PALLADIUM COMPLEXES PRESENT DURING THE CATALYTIC REDUCTION OF NO TO N2O

The identity of a palladium chloronitrosyl complex, active in the cata lytic reduction of NO to N2O, has been examined in aqueous and nonaque ous media. Stoichiometry experiments for its formation from [PdCl4](2- ) show the presence of one bound nitrosyl group per palladium and the requirement of a one-electron reductant, provided by CuCl. Work in non -aqueous solvents identified [Pd2Cl4(NO)(2)](2-) as a key intermediate , although in aqueous 2 M HCl the monomeric form [PdCl3(NO)](2-) is su ggested to predominate, according to the equilibrium: [Pd2Cl4(NO)(2)]( 2-) +2Cl(-) reversible arrow 2[PdCl3(NO)](2-). The [Ph(4)As](2)[Pd2Cl4 (NO)(2)] complex could be oxidized to the stable compound [Ph(4)As](2) [Pd2Cl4(NO2)(2)], whose structure was determined by single crystal X-r ay diffraction.