Nickel complexes bearing N,N,N-tridentate quinolinyl anilido-imine ligands: Synthesis, characterization and catalysis on norbornene addition polymerization

Article abstract of DOI:10.1016/j.jorganchem.2013.10.020

The N,N,N-tridentate quinolinyl anilido-imine ligands 2-(ArNC(H))C ₆H₄-HNC₉H₆N (L_aH, Ar = 2,6-Me₂C₆H₃; L_bH, Ar = 2,6- ⁱPr₂C₆

Full text of DOI:10.1016/j.jorganchem.2013.10.020

Journal of Organometallic Chemistry 749 (2014) 350e355
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Nickel complexes bearing N,N,N-tridentate quinolinyl anilidoeimine
ligands: Synthesis, characterization and catalysis on norbornene
addition polymerization
*
Zhiqiang Hao, Nan Yang, Wei Gao , Lan Xin, Xuyang Luo, Ying Mu
State Key Laboratory for Supramolecular Structure and Materials, School of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, People’s
Republic of China
a r t i c l e i n f o
a b s t r a c t
Article history:
The N,N,N-tridentate quinolinyl anilidoeimine ligands 2-(ArNC(H))C6H4eHNC9H6N (LaH, Ar ¼ 2,6-
Me2C6H3; LbH, Ar ¼ 2,6-iPr2C6H3) and 2-(C9H6N)NC(H)C6H4eHNAr (LcH, Ar ¼ 2,6-Me2C6H3; LdH,
Ar ¼ 2,6-iPr2C6H3) were synthesized and characterized. Reactions of these ligands with nBuLi and sub-
sequent additions of NiCl2(DME) afford the N,N,N-tridentate nickel complexes [2-(ArNC(H))C6H4eNC9H6N]
NiCl (Ar ¼ 2,6-Me2C6H3 (1a), 2,6-iPr2C6H3 (1b)) and [2-(C9H6N)NC(H)C6H4eNAr]NiCl (Ar ¼ 2,6-Me2C6H3
(2a), 2,6-iPr2C6H3 (2b)). All the complexes were fully characterized by NMR and elemental analyses. X-ray
diffraction analyses of 1b and 2b revealed an almost square-planar geometry around the metal center.
When activated with MAO, these nickel complexes can be used as catalysts for the vinyl addition poly-
merization of norbornene affording high molecular weight polymer.
Received 16 July 2013
Received in revised form
10 October 2013
Accepted 12 October 2013
Keywords:
Nickel complex
Anilidoeimine ligand
Norbornene polymerization
Ó 2013 Elsevier B.V. All rights reserved.
1. Introduction
ligands were made and some donor groups were introduced into
the imine moieties forming the tridentate anilidoeimine ligands.
In the past decades, late-transition metal catalysts for olefin
polymerization have attracted considerable attention in both the
academic and industrial fields due to their low electrophilicity and
more heteroatom tolerance [1]. Since the discovery that the bulky
The modified anilidoeimine tridentate ligands have been used to
support various metal complexes. For example, the rare-earth
metal alkyls bearing methoxyl-group decorated anilido-imine tri-
dentate ligands can initiate the polymerization of lactide in single-
site manner. The coordination of the methoxyl group to the metal
center was believed to prevent the back-biting reaction in poly-
merization [16]. Jin group have incorporated the soft sulfur or
phosphine groups into the anilidoeimine ligands and the Ni and Pd
complexes with these tridentate ligands show higher activity to-
ward norbornene polymerization than those with the bidentate
analogs [3f]. Recently we have introduced the quinolinyl group into
the amine moieties giving the quinolinyl anilidoeimine ligands and
the rare-earth-metal complexes [17] and Al (Zn) complexes [18]
bearing such ligands show high activity for ε-caprolactone or lac-
tide polymerization and the polymerization were performed in
living or immortal manner. The coordination of the quinolinyl
group was believed to render the metal center more steric con-
trollabilities and play an important role in the polymerization. In
order to extend the investigation of the anilidoeimine ligands in
supporting the late transition metal complexes for olefin poly-
merization, we also introduce the quinolinyl group into the imino
moieties. Herein we report a series of nickel(II) complexes bearing
tridentate quinolinyl anilido-imino ligands, together with their
catalytic activity for norbornene polymerization.
