Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 5, pp. 895−900.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
N.B. Valetova, I.S. Il’ichev, D.F. Grishin, 2010, published in Zhurnal Prikladnoi Khimii, 2010, Vol. 83, No. 5, pp. 843−848.
AND POLYMERIC MATERIALS
Polymerization of Styrene and Methyl Methacrylate
Using a Catalytic System Based
on 1,2-Bis(diphenylphosphino)ethanenickel Dibromide
N. B. Valetova, I. S. Il’ichev, and D. F. Grishin
Research Institute of Chemistry, Lobachevsky Nizhni Novgorod State University, Nizhni Novgorod, Russia
Received November 16, 2009
Abstract—Speciﬁ c features of homo- and copolymerization of styrene and methyl methacrylate in the presence
of the catalytic system NiBr
dppe/PhI/Zn were studied.
Transition metal complexes have been widely used
recently for controlling the chain propagation under
conditions of radical initiation, including controlled
synthesis of macromolecules [1, 2]. In particular, the use
of nickel salts, including nickel phosphine complexes,
makes it possible to perform in some cases controlled
radical polymerization of methyl methacrylate
(MMA) [3–5], butyl acrylate [4, 5], methyl acrylate
, and styrene (SТ) , and also copolymerization
of certain (meth)acrylic monomers [4, 5] at relatively
low temperatures (60–85°С). In this case, as a rule,
nickel complexes with monodentate ligands such as
[3, 4] and NiBr
 are used as
catalysts. Data on the effect of nickel complexes with
bidentate phosphine ligands on polymerization of vinyl
monomers are lacking.
At the same time, in many cases speciﬁ cally the
ligand surrounding of the central atom exerts a noticeable
effect on the reactivity of transition metal complexes [7,
8]. Nickel compounds are not exceptions. For example,
replacement of monodentate triphenylphosphine
P) as ligand in nickel complexes by bidentate
1,2-bis(diphenylphosphino)ethane (dppe) enhances the
activity and selectivity of the catalysts in the Kumada–
Corriu reaction [9, 10]. On the contrary, the presence
of the dppe ligand in the nickel complex NiX
decreases the catalytic activity of the complex in
addition and insertion of alkenes .
The binary catalyst NiX
ethane]/zinc is frequently used for coupling of aryl
halides with arenecarbaldehydes [12, 13] and with
areneboronic acids , and also in ring formation
reactions involving diynes  and cycloalkenes 
and in other chemical processes [17, 18].
As we showed previously [19–21], the system
/Zn in combination with iodobenzene
makes it possible to perform polymerization of methyl
methacrylate and styrene in the controlled mode up to
high conversions, which are attained within 5–10 h at 65–
70°С. We found that the metal complex catalyst directly
participates in the chain propagation step and noticeably
affects the dependence of the copolymer composition on
the composition of the monomer mixture.
This paper deals with the polymerization and
copolymerization of methyl methacrylate and styrene
in the presence of the catalyst NiBr
a bidentate ligand. Also we made a comparative analysis
of the activity of the nickel complexes with mono- and
bidentate organophosphorus ligands in homo- and
copolymerization of vinyl monomers.
Ethanol was distilled at atmospheric pressure;
iodobenzene, ethyl acetate, chloroform, and hexane