Abstract

The study of the [PtBr(4)](2-) reactivity with hexene and aniline in highly ionic (Bu(4)P)Br/CH(2)Br(2) media has been studied from a Kinetico-Mechanistic perspective. The results indicate bromide ion association to the square-planar starting material to produce a stable diamagnetic compound that can be described as an ion pair of a [PtBr(5)](3-) square-pyramidal complex stabilized by several phosphonium countercations. While this species reacts rapidly with aniline, producing the known square-planar complex [PtBr(3)(PhNH(2))](-) with release of the apical bromide of the square-pyramidal intermediate, the reaction with hexene, producing the square-planar [PtBr(3)(hexene)](-) complex, is much slower. The thermal and pressure activation parameters determined for these processes fully agree with the proposed reactivity. The gross features of the platinum-catalyzed hydroamination mechanism, occurring via much higher energy transition states, are not necessarily altered by these new findings, given the fact that all ligand exchange reactions occur with relatively low activation barriers. Nevertheless, the nature of the catalyst resting state needs revision as demonstrated. The importance of explicitly considering the solvent for reactions conducted in noninnocent highly organized media is also highlighted.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.