a-diimine nickel(II) complexes can act as highly active catalysts in
ethylene polymerization [2], a large amount of late-transition metal
complexes were investigated, in which the nickel complexes [3e6]
have drawn great attention for their high activities and good cat-
alytic performance. Various bidentate ligands such as N^N [7], N^P
[8], P^O [9], and N^O [5a,10] and tridentate N^N^N [4bee,11], N^P^N [12]
and N^N^O [13] were tested in supporting the nickel complexes for
olefin polymerization. Recently the anilido-imine ligands, which
feature easy preparation and modification of the steric and elec-
tronic demands, have been widely investigated in supporting rare-
earth metal complexes and early transition metal complexes [14].
Some nickel complexes bearing anilido-imine ligands were inves-
tigated as catalysts for olefin polymerization. The cationic nickel
complexes [15] and nickel(I) complexes [3e] bearing anilidoeimine
ligands show high activity in norbornene polymerization. Intrigued
by these pioneering work, some modification on the anilidoeimine
* Corresponding author. Tel.: þ86 43185168376.
E-mail address: gw@jlu.edu.cn (W. Gao).
0022-328X/$ e see front matter Ó 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.jorganchem.2013.10.020

Z. Hao et al. / Journal of Organometallic Chemistry 749 (2014) 350e355
351
2. Results and discussion
suitable for single crystal X-ray diffraction analysis were grown
from CH2Cl2/hexane mixed solvent. The molecular structure is
depicted in Fig. 1. The nickel atom in 1b is in distorted square planar
environment ligated by the N,N,N ligand and one chlorine atom.
The Nimine atom and Nquinolinyl atom are located in trans position
and the N-aryl ring disposes the vertical position against the parent
plane. The whole molecule is twisted with the dihedral angle be-
tween the quinolinyl ring and the parent ring being 40.70(6)ꢀ.
The nickel atom is almost coplanar with the plane defined by N1,
2.1. Synthesis of the N,N,N-tridentate ligands
The ligands LaH and LbH were synthesized according to the
literature and characterized with 1H NMR and 13C NMR spectroscopy
[17]. The 2-(arylamino)benzaldehyde were prepared by coupling
reactions of the 1,3-dioxolane protected 2-bromobenzaldehyde with
2,6-dimethylaniline or 2,6-diisopropylaniline in toluene using
Pd(OAC)2 as catalysts [18]. The ligands LcH and LdH were prepared by
condensation of the 2-(arylamino)benzaldehyde with 8-amine-
quinoline in hexane in the presence of catalytic amount of formic
acid (Scheme 1). The 1H NMR spectra of LcH and LdH show similar
patterns in low field and the characteristic singlets for HC]N were
found at 8.86e8.87 ppm, which shift to high field with respect to that
in LaH and LbH. Additionally, the singlets of AreNH in LcH and LdH at
11.02e11.10 ppm are slightly shifted to low field compared with
those in LaH and LbH. It is worth to note that, in the high field, LdH
shows two sets of doublets for CH(CH3)2 suggesting that the two
ortho groups are in different environments. This mayattribute to that
the Namino atom is sp2 hybridized and the empty p orbitals interact
ꢀ
N2, N3, Cl1 with the max deviation of 0.0365(8) A. The NieN1 bond
ꢀ
distance of 1.879(2) A is slightly shorter than that of NieN3
ꢀ
ꢀ
(1.906(2) A). While the NieN2 bond distance of 1.930(2) A is much
longer than those in the NieN1 and NieN3, and is also longer than
those in NNP nickel complex [3f].
Complexes 2a and 2b were prepared in a similar procedure to
that for preparation of 1a and 1b as shown in Scheme 3. Treatment of
the ligands (LcH and LdH) with nBuLi at low temperature and sub-
sequent addition of NiCl2(DME) gave complexes 2a and 2b as purple
powder in moderate yields. Complexes 2a and 2b were fully char-
acterized with elemental analysis and NMR spectroscopy. The 1H
NMR spectra of 2a and 2b show similar patterns in aromatic region
and the singlets for HC]N groups are shifted upfield with respect to
that in LcH and LdH. In the aliphatic area the resonances for ortho
groups are shifted slightly to low field when compared to those in
corresponding free ligands. Moreover, in 2b two widely separated
doublets for the CH(CH3)2 were found (Dd ¼ 0.60 ppm). We reasoned
that the coordination of the imino group to the nickel as well as the
repulsions of the bulky ortho groups with the adjacent parent ring
inhibit the free rotations of CeN bond in amino moieties and the
methyls in two isopropyl group are in different environments.
