml) was added
to precipitate the product as a green power, which was
3.3.8. Preparation of [2,9-diformyl-1,10-
phenanthrolinebis(2,6-dimethylanil)]NiBr2 (8)
By using same procedure described above in synthesis
of complex 7, the reaction of L2 and DME NiCl2 gave 8
subsequently washed with diethyl ether (3ꢃ
filtered, and dried in vacuum to afford 130 mg (60%) of
2,9-diformyl-1,10-phenanthroline(2,6-diisopropylanil)
/
10 ml),
as orange powder in 78% yield. M.p. ꢀ
/
320 8C;
FABMS: 582 (MꢁꢂBr), 501 (Mꢁꢂ
/
/
2Br); Anal. Calc.
For C30H26N4NiBr2 CH2Cl2: C, 49.91; H, 3.78; N, 7.51.
Found: C, 49.95; H, 3.51; N, 7.50%.
CoCl2. M.p. ꢀ
1615, 1586, 1566 (s), 1505, 1461 (s) cmꢂ1; FABMS (m/
z): 648 (MꢁꢂCl), 614 (Mꢁꢂ
2Cl); Anal. Calc. for
/
320 8C; IR(KBr): 2961, 2866 (s), 1639,
/
/
3.3.9. Preparation of [2,9-diformyl-1,10-
C38H42N4 CoCl2: C, 66.67; H, 6.18; N, 8.18. Found: C,
66.22; H, 5.71; N, 8.10%. Crystals of complexes 4
suitable for X-ray structural determination was grown
phenanthrolinebis(2,4,6-Trimethylanil)]NiBr2 (9)
By using same procedure described above in synthesis
of complex 7, the reaction of L3 and DME×
as orange powder in 78% yield. M.p.ꢀ
IR(KBr): 1629 (vs), 1569 (s) cmꢂ1. FABMS (m/z):
609 (MꢁꢂBr), 528 (Mꢁꢂ
2Br); Anal. Calc. for
/NiCl2 gave 9
by vapor diffusion of Et2O into acetonitrileÁ
/dichlor-
/
320 8C;
omethane solutions.
/
/
3.3.5. Preparation of [2,9-diformyl-1,10-
phenanthrolinebis(2,6-dimethylanil)]CoCl2 (5)
C32H30N4NiBr2 CH2Cl2: C, 51.21; H, 4.17; N, 7.24.
Found: C, 49.95; H, 3.57; N, 7.52%.
By using same procedure described above in synthesis
of complex 4, the reaction of L2 and CoCl2×6H2O gave 5
as green powder in 73% yield. M.p. ꢀ320 8C; IR(KBr):
1604, 1574 (vs), 1381 (vs), 1064 (s) cmꢂ1; FABMS (m/
z): 536 (MꢁꢂCl), 501 (Mꢁꢂ
2Cl); Anal. Calc. for
/
3.4. X-ray crystallstructure determination of complex 4
and complex 7
/
/
/
Complex 4s intensity data sets were collected at 293 K
C30H26N4 CoCl2: C, 62.95; H, 4.58; N 9.79. Found: C,
62.72; H, 4.67; N 9.34%.
on a Rigaku RAXIS RAPID IP diffractometer with
graphite-monochromated MoÁ
/
Ka radiation (lꢀ
/
˚
0.71073 A), while complex 7s intensity data sets were
collected at 123 (2) K on the same diffractometer with
3.3.6. Preparation of [2,9-diformyl-1,10-
phenanthrolinebis(2,4,6-trimethylanil)]CoCl2 (6)
By using same procedure described above in synthesis
graphite-monochromated MoÁ
/
Ka radiation (lꢀ
/
˚
0.71073 A), using the v Á
/
2u scan mode. Cell parameters
of complex 4, the reaction of L3 and CoCl2×
as green powder in 73% yield. M.p. ꢀ320 8C; IR(KBr):
3425 (br), 1612 (s), 1564, 1502, 1477 (s) cmꢂ1; FABMS
(m/z): 564 (MꢁꢂCl), 529 (Mꢁꢂ
2Cl); Anal. Calc. for
C32H30N4 CoCl2 H2O: C, 62.15; H, 5.22; N 9.06. Found:
C, 62.30; H, 4.98; N, 8.90%.
