Synthesis, characterization and catalytic behaviors of water-soluble phosphine-sulfonato nickel methyl complexes bearing PEG-amine labile ligand

Article abstract of DOI:10.1016/j.jorganchem.2009.12.024

Two novel water-soluble phosphine-sulfonato nickel (II) methyl complexes [(P^O)NiMeL] (P^O = κ²-P,O-2-(2-MeO-C₆H₄)₂PC₆H₄SO₃, L = H₂N(CH₂CH₂O)

Full text of DOI:10.1016/j.jorganchem.2009.12.024

Journal of Organometallic Chemistry 695 (2010) 903–908
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Note
Synthesis, characterization and catalytic behaviors of water-soluble
phosphine-sulfonato nickel methyl complexes bearing PEG-amine labile ligand
*
Dao Zhang , Jinyang Wang, Qin Yue
Department of Chemistry, Fudan University, Handan Road 220, Shanghai 100433, PR China
a r t i c l e i n f o
a b s t r a c t
Two novel water-soluble phosphine-sulfonato nickel (II) methyl complexes [(P^O)NiMeL] (P^O = j
2-P,O-
2-(2-MeO-C6H4)2PC6H4SO3, L = H2N(CH2CH2O)nMe, n = ca. 52, 2a; n = ca. 16, 2b) have been prepared and
characterized by 1H, 31P NMR and elemental analysis, and their reactivity towards ethylene was studied.
Ó 2009 Elsevier B.V. All rights reserved.
Article history:
Received 2 December 2009
Received in revised form 22 December 2009
Accepted 25 December 2009
Available online 4 January 2010
Keywords:
Nickel
Phosphine-sulfonato
Organometallic catalysts
1. Introduction
Pyr)] [35] have been synthesized and their catalytic behaviors in
toluene and other organic media have also been carefully
Olefin polymerization by d8 metal complexes has been studied
intensely [1–7]. These late transition metal complexes are much
more tolerant towards polar reagents in general by comparison
to their highly oxophilic early transition metal counterparts. Thus,
they can react with olefins to form polyethylene or copolymer with
electron-deficient vinyl monomers such as acrylates [8–11]. In
some cases polymerizations reaction can be carried out in aqueous
systems to afford dispersions of submicron particles [12,13]. The
water-soluble catalytic precursors, for example, Ni(II) salicylaldim-
inato complexes [(N^O)NiMe(L)], could afford nanoparticles with
sizes of only ca. 10–30 nm – a size range which is challenging to
access by any given polymerization type [14,15]. Such particles
can be served as crystalline mesoscopic building blocks for ultra-
thin films [16–18].
investigated.
Previously we have prepared several water-soluble PEG-amine
Pd(II) phosphine-sulfonato methyl complexes [(j
2-[P^O])PdMe(L)]
(L = tri(sodiumphenylsulfonate) phosphine; NH2(CH2CH2O)nMe,
n = ca. 52), and showed that their aqueous solutions could poly-
merize ethylene to ca. 20 nm particles of low molecular weight lin-
ear polyethylene [36]. Herein we wish to report the hydrophilic
phosphine-sulfonato nickel(II) methyl complexes [(j
2-[P^O])Ni-
Me(L)] (Scheme 2) comprising PEG-amine labile groups, and their
reactivities towards ethylene and catalytic properties in aqueous
media and non-aqueous systems were also investigated.
2. Results and discussion
In 2002 Drent et al. described for the first time the use of che-
lating SHOP-type phosphine-sulfonato ligand [P^O]ꢀ (Scheme 1)
to stabilize Pd(II) catalytic system that could generate linear
copolymers by random incorporation of ethylene and a variety of
acrylates monomers [19]. This seminal report brings a series of
successful incorporations of polar comonomers in linear copoly-
mer chains [20–32]. Compared with increasing reports of palla-
dium complexes, little attention has been focused on the
corresponding nickel complexes with sulfonato phosphine ligands
Reactions of {[(j
2-[P,O])NiMe)]2(NMe2CH2CH2NMe2)} (1) [22]
with 1.0 equiv. of H2N(CH2CH2O)nMe (n = ca. 52 or 16) (for short,
PEG-amine) in DMF afforded the corresponding hydrophilic nickel
complexes 2a and 2b (Scheme 1). Both 2a and 2b are soluble in de-
gassed water (solubility > 100 lmol/L) and stable in the solid state
under inert atmosphere at room temperature. The identity and
purity of these complexes were unambiguously established by
NMR and elemental analysis. The ambient-temperature 1H NMR
spectra of PEG-amine complexes 2a and 2b contain one doublet
for the Ni–CH3 hydrogens (3JPH = 6.8 Hz) resonance. The 31P NMR
spectra contain two singlets at d 14.55 for 2a and 14.58 ppm for
2b, respectively (Fig. 1).