The molecular structure of 2b was determined by X-ray
diffraction analysis (Fig. 2). The unit cell of 2b contains two
crystallographically-independent molecules which possess similar
connectivity. The nickel atoms in 2b were ligated by the N,N,N
tridentated ligand and a chlorine group, and the geometries around
them can be best described as a distorted square planar. It is worth
to note that in one molecule the quinolinyl moiety is essentially
coplanar with the parent phenyl ring with the little dihedral angle
(5.03(9)ꢀ). While in the other molecule the two rings are twisted
slightly with the dihedral angle being 18.46(9)ꢀ. The bond distances
with the
p systems of the attached phenyl ring. The pep interaction
inhibits the free rotations of AreN bonds, leaving the two ortho
isopropyl groups in different chemical environments.
2.2. Synthesis and characterization of the N,N,N-tridentate nickel
complexes
The N,N,N-tridentate nickel complexes 1a and 1b were synthe-
sized via a conventional lithium-salt metathesis reaction. The
lithium salts of LaH and LbH were prepared in-situ by addition of the
nBuLi to the solution of ligands in THF at low temperature. After
stirring at low temperature for 30 min, the NiCl2(DME) was
added in one portion and the resulted mixtures were allowed to
warm to room temperature. Evaporation of the solvent and re-
crystallization the residues with toluene/hexane mixed solvent
afford the nickel complexes 1a and 1b as red powder (Scheme 2).
The nickel complexes were characterized by elemental analyses, 1H
NMR, and 13C NMR spectroscopy. For both complexes, the signals of
eNH disappeared and the singlets resonance for HC]N were
observed at 7.14e7.16 ppm, which were shifted upfield when
compared to those in the free ligands (LaH and LbH). The signals of
ortho substituents in the high field are shifted to low field. In 1b two
separated doublets for the CH(CH3)2 were found (Dd ¼ 0.41 ppm),
which suggested that the methyls in isopropyl groups are in
different chemical environments. As can be seen from the molec-
ular structure of 2b (vide infra), the coordination of imine groups to
the nickel inhibits the free rotation of the N-aryl bond and the two
iPr groups are therefore in different environments. Crystals of 1b
ꢀ
ꢀ
ꢀ
of NieNamino (1.897(3) A and 1.901(3) A), NieNimino (1.937(3) A, and
ꢀ
ꢀ
ꢀ
1.941(3) A), and NieNquinolinyl (1.876(3) A and 1.906(3) A) are all
comparable to those in 1b and those in other anilidoeimino nickel
complexes [3e,3f,15].
2.3. Norbornene polymerization with nickel complexes
The nickel complexes were tested to initiate the norbornene
polymerization. The selective data were summarized in Table 1. The
results showed that, activated with MAO, the nickel complexes
show moderate activities in norbornene polymerization at room
temperature and the activities of 0.68 ꢁ 105e1.06 ꢁ 105 g PNB (mol
of Ni)ꢂ1 hꢂ1 were obtained (entry 1e4). It is worth to note that in
the catalytic system involving 1a and 1b the ortho substituents of
the ligands shows strong influences on the activities. Complex 1b
N
Ar
N
F
N
H
Ar
Ar
NHLi
THF
N
N
LaH, Ar = 2,6-Me2C6H3
LbH, Ar = 2,6-iPr2C6H3
Cl
N
N
N
Ar
N
Ni
H
HN
O
Ar
N
H
Ar
N
nBuLi
NH2
N
N
N
N
1a, Ar = 2,6-Me2C6H3
1b, Ar = 2,6-iPr2C6H3
LcH, Ar = 2,6-Me2C6H3
LdH, Ar = 2,6-iPr2C6H3
NiCl2(DME)
Methanol
Scheme 1. Synthesis route of the N,N,N-tridentate ligands.
Scheme 2. Synthesis route of 1a and 1b.