/
6H2O gave 6
were obtained by the global refinement of the positions
of all collected reflections. Intensities were corrected by
Lorentz and polarization effects and empirical absorp-
tions were applied. Both structures were solved by direct
method, and refined by full-matrix least-squares on F2,
using SHELX-97 package [26]. For complex 4, all non-H
atoms were refined anisotropically. For complex 7, Br(1)
was found to be disordered into two positions, these two
positions were refined to occupancies of 42 and 58%,
respectively, and C(39) of acetonitrile lies in a special
/
/
/
3.3.7. Preparation of [2,9-diformyl-1,10-
phenanthrolinebis(2,6-diisopropylanil)]NiBr2 (7)
(DME)NiBr2 (77 mg, 0.25 mmol) and 2,9-diformyl-
1,10-phenanthroline(2,6-diisopropylanil) (L1) (179 mg,
position (xꢀ
/
0.000; yꢀ
/
ꢂ
/
0.2391(5); zꢀ0.2500), that is
/

L. Wang et al. / Journal of Organometallic Chemistry 658 (2002) 62Á
/
70
69
Table 5
Crystal data, collection parameters, and refinements for complexes 4 and 7
Complexes
4
7
Empirical formula
Formula weight
Crystal color and form
Space group
C
684.59
38H42Cl2N4Co
C38 H42 Br2 N4 Ni×0.5CH3CN
793.81
Yellow, block
P21/n
Green, block
C2/c
Crystal system
˚
Monoclinic
9.7558(4)
14.7282(5)
24.9304(10)
94.6060(9)
3570.6(2)
4
Monoclinic
26.9439(10)
12.2608(4)
22.4878(8)
99.564(1)
7325.7 (5)
8
a (A)
˚
b (A)
˚
c (A)
b (8)
3
V (A )
˚
Z
T (K)
Dcalc (Mg mꢂ3
293(2)
1.274
123 (2)
1.439
)
Absorption coefficient (mmꢂ1
F (000)
)
0.662
1436
2.745
3256
Crystal size (mm)
Scan mode
0.40ꢃ0.30ꢃ0.08
0.70ꢃ0.60ꢃ0.25
v Á
/
2u
v Á2u
/
umax (8)
27.48
26 218
27.48
31 955
Number of collected reflections
Number of independent reflections
Number of parameters
7963
415
8233
442
Goodness-of-fit
0.730
0.686
Final R indices (I ꢀ2.00(s(I))
R indices (all data)
Largest differential peak and hole (e A
Rꢀ0.0379, wRꢀ0.0585
Rꢀ0.0973, wRꢀ0.0654
0.332 and ꢂ0.303
Rꢀ0.0373, wRꢀ0.0768
Rꢀ0.1022, wRꢀ0.0951
0.648 and ꢂ0.593
ꢂ1
˚
)
4. Supplementary material
to say that C(39) of acetonitrile is in the twofold
rotation axis, therefore acetonitrile was changed to line
Crystallographic data for the structures reported in
this paper have been deposited in the Cambridge
Crystallographic Data Centre with the deposited num-
bers CCDC Number169182 (Complex 4) and 169183
(Complex 7). Copies of the data can be obtained free of
charge from The Director, CCDC, 12 Union Road,
NÃ
/
CÃ
/
CÃ
/
CÃ
/
N in cell by the symmetrical operation.
This is addition of two part of disordered acetonitrile
which share terminal C atom. Their crystal data,
together with the diffraction data collection and struc-
ture refinement parameters are presented in Table 5.
Cambridge CB2 1EZ, UK (Fax: ꢁ44-1223-336033; e-
mail: deposit@ccdc.cam.ac.uk or www: http://
www.ccdc.cam.ac.uk).
/
3.5. General procedure for ethylene oligomerization
3.5.1. High pressure tests
A 100 ml autoclave was heated under vacuum at
80 8C for 3 h and cooled to the r.t. and then vacuated-
filled three times by nitrogen and once ethylene. Freshly
distilled toluene (50 ml) and the aluminum cocatalyst
MAO were introduced into the reactor, the autoclave
was sealed, and the ethylene pressure raised to required
pressure, and the mixture was stirred at the r.t. for 10
min. The autoclave was then vented, the precatalyst
solution/suspension was added, and the autoclave was
sealed and pressurized to the desired ethylene pressure
while stirring. The reaction was quenched by venting the
autoclave and followed by addition of with acidified
ethanol. The solid polethylene was collected through
filteration (if it was observed). Quantitative GC analysis
of this solution was performed using a weighed aliquot
of this solution with a weighed amount of toluene as
standard.
Acknowledgements
We are grateful to the Chinese Academy of Sciences
for financial support under the Fund of One Hundred
Talents and Core Research for Engineering Innovation
KGCX203-2. W.H.S., thank Professor Gerhard Erker
of Munster University and the Alexander von Hum-
¨
boldt-Stiftung. L.W. thanks China Postdoctoral Science
Foundation for partial financial support.
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