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Cycloolefin/carbon monoxide

The same group of coordination polymerisations in which alkene undergoes re complex formation with the metal atom includes the copolymerisation of ethylene, a-olefins, cycloolefins and styrene with carbon monoxide in the presence of transition metal-based catalysts [54-58], In this case, however, the carbon monoxide comonomer is complexed with the transition metal via the carbon atom. Coordination bond formation involves the overlapping of the carbon monoxide weakly antibonding and localised mostly at the carbon atom a orbital (electron pair at the carbon atom) with the unoccupied hybridised metal orbitals and the overlapping of the filled metal dz orbitals with the carbon monoxide re -antibonding orbital (re-donor re bond) [59], The carbon monoxide coordination with the transition metal is shown in Figure 2.2. [Pg.11]

Ever since their original discoveries, Ziegler Natta catalysts and Phillips catalysts have been used for both the homopolymerisation and the copolymerisation of olefins. Moreover, Ziegler-Natta catalysts also allowed the copolymerisation of olefins with vinylaromatic monomers, conjugated dienes and cycloolefins. Other coordination catalysts such as group 8 metal compounds, especially cationic Pd(II) complexes, enabled the alternating copolymerisation of olefins and carbon monoxide [2,29,30,37,43,46,241,448 450],... [Pg.179]

Preferred olefins in the polymerisation are one or more of ethylene, propylene, 1-butene, 2-butene, 1-hexene, 1-octene, 1-pentene, 1-tetradecene, norbornene and cyclopentene, with ethylene, propylene and cyclopentene. Other monomers that may be used with these catalysts (when it is a Pd(II) complex) to form copolymers with olefins and selected cycloolefins are carbon monoxide (CO) and vinyl ketones of the general formula H2C=CHC(0)R. Carbon monoxide forms alternating copolymers with the various olefins and cycloolefins. [Pg.219]

Analogously to ethylene-carbon monoxide copolymers, alternating copolymers between cycloolefins such as norbornene and carbon monoxide have been synthesised using cationic Pd(II) complexes modified by phosphorus ligands such as [Pd(MeCN)n(PPh)4 J[BF4]2( = 1,2,3) [27]. General requirements for the... [Pg.335]

Alternating copolymers of cycloolefins and carbon monoxide have also been obtained in the case of cyclopentene the copolymerisations were run using cationic Pd(II) complexes modified by an achiral l,3-bis(diphenylphosphino)-propane ligand or a chiral 2,4-bis(diphenylphosphino)pentane ligand. [Pg.336]

Subjects specifically excluded are cycloolefin polymerizations catalyzed by naked nickel catalysts, palladium-catalyzed ethylene/carbon monoxide alternating copolymerizations, metathesis polymerizations of cyclic olefins, and diene polymerizations... [Pg.304]

Recently, Ni- and Pd-based catalysts have been developed in order to copolymerize nonpolar ethylene, 1-olefins or cycloolefins with polar comonomers, such as carbon monoxide and methyl acrylate or 1-olefins, containing polar groups which are separated by at least two methylene... [Pg.915]


See other pages where Cycloolefin/carbon monoxide is mentioned: [Pg.179]    [Pg.335]    [Pg.216]    [Pg.67]   


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