352
Z. Hao et al. / Journal of Organometallic Chemistry 749 (2014) 350e355
Fig. 1. Perspective view of complex 1b with thermal ellipsoids drawn at 30% proba-
bility level. Uncoordinated solvents and hydrogens are omitted for clarity. The selected
ꢀ
bond lengths (A) and angles (deg.): Ni(1)eN(1) 1.879(2), Ni(1)eN(2) 1.930(2), Ni(1)e
N(3) 1.906(2), Ni(1)eCl(1) 2.187(1), C(1)eN(1) 1.378(2), C(7)eN(3) 1.301(3); N(1)e
Ni(1)eCl(1) 174.96(5), N(3)eNi(1)eN(2) 175.49(7), N(1)eNi(1)eN(3) 92.36(7).
Cl
N
N
Ni
H
Ar
N
Ar
N
nBuLi
N
N
2a, Ar = 2,6-Me2C6H3
2b, Ar = 2,6-iPr2C6H3
NiCl2(DME)
Scheme 3. Synthesis route of the 2a and 2b.
with bulky ortho substituents is more active than 1a under same
conditions. This might be ascribed to the differences in the stabil-
ities of the resulted active species during the polymerization.
Complexes with bulky substituents at the axial position may be
more stable and can survive for long time. Interestingly, complex 2a
and complex 2b show almost the same activities under the same
conditions. It is more possible that in the systems with 2a and 2b
the electronic effects rather than the steric effects play the key roles
in the polymerization. In order to investigated the reaction pa-
rameters affecting the polymerization of norbornene complex 1b
was studied under different reaction conditions such as different
Al/Ni molar ratios, and different temperature. Variations of the ratio
of MAO to 1b show significant effect on catalytic activity and the
molecular-weight of the obtained polymers. As shown in Table 1,
catalytic activity of 1b increased rapidly firstly with increases in Al/
Ni ratios, and then remained steady after the Al/Ni reached about
1500:1. Correspondingly molecular weights of the polymers grad-
ually decrease from 8.61 ꢁ 105 to 0.83 ꢁ 105. This is may ascribe to
the more efficient chain transfer at high Al/Ni ratios. Catalyst ac-
tivity and molecular weights of the resultant polymers were also
dramatically influenced by the polymerization temperature. When
the polymerization temperature increased from 20 ꢀC to 60 ꢀC, the
activities gradually decreased from 3.32 ꢁ 105 g PNB (mol of
Ni)ꢂ1 hꢂ1 to 0.38 ꢁ 105 g PNB (mol of Ni)ꢂ1 hꢂ1. This is perhaps due
the deactivation of the active species at high temperature. The
molecular-weight of the polymer also decreases with the increase
of the polymerization temperature. This may probably due to the
higher chain transfer rates at high temperature. The FT-IR spectra of
the resulted polymer show the characteristic peak of poly-
norbornene in the range of 940 cmꢂ1 to 943 cmꢂ1 which can be
assigned to the vinyl addition polymer. No detectable absorption
peaks at 960 cmꢂ1 was found suggesting that the norbornene
polymerization initiated by the nickel complexes and MAO were
performed in vinyl addition manner [19].
Fig. 2. Perspective view of complex 2b with thermal ellipsoids drawn at 30% proba-
bility level. Hydrogens and uncoordinated solvent are omitted for clarity. The selected
ꢀ
bond lengths (A) and angles (deg.): Ni(1)eN(1) 1.901(3), Ni(1)eN(2) 1.941(3), Ni(1)e
N(3) 1.882(3), Ni(2)eN(4) 1.897(3), Ni(2)eN(5) 1.937(3), Ni(2)eN(6) 1.876(3), Ni(1)e
Cl(1) 2.1965(10), Ni(2)eCl(2) 2.1858(9); N(1)eNi(1)eN(3) 93.81(12), N(3)eNi(1)eCl(1)
167.63(9), N(1)eNi(1)eN(2) 173.58(12), N(4)eNi(2)eN(6) 93.69(12), N(6)eNi(2)eCl(2)
166.62(9), N(4)eNi(2)eN(5) 172.88(12).