[33–35]. Several lipophilic neutral nickel [(
j
2-[P^O])NiPh(PPh3)]
2-[P^O])NiMe(-
[33], {[(
j
2-[P^O])NiMe]2(TMEDA)}(1) [35], and [(
j
Rieger et al. have showed that nickel phenyl complex [(j2
[P^O])NiPh(PPh3)] could be used in an emulsion polymerization
-
* Corresponding author. Tel.: +86 21 65642318; fax: +86 21 65641470.
E-mail address: daozhang@fudan.edu.cn (D. Zhang).
0022-328X/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2009.12.024

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D. Zhang et al. / Journal of Organometallic Chemistry 695 (2010) 903–908
Table 1 summaries the 1H and 31P NMR data of reported nickel
and palladium complexes with phosphine-sulfonato ligand [P^O].
In the whole, the chemical shifts of Ni–CH3 are located at lower
field region of about 1.0 ppm than those of Pd–CH3. In 31P NMR
spectra, the same shift tendency of phosphine signals (no less
5.0 ppm) and bigger coupling constant (ca. 290 vs. 405) were
observed.
Ethylene polymerizations employing the water-soluble nickel
complexes 2a and 2b in neat water have been carefully tested.
Unfortunately, both of them are inactive towards ethylene under
this condition. The same result was also obtained for hydrophilic
complexes 2a and 2b and lipophilic complex 3 using an emulsion
process in CH2Cl2/H2O solution or in the presence of cocatalyst
Ni(COD)2.
Scheme 1. The phosphine-sulfonato fragment.
to afford a latex of low molecular weight polyethylene in a very
low yield [33]. A similar palladium methyl complex [(
2-[P^O])Pd-
j
Me(PPh3)] has also been prepared by Jordan and co-workers [25].
For further understanding of the loss of activity of this kind of
organonickel catalysts in water, the reactivity of complex 2a to-
wards water was studied by NMR spectroscopy (Fig. 3). Firstly,
the 1H NMR spectrum of 2a in neat DMSO-d6 solution showed no
obvious change even after the solution was heated to 70 °C. Sec-
ondly, the similar 1H NMR study indicates that 2a is stable in
DMSO-d6/D2O (v/v: 2/1) solution. The Ni–Me signal coalesces with
each other to a broader peak at 70 °C, which may be a simple
dynamics of 2a. Thirdly, the DMSO-d6/D2O (v/v: 2/1) solution of
2a is stable at room temperature upon addition of ethylene to
For comparison, nickel methyl complex [(
(3) was synthesized. In the NMR spectra of 3, a JPH (10 Hz) triplet
j
2-[P^O])NiMe(PPh3)]
3
2
resonance at ꢀ1.24 ppm for the methyl group, and a large JPP va-
lue (292 Hz) with two doubles at d 25.16 and 2.17 ppm are ob-
served, consistent with a cis arrangement of the methyl and the
phosphine group (Fig. 2). The similar 31P resonances and coupling
2
constant JPP have been achieved for [(
j
2-[P^O])NiPh(PPh3)]
2
(d = 18.1(d), 3.02(d), JPP = 285.0 Hz) [33] and [(
j
2-[P^O])NiPh
2
(PPh3)] (d = 27.3(d), 7.90(d), JPP = 403 Hz) [25].
Scheme 2. Synthesis of the hydrophilic phosphine-sulfonato nickel methyl complexes.
Fig. 1. The 1H NMR spectra (right), and 31P (left) NMR spectra of CD2Cl2 solution of 2a acquired at 25 °C. The asterisk presents the 1H chemical shift signal of residual
undeuterated CD2Cl2 solvent.

D. Zhang et al. / Journal of Organometallic Chemistry 695 (2010) 903–908
905
Fig. 2. The 1H NMR spectra (right), and 31P (left) NMR spectra of CD2Cl2 solution of 3 acquired at 25 °C. The asterisk presents the 1H chemical shift signal of residual
undeuterated CD2Cl2 solvent.
