Direct Transformation into Silver Nanoparticles via Thermal Decomposition of Oxalate-Bridging Silver Oleylamine Complexes

Silver(I) oxalate, Ag2(C2O4), reacts with two equivalents of oleylamine (Ag:oleylamine = 1:1 mole/mole) to form an oxalate-bridged silver-oleylamine complex, [(oleylamine)Ag(micro-C2O4)Ag(oleylamine)]. The precursor complex is thermally decomposed at approximately 150 degrees C with CO2 evolution to produce Ag nanoparticles with approximately 11 nm dimension. The Ag nanoparticles contain approximately 12 wt% of oleylamines as the surface stabilizer. In the synthetic mechanism, the oxalate ligand acts as a two-electron reducing agent. The precursor complex is directly transformed into oleylamine-stabilized Ag nanoparticles in high yields of more than 80% without any additional synthetic organic solvents and reducing agents.