Table 1
Addition polymerization of norbornene with nickel complexes activated by meth-
ylaluminoxane (MAO).a
d
Entry Cat Al/Ni M/I
Time, Temp, Yield,b Activityc Mv, ꢁ 105
(min) (ꢀC)
(g)
1
2
3
4
5
6
7
8
1a
1b
2a
2b
1b
1b
1b
1b
1b
1b
1b
1b
1b
1b
500 2000
500 2000
500 2000
500 2000
500 1000
500 1500
500 3000
500 4000
60
60
60
60
60
60
30
90
20
20
20
20
20
20
20
20
20
40
60
20
20
20
0.34
0.53
0.51
0.50
0.26
0.26
0.92
1.28
1.65
0.22
0.18
0.63
0.72
0.73
0.68
1.06
1.01
1.00
0.53
0.53
1.85
2.57
3.32
0.46
0.38
1.27
1.45
1.47
4.79
8.61
15.72
12.17
n.d.
3.63
2.55
8.60
8.28
1.85
0.67
2.37
1.12
0.83
9
500 5000 120
10
11
12
13
14
500 2000
500 2000
1000 2000
1500 2000
2000 2000
60
60
60
60
60
a
Polymerization conditions: toluene 15 mL; catalyst, 5
initiator in mole ratio.
m
mol; M/I ¼ monomer/
b
Isolated yield.
c
In units of 105 g (mol of Ni)ꢂ1 hꢂ1
.
d
Obtained by capillary viscosimetry using the MarkeHouwink coefficients
a ¼ 0.56, K ¼ 7.78 ꢁ 10ꢂ4 dl/g.

Z. Hao et al. / Journal of Organometallic Chemistry 749 (2014) 350e355
353
3. Conclusions
4.4. Synthesis of 2-(8-(C9H6N)NC(H)C6H4eHN(2,6-Me2C6H3))
(LdH)
Four nickel complexes bearing N,N,N-tridentated quinolinyl
anilido-imine ligands have been synthesized and characterized.
The nickel complexes exhibit square planar coordination around
the metal center. When activated with MAO, these nickel com-
plexes show moderate activities in vinyl-addition polymerization of
norbornene.
To a solution of 2-(2,6-diisopropylphenylamino)benzaldehyde
(2.81 g, 10.0 mmol) in hexane (30 mL), quinolin-8-amine (1.60 g,
11.0 mmol) and few drops of formic acid were added. After
refluxing for 12 h, the hexane was removed under reduced pres-
sure. Treatment of the residue with methanol affords the LdH as
yellow powder. Yield 2.72 g (67%). Anal. Calcd for C28H29N3 (%): C,
82.52; H, 7.17; N, 10.31. Found: C, 82.61; H, 7.20; N, 10.28. 1H NMR
4. Experimental section
(300 MHz, CDCl3, 25 ꢀC):
d
1.16 (d, 3J ¼ 6.0 Hz, 6H, CH(CH3)2), 1.22
4.1. General methods
(d, 3J ¼ 9.0 Hz, 6H, CH(CH3)2), 3.29e3.38 (m, 2H, CH(CH3)2), 6.29
(d, 3J ¼ 9.0 Hz, 1H, AreH), 6.69 (m, 1H, AreH), 7.11e7.16 (m, 2H,
AreH), 7.24e7.27 (m, 3H, AreH), 7.35e7.41 (m, 2H, AreH), 7.44e
7.47 (m, 1H, AreH), 7.55 (t, 3J ¼ 9.0 Hz, 1H, AreH), 7.63e7.65 (m,
1H, AreH), 8.13 (d, 3J ¼ 9.0 Hz, 1H, AreH), 8.84e8.86 (m,
3J ¼ 4.1 Hz, J ¼ 1.6 Hz, 1H, AreH), 8.87 (s, 1H, AreCH]N), 11.02 (s,
All manipulations involving air and moisture-sensitive com-
pounds were carried out under an atmosphere of dried and purified
nitrogen using standard Schlenk or dry box techniques. Toluene
and hexane were dried over sodium/benzophenone and distilled
under nitrogen prior to use. Elemental analyses were performed on
a Varian EL microanalyzer. NMR spectra were recorded on a Varian
Mercury-300 NMR spectrometer at room temperature in CDCl3.
2,6-dimethylaniline and 2,6-diisopropylaniline were purchased
from Aldrich.
