Abstract:

Size controlled organic phase soluble cyano-bridged bimetallic coordination polymer nanoparticles made of Mⁿ⁺ and [M′(CN)₆]³⁻ (with Mⁿ⁺ = Mn²⁺, Ni²⁺, Fe²⁺, Eu³⁺, Tb³⁺, Sm³⁺ and M′ = Fe³⁺, Cr³⁺) were synthesized by using oleic acid and trialkylamines or a triarylamine as stabilizing agents. The obtained nanoparticles were studied by transmission electronic microscopy (TEM), infrared and electronic spectroscopy, X-ray diffraction, and magnetic measurements. These analyses revealed the formation of spherical metallic cyano-bridged nanoparticles with sizes in the range of 2–5 nm depending on the nature of the metal ion used. The magnetic studies of these colloidal solutions revealed the presence of a pure superparamagnetic regime for the nanoparticles based on [Cr(CN)₆]³⁻ and a collective regime caused by weak dipolar interparticle interactions for the nanoparticles based on [Fe(CN)₆]³⁻.