Table 1
Selected 1H and 31P NMR data of some phosphine-sulfonato nickel and palladium complexes.
Compound
1H NMR d [ppm] [MꢀCH3] (M = Ni, Pd)
31P NMR d [ppm]
Reference
3
{(j
{(j
{(j
{(j
{(j
{(j
{(j
{(j
2-[P,O])NiMe(Pyr)}
ꢀ0.99 (d, JPH = 7.2 Hz)
16.22 (s)
14.55 (s)
[35]
2-[P,O])NiMe(NH2(CH2CH2O)nMe)} (n ꢂ 52) (2a)
2-[P,O])NiMe(NH2(CH2CH2O)nMe)} (n ꢂ 16) (2b)
2-[P,O])NiMe(PPh3)} (3)
ꢀ1.17 (d, JPH = 6.8 Hz)
This work
This work
This work
[33]
[22]
[36]
3
3
ꢀ1.17 (d, JPH = 6.8 Hz)
14.58 (s)
3
2
2
ꢀ1.24 (t, JPH = 10 Hz)
25.16 (d, JPP = 292 Hz), 2.17 (d, JPP = 292 Hz)
2-[P,O])Ni(Ph)(PPh3)}
–
18.10 (d, JPP = 285 Hz), ꢀ3.02 (d, JPP = 285 Hz)
2
2
2-[P,O])PdMe(Pyr)}
0.24 (s)
0.04 (d, JPH = 2.8 Hz)
ꢀ0.12 (t, JPH = 6.0 Hz)
21.54 (s)
19.18 (s)
2-[P,O])PdMe(NH2(CH2CH2O)nMe)} (n ꢂ 52)
3
2-[P,O])PdMe(PPh3)}
27.3 (d, JPP = 403 Hz), 7.90 (d, 2JPP = 403 Hz)
[25]
3
2
NMR conditions: 25 °C; C2D2Cl2, 1H: 400 MHz, 31P: 161.8 MHz.
Fig. 3. High field region of 1H NMR region of the Ni–Me signals of compound 2a in DMSO-d6 (left) and DMSO-d6/D2O (v/v: 2/1) with (right) or without ethylene (middle) at
25 °C and 70 °C. 1H chemical shifts referenced to residual undeuterated DMSO solvent signal (d 2.54 ppm).
the NMR tubes, which can be seen from its doublet signal of Ni–
Me. Finally, when the above DMSO-d6/D2O solution of 2a was
heated to high-temperature in the presence of ethylene, Ni–Me
signal disappeared quickly, which means that ethylene plays a role
for the loss of activity of such neutral phosphine-sulfonato nickel
methyl catalysts [37]. Moreover, unlike phosphine-sulfonato palla-
dium methyl complexes, no nickel metal could be observed after
NMR determinations at high-temperature in presence of 1 atm of
ethylene [36].
the ethylene polymerization in non-aqueous toluene. Preliminary
ethylene polymerization reactions were performed to find that un-
like phenyl nickel complexes, these methyl nickel complexes
showed high activities without B(C6F5)3 or Ni(COD)2 as scavengers.
These nickel catalysts polymerize ethylene in toluene at 70 °C with
activity over the TON range of 29 000–346 000 mol [C2H4] ꢁ molꢀ1
[Ni] hꢀ1. Ethylene polymerization results in toluene are summa-
rized in Table 2.
The polymers have the similar chain structures to those pro-
duced by previously reported phosphine-sulfonato nickel cata-
lysts but are slightly different from those obtained by
Given that these phosphine-sulfonato nickel methyl complexes
were inactive toward ethylene in aqueous media, we undertook

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D. Zhang et al. / Journal of Organometallic Chemistry 695 (2010) 903–908
Table 2
Ethylene polymerization using nickel catalysts 1–3.a
TONb
Mn
Internal unsat. (%)c
Me branches per 1000 Cd
c
Entry
Catalyst
Time (min)
Yield (g)
1
2
3
4
1
15
30
15
15
5.85
4.69
2.03
24.22
83 600
33 500
29 000
346 000
1196
1154
1140
980
45
47
48
48
12
14
13
13
2a
2b
3
a
b
c
Polymerization conditions: 10 lmol of [Ni], 40 bar of C2H4, 100 mL of toluene, 70 °C.
