Optical spectra of Pd-561 nanoclusters in aqueous solutions

Optical absorption spectra of aqueous solutions of the giant cluster Pd(561 )Phen(60)(OAc)(180) (1) were studied in air and after treatment with H-2. T he results obtained were compared with the corresponding data for 2-4-nm na noparticles of colloidal palladium prepared by the radiochemical and chemic al reduction of the Pd-II complexes in aqueous solutions. The optical spect ra of cluster 1 and nanoparticles of colloidal palladium are of the same na ture and are caused by the light absorption by free electrons in the metal.