Olefin complexes electron density distribution

A similar reaction was not observed for 4-pentene-l-ol. It should be noted that a Pt(III) dimer complex is released after the reaction in Eq. (18), which is in contrast to the release of olefin and a Pt(II) dimer complex in aqueous solution by reductive elimination (Eq. (16)). The difference of such reactivity depending on the alkyl and the solvent would be caused by the difference of the electron density of the a-carbon atom and the dipole structure along the Pt-Pt bond in the solvents of different polarities. In aprotic organic solvent, the electron distribution along the Pt-Pt bond would be less polar, i.e., close to... 

The polymerization mechanism of a-olefins is often defined as anionic-coordinated. The term anionic , if intended to denote an asymmetric electronic distribution on the M—bond with a higher electronic density on P than on M, seems justified (see hydrolysis with tritiated Bronsted acids. Section 4). The term coordinated is used to stress the assumption that, like other reactions catalyzed by complexes of transition metals, propylene should coordinate at the transition metal before insertion into the M —P bond. Polymerization would then take... 

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