Mol [C2H4] ꢁ molꢀ1 [Ni] h ꢀ1
.
Determined by 1H NMR assuming that one double bond per chain.
d
Determined by 13C NMR at 115 °C in C2D2Cl4.
Fig. 4. The selected 1H NMR (the above) and 13C (the below) spectrum regions of polyethylene produced by nickel catalyst 2a (Table 2, entry 2). The chemical shift is in units
of d. NMR conditions: 115 °C in CDCl2CDCl2.
palladium catalysts. Although these nickel complexes produce
linear polyethylene with low levels of 10–14 methyl branches,
ethyl and longer branches were observed from high-temperature
13C NMR (Fig. 4). The 1H NMR spectra of the polyethylenes con-
tain resonances for internal double bonds chains (PCH@CHP0) be-
sides terminal end group olefins (PCH@CH2) (P and P0 represent
polymer chain, Fig. 4). The mole ratio of internal-olefins and ter-
minal-olefins seems a constant (near 1:1) although these nickel
complexes have different labile ligands, such as tmeda (1), amine
(2a, 2b) and phosphine (3). Moreover, the polyethylenes obtained
with these nickel complexes have number average molecular
weight (Mn’s) between 980 and 1420 which is much lower than
polyethylene from other neutral nickel catalyst systems [38]. An-
other easily concluded point is that the labile ligand of nickel
complexes has an influence to its catalytic activity. For example,
complex 3 with a more labile phosphine-containing ligand, re-
veals a much higher activity than complexes 2a and 2b with
nitrogen-containing ligands NH2(CH2CH2O)nMe (Table 2, entry 4
vs. entries 2 and 3).
3. Conclusions
The coordination of hydrophilic poly(ethylene glycol)-substi-
tuted amine to the (j
2-P,O-phosphine-sulfonato)NiMe fragment
affords stable water-soluble complexes, which were isolated in
high yield and fully characterized by NMR spectroscopy. These
water-soluble neutral methyl nickel catalysts are stable in neat
water, but revealed a rapid deactivation in the presence of ethyl-
ene. In spite of that these nickel complexes could efficiently cata-
lyze ethylene polymerization to yield low molecular weight
polyethylene.

D. Zhang et al. / Journal of Organometallic Chemistry 695 (2010) 903–908
907
glove box and stirred for 1 h. The volatiles were carefully removed
under vacuum. The resulting solid was triturated with diethyl
ether (ca. 5 mL), washed twice with ether, and dried under vacuum
overnight to afford a yellow solid in 87% yield. 1H NMR (400 MHz,
4. Experimental
4.1. Materials and instrumentation
3
CD2Cl2): d ꢀ1.24 (t, JPH = 10, 3H, Ni–Me), 3.74 (s, 6H, ArOMe),.
Unless noted otherwise, all manipulations of metal complexes
were carried outunderan inertatmosphere using standardglovebox
or Schlenk techniques. Toluene and diethyl ether were distilled from
sodium/benzophenone, and methylene chloride and DMF from CaH2
under argon. Chemicals, H2N(CH2CH2O)nMe (n = ca. 52, 16),
and [(TMEDA)NiMe2] (TMEDA = N,N,N0,N0-tetramethylethylenedi-
amine) were purchased commercially and used as received. The
phosphine-sulfonic acids ligand [P^O]H was synthesized by modi-
fied multi-step literature routes developed by Drent et al. and Jordan
6.99–7.02 (m, 4H), 7.19 (dd, JHH = 8, JPH = 1, 1H), 7.27 (t, JHH = 8,
1H), 7.47–7.38 (m, 10H), 7.49–7.58 (m, 4H), 7.76 (t, JHH = 8, 6H),
7.83 (dd, JHH = 8, JPH = 6, 1H). 31P{1H} NMR (162 MHz, CD2Cl2): d
25.16 (d, JPP = 292 Hz), 2.17 (d, JPP = 292 Hz, PPh3). Anal. Calc. for
C39H36NiO5P2S (M = 737.41 g molꢀ1): C, 63.52; H, 4.92. Found: C,
63.41; H, 4.77%.
4.4. Ethylene polymerizations
and co-workers [19,24–26,39–42]. Preparation of complexes {[(j2
-
[P,O])NiMe)]2(NMe2CH2CH2NMe2)} (1) was accomplished by reac-
tion of the respective H[PO] with 1 equiv. of [(TMEDA)NiMe2] in
THF under an inert atmosphere in 81% yield [36].
