Isolation and characterisation by X-ray studies of palladium μ2-nitrosyl clusters in the reduction of nitric acid by carbon monoxide mediated by palladium acetate

In the reduction by CO of HNO3 to NO, mediated by [Pd 3(O2CMe)6] in acetic acid, [Pd 3(O2CMe)5(η2-NO2)] (1) is formed first, but is converted under the reaction conditions into the known cluster [Pd4(O2CMe)6(μ2-NO) 2] (2); slow crystallization of (1) from wet benzene and pentane gives (2) and [Pd6(O2CMe)8(μ2-NO) 2] (3), the structures of (1) and (3) having been determined by X-ray crystallography.