1H, AreNH). 13C NMR (75 MHz, CDCl3, 25 ꢀC):
d 23.27 (s, 2C,
ArC(CH3)2), 25.02 (s, 2C, ArC(CH3)2), 28.71 (s, 2C, ArC(CH3)2),
112.36, 115.31, 117.43, 118.26, 121.57, 123.87, 124.89, 126.91, 129.25,
132.23, 134.86, 135.42, 135.87, 142.80, 147.90, 149.38, 150.06,
150.38, 164.76 (s, 1C, CH]N) ppm.
4.2. Synthesis of (2-(2,6-dimethylphenylamino)benzaldehyde)
4.5. Synthesis of [2-(2,6-Me2C6H3NC(H)C6H4eNC9H6N)]NiCl (1a)
2,6-Dimethylaniline (3.00 g, 24.8 mmol), Pd(OAc)2 (43.6 mg,
0.194 mmol), NaOtBu (2.86 g, 29.7 mmol), bis[2-(diphenylphos-
phino)phenyl]ether (DPEphos) (160.5 mg, 0.298 mmol), 1,3-
dioxolane protected 2-bromobenzaldehyde (6.27 g, 27.3 mmol)
and degassed toluene (50 mL) were added into a flask. After stirring
at 100 ꢀC for 10 h, water (40 mL) and toluene (100 mL) were added
and the toluene phase was collected. p-TsOH (2.08 g) was added
and the solution was stirred for 2 h and washed with concentrated
aqueous NaHCO3 (30 mL). The organic solution was dried with
anhydrous MgSO4 and the solvent was removed by rotary evapo-
rator to give a residue which was purified by column chromatog-
raphy on silica gel eluting with ethyl acetate and petroleum ether
(v/v, 1:30). Yield (3.91 g, 70%). Anal. Calcd for C15H15NO (%): C,
79.97; H, 6.71; N, 6.22. Found: C, 79.81; H, 6.67; N, 6.28. 1H NMR
A hexane solution of nBuLi (0.66 mL, 1.05 mmol) was added
dropwise to a THF (20 ml) solution of LaH (0.35 g, 1.00 mmol)
at ꢂ78 ꢀC. The mixture was stirred for 1 h and then NiCl2(DME)
(0.22 g, 1.00 mmol) was added. The reaction mixture was allowed
to warm gradually to room temperature and stirred overnight.
The solvent was removed under reduce pressure and the residue
was treated with toluene, after evaporation of the toluene to
dryness, the product was obtained as purple powder. Yield, 0.37 g
(85%). Anal. Calcd for C24H20ClN3Ni (%): C, 64.84; H, 4.53; N, 9.45.
Found: C, 64.75; H, 4.61; N, 9.60. 1H NMR (300 MHz, CDCl3,
25 ꢀC):
d
2.82 (s, 6H, CH3), 6.69 (t, 3J ¼ 6.0 Hz, 1H, AreH), 7.07 (s,
1H, HC]N), 7.12 (d, 3J ¼ 9.0 Hz, 1H AreH), 7.23e7.30 (m, 5H Are
H), 7.40 (t, 3J ¼ 9.0 Hz, 1H, AreH), 7.67 (d, 3J ¼ 9.0 Hz, 1H, AreH),
7.95 (d, 3J ¼ 9.0 Hz, 1H, AreH), 8.17 (d, 3J ¼ 9.0 Hz, 1H, AreH), 8.67
(d, 3J ¼ 6.0 Hz, 1H, AreH). 13C NMR (75 MHz, CDCl3, 25 ꢀC):
(300 MHz, CDCl3, 25 ꢀC):
d
2.19 (s, 6H, CH3), 6.21 (d, 3J ¼ 8.4 Hz, 1H,
AreH), 6.76 (m, 1H, AreH), 7.16 (s, 3H, AreH), 7.29e7.22 (m, 1H, Are
d
20.03 (s, 2C, ArCH3), 116.45, 116.94, 117.41, 118.03, 121.47, 126.13,
H), 7.56 (dd, 3J ¼ 7.8 Hz, J ¼ 1.6 Hz, 1H, AreH), 9.55 (s, 1H, AreCHO),
128.01, 128.23, 133.68, 134.07, 138.66, 151.36, 164.37 (s, 1C, CH]N)
ppm.