The typical process for ethylene polymerizations of water-solu-
ble complexes 2a and 2b in neat water, see Ref. [36].
The typical process for ethylene polymerizations of 2a, 2b and 3
of in emulsion process (CH2Cl2/H2O), see Ref. [36].
The typical process for non-aqueous ethylene polymerizations
of 2a, 2b and 3 of in toluene, see Ref. [36].
NMR spectra were recorded on a Varian Unity INOVA 400 spec-
trometer. Chemical shifts were referenced to the residual 1H, and
13C solvent resonances, and to external 85% H3PO4 31P), respec-
(
tively. Elemental analyses were performed up to 950 °C on an Ele-
mentar Vario EL. For high-temperature NMR spectroscopy of
polyethylenes, a mixture of polymer and CDCl2CDCl2 in an NMR
tube was heated to 115 °C, affording a homogeneous solution.
The tube was inserted into a preheated NMR probe at 115 °C,
and NMR spectra were obtained after a 5 min temperature equili-
bration period. Methyl branches were quantified from 13C NMR
spectra according to [43,44].
4.5. Variable temperature NMR experiments
Young-J NMR tubes were charged with solid complexes in a
glove box. Generally, 10 mg of 2a were dissolved in 500 lL of sol-
vent. The tube was sealed, taken out of the box, and inserted into a
preheated NMR probe at the desired temperature. NMR spectra
were obtained after a 5 min temperature equilibration period.
For NMR experiments with ethylene, the Young-J NMR tube was
charged with the solid complex and solvent in the glove box, and
closed. The tube was removed from the box, and connected with
a three way stopcock to the Schlenk line, and to the ethylene gas
supply. The tube was cooled to ꢀ78 °C in a dry ice/isopropanol
bath, and charged with ca. 1 atm of ethylene by several pump-fill
cycles. The NMR tubes was sealed, warmed to room temperature,
and shaken briefly prior to recording NMR spectra. For NMR exper-
iments at elevated temperature, the tube was inserted into a pre-
heated NMR probe at the desired temperature and NMR spectra
were obtained after a 5 min temperature equilibration period.
4.2. Synthesis of water-soluble phosphine-sulfonato nickel methyl
complexes 2a and 2b
Complex 1 (0.05 mmol) and PEG-amine (0.10 mmol) of were
dissolved in 3 mL of dry dimethylformamide (DMF) in a glove
box and stirred for 1 h. The volatiles were carefully removed under
vacuum. The resulting solid was triturated with diethyl ether (ca.
5 mL), washed twice with ether, and dried under vacuum over-
night to afford complex water-soluble phosphine-sulfonato nickel
methyl complexes.
{(
j
2-[P,O])NiMe(NH2(CH2CH2O)nMe)} (n ꢂ 52) (2a) was ob-
tained as a yellow solid in 83% yield. 1H NMR (400 MHz, 25 °C,
CD2Cl2): d ꢀ1.17 (d, JHP = 6.8 Hz, 3H, Ni–CH3), 2.19 (t, JHH = 7, 2H,
NH2), 2.99 (br s, 2H,CH2CH2NH2), 3.08 (br s, 2H, CH2CH2–NH2),
3.32 (s, 3H, CH2CH2OCH3), 3.40–3.59 (m, (CH2CH2)n and OCH3),
3.73 (m, 4H, CH2CH2OCH3), 6.95–7.01 (m, 5H), 7.15 (dd, JHH = 8,
JPH = 1, 1H), 7.24 (t, JHH = 8, 1H), 7.42 (m, 1H), 7.50 (t, JHH = 8, 2H),
7.64(m, 2H), 7.90 (dd, JHH = 8, JPH = 6, 1H). 31P{1H} NMR
(162 MHz, 25 °C, CD2Cl2): d 14.55 (s). Anal. Calc. for C126H234
NNiO57PS (M = 2796.91 g molꢀ1): C, 54.11; H, 8.43; N, 0.50. Found:
C, 54.01; H, 8.37; N, 0.54%.
Acknowledgements
This work was financially supported by the Fudan University/
University of Konstanz Program (D.Z.), National Natural Science
Foundation of China, Grant Nos. 20671021 and 20972031, SRF for
ROCS, and Shanghai Leading Academic Discipline Project, Project
No. B108. The authors also thank Prof. Dr. Stefan Mecking in Kon-
stanz University for his kind discussions about aqueous olefins
polymerization.
