Effects of water as a solvent on the kinetics and equilibria of platinum(II)-alkene complexes
Dudziak, Jeffrey A.
MetadataShow full item record
In order to further understand the effects of water as a solvent in organometallic reactions, the lability of η 2 -alkenes coordinated to platinum(II) phosphine complexes has been studied in chloroform and water/methanol as a means of comparing the effects that solvent choice has on alkene exchange kinetics and complex stability. 1 H NMR techniques with both deuterated chloroform and a deuterium oxide/deuterated methanol mixture as solvent systems were used at temperatures as low as -50°C. Reactions of cis- PtCl 2 L(η 2 -C 3 H 6 ) [L=PPh 3 (triphenylphosphine), TPPTS (tris( m- sulfonatophenyl)phosphine)] with ethylene to form cis- PtCl 2 L(η 2 -C 2 H 4 ) were observed with dependence on the rate by starting platinum complex and ethylene. The role of water in this reaction, including its effect on the equilibrium, is discussed. The equilibrium constant shows preference for coordination of ethylene and the temperature dependence indicates the reaction is entropy controlled.