Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
2 Living Polymerization of Propene with a Chelating Diamidodimethyltitanium . . . . . . . . . 145
2.1 Activation with dMMAO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
2.2 Activation with SiO 2 -Supported dMMAO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
3 Living Polymerization of Propene with ansa-Dimethysilylene(fluorenyl)(amido)dimethyltitanium Activated with dMMAO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
3.1 Effect of Solvents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
3.2 Substituent Effects of Fluorenyl Ligand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
3.3 Synthesis of Stereo-Block PP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
4 Living Polymerization of Norbornene with ansa-Dimethysilylene(fluorenyl)(amido)dimethyltitanium Activated with dMMAO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
4.1 Homopolymerization of Norbornene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
4.2 Random Copolymerization of Norbornene and 1-Alkene . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
4.3 Block Copolymerization of Norbornene and 1-Alkene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
5 Conclusion . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . 159
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
1 Introduction
Development of metallocene catalysts, which is strongly owing to the finding of
methylaluminoxane (MAO) as a cocatalyst [1], has enabled us to produce a variety
of uniform olefin copolymers as well as to control the stereoregularity of
polyolefins [2, 3]. The success of metallocene catalysts stimulated the research on
transition metal complexes for olefin polymerization [4, 5], so-called single-site
catalysts, resulting in various transition metal complexes for living polymerization
of olefins [6, 7]. Although several cocatalysts such as B(C 6 F 5 ) 3 , Ph 3 CB(C 6 F 5 ) 4 , and
PhMe 2 NHB(C 6 F 5 ) 4 have been developed [8], MAO is still one of the most important cocatalyst because of its universality for various transition metal complexes.
When MAO, which is the condensation product of water and Me 3 Al and is
usually supplied as a toluene solution, is used as a cocatalyst for living polymerization, Me 3 Al remaining in the toluene solution should be removed to prevent the
chain transfer via transmetalation. However, the removal of Me 3 Al from MAO
significantly decreases the solubility of MAO, even in toluene. Modified MAO
(MMAO), which is the condensation product between water and the mixture of
Me 3 Al and
i
Bu 3 Al, possesses good solubility in aliphatic hydrocarbons. We therefore prepared R 3 Al-free MMAO and applied it as a cocatalyst [9]. Hereafter, dMAO
and dMMAO denote Me 3 Al-free MAO and R 3 Al-free MMAO, respectively. This
144
T. Shiono
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
2 Living Polymerization of Propene with a Chelating Diamidodimethyltitanium . . . . . . . . . 145
2.1 Activation with dMMAO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
2.2 Activation with SiO 2 -Supported dMMAO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
3 Living Polymerization of Propene with ansa-Dimethysilylene(fluorenyl)(amido)dimethyltitanium Activated with dMMAO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
3.1 Effect of Solvents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
3.2 Substituent Effects of Fluorenyl Ligand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
3.3 Synthesis of Stereo-Block PP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
4 Living Polymerization of Norbornene with ansa-Dimethysilylene(fluorenyl)(amido)dimethyltitanium Activated with dMMAO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
4.1 Homopolymerization of Norbornene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
4.2 Random Copolymerization of Norbornene and 1-Alkene . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
4.3 Block Copolymerization of Norbornene and 1-Alkene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
5 Conclusion . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . 159
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
1 Introduction
Development of metallocene catalysts, which is strongly owing to the finding of
methylaluminoxane (MAO) as a cocatalyst [1], has enabled us to produce a variety
of uniform olefin copolymers as well as to control the stereoregularity of
polyolefins [2, 3]. The success of metallocene catalysts stimulated the research on
transition metal complexes for olefin polymerization [4, 5], so-called single-site
catalysts, resulting in various transition metal complexes for living polymerization
of olefins [6, 7]. Although several cocatalysts such as B(C 6 F 5 ) 3 , Ph 3 CB(C 6 F 5 ) 4 , and
PhMe 2 NHB(C 6 F 5 ) 4 have been developed [8], MAO is still one of the most important cocatalyst because of its universality for various transition metal complexes.
When MAO, which is the condensation product of water and Me 3 Al and is
usually supplied as a toluene solution, is used as a cocatalyst for living polymerization, Me 3 Al remaining in the toluene solution should be removed to prevent the
chain transfer via transmetalation. However, the removal of Me 3 Al from MAO
significantly decreases the solubility of MAO, even in toluene. Modified MAO
(MMAO), which is the condensation product between water and the mixture of
Me 3 Al and
i
Bu 3 Al, possesses good solubility in aliphatic hydrocarbons. We therefore prepared R 3 Al-free MMAO and applied it as a cocatalyst [9]. Hereafter, dMAO
and dMMAO denote Me 3 Al-free MAO and R 3 Al-free MMAO, respectively. This
144
T. Shiono