{(j
2-[P,O])NiMe(NH2(CH2CH2O)nMe)} (n = ca. 16) (2b) was ob-
References
tained as yellow oil in 74% yield. 1H NMR (400 MHz, 25 °C, CD2Cl2):
d ꢀ1.17 (d, JHP = 6.8 Hz, 3H, Ni–CH3), 2.19 (t, JHH = 7, 2H, NH2), 2.99
(br s, 2H,CH2CH2NH2), 3.09 (br s, 2H, CH2CH2–NH2), 3.32 (s, 3H,
CH2CH2OCH3), 3.40–3.58 (m, (CH2CH2)n and OCH3), 3.73 (m, 4H,
CH2CH2OCH3), 6.95–7.01 (m, 5H), 7.15 (dd, JHH = 8, JPH = 1, 1H),
7.24 (t, JHH = 8, 1H), 7.42 (m, 1H), 7.50 (t, JHH = 8, 2H), 7.64(m, 2H),
7.89 (dd, JHH = 8, JPH = 6, 1H). 31P{1H} NMR (162 MHz, 25 °C, CD2Cl2):
d 14.58 (s). Anal. Calc. for C54H90NNiO21PS (M = 1211.02 g molꢀ1): C,
53.56; H, 7.49; N, 1.16. Found: C, 53.29; H, 7.58; N, 1.22%.
[1] S.D. Ittel, L.K. Johnson, M. Brookhart, Chem. Rev. 100 (2000) 1169–1203.
[2] V.C. Gibson, S.K. Spitzmesser, Chem. Rev. 103 (2003) 283–316.
[3] S. Mecking, Coord. Chem. Rev. 203 (2000) 325–351.
[4] S. Mecking, Angew. Chem., Int. Ed. 40 (2001) 534–540.
[5] Z. Guan, Chem. Eur. J. 8 (2002) 3086–3092.
[6] G.J. Domski, J.M. Rose, G.W. Coates, A.D. Bolig, M. Brookhart, Prog. Polym. Sci.
32 (2007) 30–92.
[7] A. Berkefeld, S. Mecking, Angew. Chem., Int. Ed. 47 (2008) 2538–2542.
[8] L.K. Johnson, S. Mecking, M. Brookhart, J. Am. Chem. Soc. 118 (1996) 267–268.
[9] S. Mecking, L.K. Johnson, L. Wang, M. Brookhart, J. Am. Chem. Soc. 120 (1998)
888–899.
[10] L. Johnson, L. Wang, S. McLain, A. Bennett, K. Dobbs, E. Hauptman, A. Ionkin, S.
Ittel, K. Kunitsky, W. Marshall, E. McCord, C. Radzewich, A. Rinehart, K.J.
Sweetman, Y. Wang, Z. Yin, M. Brookhart, ACS Symp. Ser. 857 (2003) 131–142.
[11] C.S. Popeney, D.H. Camacho, Z. Guan, J. Am. Chem. Soc. 129 (2007) 10062–
10063.
4.3. Synthesis of {(j
2-[P,O])NiMe(PPh3)} (3)
Complex
2 (0.053 g, 0.05 mmol) and triphenylphosphine
(0.026 g, 0.10 mmol) of were dissolved in 3 mL of dry DMF in a
[12] F.M. Bauers, S. Mecking, Angew. Chem., Int. Ed. 40 (2001) 3020–3022.

908
D. Zhang et al. / Journal of Organometallic Chemistry 695 (2010) 903–908
[13] R. Soula, C. Novat, A. Tomov, R. Spitz, J. Claverie, X. Drujon, J. Malinge, T.
Saudemont, Macromolecules 34 (2001) 2022–2026.
[14] I. Göttker-Schnetmann, B. Korthals, S. Mecking, J. Am. Chem. Soc. 128 (2006)
7708–7709.
[15] B. Korthals, I. Göttker-Schnetmann, S. Mecking, Organometallics 26 (2007)
1311–1316.
[29] S. Borkar, D.K. Newsham, A. Sen, Organometallics 27 (2008) 3331–3334.
[30] T. Kochi, S. Noda, K. Yoshimura, K. Nozaki, J. Am. Chem. Soc. 129 (2007) 8948–
8949.
