Shape-and size-controlled Ag nanoparticles stabilized by in situ generated secondary amines

Abstract Silver amides such as AgN i Pr 2 and AgN(SiMe 3 ) 2 have been employed successfully as precursors for the yield synthesis of silver nanoparticles under mild conditions of dihydrogen gas reduction (2 atm) in organic media. Transmission electron microscopy (TEM) showed the formation of silver nanoparticles with FCC structure, variously sized from 26 to 35 nm for AgN i Pr 2 and from 14 to 86 nm for AgN(SiMe 3 ) 2 , the synthesis could take place in absence of added stabilizers due to the in situ formation of secondary amines from the reaction of dihydrogen gas with the amide ligands of the silver precursor. Indeed, the presence of HNR 2 (R =  i Pr 2 , N(SiMe 3 ) 2 ) on the surface of the nanoparticle was confirmed by spectroscopic means. Finally, the addition of ethylenediamine as additional capping agent allowed not only the control of the structural characteristics of the resulting Ag nanoparticles (well-dispersed with spherical shape), but that regarding the nanoparticle size as it inhibited overgrowth, limiting it to ca . 25 nm.