The syntheses of the triphosphine ligands RP(CH2CH2PR′2)2 (R = CH2CH2CH2OH and R′ = Et, HOPetpE; R = Ph and R′ = CH2CH2P(O)(OEt)2, etpEPO; R = Me2N and R′ = Et, MNetpE; R = i-Pr2N and R′ = Et, IPNetpE; R = Ph and R′ = NMe2, etpMN) are described. The reaction of [Pd(CH3CN)4](BF4)2 with these ligands forms [Pd(triphosphine)(CH3CN)](BF4)2 complexes that are all water soluble with the exception of [Pd(IPNeIpE)(CH3-CN)](BF4)2. The labile acetonitrile ligands are easily substituted by triethylphosphine to form [Pd(triphosphine)-(PEt3)](BF4)2 complexes. The triethylphosphine complexes undergo quasi-reversible two-electron reductions while the corresponding acetonitrile complexes undergo two, closely spaced, irreversible, one-electron reductions. [Pd-(HOPetpE)(CH3CN)](BF4)2 and [Pd(etpEPO)(CH3CN)](BF4)2 are catalysts for the electrochemical reduction of CO2 to CO in both dimethylformamide and buffered aqueous solutions. Kinetic studies are reported for [Pd-(HOPetpE)(CH3CN)](BF4)2 in dimethylformamide.
|Number of pages||10|
|Publication status||Published - 1995|
ASJC Scopus subject areas
- Inorganic Chemistry