[31] T. Kochi, K. Yoshimura, K. Nozaki, Dalton Trans. (2006) 25–27.
[32] D. Guironnet, P. Roesle, T. Rünzi, I. Göttker-Schnetmann, S. Mecking, J. Am.
Chem. Soc. 131 (2009) 422–423.
[16] C.H.M. Weber, A. Chiche, G. Krausch, S. Rosenfeldt, M. Ballauf, L. Harnau, I.
Göttker-Schnetmann, Q. Tong, S. Mecking, Nano Lett. 7 (2007) 2024–2029.
[17] Q. Tong, M. Krumova, S. Mecking, Angew. Chem., Int. Ed. 47 (2008) 4509–4511.
[18] Q. Tong, M. Krumova, I. Göttker-Schnetmann, S. Mecking, Langmuir 24 (2008)
2341–2347.
[33] R.J. Nowack, A.K. Hearley, B. Rieger, Z. Anorg. Allg. Chem. 631 (2005) 2775–
2781.
[34] A.K. Hearley, R.J. Nowack, B. Rieger, Organometallics 24 (2005) 2755–2760.
}
[35] D. Guironnet, T. Runzi, I. Göttker-Schnetmann, S. Mecking, Chem. Commun.
(2008) 4965–4967.
[19] E. Drent, R.v. Dijk, R.v. Ginkel, B.v. Oort, R.I. Pugh, Chem. Commun. (2002) 744–
745.
[36] D. Zhang, D. Guironnet, I. Göttker-Schnetmann, S. Mecking, Organometallics
28 (2009) 4072–4078.
[20] K.M. Skupov, P.M. Marella, J.L. Hobbs, L.H. McIntosh, B.L. Goodall, J.P. Claverie,
Macromolecules 39 (2006) 4279–4281.
[37] I.H. Hristov, R.L. DeKock, G.D.W. Anderson, I. Göttker-Schnetmann, S. Mecking,
T. Ziegler, Inorg. Chem. 44 (2005) 7806–7818.
[21] J.P. Claverie, B.L. Goodall, K.M. Skupov, P.R. Marella, J. Hobbs, Polym. Prepr. 48
(2007) 191–192.
[38] For example, neutral salicylaldiminato nickel catalyst, see: T.R. Younkin, E.F.
Connor, J.I. Henderson, S.K. Friedrich, R.H. Grubbs, D.A. Bansleben, Science 287
(2000) 460–464.
[39] N.T. Allen, B.L. Goodall, L.H. McIntosh III, US Patent US2007049712A1.
[40] N.T. Allen, B.L. Goodall, L.H. McIntosh III, European Patent EP1760086A2.
[41] L.H. McIntosh III, N.T. Allen, T.C. Kirk, B.L. Goodall, Canadian Patent
CA2556356A1.
[42] B.L. Goodall, N.T. Allen, D.M. Conner, T.C. Kirk, L.H.I.I.I. McIntosh, Polym. Prepr.
48 (2007) 202.
[43] J.C. Randall, J. Macromol. Sci., Rev. Macromol. Chem. Phys. C29 (1989) 201–
317.
[22] K.M. Skupov, P.R.M. Marella, M. Simard, G.P.A. Yap, M. Allen, D. Conner, B.L.
Goodall, J.P. Claverie, Macromol. Rapid Commun. 28 (2007) 2033–2038.
[23] K.M. Skupov, L. Piche, J.P. Claverie, Macromolecules 41 (2008) 2309–2310.
[24] S. Luo, J. Vela, G.R. Lief, R.F. Jordan, J. Am. Chem. Soc. 129 (2007) 8946–8947.
[25] J. Vela, G.R. Lief, Z. Shen, R.F. Jordan, Organometallics 26 (2007) 6624–6635.
[26] W. Weng, Z. Shen, R.F. Jordan, J. Am. Chem. Soc. 129 (2007) 15450–15451.
[27] S. Liu, S. Borkar, D. Newsham, H. Yennawar, A. Sen, Organometallics 26 (2007)
210–216.
[28] D.K. Newsham, S. Borkar, A. Sen, D.M. Conner, B.L. Goodall, Organometallics 26
(2007) 3636–3638.
[44] D.E. Axelson, G.C. Levy, L. Mandelkern, Macromolecules 12 (1979) 41–52.