9.96 (s, 1H, AreNH). 13C NMR (75 MHz, CDCl3, 25 ꢀC):
d 18.3 (s, 2C,
ArCH3), 116.0, 118.4, 112.3, 127.0, 128.6, 135.8, 136.4, 136.7, 149.6,
194.3 (s, 1C, CH]N) ppm.
4.6. Synthesis of [2-(2,6-iPr2C6H3NC(H)C6H4eNC9H6N)]NiCl (1b)
4.3. Synthesis of 2-(8-(C9H6N)NC(H)C6H4eHN(2,6-Me2C6H3))
(LcH)
Complex 1b was synthesized in the same procedure as that for
1a with LbH (0.41 g, 1.00 mmol) and NiCl2(DME) (0.22 g,
1.00 mmol) as starting materials or reagents. Pure 1b was obtained
as purple powder. Yield: 0.44 g (88%). Single crystals for X-ray
diffraction analysis were obtained from hexane/THF mixed solu-
tion. Anal. Calcd for C28H28ClN3Ni (%): C, 67.17; H, 5.64; N, 8.39.
Found: C, 67.25; H, 5.60; N, 8.48. 1H NMR (300 MHz, CDCl3, 25 ꢀC):
To a solution of 2-(2,6-dimethylphenylamino)benzaldehyde
(2.25 g, 10.0 mmol) in hexane (30 mL) quinolin-8-amine (1.6 g,
11.0 mmol) and few drops of formic acid were added. After
refluxing for 12 h, the resulted mixture was evaporated to dryness.
Treatment of the residue with methanol affords the LcH as yellow
powder. Yield 2.28 g (65%). Anal. Calcd for C24H21N3 (%): C, 82.02; H,
6.02; N, 11.96. Found: C, 82.12; H, 6.07; N, 11.91. 1H NMR (300 MHz,
d
1.17 (d, JHeH ¼ 6.0 Hz, 6H, CH(CH3)2), 1.59 (d, 3J ¼ 6.0 Hz, 6H,
CH(CH3)2), 4.27 (sept, 3J
¼
6.0 Hz, 2H, CH(CH3)2), 6.69 (t,
CDCl3, 25 ꢀC):
d
2.36 (s, 6H, CH3), 6.33 (d, 3J ¼ 6.0 Hz,1H, AreH), 6.72
3J ¼ 6.0 Hz, 1H, AreH), 7.11 (s, 1H, HC]N), 7.12 (d, 3J ¼ 9.0 Hz, 1H
AreH), 7.23e7.30 (m, 5H AreH), 7.41 (t, 3J ¼ 9.0 Hz, 1H, AreH),
7.69 (d, 3J ¼ 9.0 Hz, 1H, AreH), 7.96 (d, 3J ¼ 9.0 Hz, 1H, AreH), 8.16
(d, 3J ¼ 9.0 Hz, 1H, AreH), 8.69 (d, 3J ¼ 6.0 Hz, 1H, AreH). 13C NMR
(m, 1H, AreH), 7.07e7.20 (m, 4H, AreH), 7.37e7.41 (m, 2H, AreH),
7.45e7.48 (m, 1H, AreH), 7.54 (t, 3J ¼ 9.0 Hz, 1H, AreH), 7.62e7.65
(m,1H, AreH), 8.13 (dd, 3J ¼ 9.0 Hz, J ¼ 1.7 Hz,1H, AreH), 8.86 (s,1H,
AreCH]N), 8.88 (dd, 3J ¼ 4.1 Hz, J ¼ 1.6 Hz, 1H, AreH), 11.10 (s, 1H,
(75 MHz, CDCl3, 25 ꢀC):
d 23.89 (s, 2C, ArCH(CH3)2), 24.79 (s, 2C,
AreNH). 13C NMR (75 MHz, CDCl3, 25 ꢀC):
d
18.77 (s, 2C, ArCH3),
ArCH(CH3)2), 29.31 (s, 2C, ArCH(CH3)2), 116.41, 116.91, 117.43,
117.08, 121.47, 123.37, 123.91, 126.84, 128.18, 129.17, 133.63, 134.11,
138.58, 141.51, 145.58, 148.07, 149.32, 149.38, 151.51, 164.32 (s, 1C,
CH]N) ppm.
