Soluble ligand-stabilized cyano-bridged coordination polymer nanoparticles

Size controlled organic phase soluble cyano-bridged bimetallic coordination polymer nanoparticles made of M"(+) 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-).