112.17, 115.64, 117.88, 118.17, 121.59, 125.00, 126.17, 128.45, 129.24,
132.36, 134.97, 135.92, 136.78, 138.25, 142.85, 148.62, 149.19, 150.08,
164.57 (s, 1C, CH]N) ppm.

354
Z. Hao et al. / Journal of Organometallic Chemistry 749 (2014) 350e355
4.7. Synthesis of [2-(8-(C9H6N)NC(H)C6H4eN(2,6-Me2C6H3))]NiCl
(2a)
4.10.1. Crystal data for 1b
31H35ClN3Ni, M ¼ 543.78, monoclinic, P21/n, a ¼ 14.2122(9),
C
¼
109.9600(10)ꢀ,
ꢀ
b
13.7132(9),
c
¼
15.0734(10) A,
b
¼
3
V ¼ 2761.3(3) A , Z ¼ 4, Dcalc ¼ 1.308 g cmꢂ3, 16,720 measured in-
ꢀ
Complex 2a was synthesized in the same manner as 1a with LcH
(0.35 g, 1.00 mmol) and NiCl2(DME) (0.22 g, 1.00 mmol) as starting
materials or reagents. Pure 2a was obtained as purple powder.
Yield: 0.35 g (79%). Anal. Calcd for C24H20ClN3Ni (%): C, 64.84; H,
4.53; N, 9.45. Found: C, 64.97; H, 4.66; N, 9.51. 1H NMR (300 MHz,
tensities (1.70ꢀ
ꢃ
q
ꢃ 26.05ꢀ), 5442 independent (Rint ¼ 0.0277)
diffraction data, R ¼ 0.0349, wR ¼ 0.0820 for data (I ꢄ 2
s(I)),
Rall ¼ 0.0457, wRall ¼ 0.0875 for all data. CCDC (949273).
CDCl3, 25 ꢀC):
d
2.55 (s, 6H, CH3), 6.04 (d, 3J ¼ 9.0 Hz,1H, AreH), 6.34
4.10.2. Crystal data for 2b
(t, 3J ¼ 6.0 Hz, 1H, AreH), 6.80 (m, 1H, Ar-H), 7.00e7.09 (m, 3H, Ar-
H), 7.26 (dd, 3J ¼ 6.0 Hz, J ¼ 1.6 Hz,1H, AreH), 7.35e7.40 (m, 1H, Are
H), 7.54e7.62 (m, 2H, AreH), 7.84 (dd, 3J ¼ 6.0 Hz, J ¼ 1.2 Hz,1H, Are
H), 8.14 (s, 1H, AreCH]N), 8.20 (dd, 3J ¼ 6.0 Hz, J ¼ 1.1 Hz, 1H, Are
H), 9.19 (dd, 3J ¼ 6.0 Hz, J ¼ 1.2 Hz, 1H, AreH). 13C NMR (75 MHz,
C
28.5H29Cl1.5N3Ni, M ¼ 522.43, triclinic, P-1, a ¼ 10.8383(5),
ꢀ
b ¼ 14.2146(7), c ¼ 17.0475(8) A,
a
¼ 103.3220(10)ꢀ,
b
¼ 97.7830(10)ꢀ,
3
ꢀ
g
¼ 100.4710(10), V ¼ 2469.6(2) A , Z ¼ 4, Dcalc ¼ 0.971 g cmꢂ3,14,613
measured intensities (1.51ꢀ
ꢃ
q
ꢃ 26.05ꢀ), 9492 independent
(Rint ¼ 0.0166) diffraction data, R ¼ 0.0525, wR ¼ 0.1341 for data
CDCl3, 25 ꢀC):
d
19.46 (s, 2C, CH3), 114.63, 114.69, 118.31, 118.80,
(I ꢄ 2 (I)), Rall ¼ 0.0653, wRall ¼ 0.1431 for all data. CCDC (949274).
s
122.69, 123.86, 124.72, 127.99, 128.42, 134.21, 134.28, 134.60, 138.30,
143.25, 147.32, 151.03, 152.66, 154.26 ppm.
Acknowledgments
4.8. Synthesis of [2-(8-(C9H6N)NC(H)C6H4eN(2,6-iPr2C6H3))]NiCl
(2b)
This work was supported by the National Natural Science
Foundation of China (No. 21074043)
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